'Environmental policy to community action': methodology and approaches in community-based environmental education programmes in Uganda
- Authors: Babikwa, Daniel J
- Date: 2004
- Subjects: Environmental education -- Uganda -- Case studies Education and state -- Uganda Community development -- Uganda -- Case studies Sustainable development -- Uganda -- Case studies Environmental policy -- Uganda -- Case studies
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1518 , http://hdl.handle.net/10962/d1003400
- Description: This research was conducted in Luwero, a rural district in central Uganda, over a period of three years, half of which entailed fulltime engagement in a participatory action research process with VEDCO, an indigenous NGO. The study focuses on the educational processes involved in the translation of Uganda's environmental policy into action at community level. It looks at community-based education and development activities run by VEDCO among smallholder farmers. The study addressed four objectives. For the first objective I developed a conceptual framework through a review of theories informing education in general and environmental education, adult education, community education, and community development in particular. The second objective was to conduct a situational analysis to identify contextual issues related to policy implementation at community level. The third objective was to engage in a participatory action research process with the NGO in the farming community in response to the identified contextual issues, and the fourth was to explore and comment on environmental education methods used within a community context. PRA techniques, interviews, and other participatory data collection methods were used to generate the data. The study reveals contradictions that limit NGO capacity to make appropriate use of participatory education processes in implementing policy-related training at community level. Elements in the National Plan for the Modernisation of Agriculture, for example, conflicted with the principle of sustainable development underlying the policy. VEDCO itself was changing from a social-welfare-oriented organisation into a commercial enterprise pursuing economic goals, which conflicted with its social goals. The capitalist development ideology of the donor was being adopted by VEDCO, which contradicted the goals of people-centred development. This was exacerbated by VEDCO's dependency on donor funds for its activities. Contextual issues like people's history; poverty, gender and inconsistent land policies further complicated the policy implementation processes. There were also inconsistencies in the epistemological assumptions and didactic approaches evident in the implementation. The study shows that the intended emancipatory education processes are more often supplanted by technicist methodologies. Thus, it exposes the underlying historical, ideological and epistemological tensions and contradictions within the field of education, particularly in relation to the `paradigmatic' orientations (neo-classical, liberal and socially critical/emancipatory) outlined in the literature. Conclusions are made at two levels: in relation to the study goals, of examining policy implementation at community level and in terms of the study's contribution to the understanding of current education theory in the context of sustainable development among communities.
- Full Text:
- Date Issued: 2004
- Authors: Babikwa, Daniel J
- Date: 2004
- Subjects: Environmental education -- Uganda -- Case studies Education and state -- Uganda Community development -- Uganda -- Case studies Sustainable development -- Uganda -- Case studies Environmental policy -- Uganda -- Case studies
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1518 , http://hdl.handle.net/10962/d1003400
- Description: This research was conducted in Luwero, a rural district in central Uganda, over a period of three years, half of which entailed fulltime engagement in a participatory action research process with VEDCO, an indigenous NGO. The study focuses on the educational processes involved in the translation of Uganda's environmental policy into action at community level. It looks at community-based education and development activities run by VEDCO among smallholder farmers. The study addressed four objectives. For the first objective I developed a conceptual framework through a review of theories informing education in general and environmental education, adult education, community education, and community development in particular. The second objective was to conduct a situational analysis to identify contextual issues related to policy implementation at community level. The third objective was to engage in a participatory action research process with the NGO in the farming community in response to the identified contextual issues, and the fourth was to explore and comment on environmental education methods used within a community context. PRA techniques, interviews, and other participatory data collection methods were used to generate the data. The study reveals contradictions that limit NGO capacity to make appropriate use of participatory education processes in implementing policy-related training at community level. Elements in the National Plan for the Modernisation of Agriculture, for example, conflicted with the principle of sustainable development underlying the policy. VEDCO itself was changing from a social-welfare-oriented organisation into a commercial enterprise pursuing economic goals, which conflicted with its social goals. The capitalist development ideology of the donor was being adopted by VEDCO, which contradicted the goals of people-centred development. This was exacerbated by VEDCO's dependency on donor funds for its activities. Contextual issues like people's history; poverty, gender and inconsistent land policies further complicated the policy implementation processes. There were also inconsistencies in the epistemological assumptions and didactic approaches evident in the implementation. The study shows that the intended emancipatory education processes are more often supplanted by technicist methodologies. Thus, it exposes the underlying historical, ideological and epistemological tensions and contradictions within the field of education, particularly in relation to the `paradigmatic' orientations (neo-classical, liberal and socially critical/emancipatory) outlined in the literature. Conclusions are made at two levels: in relation to the study goals, of examining policy implementation at community level and in terms of the study's contribution to the understanding of current education theory in the context of sustainable development among communities.
- Full Text:
- Date Issued: 2004
The effects of selected proline-based cyclic dipeptides on growth and induction of apoptosis in cancer cells
- Authors: Brauns, Seth Clint Aron
- Date: 2004
- Subjects: Cyclic peptides , Antineoplastic agents -- Testing , Apoptosis
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:11088 , http://hdl.handle.net/10948/396 , Cyclic peptides , Antineoplastic agents -- Testing , Apoptosis
- Description: An increasing number of cyclic dipeptides (CDPs) have been shown to exhibit important biological activity including antifungal, antibacterial, anticonvulsant and immunomodulatory activity. Furthermore, some CDP derivatives have been shown to exhibit antitumour activity in vitro and in vivo. Several proline-based CDPs that exhibit biological activity have been detected in various processed foods and beverages. In the present study, the potential of seven proline-based CDPs to inhibit cancer cell growth was investigated in HT-29 (colon), HeLa (cervical), MCF-7 (breast) and WHCO3 (oesophageal) cancer cell lines. The CDPs used in this study were cyclo(Phe-Pro), cyclo(Tyr-Pro), cyclo(Gly-Pro), cyclo(Pro- Pro), cyclo(His-Pro), cyclo(Leu-Pro) and cyclo(Thr-Pro). The sulforhodamine B (SRB) cell growth assay was used in an initial screening phase to investigate the effects of the CDPs in HT-29, HeLa and MCF-7 cells. After exposing the cells to 10mM of the respective CDPs for 48 hours, the SRB assay results showed that only cyclo(Phe-Pro) exhibited more than 50% growth inhibition (p<0.01) in the three cell lines. The other CDPs showed comparatively marginal growth-inhibitory effects, except for cyclo(Tyr-Pro), which exhibited a pronounced effect in MCF-7 cells compared to HT-29 and HeLa cells. The MTT assay was used to confirm the SRB assay results for cyclo(Phe-Pro) and cyclo(Tyr-Pro), extending the investigation to the use of the fourth cell line WHCO3 and using a longer exposure time of 72 hours. The MTT assay demonstrated a dosedependent (0.008-10 mM) growth inhibition by cyclo(Phe-Pro) with an IC50 value of 4.04 ± 1.15 mM for HT-29 cells. Cyclo(Phe-Pro) was subsequently used to investigate whether the growth-inhibitory effects of this CDP were related to the induction of apoptosis in HT-29 cells. Hoechst 33342 staining showed that 5mM cyclo(Phe-Pro) induced characteristic chromatin condensation and nuclear fragmentation in 18.3 ± 2.8% (p<0.01) of HT-29 cells after 72 hours. Furthermore, annexin V binding revealed that HT-29 cells treated with 5 mM cyclo(Phe-Pro) displayed phosphatidylserine externalization after 48 hours. In addition, it was shown that 10 mM cyclo(Phe-Pro) induced poly(ADP-ribose)polymerase PARP cleavage, one of the hallmark events of apoptosis. The use of the broad-range caspase inhibitor Z-VAD-FMK, showed that this PARP cleavage was caspase-dependent, which in turn was confirmed by demonstrating an increase in caspase-3 activity (p<0.01) in cyclo(Phe- Pro)-treated HT-29 cells. In conclusion, these findings demonstrate that cyclo(Phe-Pro) inhibited the growth of HT- 29, MCF-7, HeLa and WHCO3 cells, and induced apoptosis in HT-29 colon cancer cells, suggesting the potential antitumour activity of cyclo(Phe-Pro)-related CDPs.
- Full Text:
- Date Issued: 2004
- Authors: Brauns, Seth Clint Aron
- Date: 2004
- Subjects: Cyclic peptides , Antineoplastic agents -- Testing , Apoptosis
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:11088 , http://hdl.handle.net/10948/396 , Cyclic peptides , Antineoplastic agents -- Testing , Apoptosis
- Description: An increasing number of cyclic dipeptides (CDPs) have been shown to exhibit important biological activity including antifungal, antibacterial, anticonvulsant and immunomodulatory activity. Furthermore, some CDP derivatives have been shown to exhibit antitumour activity in vitro and in vivo. Several proline-based CDPs that exhibit biological activity have been detected in various processed foods and beverages. In the present study, the potential of seven proline-based CDPs to inhibit cancer cell growth was investigated in HT-29 (colon), HeLa (cervical), MCF-7 (breast) and WHCO3 (oesophageal) cancer cell lines. The CDPs used in this study were cyclo(Phe-Pro), cyclo(Tyr-Pro), cyclo(Gly-Pro), cyclo(Pro- Pro), cyclo(His-Pro), cyclo(Leu-Pro) and cyclo(Thr-Pro). The sulforhodamine B (SRB) cell growth assay was used in an initial screening phase to investigate the effects of the CDPs in HT-29, HeLa and MCF-7 cells. After exposing the cells to 10mM of the respective CDPs for 48 hours, the SRB assay results showed that only cyclo(Phe-Pro) exhibited more than 50% growth inhibition (p<0.01) in the three cell lines. The other CDPs showed comparatively marginal growth-inhibitory effects, except for cyclo(Tyr-Pro), which exhibited a pronounced effect in MCF-7 cells compared to HT-29 and HeLa cells. The MTT assay was used to confirm the SRB assay results for cyclo(Phe-Pro) and cyclo(Tyr-Pro), extending the investigation to the use of the fourth cell line WHCO3 and using a longer exposure time of 72 hours. The MTT assay demonstrated a dosedependent (0.008-10 mM) growth inhibition by cyclo(Phe-Pro) with an IC50 value of 4.04 ± 1.15 mM for HT-29 cells. Cyclo(Phe-Pro) was subsequently used to investigate whether the growth-inhibitory effects of this CDP were related to the induction of apoptosis in HT-29 cells. Hoechst 33342 staining showed that 5mM cyclo(Phe-Pro) induced characteristic chromatin condensation and nuclear fragmentation in 18.3 ± 2.8% (p<0.01) of HT-29 cells after 72 hours. Furthermore, annexin V binding revealed that HT-29 cells treated with 5 mM cyclo(Phe-Pro) displayed phosphatidylserine externalization after 48 hours. In addition, it was shown that 10 mM cyclo(Phe-Pro) induced poly(ADP-ribose)polymerase PARP cleavage, one of the hallmark events of apoptosis. The use of the broad-range caspase inhibitor Z-VAD-FMK, showed that this PARP cleavage was caspase-dependent, which in turn was confirmed by demonstrating an increase in caspase-3 activity (p<0.01) in cyclo(Phe- Pro)-treated HT-29 cells. In conclusion, these findings demonstrate that cyclo(Phe-Pro) inhibited the growth of HT- 29, MCF-7, HeLa and WHCO3 cells, and induced apoptosis in HT-29 colon cancer cells, suggesting the potential antitumour activity of cyclo(Phe-Pro)-related CDPs.
- Full Text:
- Date Issued: 2004
A comparison of programming notations for a tertiary level introductory programming course
- Authors: Cilliers, Charmain Barbara
- Date: 2004
- Subjects: Computer programming -- Study and teaching (Higher) -- South Africa , Computer programmers -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:11093 , http://hdl.handle.net/10948/d1019679
- Description: Increasing pressure from national government to improve throughput at South African tertiary education institutions presents challenges to educators of introductory programming courses. In response, educators must adopt effective methods and strategies that encourage novice programmers to be successful in such courses. An approach that seeks to increase and maintain satisfactory throughput is the modification of the teaching model in these courses by adjusting presentation techniques. This thesis investigates the effect of integrating an experimental iconic programming notation and associated development environment with existing conventional textual technological support in the teaching model of a tertiary level introductory programming course. The investigation compares the performance achievement of novice programmers using only conventional textual technological support with that of novice programmers using the integrated iconic and conventional textual technological support. In preparation for the investigation, interpretation of existing knowledge on the behaviour of novice programmers while learning to program results in a novel framework of eight novice programmer requirements for technological support in an introductory programming course. This framework is applied in the examination of existing categories of technological support as well as in the design of new technological support for novice programmers learning to program. It thus provides information for the selection of existing and the design of new introductory programming technological support. The findings of the investigation suggest strong evidence that performance achievement of novice programmers in a tertiary level introductory programming course improves significantly with the inclusion of iconic technological support in the teaching model. The benefits are particularly evident in the portion of the novice programmer population who have been identified as being at risk of being successful in the course. Novice programmers identified as being at risk perform substantially better when using iconic technological support concurrently with conventional textual technological support than their equals who use only the latter form. Considerably more at risk novice programmers using the integrated form of technological support are in fact successful in the introductory programming course when compared with their counterparts who use conventional textual technological support only. The contributions of this thesis address deficiencies existing in current documented research. These contributions are primarily apparent in a number of distinct areas, namely: • formalisation of a novel framework of novice programmer requirements for technological support in an introductory programming course; • application of the framework as a formal evaluation technique; • application of the framework in the design of a visual iconic programming notation and development environment; • enhancement of existing empirical evidence and experimental research methodology typically applied to studies in programming; as well as • a proposal for a modified introductory programming course teaching model. The thesis has effectively applied substantial existing research on the cognitive model of the novice programmer as well as that on experimental technological support. The increase of throughput to a recommended rate of 75 percent in the tertiary level introductory programming course at the University of Port Elizabeth is attributed solely to the incorporation of iconic technological support in the teaching model of the course.
