Perceptions of being a learner: an investigation into how first year Journalism students at a South African university construct themselves as learners
- Authors: Lunga, Carolyne Mande
- Date: 2015
- Subjects: Journalism -- Study and teaching (Higher) -- South Africa , Students -- Attitudes , Students -- Self-rating of -- South Africa , Discourse analysis, Narrative , Active learning -- South Africa , Learning -- Evaluation , Learning, Psychology of , College freshmen -- South Africa
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1332 , http://hdl.handle.net/10962/d1020026
- Description: The aim of the research reported in this document was to explore the ways in which first year Journalism students at a South African University construct themselves as learners. The research adopted a case study approach of purposively selected first year journalism students. In exploring this area, focus group and individual in-depth interviewing were employed which illuminated important aspects of learner identity construction. In order to make sense of these self-constructions, the research was located in the larger debates on discourse as espoused by Michel Foucault who argues that discourse constructs subjectivities. The research demonstrated that there were various discourses at play which influenced how these learners spoke and behaved. The influence of these discourses on learners' experiences varied at different times of the year. For example, the awarding of the Duly Performed (DP) certificate for students who met the minimum attendance and work requirements of a particular course, the giving of tests, exercises and examinations were some of the technologies that 'forced' students into compliance. In terms of identity formation, the heterogeneous nature of 'being' a journalism 'student' revealed that the different discourses at play influenced learner behaviour and that their identities continued to change over the year. Doing additional subjects such as Sociology, Drama, Art History and others at the same time as Journalism and Media Studies also meant that the learners had to negotiate the differing role requirements.
- Full Text:
- Date Issued: 2015
- Authors: Lunga, Carolyne Mande
- Date: 2015
- Subjects: Journalism -- Study and teaching (Higher) -- South Africa , Students -- Attitudes , Students -- Self-rating of -- South Africa , Discourse analysis, Narrative , Active learning -- South Africa , Learning -- Evaluation , Learning, Psychology of , College freshmen -- South Africa
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1332 , http://hdl.handle.net/10962/d1020026
- Description: The aim of the research reported in this document was to explore the ways in which first year Journalism students at a South African University construct themselves as learners. The research adopted a case study approach of purposively selected first year journalism students. In exploring this area, focus group and individual in-depth interviewing were employed which illuminated important aspects of learner identity construction. In order to make sense of these self-constructions, the research was located in the larger debates on discourse as espoused by Michel Foucault who argues that discourse constructs subjectivities. The research demonstrated that there were various discourses at play which influenced how these learners spoke and behaved. The influence of these discourses on learners' experiences varied at different times of the year. For example, the awarding of the Duly Performed (DP) certificate for students who met the minimum attendance and work requirements of a particular course, the giving of tests, exercises and examinations were some of the technologies that 'forced' students into compliance. In terms of identity formation, the heterogeneous nature of 'being' a journalism 'student' revealed that the different discourses at play influenced learner behaviour and that their identities continued to change over the year. Doing additional subjects such as Sociology, Drama, Art History and others at the same time as Journalism and Media Studies also meant that the learners had to negotiate the differing role requirements.
- Full Text:
- Date Issued: 2015
Performance management of health professionals : an evaluation research study of health services in the subdistrict of Buffalo City in the Provincial Department of Health in the Eastern Cape
- Authors: Booi, Mlungisi Wellington
- Date: 2015
- Subjects: South Africa -- Department of Health , Batho Pele (Program) , Public health personnel -- South Africa -- Buffalo City , Employees -- Rating of -- South Africa -- Buffalo City , Public health -- South Africa -- Buffalo City -- Evaluation , Customer services -- South Africa -- Buffalo City -- Evaluation , Employees -- Training of -- South Africa -- Buffalo City , Employee-management relations in government -- South Africa -- Buffalo City
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:859 , http://hdl.handle.net/10962/d1020017
- Description: Integrative Summary In 1997 the Minister of Public Service and Administration of South Africa, Zola Skweyiya, introduced the White Paper on Transforming Public Service Delivery(Department of Public Service and Administration(DPSA,1997: 1). It was premised on what was called Batho Pele (DPSA, 1997: 9), giving effect to Section 197 of the Constitution, Act 108 of 1996 as amended. A linkage to performance management can be found from the assertion made in the White Paper that in future the Batho Pele would form the basis of any assessment of the performance of individual staff and that would contribute to improving the delivery of service (DPSA, 1997:16). Another factor that contributed to the utilisation of a performance management system was the recommendation put forward by the Public Service Commission of South Africa( PSC,2004: 16),that called for public institutions to adopt a clear, comprehensive performance management and evaluation framework for the delivery of public service. That was expected to turn around the ailing public institutions whose record of serving the public with pride and dignity was on the decline. The research aim was to evaluate the effectiveness of the performance management system in creating and resolving role conflict with health professionals employed by the Buffalo City sub-district. The research goal was divided into three objectives, namely: evaluation of the effectiveness of the performance management system as a managerial tool for health managers to manage their subordinates including both professional and support staff, evaluation of the effectiveness of the performance system from the perspective of the health professional as a subordinate and to analyze the functioning and effectiveness of the system in creating and resolving role conflict between professional conduct and organisational requirements. The respondents noted that the implementation of the system was not matched with appointment at managerial level with officials having relevant managerial capacity. Further to that resources at the coal face of service delivery continued to deteriorate and became very scarce and there is no documented proof that has been found of an effort made to check the compatibility of the system to health professionals. The literature identified negative effects that have emanated from the implementation of the performance management system. The study was conducted by interviewing health professionals from the entry level to the management level within the Buffalo City sub-district from three mini hospitals or Health Care Centres. The respondents indicated that there are positives that have been achieved by the implementation of the system, such as the skills gap identification as well as specific targets contained in annual performance contracts. These targets help motivate health professional to focus on that particular direction of activities. Unfortunately it has been clearly documented that the performance management system has also contributed to the development of role conflict in a number of professionals. It has been documented that the system has not been crafted with a health professional in mind and, as such, appears to favour quantity rather than quality of health services as advocated by the codes of practice of different health professionals. There are a number of recommendations that were put forward by the respondents to try to salvage the system and in mitigation of the identified negative factors. For the improvement of the system, the Eastern Cape Provincial Department of Health has to firstly customise the annual contracts to contain only the fundamental information. Secondly need to improve the transparency pertaining to financial pressures facing the Health Department. Thirdly the provision of essential enablers, need to be prioritised. Fourthly there is a need to upgrade the system to incorporate 360 degree feedback. Further research recommendations include a bigger sample incorporating different research methods and to also incorporate searches for measures that can be implemented to improve the system to be more relevant to health professionals. This document is organised and presented in three sections. The first section is the evaluation report with a review of literature, research methodology, findings, discussion and conclusion. The second section is where an indepth literature review is located and the last section details the research methodology.
- Full Text:
- Date Issued: 2015
- Authors: Booi, Mlungisi Wellington
- Date: 2015
- Subjects: South Africa -- Department of Health , Batho Pele (Program) , Public health personnel -- South Africa -- Buffalo City , Employees -- Rating of -- South Africa -- Buffalo City , Public health -- South Africa -- Buffalo City -- Evaluation , Customer services -- South Africa -- Buffalo City -- Evaluation , Employees -- Training of -- South Africa -- Buffalo City , Employee-management relations in government -- South Africa -- Buffalo City
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:859 , http://hdl.handle.net/10962/d1020017
- Description: Integrative Summary In 1997 the Minister of Public Service and Administration of South Africa, Zola Skweyiya, introduced the White Paper on Transforming Public Service Delivery(Department of Public Service and Administration(DPSA,1997: 1). It was premised on what was called Batho Pele (DPSA, 1997: 9), giving effect to Section 197 of the Constitution, Act 108 of 1996 as amended. A linkage to performance management can be found from the assertion made in the White Paper that in future the Batho Pele would form the basis of any assessment of the performance of individual staff and that would contribute to improving the delivery of service (DPSA, 1997:16). Another factor that contributed to the utilisation of a performance management system was the recommendation put forward by the Public Service Commission of South Africa( PSC,2004: 16),that called for public institutions to adopt a clear, comprehensive performance management and evaluation framework for the delivery of public service. That was expected to turn around the ailing public institutions whose record of serving the public with pride and dignity was on the decline. The research aim was to evaluate the effectiveness of the performance management system in creating and resolving role conflict with health professionals employed by the Buffalo City sub-district. The research goal was divided into three objectives, namely: evaluation of the effectiveness of the performance management system as a managerial tool for health managers to manage their subordinates including both professional and support staff, evaluation of the effectiveness of the performance system from the perspective of the health professional as a subordinate and to analyze the functioning and effectiveness of the system in creating and resolving role conflict between professional conduct and organisational requirements. The respondents noted that the implementation of the system was not matched with appointment at managerial level with officials having relevant managerial capacity. Further to that resources at the coal face of service delivery continued to deteriorate and became very scarce and there is no documented proof that has been found of an effort made to check the compatibility of the system to health professionals. The literature identified negative effects that have emanated from the implementation of the performance management system. The study was conducted by interviewing health professionals from the entry level to the management level within the Buffalo City sub-district from three mini hospitals or Health Care Centres. The respondents indicated that there are positives that have been achieved by the implementation of the system, such as the skills gap identification as well as specific targets contained in annual performance contracts. These targets help motivate health professional to focus on that particular direction of activities. Unfortunately it has been clearly documented that the performance management system has also contributed to the development of role conflict in a number of professionals. It has been documented that the system has not been crafted with a health professional in mind and, as such, appears to favour quantity rather than quality of health services as advocated by the codes of practice of different health professionals. There are a number of recommendations that were put forward by the respondents to try to salvage the system and in mitigation of the identified negative factors. For the improvement of the system, the Eastern Cape Provincial Department of Health has to firstly customise the annual contracts to contain only the fundamental information. Secondly need to improve the transparency pertaining to financial pressures facing the Health Department. Thirdly the provision of essential enablers, need to be prioritised. Fourthly there is a need to upgrade the system to incorporate 360 degree feedback. Further research recommendations include a bigger sample incorporating different research methods and to also incorporate searches for measures that can be implemented to improve the system to be more relevant to health professionals. This document is organised and presented in three sections. The first section is the evaluation report with a review of literature, research methodology, findings, discussion and conclusion. The second section is where an indepth literature review is located and the last section details the research methodology.
- Full Text:
- Date Issued: 2015
Performing whiteness; representing otherness : Hugh Tracey and African music
- Authors: Coetzee, Paulette June
- Date: 2015
- Subjects: Tracey, Hugh , Music -- Africa , International Library of African Music , Ethnomusicology -- Africa , Ethnomusicologists -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:2327 , http://hdl.handle.net/10962/d1016502
- Description: This thesis provides a critical study of texts associated with Hugh Tracey (1903–1977). Tracey is well-known for his work in African music studies, particularly for his major contribution to the recorded archive of musical sound in sub-Saharan Africa and his founding of the International Library of African Music (ILAM) in 1954. My reading of him is informed by a postcolonial perspective, whiteness studies and African scholarship on ways in which constructions of African identity and tradition have been shaped by the colonial archive. In my view, Tracey was part of a mid-twentieth century movement which sought to marshal positive representations of traditional African culture in the interest of maintaining and strengthening colonial rule. While his recording project may have fostered inclusion through creating spaces for indigenous musicians to be heard, it also functioned to promote racist exclusion in the manner of its production, distribution and claims to expertise. Moreover, his initial strategy for ILAM’s sustainability targeted colonial government and industry as primary clients, with the promise that promoting traditional music as a means of entertainment and self-expression for black subjects and workers would ease administration and reduce conflict. I believe that it is important to acknowledge and interrogate the problematic racial attitudes and practices associated with the history of Tracey’s archive – not to undermine its significance in any way but to allow it to be better understood and used more productively in the future.
