Early stage ichthyofauna from shallow water habitats of the Angola-Benguela frontal zone
- Authors: Farthing, Matthew William
- Date: 2017
- Subjects: Fishes -- Larvae -- South Africa -- Atlantic coast , Fishes -- Larvae -- Angola -- Atlantic coast , Striped mullet -- Angola -- Atlantic coast
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/50442 , vital:25988
- Description: Early stage fishes (larvae and early juveniles) were collected from an array of shallow water (±1.5m) habitats on the warm-temperate southern Angolan coastline between June 2014 and June 2015. This study, the first assessment of the early stages of coastal fishes in Angola, provides important new understanding of non-estuarine shallow water nursery habitat use by coastal fishes from the region. In total, 51 species from 18 teleost families were observed. The exposed surf zone was dominated by postflexion larvae, while the moderately exposed beach and sheltered bay were dominated by early juveniles. Both fish density and diversity peaked in the wet season (Feb – Apr 2015) for all habitats, attributed to the influx of summer spawning species. Diplodus sargus dominated catches from the exposed surf zone, and the timing of observations supports the growing consensus that sparid spawning is dictated by temperature, not season. The similitude of the observed species to those observed in warm temperate South Africa highlights the historical connection of the warm-temperate study area with warm-temperate South Africa, prior to the formation of the Benguela Current as a vicariant barrier. The classification of the study assemblage into established estuarine utilization categories showed that the surf zone hosted more exclusively marine species than comparable surf zones in South Africa, attributed to the absence of estuaries in southern Angola. However, the observation of the marine estuarine dependent Mugil cephalus in this study area devoid of estuaries suggests that estuarine dependency may be regionally specific for some taxa. It appears that the warm, sheltered, nutrient rich waters of Tombua Bay provide typically estuarine associated taxa with a suitable alternative, non-estuarine nursery habitat. This study provides evidence that the importance of estuaries as critical nursery habitats has been overemphasized for some warm-temperate coastal fishes. However, the absence of other marine estuarine dependent species from the study area suggests that some warm-temperate taxa do intrinsically rely on estuarine function for survival.
- Full Text:
- Date Issued: 2017
- Authors: Farthing, Matthew William
- Date: 2017
- Subjects: Fishes -- Larvae -- South Africa -- Atlantic coast , Fishes -- Larvae -- Angola -- Atlantic coast , Striped mullet -- Angola -- Atlantic coast
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/50442 , vital:25988
- Description: Early stage fishes (larvae and early juveniles) were collected from an array of shallow water (±1.5m) habitats on the warm-temperate southern Angolan coastline between June 2014 and June 2015. This study, the first assessment of the early stages of coastal fishes in Angola, provides important new understanding of non-estuarine shallow water nursery habitat use by coastal fishes from the region. In total, 51 species from 18 teleost families were observed. The exposed surf zone was dominated by postflexion larvae, while the moderately exposed beach and sheltered bay were dominated by early juveniles. Both fish density and diversity peaked in the wet season (Feb – Apr 2015) for all habitats, attributed to the influx of summer spawning species. Diplodus sargus dominated catches from the exposed surf zone, and the timing of observations supports the growing consensus that sparid spawning is dictated by temperature, not season. The similitude of the observed species to those observed in warm temperate South Africa highlights the historical connection of the warm-temperate study area with warm-temperate South Africa, prior to the formation of the Benguela Current as a vicariant barrier. The classification of the study assemblage into established estuarine utilization categories showed that the surf zone hosted more exclusively marine species than comparable surf zones in South Africa, attributed to the absence of estuaries in southern Angola. However, the observation of the marine estuarine dependent Mugil cephalus in this study area devoid of estuaries suggests that estuarine dependency may be regionally specific for some taxa. It appears that the warm, sheltered, nutrient rich waters of Tombua Bay provide typically estuarine associated taxa with a suitable alternative, non-estuarine nursery habitat. This study provides evidence that the importance of estuaries as critical nursery habitats has been overemphasized for some warm-temperate coastal fishes. However, the absence of other marine estuarine dependent species from the study area suggests that some warm-temperate taxa do intrinsically rely on estuarine function for survival.
- Full Text:
- Date Issued: 2017
Experiences of pet loss in the South African context
- Authors: Lowen, Kathleen Louise
- Date: 2017
- Subjects: Pet loss -- Psychological aspects , Pet loss -- South Africa -- Case studies , Pets -- Death , Pet ownders -- Psychology , Human-animal relationships -- Psychological aspects , Grief
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/4326 , vital:20649
- Description: In this research the experience of pet loss in relation to the intensity of grief and the repression of that grief due to societal restrictions was studied in a South African sample of 12 pet owners who had experienced the loss of a pet within 24 months prior to the study. A pilot study was conducted in order to refine the semi-structured interview schedule. Participants were asked about their pets, their experience of pet loss in relation to their feelings before and after the loss and whether they felt they could openly grieve around friends and family. The findings indicated that the intensity of grief experienced by the participants was influenced both by the intensity of their Bond with the pet and the repression of their grief due to assumed social sanctions surrounding mourning the loss of a pet. The findings from the study clearly indicate the necessity for pet loss counselling, however it was clear that societal views surrounding pet loss are shifting, thus allowing pet owners to mourn their loss more openly with family and friends. This indicates a decrease in cases of disenfranchised and complicated grief. Furthermore the impact of pet loss necessitates the social legitimation and acknowledgment of the significance of pet loss in contemporary society as these relationships with pets are an increasingly prominent feature both within and as an alternative to familial systems.
- Full Text:
- Date Issued: 2017
- Authors: Lowen, Kathleen Louise
- Date: 2017
- Subjects: Pet loss -- Psychological aspects , Pet loss -- South Africa -- Case studies , Pets -- Death , Pet ownders -- Psychology , Human-animal relationships -- Psychological aspects , Grief
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/4326 , vital:20649
- Description: In this research the experience of pet loss in relation to the intensity of grief and the repression of that grief due to societal restrictions was studied in a South African sample of 12 pet owners who had experienced the loss of a pet within 24 months prior to the study. A pilot study was conducted in order to refine the semi-structured interview schedule. Participants were asked about their pets, their experience of pet loss in relation to their feelings before and after the loss and whether they felt they could openly grieve around friends and family. The findings indicated that the intensity of grief experienced by the participants was influenced both by the intensity of their Bond with the pet and the repression of their grief due to assumed social sanctions surrounding mourning the loss of a pet. The findings from the study clearly indicate the necessity for pet loss counselling, however it was clear that societal views surrounding pet loss are shifting, thus allowing pet owners to mourn their loss more openly with family and friends. This indicates a decrease in cases of disenfranchised and complicated grief. Furthermore the impact of pet loss necessitates the social legitimation and acknowledgment of the significance of pet loss in contemporary society as these relationships with pets are an increasingly prominent feature both within and as an alternative to familial systems.
- Full Text:
- Date Issued: 2017
Synthesis and biological evaluation of anti-HIV-I integrase agents
- Jesumoroti, Omobolanle Janet
- Authors: Jesumoroti, Omobolanle Janet
- Date: 2017
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/59215 , vital:27479
- Description: Expected release date-April 2019
- Full Text:
- Date Issued: 2017
- Authors: Jesumoroti, Omobolanle Janet
- Date: 2017
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/59215 , vital:27479
- Description: Expected release date-April 2019
- Full Text:
- Date Issued: 2017
The impact of good news and bad news on South Africa’s sectoral stock return volatility: an asymmetric GARCH analysis
- Authors: Muzinda, Edmond Toreva
- Date: 2017
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: http://hdl.handle.net/10962/6425 , vital:21108
- Description: This study explores the impact of good news and bad news on South Africa’s sectoral stock return volatility using an asymmetric GARCH analysis. Understanding the different impact of news on stock return volatility in different economic sectors has important implications for investors’ risk management practices, portfolio allocation strategies and asset pricing. The study employs data of daily closing prices for nine sectors and three benchmark indices for the period 2nd January 1997 - 17th August 2016. The data was split into sub-samples of pre-, during and post-global financial crisis, as well as the overall sample period. The incorporation of sub-samples was to help explain the outcomes of the overall sample period. To capture the different impact of good news and bad news on stock return volatility for each sector, asymmetric GARCH models namely, TGARCH and EGARCH were employed. The findings from this study revealed that volatility asymmetry was present in all sectors and benchmark indices of South African equity market. Bad news had more impact on stock return volatility for all sectors except the Oil and Gas sector, than good news of the same magnitude. In the Oil and Gas sector, good news was found to have an amplified effect on return volatility compared with bad news of the same magnitude. High volatility persistence was also found to be present in the Consumer goods, Financials, Industrials, All-share index and Mid-cap index. High differential impact of good and bad news were found in the Industrials, Financials, Basic materials, Consumer goods and the All-share index. Since the main objective of this study was to provide explanations of volatility asymmetry found in the South African sectors, the following were proposed as possible explanations of the findings. Within sectors, volatility asymmetry was explained by financial leverage, the role of the media, loss-averse investors and the behaviour of traders (overconfidence and extrapolation bias). Volatility asymmetry across sectors was explained by information flow, the uneven distribution of information by the media, investor sentiments, investor expectations and trading volumes. Overall, the results indicate that the stock return volatility of individual sectors of the South African equity market is driven mainly by bad news (except for Oil and Gas) and that leverage effects exist in all the sectors and in the benchmark indices.
