Linguistic minorities in the South African context : the case of Tshivenda
- Authors: Luvhengo, Nkhangweleni
- Date: 2013
- Subjects: Indigenous African languages , Apartheid , Tshivenda , Minority languages , Development , Status , Multilingualism , Sesotho , isiZulu , Perceptions , Linguistic minorities -- Research -- South Africa , Venda language -- Research -- South Africa , Language policy -- Research -- South Africa , Multilingualism -- Research -- South Africa , Linguistic rights -- Research -- South Africa , Language and languages -- Political aspects
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: vital:3558 , http://hdl.handle.net/10962/d1001862
- Description: After many years of the oppressive apartheid government, the new democratic era came into being in 1994. Lot of policy changes came into being, including language policy. This new language policy of the post-apartheid era recognises eleven official languages which include the nine indigenous African languages which were previously recognised as regional languages in the different homelands. The present study investigates the progress of Tshivenda in terms of status and development since it was accorded the official status in South Africa. Literature investigating the status of Tshivenda is generally sparse. This study investigates the status of Tshivenda in South Africa to explore how minority languages which are also recognised as official languages are treated. In most multilingual countries, there are issues which affect the development of minority languages, but the South African situation is interesting in that some of the minority languages are recognised as official languages. This study is a comparative in nature. Firstly, the study compares the level of corpus planning and development in Tshivenda and other indigenous South African languages. Secondly, it compares how people use Tshivenda in a rural area of Lukalo Village where the language is not under pressure from other languages and in Cosmo City, an urban area in Gauteng where Tshivenda speakers come into contact with speakers of more dominant languages such as isiZulu and Sesotho. Language use in different domains like, media, education, government and the home is considered in order to establish how people use languages and the factors which influence their linguistic behaviours. The study also establishes the perceptions and attitudes of the speakers of Tshivenda as a minority and those of the speakers of other languages towards Tshivenda’s role in the different domains such as education and the media. This study was influenced by previous research (Alexander 1989, Webb 2002) which found out that during the apartheid period Tshivenda speakers used to disguise their identity by adopting dominant languages like isiZulu and Sesotho in Johannesburg. Accordingly, the present research wanted to establish how the language policy change in the democratic era has impacted on the confidence of Tshivenda speakers regarding themselves and their language. This study establishes that although Tshivenda is now an official language in post-apartheid South Africa, it still has features of underdevelopment and marginalization that are typically of unofficial minority languages. Translation, lexicographic and terminological work in this language still lags behind that of other indigenous South African languages and there is still a shortage of school textbooks and adult literature in this language. As a result, using the language in education, the media and other controlling domains is still quite challenging, although positive developments such as the teaching of the language at university level can be noted. The Tshivenda speakers generally have a positive attitude towards their language and seem prepared to learn and use it confidently as long its functional value is enhanced, which is currently not happening. As a result, some Tshivenda speakers still regard English as a more worthwhile language to learn at the expense of their language
- Full Text:
- Authors: Luvhengo, Nkhangweleni
- Date: 2013
- Subjects: Indigenous African languages , Apartheid , Tshivenda , Minority languages , Development , Status , Multilingualism , Sesotho , isiZulu , Perceptions , Linguistic minorities -- Research -- South Africa , Venda language -- Research -- South Africa , Language policy -- Research -- South Africa , Multilingualism -- Research -- South Africa , Linguistic rights -- Research -- South Africa , Language and languages -- Political aspects
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: vital:3558 , http://hdl.handle.net/10962/d1001862
- Description: After many years of the oppressive apartheid government, the new democratic era came into being in 1994. Lot of policy changes came into being, including language policy. This new language policy of the post-apartheid era recognises eleven official languages which include the nine indigenous African languages which were previously recognised as regional languages in the different homelands. The present study investigates the progress of Tshivenda in terms of status and development since it was accorded the official status in South Africa. Literature investigating the status of Tshivenda is generally sparse. This study investigates the status of Tshivenda in South Africa to explore how minority languages which are also recognised as official languages are treated. In most multilingual countries, there are issues which affect the development of minority languages, but the South African situation is interesting in that some of the minority languages are recognised as official languages. This study is a comparative in nature. Firstly, the study compares the level of corpus planning and development in Tshivenda and other indigenous South African languages. Secondly, it compares how people use Tshivenda in a rural area of Lukalo Village where the language is not under pressure from other languages and in Cosmo City, an urban area in Gauteng where Tshivenda speakers come into contact with speakers of more dominant languages such as isiZulu and Sesotho. Language use in different domains like, media, education, government and the home is considered in order to establish how people use languages and the factors which influence their linguistic behaviours. The study also establishes the perceptions and attitudes of the speakers of Tshivenda as a minority and those of the speakers of other languages towards Tshivenda’s role in the different domains such as education and the media. This study was influenced by previous research (Alexander 1989, Webb 2002) which found out that during the apartheid period Tshivenda speakers used to disguise their identity by adopting dominant languages like isiZulu and Sesotho in Johannesburg. Accordingly, the present research wanted to establish how the language policy change in the democratic era has impacted on the confidence of Tshivenda speakers regarding themselves and their language. This study establishes that although Tshivenda is now an official language in post-apartheid South Africa, it still has features of underdevelopment and marginalization that are typically of unofficial minority languages. Translation, lexicographic and terminological work in this language still lags behind that of other indigenous South African languages and there is still a shortage of school textbooks and adult literature in this language. As a result, using the language in education, the media and other controlling domains is still quite challenging, although positive developments such as the teaching of the language at university level can be noted. The Tshivenda speakers generally have a positive attitude towards their language and seem prepared to learn and use it confidently as long its functional value is enhanced, which is currently not happening. As a result, some Tshivenda speakers still regard English as a more worthwhile language to learn at the expense of their language
- Full Text:
Linking institutional and ecological provisions for wastewater treatment discharge in a rural municipality, Eastern Cape, South Africa
- Authors: Muller, Matthew Justin
- Date: 2013
- Subjects: Sewage disposal plants -- South Africa -- Sundays Estuary (Eastern Cape) , Sewage disposal -- Law and legislation -- South Africa , Sewage -- Environmental aspects -- South Africa , Water-supply -- South Africa -- Management , Sewage disposal in rivers, lakes, etc. -- South Africa -- Sundays Estuary (Eastern Cape) , Rivers -- Environmental aspects -- South Africa -- Sundays Estuary (Eastern Cape) , Rivers -- Regulation -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:6044 , http://hdl.handle.net/10962/d1013048
- Description: The Green Drop Certification Programme, launched in 2008 alongside the Blue Drop Certification Programme, aims to provide the Department of Water Affairs with a national overview of how municipalities and their individual wastewater treatment works (WWTW) are complying with licence conditions set by the National Water Act (NWA) (No. 36 of 1998; DWAF 1998) and the Water Services Act (No. 108 of 1997; DWAF 1998). By publishing the results of each municipality’s performance, the programme aims to ensure continuous improvement in the wastewater treatment sector through public pressure. The programme has been identified by this project as a necessary linking tool between the NWA and the Water Services Act to ensure protection and sustainable use of South Africa’s natural water resources. It does this through assisting municipalities to improve their wastewater treatment operations which in theory will lead to discharged effluent that is compliant with discharge licence conditions. These discharge licences form part of the NWA’s enforcement tool of Source Directed Controls (SDC) which help a water resource meet the ecological goals set for it as part of Resource Directed Measures (RDM). The link between meeting the required SDC and achieving the RDM goals has never been empirically tested. This project aimed to determine the present ecological condition of the Uie River, a tributary of the Sundays River which the Sundays River Valley Municipality (SRVM) discharges its domestic effluent into. It then determined whether the SRVM’s WWTW was complying with the General Standard licence conditions and what the impact of the effluent on the river was through the analysis of monthly biomonitoring, water chemistry and habitat data. Lastly, the project examined the effectiveness of the Green Drop Certification Programme in bringing about change in the SRVM’s wastewater treatment sector, which previously achieved a Green Drop score of 5.6 percent. It wanted to examine the underlying assumption that a WWTW which improves its Green Drop score will be discharging a better quality effluent that will help a water resource meets the RDM goals set for it. The Kirkwood WWTW did not have a discharge licence at the time of assessment and was thus assessed under the General Standard licence conditions. It was found that the Kirkwood WWTW was not complying with the General Standard discharge licence conditions in the Uie River. This was having a negative impact on the river health, mainly through high concentrations of Total Inorganic Nitrogen (TIN-N), orthophosphate and turbidity. The SRVM should see an improvement in its Green Drop score for the Kirkwood WWTW. However, the municipality showed no implementation of necessary programmes. Implementation of these programmes would help the SRVM meet the General Standard licence conditions (part of SDC) which would help the Uie River meet the RDM goals set for it.
- Full Text:
- Authors: Muller, Matthew Justin
- Date: 2013
- Subjects: Sewage disposal plants -- South Africa -- Sundays Estuary (Eastern Cape) , Sewage disposal -- Law and legislation -- South Africa , Sewage -- Environmental aspects -- South Africa , Water-supply -- South Africa -- Management , Sewage disposal in rivers, lakes, etc. -- South Africa -- Sundays Estuary (Eastern Cape) , Rivers -- Environmental aspects -- South Africa -- Sundays Estuary (Eastern Cape) , Rivers -- Regulation -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:6044 , http://hdl.handle.net/10962/d1013048
- Description: The Green Drop Certification Programme, launched in 2008 alongside the Blue Drop Certification Programme, aims to provide the Department of Water Affairs with a national overview of how municipalities and their individual wastewater treatment works (WWTW) are complying with licence conditions set by the National Water Act (NWA) (No. 36 of 1998; DWAF 1998) and the Water Services Act (No. 108 of 1997; DWAF 1998). By publishing the results of each municipality’s performance, the programme aims to ensure continuous improvement in the wastewater treatment sector through public pressure. The programme has been identified by this project as a necessary linking tool between the NWA and the Water Services Act to ensure protection and sustainable use of South Africa’s natural water resources. It does this through assisting municipalities to improve their wastewater treatment operations which in theory will lead to discharged effluent that is compliant with discharge licence conditions. These discharge licences form part of the NWA’s enforcement tool of Source Directed Controls (SDC) which help a water resource meet the ecological goals set for it as part of Resource Directed Measures (RDM). The link between meeting the required SDC and achieving the RDM goals has never been empirically tested. This project aimed to determine the present ecological condition of the Uie River, a tributary of the Sundays River which the Sundays River Valley Municipality (SRVM) discharges its domestic effluent into. It then determined whether the SRVM’s WWTW was complying with the General Standard licence conditions and what the impact of the effluent on the river was through the analysis of monthly biomonitoring, water chemistry and habitat data. Lastly, the project examined the effectiveness of the Green Drop Certification Programme in bringing about change in the SRVM’s wastewater treatment sector, which previously achieved a Green Drop score of 5.6 percent. It wanted to examine the underlying assumption that a WWTW which improves its Green Drop score will be discharging a better quality effluent that will help a water resource meets the RDM goals set for it. The Kirkwood WWTW did not have a discharge licence at the time of assessment and was thus assessed under the General Standard licence conditions. It was found that the Kirkwood WWTW was not complying with the General Standard discharge licence conditions in the Uie River. This was having a negative impact on the river health, mainly through high concentrations of Total Inorganic Nitrogen (TIN-N), orthophosphate and turbidity. The SRVM should see an improvement in its Green Drop score for the Kirkwood WWTW. However, the municipality showed no implementation of necessary programmes. Implementation of these programmes would help the SRVM meet the General Standard licence conditions (part of SDC) which would help the Uie River meet the RDM goals set for it.