- Full Text:
- Date Issued: 2015
- Authors: Coetzee, Paulette June
- Date: 2015
- Subjects: Tracey, Hugh , Music -- Africa , International Library of African Music , Ethnomusicology -- Africa , Ethnomusicologists -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:2327 , http://hdl.handle.net/10962/d1016502
- Description: This thesis provides a critical study of texts associated with Hugh Tracey (1903–1977). Tracey is well-known for his work in African music studies, particularly for his major contribution to the recorded archive of musical sound in sub-Saharan Africa and his founding of the International Library of African Music (ILAM) in 1954. My reading of him is informed by a postcolonial perspective, whiteness studies and African scholarship on ways in which constructions of African identity and tradition have been shaped by the colonial archive. In my view, Tracey was part of a mid-twentieth century movement which sought to marshal positive representations of traditional African culture in the interest of maintaining and strengthening colonial rule. While his recording project may have fostered inclusion through creating spaces for indigenous musicians to be heard, it also functioned to promote racist exclusion in the manner of its production, distribution and claims to expertise. Moreover, his initial strategy for ILAM’s sustainability targeted colonial government and industry as primary clients, with the promise that promoting traditional music as a means of entertainment and self-expression for black subjects and workers would ease administration and reduce conflict. I believe that it is important to acknowledge and interrogate the problematic racial attitudes and practices associated with the history of Tracey’s archive – not to undermine its significance in any way but to allow it to be better understood and used more productively in the future.
- Full Text:
- Date Issued: 2015
Photo-physicochemical studies and photodynamic therapy activity of indium and gallium phthalocyanines
- Tshangana, Charmaine Sesethu
- Authors: Tshangana, Charmaine Sesethu
- Date: 2015
- Subjects: Quantum dots , Nanoparticles , Photochemotherapy , Phthalocyanines
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4548 , http://hdl.handle.net/10962/d1017928
- Description: The potential toxicity of seven different types of quantum dots without shell (L-cysteine-CdTe, TGA-CdTe, MPA-CdTe, TGA-CdSe) and with the shell (GSH-CdSe@ZnS, GSH-CdTe@ZnS,) with different capping agents were evaluated. The growth inhibitory effects of the various quantum dots on human pancreatic BON cancerous cells were determined. The least cytotoxic of the various quantum dots synthesized and the one displaying the lowest growth inhibitory potential and no embryotoxicity was determined to be the GSH-CdSe@ZnS quantum dots. The GSH-CdSe@ZnS quantum dots were then conjugated to gallium, aluminium and indium octacarboxy phthalocyanine and the photophysical behaviour of the conjugates studied for potential use in photodynamic therapy and imaging applications. The sizes, morphology, thermal stability and confirmation of successful conjugation was determined using X-ray diffraction (XRD), transmission electron microscopy (TEM), thermogravimetric analysis (TGA) and Fourier transform infrared spectroscopy (FTIR), respectively. The study was extended by conjugating amino functionalized magnetic nanoparticles (Fe₃O₄) to indium octacarboxy phthalocyanine to study the photophysical behaviour of the conjugate as a potential bi-functional anti-cancer agent (hyperthermia and photodynamic therapy applications). A three-in-one multifunctional nanocomposite comprising of the quantum dots, magnetic nanoparticles and indium octacarboxy phthalocyanine was developed with the aim of developing a multifunctional composite that is able detect, monitor and treat cancer. All conjugates showed improved and enhanced photophysical behaviour. Finally, GSH-CdSe@ZnS conjugated to aluminium octacarboxy phthalocyanine was applied in human pancreatic carcinoid BON cells. The conjugates induced cell death dose-dependently.
- Full Text:
- Date Issued: 2015
- Authors: Tshangana, Charmaine Sesethu
- Date: 2015
- Subjects: Quantum dots , Nanoparticles , Photochemotherapy , Phthalocyanines
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4548 , http://hdl.handle.net/10962/d1017928
- Description: The potential toxicity of seven different types of quantum dots without shell (L-cysteine-CdTe, TGA-CdTe, MPA-CdTe, TGA-CdSe) and with the shell (GSH-CdSe@ZnS, GSH-CdTe@ZnS,) with different capping agents were evaluated. The growth inhibitory effects of the various quantum dots on human pancreatic BON cancerous cells were determined. The least cytotoxic of the various quantum dots synthesized and the one displaying the lowest growth inhibitory potential and no embryotoxicity was determined to be the GSH-CdSe@ZnS quantum dots. The GSH-CdSe@ZnS quantum dots were then conjugated to gallium, aluminium and indium octacarboxy phthalocyanine and the photophysical behaviour of the conjugates studied for potential use in photodynamic therapy and imaging applications. The sizes, morphology, thermal stability and confirmation of successful conjugation was determined using X-ray diffraction (XRD), transmission electron microscopy (TEM), thermogravimetric analysis (TGA) and Fourier transform infrared spectroscopy (FTIR), respectively. The study was extended by conjugating amino functionalized magnetic nanoparticles (Fe₃O₄) to indium octacarboxy phthalocyanine to study the photophysical behaviour of the conjugate as a potential bi-functional anti-cancer agent (hyperthermia and photodynamic therapy applications). A three-in-one multifunctional nanocomposite comprising of the quantum dots, magnetic nanoparticles and indium octacarboxy phthalocyanine was developed with the aim of developing a multifunctional composite that is able detect, monitor and treat cancer. All conjugates showed improved and enhanced photophysical behaviour. Finally, GSH-CdSe@ZnS conjugated to aluminium octacarboxy phthalocyanine was applied in human pancreatic carcinoid BON cells. The conjugates induced cell death dose-dependently.
- Full Text:
- Date Issued: 2015
Photodynamic antimicrobial chemotherapy activities of porphyrin- and phthalocyanine-platinum nanoparticle conjugates
- Authors: Managa, Muthumuni Elizabeth
- Date: 2015
- Subjects: Photochemotherapy , Anti-infective agents , Porphyrins , Phthalocyanines , Platinum , Nanoparticles , Bioconjugates , Electrospinning
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4539 , http://hdl.handle.net/10962/d1017919
- Description: This work reports on the conjugation of differently shaped Pt nanoparticles (PtNPs) with ClGa(III) 5,10,15,20-tetrakis-(4-carboxyphenyl) porphyrin (1) as well as chloro - (5,10,15,20-tetrakis (4- (4- carboxy phenycarbonoimidoyl) phenyl) porphyrinato) gallium(III) (2) The work also reports on platination of dihydroxosilicon octacarboxyphthalocyanine (OH)₂SiOCPc (3) to give dihydroxosilicontris(diaquaplatinum)octacarboxyphthalocyanine (OH)₂SiOCPc(Pt)₃ (4). The resulting conjugates were used for photodynamic antimicrobial chemotherapy against S. aureus, E. coli and C. albicans. The degree of photo-inactivation is dependent on concentration of the conjugates, light dose (fluence) and illumination time. The log reduction obtained for 1 when conjugated to cubic PtNPs was 4.64 log (which indicate 99.99 percent of the bacteria have been killed), which is much higher than 3.94 log unit for 1-hexagonal PtNPs and 3.31 log units for 1-unshaped PtNPs. Complex 2 conjugated to hexagonal PtNPs showed 18 nm red shift in the Soret band when compared to 2 alone. Complex 2 and 2-hexagonal PtNPs as well showed promising photodynamic antimicrobial chemotherapy (PACT) activity against S. aureus, E. coli and C. albicans in solution where the log reduction obtained was 4.92, 3.76, and 3.95 respectively for 2-hexagonal PtNPs. The singlet oxygen quantum yields obtained were higher at 0.56 for 2-hexagonl PtNPs in DMF while that of 2 was 0.52 in the same solvent. This resulted in improved PACT activity for 2-hexagonal PtNPs compared to 2. Complex 4 showed slight blue shifting of the absorption spectrum when compared to complex 3 The antimicrobial activity of 4 were promising as the highest log reduction value was observed when compared to the porphyrin conjugates.
- Full Text:
- Date Issued: 2015
- Authors: Managa, Muthumuni Elizabeth
- Date: 2015
- Subjects: Photochemotherapy , Anti-infective agents , Porphyrins , Phthalocyanines , Platinum , Nanoparticles , Bioconjugates , Electrospinning
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4539 , http://hdl.handle.net/10962/d1017919
- Description: This work reports on the conjugation of differently shaped Pt nanoparticles (PtNPs) with ClGa(III) 5,10,15,20-tetrakis-(4-carboxyphenyl) porphyrin (1) as well as chloro - (5,10,15,20-tetrakis (4- (4- carboxy phenycarbonoimidoyl) phenyl) porphyrinato) gallium(III) (2) The work also reports on platination of dihydroxosilicon octacarboxyphthalocyanine (OH)₂SiOCPc (3) to give dihydroxosilicontris(diaquaplatinum)octacarboxyphthalocyanine (OH)₂SiOCPc(Pt)₃ (4). The resulting conjugates were used for photodynamic antimicrobial chemotherapy against S. aureus, E. coli and C. albicans. The degree of photo-inactivation is dependent on concentration of the conjugates, light dose (fluence) and illumination time. The log reduction obtained for 1 when conjugated to cubic PtNPs was 4.64 log (which indicate 99.99 percent of the bacteria have been killed), which is much higher than 3.94 log unit for 1-hexagonal PtNPs and 3.31 log units for 1-unshaped PtNPs. Complex 2 conjugated to hexagonal PtNPs showed 18 nm red shift in the Soret band when compared to 2 alone. Complex 2 and 2-hexagonal PtNPs as well showed promising photodynamic antimicrobial chemotherapy (PACT) activity against S. aureus, E. coli and C. albicans in solution where the log reduction obtained was 4.92, 3.76, and 3.95 respectively for 2-hexagonal PtNPs. The singlet oxygen quantum yields obtained were higher at 0.56 for 2-hexagonl PtNPs in DMF while that of 2 was 0.52 in the same solvent. This resulted in improved PACT activity for 2-hexagonal PtNPs compared to 2. Complex 4 showed slight blue shifting of the absorption spectrum when compared to complex 3 The antimicrobial activity of 4 were promising as the highest log reduction value was observed when compared to the porphyrin conjugates.