- Full Text:
- Date Issued: 2017
- Authors: Muzinda, Edmond Toreva
- Date: 2017
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: http://hdl.handle.net/10962/6425 , vital:21108
- Description: This study explores the impact of good news and bad news on South Africa’s sectoral stock return volatility using an asymmetric GARCH analysis. Understanding the different impact of news on stock return volatility in different economic sectors has important implications for investors’ risk management practices, portfolio allocation strategies and asset pricing. The study employs data of daily closing prices for nine sectors and three benchmark indices for the period 2nd January 1997 - 17th August 2016. The data was split into sub-samples of pre-, during and post-global financial crisis, as well as the overall sample period. The incorporation of sub-samples was to help explain the outcomes of the overall sample period. To capture the different impact of good news and bad news on stock return volatility for each sector, asymmetric GARCH models namely, TGARCH and EGARCH were employed. The findings from this study revealed that volatility asymmetry was present in all sectors and benchmark indices of South African equity market. Bad news had more impact on stock return volatility for all sectors except the Oil and Gas sector, than good news of the same magnitude. In the Oil and Gas sector, good news was found to have an amplified effect on return volatility compared with bad news of the same magnitude. High volatility persistence was also found to be present in the Consumer goods, Financials, Industrials, All-share index and Mid-cap index. High differential impact of good and bad news were found in the Industrials, Financials, Basic materials, Consumer goods and the All-share index. Since the main objective of this study was to provide explanations of volatility asymmetry found in the South African sectors, the following were proposed as possible explanations of the findings. Within sectors, volatility asymmetry was explained by financial leverage, the role of the media, loss-averse investors and the behaviour of traders (overconfidence and extrapolation bias). Volatility asymmetry across sectors was explained by information flow, the uneven distribution of information by the media, investor sentiments, investor expectations and trading volumes. Overall, the results indicate that the stock return volatility of individual sectors of the South African equity market is driven mainly by bad news (except for Oil and Gas) and that leverage effects exist in all the sectors and in the benchmark indices.
- Full Text:
- Date Issued: 2017
“The Hellenistic ruler cult and Ptolemy I’s quest for legitimacy”
- Authors: Ntuli, Sihle
- Date: 2017
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/6097 , vital:21031
- Description: Alexander III died suddenly in Babylon in 323 BC. With Philip III Arrhidaeus in a mentally deficient state and Alexander IV not being of age, Alexander died without a suitable heir. The task of succeeding one of the most storied legacies in the ancient world was left to the generals of Alexander III. On his deathbed, Alexander was asked who should lead the Macedonians, of which he allegedly replied “the strongest”. Thus began the process of selecting the individual who would succeed Alexander the Great, which ended up becoming a contentious task due to Macedonian succession customs. Subsequently the ‘Successors’ quarrelled over who should succeed Alexander as the true successor. The wars of the Successors are founded on an issue of legitimacy that qualifies the notion of the strongest. Being deemed the true successor of Alexander the Great meant the opportunity to continue a period of Macedonian dominance following the reigns of Philip II and Alexander III. Alexander III is hailed as one of the most extraordinary individuals of the ancient world with his imperial campaigns being widely documented, political stability being pinpointed as one of the Macedonian strong points during the period of their dominance. The ruler cult is a point of reference for the explaining the relative political stability throughout the reign of Alexander the Great. The ruler cult can be understood as a sociopolitical construct that hybridized the notion of the ruler with that of a religious leader. The oriental influence of Alexander’s campaigns in Asia would inform the customs and practices of the divine ruler. The Macedonians’ ability to establish a presence in foreign territories made such a social construct a necessity in the task of centralizing of minds for political stability. Alexander’s rendition of the cult informed the formalized Ptolemaic ruler cult. The similarities and differences of the renditions help us to understand this political tool that Ptolemy I required in order to be deemed the true successor of Alexander the Great. The following will be an investigation into whether Ptolemy I is able to attain legitimacy, firstly as a successor to Alexander the Great, secondly as Pharaoh of Egypt.
- Full Text:
- Date Issued: 2017
- Authors: Ntuli, Sihle
- Date: 2017
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/6097 , vital:21031
- Description: Alexander III died suddenly in Babylon in 323 BC. With Philip III Arrhidaeus in a mentally deficient state and Alexander IV not being of age, Alexander died without a suitable heir. The task of succeeding one of the most storied legacies in the ancient world was left to the generals of Alexander III. On his deathbed, Alexander was asked who should lead the Macedonians, of which he allegedly replied “the strongest”. Thus began the process of selecting the individual who would succeed Alexander the Great, which ended up becoming a contentious task due to Macedonian succession customs. Subsequently the ‘Successors’ quarrelled over who should succeed Alexander as the true successor. The wars of the Successors are founded on an issue of legitimacy that qualifies the notion of the strongest. Being deemed the true successor of Alexander the Great meant the opportunity to continue a period of Macedonian dominance following the reigns of Philip II and Alexander III. Alexander III is hailed as one of the most extraordinary individuals of the ancient world with his imperial campaigns being widely documented, political stability being pinpointed as one of the Macedonian strong points during the period of their dominance. The ruler cult is a point of reference for the explaining the relative political stability throughout the reign of Alexander the Great. The ruler cult can be understood as a sociopolitical construct that hybridized the notion of the ruler with that of a religious leader. The oriental influence of Alexander’s campaigns in Asia would inform the customs and practices of the divine ruler. The Macedonians’ ability to establish a presence in foreign territories made such a social construct a necessity in the task of centralizing of minds for political stability. Alexander’s rendition of the cult informed the formalized Ptolemaic ruler cult. The similarities and differences of the renditions help us to understand this political tool that Ptolemy I required in order to be deemed the true successor of Alexander the Great. The following will be an investigation into whether Ptolemy I is able to attain legitimacy, firstly as a successor to Alexander the Great, secondly as Pharaoh of Egypt.
- Full Text:
- Date Issued: 2017
Ngomso 'special school': contestations of morality and education in the Eastern Cape
- Authors: Pattenden, Oliver
- Date: 2017
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/65200 , vital:28704
- Description: Expected release date-May 2019
- Full Text:
- Date Issued: 2017
- Authors: Pattenden, Oliver
- Date: 2017
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/65200 , vital:28704
- Description: Expected release date-May 2019
- Full Text:
- Date Issued: 2017
A critical evaluation of inter-jurisdictional rules in the South African value-added tax system
- Authors: Schneider, Ferdinand Dirk
- Date: 2017
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/7971 , vital:21329
- Description: This study analysed the current inter-jurisdictional rules in the South African Value-Added Tax (VAT) system, identified shortcomings, and proposed legislative amendments or additions to address these shortcomings. The research was conducted within an interpretative post positivism paradigm, applied a qualitative research methodology, and a doctrinal research method. A detailed review of the literature was conducted to establish the theoretical basis of a good tax system and the theory underpinning indirect and consumption taxation. The literature review also included an in-depth analysis of the South African VAT system and its treatment of resident and non-resident businesses with a South African physical or economic reach, and its treatment of local and cross-border transactions, including imported services. The literature review also considered the international VAT treatment of these transactions. To obtain a wider range of expert opinions regarding shortcomings in inter-jurisdictional rules in the South African VAT system, data was collected through structured interviews with South African and global VAT and indirect tax experts, using a questionnaire that was specifically designed for this purpose. This study proposed amendments and additions to the VAT Act, dealing with the VAT registration of non-resident suppliers; addressing various issues relating to the interjurisdictional VAT rate; proposing measures in connection with imported services; and legislating the intention of the legislator to tax final utilisation or consumption. The study finally recommended the introduction of a general place of supply rule linked to residency; specific place of supply rules for electronic, broadcasting, and telecommunication services; and zero rating provisions for electronic, broadcasting, and telecommunication services provided to non-resident suppliers by resident suppliers for services initiated outside South Africa.
- Full Text:
- Date Issued: 2017
- Authors: Schneider, Ferdinand Dirk
- Date: 2017
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/7971 , vital:21329
- Description: This study analysed the current inter-jurisdictional rules in the South African Value-Added Tax (VAT) system, identified shortcomings, and proposed legislative amendments or additions to address these shortcomings. The research was conducted within an interpretative post positivism paradigm, applied a qualitative research methodology, and a doctrinal research method. A detailed review of the literature was conducted to establish the theoretical basis of a good tax system and the theory underpinning indirect and consumption taxation. The literature review also included an in-depth analysis of the South African VAT system and its treatment of resident and non-resident businesses with a South African physical or economic reach, and its treatment of local and cross-border transactions, including imported services. The literature review also considered the international VAT treatment of these transactions. To obtain a wider range of expert opinions regarding shortcomings in inter-jurisdictional rules in the South African VAT system, data was collected through structured interviews with South African and global VAT and indirect tax experts, using a questionnaire that was specifically designed for this purpose. This study proposed amendments and additions to the VAT Act, dealing with the VAT registration of non-resident suppliers; addressing various issues relating to the interjurisdictional VAT rate; proposing measures in connection with imported services; and legislating the intention of the legislator to tax final utilisation or consumption. The study finally recommended the introduction of a general place of supply rule linked to residency; specific place of supply rules for electronic, broadcasting, and telecommunication services; and zero rating provisions for electronic, broadcasting, and telecommunication services provided to non-resident suppliers by resident suppliers for services initiated outside South Africa.
