Love Interrupted (Short story anthology)
- Authors: Malatji, Reneilwe
- Date: 2012
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:21016 , http://hdl.handle.net/10962/6004
- Description: This collection of stories focuses on struggles between black South African men and women. Several of the stories explore how the rise of the affluent and powerful black woman is redefining relationships. Other stories in the collection describe women who do not know how to free themselves from their subservient role, or do not want to. Issues of interracial relations between blacks and whites in contemporary South Africa also feature in most of the stories.
- Full Text:
- Date Issued: 2012
- Authors: Malatji, Reneilwe
- Date: 2012
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:21016 , http://hdl.handle.net/10962/6004
- Description: This collection of stories focuses on struggles between black South African men and women. Several of the stories explore how the rise of the affluent and powerful black woman is redefining relationships. Other stories in the collection describe women who do not know how to free themselves from their subservient role, or do not want to. Issues of interracial relations between blacks and whites in contemporary South Africa also feature in most of the stories.
- Full Text:
- Date Issued: 2012
Musculoskeletal and perceptual responses of batsmen comparing high- and moderate-volume sprints between the wickets
- Authors: Sheppard, Bronwyn Jane
- Date: 2012
- Subjects: Cricket -- Batting -- Physiological aspects , Cricket injuries , Musculoskeletal system -- Wounds and injuries
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5171 , http://hdl.handle.net/10962/d1016366
- Description: Background: Literature has associated repeated eccentric muscle actions with increased muscle damage of the muscles involved. Eccentric actions are typical in sports which are ‘stop-start’ in nature requiring rapid acceleration and deceleration, typical of a batting activity in cricket. Ultra-structural damage of the skeletal muscle as a consequence of repeated decelerating activities is associated with performance decrements, particularly muscle strength and sprinting speeds. This suggests that eccentric strength decrements may provide an indication for the development of muscle strain injuries during these activities. Despite these findings, limited research has identified the specific musculoskeletal demands placed on cricket batsmen, particularly with reference to various match intensities. Objective: The present study, therefore, sought to determine the specific musculoskeletal, physiological and perceptual demands placed on specialised batsmen during two work bouts of different intensities; one representing a highintensity work bout and the other a moderate-intensity work bout. The dependent variables of interest were muscle activation, isokinetic strength changes, heart rate, ‘central’ and ‘local’ ratings of perceived exertion (RPE), body discomfort and performance. Methods: The two experimental conditions, representative of a high- (HVR) and moderate-volume running (MVR) batting protocol, required players to perform a simulated batting work bout of either twelve or six runs an over, within a laboratory setting. Selected physiological, perceptual and performance measures were collected at specific time intervals throughout the work bout while the biophysical measures were collected prior to, and following both protocols. Results: Of the variables measured, heart rate, ‘central’ and ‘local’ RPE values were observed to increase significantly (p<0.05) over time. This increase was greater as a consequence of the HVR in comparison to the MVR. No change in sprint times was documented during the MVR, in contrast, significant (p<0.05) increases over time were observed during the HVR, further highlighting the elevated demands associated with this condition. In addition, an ‘end spurt’ was observed particularly following the HVR condition, suggesting athletes were conserving themselves through the adoption of a pacing strategy. Reductions in biceps femoris and semitendinosus muscle activation levels were observed following the HVR. This was further supported by the significantly greater levels of semitendinosus activation following the MVR when compared to the HVR. Peak concentric and eccentric knee extensor (EXT) (-17.17% and -16.07% respectively) and eccentric flexor (FLEX) (- 17.49%) values decreased significantly (p<0.05) following the HVR at 60°.s-1. In addition, concentric and eccentric total work produced by the flexors and eccentric extensors resulted in significantly (p<0.05) lower values due to the HVR. Conclusion: The intermittent high-volume batting work bout elicited elevated mean heart rates, perceived ratings of cardiovascular and muscular effort and sprint times. Furthermore, hamstring activation levels and muscle strength, particularly concentric strength of the dominant lower limb were negatively affected by the HVR condition. These results suggest elevated demands were placed on the hamstring musculature as a consequence of the HVR condition, indicating a greater degree of musculoskeletal strain and increased injury risk associated with running between the wickets at this intensity, representative of an aggressive batting scenario.