- Full Text:
- Date Issued: 2004
- Authors: Cilliers, Charmain Barbara
- Date: 2004
- Subjects: Computer programming -- Study and teaching (Higher) -- South Africa , Computer programmers -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:11093 , http://hdl.handle.net/10948/d1019679
- Description: Increasing pressure from national government to improve throughput at South African tertiary education institutions presents challenges to educators of introductory programming courses. In response, educators must adopt effective methods and strategies that encourage novice programmers to be successful in such courses. An approach that seeks to increase and maintain satisfactory throughput is the modification of the teaching model in these courses by adjusting presentation techniques. This thesis investigates the effect of integrating an experimental iconic programming notation and associated development environment with existing conventional textual technological support in the teaching model of a tertiary level introductory programming course. The investigation compares the performance achievement of novice programmers using only conventional textual technological support with that of novice programmers using the integrated iconic and conventional textual technological support. In preparation for the investigation, interpretation of existing knowledge on the behaviour of novice programmers while learning to program results in a novel framework of eight novice programmer requirements for technological support in an introductory programming course. This framework is applied in the examination of existing categories of technological support as well as in the design of new technological support for novice programmers learning to program. It thus provides information for the selection of existing and the design of new introductory programming technological support. The findings of the investigation suggest strong evidence that performance achievement of novice programmers in a tertiary level introductory programming course improves significantly with the inclusion of iconic technological support in the teaching model. The benefits are particularly evident in the portion of the novice programmer population who have been identified as being at risk of being successful in the course. Novice programmers identified as being at risk perform substantially better when using iconic technological support concurrently with conventional textual technological support than their equals who use only the latter form. Considerably more at risk novice programmers using the integrated form of technological support are in fact successful in the introductory programming course when compared with their counterparts who use conventional textual technological support only. The contributions of this thesis address deficiencies existing in current documented research. These contributions are primarily apparent in a number of distinct areas, namely: • formalisation of a novel framework of novice programmer requirements for technological support in an introductory programming course; • application of the framework as a formal evaluation technique; • application of the framework in the design of a visual iconic programming notation and development environment; • enhancement of existing empirical evidence and experimental research methodology typically applied to studies in programming; as well as • a proposal for a modified introductory programming course teaching model. The thesis has effectively applied substantial existing research on the cognitive model of the novice programmer as well as that on experimental technological support. The increase of throughput to a recommended rate of 75 percent in the tertiary level introductory programming course at the University of Port Elizabeth is attributed solely to the incorporation of iconic technological support in the teaching model of the course.
- Full Text:
- Date Issued: 2004
A psychoanalytic hermeneutic investigation of destructive narcissism
- Authors: De Wit, Estelle
- Date: 2013-06-04 , 2004
- Subjects: Narcissism Narcissism -- Treatment Psychoanalysis Death instinct Ego (Psychology) Self psychology
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3180 , http://hdl.handle.net/10962/d1008055
- Description: The purpose of this research was to investigate the clinical phenomenon of destructive narcissism. Contemporary Kleinian and neo-Kleinian theoretical perspectives provided the interpretative perspective on the complexities of inaccessible personalities and subtle forms of internal destructiveness. Four research questions were formulated to interrogate the individual and collective experiences of three male patients whose internal worlds seem to be governed by rigid intrapychic structures organized around the dictatorship of a constellation of seemingly impenetrable defensive strategies. These questions were as follows: 1. What emotional states, actions and experiences of self and others characterize the clinical phenomenon designed as destructive narcissism and distinguish it from other forms of character pathology? 2. What early developmental experiences and relationships may have pre-disposed individuals to the development of this type of character pathology? 3. How are the psychodynamic processes of destructive narcissism structured and configured in the psychotherapeutic process and progress? 4. What are the transference/countertransference psychotherapeutic manifestations of the psychodynamics of destructive narcissism? The illustrative-didactic case study method was utilized to discuss pertinent aspects of each patient. This included their early developmental histories, inter- and intrapersonal relationships, their current mental state, defensive strategies and their stated reasons for commencing psychotherapy. In addition, the structure of the psychotherapeutic process with these patients was reviewed in depth. Various psychic and personality features, as unveiled through this process were discussed, as well as the implications of these for the therapeutic endeavor. The features chosen for discussion were: Firstly, the constellation of the internal object world, the capacity for symbolic thought and defensive organizations. Secondly, therapeutic ambivalence, which made psychotherapy untenable, was explored in conjunction with transference/countertransference issues. Thirdly, the shadow sides of psychotherapeutic change with these patients were considered and the issues of therapeutic failure and other treatment possibilities were examined. It was concluded that there need be an important shift with regard to the psychotherapeutic goals for those patients whose condition may be chronic, and for whom it appears that psychotherapy is of little benefit. In essence, the intent of psychotherapy with these patients is to reach the healthy sane patient of the patient within the pathological organization. Attempts to unravel the perverse gratification and protection derived from the domination of the narcissistic structure may not be enough, and the patient's collusion with the internal destructive gang should also be exposed. If this can be achieved, the patient may come to accept the existence of a part of himself as truly destructive. This, in turn, cannot be disowned, therefore the patient has to live with it. Thus, in destructive narcissism, the challenge for the therapist is the extremely difficult task of disentangling the patient's pain from the idealization of internal destructiveness. , KMBT_363 , Adobe Acrobat 9.54 Paper Capture Plug-in
- Full Text:
- Date Issued: 2004
- Authors: De Wit, Estelle
- Date: 2013-06-04 , 2004
- Subjects: Narcissism Narcissism -- Treatment Psychoanalysis Death instinct Ego (Psychology) Self psychology
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3180 , http://hdl.handle.net/10962/d1008055
- Description: The purpose of this research was to investigate the clinical phenomenon of destructive narcissism. Contemporary Kleinian and neo-Kleinian theoretical perspectives provided the interpretative perspective on the complexities of inaccessible personalities and subtle forms of internal destructiveness. Four research questions were formulated to interrogate the individual and collective experiences of three male patients whose internal worlds seem to be governed by rigid intrapychic structures organized around the dictatorship of a constellation of seemingly impenetrable defensive strategies. These questions were as follows: 1. What emotional states, actions and experiences of self and others characterize the clinical phenomenon designed as destructive narcissism and distinguish it from other forms of character pathology? 2. What early developmental experiences and relationships may have pre-disposed individuals to the development of this type of character pathology? 3. How are the psychodynamic processes of destructive narcissism structured and configured in the psychotherapeutic process and progress? 4. What are the transference/countertransference psychotherapeutic manifestations of the psychodynamics of destructive narcissism? The illustrative-didactic case study method was utilized to discuss pertinent aspects of each patient. This included their early developmental histories, inter- and intrapersonal relationships, their current mental state, defensive strategies and their stated reasons for commencing psychotherapy. In addition, the structure of the psychotherapeutic process with these patients was reviewed in depth. Various psychic and personality features, as unveiled through this process were discussed, as well as the implications of these for the therapeutic endeavor. The features chosen for discussion were: Firstly, the constellation of the internal object world, the capacity for symbolic thought and defensive organizations. Secondly, therapeutic ambivalence, which made psychotherapy untenable, was explored in conjunction with transference/countertransference issues. Thirdly, the shadow sides of psychotherapeutic change with these patients were considered and the issues of therapeutic failure and other treatment possibilities were examined. It was concluded that there need be an important shift with regard to the psychotherapeutic goals for those patients whose condition may be chronic, and for whom it appears that psychotherapy is of little benefit. In essence, the intent of psychotherapy with these patients is to reach the healthy sane patient of the patient within the pathological organization. Attempts to unravel the perverse gratification and protection derived from the domination of the narcissistic structure may not be enough, and the patient's collusion with the internal destructive gang should also be exposed. If this can be achieved, the patient may come to accept the existence of a part of himself as truly destructive. This, in turn, cannot be disowned, therefore the patient has to live with it. Thus, in destructive narcissism, the challenge for the therapist is the extremely difficult task of disentangling the patient's pain from the idealization of internal destructiveness. , KMBT_363 , Adobe Acrobat 9.54 Paper Capture Plug-in
- Full Text:
- Date Issued: 2004
An analysis of the censorship of popular music within the context of cultural struggle in South Africa during the 1980s
- Authors: Drewett, Michael
- Date: 2004
- Subjects: Censorship -- South Africa Popular music -- Censorship -- South Africa Popular music -- Censorship -- South Africa -- History Popular music -- Social aspects -- South Africa Popular music -- Political aspects -- South Africa Popular music -- South Africa -- History and criticism Protest songs -- South Africa -- History and criticism
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3350 , http://hdl.handle.net/10962/d1007098
- Description: The censorship of popular music in South Africa during the 1980s severely affected South African musicians. The apartheid government was directly involved in centralized state censorship by means of the Directorate of Publications, while the South African Broadcasting Corporation exercised government censorship at the level of airplay. Others who assisted state censorship included religious and cultural interest groups. State censorship in turn put pressure on record companies, musicians and others to practice self-censorship. Many musicians who overtly sang about taboo topics or who used controversial language subsequently experienced censorship in different forms, including police harassment. Musicians were also subject to anti-apartheid forms of censorship,such as the United Nations endorsed cultural boycott. Not all instances of censorship were overtly political, but they were always framed by, and took place within, a repressive legal-political system. This thesis found that despite the state's attempt to maintain its hegemony, musicians sought ways of overcoming censorship practices. It is argued that the ensuing struggle cannot be conceived of in simple binary terms. The works of Antonio Gramsci, Michel Foucault and Pierre Bourdieu, in particular, are applied to the South African context in exploring the localized nuances of the cultural struggle over music censorship. It is argued that fragmented resistance to censorship arose out of the very censorship structures that attempted to silence musicians. Textual analysis brought to light that resistance took various forms including songs with provocative lyrics and titles, and more subtle means of bypassing censorship, including the use of symbolism, camouflaged lyrics, satire and crossover performance. Musicians were faced with the challenge of bypassing censors yet nevertheless conveying their message to an audience. The most successful cases negotiated censorial practices while getting an apparent message across to a wide audience. Broader forms of resistance were also explored, including opposition through live performance, counter-hegemonic information on record covers, resistance from exile, alignment with political organizations and legal challenges to state censorship. In addition, some record companies developed strategies of resistance to censorship. The many innovative practices outlined in this thesis demonstrate that even in the context of constraint, resistance is possible. Despite censorship, South African musicians were able to express themselves through approaching their music in an innovative way.
- Full Text:
- Date Issued: 2004
- Authors: Drewett, Michael
- Date: 2004
- Subjects: Censorship -- South Africa Popular music -- Censorship -- South Africa Popular music -- Censorship -- South Africa -- History Popular music -- Social aspects -- South Africa Popular music -- Political aspects -- South Africa Popular music -- South Africa -- History and criticism Protest songs -- South Africa -- History and criticism
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3350 , http://hdl.handle.net/10962/d1007098
- Description: The censorship of popular music in South Africa during the 1980s severely affected South African musicians. The apartheid government was directly involved in centralized state censorship by means of the Directorate of Publications, while the South African Broadcasting Corporation exercised government censorship at the level of airplay. Others who assisted state censorship included religious and cultural interest groups. State censorship in turn put pressure on record companies, musicians and others to practice self-censorship. Many musicians who overtly sang about taboo topics or who used controversial language subsequently experienced censorship in different forms, including police harassment. Musicians were also subject to anti-apartheid forms of censorship,such as the United Nations endorsed cultural boycott. Not all instances of censorship were overtly political, but they were always framed by, and took place within, a repressive legal-political system. This thesis found that despite the state's attempt to maintain its hegemony, musicians sought ways of overcoming censorship practices. It is argued that the ensuing struggle cannot be conceived of in simple binary terms. The works of Antonio Gramsci, Michel Foucault and Pierre Bourdieu, in particular, are applied to the South African context in exploring the localized nuances of the cultural struggle over music censorship. It is argued that fragmented resistance to censorship arose out of the very censorship structures that attempted to silence musicians. Textual analysis brought to light that resistance took various forms including songs with provocative lyrics and titles, and more subtle means of bypassing censorship, including the use of symbolism, camouflaged lyrics, satire and crossover performance. Musicians were faced with the challenge of bypassing censors yet nevertheless conveying their message to an audience. The most successful cases negotiated censorial practices while getting an apparent message across to a wide audience. Broader forms of resistance were also explored, including opposition through live performance, counter-hegemonic information on record covers, resistance from exile, alignment with political organizations and legal challenges to state censorship. In addition, some record companies developed strategies of resistance to censorship. The many innovative practices outlined in this thesis demonstrate that even in the context of constraint, resistance is possible. Despite censorship, South African musicians were able to express themselves through approaching their music in an innovative way.