- Full Text:
Livelihood and coping strategy changes along rural-urban continua with an emphasis on natural resources
- Authors: Evans, Michelle Leigh
- Date: 2013
- Subjects: Natural resources -- South Africa -- Queenstown Natural resources -- South Africa -- Phalaborwa Rural-urban divide -- South Africa -- Queenstown Rural-urban divide -- South Africa -- Phalaborwa Income -- South Africa -- Queenstown Income -- South Africa -- Phalaborwa Women heads of households -- South Africa -- Queenstown Women heads of households -- South Africa -- Phalaborwa Adjustment (Psychology)
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4731 , http://hdl.handle.net/10962/d1001958
- Description: Rapid urbanisation is one of the greatest challenges facing both developed and developing countries. Sub-Saharan Africa has historically been one of the least developed and least urbanised areas of the world. However, urbanisation is now occurring much more rapidly in countries that have lower levels of per capita income. Therefore, in the coming decades, urban population growth is expected to be more widespread in the developing countries of the world. Most research on the role of natural resources focuses on rural communities and little is known about the contribution these resources make along the rural-urban continuum in small and medium sized towns as well as the contribution to total livelihoods. This is because researchers and policy makers have often treated rural and urban areas and their residents as distinct entities that should be studied in isolation. This, however, is not a true reflection of household livelihoods which often include both rural and urban elements. This study therefore analysed the impact of urbanisation on livelihoods along a rural-urban continuum with an emphasis on natural resources in South Africa. The main characteristics as well as the livelihood portfolios of respondent households were investigated. Secondly, the coping strategies used by households along the rural-urban continuum were explored, and disaggregated according to the gender of the household head. Data were collected along the rural-urban continuum of two small towns, namely Queenstown, located in the Eastern Cape province and Phalaborwa, located in the Limpopo Province of South Africa. Sampling covered the town, peri-urban areas, townships and adjacent rural households. A standardised survey instrument was used to capture household details and livelihood activities and a total of 272 interviews were conducted. The rural areas near both towns were poorer than the township and urban areas with regards to assets, access to employment and annual household income across all cash and non-cash income streams. The engagement in land-based activities increased towards the rural areas. The use of natural resources, as well as the number of resources collected, increased along the continuum towards the rural areas, with 12.0% to 49.0% of urban households, 30.0% to 88.0% of township households and between 80.0% and 100.0% of rural households engaging in the use and collection of natural resources. While natural resource use and collection was lowest in the urban areas, a significant amount of resources were still collected by urban households. Income portfolios for all households were calculated to determine the direct-use value of wild natural capital to livelihoods as well as the contribution made from land (arable and livestock farming), welfare grants and employment. Employment, barring one exception in the rural areas of Phalaborwa, was the largest contributor in terms of mean annual income along the continuum in both towns, followed by grants and pensions in the township and rural areas. In Phalaborwa, however, wild natural capital was found to be the largest contributor to local livelihoods, contributing 48.0% of the mean annual income. Household portfolios become more diversified in the poorer, rural areas as well as in households headed by females. The main shocks reported along the continuum in both Queenstown and Phalaborwa were death in the family, followed by a loss of employment, which was concentrated in male-headed households. Coping strategies resulting in the attainment of cash income fast, such as borrowing money from friends/relatives and cashing in retirements savings were favoured over longer term strategies such as finding local wage employment. Female-headed households were found to rely significantly on social groups or clubs as a coping strategy, highlighting the importance of social capital and social relations in female-headed households
- Full Text:
- Authors: Evans, Michelle Leigh
- Date: 2013
- Subjects: Natural resources -- South Africa -- Queenstown Natural resources -- South Africa -- Phalaborwa Rural-urban divide -- South Africa -- Queenstown Rural-urban divide -- South Africa -- Phalaborwa Income -- South Africa -- Queenstown Income -- South Africa -- Phalaborwa Women heads of households -- South Africa -- Queenstown Women heads of households -- South Africa -- Phalaborwa Adjustment (Psychology)
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4731 , http://hdl.handle.net/10962/d1001958
- Description: Rapid urbanisation is one of the greatest challenges facing both developed and developing countries. Sub-Saharan Africa has historically been one of the least developed and least urbanised areas of the world. However, urbanisation is now occurring much more rapidly in countries that have lower levels of per capita income. Therefore, in the coming decades, urban population growth is expected to be more widespread in the developing countries of the world. Most research on the role of natural resources focuses on rural communities and little is known about the contribution these resources make along the rural-urban continuum in small and medium sized towns as well as the contribution to total livelihoods. This is because researchers and policy makers have often treated rural and urban areas and their residents as distinct entities that should be studied in isolation. This, however, is not a true reflection of household livelihoods which often include both rural and urban elements. This study therefore analysed the impact of urbanisation on livelihoods along a rural-urban continuum with an emphasis on natural resources in South Africa. The main characteristics as well as the livelihood portfolios of respondent households were investigated. Secondly, the coping strategies used by households along the rural-urban continuum were explored, and disaggregated according to the gender of the household head. Data were collected along the rural-urban continuum of two small towns, namely Queenstown, located in the Eastern Cape province and Phalaborwa, located in the Limpopo Province of South Africa. Sampling covered the town, peri-urban areas, townships and adjacent rural households. A standardised survey instrument was used to capture household details and livelihood activities and a total of 272 interviews were conducted. The rural areas near both towns were poorer than the township and urban areas with regards to assets, access to employment and annual household income across all cash and non-cash income streams. The engagement in land-based activities increased towards the rural areas. The use of natural resources, as well as the number of resources collected, increased along the continuum towards the rural areas, with 12.0% to 49.0% of urban households, 30.0% to 88.0% of township households and between 80.0% and 100.0% of rural households engaging in the use and collection of natural resources. While natural resource use and collection was lowest in the urban areas, a significant amount of resources were still collected by urban households. Income portfolios for all households were calculated to determine the direct-use value of wild natural capital to livelihoods as well as the contribution made from land (arable and livestock farming), welfare grants and employment. Employment, barring one exception in the rural areas of Phalaborwa, was the largest contributor in terms of mean annual income along the continuum in both towns, followed by grants and pensions in the township and rural areas. In Phalaborwa, however, wild natural capital was found to be the largest contributor to local livelihoods, contributing 48.0% of the mean annual income. Household portfolios become more diversified in the poorer, rural areas as well as in households headed by females. The main shocks reported along the continuum in both Queenstown and Phalaborwa were death in the family, followed by a loss of employment, which was concentrated in male-headed households. Coping strategies resulting in the attainment of cash income fast, such as borrowing money from friends/relatives and cashing in retirements savings were favoured over longer term strategies such as finding local wage employment. Female-headed households were found to rely significantly on social groups or clubs as a coping strategy, highlighting the importance of social capital and social relations in female-headed households
- Full Text:
Livelihoods and natural resource use along the rural-urban continuum
- Authors: Ward, Catherine Dale
- Date: 2013
- Subjects: Natural resources -- South Africa , Human ecology -- South Africa , Cities and towns -- Growth -- South Africa , Natural resources -- Management -- South Africa , Rural poor -- South Africa , Urban poor -- South Africa , Sustainable development -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4727 , http://hdl.handle.net/10962/d1001669 , Natural resources -- South Africa , Human ecology -- South Africa , Cities and towns -- Growth -- South Africa , Natural resources -- Management -- South Africa , Rural poor -- South Africa , Urban poor -- South Africa , Sustainable development -- South Africa
- Description: Over the last century, developing countries have undergone rapid urbanisation resulting in marked social, economic and environmental changes. Africa is the least urbanised continent in the world but trends indicate that it is also the most rapidly urbanising region, accompanied by rising urban poverty. Urbanisation processes are often most pronounced in smaller urban centres since they experience the most severe pressures of population growth. Little is known about the role natural resources play along the rural-urban continuum and even less is known about the contribution of these resources within an urban context, particularly in small urban centres. In many sub-Saharan African cities, urban agriculture (the informal production of food in urban areas) has been used as a strategy to cope with increasing poverty levels but its role remains widely debated and uncertain. This thesis seeks to analyse the impacts of urbanisation on livelihoods and natural resource use, including home gardening and the collection of wild resources, in two South African towns and data was collected along the rural-urban continuum in Queenstown (Eastern Cape province) and Phalaborwa (Limpopo Province). Practices and contributions associated with agriculture and wild resource use were found to be significantly higher in Phalaborwa and this could be attributed to favourable environmental conditions and accessibility to wild resources due to the surrounding Mopani Bushveld. Rural households in Queenstown and Phalaborwa were more reliant on natural resources than their urban counterparts, but still diverse and incorporated a number of land-based and cash income generating strategies. Urban households tended to rely on one primary cash income strategy such as wage employment or state grants. However, natural resources did appear to play a subtle role in urban settings and particularly in the townships, where exclusion of natural resource contributions saw poverty levels increase up to 5%. Home gardening was practised by a wide range of people and not restricted to any one income group and, not surprisingly, wealthy cultivators who had access to resources such as land, water and fertilizer enjoyed increased benefits such as high produce yields. The results obtained suggest that rural-urban dynamics are complex and natural resource use in local livelihoods is contextualised within environmental settings, social preferences and historical contexts. Increasing pressures from the influx of people into small urban centres calls for a better understanding to how these processes are affecting livelihoods and natural resources to ensure sustainable management in the future.
- Full Text:
- Authors: Ward, Catherine Dale
- Date: 2013
- Subjects: Natural resources -- South Africa , Human ecology -- South Africa , Cities and towns -- Growth -- South Africa , Natural resources -- Management -- South Africa , Rural poor -- South Africa , Urban poor -- South Africa , Sustainable development -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4727 , http://hdl.handle.net/10962/d1001669 , Natural resources -- South Africa , Human ecology -- South Africa , Cities and towns -- Growth -- South Africa , Natural resources -- Management -- South Africa , Rural poor -- South Africa , Urban poor -- South Africa , Sustainable development -- South Africa
- Description: Over the last century, developing countries have undergone rapid urbanisation resulting in marked social, economic and environmental changes. Africa is the least urbanised continent in the world but trends indicate that it is also the most rapidly urbanising region, accompanied by rising urban poverty. Urbanisation processes are often most pronounced in smaller urban centres since they experience the most severe pressures of population growth. Little is known about the role natural resources play along the rural-urban continuum and even less is known about the contribution of these resources within an urban context, particularly in small urban centres. In many sub-Saharan African cities, urban agriculture (the informal production of food in urban areas) has been used as a strategy to cope with increasing poverty levels but its role remains widely debated and uncertain. This thesis seeks to analyse the impacts of urbanisation on livelihoods and natural resource use, including home gardening and the collection of wild resources, in two South African towns and data was collected along the rural-urban continuum in Queenstown (Eastern Cape province) and Phalaborwa (Limpopo Province). Practices and contributions associated with agriculture and wild resource use were found to be significantly higher in Phalaborwa and this could be attributed to favourable environmental conditions and accessibility to wild resources due to the surrounding Mopani Bushveld. Rural households in Queenstown and Phalaborwa were more reliant on natural resources than their urban counterparts, but still diverse and incorporated a number of land-based and cash income generating strategies. Urban households tended to rely on one primary cash income strategy such as wage employment or state grants. However, natural resources did appear to play a subtle role in urban settings and particularly in the townships, where exclusion of natural resource contributions saw poverty levels increase up to 5%. Home gardening was practised by a wide range of people and not restricted to any one income group and, not surprisingly, wealthy cultivators who had access to resources such as land, water and fertilizer enjoyed increased benefits such as high produce yields. The results obtained suggest that rural-urban dynamics are complex and natural resource use in local livelihoods is contextualised within environmental settings, social preferences and historical contexts. Increasing pressures from the influx of people into small urban centres calls for a better understanding to how these processes are affecting livelihoods and natural resources to ensure sustainable management in the future.