- Full Text:
- Date Issued: 2012
- Authors: Sheppard, Bronwyn Jane
- Date: 2012
- Subjects: Cricket -- Batting -- Physiological aspects , Cricket injuries , Musculoskeletal system -- Wounds and injuries
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5171 , http://hdl.handle.net/10962/d1016366
- Description: Background: Literature has associated repeated eccentric muscle actions with increased muscle damage of the muscles involved. Eccentric actions are typical in sports which are ‘stop-start’ in nature requiring rapid acceleration and deceleration, typical of a batting activity in cricket. Ultra-structural damage of the skeletal muscle as a consequence of repeated decelerating activities is associated with performance decrements, particularly muscle strength and sprinting speeds. This suggests that eccentric strength decrements may provide an indication for the development of muscle strain injuries during these activities. Despite these findings, limited research has identified the specific musculoskeletal demands placed on cricket batsmen, particularly with reference to various match intensities. Objective: The present study, therefore, sought to determine the specific musculoskeletal, physiological and perceptual demands placed on specialised batsmen during two work bouts of different intensities; one representing a highintensity work bout and the other a moderate-intensity work bout. The dependent variables of interest were muscle activation, isokinetic strength changes, heart rate, ‘central’ and ‘local’ ratings of perceived exertion (RPE), body discomfort and performance. Methods: The two experimental conditions, representative of a high- (HVR) and moderate-volume running (MVR) batting protocol, required players to perform a simulated batting work bout of either twelve or six runs an over, within a laboratory setting. Selected physiological, perceptual and performance measures were collected at specific time intervals throughout the work bout while the biophysical measures were collected prior to, and following both protocols. Results: Of the variables measured, heart rate, ‘central’ and ‘local’ RPE values were observed to increase significantly (p<0.05) over time. This increase was greater as a consequence of the HVR in comparison to the MVR. No change in sprint times was documented during the MVR, in contrast, significant (p<0.05) increases over time were observed during the HVR, further highlighting the elevated demands associated with this condition. In addition, an ‘end spurt’ was observed particularly following the HVR condition, suggesting athletes were conserving themselves through the adoption of a pacing strategy. Reductions in biceps femoris and semitendinosus muscle activation levels were observed following the HVR. This was further supported by the significantly greater levels of semitendinosus activation following the MVR when compared to the HVR. Peak concentric and eccentric knee extensor (EXT) (-17.17% and -16.07% respectively) and eccentric flexor (FLEX) (- 17.49%) values decreased significantly (p<0.05) following the HVR at 60°.s-1. In addition, concentric and eccentric total work produced by the flexors and eccentric extensors resulted in significantly (p<0.05) lower values due to the HVR. Conclusion: The intermittent high-volume batting work bout elicited elevated mean heart rates, perceived ratings of cardiovascular and muscular effort and sprint times. Furthermore, hamstring activation levels and muscle strength, particularly concentric strength of the dominant lower limb were negatively affected by the HVR condition. These results suggest elevated demands were placed on the hamstring musculature as a consequence of the HVR condition, indicating a greater degree of musculoskeletal strain and increased injury risk associated with running between the wickets at this intensity, representative of an aggressive batting scenario.
- Full Text:
- Date Issued: 2012
Macroeconomic determinants of stock market behaviour in South Africa
- Authors: Junkin, Kyle
- Date: 2012
- Subjects: Stocks -- Prices -- South Africa Macroeconomics Risk management -- South Africa Stock exchanges -- South Africa Interest rates -- South Africa
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:1016 , http://hdl.handle.net/10962/d1002751
- Description: This study investigates whether stock prices in South Africa are influenced by macroeconomic variables, and furthermore, the effects of financial crises on stock prices. The relationship between stock prices and the macroeconomy is a particularly important issue for investors, since a thorough understanding of such a relationship is likely to yield profitable or risk mitigating opportunities. Using monthly data for the period 1995 to 2010 the study focused at a macro level using the FTSE/JSE All Share Index, and at a micro level using sector indices. These included the construction and materials, financial, food producers’, general retailers, industrial, mining and pharmaceuticals indices. The Johansen and Juselius (1990) multivariate cointegration approach was employed, along with impulse response and variance decomposition tests to address the issue. The results showed that macroeconomic variables do have a significant influence on stock prices in South Africa. Also, the influences of these variables were found to have an inconsistent effect across the sectors under investigation. For example, inflation was found to negatively influence the All Share Index, but impacted the industrial index positively. These inconsistent influences on the various sectors were seen to have important diversification implications for investors. The impact of past financial crises proved to be significant on certain indices, however, indices such as that of the pharmaceuticals sector was found to be largely unaffected by such crises. The findings of the study were discussed through an investor’s perspective, and recommendations on investment decisions were given. The limitations of the study were such that certain results may have been influenced by a mis-specification of variables, particularly the Treasury bill rate.