- Full Text:
- Date Issued: 2004
Integrated anaerobic/aerobic bioprocess environments and the biodegradation of complex hydrocarbon wastes
- Authors: Ehlers, George A C
- Date: 2004
- Subjects: Hydrocarbons -- Biodegradation Sewage -- Purification -- Anaerobic treatment Water -- Purification -- Biological treatment Anaerobic bacteria Aerobic bacteria
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4011 , http://hdl.handle.net/10962/d1004071
- Description: An investigation of the biodegradation of complex hydrocarbon wastes, with emphasis on chlorinated aromatic compounds, in an anaerobic/aerobic bioprocess environment was made. A reactor configuration was developed consisting of linked anaerobic and aerobic reactors which served as the model for a proposed bioremediation strategy targeting subterranean soil/sediment/aquifer chlorinated phenol-contaminated environments. Here oxygen is frequently limited and sulphate is readily available, as occurs especially in marine sediment and intertidal habitats. In the anaerobic system the successful transformation and mobilization of the model contaminant, 2,4,6-trichlorophenol, was shown to rely on reductive dechlorination by a sulphate-reducing dependent dechlororespiring co-culture. This was followed in the aerobic system by degradation of the pollutant and its metabolites, 2,4-dichlorophenol, 4-chlorophenol and phenol, by immobilized white-rot fungi.The strategy was initially investigated separately in laboratory bench- and intermediate scale reactors whereafter reactors were linked to simulate the integrated biodegradation strategy. The application of the fungal reactor to treat an actual waste stream by degrading complex mixtures of hydrocarbons in a waste oil recycling effluent was also investigated. The mineralization of phenol and 2,4,6-TCP by immobilized fungal cultures was studied in pinewood chip and foam glass bead-packed trickling reactors. The reactors were operated in sequencing batch format. Removal efficiency increased over time and elevated influent phenol and TCP (800 and 85 mg.L⁻¹) concentrations were degraded by > 98 % in 24 – 30 h batch cycles. Comparable performance between the packing materials was shown. Uptake by the packing was negligible and stripping of compounds induced by aeration had a minimal effect on biodegradation efficiency. Reactor performances are discussed in relation to sequencing batch operation and nutrient requirements necessary to sustain fungal activity in inert vs. organic material packed systems. It was shown that a co-culture consisting of sulphate-reducing and dechlororespiring bacteria established in fed-batch and soil flasks, as well as pine chip-packed fluidized bed reactors. Results showed reductive dechlorination of 2,4,6-TCP to be in strict dependence on the activity of the sulphate-reducing population, sulphate and lactate concentrations. Transformation to 2,4-DCP, 4-CP and phenol was enhanced in sulphate deficient conditions. Dechlororespiring activity was found to be dependent on the fermentative activity of sulphate-reducing bacteria, and the culture was also shown to mobilize and dechlorinate TCP in soils contaminated with the pollutant. Linking the systems achieved degradation of the compound by > 99 % through fungal mineralization of metabolites produced in the dechlororespiring stage of the system. pH correction to the anaerobic reactor was found to be necessary since acidic effluent from the fungal reactor inhibited sulphate reduction and dechlorination. The fungal reactor system was evaluated at intermediate-scale using a complex waste oil recycling effluent. Substantial COD reduction (> 96 % in 48 h batch cycles) and removal of specific effluent hydrocarbon components was shown in diluted, undiluted (COD > 37 g.L⁻¹) and 2,4,6-TCP-spiked effluents. Industrial application of the fungal reactor was evaluated in a 14 m³ pilot plant operated on-site at a waste oil processing plant.
- Full Text:
- Date Issued: 2004
- Authors: Ehlers, George A C
- Date: 2004
- Subjects: Hydrocarbons -- Biodegradation Sewage -- Purification -- Anaerobic treatment Water -- Purification -- Biological treatment Anaerobic bacteria Aerobic bacteria
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4011 , http://hdl.handle.net/10962/d1004071
- Description: An investigation of the biodegradation of complex hydrocarbon wastes, with emphasis on chlorinated aromatic compounds, in an anaerobic/aerobic bioprocess environment was made. A reactor configuration was developed consisting of linked anaerobic and aerobic reactors which served as the model for a proposed bioremediation strategy targeting subterranean soil/sediment/aquifer chlorinated phenol-contaminated environments. Here oxygen is frequently limited and sulphate is readily available, as occurs especially in marine sediment and intertidal habitats. In the anaerobic system the successful transformation and mobilization of the model contaminant, 2,4,6-trichlorophenol, was shown to rely on reductive dechlorination by a sulphate-reducing dependent dechlororespiring co-culture. This was followed in the aerobic system by degradation of the pollutant and its metabolites, 2,4-dichlorophenol, 4-chlorophenol and phenol, by immobilized white-rot fungi.The strategy was initially investigated separately in laboratory bench- and intermediate scale reactors whereafter reactors were linked to simulate the integrated biodegradation strategy. The application of the fungal reactor to treat an actual waste stream by degrading complex mixtures of hydrocarbons in a waste oil recycling effluent was also investigated. The mineralization of phenol and 2,4,6-TCP by immobilized fungal cultures was studied in pinewood chip and foam glass bead-packed trickling reactors. The reactors were operated in sequencing batch format. Removal efficiency increased over time and elevated influent phenol and TCP (800 and 85 mg.L⁻¹) concentrations were degraded by > 98 % in 24 – 30 h batch cycles. Comparable performance between the packing materials was shown. Uptake by the packing was negligible and stripping of compounds induced by aeration had a minimal effect on biodegradation efficiency. Reactor performances are discussed in relation to sequencing batch operation and nutrient requirements necessary to sustain fungal activity in inert vs. organic material packed systems. It was shown that a co-culture consisting of sulphate-reducing and dechlororespiring bacteria established in fed-batch and soil flasks, as well as pine chip-packed fluidized bed reactors. Results showed reductive dechlorination of 2,4,6-TCP to be in strict dependence on the activity of the sulphate-reducing population, sulphate and lactate concentrations. Transformation to 2,4-DCP, 4-CP and phenol was enhanced in sulphate deficient conditions. Dechlororespiring activity was found to be dependent on the fermentative activity of sulphate-reducing bacteria, and the culture was also shown to mobilize and dechlorinate TCP in soils contaminated with the pollutant. Linking the systems achieved degradation of the compound by > 99 % through fungal mineralization of metabolites produced in the dechlororespiring stage of the system. pH correction to the anaerobic reactor was found to be necessary since acidic effluent from the fungal reactor inhibited sulphate reduction and dechlorination. The fungal reactor system was evaluated at intermediate-scale using a complex waste oil recycling effluent. Substantial COD reduction (> 96 % in 48 h batch cycles) and removal of specific effluent hydrocarbon components was shown in diluted, undiluted (COD > 37 g.L⁻¹) and 2,4,6-TCP-spiked effluents. Industrial application of the fungal reactor was evaluated in a 14 m³ pilot plant operated on-site at a waste oil processing plant.
- Full Text:
- Date Issued: 2004
The ecology and control of small hive beetles (Aethina tumida Murray)
- Authors: Ellis, James Douglas
- Date: 2004
- Subjects: Bee culture , Bee culture -- United States , Nitidulidae , Beetles -- Ecology , Beetles -- Control
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5917 , http://hdl.handle.net/10962/d1016253
- Description: The small hive beetle (Aethina tumida Murray) is an endemic scavenger in colonies of honey bee (Apis mellifera L.) subspecies inhabiting sub-Saharan Africa. The beetle only occasionally damages host colonies in its native range and such damage is usually restricted to weakened/diseased colonies or is associated with after absconding events due to behavioral resistance mechanisms of its host. The beetle has recently been introduced into North America and Australia where populations of managed subspecies of European honey bees have proven highly susceptible to beetle depredation. Beetles are able to reproduce in large numbers in European colonies and their larvae weaken colonies by eating honey, pollen, and bee brood. Further, adult and larval defecation is thought to promote the fermentation of honey and large populations of beetles can cause European colonies to abscond, both resulting in additional colony damage. The economic losses attributed to the beetle since its introduction into the United States have been estimated in millions of US dollars. Although beetles feed on foodstuffs found within colonies, experiments in vitro show that they can also complete entire life cycles on fruit. Regardless, they reproduce best on diets of honey, pollen, and bee brood. After feeding, beetle larvae exit the colony and burrow into the ground where they pupate. Neither soil type nor density affects a beetle’s ability to successfully pupate. Instead, successful pupation appears to be closely tied to soil moisture. African subspecies of honey bees employ a complicated scheme of confinement (aggressive behavior toward and guarding of beetles) to limit beetle reproduction in a colony. Despite being confined away from food, adult beetles are able to solicit food and feed from the mouths of their honey bee guards. Remarkably, beetle-naïve European honey bees also confine beetles and this behavior is quantitatively similar to that in African bees. If confinement efforts fail, beetles access the combs where they feed and reproduce. Two modes of beetle oviposition in sealed bee brood have been identified. In the first mode, beetles bite holes in the cappings of cells and oviposit on the pupa contained within. In the second mode, beetles enter empty cells, bite a hole in the wall of the cell, and oviposit on the brood in the adjacent cell. Despite this, African bees detect and remove all of the infected brood (hygienic behavior). Similarly, European bees can detect and remove brood that has been oviposited on by beetles. Enhancing the removal rate of infected brood in European colonies through selective breeding may achieve genetic control of beetles. Additional avenues of control were tested for efficacy against beetles. Reducing colony entrances slowed beetle ingress but the efficacy of this method probably depends on other factors. Further, the mortality of beetle pupae was higher when contacting species of the fungus Aspergillus than when not, making biological control an option. Regardless, no control tested to date proved efficacious at the level needed by beekeepers so an integrated approach to controlling beetles remains preferred. The amalgamation of the data presented in this dissertation contributed to a discussion on the beetle’s ecological niche, ability to impact honey bee colonies in ways never considered, and the ability to predict the beetle’s spread and impact globally.
- Full Text:
- Date Issued: 2004
- Authors: Ellis, James Douglas
- Date: 2004
- Subjects: Bee culture , Bee culture -- United States , Nitidulidae , Beetles -- Ecology , Beetles -- Control
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5917 , http://hdl.handle.net/10962/d1016253
- Description: The small hive beetle (Aethina tumida Murray) is an endemic scavenger in colonies of honey bee (Apis mellifera L.) subspecies inhabiting sub-Saharan Africa. The beetle only occasionally damages host colonies in its native range and such damage is usually restricted to weakened/diseased colonies or is associated with after absconding events due to behavioral resistance mechanisms of its host. The beetle has recently been introduced into North America and Australia where populations of managed subspecies of European honey bees have proven highly susceptible to beetle depredation. Beetles are able to reproduce in large numbers in European colonies and their larvae weaken colonies by eating honey, pollen, and bee brood. Further, adult and larval defecation is thought to promote the fermentation of honey and large populations of beetles can cause European colonies to abscond, both resulting in additional colony damage. The economic losses attributed to the beetle since its introduction into the United States have been estimated in millions of US dollars. Although beetles feed on foodstuffs found within colonies, experiments in vitro show that they can also complete entire life cycles on fruit. Regardless, they reproduce best on diets of honey, pollen, and bee brood. After feeding, beetle larvae exit the colony and burrow into the ground where they pupate. Neither soil type nor density affects a beetle’s ability to successfully pupate. Instead, successful pupation appears to be closely tied to soil moisture. African subspecies of honey bees employ a complicated scheme of confinement (aggressive behavior toward and guarding of beetles) to limit beetle reproduction in a colony. Despite being confined away from food, adult beetles are able to solicit food and feed from the mouths of their honey bee guards. Remarkably, beetle-naïve European honey bees also confine beetles and this behavior is quantitatively similar to that in African bees. If confinement efforts fail, beetles access the combs where they feed and reproduce. Two modes of beetle oviposition in sealed bee brood have been identified. In the first mode, beetles bite holes in the cappings of cells and oviposit on the pupa contained within. In the second mode, beetles enter empty cells, bite a hole in the wall of the cell, and oviposit on the brood in the adjacent cell. Despite this, African bees detect and remove all of the infected brood (hygienic behavior). Similarly, European bees can detect and remove brood that has been oviposited on by beetles. Enhancing the removal rate of infected brood in European colonies through selective breeding may achieve genetic control of beetles. Additional avenues of control were tested for efficacy against beetles. Reducing colony entrances slowed beetle ingress but the efficacy of this method probably depends on other factors. Further, the mortality of beetle pupae was higher when contacting species of the fungus Aspergillus than when not, making biological control an option. Regardless, no control tested to date proved efficacious at the level needed by beekeepers so an integrated approach to controlling beetles remains preferred. The amalgamation of the data presented in this dissertation contributed to a discussion on the beetle’s ecological niche, ability to impact honey bee colonies in ways never considered, and the ability to predict the beetle’s spread and impact globally.