- Full Text:
Local setting influences the quantity of household food waste in mid-sized South African towns
- Chakona, Gamuchirai, Shackleton, Charlie M
- Authors: Chakona, Gamuchirai , Shackleton, Charlie M
- Date: 2013
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/67289 , vital:29067 , https://doi.org/10.1371/journal.pone.0189407
- Description: publisher version , From Introduction: The world faces a food security challenge with approximately 868 million people undernourished and about two billion people suffering from the negative health consequences of micronutrient deficiencies [1]. Yet, at least one-third of food produced for human consumption is lost or wasted along the food chain between farm and fork [2–7]. Food waste refers to wholesome edible material intended for human consumption, arising at any point in the food supply chain that is instead discarded, lost, degraded or consumed by pests [8]. Food loss is defined as the decrease in food quantity or quality which makes it unfit for human consumption [9]. According to the European Commission [10], food waste is composed of raw or cooked food materials such as vegetable peelings, meat trimmings and spoiled or excess ingredients or prepared food as well as bones, carcasses and organs. However, food waste can be measured only for edible products that are directed to human consumption [6]. Food losses take place at production, postharvest and processing stages in the food supply chain and the food losses that occur at the end of the food chain (retail and final consumption) are called “food waste” [11]. In our study food waste refers to food losses that occur at the end of the food chain (final consumption at household or consumer level) which include edible products that are directed to human consumption and are discarded when not consumed for various reasons. It is related to consumers’ behaviour [6,11] and it includes food loss before, during or after meal preparation in the household. , The research was funded by VW foundation under the Livelihoods Urbanisation and Natural Resources in Africa (LUNA) project through Freiburg University, Germany. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of this manuscript
- Full Text:
- Authors: Chakona, Gamuchirai , Shackleton, Charlie M
- Date: 2013
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/67289 , vital:29067 , https://doi.org/10.1371/journal.pone.0189407
- Description: publisher version , From Introduction: The world faces a food security challenge with approximately 868 million people undernourished and about two billion people suffering from the negative health consequences of micronutrient deficiencies [1]. Yet, at least one-third of food produced for human consumption is lost or wasted along the food chain between farm and fork [2–7]. Food waste refers to wholesome edible material intended for human consumption, arising at any point in the food supply chain that is instead discarded, lost, degraded or consumed by pests [8]. Food loss is defined as the decrease in food quantity or quality which makes it unfit for human consumption [9]. According to the European Commission [10], food waste is composed of raw or cooked food materials such as vegetable peelings, meat trimmings and spoiled or excess ingredients or prepared food as well as bones, carcasses and organs. However, food waste can be measured only for edible products that are directed to human consumption [6]. Food losses take place at production, postharvest and processing stages in the food supply chain and the food losses that occur at the end of the food chain (retail and final consumption) are called “food waste” [11]. In our study food waste refers to food losses that occur at the end of the food chain (final consumption at household or consumer level) which include edible products that are directed to human consumption and are discarded when not consumed for various reasons. It is related to consumers’ behaviour [6,11] and it includes food loss before, during or after meal preparation in the household. , The research was funded by VW foundation under the Livelihoods Urbanisation and Natural Resources in Africa (LUNA) project through Freiburg University, Germany. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of this manuscript
- Full Text:
Log analysis aided by latent semantic mapping
- Authors: Buys, Stephanus
- Date: 2013 , 2013-04-14
- Subjects: Latent semantic indexing , Data mining , Computer networks -- Security measures , Computer hackers , Computer security
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4575 , http://hdl.handle.net/10962/d1002963 , Latent semantic indexing , Data mining , Computer networks -- Security measures , Computer hackers , Computer security
- Description: In an age of zero-day exploits and increased on-line attacks on computing infrastructure, operational security practitioners are becoming increasingly aware of the value of the information captured in log events. Analysis of these events is critical during incident response, forensic investigations related to network breaches, hacking attacks and data leaks. Such analysis has led to the discipline of Security Event Analysis, also known as Log Analysis. There are several challenges when dealing with events, foremost being the increased volumes at which events are often generated and stored. Furthermore, events are often captured as unstructured data, with very little consistency in the formats or contents of the events. In this environment, security analysts and implementers of Log Management (LM) or Security Information and Event Management (SIEM) systems face the daunting task of identifying, classifying and disambiguating massive volumes of events in order for security analysis and automation to proceed. Latent Semantic Mapping (LSM) is a proven paradigm shown to be an effective method of, among other things, enabling word clustering, document clustering, topic clustering and semantic inference. This research is an investigation into the practical application of LSM in the discipline of Security Event Analysis, showing the value of using LSM to assist practitioners in identifying types of events, classifying events as belonging to certain sources or technologies and disambiguating different events from each other. The culmination of this research presents adaptations to traditional natural language processing techniques that resulted in improved efficacy of LSM when dealing with Security Event Analysis. This research provides strong evidence supporting the wider adoption and use of LSM, as well as further investigation into Security Event Analysis assisted by LSM and other natural language or computer-learning processing techniques. , LaTeX with hyperref package , Adobe Acrobat 9.54 Paper Capture Plug-in
- Full Text:
- Authors: Buys, Stephanus
- Date: 2013 , 2013-04-14
- Subjects: Latent semantic indexing , Data mining , Computer networks -- Security measures , Computer hackers , Computer security
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4575 , http://hdl.handle.net/10962/d1002963 , Latent semantic indexing , Data mining , Computer networks -- Security measures , Computer hackers , Computer security
- Description: In an age of zero-day exploits and increased on-line attacks on computing infrastructure, operational security practitioners are becoming increasingly aware of the value of the information captured in log events. Analysis of these events is critical during incident response, forensic investigations related to network breaches, hacking attacks and data leaks. Such analysis has led to the discipline of Security Event Analysis, also known as Log Analysis. There are several challenges when dealing with events, foremost being the increased volumes at which events are often generated and stored. Furthermore, events are often captured as unstructured data, with very little consistency in the formats or contents of the events. In this environment, security analysts and implementers of Log Management (LM) or Security Information and Event Management (SIEM) systems face the daunting task of identifying, classifying and disambiguating massive volumes of events in order for security analysis and automation to proceed. Latent Semantic Mapping (LSM) is a proven paradigm shown to be an effective method of, among other things, enabling word clustering, document clustering, topic clustering and semantic inference. This research is an investigation into the practical application of LSM in the discipline of Security Event Analysis, showing the value of using LSM to assist practitioners in identifying types of events, classifying events as belonging to certain sources or technologies and disambiguating different events from each other. The culmination of this research presents adaptations to traditional natural language processing techniques that resulted in improved efficacy of LSM when dealing with Security Event Analysis. This research provides strong evidence supporting the wider adoption and use of LSM, as well as further investigation into Security Event Analysis assisted by LSM and other natural language or computer-learning processing techniques. , LaTeX with hyperref package , Adobe Acrobat 9.54 Paper Capture Plug-in
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Low symmetry metallophthalocyanines and their nanoparticle conjugates for photodynamic antimicrobial chemotherapy
- Authors: Masilela, Nkosiphile
- Date: 2013
- Subjects: Nanoparticles Anti-infective agents Chemotherapy Photochemotherapy Quantum dots Gold Silver , Phthalocyanines
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4278 , http://hdl.handle.net/10962/d1001906
- Description: This thesis reports on the syntheses of novel low symmetrically substituted Zn, Sn, Ge and Ti MPc complexes containing a single carboxylic or cysteinyl group available for attachments to MNPs. The complexes were extensively characterized by various techniques to ensure their purity. Various metallic nanoparticles consisting of silver (AgNPs), gold (AuNPs) as well as quantum dots (QDs) were successfully prepared and conjugated to the low symmetry phthalocyanine complexes. The conjugates were successfully characterized using many techniques. The Q-band maxima of the MPcs were observed at completely different wavelength regions depending on the nature of the substituents and the central metal used. Blue shifting of the Q band in the absorption spectra was observed for the complexes in the presence of AuNPs, while aggregation was observed in the presence of quantum dots. The complexes were successfully electrospun into polymer fibers for the antimicrobial inhibition of bacteria. The photophysical and photochemical properties of these complexes were extensively investigated. Higher triplet and singlet oxygen quantum yields were achieved for the Ge Pc complexes, with all the complexes giving reasonable singlet oxygen quantum yields. An enhancement in triplet and singlet oxygen quantum yields was observed for all the complexes in the presence of metal nanoparticles. However, the singlet oxygen quantum yields decreased for all the complexes when incorporated into electrospun fibers. The antimicrobial behaviour of the complexes was investigated against Bacillus Subtilis and Staphylococcus Aureus in solution and in the fiber matrix. High antimicrobial inhibitions were observed for the Ge complexes followed by the ZnPc derivatives. All the low symmetry ZnPc derivatives were conjugated to AgNPs and their antimicrobial behaviour was compared to their symmetrical counterparts. The best antimicrobial inhibition behaviour was observed for the low symmetry Pcs when compared to their symmetrical counterparts. In the absence and in the presence of AgNPs, axially ligated SiPc also showed better antimicrobial activity when it was compared to the unsubstituted ZnPc complex.
- Full Text:
- Authors: Masilela, Nkosiphile
- Date: 2013
- Subjects: Nanoparticles Anti-infective agents Chemotherapy Photochemotherapy Quantum dots Gold Silver , Phthalocyanines
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4278 , http://hdl.handle.net/10962/d1001906
- Description: This thesis reports on the syntheses of novel low symmetrically substituted Zn, Sn, Ge and Ti MPc complexes containing a single carboxylic or cysteinyl group available for attachments to MNPs. The complexes were extensively characterized by various techniques to ensure their purity. Various metallic nanoparticles consisting of silver (AgNPs), gold (AuNPs) as well as quantum dots (QDs) were successfully prepared and conjugated to the low symmetry phthalocyanine complexes. The conjugates were successfully characterized using many techniques. The Q-band maxima of the MPcs were observed at completely different wavelength regions depending on the nature of the substituents and the central metal used. Blue shifting of the Q band in the absorption spectra was observed for the complexes in the presence of AuNPs, while aggregation was observed in the presence of quantum dots. The complexes were successfully electrospun into polymer fibers for the antimicrobial inhibition of bacteria. The photophysical and photochemical properties of these complexes were extensively investigated. Higher triplet and singlet oxygen quantum yields were achieved for the Ge Pc complexes, with all the complexes giving reasonable singlet oxygen quantum yields. An enhancement in triplet and singlet oxygen quantum yields was observed for all the complexes in the presence of metal nanoparticles. However, the singlet oxygen quantum yields decreased for all the complexes when incorporated into electrospun fibers. The antimicrobial behaviour of the complexes was investigated against Bacillus Subtilis and Staphylococcus Aureus in solution and in the fiber matrix. High antimicrobial inhibitions were observed for the Ge complexes followed by the ZnPc derivatives. All the low symmetry ZnPc derivatives were conjugated to AgNPs and their antimicrobial behaviour was compared to their symmetrical counterparts. The best antimicrobial inhibition behaviour was observed for the low symmetry Pcs when compared to their symmetrical counterparts. In the absence and in the presence of AgNPs, axially ligated SiPc also showed better antimicrobial activity when it was compared to the unsubstituted ZnPc complex.