- Full Text:
- Date Issued: 2015
Photophysical studies of Zinc phthalocyanine-silica nanoparticles conjugates
- Authors: Fashina, Adedayo
- Date: 2015
- Subjects: Nanoparticles , Phthalocyanines , Zinc , Silica , Photochemistry , Adsorption
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4537 , http://hdl.handle.net/10962/d1017917
- Description: This thesis reports on the synthesis and characterization of both symmetrical and asymmetrical Zinc phthalocyanine complexes. The complexes contained groups such as carboxylic, amino and alkyne for covalent grafting to the surface of silica nanoparticles. The use of symmetrical and asymmetrical complexes was geared towards comparing the non-specific binding of the symmetrical complexes to the specific binding observed in the asymmetrical complexes. The complexes were also doped within the silica matrix and compared to the surface grafted conjugates. The complexes and the conjugates were well characterized with a variety of techniques. The fluorescence lifetimes of the phthalocyanine complexes containing either terminal carboxylic groups or an alkyne group showed a mono-exponential decay while the amino containing phthalocyanine complexes gave a bi-exponential decay. A similar trend was observed for their respective conjugates. Some of the conjugates of the asymmetrical complexes showed a decrease in fluorescence lifetimes and a corresponding decrease in fluorescence quantum yields. The fluorescence quantum yields for all the symmetrical complexes studied showed either an improvement or retained the luminescence of the grafted phthalocyanine complex. Most of the conjugates showed a faster intersystem crossing time in comparison to the complexes alone. The grafted or doped conjugates containing symmetrical phthalocyanine complexes with carboxyl groups showed improvements both in fluorescence and triplet quantum yields. All the conjugates except two showed an increase in triplet lifetimes when compared to their respective phthalocyanine complexes. Optical nonlinearities of nine of the phthalocyanine complexes were studied and all the complexes showed characteristic reverse saturable absorption behavior. Complex 10 showed the most promising optical limiting behavior. The aggregation and dissolution studies of the conjugates were also carried out in a simulated biological medium and the silicon level detected was noticed to have increased with incubation time.
- Full Text:
- Date Issued: 2015
- Authors: Fashina, Adedayo
- Date: 2015
- Subjects: Nanoparticles , Phthalocyanines , Zinc , Silica , Photochemistry , Adsorption
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4537 , http://hdl.handle.net/10962/d1017917
- Description: This thesis reports on the synthesis and characterization of both symmetrical and asymmetrical Zinc phthalocyanine complexes. The complexes contained groups such as carboxylic, amino and alkyne for covalent grafting to the surface of silica nanoparticles. The use of symmetrical and asymmetrical complexes was geared towards comparing the non-specific binding of the symmetrical complexes to the specific binding observed in the asymmetrical complexes. The complexes were also doped within the silica matrix and compared to the surface grafted conjugates. The complexes and the conjugates were well characterized with a variety of techniques. The fluorescence lifetimes of the phthalocyanine complexes containing either terminal carboxylic groups or an alkyne group showed a mono-exponential decay while the amino containing phthalocyanine complexes gave a bi-exponential decay. A similar trend was observed for their respective conjugates. Some of the conjugates of the asymmetrical complexes showed a decrease in fluorescence lifetimes and a corresponding decrease in fluorescence quantum yields. The fluorescence quantum yields for all the symmetrical complexes studied showed either an improvement or retained the luminescence of the grafted phthalocyanine complex. Most of the conjugates showed a faster intersystem crossing time in comparison to the complexes alone. The grafted or doped conjugates containing symmetrical phthalocyanine complexes with carboxyl groups showed improvements both in fluorescence and triplet quantum yields. All the conjugates except two showed an increase in triplet lifetimes when compared to their respective phthalocyanine complexes. Optical nonlinearities of nine of the phthalocyanine complexes were studied and all the complexes showed characteristic reverse saturable absorption behavior. Complex 10 showed the most promising optical limiting behavior. The aggregation and dissolution studies of the conjugates were also carried out in a simulated biological medium and the silicon level detected was noticed to have increased with incubation time.
- Full Text:
- Date Issued: 2015
Photophysicochemical properties and in vitro photodynamic therapy activities of zinc phthalocyanine conjugates with biomolecules and single-walled carbon nanotubes
- Authors: Ogbodu, Racheal O
- Date: 2015
- Subjects: Photochemotherapy , Phthalocyanines , Biomolecules
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4544 , http://hdl.handle.net/10962/d1017924
- Description: The synthesis, photophysicochemcial properties, in vitro dark toxicity and photodynamic therapy (PDT) activities of different derivatives of zinc phthalocyanine (ZnPc) conjugates with biomolecules (folic acid, bovine serum albumin (BSA), ascorbic acid, uridine or spermine) and single-walled carbon nanotubes (SWCNTs) are presented in this work. The fluorescence quantum yields (ΦF) (Subscript F) of the ZnPc derivatives or ZnPc-biomolecule conjugates remained relatively the same as compared to the precursor Pcs. Slight increases were observed in the ΦF (Subscript F) values of conjugates containing substituents such as pyrene, folic acid or BSA with intrinsic fluorescence properties. The triplet quantum yield (ΦT ) (Subscript T) values for some ZnPc conjugates increases compared to the precursor ZnPcs due to extended π conjugation (for the conjugate with pyrene) and the presence of phenyl ring that support spin-orbit charge transfer intersystem crossing to triplet state. While some conjugates showed decreases in the ΦT (Subscript T) values compared to precursor ZnPcs due to the presence of substituents that could quench photo-excited state properties. The singlet oxygen quantum yield (ΦΔ ) values follow the trends of the triplet quantum yield values. The conjugates containing BSA also show increases in the ΦΔ values without corresponding increases in ΦT (Subscript T) values due to the ability of BSA to generate free radicals including singlet oxygen. The presence of SWCNTs decreases the photophysicochemcial properties of some ZnPc-SWCNT conjugates compared to the precursor ZnPcs due to photo-induced electron transfer from an excited Pc complex (electron donor) to SWCNTs (electron acceptor). However, increases were observed in some ZnPc-SWCNT conjugates as a result of fast charge recombination process due to highly short-lived radical ion pair produced. These phenomena affected the ΦF (Suscript F) values, ΦT (Suscript T) values, and the ΦΔ values. Increases or decreases in ΦT (Suscript T) values resulted in corresponding increases or decreases in ΦΔ values
- Full Text:
- Date Issued: 2015
- Authors: Ogbodu, Racheal O
- Date: 2015
- Subjects: Photochemotherapy , Phthalocyanines , Biomolecules
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4544 , http://hdl.handle.net/10962/d1017924
- Description: The synthesis, photophysicochemcial properties, in vitro dark toxicity and photodynamic therapy (PDT) activities of different derivatives of zinc phthalocyanine (ZnPc) conjugates with biomolecules (folic acid, bovine serum albumin (BSA), ascorbic acid, uridine or spermine) and single-walled carbon nanotubes (SWCNTs) are presented in this work. The fluorescence quantum yields (ΦF) (Subscript F) of the ZnPc derivatives or ZnPc-biomolecule conjugates remained relatively the same as compared to the precursor Pcs. Slight increases were observed in the ΦF (Subscript F) values of conjugates containing substituents such as pyrene, folic acid or BSA with intrinsic fluorescence properties. The triplet quantum yield (ΦT ) (Subscript T) values for some ZnPc conjugates increases compared to the precursor ZnPcs due to extended π conjugation (for the conjugate with pyrene) and the presence of phenyl ring that support spin-orbit charge transfer intersystem crossing to triplet state. While some conjugates showed decreases in the ΦT (Subscript T) values compared to precursor ZnPcs due to the presence of substituents that could quench photo-excited state properties. The singlet oxygen quantum yield (ΦΔ ) values follow the trends of the triplet quantum yield values. The conjugates containing BSA also show increases in the ΦΔ values without corresponding increases in ΦT (Subscript T) values due to the ability of BSA to generate free radicals including singlet oxygen. The presence of SWCNTs decreases the photophysicochemcial properties of some ZnPc-SWCNT conjugates compared to the precursor ZnPcs due to photo-induced electron transfer from an excited Pc complex (electron donor) to SWCNTs (electron acceptor). However, increases were observed in some ZnPc-SWCNT conjugates as a result of fast charge recombination process due to highly short-lived radical ion pair produced. These phenomena affected the ΦF (Suscript F) values, ΦT (Suscript T) values, and the ΦΔ values. Increases or decreases in ΦT (Suscript T) values resulted in corresponding increases or decreases in ΦΔ values
- Full Text:
- Date Issued: 2015
Phthalocyanine-nanoparticle conjugates for photodynamic therapy of cancer and phototransformation of organic pollutants
- Authors: Khoza, Phindile Brenda
- Date: 2015
- Subjects: Phthalocyanines , Nanoparticles , Photochemotherapy , Cancer -- Chemotherapy , Zinc oxide , Photocatalysis
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4538 , http://hdl.handle.net/10962/d1017918
- Description: The synthesis and extensive spectroscopical characterization of novel phthalocyanines are reported. The new compounds were characterized by elemental analysis, FT-IR, ¹HNMR, mass spectrometry and UV–Vis spectroscopy. The new phthalocyanines showed remarkable photophysicochemical behaviour. The novel phthalocyanines were then conjugated to nanoparticles, silver and ZnO. The coupling of the novel Pcs to nanoparticles was through covalent bonding and ligand exchange. These conjugates were supported onto electrospun polystyrene fibers and chitosan microbeads for use as photocatalysts. The efficiency of the immobilized Pcs and Pc-nanoparticles was assessed by the phototrasfromation of organic pollutants, methyl orange and Rhodamine 6G as model dyes. Upon conjugating phthalocyanines to nanoparticles, there was a great increase in the rate of photodegradation of the model dyes. The photodynamic activity of the novel phthalocyanines upon conjugating to nanoparticles and selected targeting agents is also reported. The targeting agents employed in this study are folic acid and polylysine. Conjugating the phthalocyanines to folic acid or polylysine improved the solubility of the phthalocyanines in aqueous media. The potency of the conjugates was investigated on breast (MCF-7), prostate and melanoma cancer cell lines. The phthalocyanines showed no toxicity in the absence of light. However, upon illumination, a concentration dependent cellular decrease was observed.
- Full Text:
- Date Issued: 2015
- Authors: Khoza, Phindile Brenda
- Date: 2015
- Subjects: Phthalocyanines , Nanoparticles , Photochemotherapy , Cancer -- Chemotherapy , Zinc oxide , Photocatalysis
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4538 , http://hdl.handle.net/10962/d1017918
- Description: The synthesis and extensive spectroscopical characterization of novel phthalocyanines are reported. The new compounds were characterized by elemental analysis, FT-IR, ¹HNMR, mass spectrometry and UV–Vis spectroscopy. The new phthalocyanines showed remarkable photophysicochemical behaviour. The novel phthalocyanines were then conjugated to nanoparticles, silver and ZnO. The coupling of the novel Pcs to nanoparticles was through covalent bonding and ligand exchange. These conjugates were supported onto electrospun polystyrene fibers and chitosan microbeads for use as photocatalysts. The efficiency of the immobilized Pcs and Pc-nanoparticles was assessed by the phototrasfromation of organic pollutants, methyl orange and Rhodamine 6G as model dyes. Upon conjugating phthalocyanines to nanoparticles, there was a great increase in the rate of photodegradation of the model dyes. The photodynamic activity of the novel phthalocyanines upon conjugating to nanoparticles and selected targeting agents is also reported. The targeting agents employed in this study are folic acid and polylysine. Conjugating the phthalocyanines to folic acid or polylysine improved the solubility of the phthalocyanines in aqueous media. The potency of the conjugates was investigated on breast (MCF-7), prostate and melanoma cancer cell lines. The phthalocyanines showed no toxicity in the absence of light. However, upon illumination, a concentration dependent cellular decrease was observed.