- Full Text:
- Date Issued: 2004
The enzymology of enhanced hydrolysis within the biosulphidogenic recycling sludge bed reactor (RSBR)
- Authors: Enongene, Godlove Nkwelle
- Date: 2004
- Subjects: Hydrolysis , Sewage sludge , Sewage -- Purification -- Anaerobic treatment , Water -- Purification -- Biological treatment
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4132 , http://hdl.handle.net/10962/d1015744
- Description: The hydrolysis of complex organic heteropolymers contained in municipal wastewater to simpler monomers by extracellular hydrolytic enzymes is generally considered the rate-limiting step of the biodegradation process. Previous studies of the Recycling Sludge Bed Reactor (RSBR) revealed that the hydrolysis of complex particulate organics, such as those contained in primary sludge (PS), was enhanced under anaerobic biosulphidogenic conditions. Although the mechanism was not fully understood, it appeared to involve the interaction of sulfide and sludge flocs. The current study was conducted using a 3500 ml laboratory-scale RSBR fed sieved PS at a loading rate of 0.5 kg COD/m³.day and an initial chemical oxygen demand (COD) to sulfate ratio (COD:SO₄) of 1:1. There was no significant accumulation of undigested sludge in the reactor over the 60-day experimental period and the quantity of SO₄ reduced indicated that the yield of soluble products from PS was at least as high as those reported previously for this system (> 50%). In the current study, the specific activities of a range of extracellular hydrolytic enzymes (L-alanine aminopeptidase, L-leucine aminopeptidase, arylsulphatase, α-glucosidase, β- glucosidase, protease and lipase) were monitored in a sulfide gradient within a biosulphidogenic RSBR. Data obtained indicated that the specific enzymatic activities increased with the depth of the RSBR and also correlated with a number of the physicochemical parameters including sulfide, alkalinity and sulfate. The activities of α- glucosidase and β-glucosidase were higher than that of the other enzymes studied. Lipase activity was relatively low and studies conducted on the enzyme-enzyme interaction using specific enzyme inhibitors indicated that lipases were probably being digested by the proteases. Further studies to determine the impact of sulfide on the enzymes, showed an increase in the enzyme activity with increasing sulfide concentration. Possible direct affects were investigated by looking for changes in the Michaelis constant (Km) and the maximal velocity (Vmax) of the crude enzymes with varying sulfide concentrations (250, 400 and 500 mg/l) using natural and synthetic substrates. The results showed no significant difference in both the Km and the Vmax for any of the hydrolytic enzymes except for the protease. The latter showed a statistically significant increase in the Km with increasing sulfide concentration. Although this indicated a direct interaction, this difference was not large enough to be of biochemical significance and was consequently not solely responsible for the enhanced hydrolysis observed in the RSBR. Investigation into the floc characteristics indicated that the biosulphidogenic RSBR flocs were generally small in size and became more dendritic with the depth of the RSBR. Based on the above data, the previously proposed descriptive models of enhanced hydrolysis of particulate organic matter in a biosulphidogenic RSBR has been revised. It is thought that the effect of sulfide on the hydrolysis step is primarily indirect and that the reduction in floc size and alteration of the floc shape to a more dendritic form is central to the success of the process.
- Full Text:
- Date Issued: 2004
- Authors: Enongene, Godlove Nkwelle
- Date: 2004
- Subjects: Hydrolysis , Sewage sludge , Sewage -- Purification -- Anaerobic treatment , Water -- Purification -- Biological treatment
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4132 , http://hdl.handle.net/10962/d1015744
- Description: The hydrolysis of complex organic heteropolymers contained in municipal wastewater to simpler monomers by extracellular hydrolytic enzymes is generally considered the rate-limiting step of the biodegradation process. Previous studies of the Recycling Sludge Bed Reactor (RSBR) revealed that the hydrolysis of complex particulate organics, such as those contained in primary sludge (PS), was enhanced under anaerobic biosulphidogenic conditions. Although the mechanism was not fully understood, it appeared to involve the interaction of sulfide and sludge flocs. The current study was conducted using a 3500 ml laboratory-scale RSBR fed sieved PS at a loading rate of 0.5 kg COD/m³.day and an initial chemical oxygen demand (COD) to sulfate ratio (COD:SO₄) of 1:1. There was no significant accumulation of undigested sludge in the reactor over the 60-day experimental period and the quantity of SO₄ reduced indicated that the yield of soluble products from PS was at least as high as those reported previously for this system (> 50%). In the current study, the specific activities of a range of extracellular hydrolytic enzymes (L-alanine aminopeptidase, L-leucine aminopeptidase, arylsulphatase, α-glucosidase, β- glucosidase, protease and lipase) were monitored in a sulfide gradient within a biosulphidogenic RSBR. Data obtained indicated that the specific enzymatic activities increased with the depth of the RSBR and also correlated with a number of the physicochemical parameters including sulfide, alkalinity and sulfate. The activities of α- glucosidase and β-glucosidase were higher than that of the other enzymes studied. Lipase activity was relatively low and studies conducted on the enzyme-enzyme interaction using specific enzyme inhibitors indicated that lipases were probably being digested by the proteases. Further studies to determine the impact of sulfide on the enzymes, showed an increase in the enzyme activity with increasing sulfide concentration. Possible direct affects were investigated by looking for changes in the Michaelis constant (Km) and the maximal velocity (Vmax) of the crude enzymes with varying sulfide concentrations (250, 400 and 500 mg/l) using natural and synthetic substrates. The results showed no significant difference in both the Km and the Vmax for any of the hydrolytic enzymes except for the protease. The latter showed a statistically significant increase in the Km with increasing sulfide concentration. Although this indicated a direct interaction, this difference was not large enough to be of biochemical significance and was consequently not solely responsible for the enhanced hydrolysis observed in the RSBR. Investigation into the floc characteristics indicated that the biosulphidogenic RSBR flocs were generally small in size and became more dendritic with the depth of the RSBR. Based on the above data, the previously proposed descriptive models of enhanced hydrolysis of particulate organic matter in a biosulphidogenic RSBR has been revised. It is thought that the effect of sulfide on the hydrolysis step is primarily indirect and that the reduction in floc size and alteration of the floc shape to a more dendritic form is central to the success of the process.
- Full Text:
- Date Issued: 2004
The concentration of ten metals in the tissues of shark species Squalus megalops and Mustelus mustelus (Chondrichthyes) occuring along the Southeastern coast of South Africa
- Erasmus, Christina Petronella
- Authors: Erasmus, Christina Petronella
- Date: 2004
- Subjects: Sharks -- South Africa -- Effect of metals on. , Marine pollutio -- South Africa.
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:11095 , http://hdl.handle.net/10948/d1019683
- Description: The southeastern coast of South Africa is deemed unpolluted and with the exception of a few localized areas, is believed to be pristine. This study aimed to (1) assess the concentration of metals in the water and sharks (Squalus megalops, Mustelus mustelus) from different sites along the southeastern coast, (2) determine the effects that metals have on each other and investigate the accumulation and storage of metals in different shark tissues, (3) determine the effects of length and sex on metal concentration and the presence of metallothioneins in the liver. Metal concentrations in water from seven sites along the southeastern coast revealed concentrations below the detection limit of the extraction method, except for iron at St. Francis Bay which was below the recommended levels as supplied by DWAF. Met al concentrations in S. megalops from the seven sites revealed significantly elevated levels in individuals from Algoa and St. Francis Bay when compared to the other 5 sites. This was observed for all metals except manganese, which had a higher concentration at Cape Agulhas. After comparing the metal levels in muscle tissue (S. megalops) with data from the Department of Health it was concluded that the sharks caught at Algoa and St. Francis Bay were unsuited for human consumption. Liver and vertebral tissues from both S. megalops and M. mustelus were deemed unsuited for human consumption but further research should be conducted especially on vertebral metal concentrations. Comparing the metal concentration in different tissue types of S. megalops and M. mustelus significant difference were observed and attributed to differences in the maturity (thus age) of the two species. Significant differences in the metal concentration of males and females for both the species were observed. A higher number of differences were however observed in M. mustelus than in S. megalops, most probably due to the differences in maturity. Length and weight vs. metal concentration regressions in the males and females of both species revealed more negative than positive trends. This was found to be in accordance with other studies from around the world. Using the life stages of S. megalops, significant differences in the average concentration of metals were observed between the life stages, with embryos usually having the highest concentration. The metal concentration series determined for S. megalops were similar to that which have been reported in the literature in that iron and zinc occupied the highest concentration positions while cadmium, copper and manganese occupied the last three. The spleen usually had the highest metal concentration except for aluminium in skin and arsenic in muscle tissue. Pearson correlation revealed significant negative correlations between cadmium and the mentioned metals suggesting that cadmium replaces essential metals such as manganese, iron and copper as. Negative correlations between essential metals were observed most probably due to the competition for binding positions on ligands. Positive correlations were observed between metals in sp ecific tissue types and may be indicative of synergistic effects, e.g. aluminium may result in the accumulation of other metals such as cadmium. Positive and negative correlations between a specific metal and different tissue types have also been observed and it appears that there are movement of metals between tissue types. Positive correlation for essential metals between yolk and other tissue have been observed, although no correlations for non-essential metals were observed. This could potentially indicate a mechanism that prevents the accumulation of nonessential metals in embryos. Though no metallothioneins were isolated form the liver, the presence of cadmium in other proteins indicate that that cadmium is substituted for essential metals, and as this may result in deleterious physiological effects, further studies should be conducted. In conclusion it can be said that although some of the results were expected there are still quite a few unanswered question and further studies should be conducted.
- Full Text:
- Date Issued: 2004
- Authors: Erasmus, Christina Petronella
- Date: 2004
- Subjects: Sharks -- South Africa -- Effect of metals on. , Marine pollutio -- South Africa.
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:11095 , http://hdl.handle.net/10948/d1019683
- Description: The southeastern coast of South Africa is deemed unpolluted and with the exception of a few localized areas, is believed to be pristine. This study aimed to (1) assess the concentration of metals in the water and sharks (Squalus megalops, Mustelus mustelus) from different sites along the southeastern coast, (2) determine the effects that metals have on each other and investigate the accumulation and storage of metals in different shark tissues, (3) determine the effects of length and sex on metal concentration and the presence of metallothioneins in the liver. Metal concentrations in water from seven sites along the southeastern coast revealed concentrations below the detection limit of the extraction method, except for iron at St. Francis Bay which was below the recommended levels as supplied by DWAF. Met al concentrations in S. megalops from the seven sites revealed significantly elevated levels in individuals from Algoa and St. Francis Bay when compared to the other 5 sites. This was observed for all metals except manganese, which had a higher concentration at Cape Agulhas. After comparing the metal levels in muscle tissue (S. megalops) with data from the Department of Health it was concluded that the sharks caught at Algoa and St. Francis Bay were unsuited for human consumption. Liver and vertebral tissues from both S. megalops and M. mustelus were deemed unsuited for human consumption but further research should be conducted especially on vertebral metal concentrations. Comparing the metal concentration in different tissue types of S. megalops and M. mustelus significant difference were observed and attributed to differences in the maturity (thus age) of the two species. Significant differences in the metal concentration of males and females for both the species were observed. A higher number of differences were however observed in M. mustelus than in S. megalops, most probably due to the differences in maturity. Length and weight vs. metal concentration regressions in the males and females of both species revealed more negative than positive trends. This was found to be in accordance with other studies from around the world. Using the life stages of S. megalops, significant differences in the average concentration of metals were observed between the life stages, with embryos usually having the highest concentration. The metal concentration series determined for S. megalops were similar to that which have been reported in the literature in that iron and zinc occupied the highest concentration positions while cadmium, copper and manganese occupied the last three. The spleen usually had the highest metal concentration except for aluminium in skin and arsenic in muscle tissue. Pearson correlation revealed significant negative correlations between cadmium and the mentioned metals suggesting that cadmium replaces essential metals such as manganese, iron and copper as. Negative correlations between essential metals were observed most probably due to the competition for binding positions on ligands. Positive correlations were observed between metals in sp ecific tissue types and may be indicative of synergistic effects, e.g. aluminium may result in the accumulation of other metals such as cadmium. Positive and negative correlations between a specific metal and different tissue types have also been observed and it appears that there are movement of metals between tissue types. Positive correlation for essential metals between yolk and other tissue have been observed, although no correlations for non-essential metals were observed. This could potentially indicate a mechanism that prevents the accumulation of nonessential metals in embryos. Though no metallothioneins were isolated form the liver, the presence of cadmium in other proteins indicate that that cadmium is substituted for essential metals, and as this may result in deleterious physiological effects, further studies should be conducted. In conclusion it can be said that although some of the results were expected there are still quite a few unanswered question and further studies should be conducted.
- Full Text:
- Date Issued: 2004
The concentration of ten metals in the tissues of shark species Squalus megalops and Mustelus mustelus (chondrichthyes) occuring along the Southeastern coast of South Africa
- Erasmus, Christina Petronella
- Authors: Erasmus, Christina Petronella
- Date: 2004
- Subjects: Sharks -- South Africa -- Effect of metals on , Marine pollution -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:11085 , http://hdl.handle.net/10948/328 , Sharks -- South Africa -- Effect of metals on , Marine pollution -- South Africa
- Description: The southeastern coast of South Africa is deemed unpolluted and with the exception of a few localized areas, is believed to be pristine. This study aimed to (1) assess the concentration of metals in the water and sharks (Squalus megalops, Mustelus mustelus) from different sites along the southeastern coast, (2) determine the effects that metals have on each other and investigate the accumulation and storage of metals in different shark tissues, (3) determine the effects of length and sex on metal concentration and the presence of metallothioneins in the liver. Metal concentrations in water from seven sites along the southeastern coast revealed concentrations below the detection limit of the extraction method, except for iron at St. Francis Bay which was below the recommended levels as supplied by DWAF. Met al concentrations in S. megalops from the seven sites revealed significantly elevated levels in individuals from Algoa and St. Francis Bay when compared to the other 5 sites. This was observed for all metals except manganese, which had a higher concentration at Cape Agulhas. After comparing the metal levels in muscle tissue (S. megalops) with data from the Department of Health it was concluded that the sharks caught at Algoa and St. Francis Bay were unsuited for human consumption. Liver and vertebral tissues from both S. megalops and M. mustelus were deemed unsuited for human consumption but further research should be conducted especially on vertebral metal concentrations. Comparing the metal concentration in different tissue types of S. megalops and M. mustelus significant difference were observed and attributed to differences in the maturity (thus age) of the two species. Significant differences in the metal concentration of males and females for both the species were observed. A higher number of differences were however observed in M. mustelus than in S. megalops, most probably due to the differences in maturity. Length and weight vs. metal concentration regressions in the males and females of both species revealed more negative than positive trends. This was found to be in accordance with other studies from around the world. Using the life stages of S. megalops, significant differences in the average concentration of metals were observed between the life stages, with embryos usually having the highest concentration. The metal concentration series determined for S. megalops were similar to that which have been reported in the literature in that iron and zinc occupied the highest concentration positions while cadmium, copper and manganese occupied the last three. The spleen usually had the highest metal concentration except for aluminium in skin and arsenic in muscle tissue. Pearson correlation revealed significant negative correlations between cadmium and the mentioned metals suggesting that cadmium replaces essential metals such as manganese, iron and copper as. Negative correlations between essential metals were observed most probably due to the competition for binding positions on ligands. Positive correlations were observed between metals in sp ecific tissue types and may be indicative of synergistic effects, e.g. aluminium may result in the accumulation of other metals such as cadmium. Positive and negative correlations between a specific metal and different tissue types have also been observed and it appears that there are movement of metals between tissue types. Positive correlation for essential metals between yolk and other tissue have been observed, although no correlations for non-essential metals were observed. This could potentially indicate a mechanism that prevents the accumulation of nonessential metals in embryos. Though no metallothioneins were isolated form the liver, the presence of cadmium in other proteins indicate that that cadmium is substituted for essential metals, and as this may result in deleterious physiological effects, further studies should be conducted. In conclusion it can be said that although some of the results were expected there are still quite a few unanswered question and further studies should be conducted.