- Full Text:
- Date Issued: 2017
A critical analysis of housing provision, livelihood activities and social reproduction in urban communities in South Africa: the case of Ezamokuhle, Mpumalanga
- Authors: Nkambule, Sipho Jonathan
- Date: 2017
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/7788 , vital:21298
- Description: The post-apartheid South African state has formulated, introduced and implemented nationwide policies and programmes pertaining to urban housing in order to address and tackle the challenges of social reproduction in and for poor urban black communities. This however has been undermined for a number of reasons, such as state incapacities and the state’s neo-liberal overreliance on the market to remedy past injustices. At the same time households, as critical sites of social reproduction in poor urban black communities and under conditions of extreme vulnerability, engage in a range of productive and non-productive activities often in a desperate bid to construct and maintain a semblance of livelihood sustainability. The thesis seeks to critically understand the relationship between state housing programmes and the diverse livelihood activities of poor urban black households in South Africa in the context of an ongoing systemic crisis of social reproduction which exists in these urban communities. This is pursued with specific reference to eZamokuhle Township in Amersfoort, Mpumalanga Province. The thesis is framed conceptually in terms of the notion of social reproduction. In doing so, it brings together two sets of literature which are often disconnected. On the one hand, there is South African literature which critically analyses the post-apartheid state’s housing programmes including the many challenges which exist in this regard. On the other hand, there is literature which considers the urban livelihoods of poor black communities in contemporary South Africa and often from within some kind of livelihoods perspective. The thesis is innovative in bringing these two sets of literature together in terms of the overarching notion of social reproduction and providing, therefore, a more holistic and integrated understanding of the multi-dimensional character of social reproduction. The depth of the crisis of social reproduction in eZamokuhle is explicated and examined in this way but in a manner which articulates the lived experiences and agency of eZamokhule households despite vulnerability constraints and challenges.
- Full Text:
- Date Issued: 2017
- Authors: Nkambule, Sipho Jonathan
- Date: 2017
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/7788 , vital:21298
- Description: The post-apartheid South African state has formulated, introduced and implemented nationwide policies and programmes pertaining to urban housing in order to address and tackle the challenges of social reproduction in and for poor urban black communities. This however has been undermined for a number of reasons, such as state incapacities and the state’s neo-liberal overreliance on the market to remedy past injustices. At the same time households, as critical sites of social reproduction in poor urban black communities and under conditions of extreme vulnerability, engage in a range of productive and non-productive activities often in a desperate bid to construct and maintain a semblance of livelihood sustainability. The thesis seeks to critically understand the relationship between state housing programmes and the diverse livelihood activities of poor urban black households in South Africa in the context of an ongoing systemic crisis of social reproduction which exists in these urban communities. This is pursued with specific reference to eZamokuhle Township in Amersfoort, Mpumalanga Province. The thesis is framed conceptually in terms of the notion of social reproduction. In doing so, it brings together two sets of literature which are often disconnected. On the one hand, there is South African literature which critically analyses the post-apartheid state’s housing programmes including the many challenges which exist in this regard. On the other hand, there is literature which considers the urban livelihoods of poor black communities in contemporary South Africa and often from within some kind of livelihoods perspective. The thesis is innovative in bringing these two sets of literature together in terms of the overarching notion of social reproduction and providing, therefore, a more holistic and integrated understanding of the multi-dimensional character of social reproduction. The depth of the crisis of social reproduction in eZamokuhle is explicated and examined in this way but in a manner which articulates the lived experiences and agency of eZamokhule households despite vulnerability constraints and challenges.
- Full Text:
- Date Issued: 2017
Exploring the relationship between course pedagogy and learning in workplaces: the case of the National Diploma in Environmental Education Training and Development Practice
- Authors: Misser, Shanu
- Date: 2017
- Subjects: National Diploma in Environmental Education Training and Development Practice , Environmental education -- South Africa , Occupational training -- South Africa
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: http://hdl.handle.net/10962/8104 , vital:21354
- Description: This case study research provides insights on course pedagogy in the National Diploma in Environmental Education Training and Development Practice as registered with the South African Qualifications Authority. The study draws its findings from interviews, observations, and document analysis of course materials and workshop processes. The two case studies of employees working in a municipal and a provincial context in South Africa provide rich insights into workplace practices and its implications for pedagogical approaches in work-integrated courses. The role of scaffolding, reflexivity and situated learning in creating learning experiences that learners have a reason to value emerge as significant approaches to be considered in pedagogy for work-integrated courses. Critical open-ended questions supported by course material design, dialogue, participation in cooperative learning situation underpinned by reading and the use of case studies and real situated experiences emerge as important pedagogical approaches enabling scaffolding and reflexivity to support a “critical mode of being”. The significant role of pedagogical approaches in maintaining relevance to workplace practices are seen as important in developing capabilities of participants to value what they do on courses. Linked to the insights gained from this study three important recommendations are made. The first recommendation suggests that a pedagogical approach, which involves learner-practitioners and workplace representatives in the curriculum design, would help to maintain relevance of the assignments to the workplace. The second recommendation suggests creative and innovative pedagogical approaches to capture workplace practices in real authentic and meaningful situations for assessment. The third recommendation suggests that pedagogies used in workplace courses need to consider social-ecological sustainability competencies that transgress job tasks across occupations which foster appreciation and imagination of new possibilities in the work learner-practitioners engage in.
- Full Text:
- Date Issued: 2017
- Authors: Misser, Shanu
- Date: 2017
- Subjects: National Diploma in Environmental Education Training and Development Practice , Environmental education -- South Africa , Occupational training -- South Africa
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: http://hdl.handle.net/10962/8104 , vital:21354
- Description: This case study research provides insights on course pedagogy in the National Diploma in Environmental Education Training and Development Practice as registered with the South African Qualifications Authority. The study draws its findings from interviews, observations, and document analysis of course materials and workshop processes. The two case studies of employees working in a municipal and a provincial context in South Africa provide rich insights into workplace practices and its implications for pedagogical approaches in work-integrated courses. The role of scaffolding, reflexivity and situated learning in creating learning experiences that learners have a reason to value emerge as significant approaches to be considered in pedagogy for work-integrated courses. Critical open-ended questions supported by course material design, dialogue, participation in cooperative learning situation underpinned by reading and the use of case studies and real situated experiences emerge as important pedagogical approaches enabling scaffolding and reflexivity to support a “critical mode of being”. The significant role of pedagogical approaches in maintaining relevance to workplace practices are seen as important in developing capabilities of participants to value what they do on courses. Linked to the insights gained from this study three important recommendations are made. The first recommendation suggests that a pedagogical approach, which involves learner-practitioners and workplace representatives in the curriculum design, would help to maintain relevance of the assignments to the workplace. The second recommendation suggests creative and innovative pedagogical approaches to capture workplace practices in real authentic and meaningful situations for assessment. The third recommendation suggests that pedagogies used in workplace courses need to consider social-ecological sustainability competencies that transgress job tasks across occupations which foster appreciation and imagination of new possibilities in the work learner-practitioners engage in.
- Full Text:
- Date Issued: 2017
Language and literacy development for a Grade 10 English first additional language classroom: a reading to learn case study
- Authors: Mataka, Tawanda Wallace
- Date: 2017
- Subjects: English language -- Study and teching (Secondary) -- South Africa Reading -- Study and teching (Secondary) -- South Africa Literacy -- Study and teching (Secondary) -- South Africa
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: http://hdl.handle.net/10962/249 , vital:19941
- Description: The problem of poor reading skills is a serious one in South Africa, with negative implications for learners’ educational achievement. The failure of learners to read at age- and grade-appropriate levels presents a major challenge to the teaching of reading in South African schools. It is against this background that this study aimed at ascertaining the positive impact of the Reading to Learn methodology in improving the literacy levels of learners in a Grade 10 English First Additional Language classroom in a township school. Reading ability levels were established via a passage extracted from a Grade Platinum English First Additional Learner’s book. Pronunciation and word recognition formed the basis of the reading assessment. Reading translates into writing, so the learners were also assessed in comprehension and creative writing. The results indicated that the learners’ reading abilities were weak, the methodology used to teach reading led to research findings that caused the study to yield findings that suggest that RtL may be the solution to reading problems in the classroom. In addition the study revealed that the ability to read corresponds with cognitive development. The study therefore calls for the adoption of RtL to assist in alleviating reading problems in the classroom.
- Full Text:
- Date Issued: 2017
- Authors: Mataka, Tawanda Wallace
- Date: 2017
- Subjects: English language -- Study and teching (Secondary) -- South Africa Reading -- Study and teching (Secondary) -- South Africa Literacy -- Study and teching (Secondary) -- South Africa
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: http://hdl.handle.net/10962/249 , vital:19941
- Description: The problem of poor reading skills is a serious one in South Africa, with negative implications for learners’ educational achievement. The failure of learners to read at age- and grade-appropriate levels presents a major challenge to the teaching of reading in South African schools. It is against this background that this study aimed at ascertaining the positive impact of the Reading to Learn methodology in improving the literacy levels of learners in a Grade 10 English First Additional Language classroom in a township school. Reading ability levels were established via a passage extracted from a Grade Platinum English First Additional Learner’s book. Pronunciation and word recognition formed the basis of the reading assessment. Reading translates into writing, so the learners were also assessed in comprehension and creative writing. The results indicated that the learners’ reading abilities were weak, the methodology used to teach reading led to research findings that caused the study to yield findings that suggest that RtL may be the solution to reading problems in the classroom. In addition the study revealed that the ability to read corresponds with cognitive development. The study therefore calls for the adoption of RtL to assist in alleviating reading problems in the classroom.