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Lʹétude des thèmes du deuil et de la marginalité dans Le Royaume Aveugle et Reine Pokou, concerto pour un sacrifice de Véronique Tadjo
- Sachikonye, Tsitsi Shamiso Anne
- Authors: Sachikonye, Tsitsi Shamiso Anne
- Date: 2013
- Subjects: Tadjo, Véronique -- Criticism and interpretation , West African literature (French) -- History and criticism , African fiction (French) -- 20th century
- Language: French
- Type: Thesis , Masters , MSocSc
- Identifier: vital:3603 , http://hdl.handle.net/10962/d1002956 , Tadjo, Véronique -- Criticism and interpretation , West African literature (French) -- History and criticism , African fiction (French) -- 20th century
- Description: The field of our study is Francophone African Literature and this thesis explores the themes of marginality and grief both experienced by Princess Akissi in The Blind Kingdom and Princess Pokou in Queen Pokou (2004) during their rise to power in their respective kingdoms. The two novels written by Véronique Tadjo from Ivory Coast, are subjected to thematic analysis because they are both based on similar storylines - that of conflict and rivalry within kingdoms resulting in the exile of the two princesses. One of the novels is set in a pre-colonial period while the other is set in a postcolonial era. Queen Pokou, winner of the 2005 Grand Prix Littéraire d’Afrique Noire (which is the most distinguished prize in Francophone African literature), is a retelling of the founding myths of the Baoulé people of Ivory Coast. In her literary texts, Tadjo transgresses the original legend and her reconstruction of this legend is significant because it challenges the ritual sacrifice made by Princess Pokou in order to free her people and to become queen. In The Blind Kingdom (1990), Tadjo highlights the corruption and injustice of the ruling elite. Space is used to reinforce the King’s domination thus a revolution is necessary to overthrow the exploitative power structures in place. The revolution that takes place relies heavily on the participation of Karim and especially on Princess Akissi who chooses to rebel against her father, King Ato IV in order to stop injustice. This thematic analysis, supported by semiotic theory, aims to establish and demonstrate the relationship between marginality of the two princesses, in particular, and their subsequent grief. It sheds light on the reasons for their exclusion from power as well as the nature of the conflicts that occur as they rise to power. The study postulates that certain myths and images are evoked by the novelist to symbolise the exclusion of the two princesses from power.
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- Authors: Sachikonye, Tsitsi Shamiso Anne
- Date: 2013
- Subjects: Tadjo, Véronique -- Criticism and interpretation , West African literature (French) -- History and criticism , African fiction (French) -- 20th century
- Language: French
- Type: Thesis , Masters , MSocSc
- Identifier: vital:3603 , http://hdl.handle.net/10962/d1002956 , Tadjo, Véronique -- Criticism and interpretation , West African literature (French) -- History and criticism , African fiction (French) -- 20th century
- Description: The field of our study is Francophone African Literature and this thesis explores the themes of marginality and grief both experienced by Princess Akissi in The Blind Kingdom and Princess Pokou in Queen Pokou (2004) during their rise to power in their respective kingdoms. The two novels written by Véronique Tadjo from Ivory Coast, are subjected to thematic analysis because they are both based on similar storylines - that of conflict and rivalry within kingdoms resulting in the exile of the two princesses. One of the novels is set in a pre-colonial period while the other is set in a postcolonial era. Queen Pokou, winner of the 2005 Grand Prix Littéraire d’Afrique Noire (which is the most distinguished prize in Francophone African literature), is a retelling of the founding myths of the Baoulé people of Ivory Coast. In her literary texts, Tadjo transgresses the original legend and her reconstruction of this legend is significant because it challenges the ritual sacrifice made by Princess Pokou in order to free her people and to become queen. In The Blind Kingdom (1990), Tadjo highlights the corruption and injustice of the ruling elite. Space is used to reinforce the King’s domination thus a revolution is necessary to overthrow the exploitative power structures in place. The revolution that takes place relies heavily on the participation of Karim and especially on Princess Akissi who chooses to rebel against her father, King Ato IV in order to stop injustice. This thematic analysis, supported by semiotic theory, aims to establish and demonstrate the relationship between marginality of the two princesses, in particular, and their subsequent grief. It sheds light on the reasons for their exclusion from power as well as the nature of the conflicts that occur as they rise to power. The study postulates that certain myths and images are evoked by the novelist to symbolise the exclusion of the two princesses from power.
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Mathematics teachers' experiences of designing and implementing a circle geometry teaching programme using the van Hiele phases of instruction as a conceptual framework: a Namibian case study
- Authors: Dongwi, Beata Lididimikeni
- Date: 2013
- Subjects: Geometry -- Study and teaching (Secondary) -- Namibia Mathematics -- Study and teaching -- Namibia
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1412 , http://hdl.handle.net/10962/d1003133
- Description: The aim of this case study was to examine, analyze and report on the findings of the experiences of selected mathematics teachers when they used the van Hiele phases of instruction in designing and implementing a Grade 11 circle geometry teaching programme. The sample consisted of three selected mathematics teachers from the school where the researcher teaches. This school is located in the Oshikoto Education Region in Namibia. The school serves a multicultural group of 759 learners from a middle-class economic background. The site and participants were selected conveniently as the researcher had unrestricted access to both the facilities and the participants. This research takes the form of a case study and is underpinned by the interpretive paradigm. Data for this research was collected using a variety of techniques such as interviews, classroom observation and document analysis. This facilitated easy triangulation of the data. The findings of this research make four claims with regard to the experiences of the mathematics teachers with designing and implementing the circle geometry teaching programme using the five van Hiele phases of instruction as a conceptual framework. The findings revealed that firstly, all three participating mathematics teachers used and implemented all the five van Hiele phases of instruction in their lessons I observed. Secondly, the teachers navigated quite freely from one phase of instruction to the next, but also returned to the earlier phases for clarification and reinforcement in their teaching. Thirdly, the teachers saw the phases of instruction as a good pedagogical tool or template for planning and presenting lessons. Fourthly, the majority of the learners followed the instructions and seemed to obtain the answers faster than expected. The lesson presentations were lively and both teachers and learners communicated at length to discover angle properties of circles while developing and nurturing the technical language of geometry.
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- Authors: Dongwi, Beata Lididimikeni
- Date: 2013
- Subjects: Geometry -- Study and teaching (Secondary) -- Namibia Mathematics -- Study and teaching -- Namibia
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1412 , http://hdl.handle.net/10962/d1003133
- Description: The aim of this case study was to examine, analyze and report on the findings of the experiences of selected mathematics teachers when they used the van Hiele phases of instruction in designing and implementing a Grade 11 circle geometry teaching programme. The sample consisted of three selected mathematics teachers from the school where the researcher teaches. This school is located in the Oshikoto Education Region in Namibia. The school serves a multicultural group of 759 learners from a middle-class economic background. The site and participants were selected conveniently as the researcher had unrestricted access to both the facilities and the participants. This research takes the form of a case study and is underpinned by the interpretive paradigm. Data for this research was collected using a variety of techniques such as interviews, classroom observation and document analysis. This facilitated easy triangulation of the data. The findings of this research make four claims with regard to the experiences of the mathematics teachers with designing and implementing the circle geometry teaching programme using the five van Hiele phases of instruction as a conceptual framework. The findings revealed that firstly, all three participating mathematics teachers used and implemented all the five van Hiele phases of instruction in their lessons I observed. Secondly, the teachers navigated quite freely from one phase of instruction to the next, but also returned to the earlier phases for clarification and reinforcement in their teaching. Thirdly, the teachers saw the phases of instruction as a good pedagogical tool or template for planning and presenting lessons. Fourthly, the majority of the learners followed the instructions and seemed to obtain the answers faster than expected. The lesson presentations were lively and both teachers and learners communicated at length to discover angle properties of circles while developing and nurturing the technical language of geometry.
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Mechanisms of luminescence in α-Al₂O₃:C : investigations using time-resolved optical stimulation and thermoluminescence techniques
- Authors: Nyirenda, Angel Newton
- Date: 2013
- Subjects: Thermoluminescence Aluminum oxide Optically stimulated luminescence dating Radiation dosimetry
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5447 , http://hdl.handle.net/10962/d1002961
- Description: Carbon-doped aluminium oxide, α-Al₂O₃:C, is a ultra-sensitive dosimeter of topical research interest. The aim of this project was to investigate the dynamics of luminesce in this material. The methods of investigation consisted of thermoluminescence and time-resolved optical stimulation. Thermoluminescence measurements provide information on trap distribution and kinetic parameters of the traps involved in luminescence whereas time-resolved optical stimulation is a handy technique in investigation of luminescence lifetimes and provides an insight into the charge transitions between traps and recombination centres. Measurements were made on samples annealed at a nominal temperature of 900⁰C for 15 minutes. The material shows the presence of five thermoluminescence peaks at 37⁰C, 160⁰C, 300⁰C 410⁰C, and 480⁰C at a heating rate of 0.03k/s when irradiated to 6.0 Gy of beta. The main peak at 160⁰C, shows a linear dose response for doses between 0.1 Gy and 10 Gy and then goes sublinear above 10 Gy, the peak at 37⁰C shows a sublinear dose response for doses between 0.1 Gy and 10 Gy and appears to saturate thereafter, whereas the dose response of the peak at 300⁰C goes from linear to supralinear then apparently quadratic behaviour in the dose range of 0.1 Gy to 16.0 Gy. The trap depth of the main peak, that is, its activation energy as determined below the conduction band, has been approximated at 1.3 eV with a kinetic order of approximately 1.2. Time-resolved optical stimulation has been used to investigate luminescence lifetimes. The mean luminescence lifetime obtained for the sample at ambient temperatures is 35.0±1.0 ms. The investigations of the dependence of luminescence lifetimes on measurement temperature show that the material suffers from thermal quenching effects at measurement temperatures above 140⁰C with the activation energy of thermal quenching estimated at 1.045±0.002 eV. Shallow traps i.e. traps lying close to the conduction band, seem to elongate the lifetimes of optically stimulated luminescence in the material at temperatures between 30⁰C - 80⁰C due to charge retrapping. The material exhibits both fading and recuperation of the optically stimulated luminescence signal with storage time.