- Full Text:
- Date Issued: 2004
- Authors: Erasmus, Christina Petronella
- Date: 2004
- Subjects: Sharks -- South Africa -- Effect of metals on , Marine pollution -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:11085 , http://hdl.handle.net/10948/328 , Sharks -- South Africa -- Effect of metals on , Marine pollution -- South Africa
- Description: The southeastern coast of South Africa is deemed unpolluted and with the exception of a few localized areas, is believed to be pristine. This study aimed to (1) assess the concentration of metals in the water and sharks (Squalus megalops, Mustelus mustelus) from different sites along the southeastern coast, (2) determine the effects that metals have on each other and investigate the accumulation and storage of metals in different shark tissues, (3) determine the effects of length and sex on metal concentration and the presence of metallothioneins in the liver. Metal concentrations in water from seven sites along the southeastern coast revealed concentrations below the detection limit of the extraction method, except for iron at St. Francis Bay which was below the recommended levels as supplied by DWAF. Met al concentrations in S. megalops from the seven sites revealed significantly elevated levels in individuals from Algoa and St. Francis Bay when compared to the other 5 sites. This was observed for all metals except manganese, which had a higher concentration at Cape Agulhas. After comparing the metal levels in muscle tissue (S. megalops) with data from the Department of Health it was concluded that the sharks caught at Algoa and St. Francis Bay were unsuited for human consumption. Liver and vertebral tissues from both S. megalops and M. mustelus were deemed unsuited for human consumption but further research should be conducted especially on vertebral metal concentrations. Comparing the metal concentration in different tissue types of S. megalops and M. mustelus significant difference were observed and attributed to differences in the maturity (thus age) of the two species. Significant differences in the metal concentration of males and females for both the species were observed. A higher number of differences were however observed in M. mustelus than in S. megalops, most probably due to the differences in maturity. Length and weight vs. metal concentration regressions in the males and females of both species revealed more negative than positive trends. This was found to be in accordance with other studies from around the world. Using the life stages of S. megalops, significant differences in the average concentration of metals were observed between the life stages, with embryos usually having the highest concentration. The metal concentration series determined for S. megalops were similar to that which have been reported in the literature in that iron and zinc occupied the highest concentration positions while cadmium, copper and manganese occupied the last three. The spleen usually had the highest metal concentration except for aluminium in skin and arsenic in muscle tissue. Pearson correlation revealed significant negative correlations between cadmium and the mentioned metals suggesting that cadmium replaces essential metals such as manganese, iron and copper as. Negative correlations between essential metals were observed most probably due to the competition for binding positions on ligands. Positive correlations were observed between metals in sp ecific tissue types and may be indicative of synergistic effects, e.g. aluminium may result in the accumulation of other metals such as cadmium. Positive and negative correlations between a specific metal and different tissue types have also been observed and it appears that there are movement of metals between tissue types. Positive correlation for essential metals between yolk and other tissue have been observed, although no correlations for non-essential metals were observed. This could potentially indicate a mechanism that prevents the accumulation of nonessential metals in embryos. Though no metallothioneins were isolated form the liver, the presence of cadmium in other proteins indicate that that cadmium is substituted for essential metals, and as this may result in deleterious physiological effects, further studies should be conducted. In conclusion it can be said that although some of the results were expected there are still quite a few unanswered question and further studies should be conducted.
- Full Text:
- Date Issued: 2004
Development of a hydantoin-hydrolysing biocatalyst for the production of optically pure amino acids using Agrobacterium tumefaciens strain RU-ORPN1
- Authors: Foster, Ingrid Margaret
- Date: 2004
- Subjects: Agrobacterium tumefaciens Amino acids Hydantoin Hydrolysis Enzymes
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3943 , http://hdl.handle.net/10962/d1004002
- Description: A calcium alginate bead-immobilised biocatalyst was developed utilising the D-hydantoinase and D-N-carbamoylase from a novel, mutant Agrobacterium tumefaciens strain RU-ORPN1. The growth conditions for the inducer-independent strain were optimised for production of hydantoinase and N-carbamoylase activities. Methods for the preparation of crude enzyme extracts were evaluated in terms of hydantoinase and N-carbamoylase activities produced. After comparison of the enzyme activities and stabilities in various extracts from fresh and frozen cells, sonication of frozen cells for 5 minutes was found to be the best method for the production of the enzyme extract. The optimal pH and temperature for the hydantoinase activity were pH 10 and 30°C, respectively, while pH 9 and 40°C were optimal for Ncarbamoylase activity. The hydantoinase activity was enhanced by the addition of Mg^(2+) ions to the enzyme extract and the N-carbamoylase was enhanced by the addition of Mg^(2+), Mn^(2+) or Zn^(2+) ions to the enzyme extract. The enzyme activities increased in the presence of ATP suggesting that the enzymes may be ATP-dependent. The addition of DTT and PMSF to the enzyme extract enhanced the hydantoinase activity but had no effect on the N-carbamoylase activity. The N-carbamoylase was unstable at 40°C and was almost completely inactivated after 24 hours incubation at this temperature. The hydantoinase and N-carbamoylase appeared to be insoluble. Various techniques were investigated for the solubilisation of the enzymes including various cell lysis methods, cell lysis at extremes of pH and ionic strength, addition of a reducing agent and protease inhibitors, and treatment with hydrolysing enzymes and detergents. Treatment with Triton X-100 was most effective for the solubilisation of the enzymes indicating that the enzymes were membrane-bound. Hydropathy and transmembrane prediction plots of the predicted amino acid sequences for two identified N-carbamoylase genes from A. tumefaciens RU-ORPN1 revealed possible transmembrane regions in the amino acid sequences, and thus supported the hypothesis that the enzymes were membrane-bound. Various methods were evaluated for the immobilisation of the enzymes in whole cells and enzyme extracts. Immobilisation of the enzyme extract in calcium alginate beads was found to be the best method in terms of enzyme activity retention and stability. The hydantoinase retained 55% activity while the N-carbamoylase exhibited a remarkable sevenfold increase in activity after immobilisation by this method. Furthermore, the hydantoinase activity increased after storage at 4°C for 21 days, while the N-carbamoylase retained 30% activity after this storage period. The calcium alginate bead-immobilised enzymes were further biochemically characterised and then applied in a bioreactor system for the production of D-hydroxyphenylglycine (D-HPG) from D,L-5-hydroxyphenylhydantoin (D,L-5-HPH). The pH and temperature optima for the immobilised hydantoinase were pH 7 and 50°C, respectively, while pH 8 and 40°C were optimal for the immobilised N-carbamoylase enzyme. The immobilised enzymes showed improved thermostability at 40°C in comparison to the free enzymes and retained high levels of activity after five repeated batch reactions. Low levels of conversion were obtained in a packed-bed bioreactor containing the A. tumefaciens RU-ORPN1 biocatalyst due to the low hydantoinase activity present in the strain, relative to N-carbamoylase. A novel, packed-bed bioreactor system was therefore developed for the production of D-HPG from D,L-5-HPH using the A. tumefaciens biocatalyst in combination with a Pseudomonas sp. biocatalyst having high hydantoinase activity. A conversion yield of 22 to 30% was achieved for the production of D-HPG from D,L-5-HPH over 5 days operation demonstrating that the hydantoin-hydrolysing enzymes from A. tumefaciens RU-ORPN1 could be stabilised by immobilisation and, in combination with a biocatalyst with high hydantoinase activity, could be applied to the fully enzymatic conversion of D,L-5-HPH to D-HPG.
- Full Text:
- Date Issued: 2004
- Authors: Foster, Ingrid Margaret
- Date: 2004
- Subjects: Agrobacterium tumefaciens Amino acids Hydantoin Hydrolysis Enzymes
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3943 , http://hdl.handle.net/10962/d1004002
- Description: A calcium alginate bead-immobilised biocatalyst was developed utilising the D-hydantoinase and D-N-carbamoylase from a novel, mutant Agrobacterium tumefaciens strain RU-ORPN1. The growth conditions for the inducer-independent strain were optimised for production of hydantoinase and N-carbamoylase activities. Methods for the preparation of crude enzyme extracts were evaluated in terms of hydantoinase and N-carbamoylase activities produced. After comparison of the enzyme activities and stabilities in various extracts from fresh and frozen cells, sonication of frozen cells for 5 minutes was found to be the best method for the production of the enzyme extract. The optimal pH and temperature for the hydantoinase activity were pH 10 and 30°C, respectively, while pH 9 and 40°C were optimal for Ncarbamoylase activity. The hydantoinase activity was enhanced by the addition of Mg^(2+) ions to the enzyme extract and the N-carbamoylase was enhanced by the addition of Mg^(2+), Mn^(2+) or Zn^(2+) ions to the enzyme extract. The enzyme activities increased in the presence of ATP suggesting that the enzymes may be ATP-dependent. The addition of DTT and PMSF to the enzyme extract enhanced the hydantoinase activity but had no effect on the N-carbamoylase activity. The N-carbamoylase was unstable at 40°C and was almost completely inactivated after 24 hours incubation at this temperature. The hydantoinase and N-carbamoylase appeared to be insoluble. Various techniques were investigated for the solubilisation of the enzymes including various cell lysis methods, cell lysis at extremes of pH and ionic strength, addition of a reducing agent and protease inhibitors, and treatment with hydrolysing enzymes and detergents. Treatment with Triton X-100 was most effective for the solubilisation of the enzymes indicating that the enzymes were membrane-bound. Hydropathy and transmembrane prediction plots of the predicted amino acid sequences for two identified N-carbamoylase genes from A. tumefaciens RU-ORPN1 revealed possible transmembrane regions in the amino acid sequences, and thus supported the hypothesis that the enzymes were membrane-bound. Various methods were evaluated for the immobilisation of the enzymes in whole cells and enzyme extracts. Immobilisation of the enzyme extract in calcium alginate beads was found to be the best method in terms of enzyme activity retention and stability. The hydantoinase retained 55% activity while the N-carbamoylase exhibited a remarkable sevenfold increase in activity after immobilisation by this method. Furthermore, the hydantoinase activity increased after storage at 4°C for 21 days, while the N-carbamoylase retained 30% activity after this storage period. The calcium alginate bead-immobilised enzymes were further biochemically characterised and then applied in a bioreactor system for the production of D-hydroxyphenylglycine (D-HPG) from D,L-5-hydroxyphenylhydantoin (D,L-5-HPH). The pH and temperature optima for the immobilised hydantoinase were pH 7 and 50°C, respectively, while pH 8 and 40°C were optimal for the immobilised N-carbamoylase enzyme. The immobilised enzymes showed improved thermostability at 40°C in comparison to the free enzymes and retained high levels of activity after five repeated batch reactions. Low levels of conversion were obtained in a packed-bed bioreactor containing the A. tumefaciens RU-ORPN1 biocatalyst due to the low hydantoinase activity present in the strain, relative to N-carbamoylase. A novel, packed-bed bioreactor system was therefore developed for the production of D-HPG from D,L-5-HPH using the A. tumefaciens biocatalyst in combination with a Pseudomonas sp. biocatalyst having high hydantoinase activity. A conversion yield of 22 to 30% was achieved for the production of D-HPG from D,L-5-HPH over 5 days operation demonstrating that the hydantoin-hydrolysing enzymes from A. tumefaciens RU-ORPN1 could be stabilised by immobilisation and, in combination with a biocatalyst with high hydantoinase activity, could be applied to the fully enzymatic conversion of D,L-5-HPH to D-HPG.
- Full Text:
- Date Issued: 2004
The doctrine of duress in the law of contract and unjustified enrichment in South Africa
- Authors: Glover, Graham Brian
- Date: 2004
- Subjects: Contracts -- South Africa , Duress (Law) -- South Africa , Remedies (Law) -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3672 , http://hdl.handle.net/10962/d1003187 , Contracts -- South Africa , Duress (Law) -- South Africa , Remedies (Law) -- South Africa
- Description: This thesis analyses the doctrine of duress and its application in the law of contract and unjustified enrichment in South Africa. Following an initial examination of the historical development of the doctrine from its roots in Roman and Roman-Dutch law, the study focuses on the current legal position in the two areas of law under review, identifies the substantive and formal deficiencies in the current approach, and suggests, using comparative authorities, how the law might be developed. As far as the law of contract is concerned, after exposing the difficulties inherent in the current approach, and placing the doctrine in its proper context in the South African law of contract generally, it is argued that the duress doctrine finds its juridical basis in the principle of good faith. A more modern and coherent test for duress is then proposed: one that concentrates on the question whether an illegitimate threat was made, which induced a contract in that it left the other person no reasonable choice but to succumb to the proposal. Additionally, the need for South African contract law to recognise and deal with cases of economic duress is emphasised. The study then shifts to an examination of the position in situations where non-contractual performances have occurred under duress: cases that are decided in terms of the principles of the law of unjustified enrichment. The current position is reviewed, and it is shown that the approach to duress cases is substantially different to the approach that applies in contract. An attempt is made to reconcile this problem. From a structural perspective, the nature and application of the relevant enrichment action where a non-contractual performance is made under duress (the condictio indebiti) is also investigated, in the light of approaches to enrichment adopted in both Germany and England, in an attempt to make better sense of this enrichment action in the South African context. The study closes with an analysis of the various contractual, delictual and enrichment remedies that are available once a case of duress has been proved.