- Full Text:
- Date Issued: 2017
Understanding the policy-planning-implementation disjuncture: a case study of the Amathole District Municipality, Eastern Cape Province
- Authors: Mhlahlo, Andile
- Date: 2017
- Subjects: Municipal services -- South Africa -- Eastern Cape , Political planning -- South Africa -- Eastern Cape , Local government -- South Africa -- Eastern Cape , Amathole District Municipality (South Africa) -- Planning
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/168521 , vital:41591
- Description: The aim of this study is to investigate why well planned policies are not getting implemented as intended. The study was conducted in the offices of Amathole District Municipality (ADM) in the Eastern Cape Province, including the cooperative project in Alice as one of the projects that was coordinated by the ADM. Concerning the research design and methodology, a qualitative research design was used. The data collection process involved conducting unstructured interviews with the officers from the Amathole District Municipality office (the ADM officers / the municipality officers) and the members of cooperative projects (cooperatives/projects). Mainly, an ethnographic approach was used; it involved embracing participant observation in the ADM offices for approximately 6 months. As the researcher, I participated as one of the ADM’s officers in different activities, namely: attending meetings and one workshop, and accompanying the development officer while conducting an observation of various projects in Butterworth. The findings in the study disclose that the disjuncture between policy planning and implementation may be attributed to 4 factors, which are associated with the ADM office as the development agency for the Amathole region. These are: the incapability to respond to policy implementation complexities, failure to exploit policy implementation complexities as learning opportunities, the insufficient understanding of ‘process monitoring’ as a tool that could be integrated in projects management, as well as the execution of policy implementation in the absence of policy documents as a guide in implementation processes. Moreover, these factors are examined as being related to each other, and they will be discussed in detail in the course of the thesis.
- Full Text:
- Date Issued: 2017
- Authors: Mhlahlo, Andile
- Date: 2017
- Subjects: Municipal services -- South Africa -- Eastern Cape , Political planning -- South Africa -- Eastern Cape , Local government -- South Africa -- Eastern Cape , Amathole District Municipality (South Africa) -- Planning
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/168521 , vital:41591
- Description: The aim of this study is to investigate why well planned policies are not getting implemented as intended. The study was conducted in the offices of Amathole District Municipality (ADM) in the Eastern Cape Province, including the cooperative project in Alice as one of the projects that was coordinated by the ADM. Concerning the research design and methodology, a qualitative research design was used. The data collection process involved conducting unstructured interviews with the officers from the Amathole District Municipality office (the ADM officers / the municipality officers) and the members of cooperative projects (cooperatives/projects). Mainly, an ethnographic approach was used; it involved embracing participant observation in the ADM offices for approximately 6 months. As the researcher, I participated as one of the ADM’s officers in different activities, namely: attending meetings and one workshop, and accompanying the development officer while conducting an observation of various projects in Butterworth. The findings in the study disclose that the disjuncture between policy planning and implementation may be attributed to 4 factors, which are associated with the ADM office as the development agency for the Amathole region. These are: the incapability to respond to policy implementation complexities, failure to exploit policy implementation complexities as learning opportunities, the insufficient understanding of ‘process monitoring’ as a tool that could be integrated in projects management, as well as the execution of policy implementation in the absence of policy documents as a guide in implementation processes. Moreover, these factors are examined as being related to each other, and they will be discussed in detail in the course of the thesis.
- Full Text:
- Date Issued: 2017
Understanding the policy-planning-implementation disjuncture: a case study of the Amathole District Municipality, Eastern Cape Province
- Authors: Mhlahlo, Andile
- Date: 2017
- Subjects: Municipal services -- South Africa -- Eastern Cape , Political planning -- South Africa -- Eastern Cape , Local government -- South Africa -- Eastern Cape , Amathole District Municipality (South Africa) -- Planning
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/4422 , vital:20668
- Description: The aim of this study is to investigate why well planned policies are not getting implemented as intended. The study was conducted in the offices of Amathole District Municipality (ADM) in the Eastern Cape Province, including the cooperative project in Alice as one of the projects that was coordinated by the ADM. Concerning the research design and methodology, a qualitative research design was used. The data collection process involved conducting unstructured interviews with the officers from the Amathole District Municipality office (the ADM officers / the municipality officers) and the members of cooperative projects (cooperatives/projects). Mainly, an ethnographic approach was used; it involved embracing participant observation in the ADM offices for approximately 6 months. As the researcher, I participated as one of the ADM’s officers in different activities, namely: attending meetings and one workshop, and accompanying the development officer while conducting an observation of various projects in Butterworth. The findings in the study disclose that the disjuncture between policy planning and implementation may be attributed to 4 factors, which are associated with the ADM office as the development agency for the Amathole region. These are: the incapability to respond to policy implementation complexities, failure to exploit policy implementation complexities as learning opportunities, the insufficient understanding of ‘process monitoring’ as a tool that could be integrated in projects management, as well as the execution of policy implementation in the absence of policy documents as a guide in implementation processes. Moreover, these factors are examined as being related to each other, and they will be discussed in detail in the course of the thesis.
- Full Text:
- Date Issued: 2017
- Authors: Mhlahlo, Andile
- Date: 2017
- Subjects: Municipal services -- South Africa -- Eastern Cape , Political planning -- South Africa -- Eastern Cape , Local government -- South Africa -- Eastern Cape , Amathole District Municipality (South Africa) -- Planning
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/4422 , vital:20668
- Description: The aim of this study is to investigate why well planned policies are not getting implemented as intended. The study was conducted in the offices of Amathole District Municipality (ADM) in the Eastern Cape Province, including the cooperative project in Alice as one of the projects that was coordinated by the ADM. Concerning the research design and methodology, a qualitative research design was used. The data collection process involved conducting unstructured interviews with the officers from the Amathole District Municipality office (the ADM officers / the municipality officers) and the members of cooperative projects (cooperatives/projects). Mainly, an ethnographic approach was used; it involved embracing participant observation in the ADM offices for approximately 6 months. As the researcher, I participated as one of the ADM’s officers in different activities, namely: attending meetings and one workshop, and accompanying the development officer while conducting an observation of various projects in Butterworth. The findings in the study disclose that the disjuncture between policy planning and implementation may be attributed to 4 factors, which are associated with the ADM office as the development agency for the Amathole region. These are: the incapability to respond to policy implementation complexities, failure to exploit policy implementation complexities as learning opportunities, the insufficient understanding of ‘process monitoring’ as a tool that could be integrated in projects management, as well as the execution of policy implementation in the absence of policy documents as a guide in implementation processes. Moreover, these factors are examined as being related to each other, and they will be discussed in detail in the course of the thesis.
- Full Text:
- Date Issued: 2017
Stochastic models in finance
- Authors: Mazengera, Hassan
- Date: 2017
- Subjects: Finance -- Mathematical models , C++ (Computer program language) , GARCH model , Lebesgue-Radon-Nikodym theorems , Radon measures , Stochastic models , Stochastic processes , Stochastic processes -- Computer programs , Martingales (Mathematics) , Pricing -- Mathematical models
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/162724 , vital:40976
- Description: Stochastic models for pricing financial securities are developed. First, we consider the Black Scholes model, which is a classic example of a complete market model and finally focus on Lévy driven models. Jumps may render the market incomplete and are induced in a model by inclusion of a Poisson process. Lévy driven models are more realistic in modelling of asset price dynamics than the Black Scholes model. Martingales are central in pricing, especially of derivatives and we give them the desired attention in the context of pricing. There are an increasing number of important pricing models where analytical solutions are not available hence computational methods come in handy, see Broadie and Glasserman (1997). It is also important to note that computational methods are also applicable to models with analytical solutions. We computationally value selected stochastic financial models using C++. Computational methods are also used to value or price complex financial instruments such as path dependent derivatives. This pricing procedure is applied in the computational valuation of a stochastic (revenue based) loan contract. Derivatives with simple pay of functions and models with analytical solutions are considered for illustrative purposes. The Black-Scholes P.D.E is complex to solve analytically and finite difference methods are widely used. Explicit finite difference scheme is considered in this thesis for computational valuation of derivatives that are modelled by the Black-Scholes P.D.E. Stochastic modelling of asset prices is important for the valuation of derivatives: Gaussian, exponential and gamma variates are simulated for the valuation purposes.
- Full Text:
- Date Issued: 2017
- Authors: Mazengera, Hassan
- Date: 2017
- Subjects: Finance -- Mathematical models , C++ (Computer program language) , GARCH model , Lebesgue-Radon-Nikodym theorems , Radon measures , Stochastic models , Stochastic processes , Stochastic processes -- Computer programs , Martingales (Mathematics) , Pricing -- Mathematical models
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/162724 , vital:40976
- Description: Stochastic models for pricing financial securities are developed. First, we consider the Black Scholes model, which is a classic example of a complete market model and finally focus on Lévy driven models. Jumps may render the market incomplete and are induced in a model by inclusion of a Poisson process. Lévy driven models are more realistic in modelling of asset price dynamics than the Black Scholes model. Martingales are central in pricing, especially of derivatives and we give them the desired attention in the context of pricing. There are an increasing number of important pricing models where analytical solutions are not available hence computational methods come in handy, see Broadie and Glasserman (1997). It is also important to note that computational methods are also applicable to models with analytical solutions. We computationally value selected stochastic financial models using C++. Computational methods are also used to value or price complex financial instruments such as path dependent derivatives. This pricing procedure is applied in the computational valuation of a stochastic (revenue based) loan contract. Derivatives with simple pay of functions and models with analytical solutions are considered for illustrative purposes. The Black-Scholes P.D.E is complex to solve analytically and finite difference methods are widely used. Explicit finite difference scheme is considered in this thesis for computational valuation of derivatives that are modelled by the Black-Scholes P.D.E. Stochastic modelling of asset prices is important for the valuation of derivatives: Gaussian, exponential and gamma variates are simulated for the valuation purposes.