- Full Text:
- Date Issued: 2015
Pitied plumage and dying birds : the public mourning of national heroines and post-apartheid foundational mythology construction
- Authors: Kerseboom, Simone
- Date: 2015
- Subjects: Women heroes -- South Africa , Nationalism -- South Africa , Nationalism and collective memory -- South Africa , Post-apartheid era -- South Africa , Women political activists -- South Africa , Dead -- Political aspects -- South Africa , Critical discourse analysis
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:2625 , http://hdl.handle.net/10962/d1019884
- Description: The original contribution of this thesis is the examination of the official construction of a post-apartheid foundation myth through the analysis of the dead body politics of five iconic South African women that spans the three presidencies that have defined South Africa’s democratic era. This thesis examines the death and funeral of Albertina Sisulu, the return and burial of Sara Baartman, and the commemoration of Charlotte Maxeke, Lilian Ngoyi, and Helen Joseph. Sisulu, Baartman, Maxeke, Ngoyi, and Joseph have been constructed as heroines and as foundational figures for the post-apartheid nation in official rhetoric. It will contend that the dead body politics of these women not only informs a new foundational mythology, but also features in the processes of regime legitimation when the ANC-dominated government faces strong societal criticism. Although such official expressions of nationalism may appear exhausted, this thesis will show that nationalism remains a powerful and dangerous force in South Africa that attempts to silence opposition and critical analysis of perceived failing government policies or inaction. This thesis will indicate that as women’s bodies and legacies are appropriated for nationalist projects they are subsumed in discourses of domestic femininity in official rhetoric that dangerously detract from women’s democratic rights and their ability to exercise responsible and productive citizenship in the post-apartheid state. It will argue that women’s historic political activism is contained within the meta-narrative of ‘The Struggle’ and that women are re-subsumed into the patriarchal discourses of the past that are inherited in the present. This thesis approaches this topic by considering a top-to-bottom construction of post-apartheid nationalism through applying feminist critical discourse analysis to official rhetoric articulated at the public mourning and commemorative rituals of these five women.
- Full Text:
- Date Issued: 2015
- Authors: Kerseboom, Simone
- Date: 2015
- Subjects: Women heroes -- South Africa , Nationalism -- South Africa , Nationalism and collective memory -- South Africa , Post-apartheid era -- South Africa , Women political activists -- South Africa , Dead -- Political aspects -- South Africa , Critical discourse analysis
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:2625 , http://hdl.handle.net/10962/d1019884
- Description: The original contribution of this thesis is the examination of the official construction of a post-apartheid foundation myth through the analysis of the dead body politics of five iconic South African women that spans the three presidencies that have defined South Africa’s democratic era. This thesis examines the death and funeral of Albertina Sisulu, the return and burial of Sara Baartman, and the commemoration of Charlotte Maxeke, Lilian Ngoyi, and Helen Joseph. Sisulu, Baartman, Maxeke, Ngoyi, and Joseph have been constructed as heroines and as foundational figures for the post-apartheid nation in official rhetoric. It will contend that the dead body politics of these women not only informs a new foundational mythology, but also features in the processes of regime legitimation when the ANC-dominated government faces strong societal criticism. Although such official expressions of nationalism may appear exhausted, this thesis will show that nationalism remains a powerful and dangerous force in South Africa that attempts to silence opposition and critical analysis of perceived failing government policies or inaction. This thesis will indicate that as women’s bodies and legacies are appropriated for nationalist projects they are subsumed in discourses of domestic femininity in official rhetoric that dangerously detract from women’s democratic rights and their ability to exercise responsible and productive citizenship in the post-apartheid state. It will argue that women’s historic political activism is contained within the meta-narrative of ‘The Struggle’ and that women are re-subsumed into the patriarchal discourses of the past that are inherited in the present. This thesis approaches this topic by considering a top-to-bottom construction of post-apartheid nationalism through applying feminist critical discourse analysis to official rhetoric articulated at the public mourning and commemorative rituals of these five women.
- Full Text:
- Date Issued: 2015
Population estimates and spatial ecology of brown hyaenas in Kwandwe private game reserve
- Authors: Welch, Rebecca Jane
- Date: 2015
- Subjects: Brown hyaena -- Reintroduction -- South Africa , Kwandwe Private Game Reserve
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5932 , http://hdl.handle.net/10962/d1017810
- Description: During the last 25 years, the Eastern Cape Province of South Africa has seen the establishment of many small to medium sized (≤ 440km2) game reserves. These reserves have reintroduced many of the larger indigenous wildlife that had been extirpated by the early 20th century. As such, these reserves and wildlife introductions have created many research opportunities, including investigations on the ecology of reintroduced carnivores in the Thicket biome. Brown hyaenas (Hyaena brunnea) are one of the large carnivore species that have been reintroduced into the area. As these animals have predominantly been studied in more open, arid systems, their reintroduction has provided an excellent opportunity to study the species in an alternate natural habitat. Information gathered from such investigations adds to our knowledge of the species and also provides information for the management of brown hyaenas within small, enclosed reserves. Data were collected over the period of one calendaryear, from February 2013 to February 2014 at Kwandwe Private Game Reserve in the Eastern Cape, South Africa. Brown hyaena population estimates were calculated using capture-recapture methods from individually identifiable images captured during a three month camera trapping survey. Images of brown hyaenas were separated into left- and right-side profiles. Twenty-eight individuals were positively identified from left-side images and 27 from right-side images. Non-spatial and spatially explicit capture-recapture analyses were both run in the program DENSITY 5.0. Density estimates ranged from 14 to 20 individuals/100km2 (equivalent to a total abundance of 26-37 individuals) depending on the method used. Despite the range of estimates, all are considerably higher than in other areaswhere densities have been calculated. Satellite/GPS collars were fitted to three individual brown hyaenas (two males and one female) to measure their home range size and use of space. Home range size was calculated using two different methods, Kernel utilisation distributions and Brownian bridges. Home range estimates were similar using both methods; however Brownian bridge methods appeared to exaggerate the use of space by individuals. Kernel home range sizes for the three individuals ranged between 42.62km2 and 79.88km2. These estimates are considerably smaller than previous findings from other parts of Africa and suggest that sufficient resources may be available within this enclosed system. The results from this study suggest that brown hyaenas are successful generalists in this enclosed system and are able to persist at high densities and occupy relatively small home ranges. This information is important for the managers of small reserves who wish to reintroduce brown hyaenas. Should brown hyaenas be introduced into reserves in the Thicket biome with sufficient resources, the numbers are likely to increase rapidly. If high numbers are not desired then preventative measures (e.g. contraception) should be investigated before release.
- Full Text:
- Date Issued: 2015
- Authors: Welch, Rebecca Jane
- Date: 2015
- Subjects: Brown hyaena -- Reintroduction -- South Africa , Kwandwe Private Game Reserve
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5932 , http://hdl.handle.net/10962/d1017810
- Description: During the last 25 years, the Eastern Cape Province of South Africa has seen the establishment of many small to medium sized (≤ 440km2) game reserves. These reserves have reintroduced many of the larger indigenous wildlife that had been extirpated by the early 20th century. As such, these reserves and wildlife introductions have created many research opportunities, including investigations on the ecology of reintroduced carnivores in the Thicket biome. Brown hyaenas (Hyaena brunnea) are one of the large carnivore species that have been reintroduced into the area. As these animals have predominantly been studied in more open, arid systems, their reintroduction has provided an excellent opportunity to study the species in an alternate natural habitat. Information gathered from such investigations adds to our knowledge of the species and also provides information for the management of brown hyaenas within small, enclosed reserves. Data were collected over the period of one calendaryear, from February 2013 to February 2014 at Kwandwe Private Game Reserve in the Eastern Cape, South Africa. Brown hyaena population estimates were calculated using capture-recapture methods from individually identifiable images captured during a three month camera trapping survey. Images of brown hyaenas were separated into left- and right-side profiles. Twenty-eight individuals were positively identified from left-side images and 27 from right-side images. Non-spatial and spatially explicit capture-recapture analyses were both run in the program DENSITY 5.0. Density estimates ranged from 14 to 20 individuals/100km2 (equivalent to a total abundance of 26-37 individuals) depending on the method used. Despite the range of estimates, all are considerably higher than in other areaswhere densities have been calculated. Satellite/GPS collars were fitted to three individual brown hyaenas (two males and one female) to measure their home range size and use of space. Home range size was calculated using two different methods, Kernel utilisation distributions and Brownian bridges. Home range estimates were similar using both methods; however Brownian bridge methods appeared to exaggerate the use of space by individuals. Kernel home range sizes for the three individuals ranged between 42.62km2 and 79.88km2. These estimates are considerably smaller than previous findings from other parts of Africa and suggest that sufficient resources may be available within this enclosed system. The results from this study suggest that brown hyaenas are successful generalists in this enclosed system and are able to persist at high densities and occupy relatively small home ranges. This information is important for the managers of small reserves who wish to reintroduce brown hyaenas. Should brown hyaenas be introduced into reserves in the Thicket biome with sufficient resources, the numbers are likely to increase rapidly. If high numbers are not desired then preventative measures (e.g. contraception) should be investigated before release.
- Full Text:
- Date Issued: 2015
Post-treatment technologies for integrated algal pond systems
- Authors: Westensee, Dirk Karl
- Date: 2015
- Subjects: Sewage disposal plants -- South Africa -- Grahamstown , Water -- Purification -- Filtration , Water -- Purification -- Slow sand filtration , Sewage -- Purification -- Anaerobic treatment , Sewage -- Purification -- Biological treatment , Algae -- Biotechnology
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5958 , http://hdl.handle.net/10962/d1018180
- Description: Integrated Algae Pond Systems (IAPS) are a derivation of the Oswald designed Algal Integrated Wastewater Pond Systems (AIWPS®) and combine the use of anaerobic and aerobic bioprocesses to effect wastewater treatment. IAPS technology was introduced to South Africa in 1996 and a pilot plant designed and commissioned at the Belmont Valley WWTW in Grahamstown. The system has been in continual use since implementation and affords a secondarily treated water for reclamation according to its design specifications which most closely resemble those of the AIWPS® Advanced Secondary Process developed by Oswald. As a consequence, and as might be expected, while the technology performed well and delivered a final effluent superior to most pond systems deployed in South Africa it was unable to meet The Department of Water Affairs General Standard for nutrient removal and effluent discharge. The work described in this thesis involved the design, construction, and evaluation of several tertiary treatment units (TTU') for incorporation into the IAPS process design. Included were; Maturation Ponds (MP), Slow Sand Filter (SSF) and Rock Filters (RF). Three MP's were constructed in series with a 12 day retention time and operated in parallel with a two-layered SSF and a three-stage RF. Water quality of the effluent emerging from each of these TTU's was monitored over a 10 month period. Significant decreases in the chemical oxygen demand (COD), ammonium-N, phosphate-P, nitrate-N, faecal coliforms (FC) and total coliforms (TC) were achieved by these TTU's. On average, throughout the testing period, water quality was within the statutory limit for discharge to a water course that is not a listed water course, with the exception of the total suspended solids (TSS). The RF was determined as the most suitable TTU for commercial use due to production of a better quality water, smaller footprint, lower construction costs and less maintenance required. From the results of this investigation it is concluded that commercial deployment of IAPS for the treatment of municipal sewage requires the inclusion of a suitable TTU. Furthermore, and based on the findings presented, RF appears most appropriate to ensure that quality of the final effluent meets the standard for discharge.