- Full Text:
- Date Issued: 2004
- Authors: Glover, Graham Brian
- Date: 2004
- Subjects: Contracts -- South Africa , Duress (Law) -- South Africa , Remedies (Law) -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3672 , http://hdl.handle.net/10962/d1003187 , Contracts -- South Africa , Duress (Law) -- South Africa , Remedies (Law) -- South Africa
- Description: This thesis analyses the doctrine of duress and its application in the law of contract and unjustified enrichment in South Africa. Following an initial examination of the historical development of the doctrine from its roots in Roman and Roman-Dutch law, the study focuses on the current legal position in the two areas of law under review, identifies the substantive and formal deficiencies in the current approach, and suggests, using comparative authorities, how the law might be developed. As far as the law of contract is concerned, after exposing the difficulties inherent in the current approach, and placing the doctrine in its proper context in the South African law of contract generally, it is argued that the duress doctrine finds its juridical basis in the principle of good faith. A more modern and coherent test for duress is then proposed: one that concentrates on the question whether an illegitimate threat was made, which induced a contract in that it left the other person no reasonable choice but to succumb to the proposal. Additionally, the need for South African contract law to recognise and deal with cases of economic duress is emphasised. The study then shifts to an examination of the position in situations where non-contractual performances have occurred under duress: cases that are decided in terms of the principles of the law of unjustified enrichment. The current position is reviewed, and it is shown that the approach to duress cases is substantially different to the approach that applies in contract. An attempt is made to reconcile this problem. From a structural perspective, the nature and application of the relevant enrichment action where a non-contractual performance is made under duress (the condictio indebiti) is also investigated, in the light of approaches to enrichment adopted in both Germany and England, in an attempt to make better sense of this enrichment action in the South African context. The study closes with an analysis of the various contractual, delictual and enrichment remedies that are available once a case of duress has been proved.
- Full Text:
- Date Issued: 2004
Characterisation of the J domain aminoacid residues important for the interaction of DNAJ-like proteins with HSP70 chaperones
- Authors: Hennessy, Fritha
- Date: 2004
- Subjects: Heat shock proteins Protein folding Proteins -- Analysis Proteins -- Structure Molecular chaperones
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3937 , http://hdl.handle.net/10962/d1003996
- Description: The 70 kDa heat shock proteins (Hsp70s) are vital for normal protein folding, as they stabilise the unfolded state of nascent polypeptides, allowing these sufficient time to attain a correct tertiary structure. Hsp70s are aided by the DnaJ-like family of proteins, which interact with Hsp70s in order to enhance the chaperone activity of these proteins. DnaJ-like proteins contain a J domain, a seventy amino acid domain consisting of four α-helices, which is defined by the presence of an invariant tripeptide of histidine, proline and aspartic acid (HPD motif). This motif is key to the interaction between DnaJ-like proteins and Hsp70s. This thesis has focused on determining the presence of other conserved residues in the J domain and their role in mediating the interaction of DnaJ-like proteins with partner Hsp70s. DnaJ-like proteins from Agrobacterium tumefaciens RUOR were isolated and used as a model system. A. tumefaciens DnaJ (Agt DnaJ) was able to replace the lack of E. coli DnaJ in an E. coli null mutant strain, however, additional A. tumefaciens DnaJ-like proteins Agt DjC1/DjlA, Agt DjC2 and Agt DjC5 were unable to complement for the lack of E. coli DnaJ. Replacement of the Agt DnaJ J domain with J domains from these proteins resulted in non-functional chimeric proteins, despite some sequence conservation. The kinetics of the basal specific ATPase activity of Agt DnaK, and its ability to have this activity stimulated by Agt DnaJ and Agt DnaJ-H33Q were also investigated. Stimulation of the ATPase activity by Agt DnaJ ranged between 1.5 to 2 fold, but Agt DnaJ-H33Q was unable to stimulate the basal ATPase activity. Conserved amino acids in the J domain were identified in silico, and these residues were substituted in the J domain of Agt DnaJ. The ability of these derivative proteins to replace E. coli DnaJ was investigated. Alterations in the HPD motif gave rise to proteins unable to complement for lack of E. coli DnaJ, consistent with literature. Agt DnaJ-R26A was unable to replace E. coli DnaJ suggesting that Arg26 could be key to the interaction with partner Hsp70s. Agt DnaJ-D59A was unable to replace E. coli DnaJ; substitutions in Asp59 have not previously been shown to impact on the function of DnaJ. Substituting Arg63 in Agt DnaJ abrogated the levels of complementation. Substitution of several structural residues was also found to disrupt the in vivo function of Agt DnaJ suggesting that the maintenance of the structural integrity of the J domain was important for function. This study has identified a number of residues critical to the structure and function of the J domain of Agt DnaJ, and potentially of general importance as molecular determinants for DnaJ-Hsp70 interaction.
- Full Text:
- Date Issued: 2004
- Authors: Hennessy, Fritha
- Date: 2004
- Subjects: Heat shock proteins Protein folding Proteins -- Analysis Proteins -- Structure Molecular chaperones
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3937 , http://hdl.handle.net/10962/d1003996
- Description: The 70 kDa heat shock proteins (Hsp70s) are vital for normal protein folding, as they stabilise the unfolded state of nascent polypeptides, allowing these sufficient time to attain a correct tertiary structure. Hsp70s are aided by the DnaJ-like family of proteins, which interact with Hsp70s in order to enhance the chaperone activity of these proteins. DnaJ-like proteins contain a J domain, a seventy amino acid domain consisting of four α-helices, which is defined by the presence of an invariant tripeptide of histidine, proline and aspartic acid (HPD motif). This motif is key to the interaction between DnaJ-like proteins and Hsp70s. This thesis has focused on determining the presence of other conserved residues in the J domain and their role in mediating the interaction of DnaJ-like proteins with partner Hsp70s. DnaJ-like proteins from Agrobacterium tumefaciens RUOR were isolated and used as a model system. A. tumefaciens DnaJ (Agt DnaJ) was able to replace the lack of E. coli DnaJ in an E. coli null mutant strain, however, additional A. tumefaciens DnaJ-like proteins Agt DjC1/DjlA, Agt DjC2 and Agt DjC5 were unable to complement for the lack of E. coli DnaJ. Replacement of the Agt DnaJ J domain with J domains from these proteins resulted in non-functional chimeric proteins, despite some sequence conservation. The kinetics of the basal specific ATPase activity of Agt DnaK, and its ability to have this activity stimulated by Agt DnaJ and Agt DnaJ-H33Q were also investigated. Stimulation of the ATPase activity by Agt DnaJ ranged between 1.5 to 2 fold, but Agt DnaJ-H33Q was unable to stimulate the basal ATPase activity. Conserved amino acids in the J domain were identified in silico, and these residues were substituted in the J domain of Agt DnaJ. The ability of these derivative proteins to replace E. coli DnaJ was investigated. Alterations in the HPD motif gave rise to proteins unable to complement for lack of E. coli DnaJ, consistent with literature. Agt DnaJ-R26A was unable to replace E. coli DnaJ suggesting that Arg26 could be key to the interaction with partner Hsp70s. Agt DnaJ-D59A was unable to replace E. coli DnaJ; substitutions in Asp59 have not previously been shown to impact on the function of DnaJ. Substituting Arg63 in Agt DnaJ abrogated the levels of complementation. Substitution of several structural residues was also found to disrupt the in vivo function of Agt DnaJ suggesting that the maintenance of the structural integrity of the J domain was important for function. This study has identified a number of residues critical to the structure and function of the J domain of Agt DnaJ, and potentially of general importance as molecular determinants for DnaJ-Hsp70 interaction.
- Full Text:
- Date Issued: 2004
Journeys of the learning soul: Plato to Descartes
- Authors: Hugo, Wayne
- Date: 2004
- Subjects: Education -- Philosophy Education -- History Education, Ancient Education, Greek
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1884 , http://hdl.handle.net/10962/d1005917
- Description: This thesis aims to build up a picture of what it has meant for us within the western canon to educate a human being through the depths and heights of existence. It uses narrative accounts of educational journeys from ancient, medieval and early modern sources to develop an integral picture of the spectrum of education along with the techniques and fore-structures needed to guide a student through the various stages and encounters. Key metaphors, journeys and relationships - Diotirna's ladder of beauty, Plato's cave, Philo's Abraham and Sarah, Origen's bride and Bridegroom, Plotinus' journey of the alone to the Alone, Augustine's Confessions, the tragic love of Abelard and Heloise, Dante's encounters in the infernal, purgatorial and paradisical realms of human experience, Shakespeare's great playing within the same realm, and Descartes' doubting genius provide a rich ensemble, each resonating with the next, opening out intellectual, affective, volitional, and imaginative paths through the full terrain of human existence. This multidimensional approach points towards a flexible and insightful pedagogics that works with the enormous variety and capacity of human learning rather than heavy-handedly insisting on one path, or, even worse, not recognizing and dealing with specific areas of human living that occur in the upper and lower reaches of our educational endeavours. Phenomenological, Hermeneutic and Integral methods suggested by Heidegger and Wilber amongst others were used to inform the process of research. The results of this thesis are not contained in its reconunendations but in the effects of its reading. It is itself a tool that embodies and encourages the principles of an educational tradition that has existed within the history of western learning, not seeking a return to ancient or medieval ways but to provide a backlight that assists current initiatives working with the full range of human potential.
- Full Text:
- Date Issued: 2004
- Authors: Hugo, Wayne
- Date: 2004
- Subjects: Education -- Philosophy Education -- History Education, Ancient Education, Greek
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1884 , http://hdl.handle.net/10962/d1005917
- Description: This thesis aims to build up a picture of what it has meant for us within the western canon to educate a human being through the depths and heights of existence. It uses narrative accounts of educational journeys from ancient, medieval and early modern sources to develop an integral picture of the spectrum of education along with the techniques and fore-structures needed to guide a student through the various stages and encounters. Key metaphors, journeys and relationships - Diotirna's ladder of beauty, Plato's cave, Philo's Abraham and Sarah, Origen's bride and Bridegroom, Plotinus' journey of the alone to the Alone, Augustine's Confessions, the tragic love of Abelard and Heloise, Dante's encounters in the infernal, purgatorial and paradisical realms of human experience, Shakespeare's great playing within the same realm, and Descartes' doubting genius provide a rich ensemble, each resonating with the next, opening out intellectual, affective, volitional, and imaginative paths through the full terrain of human existence. This multidimensional approach points towards a flexible and insightful pedagogics that works with the enormous variety and capacity of human learning rather than heavy-handedly insisting on one path, or, even worse, not recognizing and dealing with specific areas of human living that occur in the upper and lower reaches of our educational endeavours. Phenomenological, Hermeneutic and Integral methods suggested by Heidegger and Wilber amongst others were used to inform the process of research. The results of this thesis are not contained in its reconunendations but in the effects of its reading. It is itself a tool that embodies and encourages the principles of an educational tradition that has existed within the history of western learning, not seeking a return to ancient or medieval ways but to provide a backlight that assists current initiatives working with the full range of human potential.
- Full Text:
- Date Issued: 2004
A phenological and bioclimatic analysis of honey yield in South Africa
- Authors: Illgner, Peter Mark
- Date: 2004
- Subjects: Bee culture -- South Africa -- Statistics Honeybee -- South Africa Bee culture -- South Africa -- Management Honey plants -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5813 , http://hdl.handle.net/10962/d1007153
- Description: This study has investigated the interaction between honeybees and their forage plants and the impact of selected climatic variables on honey production in South Africa. Twenty-seven scale-hive records from 25 localities have been used as a measure of colony honey reserves. At least 944 plant species are visited by honeybees in South Africa for their nectar and/or pollen, with more than half providing both rewards. The entire honeybee flora encompasses 532 genera and 137 families. The flowering phenologies of the different reward categories of the indigenous forage plants are all significantly and positively correlated at the 0.05 level. Similarly, species offering both rewards are significantly and positively correlated with the flowering phenology of the null flora. The same results were obtained for correlations between the different reward categories of the exotic forage plants in South Africa. Of the 30 species pairs which fulfilled the criteria for selection, 23 occurred in sympatry, 5 in allopatry and 2 in possible parapatry. There is evidence for both competition and facilitation within different indigenous species pairs. The lack of geographical correlation in the intra-annual variation in honey stores and the near absence of any statistically significant (p < 0.05) honey related intra-annual intracolonial correlations may indicate that the former is more important than the latter for the determination of the level of honey reserves within a colony. Only one statistically significant correlation was found between either scale-hive record from the University of Pretoria Experimental Farm and any of the selected climatic variables. A one month lag period and/or possible seasonal effects were detected for each variable, with the exception of the duration of sunshine, in the autocorrelation analyses. A possible 12 month seasonal period was also identified in the single series fourier analyses for a number of variables. Similarly, 12 months was also the most frequently recurring period in the crossspectral results for the one scale-hive record (H42). Any activities which have an impact on the landscape have the potential to affect honeybees and/or their forage plants. Honeybee crop or plant pollination may also enhance yields for commercial farmers and facilitate rural food security.