- Full Text:
- Date Issued: 2017
An investigation of how Visual Technology for the Autonomous Learning of Mathematics (VITALmaths) video clips on mobile phones can be used by student teachers as a visualisation tool in the teaching of Number Sense: a case study
- Authors: Kangwa, Lemmy
- Date: 2017
- Subjects: Mathematics -- Study and teaching -- Zambia -- Case studies , Visualization , Number concept , Mobile communication systems in education , Mathematics -- Study and teaching -- Software , Telecommunications in education , Educational innovations , VITALmaths
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: http://hdl.handle.net/10962/6930 , vital:21201
- Description: Visualisation is increasingly being recognised as having a significant role in the learning of mathematics especially when students are solving mathematical problems (Thornton, 2001). It is argued that visualisation is a powerful tool for learners to construct mental and physical representations that correctly mirror mathematical relationships and concepts. To gain a thorough understanding of the scope of visualisation, three Visual Technology for Autonomous Learning of Mathematics (VITALmaths) (www.vitalmaths.com) video clips were uploaded on mobile phones of each of the eleven participating student teachers who used them in their teaching practice. This is in cognisance of the educational potential offered by mobile phones and their current pervasiveness in the daily lives of both teachers and learners in Zambia (Zambia. Ministry of Education [M.O.E], 2013]). This study sought to investigate how VITALmaths video clips on mobile phones could be used by student teachers as a visualisation tool in the teaching of Number Sense. The videos of the lessons formed the core of my analysis. The study was conducted at four primary schools by eleven student teachers of a public university in Zambia. The study is framed as a case study and is grounded within the interpretive paradigm. The findings revealed that the student teachers’ use of the video clips in the classrooms for teaching was generally approached from two perspectives: at the beginning of the lesson or at the end. The videos were used at the beginning of the lesson as a means to introduce a topic or an idea, and at the end of the lesson to consolidate what was taught. The videos were also used to enhance the conceptual understanding of Number Sense. The findings also revealed that students encountered both enabling and constraining factors in their use of mobile phones to teach number sense. The overall findings revealed that, if well utilised, mobile phones as visualisation tools had the potential to enhance the teaching of Mathematics in general and Number Sense in particular, and therefore teachers should be encouraged to use them in their teaching.
- Full Text:
- Date Issued: 2017
- Authors: Kangwa, Lemmy
- Date: 2017
- Subjects: Mathematics -- Study and teaching -- Zambia -- Case studies , Visualization , Number concept , Mobile communication systems in education , Mathematics -- Study and teaching -- Software , Telecommunications in education , Educational innovations , VITALmaths
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: http://hdl.handle.net/10962/6930 , vital:21201
- Description: Visualisation is increasingly being recognised as having a significant role in the learning of mathematics especially when students are solving mathematical problems (Thornton, 2001). It is argued that visualisation is a powerful tool for learners to construct mental and physical representations that correctly mirror mathematical relationships and concepts. To gain a thorough understanding of the scope of visualisation, three Visual Technology for Autonomous Learning of Mathematics (VITALmaths) (www.vitalmaths.com) video clips were uploaded on mobile phones of each of the eleven participating student teachers who used them in their teaching practice. This is in cognisance of the educational potential offered by mobile phones and their current pervasiveness in the daily lives of both teachers and learners in Zambia (Zambia. Ministry of Education [M.O.E], 2013]). This study sought to investigate how VITALmaths video clips on mobile phones could be used by student teachers as a visualisation tool in the teaching of Number Sense. The videos of the lessons formed the core of my analysis. The study was conducted at four primary schools by eleven student teachers of a public university in Zambia. The study is framed as a case study and is grounded within the interpretive paradigm. The findings revealed that the student teachers’ use of the video clips in the classrooms for teaching was generally approached from two perspectives: at the beginning of the lesson or at the end. The videos were used at the beginning of the lesson as a means to introduce a topic or an idea, and at the end of the lesson to consolidate what was taught. The videos were also used to enhance the conceptual understanding of Number Sense. The findings also revealed that students encountered both enabling and constraining factors in their use of mobile phones to teach number sense. The overall findings revealed that, if well utilised, mobile phones as visualisation tools had the potential to enhance the teaching of Mathematics in general and Number Sense in particular, and therefore teachers should be encouraged to use them in their teaching.
- Full Text:
- Date Issued: 2017
Exploring Grade 12 Biology teachers’ conceptions, dispositions and pedagogic strategies when mediating learning of evolution in Namibia
- Authors: Katuuo, Henry U
- Date: 2017
- Subjects: Biology teachers -- Attitudes -- Namibia , Biology teachers -- Training of -- Namibia , Evolution -- Study and teaching -- Namibia
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: http://hdl.handle.net/10962/13762 , vital:21856
- Description: The Namibian Senior Secondary Certificate Examiners’ Reports (2013) shed light on the topics in which learners often perform poorly and evolution is one of such problematic topics. Anecdotal reasons include religious views of teachers, opposition by learners to the topic, and inadequate understanding of the subject content knowledge. I have not come across any literature on evolution in Namibia that formally look closely at this problem. We do not have a clear idea of what is going on in Namibian science classrooms, when evolution is taught. We do not have a clear idea of the factors at play in the teaching of evolution in these classrooms, either when it is done well and completely or when it is not so. It is against this background that I was inspired to engage in this study which examined teachers’ conceptions, dispositions and pedagogical strategies that they use when teaching evolution. The study is underpinned by an interpretive paradigm, which afforded me an opportunity to understand the teachers’ worldviews in relation to evolution. It also allowed me to gain insight on the pedagogical strategies that teachers use when mediating learning of the topic of evolution and its related concepts. Within the interpretive paradigm, a case study approach was adopted, using a mixed-method design generating both quantitative and qualitative data. Teachers from two regions, namely, the Hardap region and Khomas region, participated in the study. Data were generated using questionnaires, semi-structured interviews and lesson observations. Fifteen questionnaires were completed and from those questionnaires, the sample included six teachers (40%) from the Hardap region while nine teachers (60%) were from the Khomas region. For the interview, the sample included two teachers - one from each region. For the observations, I observed five teachers teaching evolution. I presented quantitative data in tables and graphs, whereas the qualitative data was analysed inductively using Vygotsky’s (1978) socio-cultural theory as a theoretical framework. In addition, I used Ogunniyi’s (2006) Contiguity Argumentative Theory (CAT) as an analytical framework. These theories were used as lenses to interpret and make sense of the qualitative data, which I colour coded to form sub-themes. Thereafter, overlapping sub-themes were combined to form themes, which were linked to the research questions and in relation to literature/theory. Similarly, overlapping themes were combined to form analytical statements. It emerged from the study that religious views did not play a large role in most teachers’ views and attitudes towards the teaching of evolution. Instead, it emerged that lack of content knowledge on evolution is the main factor that influences teachers’ views and attitudes towards teaching evolution in schools. This is quite profound, as the assumption is that when teachers are religious, the likelihood is that they would object to the teaching of evolution. In light of this, the study recommends that there is a need for professional development and support of science teachers, so that they are able to properly mediate the learning of evolution.
- Full Text:
- Date Issued: 2017
- Authors: Katuuo, Henry U
- Date: 2017
- Subjects: Biology teachers -- Attitudes -- Namibia , Biology teachers -- Training of -- Namibia , Evolution -- Study and teaching -- Namibia
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: http://hdl.handle.net/10962/13762 , vital:21856
- Description: The Namibian Senior Secondary Certificate Examiners’ Reports (2013) shed light on the topics in which learners often perform poorly and evolution is one of such problematic topics. Anecdotal reasons include religious views of teachers, opposition by learners to the topic, and inadequate understanding of the subject content knowledge. I have not come across any literature on evolution in Namibia that formally look closely at this problem. We do not have a clear idea of what is going on in Namibian science classrooms, when evolution is taught. We do not have a clear idea of the factors at play in the teaching of evolution in these classrooms, either when it is done well and completely or when it is not so. It is against this background that I was inspired to engage in this study which examined teachers’ conceptions, dispositions and pedagogical strategies that they use when teaching evolution. The study is underpinned by an interpretive paradigm, which afforded me an opportunity to understand the teachers’ worldviews in relation to evolution. It also allowed me to gain insight on the pedagogical strategies that teachers use when mediating learning of the topic of evolution and its related concepts. Within the interpretive paradigm, a case study approach was adopted, using a mixed-method design generating both quantitative and qualitative data. Teachers from two regions, namely, the Hardap region and Khomas region, participated in the study. Data were generated using questionnaires, semi-structured interviews and lesson observations. Fifteen questionnaires were completed and from those questionnaires, the sample included six teachers (40%) from the Hardap region while nine teachers (60%) were from the Khomas region. For the interview, the sample included two teachers - one from each region. For the observations, I observed five teachers teaching evolution. I presented quantitative data in tables and graphs, whereas the qualitative data was analysed inductively using Vygotsky’s (1978) socio-cultural theory as a theoretical framework. In addition, I used Ogunniyi’s (2006) Contiguity Argumentative Theory (CAT) as an analytical framework. These theories were used as lenses to interpret and make sense of the qualitative data, which I colour coded to form sub-themes. Thereafter, overlapping sub-themes were combined to form themes, which were linked to the research questions and in relation to literature/theory. Similarly, overlapping themes were combined to form analytical statements. It emerged from the study that religious views did not play a large role in most teachers’ views and attitudes towards the teaching of evolution. Instead, it emerged that lack of content knowledge on evolution is the main factor that influences teachers’ views and attitudes towards teaching evolution in schools. This is quite profound, as the assumption is that when teachers are religious, the likelihood is that they would object to the teaching of evolution. In light of this, the study recommends that there is a need for professional development and support of science teachers, so that they are able to properly mediate the learning of evolution.