- Full Text:
- Authors: Nyirenda, Angel Newton
- Date: 2013
- Subjects: Thermoluminescence Aluminum oxide Optically stimulated luminescence dating Radiation dosimetry
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5447 , http://hdl.handle.net/10962/d1002961
- Description: Carbon-doped aluminium oxide, α-Al₂O₃:C, is a ultra-sensitive dosimeter of topical research interest. The aim of this project was to investigate the dynamics of luminesce in this material. The methods of investigation consisted of thermoluminescence and time-resolved optical stimulation. Thermoluminescence measurements provide information on trap distribution and kinetic parameters of the traps involved in luminescence whereas time-resolved optical stimulation is a handy technique in investigation of luminescence lifetimes and provides an insight into the charge transitions between traps and recombination centres. Measurements were made on samples annealed at a nominal temperature of 900⁰C for 15 minutes. The material shows the presence of five thermoluminescence peaks at 37⁰C, 160⁰C, 300⁰C 410⁰C, and 480⁰C at a heating rate of 0.03k/s when irradiated to 6.0 Gy of beta. The main peak at 160⁰C, shows a linear dose response for doses between 0.1 Gy and 10 Gy and then goes sublinear above 10 Gy, the peak at 37⁰C shows a sublinear dose response for doses between 0.1 Gy and 10 Gy and appears to saturate thereafter, whereas the dose response of the peak at 300⁰C goes from linear to supralinear then apparently quadratic behaviour in the dose range of 0.1 Gy to 16.0 Gy. The trap depth of the main peak, that is, its activation energy as determined below the conduction band, has been approximated at 1.3 eV with a kinetic order of approximately 1.2. Time-resolved optical stimulation has been used to investigate luminescence lifetimes. The mean luminescence lifetime obtained for the sample at ambient temperatures is 35.0±1.0 ms. The investigations of the dependence of luminescence lifetimes on measurement temperature show that the material suffers from thermal quenching effects at measurement temperatures above 140⁰C with the activation energy of thermal quenching estimated at 1.045±0.002 eV. Shallow traps i.e. traps lying close to the conduction band, seem to elongate the lifetimes of optically stimulated luminescence in the material at temperatures between 30⁰C - 80⁰C due to charge retrapping. The material exhibits both fading and recuperation of the optically stimulated luminescence signal with storage time.
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Microsatellite and morphometric analysis of chokka squid (Loligo reynaudi) from different spawning aggregations around the South African coast
- Authors: Stonier, Terence Anthony
- Date: 2013
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5344 , http://hdl.handle.net/10962/d1006779
- Description: Accurate information on stock structure is very important to the effective management of any commercially exploited species (Angel et al. 1994), particularly in annual species like Loligo reynaudi. Previous molecular work on a number of fish and cephalopod species has shown that stock structuring may be more complex than originally believed and while much scientific work has been conducted on Loligo reynaudi to date, molecular work has been lacking and this species’ fishery is currently managed as a single stock. The primary aim of this project was to examine the population genetics of Loligo reynaudi on a molecular level, by looking at the levels of genetic variation between different spawning aggregations along the inshore distribution of the chokka squid, with particular attention being paid to any variation between Eastern Cape and Agulhas Bank groups. The secondary aim was to conduct a morphological analysis on samples from the same major areas in order to see if any genetic variation observed would be complemented by phenotypic variation. Two separate sample sets were collected; Genetic samples were collected from 6 different spawning sites along the South African Coast between April and July, 2006 and whole individuals for morphometric analysis were collected from 4 spawning sites between April and July 2007. Samples were screened for genetic variation between different spawning aggregations along the inshore distribution of chokka squid, from Port Alfred in the Eastern Cape, to the western Agulhas Bank. After this a morphometric analysis on samples from the same major areas, Eastern Cape, Agulhas Bank and Angola, was carried out. Genetic results showed significant variation between some of the sample groups. As expected, the Angolan outgroup consistently showed significant variation from other samples, while there was evidence of differentiation between the South African samples themselves. These results could have implications for the previously documented life cycle model of Loligo reynaudi and provide a basis for further study at a finer resolution into where exactly the boundaries of these different groupings can be found. This stock structuring has implications for the management of the species and warrants further genetic research with microsatellites proving to be a powerful tool in the explanation of stock structuring. Unfortunately, due to possible errors in taking measurements, morphometric analysis did not yield useful results which can be described and interpreted in this study. It is felt that further genetic study conducted on a finer scale, should be accompanied by a repeat of the morphometric analysis.
- Full Text:
- Authors: Stonier, Terence Anthony
- Date: 2013
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5344 , http://hdl.handle.net/10962/d1006779
- Description: Accurate information on stock structure is very important to the effective management of any commercially exploited species (Angel et al. 1994), particularly in annual species like Loligo reynaudi. Previous molecular work on a number of fish and cephalopod species has shown that stock structuring may be more complex than originally believed and while much scientific work has been conducted on Loligo reynaudi to date, molecular work has been lacking and this species’ fishery is currently managed as a single stock. The primary aim of this project was to examine the population genetics of Loligo reynaudi on a molecular level, by looking at the levels of genetic variation between different spawning aggregations along the inshore distribution of the chokka squid, with particular attention being paid to any variation between Eastern Cape and Agulhas Bank groups. The secondary aim was to conduct a morphological analysis on samples from the same major areas in order to see if any genetic variation observed would be complemented by phenotypic variation. Two separate sample sets were collected; Genetic samples were collected from 6 different spawning sites along the South African Coast between April and July, 2006 and whole individuals for morphometric analysis were collected from 4 spawning sites between April and July 2007. Samples were screened for genetic variation between different spawning aggregations along the inshore distribution of chokka squid, from Port Alfred in the Eastern Cape, to the western Agulhas Bank. After this a morphometric analysis on samples from the same major areas, Eastern Cape, Agulhas Bank and Angola, was carried out. Genetic results showed significant variation between some of the sample groups. As expected, the Angolan outgroup consistently showed significant variation from other samples, while there was evidence of differentiation between the South African samples themselves. These results could have implications for the previously documented life cycle model of Loligo reynaudi and provide a basis for further study at a finer resolution into where exactly the boundaries of these different groupings can be found. This stock structuring has implications for the management of the species and warrants further genetic research with microsatellites proving to be a powerful tool in the explanation of stock structuring. Unfortunately, due to possible errors in taking measurements, morphometric analysis did not yield useful results which can be described and interpreted in this study. It is felt that further genetic study conducted on a finer scale, should be accompanied by a repeat of the morphometric analysis.
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Modelling stock return volatility dynamics in selected African markets
- Authors: King, Daniel Jonathan
- Date: 2013
- Subjects: Rate of return -- Africa Stocks -- Prices -- Africa Finance -- Developing countries -- Econometric models
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:1051 , http://hdl.handle.net/10962/d1006452
- Description: Stock return volatility has been shown to occasionally exhibit discrete structural shifts. These shifts are particularly evident in the transition from ‘normal’ to crisis periods, and tend to be more pronounced in developing markets. This study aims to establish whether accounting for structural changes in the conditional variance process, through the use of Markov-switching models, improves estimates and forecasts of stock return volatility over those of the more conventional single-state (G)ARCH models, within and across selected African markets for the period 2002-2012. In the univariate portion of the study, the performances of various Markov-switching models are tested against a single-state benchmark model through the use of in-sample goodness-of-fit and predictive ability measures. In the multivariate context, the single-state and Markov-switching models are comparatively assessed according to their usefulness in constructing optimal stock portfolios. It is found that, even after accounting for structural breaks in the conditional variance process, conventional GARCH effects remain important to capturing the heteroscedasticity evident in the data. However, those univariate models which include a GARCH term are shown to perform comparatively poorly when used for forecasting purposes. Additionally, in the multivariate study, the use of Markov-switching variance-covariance estimates improves risk-adjusted portfolio returns when compared to portfolios that are constructed using the more conventional single-state models. While there is evidence that the use of some Markov-switching models can result in better forecasts and higher risk-adjusted returns than those models which include GARCH effects, the inability of the simpler Markov-switching models to fully capture the heteroscedasticity in the data remains problematic.
- Full Text:
- Authors: King, Daniel Jonathan
- Date: 2013
- Subjects: Rate of return -- Africa Stocks -- Prices -- Africa Finance -- Developing countries -- Econometric models
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:1051 , http://hdl.handle.net/10962/d1006452
- Description: Stock return volatility has been shown to occasionally exhibit discrete structural shifts. These shifts are particularly evident in the transition from ‘normal’ to crisis periods, and tend to be more pronounced in developing markets. This study aims to establish whether accounting for structural changes in the conditional variance process, through the use of Markov-switching models, improves estimates and forecasts of stock return volatility over those of the more conventional single-state (G)ARCH models, within and across selected African markets for the period 2002-2012. In the univariate portion of the study, the performances of various Markov-switching models are tested against a single-state benchmark model through the use of in-sample goodness-of-fit and predictive ability measures. In the multivariate context, the single-state and Markov-switching models are comparatively assessed according to their usefulness in constructing optimal stock portfolios. It is found that, even after accounting for structural breaks in the conditional variance process, conventional GARCH effects remain important to capturing the heteroscedasticity evident in the data. However, those univariate models which include a GARCH term are shown to perform comparatively poorly when used for forecasting purposes. Additionally, in the multivariate study, the use of Markov-switching variance-covariance estimates improves risk-adjusted portfolio returns when compared to portfolios that are constructed using the more conventional single-state models. While there is evidence that the use of some Markov-switching models can result in better forecasts and higher risk-adjusted returns than those models which include GARCH effects, the inability of the simpler Markov-switching models to fully capture the heteroscedasticity in the data remains problematic.
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Modulation of Plasmodium falciparum chaperones PfHsp70-1 and PfHsp70-x by small molecules
- Authors: Cockburn, Ingrid Louise
- Date: 2013
- Subjects: Plasmodium falciparum Heat shock proteins Molecular chaperones Homeostasis Protein folding Malaria Antimalarials Escherichia coli
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3887 , http://hdl.handle.net/10962/d1001747
- Description: The heat shock proteins of ~ 70 kDa (Hsp70s) are a conserved group of molecular chaperones important in maintaining the protein homeostasis in cells, carrying out functions including refolding of misfolded or unfolded proteins. Hsp70s function in conjunction with a number of other proteins including Hsp40 cochaperones. Central to the regulation Hsp70 activity is the Hsp70 ATPase cycle, involving ATP hydrolysis by Hsp70, and stimulation of this ATP hydrolysis by Hsp40. PfHsp70-1, the major cytosolic Hsp70 in the malaria parasite, Plasmodium falciparum, and PfHsp70-x, a novel malarial Hsp70 recently found to be exported to the host cell cytosol during the erythrocytic stages of the P. falciparum lifecycle, are both thought to play important roles in the malaria parasite’s survival and virulence, and thus represent novel antimalarial targets. Modulation of the function of these proteins by small molecules could thus lead to the development of antimalarials with novel targets and mechanisms. In the present study, malarial Hsp70s (PfHsp70-1 and PfHsp70-x), human Hsp70 (HSPA1A), malarial Hsp40 (PfHsp40) and human Hsp40 (Hsj1a) were recombinantly produced in Escherichia coli. In a characterisation of the chaperone activity of recombinant PfHsp70-x, the protein was found to have a basal ATPase activity (15.7 nmol ATP/min/mg protein) comparable to that previously described for PfHsp70-1, and an aggregation suppression activity significantly higher than that of PfHsp70-1. In vitro assays were used to screen five compounds of interest (lapachol, bromo-β-lapachona and malonganenones A, B and C) belonging to two compound classes (1,4 naphthoquinones and prenylated alkaloids) for modulatory effects on PfHsp70-1, PfHsp70-x and HsHsp70. A wide range of effects by compounds on the chaperone activities of Hsp70s was observed, including differential effects by compounds on different Hsp70s despite high conservation (≥ 70 % sequence identity) between the Hsp70s. The five compounds were shown to interact with all three Hsp70s in in vitro binding studies. Differential modulation by compounds was observed between the Hsj1a-stimulated ATPase activities of different Hsp70s, suggestive of not only a high degree of specificity of compounds to chaperone systems, but also distinct interactions between different Hsp70s and Hjs1a. The effects of compounds on the survival of P. falciparum parasites as well as mammalian cells was assessed. Bromo-β-lapachona was found to have broad effects across all systems, modulating the chaperone activities of all three Hsp70s, and showing significant toxicity toward both P. falciparum parasites and mammalian cells in culture. Malonganenone A was found to modulate only the malarial Hsp70s, not human Hsp70, showing significant toxicity toward malarial parasites (IC₅₀ ~ 0.8 μM), and comparatively low toxicity toward mammalian cells, representing therefore a novel starting point for a new class of antimalarials potentially targeting a new antimalarial drug target, Hsp70.