- Full Text:
- Date Issued: 2004
- Authors: Illgner, Peter Mark
- Date: 2004
- Subjects: Bee culture -- South Africa -- Statistics Honeybee -- South Africa Bee culture -- South Africa -- Management Honey plants -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5813 , http://hdl.handle.net/10962/d1007153
- Description: This study has investigated the interaction between honeybees and their forage plants and the impact of selected climatic variables on honey production in South Africa. Twenty-seven scale-hive records from 25 localities have been used as a measure of colony honey reserves. At least 944 plant species are visited by honeybees in South Africa for their nectar and/or pollen, with more than half providing both rewards. The entire honeybee flora encompasses 532 genera and 137 families. The flowering phenologies of the different reward categories of the indigenous forage plants are all significantly and positively correlated at the 0.05 level. Similarly, species offering both rewards are significantly and positively correlated with the flowering phenology of the null flora. The same results were obtained for correlations between the different reward categories of the exotic forage plants in South Africa. Of the 30 species pairs which fulfilled the criteria for selection, 23 occurred in sympatry, 5 in allopatry and 2 in possible parapatry. There is evidence for both competition and facilitation within different indigenous species pairs. The lack of geographical correlation in the intra-annual variation in honey stores and the near absence of any statistically significant (p < 0.05) honey related intra-annual intracolonial correlations may indicate that the former is more important than the latter for the determination of the level of honey reserves within a colony. Only one statistically significant correlation was found between either scale-hive record from the University of Pretoria Experimental Farm and any of the selected climatic variables. A one month lag period and/or possible seasonal effects were detected for each variable, with the exception of the duration of sunshine, in the autocorrelation analyses. A possible 12 month seasonal period was also identified in the single series fourier analyses for a number of variables. Similarly, 12 months was also the most frequently recurring period in the crossspectral results for the one scale-hive record (H42). Any activities which have an impact on the landscape have the potential to affect honeybees and/or their forage plants. Honeybee crop or plant pollination may also enhance yields for commercial farmers and facilitate rural food security.
- Full Text:
- Date Issued: 2004
Factors affecting the invasion of Pteronia incana (Blue bush) onto hillslopes in Ngqushwa (formerly Peddie) District, Eastern Cape
- Authors: Kakembo, Vincent
- Date: 2004
- Subjects: Shrubs -- South Africa -- Eastern Cape Slopes (Physical geography) -- South Africa -- Eastern Cape Biological invasions -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4833 , http://hdl.handle.net/10962/d1005508
- Description: The factors that influence the invasion of hillslopes by the shrub Pteronia incana in the communal rangelands of Ngqushwa (formerly Peddie) district were investigated. Mgwalana, one of the catchments in the district where encroachment by the species is widespread, was chosen. The study combined field observations with image analysis based on high resolution infrared imagery. The catchment was flown and high resolution infrared images (1mx1m) were taken using a Kodak DCS420 digital, colour-infrared camera. The images were analysed using Idrisi32 and Kilimanjaro GIS versions. The ability of different vegetation indices to separate P. incana from the other cover types was investigated. Field observations of the degree of P. incana invasion in relation to, inter alia, soil surface conditions, slope angle and visible forms of erosion were made. A Digital Elevation Model (DEM) of 20m spatial resolution was used to derive terrain parameters. The presence and absence of P. incana in relation to slope gradient and aspect were determined. The combined influence of the two terrain parameters and land use on the invasion was also investigated. The Topographic Wetness Index (WI), a component of the TOPMODEL was derived from the DEM and its relationship with the spatial distribution of P. incana was explored. Soil moisture dependencies for P. incana and grass species as well as surrogates for runoff under the shrub and adjacent bare areas were determined in the field. A high level of classification accuracy confirmed the reliability of digital camera imagery for spatial analyses. Distinct spectral separability for the surface vegetation cover types was achieved by means of the Perpendicular Vegetation Index (PVI) as opposed to the ratio based vegetation indices (NDVI, SAVI and MSAVI). The absence/presence of P. incana was noted to be strongly influenced by slope angle and aspect. The probability for P. incana occurrence increased with slope steepness and southerly slope orientation. Abandoned and grazing lands were identified as the main invasion hotspots. Blanket invasion of the former signified the high susceptibility of abandoned land to P. incana invasion. The combined influence of land use, slope gradient and aspect was also noted to have promoted the invasion. This is borne out by the concentration of the invasion on abandoned steep slopes with a southerly orientation. Local topographic variations were identified as having a strong bearing on P. incana spatial distribution. The topographically driven WI confirmed this relationship, such that P. incana was associated with the low WI values of convexities. Differences in the moisture dependencies between P. incana and grass species were demonstrated by the greater rooting depth of the former. During field surveys, soil surface crusting was noted as inherent to P. incana patchiness. The coupling between local topography and soil surface crusting underpins soil moisture variability at hillslope and patch scales respectively. This in turn determines the competition between P. incana and grass species and the eventual replacement of the latter by the former. A close spatial correlation between fully established P. incana and severe forms of soil erosion was observed. Loss of patchiness and expansion of inter-patch bare areas promote runoff connectivity erosion. As most of the runoff becomes run out, hillslopes tend towards dysfunctional systems. Greater soil moisture storage after rainstorms under P. incana tussocks than the adjacent bare areas signifies the shrub’s water harvesting capabilities. The tussocks could thus serve as a starting-pointbuilding- block for the rehabilitation of dysfunctional hillslope systems.
- Full Text:
- Date Issued: 2004
- Authors: Kakembo, Vincent
- Date: 2004
- Subjects: Shrubs -- South Africa -- Eastern Cape Slopes (Physical geography) -- South Africa -- Eastern Cape Biological invasions -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4833 , http://hdl.handle.net/10962/d1005508
- Description: The factors that influence the invasion of hillslopes by the shrub Pteronia incana in the communal rangelands of Ngqushwa (formerly Peddie) district were investigated. Mgwalana, one of the catchments in the district where encroachment by the species is widespread, was chosen. The study combined field observations with image analysis based on high resolution infrared imagery. The catchment was flown and high resolution infrared images (1mx1m) were taken using a Kodak DCS420 digital, colour-infrared camera. The images were analysed using Idrisi32 and Kilimanjaro GIS versions. The ability of different vegetation indices to separate P. incana from the other cover types was investigated. Field observations of the degree of P. incana invasion in relation to, inter alia, soil surface conditions, slope angle and visible forms of erosion were made. A Digital Elevation Model (DEM) of 20m spatial resolution was used to derive terrain parameters. The presence and absence of P. incana in relation to slope gradient and aspect were determined. The combined influence of the two terrain parameters and land use on the invasion was also investigated. The Topographic Wetness Index (WI), a component of the TOPMODEL was derived from the DEM and its relationship with the spatial distribution of P. incana was explored. Soil moisture dependencies for P. incana and grass species as well as surrogates for runoff under the shrub and adjacent bare areas were determined in the field. A high level of classification accuracy confirmed the reliability of digital camera imagery for spatial analyses. Distinct spectral separability for the surface vegetation cover types was achieved by means of the Perpendicular Vegetation Index (PVI) as opposed to the ratio based vegetation indices (NDVI, SAVI and MSAVI). The absence/presence of P. incana was noted to be strongly influenced by slope angle and aspect. The probability for P. incana occurrence increased with slope steepness and southerly slope orientation. Abandoned and grazing lands were identified as the main invasion hotspots. Blanket invasion of the former signified the high susceptibility of abandoned land to P. incana invasion. The combined influence of land use, slope gradient and aspect was also noted to have promoted the invasion. This is borne out by the concentration of the invasion on abandoned steep slopes with a southerly orientation. Local topographic variations were identified as having a strong bearing on P. incana spatial distribution. The topographically driven WI confirmed this relationship, such that P. incana was associated with the low WI values of convexities. Differences in the moisture dependencies between P. incana and grass species were demonstrated by the greater rooting depth of the former. During field surveys, soil surface crusting was noted as inherent to P. incana patchiness. The coupling between local topography and soil surface crusting underpins soil moisture variability at hillslope and patch scales respectively. This in turn determines the competition between P. incana and grass species and the eventual replacement of the latter by the former. A close spatial correlation between fully established P. incana and severe forms of soil erosion was observed. Loss of patchiness and expansion of inter-patch bare areas promote runoff connectivity erosion. As most of the runoff becomes run out, hillslopes tend towards dysfunctional systems. Greater soil moisture storage after rainstorms under P. incana tussocks than the adjacent bare areas signifies the shrub’s water harvesting capabilities. The tussocks could thus serve as a starting-pointbuilding- block for the rehabilitation of dysfunctional hillslope systems.
- Full Text:
- Date Issued: 2004
An investigation into how marketers cope with an environment of high complexity and turbulence, with special reference to the South African environment
- Authors: Mason, Roger Bruce
- Date: 2004
- Subjects: Marketing -- South Africa , Success in business -- South Africa , Industrial management -- South Africa , Organizational change -- South Africa , Chaotic behavior in systems , Complexity (Philosophy)
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:752 , http://hdl.handle.net/10962/d1003873 , Marketing -- South Africa , Success in business -- South Africa , Industrial management -- South Africa , Organizational change -- South Africa , Chaotic behavior in systems , Complexity (Philosophy)
- Description: This study investigated relationships between marketing success, the level of external environmental complexity and turbulence, and marketing mix tactics. The literature suggested that more successful companies in simple and stable environments use stabilising marketing tactics, while more successful companies in complex and turbulent environments use destabilising tactics, regardless of industry habits, management preferences or market sector. A marketing mix model for the different environments was developed using a chaos and complexity theory perspective. The study was exploratory, using a qualitative, case study technique. Data was collected via depth interviews and document analysis from four companies in the information technology (IT) and packaging industries. These industries were identified as, respectively, the most complex and turbulent, and the simplest and most stable, South African environments. Two companies from each industry were chosen to reflect more successful and less successful companies. The more successful company in the complex/turbulent environment was found to use destabilising tactics, as did the more successful company in the simple/stable environment. Therefore, contrary to expectations, it appears that destabilising tactics contribute more to success than stabilising tactics do, regardless of the environment. It was also found, contrary to expectations, that stabilising tactics were used by both the less successful companies. The research concluded that destabilising tactics are related to more success and stabilising tactics to less success. The lack of clear differentiation between the two industries may be because the whole South African environment is complex and turbulent, because the packaging industry is not sufficiently simple and stable to differentiate it from the IT industry or because packaging industry managers perceive their industry to be complex and turbulent and act accordingly. Despite these uncertainties, the research showed the marketing mix model to be reasonably accurate for the complex/turbulent environment, and therefore of potential value to South African companies. To overcome the equivocal findings, further research is recommended in different industries, in countries with different levels of complexity and turbulence and into specific marketing mix tactics. Research into managers’ perceptions of environmental complexity and turbulence and into co-evolution of marketing tactics and external environments would also be of value.
- Full Text:
- Date Issued: 2004
- Authors: Mason, Roger Bruce
- Date: 2004
- Subjects: Marketing -- South Africa , Success in business -- South Africa , Industrial management -- South Africa , Organizational change -- South Africa , Chaotic behavior in systems , Complexity (Philosophy)
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:752 , http://hdl.handle.net/10962/d1003873 , Marketing -- South Africa , Success in business -- South Africa , Industrial management -- South Africa , Organizational change -- South Africa , Chaotic behavior in systems , Complexity (Philosophy)
- Description: This study investigated relationships between marketing success, the level of external environmental complexity and turbulence, and marketing mix tactics. The literature suggested that more successful companies in simple and stable environments use stabilising marketing tactics, while more successful companies in complex and turbulent environments use destabilising tactics, regardless of industry habits, management preferences or market sector. A marketing mix model for the different environments was developed using a chaos and complexity theory perspective. The study was exploratory, using a qualitative, case study technique. Data was collected via depth interviews and document analysis from four companies in the information technology (IT) and packaging industries. These industries were identified as, respectively, the most complex and turbulent, and the simplest and most stable, South African environments. Two companies from each industry were chosen to reflect more successful and less successful companies. The more successful company in the complex/turbulent environment was found to use destabilising tactics, as did the more successful company in the simple/stable environment. Therefore, contrary to expectations, it appears that destabilising tactics contribute more to success than stabilising tactics do, regardless of the environment. It was also found, contrary to expectations, that stabilising tactics were used by both the less successful companies. The research concluded that destabilising tactics are related to more success and stabilising tactics to less success. The lack of clear differentiation between the two industries may be because the whole South African environment is complex and turbulent, because the packaging industry is not sufficiently simple and stable to differentiate it from the IT industry or because packaging industry managers perceive their industry to be complex and turbulent and act accordingly. Despite these uncertainties, the research showed the marketing mix model to be reasonably accurate for the complex/turbulent environment, and therefore of potential value to South African companies. To overcome the equivocal findings, further research is recommended in different industries, in countries with different levels of complexity and turbulence and into specific marketing mix tactics. Research into managers’ perceptions of environmental complexity and turbulence and into co-evolution of marketing tactics and external environments would also be of value.