- Full Text:
- Date Issued: 2017
Assessing the potential role of microorganisms in the production of seedlings for the restoration of Albany Thicket
- Authors: Mpama, Nelisa
- Date: 2017
- Subjects: Vesicular-arbuscular mycorrhizas , Rhizobacteria , Restoration ecology South Africa Albany , Microorganisms
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/64555 , vital:28558
- Description: The role of microorganisms in restoration of the Albany Thicket has not been well documented, although the benefits to plants of these various interactions has been well documented. Microorganisms are chief ecological engineers and assist in resolving environmental problems and act to restore degraded ecosystem function by forming mutual relationships with the roots of the plants. The aim of this study was to assess the potential of microorganisms for the improved biomass production of selected woody and succulent seedlings used in mesic thicket restoration. Three tree species were selected for propagation in this study namely; Mystroxylon aethiopicum Scutia myrtina and Aloe ferox. Soil samples were collected from a degraded and intact thicket site from Bathurst, South Africa. Soils were evaluated for number of arbuscular mycorrhizal (AM) spores, mycorrhizal infectivity potential and nutrient availability both before and after seedling propagation. Pasteurized soil from the degraded site was used in a pot trial. Ten replicates seedling for plant species were planted and subjected to four treatments which included inoculation with AM fungi and the rhizobacterium, Enterobacter sp., alone and in combination; the fourth treatment was an un-inouclated control. Plant growth parameters were recorded at regular intervals where appropriate and seedlings were harvested after 24 weeks for biomass measurements and AM colonisation assessments. Although generally low (< 1 spore per gram) the density of AM fungal spores was significantly higher in soils from the intact site when compared with soils from the degraded site. The mycorrhizal potential of the soils was however not significantly different. Mystroxylon aethiopicum seedling shoot height, canopy diameter and shoot biomass showed a significant increase when inoculated with AM fungi while S. myrtina seedlings showed increased shoot height when inoculated with both AM fungi and Enterobacter sp. Aloe ferox seedlings did not respond to microbial inoculation. The concentration of soil P and Na increased in treatments with Enterobacter sp. alone and in combination with AM fungi. Mystroxylon aethiopicum and S. myrtina seedlings showed a dependency on microbial inoculants indicating the importance of inoculation in the nursery before planting out into the field. Overall AM fungal inoculants applied to seedlings can be used to compensate for nutrient deficiency in soils. Although the Enterobacter isolate used was known to have various plant growth promoting capabilities. It is recommended that other rhizobacterial isolates be investigated. , Thesis (MSc) -- Faculty of Science, Environmental Science, 2017
- Full Text:
- Date Issued: 2017
- Authors: Mpama, Nelisa
- Date: 2017
- Subjects: Vesicular-arbuscular mycorrhizas , Rhizobacteria , Restoration ecology South Africa Albany , Microorganisms
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/64555 , vital:28558
- Description: The role of microorganisms in restoration of the Albany Thicket has not been well documented, although the benefits to plants of these various interactions has been well documented. Microorganisms are chief ecological engineers and assist in resolving environmental problems and act to restore degraded ecosystem function by forming mutual relationships with the roots of the plants. The aim of this study was to assess the potential of microorganisms for the improved biomass production of selected woody and succulent seedlings used in mesic thicket restoration. Three tree species were selected for propagation in this study namely; Mystroxylon aethiopicum Scutia myrtina and Aloe ferox. Soil samples were collected from a degraded and intact thicket site from Bathurst, South Africa. Soils were evaluated for number of arbuscular mycorrhizal (AM) spores, mycorrhizal infectivity potential and nutrient availability both before and after seedling propagation. Pasteurized soil from the degraded site was used in a pot trial. Ten replicates seedling for plant species were planted and subjected to four treatments which included inoculation with AM fungi and the rhizobacterium, Enterobacter sp., alone and in combination; the fourth treatment was an un-inouclated control. Plant growth parameters were recorded at regular intervals where appropriate and seedlings were harvested after 24 weeks for biomass measurements and AM colonisation assessments. Although generally low (< 1 spore per gram) the density of AM fungal spores was significantly higher in soils from the intact site when compared with soils from the degraded site. The mycorrhizal potential of the soils was however not significantly different. Mystroxylon aethiopicum seedling shoot height, canopy diameter and shoot biomass showed a significant increase when inoculated with AM fungi while S. myrtina seedlings showed increased shoot height when inoculated with both AM fungi and Enterobacter sp. Aloe ferox seedlings did not respond to microbial inoculation. The concentration of soil P and Na increased in treatments with Enterobacter sp. alone and in combination with AM fungi. Mystroxylon aethiopicum and S. myrtina seedlings showed a dependency on microbial inoculants indicating the importance of inoculation in the nursery before planting out into the field. Overall AM fungal inoculants applied to seedlings can be used to compensate for nutrient deficiency in soils. Although the Enterobacter isolate used was known to have various plant growth promoting capabilities. It is recommended that other rhizobacterial isolates be investigated. , Thesis (MSc) -- Faculty of Science, Environmental Science, 2017
- Full Text:
- Date Issued: 2017
Nontsizi Mgqwetho’s the nation’s bounty: a prophetic voice towards an African literary theory
- Authors: Nxasana, Thulani
- Date: 2017
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/4547 , vital:20687
- Description: This thesis seeks to examine the ways in which Africans and African scholarship in particular have relied on the West to lead the way in scientific inquiry, theory and ways of approaching literary texts thus the stunting effects of this in the growth and development of uniquely African literary scholarship and theorising. In his seminal work, Decolonising the Mind, Wa Thiong’o (1987a) stresses that “...how we view ourselves, our environment even, is very much dependent on where we stand in relationship to imperialism in its colonial and neocolonial stages; that if we are to do anything about our individual and collective being today, then we have to coldly and consciously look at what imperialism has been doing to us and to our view of ourselves in the universe” (Wa Thiong’o, 1987a, p.88). Although most African countries obtained their liberation decades ago, seemingly western cultural imperialism still dominates and plagues the African psyche; hence they largely look to the West and ways of the West for established and emergent theoretical conceptions. This thesis aims to interrogate popular western literary theories unquestioningly used to analyse African works, particularly feminism and post-colonial theory; furthermore, to show crucial factors not taken into account such as the evolving power dynamics in African societies, the role of the “sacred” or spirituality which often forms and informs the dynamics of the text, and lastly, based on the poetry of Nontsizi Mgqwetho, to advocate for the need for an African literary theory and put forward the essential tenets of such a theory. The poetry of Xhosa poet, Nontsizi Mgqwetho, is used to analyse the complexities and dynamics of African literary production written in African languages; her poetry is written in isiXhosa to a Xhosa audience, a far cry from the assumption that African literary texts are concerned with writing to the “centre” as post-colonial theorists claim. Her work explicitly provides Africans with an approach to overcome territorial and cultural imperialism; she sees within the African psyche and traditional values empowering modes of resistance against any type of domination and through her poetry illustrates meaningful ways that Africans can critically engage with and examine the positives and negatives of cultural exchange and or assimilation, and the effects thereof while at the same time remaining proudly Africa.
- Full Text:
- Date Issued: 2017
- Authors: Nxasana, Thulani
- Date: 2017
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/4547 , vital:20687
- Description: This thesis seeks to examine the ways in which Africans and African scholarship in particular have relied on the West to lead the way in scientific inquiry, theory and ways of approaching literary texts thus the stunting effects of this in the growth and development of uniquely African literary scholarship and theorising. In his seminal work, Decolonising the Mind, Wa Thiong’o (1987a) stresses that “...how we view ourselves, our environment even, is very much dependent on where we stand in relationship to imperialism in its colonial and neocolonial stages; that if we are to do anything about our individual and collective being today, then we have to coldly and consciously look at what imperialism has been doing to us and to our view of ourselves in the universe” (Wa Thiong’o, 1987a, p.88). Although most African countries obtained their liberation decades ago, seemingly western cultural imperialism still dominates and plagues the African psyche; hence they largely look to the West and ways of the West for established and emergent theoretical conceptions. This thesis aims to interrogate popular western literary theories unquestioningly used to analyse African works, particularly feminism and post-colonial theory; furthermore, to show crucial factors not taken into account such as the evolving power dynamics in African societies, the role of the “sacred” or spirituality which often forms and informs the dynamics of the text, and lastly, based on the poetry of Nontsizi Mgqwetho, to advocate for the need for an African literary theory and put forward the essential tenets of such a theory. The poetry of Xhosa poet, Nontsizi Mgqwetho, is used to analyse the complexities and dynamics of African literary production written in African languages; her poetry is written in isiXhosa to a Xhosa audience, a far cry from the assumption that African literary texts are concerned with writing to the “centre” as post-colonial theorists claim. Her work explicitly provides Africans with an approach to overcome territorial and cultural imperialism; she sees within the African psyche and traditional values empowering modes of resistance against any type of domination and through her poetry illustrates meaningful ways that Africans can critically engage with and examine the positives and negatives of cultural exchange and or assimilation, and the effects thereof while at the same time remaining proudly Africa.