- Full Text:
- Authors: Cockburn, Ingrid Louise
- Date: 2013
- Subjects: Plasmodium falciparum Heat shock proteins Molecular chaperones Homeostasis Protein folding Malaria Antimalarials Escherichia coli
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3887 , http://hdl.handle.net/10962/d1001747
- Description: The heat shock proteins of ~ 70 kDa (Hsp70s) are a conserved group of molecular chaperones important in maintaining the protein homeostasis in cells, carrying out functions including refolding of misfolded or unfolded proteins. Hsp70s function in conjunction with a number of other proteins including Hsp40 cochaperones. Central to the regulation Hsp70 activity is the Hsp70 ATPase cycle, involving ATP hydrolysis by Hsp70, and stimulation of this ATP hydrolysis by Hsp40. PfHsp70-1, the major cytosolic Hsp70 in the malaria parasite, Plasmodium falciparum, and PfHsp70-x, a novel malarial Hsp70 recently found to be exported to the host cell cytosol during the erythrocytic stages of the P. falciparum lifecycle, are both thought to play important roles in the malaria parasite’s survival and virulence, and thus represent novel antimalarial targets. Modulation of the function of these proteins by small molecules could thus lead to the development of antimalarials with novel targets and mechanisms. In the present study, malarial Hsp70s (PfHsp70-1 and PfHsp70-x), human Hsp70 (HSPA1A), malarial Hsp40 (PfHsp40) and human Hsp40 (Hsj1a) were recombinantly produced in Escherichia coli. In a characterisation of the chaperone activity of recombinant PfHsp70-x, the protein was found to have a basal ATPase activity (15.7 nmol ATP/min/mg protein) comparable to that previously described for PfHsp70-1, and an aggregation suppression activity significantly higher than that of PfHsp70-1. In vitro assays were used to screen five compounds of interest (lapachol, bromo-β-lapachona and malonganenones A, B and C) belonging to two compound classes (1,4 naphthoquinones and prenylated alkaloids) for modulatory effects on PfHsp70-1, PfHsp70-x and HsHsp70. A wide range of effects by compounds on the chaperone activities of Hsp70s was observed, including differential effects by compounds on different Hsp70s despite high conservation (≥ 70 % sequence identity) between the Hsp70s. The five compounds were shown to interact with all three Hsp70s in in vitro binding studies. Differential modulation by compounds was observed between the Hsj1a-stimulated ATPase activities of different Hsp70s, suggestive of not only a high degree of specificity of compounds to chaperone systems, but also distinct interactions between different Hsp70s and Hjs1a. The effects of compounds on the survival of P. falciparum parasites as well as mammalian cells was assessed. Bromo-β-lapachona was found to have broad effects across all systems, modulating the chaperone activities of all three Hsp70s, and showing significant toxicity toward both P. falciparum parasites and mammalian cells in culture. Malonganenone A was found to modulate only the malarial Hsp70s, not human Hsp70, showing significant toxicity toward malarial parasites (IC₅₀ ~ 0.8 μM), and comparatively low toxicity toward mammalian cells, representing therefore a novel starting point for a new class of antimalarials potentially targeting a new antimalarial drug target, Hsp70.
- Full Text:
Money supply endogeneity : an empirical investigation of South African data (2000Q1-2011Q4)
- Authors: Schady, Stuart William
- Date: 2013 , 2013-04-29
- Subjects: Monetary policy -- South Africa , Inflation targeting -- South Africa , Gross domestic product -- South Africa , Bank loans -- South Africa , Money supply -- South Africa , Endogenous growth (Economics) , Domestic credit extension
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:928 , http://hdl.handle.net/10962/d1001454 , Monetary policy -- South Africa , Inflation targeting -- South Africa , Gross domestic product -- South Africa , Bank loans -- South Africa , Money supply -- South Africa , Endogenous growth (Economics)
- Description: This study is about whether the money supply in South Africa under a monetary policy regime of inflation‐targeting is exogenously or endogenously determined. The proposition of an exogenous money supply has been offered by monetarists, where the Central Bank determines the quantity of money supplied to the economy and this has a causal influence on income and credit extension. The endogenous money theory is a post‐Keynesian proposition whereby the money creation is determined by banks adjusting their responses to demands for credit‐money from economic agents. The data analysis is from 2000Q1 to 2010Q4 and entails the use of the variables monetary base (MB), domestic credit extension (DCE), M3, and gross national product (GDP). All variables are logged. The empirical tests conducted start with the Augmented Dickey‐Fuller unit root test to determine the variables order of integration. Johansen cointegration tests are done followed by Vector Error‐Correction Models (VECMs) and Granger causality tests to determine whether there is unidirectional or bidirectional causality between variables over the long and short‐run. Based on the results of the testing it was discovered that over the inflation‐targeting regime money supply in South Africa was endogenously determined. Furthermore, the data best supports the Accommodationist analysis of endogenous money as opposed to that of Structuralism and Liquidity Preference , Adobe Acrobat 9.53 Paper Capture Plug-in
- Full Text:
- Authors: Schady, Stuart William
- Date: 2013 , 2013-04-29
- Subjects: Monetary policy -- South Africa , Inflation targeting -- South Africa , Gross domestic product -- South Africa , Bank loans -- South Africa , Money supply -- South Africa , Endogenous growth (Economics) , Domestic credit extension
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:928 , http://hdl.handle.net/10962/d1001454 , Monetary policy -- South Africa , Inflation targeting -- South Africa , Gross domestic product -- South Africa , Bank loans -- South Africa , Money supply -- South Africa , Endogenous growth (Economics)
- Description: This study is about whether the money supply in South Africa under a monetary policy regime of inflation‐targeting is exogenously or endogenously determined. The proposition of an exogenous money supply has been offered by monetarists, where the Central Bank determines the quantity of money supplied to the economy and this has a causal influence on income and credit extension. The endogenous money theory is a post‐Keynesian proposition whereby the money creation is determined by banks adjusting their responses to demands for credit‐money from economic agents. The data analysis is from 2000Q1 to 2010Q4 and entails the use of the variables monetary base (MB), domestic credit extension (DCE), M3, and gross national product (GDP). All variables are logged. The empirical tests conducted start with the Augmented Dickey‐Fuller unit root test to determine the variables order of integration. Johansen cointegration tests are done followed by Vector Error‐Correction Models (VECMs) and Granger causality tests to determine whether there is unidirectional or bidirectional causality between variables over the long and short‐run. Based on the results of the testing it was discovered that over the inflation‐targeting regime money supply in South Africa was endogenously determined. Furthermore, the data best supports the Accommodationist analysis of endogenous money as opposed to that of Structuralism and Liquidity Preference , Adobe Acrobat 9.53 Paper Capture Plug-in
- Full Text:
Morphology, patterns and processes in the Oyster Bay headland bypass dunefield, South Africa
- Authors: McConnachie, Lauren Bernyse
- Date: 2013
- Subjects: Sand dune conservation -- South Africa -- Eastern Cape Sand dune ecology -- South Africa -- Eastern Cape Coastal ecology -- South Africa -- Eastern Cape Sedimentation and deposition -- South Africa -- Eastern Cape Beach erosion -- South Africa -- Eastern Cape Coastal zone management -- South Africa -- Eastern Cape Shore protection -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4804 , http://hdl.handle.net/10962/d1001904
- Description: Studies of the dunefield systems crossing the Cape St. Francis headland in the Eastern Cape have focused on the role that wind plays in sediment transfer in coastal dunefield systems, with limited consideration of the role of water. The aim of this study was to improve understanding of the morphology, processes and patterns within the Oyster Bay HBD system, focussing particularly on surface water and groundwater interactions and the role of surface water in sediment transfer across the dunefield system. An extensive field survey was conducted, to collect related data, complimented by spatial and temporal analysis of the study area using GIS. The key findings from this research were the apparent differences between the western and eastern regions of the dunefield with regard to specific drivers and the respective processes and responses. Wind is the major driver of change up to and across the crest of the dunefield. In the eastern region water (ground water, surface water and the Sand River System) is the primary agent of sediment flux through processes of aggregation and slumping as well as episodic events including debris flows. This study has highlighted a need for further quantitative studies that investigate the movement of sediment through dunefield systems such as this (where water is at or near the land surface). The paradigm that sediment flux is entirely due to wind is almost certainly simplistic, and deeper understanding of these systems is needed , Maiden name: Elkington, Lauren
- Full Text:
- Authors: McConnachie, Lauren Bernyse
- Date: 2013
- Subjects: Sand dune conservation -- South Africa -- Eastern Cape Sand dune ecology -- South Africa -- Eastern Cape Coastal ecology -- South Africa -- Eastern Cape Sedimentation and deposition -- South Africa -- Eastern Cape Beach erosion -- South Africa -- Eastern Cape Coastal zone management -- South Africa -- Eastern Cape Shore protection -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4804 , http://hdl.handle.net/10962/d1001904
- Description: Studies of the dunefield systems crossing the Cape St. Francis headland in the Eastern Cape have focused on the role that wind plays in sediment transfer in coastal dunefield systems, with limited consideration of the role of water. The aim of this study was to improve understanding of the morphology, processes and patterns within the Oyster Bay HBD system, focussing particularly on surface water and groundwater interactions and the role of surface water in sediment transfer across the dunefield system. An extensive field survey was conducted, to collect related data, complimented by spatial and temporal analysis of the study area using GIS. The key findings from this research were the apparent differences between the western and eastern regions of the dunefield with regard to specific drivers and the respective processes and responses. Wind is the major driver of change up to and across the crest of the dunefield. In the eastern region water (ground water, surface water and the Sand River System) is the primary agent of sediment flux through processes of aggregation and slumping as well as episodic events including debris flows. This study has highlighted a need for further quantitative studies that investigate the movement of sediment through dunefield systems such as this (where water is at or near the land surface). The paradigm that sediment flux is entirely due to wind is almost certainly simplistic, and deeper understanding of these systems is needed , Maiden name: Elkington, Lauren
- Full Text:
Morphology, patterns and processes in the Oyster Bay headland bypass dunefield, South Africa
- Authors: Elkington, Lauren
- Date: 2013
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:20984 , http://hdl.handle.net/10962/5879
- Description: Studies of the dunefield systems crossing the Cape St. Francis headland in the Eastern Cape have focused on the role that wind plays in sediment transfer in coastal dunefield systems, with limited consideration of the role of water. The aim of this study was to improve understanding of the morphology, processes and patterns within the Oyster Bay HBD system, focussing particularly on surface water and groundwater interactions and the role of surface water in sediment transfer across the dunefield system. An extensive field survey was conducted, to collect related data, complimented by spatial and temporal analysis of the study area using GIS. The key findings from this research were the apparent differences between the western and eastern regions of the dunefield with regard to specific drivers and the respective processes and responses. Wind is the major driver of change up to and across the crest of the dunefield. In the eastern region water (ground water, surface water and the Sand River System) is the primary agent of sediment flux through processes of aggregation and slumping as well as episodic events including debris flows. This study has highlighted a need for further quantitative studies that investigate the movement of sediment through dunefield systems such as this (where water is at or near the land surface). The paradigm that sediment flux is entirely due to wind is almost certainly simplistic, and deeper understanding of these systems is needed.