- Full Text:
- Date Issued: 2015
- Authors: Westensee, Dirk Karl
- Date: 2015
- Subjects: Sewage disposal plants -- South Africa -- Grahamstown , Water -- Purification -- Filtration , Water -- Purification -- Slow sand filtration , Sewage -- Purification -- Anaerobic treatment , Sewage -- Purification -- Biological treatment , Algae -- Biotechnology
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5958 , http://hdl.handle.net/10962/d1018180
- Description: Integrated Algae Pond Systems (IAPS) are a derivation of the Oswald designed Algal Integrated Wastewater Pond Systems (AIWPS®) and combine the use of anaerobic and aerobic bioprocesses to effect wastewater treatment. IAPS technology was introduced to South Africa in 1996 and a pilot plant designed and commissioned at the Belmont Valley WWTW in Grahamstown. The system has been in continual use since implementation and affords a secondarily treated water for reclamation according to its design specifications which most closely resemble those of the AIWPS® Advanced Secondary Process developed by Oswald. As a consequence, and as might be expected, while the technology performed well and delivered a final effluent superior to most pond systems deployed in South Africa it was unable to meet The Department of Water Affairs General Standard for nutrient removal and effluent discharge. The work described in this thesis involved the design, construction, and evaluation of several tertiary treatment units (TTU') for incorporation into the IAPS process design. Included were; Maturation Ponds (MP), Slow Sand Filter (SSF) and Rock Filters (RF). Three MP's were constructed in series with a 12 day retention time and operated in parallel with a two-layered SSF and a three-stage RF. Water quality of the effluent emerging from each of these TTU's was monitored over a 10 month period. Significant decreases in the chemical oxygen demand (COD), ammonium-N, phosphate-P, nitrate-N, faecal coliforms (FC) and total coliforms (TC) were achieved by these TTU's. On average, throughout the testing period, water quality was within the statutory limit for discharge to a water course that is not a listed water course, with the exception of the total suspended solids (TSS). The RF was determined as the most suitable TTU for commercial use due to production of a better quality water, smaller footprint, lower construction costs and less maintenance required. From the results of this investigation it is concluded that commercial deployment of IAPS for the treatment of municipal sewage requires the inclusion of a suitable TTU. Furthermore, and based on the findings presented, RF appears most appropriate to ensure that quality of the final effluent meets the standard for discharge.
- Full Text:
- Date Issued: 2015
Prediction of interacting motifs within the protein subunits of Picornavirus capsids
- Authors: Ross, Caroline Jane
- Date: 2015
- Subjects: Picornaviruses , Antiviral agents , Poliovirus , Coxsackieviruses , Hepatitis A virus , Foot-and-mouth disease virus , Viral proteins
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4151 , http://hdl.handle.net/10962/d1017912
- Description: The Picornaviridae family contains a number of pathogens which are economically important including Poliovirus, Coxsakievirus, Hepatitis A Virus, and Foot-and-Mouth-Disease-Virus. Recently the emergence of novel picornaviruses associated with gastrointestinal, neurological and respiratory diseases in humans has been reported. Although effective vaccines for viruses such as FMDV, PV and HAV have been developed there are currently no antivirals available for the treatment of picornavirus infections. Picornaviruses proteins are classified as: the structural proteins VP1, VP2, VP3 and VP4 which form the subunits of the viral capsid and the replication proteins which function as proteases, RNA-polymerases, primers and membrane binding proteins. Although the host specificity and viral pathogenicity varies across members of the family, the icosahedral capsid is highly conserved. The capsid consists of 60 protomers, each containing a single copy of VP1, VP2 and VP3. A fourth capsid protein, VP4, resides on the internal side of the capsid. Capsid assembly is integral to life-cycle of picornaviruses; however the process is complex and not fully-understood. The overall aim of the study was to broaden the understanding of the evolution and function of the structural proteins across the Picornaviridae family. Firstly a comprehensive analysis of the phylogenetic relationships amongst the individual structural proteins was performed. The functions of the structural proteins were further investigated by an exhaustive motif analysis. A subsequent structural analysis of highly conserved motifs was performed with respect to representative enteroviruses, Foot-and-Mouth-Disease-Virus and Theiler’s Virus. This was supplemented by the in silico prediction of interacting residues within the crystal structures of these protomers. Findings in this study suggest that the capsid proteins may be evolving independently from the replication proteins through possible inter-typic recombination of functional protein regions. Moreover the study predicts that protomer assembly may be facilitated through a network of multiple subunit-subunit interactions. Multiple conserved motifs and principle residues predicted to facilitate capsid subunit-subunit interactions were identified. It was also concluded that motif conservation may support the theory of inter-typic recombination between closely related virus sub-types. As capsid assembly is critical to the viral life-cycle, the principle interacting motifs may serve as novel drug targets for the antiviral treatment of picornavirus infections. Thus the findings in the study may be fundamental to the development of treatments which are more economically feasible or clinically effective than current vaccinations.
- Full Text:
- Date Issued: 2015
- Authors: Ross, Caroline Jane
- Date: 2015
- Subjects: Picornaviruses , Antiviral agents , Poliovirus , Coxsackieviruses , Hepatitis A virus , Foot-and-mouth disease virus , Viral proteins
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4151 , http://hdl.handle.net/10962/d1017912
- Description: The Picornaviridae family contains a number of pathogens which are economically important including Poliovirus, Coxsakievirus, Hepatitis A Virus, and Foot-and-Mouth-Disease-Virus. Recently the emergence of novel picornaviruses associated with gastrointestinal, neurological and respiratory diseases in humans has been reported. Although effective vaccines for viruses such as FMDV, PV and HAV have been developed there are currently no antivirals available for the treatment of picornavirus infections. Picornaviruses proteins are classified as: the structural proteins VP1, VP2, VP3 and VP4 which form the subunits of the viral capsid and the replication proteins which function as proteases, RNA-polymerases, primers and membrane binding proteins. Although the host specificity and viral pathogenicity varies across members of the family, the icosahedral capsid is highly conserved. The capsid consists of 60 protomers, each containing a single copy of VP1, VP2 and VP3. A fourth capsid protein, VP4, resides on the internal side of the capsid. Capsid assembly is integral to life-cycle of picornaviruses; however the process is complex and not fully-understood. The overall aim of the study was to broaden the understanding of the evolution and function of the structural proteins across the Picornaviridae family. Firstly a comprehensive analysis of the phylogenetic relationships amongst the individual structural proteins was performed. The functions of the structural proteins were further investigated by an exhaustive motif analysis. A subsequent structural analysis of highly conserved motifs was performed with respect to representative enteroviruses, Foot-and-Mouth-Disease-Virus and Theiler’s Virus. This was supplemented by the in silico prediction of interacting residues within the crystal structures of these protomers. Findings in this study suggest that the capsid proteins may be evolving independently from the replication proteins through possible inter-typic recombination of functional protein regions. Moreover the study predicts that protomer assembly may be facilitated through a network of multiple subunit-subunit interactions. Multiple conserved motifs and principle residues predicted to facilitate capsid subunit-subunit interactions were identified. It was also concluded that motif conservation may support the theory of inter-typic recombination between closely related virus sub-types. As capsid assembly is critical to the viral life-cycle, the principle interacting motifs may serve as novel drug targets for the antiviral treatment of picornavirus infections. Thus the findings in the study may be fundamental to the development of treatments which are more economically feasible or clinically effective than current vaccinations.
- Full Text:
- Date Issued: 2015
Primary maths teacher learning and identity within a numeracy in-service community of practice
- Authors: Pausigere, Peter
- Date: 2015
- Subjects: Mathematics -- Study and teaching (Elementary) -- South Africa , Teachers -- In-service training -- South Africa , Student-centered learning -- South Africa , Communities of practice -- South Africa , Educational change -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:2019 , http://hdl.handle.net/10962/d1017183
- Description: This study focuses on the processes of primary maths teacher learning and how their identities and practices evolve in relation to participation in a primary maths focused in-service teacher education programme, called the Numeracy Inquiry Community of Leader Educators (NICLE).Additionally it investigates activities, relations and forms of participation within the Community of Practice (CoP) which enable or constrain evolving primary maths identities and practices and how these relate to the broader context. The study draws from the situative-participationists (Lave, 1996; Wenger, 1998; Sfard & Prusak, 2005; Wenger et al, 2002) theoretical framework supplemented by Bernstein’s (2000) pedagogic identity model. Using a qualitative educational interpretive approach I sampled 8 primary teachers drawn from NICLE and gathered data through participant observations, interactive interviews, document analysis and reflective journals. Analysing the key data themes that emerged from teacher learning stories, which I have called stelos, the study explains the nature of the primary maths teachers’ learning, transformation and participation experiences in NICLE using the synonyms reinvigoration and remediation and activation and relating these semantics to the teachers’ mathematical identities and histories. The study also explains the processes through which primary maths teacher identities evolve in relation to participation in an in-service CoP as ‘insiding’ and ‘outcropping’. Interpreting qualitative data from the empirical field indicates that teachers participating in NICLE mostly took-up into their maths classrooms key numeracy-domain concepts, resources and issues presented by primary maths experts which are informed by research and theory that link to practices. Teachers collaboratively and actively engaged in a range of activities that relate to classroom practices. Teacher learning was also enabled when teachers engaged in maths overlapping communities of practice, shared classroom experiences in friendly ways with fellow NICLE teachers and engaged with NICLE presenters who mutually respected and regarded them as professionals. Such affordances were said to enable teachers to engage learners in maths classes and improve their understanding of specific primary maths concepts. On the other hand teachers felt challenged by the travelling distance, limited time and also raised the tension of how to scale-up maths professional development initiatives to include schools from their community. The study makes a theoretical contribution by illustrating how Bernstein’s pedagogic identity model and its elaboration by Tyler (1999) provides analytical tools to interrogate macro educational changes and connect these to the micro processes and teacher identities.