- Full Text:
- Date Issued: 2017
Indigenous and traditional musics in the school classroom : a re-evaluation of the South African Indigenous African Music (IAM) curriculum
- Authors: McConnachie, Boudina
- Date: 2017
- Subjects: Ethnomusicology , Indigenous people -- Music , Music -- Instruction and study -- Africa , Music -- Instruction and study -- Curricula -- Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:21182 , http://hdl.handle.net/10962/6806
- Description: Musical ideals set by European standards and values, entrenched through colonial oppression and promoted by the continued veneration of Western culture need to be re-evaluated. Despite the intention of the ANC government, through the Department of Basic Education's Curriculum and Assessment Policy Statement music curricula, to integrate Indigenous Knowledge and musics into the South African classroom, evidence shows that opportunities to do so are not seized. With reference to the proclaimed values of an African sensibility in the model of the South African music education curriculum, the history of its development and the current pedagogical movement towards transformation in the production of knowledge and the inclusion of Indigenous Knowledge (IK), this thesis questions why teachers in government schools in South Africa are not executing the Indigenous African Music (IAM) syllabus in the CAPS FET music curriculum. Taking the history of music education and the development of curriculum models and frameworks into account, it interrogates what strategies could improve the application of the current music curriculum in government schools in South Africa. These questions are addressed in the thesis by way of a discussion of the music curriculum and what its praxis in the classroom reveals about its efficacy, through observations and personal experiences, the observations of teachers and student teachers, a comparison with the experience in Zimbabwe, and an analysis of the music curriculum as it is currently devised and implemented. Straddling three methodological approaches, namely the ethnographic, the autoethnographic and the action research approach this study finds that the CAPS FET music curriculum does provide realistic opportunities to engage with African Indigenous and traditional music. This, however, is dependent upon the training of the teacher, facilities available in the classroom and the prior knowledge of the learner. A fundamental flaw of this curriculum is the approach to practical assessment of Indigenous and traditional African musics and the lack of assessment criteria and practical guidelines. In addition, the findings suggest that the fault regarding implementation of the curriculum lies in the training of students (who become teachers) at tertiary level, where an integrated approach to skills development regarding Indigenous African music is suggested.
- Full Text:
- Date Issued: 2017
- Authors: McConnachie, Boudina
- Date: 2017
- Subjects: Ethnomusicology , Indigenous people -- Music , Music -- Instruction and study -- Africa , Music -- Instruction and study -- Curricula -- Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:21182 , http://hdl.handle.net/10962/6806
- Description: Musical ideals set by European standards and values, entrenched through colonial oppression and promoted by the continued veneration of Western culture need to be re-evaluated. Despite the intention of the ANC government, through the Department of Basic Education's Curriculum and Assessment Policy Statement music curricula, to integrate Indigenous Knowledge and musics into the South African classroom, evidence shows that opportunities to do so are not seized. With reference to the proclaimed values of an African sensibility in the model of the South African music education curriculum, the history of its development and the current pedagogical movement towards transformation in the production of knowledge and the inclusion of Indigenous Knowledge (IK), this thesis questions why teachers in government schools in South Africa are not executing the Indigenous African Music (IAM) syllabus in the CAPS FET music curriculum. Taking the history of music education and the development of curriculum models and frameworks into account, it interrogates what strategies could improve the application of the current music curriculum in government schools in South Africa. These questions are addressed in the thesis by way of a discussion of the music curriculum and what its praxis in the classroom reveals about its efficacy, through observations and personal experiences, the observations of teachers and student teachers, a comparison with the experience in Zimbabwe, and an analysis of the music curriculum as it is currently devised and implemented. Straddling three methodological approaches, namely the ethnographic, the autoethnographic and the action research approach this study finds that the CAPS FET music curriculum does provide realistic opportunities to engage with African Indigenous and traditional music. This, however, is dependent upon the training of the teacher, facilities available in the classroom and the prior knowledge of the learner. A fundamental flaw of this curriculum is the approach to practical assessment of Indigenous and traditional African musics and the lack of assessment criteria and practical guidelines. In addition, the findings suggest that the fault regarding implementation of the curriculum lies in the training of students (who become teachers) at tertiary level, where an integrated approach to skills development regarding Indigenous African music is suggested.
- Full Text:
- Date Issued: 2017
The medical profession and the universalisation of South African Health Care: analysing the response of Eastern Cape general practitioners to the National Health Insurance proposals
- Authors: Hannah, Bridget
- Date: 2017
- Subjects: Health insurance -- South Africa , Health insurance -- Government policy -- South Africa , Medical care, Cost of -- South Africa , National health insurance -- South Africa , Medical policy -- South Africa , Physicians -- South Africa -- Attitudes
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/6075 , vital:21029
- Description: In 2011, the Green Paper on National Health Insurance (NHI) in South Africa was released, committing the South African government to a 14-year plan to radically transform the currently inequitable health system towards providing comprehensive quality health care free at point of access to all citizens. The pursuit of universal health coverage (UHC) in South Africa forms part of a global aspiration to achieve more equitable healthcare delivery. One of the critical issues emerging from the Green Paper was how the NHI would be staffed. The NHI is unlikely to be adequately staffed without GPs but evidence suggests that private sector doctors have always been resistant to nationalisation or socialisation as a threat to their occupational power and professional status. The core work of this thesis is a study undertaken of 78 doctors in the Eastern Cape, focusing on private sector general practitioners (GPs), as the largest constituency of medical professionals in the country. The interview schedule was designed to gauge doctors' responses to the NHI, encourage discussion on their reactions to the reforms, and its implications in their view for private medical practice. The responses of the doctors are analysed through application of two theoretical themes, namely: (i) actor-centred policy creation, discussed through application of Walt and Gilson's (1994) shared focus on content, context, process and actors in the policy process, and (ii) the debate on medical professionalism, espoused by Freidson (1973, 1994) and argued against by Haug and Sussman (1969), and McKinlay (1972, 1993). Thus, if the process of policy making must take into account key actors in order to deliver a successful policy transition, what are the implications if these actors are actively excluded, or do not willingly cooperate? Does this indicate anything telling about the private sector's role to play in the pursuit of universal healthcare?
- Full Text:
- Date Issued: 2017
- Authors: Hannah, Bridget
- Date: 2017
- Subjects: Health insurance -- South Africa , Health insurance -- Government policy -- South Africa , Medical care, Cost of -- South Africa , National health insurance -- South Africa , Medical policy -- South Africa , Physicians -- South Africa -- Attitudes
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/6075 , vital:21029
- Description: In 2011, the Green Paper on National Health Insurance (NHI) in South Africa was released, committing the South African government to a 14-year plan to radically transform the currently inequitable health system towards providing comprehensive quality health care free at point of access to all citizens. The pursuit of universal health coverage (UHC) in South Africa forms part of a global aspiration to achieve more equitable healthcare delivery. One of the critical issues emerging from the Green Paper was how the NHI would be staffed. The NHI is unlikely to be adequately staffed without GPs but evidence suggests that private sector doctors have always been resistant to nationalisation or socialisation as a threat to their occupational power and professional status. The core work of this thesis is a study undertaken of 78 doctors in the Eastern Cape, focusing on private sector general practitioners (GPs), as the largest constituency of medical professionals in the country. The interview schedule was designed to gauge doctors' responses to the NHI, encourage discussion on their reactions to the reforms, and its implications in their view for private medical practice. The responses of the doctors are analysed through application of two theoretical themes, namely: (i) actor-centred policy creation, discussed through application of Walt and Gilson's (1994) shared focus on content, context, process and actors in the policy process, and (ii) the debate on medical professionalism, espoused by Freidson (1973, 1994) and argued against by Haug and Sussman (1969), and McKinlay (1972, 1993). Thus, if the process of policy making must take into account key actors in order to deliver a successful policy transition, what are the implications if these actors are actively excluded, or do not willingly cooperate? Does this indicate anything telling about the private sector's role to play in the pursuit of universal healthcare?