- Full Text:
- Authors: Elkington, Lauren
- Date: 2013
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:20984 , http://hdl.handle.net/10962/5879
- Description: Studies of the dunefield systems crossing the Cape St. Francis headland in the Eastern Cape have focused on the role that wind plays in sediment transfer in coastal dunefield systems, with limited consideration of the role of water. The aim of this study was to improve understanding of the morphology, processes and patterns within the Oyster Bay HBD system, focussing particularly on surface water and groundwater interactions and the role of surface water in sediment transfer across the dunefield system. An extensive field survey was conducted, to collect related data, complimented by spatial and temporal analysis of the study area using GIS. The key findings from this research were the apparent differences between the western and eastern regions of the dunefield with regard to specific drivers and the respective processes and responses. Wind is the major driver of change up to and across the crest of the dunefield. In the eastern region water (ground water, surface water and the Sand River System) is the primary agent of sediment flux through processes of aggregation and slumping as well as episodic events including debris flows. This study has highlighted a need for further quantitative studies that investigate the movement of sediment through dunefield systems such as this (where water is at or near the land surface). The paradigm that sediment flux is entirely due to wind is almost certainly simplistic, and deeper understanding of these systems is needed.
- Full Text:
Movement patterns and genetic stock delineation of an endemic South African sparid, the Poenskop, Cymatoceps nasutus (Castelnau, 1861)
- Authors: Murray, Taryn Sara
- Date: 2013
- Subjects: Fish stock assessment -- South Africa , Sparidae -- South Africa , Fishes -- Reproduction -- South Africa , Fishing -- South Africa , Fish populations -- South Africa , Fishes -- Behavior -- South Africa , Marine fishes -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5178 , http://hdl.handle.net/10962/d1001514 , Fish stock assessment -- South Africa , Sparidae -- South Africa , Fishes -- Reproduction -- South Africa , Fishing -- South Africa , Fish populations -- South Africa , Fishes -- Behavior -- South Africa , Marine fishes -- South Africa
- Description: Poenskop Cymatoceps nasutus (Pisces: Sparidae), an endemic South African sparid, is an important angling species being predominantly targeted by the recreational shore and skiboat sector. This species is slow-growing, long-lived, late-maturing and sex-changing, making poenskop acutely sensitive to over-exploitation. Despite interventions, such as the imposition of size and bag limits (currently 50 cm TL and one per licensed fisher per day) by authorities, catch-per-unit-effort trends reflect a severe and consistent stock decline over the last two decades. Poenskop has been identified as a priority species for research and conservation. Although the biology and population dynamics of this species have been well-documented, little is known about the movement behaviour of poenskop. Furthermore, there is a complete lack of information on its genetic stock structure. This thesis aimed to address the current knowledge gaps concerning movement behaviour and genetic stock structure of poenskop, making use of a range of methods and drawing on available information, including available fishery records as well as published and unpublished survey and research data, and data from long-term monitoring programmes. Analysis of available catch data (published and unpublished) revealed a decline in the number of poenskop caught as well as size of fish taken over the last two decades, ultimately reflecting the collapse of the stock (estimated to be at 20% of their pristine level). Improved catch-per-unit-effort data from the Tsitsikamma National Park Marine Protected Area (MPA), and larger poenskop being caught in the no-take areas than adjacent exploited areas of the Pondoland MPA confirmed that MPAs can be effective for the protection and management of poenskop. The current MPA network in South Africa is already wellestablished, and encompasses considerable reef areas, being preferable for poenskop habitation. Conventional dart tagging and recapture information from three ongoing, long-term fishtagging projects, conducted throughout the poenskop’s distribution, indicated high levels of residency at all life-history stages. Coastal region, seasonality and time at recapture did not appear to have a significant effect on the level of movement or distance moved. However, on examining the relationship among coastal movements and fish size and ages, larger and older fish (adults) moved greater distances, with juveniles and sub-adults showing high degrees of residency. An estimation of home-range size indicated smaller poenskop to hold smaller home-ranges, while larger poenskop hold larger home-ranges. Large easterly displacements of a number of adult poenskop is in accordance with previous findings that this species may undertake a unidirectional migration up the coastline of South Africa where they possibly settle in Transkei waters for the remainder of their lives. This high level of residency makes poenskop vulnerable to localised depletion, although they can be effectively protected by suitable MPAs. Despite considerable tagging effort along the South African coastline (2 704 poenskop tagged with 189 recaptures, between 1984 and 2010), there remains limited information on the connectivity of different regions along the South African coastline. This was addressed using mitochondrial DNA sequencing. The mitochondrial DNA control region was used due to its high substitution rate, haploid nature, maternal inheritance and absence of recombination. The mtDNA sequencing showed no evidence of major geographic barriers to gene flow in this species. Samples collected throughout the core distribution of poenskop showed high genetic diversity (h = 0.88, π = 0.01), low genetic differentiation among regions, no spatial structure (ɸST = 0.012, p = 0.208) and no evidence of isolation by distance. The collapsed stock status of poenskop as well as the fact that it is being actively targeted by recreational and commercial fishers suggests that this species requires improved management, with consideration given to its life-history style, residency and poor conservation status. Management recommendations for poenskop, combined with increasing South Africa’s existing MPA network, include the possibility of setting up a closed season (during known spawning periods) as well as the decommercialisation of this species. The techniques used and developed in this study can also be adopted for other overexploited linefish species.
- Full Text:
- Authors: Murray, Taryn Sara
- Date: 2013
- Subjects: Fish stock assessment -- South Africa , Sparidae -- South Africa , Fishes -- Reproduction -- South Africa , Fishing -- South Africa , Fish populations -- South Africa , Fishes -- Behavior -- South Africa , Marine fishes -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5178 , http://hdl.handle.net/10962/d1001514 , Fish stock assessment -- South Africa , Sparidae -- South Africa , Fishes -- Reproduction -- South Africa , Fishing -- South Africa , Fish populations -- South Africa , Fishes -- Behavior -- South Africa , Marine fishes -- South Africa
- Description: Poenskop Cymatoceps nasutus (Pisces: Sparidae), an endemic South African sparid, is an important angling species being predominantly targeted by the recreational shore and skiboat sector. This species is slow-growing, long-lived, late-maturing and sex-changing, making poenskop acutely sensitive to over-exploitation. Despite interventions, such as the imposition of size and bag limits (currently 50 cm TL and one per licensed fisher per day) by authorities, catch-per-unit-effort trends reflect a severe and consistent stock decline over the last two decades. Poenskop has been identified as a priority species for research and conservation. Although the biology and population dynamics of this species have been well-documented, little is known about the movement behaviour of poenskop. Furthermore, there is a complete lack of information on its genetic stock structure. This thesis aimed to address the current knowledge gaps concerning movement behaviour and genetic stock structure of poenskop, making use of a range of methods and drawing on available information, including available fishery records as well as published and unpublished survey and research data, and data from long-term monitoring programmes. Analysis of available catch data (published and unpublished) revealed a decline in the number of poenskop caught as well as size of fish taken over the last two decades, ultimately reflecting the collapse of the stock (estimated to be at 20% of their pristine level). Improved catch-per-unit-effort data from the Tsitsikamma National Park Marine Protected Area (MPA), and larger poenskop being caught in the no-take areas than adjacent exploited areas of the Pondoland MPA confirmed that MPAs can be effective for the protection and management of poenskop. The current MPA network in South Africa is already wellestablished, and encompasses considerable reef areas, being preferable for poenskop habitation. Conventional dart tagging and recapture information from three ongoing, long-term fishtagging projects, conducted throughout the poenskop’s distribution, indicated high levels of residency at all life-history stages. Coastal region, seasonality and time at recapture did not appear to have a significant effect on the level of movement or distance moved. However, on examining the relationship among coastal movements and fish size and ages, larger and older fish (adults) moved greater distances, with juveniles and sub-adults showing high degrees of residency. An estimation of home-range size indicated smaller poenskop to hold smaller home-ranges, while larger poenskop hold larger home-ranges. Large easterly displacements of a number of adult poenskop is in accordance with previous findings that this species may undertake a unidirectional migration up the coastline of South Africa where they possibly settle in Transkei waters for the remainder of their lives. This high level of residency makes poenskop vulnerable to localised depletion, although they can be effectively protected by suitable MPAs. Despite considerable tagging effort along the South African coastline (2 704 poenskop tagged with 189 recaptures, between 1984 and 2010), there remains limited information on the connectivity of different regions along the South African coastline. This was addressed using mitochondrial DNA sequencing. The mitochondrial DNA control region was used due to its high substitution rate, haploid nature, maternal inheritance and absence of recombination. The mtDNA sequencing showed no evidence of major geographic barriers to gene flow in this species. Samples collected throughout the core distribution of poenskop showed high genetic diversity (h = 0.88, π = 0.01), low genetic differentiation among regions, no spatial structure (ɸST = 0.012, p = 0.208) and no evidence of isolation by distance. The collapsed stock status of poenskop as well as the fact that it is being actively targeted by recreational and commercial fishers suggests that this species requires improved management, with consideration given to its life-history style, residency and poor conservation status. Management recommendations for poenskop, combined with increasing South Africa’s existing MPA network, include the possibility of setting up a closed season (during known spawning periods) as well as the decommercialisation of this species. The techniques used and developed in this study can also be adopted for other overexploited linefish species.