- Full Text:
- Date Issued: 2015
- Authors: Pausigere, Peter
- Date: 2015
- Subjects: Mathematics -- Study and teaching (Elementary) -- South Africa , Teachers -- In-service training -- South Africa , Student-centered learning -- South Africa , Communities of practice -- South Africa , Educational change -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:2019 , http://hdl.handle.net/10962/d1017183
- Description: This study focuses on the processes of primary maths teacher learning and how their identities and practices evolve in relation to participation in a primary maths focused in-service teacher education programme, called the Numeracy Inquiry Community of Leader Educators (NICLE).Additionally it investigates activities, relations and forms of participation within the Community of Practice (CoP) which enable or constrain evolving primary maths identities and practices and how these relate to the broader context. The study draws from the situative-participationists (Lave, 1996; Wenger, 1998; Sfard & Prusak, 2005; Wenger et al, 2002) theoretical framework supplemented by Bernstein’s (2000) pedagogic identity model. Using a qualitative educational interpretive approach I sampled 8 primary teachers drawn from NICLE and gathered data through participant observations, interactive interviews, document analysis and reflective journals. Analysing the key data themes that emerged from teacher learning stories, which I have called stelos, the study explains the nature of the primary maths teachers’ learning, transformation and participation experiences in NICLE using the synonyms reinvigoration and remediation and activation and relating these semantics to the teachers’ mathematical identities and histories. The study also explains the processes through which primary maths teacher identities evolve in relation to participation in an in-service CoP as ‘insiding’ and ‘outcropping’. Interpreting qualitative data from the empirical field indicates that teachers participating in NICLE mostly took-up into their maths classrooms key numeracy-domain concepts, resources and issues presented by primary maths experts which are informed by research and theory that link to practices. Teachers collaboratively and actively engaged in a range of activities that relate to classroom practices. Teacher learning was also enabled when teachers engaged in maths overlapping communities of practice, shared classroom experiences in friendly ways with fellow NICLE teachers and engaged with NICLE presenters who mutually respected and regarded them as professionals. Such affordances were said to enable teachers to engage learners in maths classes and improve their understanding of specific primary maths concepts. On the other hand teachers felt challenged by the travelling distance, limited time and also raised the tension of how to scale-up maths professional development initiatives to include schools from their community. The study makes a theoretical contribution by illustrating how Bernstein’s pedagogic identity model and its elaboration by Tyler (1999) provides analytical tools to interrogate macro educational changes and connect these to the micro processes and teacher identities.
- Full Text:
- Date Issued: 2015
Pro-active visualization of cyber security on a National Level : a South African case study
- Authors: Swart, Ignatius Petrus
- Date: 2015
- Subjects: Internet -- Security measures -- South Africa , Computer security -- Government policy -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4718 , http://hdl.handle.net/10962/d1017940
- Description: The need for increased national cyber security situational awareness is evident from the growing number of published national cyber security strategies. Governments are progressively seen as responsible for cyber security, but at the same time increasingly constrained by legal, privacy and resource considerations. Infrastructure and services that form part of the national cyber domain are often not under the control of government, necessitating the need for information sharing between governments and commercial partners. While sharing of security information is necessary, it typically requires considerable time to be implemented effectively. In an effort to decrease the time and effort required for cyber security situational awareness, this study considered commercially available data sources relating to a national cyber domain. Open source information is typically used by attackers to gather information with great success. An understanding of the data provided by these sources can also afford decision makers the opportunity to set priorities more effectively. Through the use of an adapted Joint Directors of Laboratories (JDL) fusion model, an experimental system was implemented that visualized the potential that open source intelligence could have on cyber situational awareness. Datasets used in the validation of the model contained information obtained from eight different data sources over a two year period with a focus on the South African .co.za sub domain. Over a million infrastructure devices were examined in this study along with information pertaining to a potential 88 million vulnerabilities on these devices. During the examination of data sources, a severe lack of information regarding the human aspect in cyber security was identified that led to the creation of a novel Personally Identifiable Information detection sensor (PII). The resultant two million records pertaining to PII in the South African domain were incorporated into the data fusion experiment for processing. The results of this processing are discussed in the three case studies. The results offered in this study aim to highlight how data fusion and effective visualization can serve to move national cyber security from a primarily reactive undertaking to a more pro-active model.
- Full Text:
- Date Issued: 2015
- Authors: Swart, Ignatius Petrus
- Date: 2015
- Subjects: Internet -- Security measures -- South Africa , Computer security -- Government policy -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4718 , http://hdl.handle.net/10962/d1017940
- Description: The need for increased national cyber security situational awareness is evident from the growing number of published national cyber security strategies. Governments are progressively seen as responsible for cyber security, but at the same time increasingly constrained by legal, privacy and resource considerations. Infrastructure and services that form part of the national cyber domain are often not under the control of government, necessitating the need for information sharing between governments and commercial partners. While sharing of security information is necessary, it typically requires considerable time to be implemented effectively. In an effort to decrease the time and effort required for cyber security situational awareness, this study considered commercially available data sources relating to a national cyber domain. Open source information is typically used by attackers to gather information with great success. An understanding of the data provided by these sources can also afford decision makers the opportunity to set priorities more effectively. Through the use of an adapted Joint Directors of Laboratories (JDL) fusion model, an experimental system was implemented that visualized the potential that open source intelligence could have on cyber situational awareness. Datasets used in the validation of the model contained information obtained from eight different data sources over a two year period with a focus on the South African .co.za sub domain. Over a million infrastructure devices were examined in this study along with information pertaining to a potential 88 million vulnerabilities on these devices. During the examination of data sources, a severe lack of information regarding the human aspect in cyber security was identified that led to the creation of a novel Personally Identifiable Information detection sensor (PII). The resultant two million records pertaining to PII in the South African domain were incorporated into the data fusion experiment for processing. The results of this processing are discussed in the three case studies. The results offered in this study aim to highlight how data fusion and effective visualization can serve to move national cyber security from a primarily reactive undertaking to a more pro-active model.
- Full Text:
- Date Issued: 2015
Production of Cydia pomonella granulovirus (CpGV) in a heteralogous host, Thaumatotibia Leucotreta (Meyrick) (False codling moth)
- Authors: Chambers, Craig Brian
- Date: 2015
- Subjects: Cryptophlebia leucotreta -- South Africa , Codling moth -- South Africa , Apples -- Diseases and pests -- South Africa , Codling moth -- Biological control -- South Africa , Insect pests -- Biological control -- South Africa , Biological pest control agents -- South Africa , Baculoviruses -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5935 , http://hdl.handle.net/10962/d1017906
- Description: Cydia pomonella (Linnaeus) (Family: Tortricidae), the codling moth, is considered one of the most significant pests of apples and pears worldwide, causing up to 80% crop loss in orchards if no control measures are applied. Cydia pomonella is oligophagous feeding on a number of alternate hosts including quince, walnuts, apricots, peaches, plums and nectarines. Historically the control of this pest has been achieved with the use of various chemical control strategies which have maintained pest levels below the economic threshold at a relatively low cost to the grower. However, there are serious concerns surrounding the use of chemical insecticides including the development of resistance in insect populations, the banning of various insecticides, regulations for lowering of the maximum residue level and employee and consumer safety. For this reason, alternate measures of control are slowly being adopted by growers such as mating disruption, cultural methods and the use of baculovirus biopesticides as part of integrated pest management programmes. The reluctance of growers to accept baculovirus or other biological control products in the past has been due to questionable product quality and inconsistencies in their field performance. Moreover, the development and application of biological control products is more costly than the use of chemical alternatives. Baculoviruses are arthropod specific viruses that are highly virulent to a number of lepidopteran species. Due to the virulence and host specificity of baculoviruses, Cydia pomonella granulovirus has been extensively and successfully used as part of integrated pest management systems for the control of C. pomonella in Europe and around the world, including South Africa. Commercial formulations have been typically based on the Mexican strain of CpGV. However due to long-term multiple applications of CpGV and the reliance on CpGV in organic farming practices in Europe, resistance to the CpGV-M strain has developed in a number of field populations of C. pomonella. This study aimed to identify and characterize novel isolates of CpGV in South Africa and compare their virulence with the commercial standard CpGV-M. Secondly, since C. pomonella is difficult to culture on a large scale, an alternate method of CpGV production was investigated in order to determine if CpGV could be produced more efficiently and at a reduced cost without negatively impacting the quality of the product. Several isolates of CpGV were recovered either from field collected larvae or from a laboratory-reared C. pomonella colony. Characterisation of DNA profiles using a variety of restriction enzymes revealed that only a single isolate, CpGV-SA, was genetically different from the Mexican strain of the virus used in the commercially available CpGV based products in South Africa. In dose-response bioassays using CpGV-SA, LC₅₀ and LC₉₀ values for neonate C. pomonella larvae were 3.18 x 10³ OBs/ml and 7.33 x 10⁴ respectively. A comparison of these values with those of CpGV-M indicated no significant difference in the virulence of the two isolates under laboratory conditions. This is a first report of a genetically distinct CpGV isolate in South Africa. The biological activity and novelty of CpGV-SA makes this isolate a potentially important tool for CpGV resistance management in South Africa. In order to justify production of CpGV in an alternative host, studies on the comparative biological performance of C. pomonella and T. leucotreta based on oviposition, time to hatch, larval developmental times and rearing efficiency as well as production costs were performed. Thaumatotibia leucotreta was found to be more fecund and to have significantly shorter egg and larval developmental times. In addition, larval production per unit of artificial diet was significantly higher than for C. pomonella. This resulted in T. leucotreta being more cost effective to produce with implications for reduced insectary space, sanitation practices as well as the labour component of production. Virus yield data generated by inoculation both C. pomonella and T. leucotreta with nine concentrations of CpGV resulted in comparable virus yields, justifying the continuation of the research into production of CpGV in T. leucotreta. It was important to determine the LC and LT values required for mass production of CpGV in late instar T. leucotreta larvae. Dose- and time-response bioassays with CpGV-M were conducted on artificial diet to determine these values. Fourth instar LC₅₀ and LC₉₀ values were 5.96 x 10³ OBs/ml and 1.64 x 10⁵ OBs/ml respectively. LT50 and LT90 values were 81.10 hours and 88.58 hours respectively. Fifth instar LC₅₀ and LC₉₀ values were 6.88 x 10⁴ OBs/ml and 9.78 x 10⁶ OBs/ml respectively. LT₅₀ and LT₉₀ values were 111.56 hours and 137.57 hours respectively. Virus produced in fourth instar T. leucotreta larvae was bioassayed against C. pomonella neonate larvae and compared to CpGV-M to establish if production in the heterologous host negatively affected the virulence of the isolate. No significant difference in virulence was observed between virus produced in T. leucotreta and that produced in C. pomonella. The data generated in the bioassays was used in CpGV mass production trials to evaluate production. All production methods tested produced acceptable virus yields. To examine the quality of the virus product, genomic DNA was extracted from larval cadavers and subjected to REN analysis with HindIII. The resulting DNA profiles indicated that the virus product was contaminated with the homologous virus, CrleGV. Based on the above results, the use of T. leucotreta as an alternate host for the in vivo production of CpGV on a commercial basis is not at this stage viable and requires further investigation before this production methodology can be reliable used to produce CpGV. However, this study has shown that CpGV can be produced in a homologous host, T. leucotreta and significant strides have been made towards developing a set of quality control standards that are essential for further development of successful production methodology. Finally a novel isolate of CpGV has been identified with comparable virulence to the CpGV-M. This is an important finding as it has broad reaching implications for resistance management of CpGV products in South Africa.