- Full Text:
- Date Issued: 2017
Chemical composition of leaf essential oils of Lantana camara varieties in South Africa and their effect on the behavioural preference of Falconia intermedia
- Authors: Ngxande-Koza, Samella W
- Date: 2017
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/4877 , vital:20739
- Description: Lantana camara L. (Verbenaceae) is one the most problematic invaders in South Africa invading forest edges, sand dunes, and shorelines by forming impenetrable thickets. Lantana camara invasions degrade natural biodiversity, reduce the value of land and consequently it has been a target for biological control, over the last 50 years in South Africa. Studies that have reported on chemical profile of Lantana camara have been conducted around the world but not in South Africa. Hence, the first aim of the current study was to identify the chemical baseline of L. camara varieties in the Eastern Cape, South Africa. Recent studies have shown that feeding by one of the agents released against L. camara, Falconia intermedia (Distant) (Hemiptera: Miridae), induces anti-herbivory response through increased leaf toughness and trichome density. A preliminary study conducted also reported the production of volatile chemicals by one variety, Whitney Farm, due to feeding by the mirids. Therefore, the second aim was to determine the induced changes in chemical compounds of L. camara varieties after feeding by F. intermedia. A third aim was to determine the effect these chemical compounds have on the behaviour of F. intermedia. To identify the chemical baseline of L. camara varieties, the essential oils of four L. camara varieties (East London, Port Alfred, Whitney Farm and Heather Glen) were analysed using gas chromatography mass spectrometry (GC-MS) and that resulted to the identification of 163 constitutive and 75 induced chemicals across the varieties tested. Lantana camara varieties showed different chemical classes but were highly dominated by terpenes. A great variation in the number of constitutive chemical compounds was found in all the varieties. There were 56 constitutive chemical compounds in the Whitney Farm variety, 41 in the East London variety, 36 in the Heather Glen variety and 30 in the Port Alfred variety. The Whitney Farm variety had the highest number (22) of unique constitutive chemicals identified when compared with other varieties. This indicates the chemical distinctiveness of the Whitney Farm variety from the other varieties. In the varieties tested, there were common chemical compounds identified in constitutive and induced (discussed below) states of the plants such as caryophyllene, hexane, naphthalene, copaene and a-caryophyllene. Besides naphthalene, the majority of chemical compounds in South African L. camara varieties were similar to compounds that have been identified across the world, suggesting that they are closely related. The expression of naphthalene in these varieties may be due to changes in the chemicals expressed over evolutionary time as predicted by the Novel Weapons Hypothesis. Amongst the varieties, a great variation in chemical compounds and their concentrations was shown in the induced states of the plants. The concentration of constitutive caryophyllene ranged from (3.13 - 15.7) %, to (4.02 - 11.10) % after feeding. The concentration of constitutive hexane ranged from (6.13 - 71.19) %, to (33.3 - 75.8) % after feeding. The concentration of constitutive naphthalene ranged from (0.21 - 4.79) %, to (0.92 - 2.11) % after feeding. The concentration of constitutive copaene ranged from (0.57 - 1.57) %, to (1.20 - 2.72) %. Lastly, the concentration of constitutive a-caryophyllene ranged from (1.18 - 9.03) %, to (0.78 - 5.48) % after feeding. The changes in chemical concentrations in lantana varieties indicated that feeding by the mirid on L. camara varieties causes an induction by either reducing or increasing the chemical concentrations. To determine the effect of the identified compounds on the behaviour of F. intermedia adults, olfactometer bioassays were conducted using a Y-tube technique. A significantly higher proportion of F. intermedia were attracted to undamaged leaves over damaged leaves and purified air. Undamaged leaves attracted 52 % of F. intermedia from the East London variety, 62.5 % from the Port Alfred variety, 56 % from the Whitney Farm variety, 58 % from the Lyndhurst variety and 54.5 % from the Heather Glen variety in dual choice trials versus damaged leaves. Furthermore, a significantly higher proportion of F. intermedia were attracted to damaged leaves over purified air. Damaged leaves attracted 67 % of F. intermedia from the East London variety, 67 % from the Port Alfred variety, 65.9 % from the Whitney Farm variety, 65.3 % from the Heather Glen variety and 64.5 % from the Lyndhurst variety. Olfactometer bioassays were also conducted using purified standard compounds of four chemical compounds identified from essential oils, hexane was used as a positive control as it is reported to be an insect attractant in literature. Hexane was highly attractive to the mirids compared to three standard compounds caryophyllene, caryophyllene oxide and naphthalene at the rate of 80 %, 73 % and 80 %, respectively. The standard compounds tested against F. intermedia are major compounds contained by L. camara varieties and they have proven to have a repellent effect. This may indicate that after feeding by F. intermedia, the major compounds expressed by the plant varieties repel F. intermedia contributing to the invasiveness of this weed. The increased expression of hexane and caryophyllene after feeding may also indicate increased attraction to some insects, opening up the potential for third trophic level interactions in varieties where this is the case. This is the first study on the chemical composition of essential oils of L. camara in South Africa. Therefore, we recommend that where appropriate chemical profile studies of the invasive alien plants should be considered during host specificity testing, and the vital role of chemical compounds on agent-weed interactions must be taken into consideration with other factors before and after the biological control agents are released.
- Full Text:
- Date Issued: 2017
- Authors: Ngxande-Koza, Samella W
- Date: 2017
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/4877 , vital:20739
- Description: Lantana camara L. (Verbenaceae) is one the most problematic invaders in South Africa invading forest edges, sand dunes, and shorelines by forming impenetrable thickets. Lantana camara invasions degrade natural biodiversity, reduce the value of land and consequently it has been a target for biological control, over the last 50 years in South Africa. Studies that have reported on chemical profile of Lantana camara have been conducted around the world but not in South Africa. Hence, the first aim of the current study was to identify the chemical baseline of L. camara varieties in the Eastern Cape, South Africa. Recent studies have shown that feeding by one of the agents released against L. camara, Falconia intermedia (Distant) (Hemiptera: Miridae), induces anti-herbivory response through increased leaf toughness and trichome density. A preliminary study conducted also reported the production of volatile chemicals by one variety, Whitney Farm, due to feeding by the mirids. Therefore, the second aim was to determine the induced changes in chemical compounds of L. camara varieties after feeding by F. intermedia. A third aim was to determine the effect these chemical compounds have on the behaviour of F. intermedia. To identify the chemical baseline of L. camara varieties, the essential oils of four L. camara varieties (East London, Port Alfred, Whitney Farm and Heather Glen) were analysed using gas chromatography mass spectrometry (GC-MS) and that resulted to the identification of 163 constitutive and 75 induced chemicals across the varieties tested. Lantana camara varieties showed different chemical classes but were highly dominated by terpenes. A great variation in the number of constitutive chemical compounds was found in all the varieties. There were 56 constitutive chemical compounds in the Whitney Farm variety, 41 in the East London variety, 36 in the Heather Glen variety and 30 in the Port Alfred variety. The Whitney Farm variety had the highest number (22) of unique constitutive chemicals identified when compared with other varieties. This indicates the chemical distinctiveness of the Whitney Farm variety from the other varieties. In the varieties tested, there were common chemical compounds identified in constitutive and induced (discussed below) states of the plants such as caryophyllene, hexane, naphthalene, copaene and a-caryophyllene. Besides naphthalene, the majority of chemical compounds in South African L. camara varieties were similar to compounds that have been identified across the world, suggesting that they are closely related. The expression of naphthalene in these varieties may be due to changes in the chemicals expressed over evolutionary time as predicted by the Novel Weapons Hypothesis. Amongst the varieties, a great variation in chemical compounds and their concentrations was shown in the induced states of the plants. The concentration of constitutive caryophyllene ranged from (3.13 - 15.7) %, to (4.02 - 11.10) % after feeding. The concentration of constitutive hexane ranged from (6.13 - 71.19) %, to (33.3 - 75.8) % after feeding. The concentration of constitutive naphthalene ranged from (0.21 - 4.79) %, to (0.92 - 2.11) % after feeding. The concentration of constitutive copaene ranged from (0.57 - 1.57) %, to (1.20 - 2.72) %. Lastly, the concentration of constitutive a-caryophyllene ranged from (1.18 - 9.03) %, to (0.78 - 5.48) % after feeding. The changes in chemical concentrations in lantana varieties indicated that feeding by the mirid on L. camara varieties causes an induction by either reducing or increasing the chemical concentrations. To determine the effect of the identified compounds on the behaviour of F. intermedia adults, olfactometer bioassays were conducted using a Y-tube technique. A significantly higher proportion of F. intermedia were attracted to undamaged leaves over damaged leaves and purified air. Undamaged leaves attracted 52 % of F. intermedia from the East London variety, 62.5 % from the Port Alfred variety, 56 % from the Whitney Farm variety, 58 % from the Lyndhurst variety and 54.5 % from the Heather Glen variety in dual choice trials versus damaged leaves. Furthermore, a significantly higher proportion of F. intermedia were attracted to damaged leaves over purified air. Damaged leaves attracted 67 % of F. intermedia from the East London variety, 67 % from the Port Alfred variety, 65.9 % from the Whitney Farm variety, 65.3 % from the Heather Glen variety and 64.5 % from the Lyndhurst variety. Olfactometer bioassays were also conducted using purified standard compounds of four chemical compounds identified from essential oils, hexane was used as a positive control as it is reported to be an insect attractant in literature. Hexane was highly attractive to the mirids compared to three standard compounds caryophyllene, caryophyllene oxide and naphthalene at the rate of 80 %, 73 % and 80 %, respectively. The standard compounds tested against F. intermedia are major compounds contained by L. camara varieties and they have proven to have a repellent effect. This may indicate that after feeding by F. intermedia, the major compounds expressed by the plant varieties repel F. intermedia contributing to the invasiveness of this weed. The increased expression of hexane and caryophyllene after feeding may also indicate increased attraction to some insects, opening up the potential for third trophic level interactions in varieties where this is the case. This is the first study on the chemical composition of essential oils of L. camara in South Africa. Therefore, we recommend that where appropriate chemical profile studies of the invasive alien plants should be considered during host specificity testing, and the vital role of chemical compounds on agent-weed interactions must be taken into consideration with other factors before and after the biological control agents are released.
- Full Text:
- Date Issued: 2017