- Full Text:
- Date Issued: 2004
A critical investigation into discourses that construct academic literacy at the Durban Institute of Technology
- Authors: McKenna, Sioux
- Date: 2004
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1317 , http://hdl.handle.net/10962/d1004121
- Description: This thesis examines the construction of academic literacy at the Durban Institute of Technology through a discourse analysis of interviews with educators and learners. Academic literacy comprises the norms and values of higher education as manifested in discipline-specific practices. Students are expected to take on these practices, and the underlying epistemologies, without any overt instruction in, or critique of, these ways of being. Lecturer and student discourses are identified and discussed in terms of their impact on the teaching and learning process. This broad context of educator and student understandings is set against the backdrop of the changing educational policies and structures in post-Apartheid South Africa. The changes in approach to academic development are also traced as a setting for the institutional study. The discourses about the intersection between language and learning were found largely to assume that texts, be they lectures, books, assignments etc, are neutral and autonomous of their contexts. Difficulties some learners experience in accessing or producing the expected meaning of these texts were largely ascribed to their problems with language at a surface level rather than to their lack of shared norms regarding the construction of these texts. The study provides an analysis of how the ‘autonomous’ model is manifested iii and illustrates the limitations on curriculum change imposed by this understanding of how texts are constructed and interpreted. Discourses of motivation presume that students’ difficulties in taking on the literacy practices esteemed by the academy are related to attitude. This discourse assumes that learners have a fairly fixed identity, an assumption that did not bear out in the data. The multiple identities of the learners often presented tensions in the acquisition of discipline-specific academic literacies. The learners were found not to invest strongly in an academically literate identity, or were found to experience conflict between this target identity and the identities they brought with them to the institution. The elevation of academic literacy practices is questioned if the surface features, characteristic of these practices, are valued without a concomitant claim to knowledge production. The rapid emergence of a high skills discourse in Universities of Technology in South Africa is also interrogated, given the current emphasis on training for economic growth over discourses of social redress and transformation.
- Full Text:
- Date Issued: 2004
- Authors: McKenna, Sioux
- Date: 2004
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1317 , http://hdl.handle.net/10962/d1004121
- Description: This thesis examines the construction of academic literacy at the Durban Institute of Technology through a discourse analysis of interviews with educators and learners. Academic literacy comprises the norms and values of higher education as manifested in discipline-specific practices. Students are expected to take on these practices, and the underlying epistemologies, without any overt instruction in, or critique of, these ways of being. Lecturer and student discourses are identified and discussed in terms of their impact on the teaching and learning process. This broad context of educator and student understandings is set against the backdrop of the changing educational policies and structures in post-Apartheid South Africa. The changes in approach to academic development are also traced as a setting for the institutional study. The discourses about the intersection between language and learning were found largely to assume that texts, be they lectures, books, assignments etc, are neutral and autonomous of their contexts. Difficulties some learners experience in accessing or producing the expected meaning of these texts were largely ascribed to their problems with language at a surface level rather than to their lack of shared norms regarding the construction of these texts. The study provides an analysis of how the ‘autonomous’ model is manifested iii and illustrates the limitations on curriculum change imposed by this understanding of how texts are constructed and interpreted. Discourses of motivation presume that students’ difficulties in taking on the literacy practices esteemed by the academy are related to attitude. This discourse assumes that learners have a fairly fixed identity, an assumption that did not bear out in the data. The multiple identities of the learners often presented tensions in the acquisition of discipline-specific academic literacies. The learners were found not to invest strongly in an academically literate identity, or were found to experience conflict between this target identity and the identities they brought with them to the institution. The elevation of academic literacy practices is questioned if the surface features, characteristic of these practices, are valued without a concomitant claim to knowledge production. The rapid emergence of a high skills discourse in Universities of Technology in South Africa is also interrogated, given the current emphasis on training for economic growth over discourses of social redress and transformation.
- Full Text:
- Date Issued: 2004
A phenomenological hermeneutic investigation into the psychoanalytic psychotherapist's experience of using the psychoanalytic couch
- Authors: Milton, Christopher
- Date: 2004
- Subjects: Freud, Sigmund, 1856-1939 -- Criticism and interpretation Psychoanalysis Psychotherapy Psychotherapy -- Methods
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3162 , http://hdl.handle.net/10962/d1007655
- Description: The aim of this study was to describe and critically explore the psychoanalytic, psychotherapist's lived experience of the technique of using the couch. Through examination of the literature a question was formulated that would disclose the analyst's experience of the technique of using the couch. Four experienced psychoanalytic practitioners who could be operationally defined as 'analysts' were interviewed. Using a phenomenological method the protocols were comprehensively analyzed to produce descriptions of the general structure of the experience. These were then texturally enhanced using interleaved direct citations from the interviews. The structural and textural 'findings ' so produced were then hermeneutically dialogued with contemporary psychoanalytic notions of critical discourse and intersubjectivity. The phenomenological ' findings ' of the study disclosed the meaning of the couch as context-based, paradoxical and ambiguous. The couch was found to be a symbol of the analyst as analyst and the process as authentic analysis. Furthermore, at its best, the couch was found to mediate a mode of being that is containing and intimate and in which psychological life may be evoked, tracked and interpreted. The most significant contributor to this mode of being was found to be privacy, which, in particular, helps the analyst maintain an analytic attitude. The couch was also found to be significantly implicated in the generation of an intersubjective analytic third and to support reverie. These 'findings' were hermeneutically dialogued with literature on the couch as well as contemporary psychoanalytic theoretical notions. The dialogue fell into three foci. The first focus entailed deconstructing the meaning of the couch as context-based and ambiguous and not essential. The second pursued critiques of the role that the couch plays in domination, of its function as a symbol/evocative object and of the way in which it shapes being-together, bodily attunement, privacy, the intersubjective analytic third and reverie. Finally the 'findings' were critically examined in terms of both Lacan's notion 'analytic discourse ' and its role in revealing/concealing the analysand as subject. The study concludes with an examination of its own limitations and suggestions for further research.
- Full Text:
- Date Issued: 2004
- Authors: Milton, Christopher
- Date: 2004
- Subjects: Freud, Sigmund, 1856-1939 -- Criticism and interpretation Psychoanalysis Psychotherapy Psychotherapy -- Methods
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3162 , http://hdl.handle.net/10962/d1007655
- Description: The aim of this study was to describe and critically explore the psychoanalytic, psychotherapist's lived experience of the technique of using the couch. Through examination of the literature a question was formulated that would disclose the analyst's experience of the technique of using the couch. Four experienced psychoanalytic practitioners who could be operationally defined as 'analysts' were interviewed. Using a phenomenological method the protocols were comprehensively analyzed to produce descriptions of the general structure of the experience. These were then texturally enhanced using interleaved direct citations from the interviews. The structural and textural 'findings ' so produced were then hermeneutically dialogued with contemporary psychoanalytic notions of critical discourse and intersubjectivity. The phenomenological ' findings ' of the study disclosed the meaning of the couch as context-based, paradoxical and ambiguous. The couch was found to be a symbol of the analyst as analyst and the process as authentic analysis. Furthermore, at its best, the couch was found to mediate a mode of being that is containing and intimate and in which psychological life may be evoked, tracked and interpreted. The most significant contributor to this mode of being was found to be privacy, which, in particular, helps the analyst maintain an analytic attitude. The couch was also found to be significantly implicated in the generation of an intersubjective analytic third and to support reverie. These 'findings' were hermeneutically dialogued with literature on the couch as well as contemporary psychoanalytic theoretical notions. The dialogue fell into three foci. The first focus entailed deconstructing the meaning of the couch as context-based and ambiguous and not essential. The second pursued critiques of the role that the couch plays in domination, of its function as a symbol/evocative object and of the way in which it shapes being-together, bodily attunement, privacy, the intersubjective analytic third and reverie. Finally the 'findings' were critically examined in terms of both Lacan's notion 'analytic discourse ' and its role in revealing/concealing the analysand as subject. The study concludes with an examination of its own limitations and suggestions for further research.
- Full Text:
- Date Issued: 2004
An exploration of teacher perceptions and actions to conserve wetlands in Kenya
- Authors: Ndaruga, Ayub Macharia
- Date: 2004
- Subjects: Wetlands -- Kenya Wetland conservation -- Kenya Wetland conservation -- Kenya -- Study and teaching ( Elementary) Wetlands -- Kenya -- Study and teaching (Elementary) Environmental education -- Kenya Sustainable development -- Study and teaching (Elementary) -- Kenya
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1535 , http://hdl.handle.net/10962/d1003417
- Description: This thesis presents the findings of an exploration of teacher perceptions and actions to conserve wetlands in Kenya. It reports findings of a case study survey done with 54 primary school teachers from seven of eight Kenyan provinces. The teachers were sampled from a larger group of 242 teachers who participated in an in-service course on wetlands conservation. The in-service course engaged teachers in exploring various aspects of wetlands and how they could enhance their conservation using both formal and non-formal contexts. The survey approach was used in the research and was augmented with a reflective process. Survey tools used were the questionnaires and interviews. The reflective process entailed observation, document analysis, field notes and the researcher’s diary. Research data was analysed in several stages. The study revealed that teachers were users of local wetlands just like other members of their communities. The teachers differed among themselves with respect to their perceptions of the value and threats to their local wetlands. The teachers also differed in their perceptions of community awareness of their local wetlands. The teachers’ perceptions about environmental education and wetlands were not holistic. The teachers recorded various opportunities to foster wetlands conservation in their local contexts at school and the community. These were their fellow teachers, the pupils, the subjects taught, clubs, environmental days and the community. The relative importance of these opportunities differed among the teachers. Many teachers claimed being motivated to promote wetlands conservation using both formal and non-formal contexts. Their motivation was based on diverse aspects of wetlands, education and the in-service training they attended in 1999. However, the intensity of motivation differed for each aspect. For instance, at community level in-service training was a major motivator while the curriculum aspects were not mentioned at all. Teachers reported having involved their pupils and the community in several activities to conserve the local wetlands. These activities seemed to be dominated by theoretical approaches, eco-management activities and visits to wetlands. There was little evidence to indicate the teachers being engaged in addressing the implications for sustainability of the perceived local wetland values and threats. The activities reported also failed to show engagement with local environmental problems as a deliberate proactive process involving exploration, discussion, action taking and reflection. Most of the activities were presented as one off activities rather than as a cyclic continuously improving series of interventions. The overall scenario presented by the teachers is one of inadequacy in addressing the sustainable use of wetlands. Teachers suggested various constraints that affect their realisation of environmental education for wetlands sustainability. The constraints traverse various aspects of the economic, biophysical, political, educational and social aspects of wetlands conservation. The study suggested the need for teachers to treat their contextual and personal conceptions as problematic rather than as simplistic or linear issues and to formulate ways to address them. This study suggests a potential but under-utilised opportunity to promote wetlands sustainability. The overall picture generated by the data in this study is a need to consider wetland training for teachers that integrates the holistic aspects of wetlands as well as the environmental education for sustainability perspectives grounded in local contexts.
- Full Text:
- Date Issued: 2004
- Authors: Ndaruga, Ayub Macharia
- Date: 2004
- Subjects: Wetlands -- Kenya Wetland conservation -- Kenya Wetland conservation -- Kenya -- Study and teaching ( Elementary) Wetlands -- Kenya -- Study and teaching (Elementary) Environmental education -- Kenya Sustainable development -- Study and teaching (Elementary) -- Kenya
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1535 , http://hdl.handle.net/10962/d1003417
- Description: This thesis presents the findings of an exploration of teacher perceptions and actions to conserve wetlands in Kenya. It reports findings of a case study survey done with 54 primary school teachers from seven of eight Kenyan provinces. The teachers were sampled from a larger group of 242 teachers who participated in an in-service course on wetlands conservation. The in-service course engaged teachers in exploring various aspects of wetlands and how they could enhance their conservation using both formal and non-formal contexts. The survey approach was used in the research and was augmented with a reflective process. Survey tools used were the questionnaires and interviews. The reflective process entailed observation, document analysis, field notes and the researcher’s diary. Research data was analysed in several stages. The study revealed that teachers were users of local wetlands just like other members of their communities. The teachers differed among themselves with respect to their perceptions of the value and threats to their local wetlands. The teachers also differed in their perceptions of community awareness of their local wetlands. The teachers’ perceptions about environmental education and wetlands were not holistic. The teachers recorded various opportunities to foster wetlands conservation in their local contexts at school and the community. These were their fellow teachers, the pupils, the subjects taught, clubs, environmental days and the community. The relative importance of these opportunities differed among the teachers. Many teachers claimed being motivated to promote wetlands conservation using both formal and non-formal contexts. Their motivation was based on diverse aspects of wetlands, education and the in-service training they attended in 1999. However, the intensity of motivation differed for each aspect. For instance, at community level in-service training was a major motivator while the curriculum aspects were not mentioned at all. Teachers reported having involved their pupils and the community in several activities to conserve the local wetlands. These activities seemed to be dominated by theoretical approaches, eco-management activities and visits to wetlands. There was little evidence to indicate the teachers being engaged in addressing the implications for sustainability of the perceived local wetland values and threats. The activities reported also failed to show engagement with local environmental problems as a deliberate proactive process involving exploration, discussion, action taking and reflection. Most of the activities were presented as one off activities rather than as a cyclic continuously improving series of interventions. The overall scenario presented by the teachers is one of inadequacy in addressing the sustainable use of wetlands. Teachers suggested various constraints that affect their realisation of environmental education for wetlands sustainability. The constraints traverse various aspects of the economic, biophysical, political, educational and social aspects of wetlands conservation. The study suggested the need for teachers to treat their contextual and personal conceptions as problematic rather than as simplistic or linear issues and to formulate ways to address them. This study suggests a potential but under-utilised opportunity to promote wetlands sustainability. The overall picture generated by the data in this study is a need to consider wetland training for teachers that integrates the holistic aspects of wetlands as well as the environmental education for sustainability perspectives grounded in local contexts.
- Full Text:
- Date Issued: 2004