- Full Text:
- Date Issued: 2015
- Authors: Chambers, Craig Brian
- Date: 2015
- Subjects: Cryptophlebia leucotreta -- South Africa , Codling moth -- South Africa , Apples -- Diseases and pests -- South Africa , Codling moth -- Biological control -- South Africa , Insect pests -- Biological control -- South Africa , Biological pest control agents -- South Africa , Baculoviruses -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5935 , http://hdl.handle.net/10962/d1017906
- Description: Cydia pomonella (Linnaeus) (Family: Tortricidae), the codling moth, is considered one of the most significant pests of apples and pears worldwide, causing up to 80% crop loss in orchards if no control measures are applied. Cydia pomonella is oligophagous feeding on a number of alternate hosts including quince, walnuts, apricots, peaches, plums and nectarines. Historically the control of this pest has been achieved with the use of various chemical control strategies which have maintained pest levels below the economic threshold at a relatively low cost to the grower. However, there are serious concerns surrounding the use of chemical insecticides including the development of resistance in insect populations, the banning of various insecticides, regulations for lowering of the maximum residue level and employee and consumer safety. For this reason, alternate measures of control are slowly being adopted by growers such as mating disruption, cultural methods and the use of baculovirus biopesticides as part of integrated pest management programmes. The reluctance of growers to accept baculovirus or other biological control products in the past has been due to questionable product quality and inconsistencies in their field performance. Moreover, the development and application of biological control products is more costly than the use of chemical alternatives. Baculoviruses are arthropod specific viruses that are highly virulent to a number of lepidopteran species. Due to the virulence and host specificity of baculoviruses, Cydia pomonella granulovirus has been extensively and successfully used as part of integrated pest management systems for the control of C. pomonella in Europe and around the world, including South Africa. Commercial formulations have been typically based on the Mexican strain of CpGV. However due to long-term multiple applications of CpGV and the reliance on CpGV in organic farming practices in Europe, resistance to the CpGV-M strain has developed in a number of field populations of C. pomonella. This study aimed to identify and characterize novel isolates of CpGV in South Africa and compare their virulence with the commercial standard CpGV-M. Secondly, since C. pomonella is difficult to culture on a large scale, an alternate method of CpGV production was investigated in order to determine if CpGV could be produced more efficiently and at a reduced cost without negatively impacting the quality of the product. Several isolates of CpGV were recovered either from field collected larvae or from a laboratory-reared C. pomonella colony. Characterisation of DNA profiles using a variety of restriction enzymes revealed that only a single isolate, CpGV-SA, was genetically different from the Mexican strain of the virus used in the commercially available CpGV based products in South Africa. In dose-response bioassays using CpGV-SA, LC₅₀ and LC₉₀ values for neonate C. pomonella larvae were 3.18 x 10³ OBs/ml and 7.33 x 10⁴ respectively. A comparison of these values with those of CpGV-M indicated no significant difference in the virulence of the two isolates under laboratory conditions. This is a first report of a genetically distinct CpGV isolate in South Africa. The biological activity and novelty of CpGV-SA makes this isolate a potentially important tool for CpGV resistance management in South Africa. In order to justify production of CpGV in an alternative host, studies on the comparative biological performance of C. pomonella and T. leucotreta based on oviposition, time to hatch, larval developmental times and rearing efficiency as well as production costs were performed. Thaumatotibia leucotreta was found to be more fecund and to have significantly shorter egg and larval developmental times. In addition, larval production per unit of artificial diet was significantly higher than for C. pomonella. This resulted in T. leucotreta being more cost effective to produce with implications for reduced insectary space, sanitation practices as well as the labour component of production. Virus yield data generated by inoculation both C. pomonella and T. leucotreta with nine concentrations of CpGV resulted in comparable virus yields, justifying the continuation of the research into production of CpGV in T. leucotreta. It was important to determine the LC and LT values required for mass production of CpGV in late instar T. leucotreta larvae. Dose- and time-response bioassays with CpGV-M were conducted on artificial diet to determine these values. Fourth instar LC₅₀ and LC₉₀ values were 5.96 x 10³ OBs/ml and 1.64 x 10⁵ OBs/ml respectively. LT50 and LT90 values were 81.10 hours and 88.58 hours respectively. Fifth instar LC₅₀ and LC₉₀ values were 6.88 x 10⁴ OBs/ml and 9.78 x 10⁶ OBs/ml respectively. LT₅₀ and LT₉₀ values were 111.56 hours and 137.57 hours respectively. Virus produced in fourth instar T. leucotreta larvae was bioassayed against C. pomonella neonate larvae and compared to CpGV-M to establish if production in the heterologous host negatively affected the virulence of the isolate. No significant difference in virulence was observed between virus produced in T. leucotreta and that produced in C. pomonella. The data generated in the bioassays was used in CpGV mass production trials to evaluate production. All production methods tested produced acceptable virus yields. To examine the quality of the virus product, genomic DNA was extracted from larval cadavers and subjected to REN analysis with HindIII. The resulting DNA profiles indicated that the virus product was contaminated with the homologous virus, CrleGV. Based on the above results, the use of T. leucotreta as an alternate host for the in vivo production of CpGV on a commercial basis is not at this stage viable and requires further investigation before this production methodology can be reliable used to produce CpGV. However, this study has shown that CpGV can be produced in a homologous host, T. leucotreta and significant strides have been made towards developing a set of quality control standards that are essential for further development of successful production methodology. Finally a novel isolate of CpGV has been identified with comparable virulence to the CpGV-M. This is an important finding as it has broad reaching implications for resistance management of CpGV products in South Africa.
- Full Text:
- Date Issued: 2015
Professional development among counselling psychology interns : exploring critical incidents
- Authors: Teixeira, Beverley
- Date: 2015
- Subjects: Counseling psychologists -- Training of -- South Africa , Critical incident technique , Career development -- South Africa , Internship programs -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3265 , http://hdl.handle.net/10962/d1017888
- Description: The journey towards becoming a counselling psychologist, in South Africa, includes the completion a 12 month internship. The internship year holds many challenges and demands for novice professionals and aims to assist them in making the transition from student to professional. This study aims to explore the subjective experiences of intern counselling psychologists and the critical incidents which assist them in making this transition. In addition, it aims to identify experiences impacting on the interns’ professional development and professional identity. Three registered counselling psychologists, who completed their internship at a South African university counselling centre within the last year, were recruited and participated in individual interviews. These interviews were semi-structured and followed the Critical Incident Technique method. Each interview was voice recorded and transcribed. The data collected was analysed using thematic content analysis. As the research design is qualitative, using a phenomenological approach, the focus is on presenting information-rich and detailed descriptions of participants “lived” experiences of their internship year. It attempts to understand significant incidents or events which influenced the participants’ professional and personal development as they navigate through this ambiguous period to become independent and ethical practitioners. Four predominant themes emerged from the data collected, which include a discussion pertaining to professional boundaries and limitations, learning within the internship environment, the effects of professional and personal support and, lastly, the transition from dependent to independent professional functioning.
- Full Text:
- Date Issued: 2015
- Authors: Teixeira, Beverley
- Date: 2015
- Subjects: Counseling psychologists -- Training of -- South Africa , Critical incident technique , Career development -- South Africa , Internship programs -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3265 , http://hdl.handle.net/10962/d1017888
- Description: The journey towards becoming a counselling psychologist, in South Africa, includes the completion a 12 month internship. The internship year holds many challenges and demands for novice professionals and aims to assist them in making the transition from student to professional. This study aims to explore the subjective experiences of intern counselling psychologists and the critical incidents which assist them in making this transition. In addition, it aims to identify experiences impacting on the interns’ professional development and professional identity. Three registered counselling psychologists, who completed their internship at a South African university counselling centre within the last year, were recruited and participated in individual interviews. These interviews were semi-structured and followed the Critical Incident Technique method. Each interview was voice recorded and transcribed. The data collected was analysed using thematic content analysis. As the research design is qualitative, using a phenomenological approach, the focus is on presenting information-rich and detailed descriptions of participants “lived” experiences of their internship year. It attempts to understand significant incidents or events which influenced the participants’ professional and personal development as they navigate through this ambiguous period to become independent and ethical practitioners. Four predominant themes emerged from the data collected, which include a discussion pertaining to professional boundaries and limitations, learning within the internship environment, the effects of professional and personal support and, lastly, the transition from dependent to independent professional functioning.
- Full Text:
- Date Issued: 2015
Properties of traveling ionospheric disturbances (TIDs) over the Western Cape, South Africa
- Authors: Tyalimpi, Vumile Mike
- Date: 2015
- Subjects: Doppler radar , Geographic information systems , Traveling ionospheric disturbances -- south Africa , Ionospheric disturbances -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5557 , http://hdl.handle.net/10962/d1017901
- Description: Travelling Ionospheric Disturbances (TIDs) are said to be produced by atmospheric gravitational waves propagating through the neutral ionosphere. These are smaller in amplitude and period when compared to most ionospheric disturbances and hence more difficult to measure. Very little is known about the properties of the travelling ionospheric disturbances (TIDs) over the Southern Hemisphere regions since studies have been conducted mostly over the Northern Hemisphere regions. This study presents a framework, using a High Frequency (HF) Doppler radar to investigate the physical properties and the possible driving mechanisms of TIDs. This research focuses on studying the characteristics of the TIDs, such as period, velocity and temporal variations, using HF Doppler measurements taken in South Africa. By making use of a Wavelet Analysis technique, the TIDs’ characteristics were determined. A statistical summary on speed and direction of propagation of the observed TIDs was performed. The winter medium scale travelling ionospheric disturbances (MSTIDs) observed are generally faster than the summer MSTIDs. For all seasons, the MSTIDs had a preferred south-southwest direction of propagation. Most of the large scale travelling ionospheric disturbances (LSTIDs) were observed during the night and of these, the spring LSTIDs were fastest when compared to autumn and summer LSTIDs. The general direction of travel of the observed LSTIDs is south-southeast. Total Electron Content (TEC), derived from Global Positioning System (GPS) measurements, were used to validate some of the TID results obtained from the HF Doppler data. The Horizontal Wind Model (HWM07), magnetic K index, and solar terminators were used to determine the possible sources of the observed TIDs. Only 41% of the observed TIDs were successfully linked to their possible sources of excitation. The information gathered from this study will be valuable in future radio communications and will serve as means to improve the existing ionospheric models over the South African region.