- Full Text:
Nanostructured β-cyclodextrin-hyperbranched polyethyleneimine (β-CD-HPEI) embedded in polysulfone membrane for the removal of humic acid from water
- Malinga, S P, Arotiba, O A, Mapolie, S F, Diallo, M S, Mamba, Bhekie B, Krause, Rui W M
- Authors: Malinga, S P , Arotiba, O A , Mapolie, S F , Diallo, M S , Mamba, Bhekie B , Krause, Rui W M
- Date: 2013
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/125119 , vital:35732 , https://doi.org/10.1080/01496395.2013.809108
- Description: The synthesis of a new β-cyclodextrin-hyperbranched polyethyleneimine (β-CD-HPEI)/polysulfone (PSf) membranes via interfacial polymerization of trimesoyl chloride and β-CD-HPEI is described in this paper. The membranes were characterized by atomic force microscopy (AFM), high resolution scanning electron microscopy (HR-SEM) and contact-angle measurements. Water permeability and rejection data were obtained using a cross-flow filtration system at 0.69 MPa. The membranes were hydrophilic (25° to 63°), showed high humic acid rejection (>amp;80%), and maintained a constant flux throughout the filtration. The modified membranes were rougher than the pristine PSf membranes but they exhibited better antifouling properties due to the hydrophilic surface which acted as a barrier against humic acid deposition. The modification of PSf with β-CD-HPEI resulted in enhanced hydrophilicity and water permeability while still maintaining high humic acid rejection. Supplemental materials are available for this article. Go to the publisher's online edition of Separation Science & Technology to view the supplemental file.
- Full Text:
- Authors: Malinga, S P , Arotiba, O A , Mapolie, S F , Diallo, M S , Mamba, Bhekie B , Krause, Rui W M
- Date: 2013
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/125119 , vital:35732 , https://doi.org/10.1080/01496395.2013.809108
- Description: The synthesis of a new β-cyclodextrin-hyperbranched polyethyleneimine (β-CD-HPEI)/polysulfone (PSf) membranes via interfacial polymerization of trimesoyl chloride and β-CD-HPEI is described in this paper. The membranes were characterized by atomic force microscopy (AFM), high resolution scanning electron microscopy (HR-SEM) and contact-angle measurements. Water permeability and rejection data were obtained using a cross-flow filtration system at 0.69 MPa. The membranes were hydrophilic (25° to 63°), showed high humic acid rejection (>amp;80%), and maintained a constant flux throughout the filtration. The modified membranes were rougher than the pristine PSf membranes but they exhibited better antifouling properties due to the hydrophilic surface which acted as a barrier against humic acid deposition. The modification of PSf with β-CD-HPEI resulted in enhanced hydrophilicity and water permeability while still maintaining high humic acid rejection. Supplemental materials are available for this article. Go to the publisher's online edition of Separation Science & Technology to view the supplemental file.
- Full Text:
New ways of understanding: a governmentality analysis of basic education policy in post-apartheid South Africa
- Authors: Prinsloo, Estelle Helena
- Date: 2013
- Subjects: South Africa -- Department of Basic Education , Basic education -- Government policy -- Research -- South Africa , Post-apartheid era -- Education -- South Africa , Educational change -- Research -- South Africa , South Africa -- Social conditions
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: vital:2751 , http://hdl.handle.net/10962/d1001384
- Description: Social problems that are identified by government policy are articulated in ways that confer the responsibility of their management onto the state. In this way, policy reform serves as a means to justify political rule, as the ‘answers’ to policy failures are located within the realm of state intervention. This role of policy is maintained by the traditional definition of policy as it enables policies to be presented as the outcome of ‘necessary’ actions taken by state institutions to better the wellbeing of citizens. Since 1994, mainstream research on basic education policy in South Africa has employed traditional understandings of policy and its function. In doing so, these inquiries have failed to question the very idea of policy itself. They have also neglected to identify the productive role played by policy in the practice of power. To illuminate the necessary limits of policy reform, an alternative approach to analyse basic education policy is necessary. This thesis premises policy as discourse and advances a governmentality analysis of basic education policy during the first fifteen years of democracy (1994-2009) in South Africa. By drawing on the work of Michel Foucault, the study argues that government – ‘those actions upon the actions of others’ – during this period in South Africa was informed by both a liberal and a neo-liberal mentality of rule. The tensions between these two rationalities contributed to the continuation of apartheid’s socio-economic inequalities in the postapartheid era; an outcome buttressed by the contradictory impulses within basic education policy. By considering policy as a productive translation of governmental reasoning, the boundaries of intervention for future policy reforms are highlighted. These show that the inequalities that were perpetuated during the first fifteen years of democracy justify policy responses similar to those responsible for their production
- Full Text:
- Authors: Prinsloo, Estelle Helena
- Date: 2013
- Subjects: South Africa -- Department of Basic Education , Basic education -- Government policy -- Research -- South Africa , Post-apartheid era -- Education -- South Africa , Educational change -- Research -- South Africa , South Africa -- Social conditions
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: vital:2751 , http://hdl.handle.net/10962/d1001384
- Description: Social problems that are identified by government policy are articulated in ways that confer the responsibility of their management onto the state. In this way, policy reform serves as a means to justify political rule, as the ‘answers’ to policy failures are located within the realm of state intervention. This role of policy is maintained by the traditional definition of policy as it enables policies to be presented as the outcome of ‘necessary’ actions taken by state institutions to better the wellbeing of citizens. Since 1994, mainstream research on basic education policy in South Africa has employed traditional understandings of policy and its function. In doing so, these inquiries have failed to question the very idea of policy itself. They have also neglected to identify the productive role played by policy in the practice of power. To illuminate the necessary limits of policy reform, an alternative approach to analyse basic education policy is necessary. This thesis premises policy as discourse and advances a governmentality analysis of basic education policy during the first fifteen years of democracy (1994-2009) in South Africa. By drawing on the work of Michel Foucault, the study argues that government – ‘those actions upon the actions of others’ – during this period in South Africa was informed by both a liberal and a neo-liberal mentality of rule. The tensions between these two rationalities contributed to the continuation of apartheid’s socio-economic inequalities in the postapartheid era; an outcome buttressed by the contradictory impulses within basic education policy. By considering policy as a productive translation of governmental reasoning, the boundaries of intervention for future policy reforms are highlighted. These show that the inequalities that were perpetuated during the first fifteen years of democracy justify policy responses similar to those responsible for their production
- Full Text:
Novel applications of Morita-Baylis-Hillman methodology in organic synthesis
- Authors: Mciteka, Lulama Patrick
- Date: 2013 , 2013-04-22
- Subjects: Organic compounds -- Synthesis -- Research Asymmetric synthesis Asymmetry (Chemistry) Chemical reactions -- Research Camphor -- Research AZT (Drug) -- Research Chemical inhibitors -- Research Chemistry -- Methodology
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4439 , http://hdl.handle.net/10962/d1007598
- Description: The overall approach in the present investigation has been to explore applications of the Morita-Baylis-Hillman (MBH) reaction in asymmetric synthesis and in the continuation of systems with medicinal potential. To this end, a series of varied camphor-derived acrylate esters was prepared to serve as chiral substrates in asymmetric Morita-Baylis- Hillman reactions. Reduction of N-substituted camphor-10-sulfonamides afforded the 3- exo-hydroxy derivatives as the major products. Acylation of the corresponding sodium alkoxides gave the desired 3-exo-acrylate esters, isolation of which was complicated by concomitant formation of hydrochlorinated and diastereomeric competition products. Bulky camphorsulfonamides containing alkyl, dialkyl, aromatic and adamantyl groups were selected as N-substituents with the view of achieving stereoselective outcome in subsequent MBH reactions. The synthesis of novel camphor-derived Morita-Baylis-Hillman adducts using various pyridine-carboxaldehydes proceeded with exceptionally high yields with diastereoselectivities ranging from 7-33 % d.e. Both 1D and 2D NMR and HRMS techniques were employed to confirm the structures and an extensive study of the electropositive fragmentation patterns of a number of camphor-derived chiral acrylate esters was conducted. Attention has also been given to the application of MBH methodology in the construction of heterocyclic ‘cinnamate-like’ AZT conjugates which were designed to serve as dualaction HIV-1 integrase-reverse transcriptase (IN-RT) inhibitors. A number of pyridine carboxaldehyde-derived MBH adducts were synthesized using methyl, ethyl and t-butyl acrylates in the presence of 3-hydroxyquinuclidine (3-HQ) as catalyst. The yields for these reactions were excellent. The resulting MBH adducts were acetylated and subjected to aza-Michael addition using propargylamine. The resulting alkylamino compounds were then used in ‘Click reactions’ to form the targeted AZT-conjugates in moderate to excellent yield. In silico docking of computer modelled AZT-conjugates into the HIV-1 integrase and reverse transcriptase enzyme-active sites and potential hydrogen-bonding interaction with active-site amino acid residues were identified. The electrospray MS fragmentations of the AZT and the novel AZT-conjugates were also investigated and common fragmentation pathways were identified.
- Full Text:
- Authors: Mciteka, Lulama Patrick
- Date: 2013 , 2013-04-22
- Subjects: Organic compounds -- Synthesis -- Research Asymmetric synthesis Asymmetry (Chemistry) Chemical reactions -- Research Camphor -- Research AZT (Drug) -- Research Chemical inhibitors -- Research Chemistry -- Methodology
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4439 , http://hdl.handle.net/10962/d1007598
- Description: The overall approach in the present investigation has been to explore applications of the Morita-Baylis-Hillman (MBH) reaction in asymmetric synthesis and in the continuation of systems with medicinal potential. To this end, a series of varied camphor-derived acrylate esters was prepared to serve as chiral substrates in asymmetric Morita-Baylis- Hillman reactions. Reduction of N-substituted camphor-10-sulfonamides afforded the 3- exo-hydroxy derivatives as the major products. Acylation of the corresponding sodium alkoxides gave the desired 3-exo-acrylate esters, isolation of which was complicated by concomitant formation of hydrochlorinated and diastereomeric competition products. Bulky camphorsulfonamides containing alkyl, dialkyl, aromatic and adamantyl groups were selected as N-substituents with the view of achieving stereoselective outcome in subsequent MBH reactions. The synthesis of novel camphor-derived Morita-Baylis-Hillman adducts using various pyridine-carboxaldehydes proceeded with exceptionally high yields with diastereoselectivities ranging from 7-33 % d.e. Both 1D and 2D NMR and HRMS techniques were employed to confirm the structures and an extensive study of the electropositive fragmentation patterns of a number of camphor-derived chiral acrylate esters was conducted. Attention has also been given to the application of MBH methodology in the construction of heterocyclic ‘cinnamate-like’ AZT conjugates which were designed to serve as dualaction HIV-1 integrase-reverse transcriptase (IN-RT) inhibitors. A number of pyridine carboxaldehyde-derived MBH adducts were synthesized using methyl, ethyl and t-butyl acrylates in the presence of 3-hydroxyquinuclidine (3-HQ) as catalyst. The yields for these reactions were excellent. The resulting MBH adducts were acetylated and subjected to aza-Michael addition using propargylamine. The resulting alkylamino compounds were then used in ‘Click reactions’ to form the targeted AZT-conjugates in moderate to excellent yield. In silico docking of computer modelled AZT-conjugates into the HIV-1 integrase and reverse transcriptase enzyme-active sites and potential hydrogen-bonding interaction with active-site amino acid residues were identified. The electrospray MS fragmentations of the AZT and the novel AZT-conjugates were also investigated and common fragmentation pathways were identified.
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