- Full Text:
- Date Issued: 2015
- Authors: Tyalimpi, Vumile Mike
- Date: 2015
- Subjects: Doppler radar , Geographic information systems , Traveling ionospheric disturbances -- south Africa , Ionospheric disturbances -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5557 , http://hdl.handle.net/10962/d1017901
- Description: Travelling Ionospheric Disturbances (TIDs) are said to be produced by atmospheric gravitational waves propagating through the neutral ionosphere. These are smaller in amplitude and period when compared to most ionospheric disturbances and hence more difficult to measure. Very little is known about the properties of the travelling ionospheric disturbances (TIDs) over the Southern Hemisphere regions since studies have been conducted mostly over the Northern Hemisphere regions. This study presents a framework, using a High Frequency (HF) Doppler radar to investigate the physical properties and the possible driving mechanisms of TIDs. This research focuses on studying the characteristics of the TIDs, such as period, velocity and temporal variations, using HF Doppler measurements taken in South Africa. By making use of a Wavelet Analysis technique, the TIDs’ characteristics were determined. A statistical summary on speed and direction of propagation of the observed TIDs was performed. The winter medium scale travelling ionospheric disturbances (MSTIDs) observed are generally faster than the summer MSTIDs. For all seasons, the MSTIDs had a preferred south-southwest direction of propagation. Most of the large scale travelling ionospheric disturbances (LSTIDs) were observed during the night and of these, the spring LSTIDs were fastest when compared to autumn and summer LSTIDs. The general direction of travel of the observed LSTIDs is south-southeast. Total Electron Content (TEC), derived from Global Positioning System (GPS) measurements, were used to validate some of the TID results obtained from the HF Doppler data. The Horizontal Wind Model (HWM07), magnetic K index, and solar terminators were used to determine the possible sources of the observed TIDs. Only 41% of the observed TIDs were successfully linked to their possible sources of excitation. The information gathered from this study will be valuable in future radio communications and will serve as means to improve the existing ionospheric models over the South African region.
- Full Text:
- Date Issued: 2015
Pseudo-random access compressed archive for security log data
- Authors: Radley, Johannes Jurgens
- Date: 2015
- Subjects: Computer security , Information storage and retrieval systems , Data compression (Computer science)
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4723 , http://hdl.handle.net/10962/d1020019
- Description: We are surrounded by an increasing number of devices and applications that produce a huge quantity of machine generated data. Almost all the machine data contains some element of security information that can be used to discover, monitor and investigate security events.The work proposes a pseudo-random access compressed storage method for log data to be used with an information retrieval system that in turn provides the ability to search and correlate log data and the corresponding events. We explain the method for converting log files into distinct events and storing the events in a compressed file. This yields an entry identifier for each log entry that provides a pointer that can be used by indexing methods. The research also evaluates the compression performance penalties encountered by using this storage system, including decreased compression ratio, as well as increased compression and decompression times.
- Full Text:
- Date Issued: 2015
- Authors: Radley, Johannes Jurgens
- Date: 2015
- Subjects: Computer security , Information storage and retrieval systems , Data compression (Computer science)
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4723 , http://hdl.handle.net/10962/d1020019
- Description: We are surrounded by an increasing number of devices and applications that produce a huge quantity of machine generated data. Almost all the machine data contains some element of security information that can be used to discover, monitor and investigate security events.The work proposes a pseudo-random access compressed storage method for log data to be used with an information retrieval system that in turn provides the ability to search and correlate log data and the corresponding events. We explain the method for converting log files into distinct events and storing the events in a compressed file. This yields an entry identifier for each log entry that provides a pointer that can be used by indexing methods. The research also evaluates the compression performance penalties encountered by using this storage system, including decreased compression ratio, as well as increased compression and decompression times.
- Full Text:
- Date Issued: 2015
Public understanding of malaria in pregnancy : selected Dar es Salaam audiences' reception of the health education film Chumo
- Authors: Nkwera, Godfrey
- Date: 2015
- Subjects: Chumo (Television program) , Malaria in pregnancy -- Tanzania -- Dar es Salaam , Health education -- Tanzania -- Dar es Salaam , Communication in medicine -- Tanzania -- Dar es Salaam , Sex role -- Tanzania -- Dar es Salaam , Health behavior -- Tanzania -- Dar es Salaam , Health behavior -- Sex differences -- Tanzania -- Dar es Salaam
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3544 , http://hdl.handle.net/10962/d1017785
- Description: This study examines the impact of a health education film, Chumo, in Dar es Salaam on knowledge about malaria in pregnancy. Specifically, the study examines the meanings that the selected audiences make after watching the film. Drawing on the tradition of ‘reception studies’, the data for this study was generated through focus group discussions. These discussions were preceded by thematic analysis of the film and its script. An analysis of the audiences’ responses reveals that Chumo, mostly, successfully conveyed new knowledge about malaria in pregnancy, and reinforced existing knowledge bases about the disease. The audiences were able to ‘decipher’ most of the preferred meanings (of the producers) with regard to the disease, particularly in relation to the transmission of the disease and its prevention in pregnant woman. For example, the analysis indicates that both women and men become more aware of the importance of attending antenatal care sessions at local clinics (hereafter ANC). An interesting finding is that men, mostly, expressed a reluctance to attend ANC with their wives because they fear having to undergo HIV/AIDS testing. Men also expressed the sentiment that attending ANC is a women’s responsibility. The discussion groups also raised issues about the use of insecticide-treated nets - some people believe that using them will affect their health because of the chemicals used to treat the nets. From the reception analysis, various other meanings and themes, relating to the choice of storylines and gender stereotypes used in the story, were raised in discussion. The study attempted to assess whether the storyline was advantageous in conveying the core educational messages, or if some elements of the storyline either ‘got in the way’ or reinforced gender roles in ways that may or may not be helpful in terms of combatting malaria in pregnancy. The study also found that Chumo stimulated interpersonal communication, which may trigger behaviour change. It can be demonstrated, at least for the participants in these focus groups, that the film motivated positive attitudes towards behaviour change, i.e. created at least some intention to change. However, interpersonal communication and attitude to change are not, of course, actual change of behaviour: these elements only indicate the possibility of behaviour change in the future. Further study needs to be undertaken to explore whether the actual change took place and whether the change is a result of the exposure to Chumo.
- Full Text:
- Date Issued: 2015
- Authors: Nkwera, Godfrey
- Date: 2015
- Subjects: Chumo (Television program) , Malaria in pregnancy -- Tanzania -- Dar es Salaam , Health education -- Tanzania -- Dar es Salaam , Communication in medicine -- Tanzania -- Dar es Salaam , Sex role -- Tanzania -- Dar es Salaam , Health behavior -- Tanzania -- Dar es Salaam , Health behavior -- Sex differences -- Tanzania -- Dar es Salaam
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3544 , http://hdl.handle.net/10962/d1017785
- Description: This study examines the impact of a health education film, Chumo, in Dar es Salaam on knowledge about malaria in pregnancy. Specifically, the study examines the meanings that the selected audiences make after watching the film. Drawing on the tradition of ‘reception studies’, the data for this study was generated through focus group discussions. These discussions were preceded by thematic analysis of the film and its script. An analysis of the audiences’ responses reveals that Chumo, mostly, successfully conveyed new knowledge about malaria in pregnancy, and reinforced existing knowledge bases about the disease. The audiences were able to ‘decipher’ most of the preferred meanings (of the producers) with regard to the disease, particularly in relation to the transmission of the disease and its prevention in pregnant woman. For example, the analysis indicates that both women and men become more aware of the importance of attending antenatal care sessions at local clinics (hereafter ANC). An interesting finding is that men, mostly, expressed a reluctance to attend ANC with their wives because they fear having to undergo HIV/AIDS testing. Men also expressed the sentiment that attending ANC is a women’s responsibility. The discussion groups also raised issues about the use of insecticide-treated nets - some people believe that using them will affect their health because of the chemicals used to treat the nets. From the reception analysis, various other meanings and themes, relating to the choice of storylines and gender stereotypes used in the story, were raised in discussion. The study attempted to assess whether the storyline was advantageous in conveying the core educational messages, or if some elements of the storyline either ‘got in the way’ or reinforced gender roles in ways that may or may not be helpful in terms of combatting malaria in pregnancy. The study also found that Chumo stimulated interpersonal communication, which may trigger behaviour change. It can be demonstrated, at least for the participants in these focus groups, that the film motivated positive attitudes towards behaviour change, i.e. created at least some intention to change. However, interpersonal communication and attitude to change are not, of course, actual change of behaviour: these elements only indicate the possibility of behaviour change in the future. Further study needs to be undertaken to explore whether the actual change took place and whether the change is a result of the exposure to Chumo.
- Full Text:
- Date Issued: 2015
PyMORESANE: A Pythonic and CUDA-accelerated implementation of the MORESANE deconvolution algorithm
- Authors: Kenyon, Jonathan
- Date: 2015
- Subjects: Radio astronomy , Imaging systems in astronomy , MOdel REconstruction by Synthesis-ANalysis Estimators (MORESANE)
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5563 , http://hdl.handle.net/10962/d1020098
- Description: The inadequacies of the current generation of deconvolution algorithms are rapidly becoming apparent as new, more sensitive radio interferometers are constructed. In light of these inadequacies, there is renewed interest in the field of deconvolution. Many new algorithms are being developed using the mathematical framework of compressed sensing. One such technique, MORESANE, has recently been shown to be a powerful tool for the recovery of faint difuse emission from synthetic and simulated data. However, the original implementation is not well-suited to large problem sizes due to its computational complexity. Additionally, its use of proprietary software prevents it from being freely distributed and used. This has motivated the development of a freely available Python implementation, PyMORESANE. This thesis describes the implementation of PyMORESANE as well as its subsequent augmentation with MPU and GPGPU code. These additions accelerate the algorithm and thus make it competitive with its legacy counterparts. The acceleration of the algorithm is verified by means of benchmarking tests for varying image size and complexity. Additionally, PyMORESANE is shown to work not only on synthetic data, but on real observational data. This verification means that the MORESANE algorithm, and consequently the PyMORESANE implementation, can be added to the current arsenal of deconvolution tools.
- Full Text:
- Date Issued: 2015
- Authors: Kenyon, Jonathan
- Date: 2015
- Subjects: Radio astronomy , Imaging systems in astronomy , MOdel REconstruction by Synthesis-ANalysis Estimators (MORESANE)
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5563 , http://hdl.handle.net/10962/d1020098
- Description: The inadequacies of the current generation of deconvolution algorithms are rapidly becoming apparent as new, more sensitive radio interferometers are constructed. In light of these inadequacies, there is renewed interest in the field of deconvolution. Many new algorithms are being developed using the mathematical framework of compressed sensing. One such technique, MORESANE, has recently been shown to be a powerful tool for the recovery of faint difuse emission from synthetic and simulated data. However, the original implementation is not well-suited to large problem sizes due to its computational complexity. Additionally, its use of proprietary software prevents it from being freely distributed and used. This has motivated the development of a freely available Python implementation, PyMORESANE. This thesis describes the implementation of PyMORESANE as well as its subsequent augmentation with MPU and GPGPU code. These additions accelerate the algorithm and thus make it competitive with its legacy counterparts. The acceleration of the algorithm is verified by means of benchmarking tests for varying image size and complexity. Additionally, PyMORESANE is shown to work not only on synthetic data, but on real observational data. This verification means that the MORESANE algorithm, and consequently the PyMORESANE implementation, can be added to the current arsenal of deconvolution tools.
- Full Text:
- Date Issued: 2015