- Full Text:
- Date Issued: 2012
- Authors: Junkin, Kyle
- Date: 2012
- Subjects: Stocks -- Prices -- South Africa Macroeconomics Risk management -- South Africa Stock exchanges -- South Africa Interest rates -- South Africa
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:1016 , http://hdl.handle.net/10962/d1002751
- Description: This study investigates whether stock prices in South Africa are influenced by macroeconomic variables, and furthermore, the effects of financial crises on stock prices. The relationship between stock prices and the macroeconomy is a particularly important issue for investors, since a thorough understanding of such a relationship is likely to yield profitable or risk mitigating opportunities. Using monthly data for the period 1995 to 2010 the study focused at a macro level using the FTSE/JSE All Share Index, and at a micro level using sector indices. These included the construction and materials, financial, food producers’, general retailers, industrial, mining and pharmaceuticals indices. The Johansen and Juselius (1990) multivariate cointegration approach was employed, along with impulse response and variance decomposition tests to address the issue. The results showed that macroeconomic variables do have a significant influence on stock prices in South Africa. Also, the influences of these variables were found to have an inconsistent effect across the sectors under investigation. For example, inflation was found to negatively influence the All Share Index, but impacted the industrial index positively. These inconsistent influences on the various sectors were seen to have important diversification implications for investors. The impact of past financial crises proved to be significant on certain indices, however, indices such as that of the pharmaceuticals sector was found to be largely unaffected by such crises. The findings of the study were discussed through an investor’s perspective, and recommendations on investment decisions were given. The limitations of the study were such that certain results may have been influenced by a mis-specification of variables, particularly the Treasury bill rate.
- Full Text:
- Date Issued: 2012
The praxis of responsible investment in South Africa: a holistic case study of Evolution One Fund
- Zaulochnaya Ya-Brouwer, Irina
- Authors: Zaulochnaya Ya-Brouwer, Irina
- Date: 2012
- Subjects: Social responsibility of business -- South Africa Investments -- Moral and ethical aspects -- South Africa Institutional investments -- Moral and ethical aspects -- South Africa Private equity funds -- South Africa
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:778 , http://hdl.handle.net/10962/d1003899
- Description: At the beginning of the 21st century the public interest in environmental and social sustainability, and corporate governance grew exponentially fuelled by recurring ecological and financial crises. The market demand for cleaner production and corporate transparency created opportunities for sustainability entrepreneurs in a variety of industries, including financial markets and investment management. An increasing number of financial institutions across the world now offer ethical or socially responsible products to meet the environmental, social and governance (ESG) aspirations of their clients. In the US, according to the Social Investment Forum (SIF), responsible investment (RI) assets reached US$ 2,29 trillion in 2007 (Mitchell, 2008). The European Sustainable Investment Forum (EuroSIF) estimated that total European SRI assets reached EUR 5 trillion in 2009 (Wheelan, 2010). In June 2011 the International Finance Corporation (IFC) reported that at the end of 2010 professional sustainable investment under management in South Africa approximately equalled US$ 122,6 billion (IFC, 2011:44). The statistics describing the rapid growth in the ESG-type investments are, however, complicated by the variety of names and definitions used to describe this emerging type of investment and a general market uncertainty about what constitutes the practice of RI. The purpose of this case study is to better understand responsible investment principles and practice as seen through the eyes of a South African private equity fund, which specializes in clean technology.
- Full Text:
- Date Issued: 2012
- Authors: Zaulochnaya Ya-Brouwer, Irina
- Date: 2012
- Subjects: Social responsibility of business -- South Africa Investments -- Moral and ethical aspects -- South Africa Institutional investments -- Moral and ethical aspects -- South Africa Private equity funds -- South Africa
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:778 , http://hdl.handle.net/10962/d1003899
- Description: At the beginning of the 21st century the public interest in environmental and social sustainability, and corporate governance grew exponentially fuelled by recurring ecological and financial crises. The market demand for cleaner production and corporate transparency created opportunities for sustainability entrepreneurs in a variety of industries, including financial markets and investment management. An increasing number of financial institutions across the world now offer ethical or socially responsible products to meet the environmental, social and governance (ESG) aspirations of their clients. In the US, according to the Social Investment Forum (SIF), responsible investment (RI) assets reached US$ 2,29 trillion in 2007 (Mitchell, 2008). The European Sustainable Investment Forum (EuroSIF) estimated that total European SRI assets reached EUR 5 trillion in 2009 (Wheelan, 2010). In June 2011 the International Finance Corporation (IFC) reported that at the end of 2010 professional sustainable investment under management in South Africa approximately equalled US$ 122,6 billion (IFC, 2011:44). The statistics describing the rapid growth in the ESG-type investments are, however, complicated by the variety of names and definitions used to describe this emerging type of investment and a general market uncertainty about what constitutes the practice of RI. The purpose of this case study is to better understand responsible investment principles and practice as seen through the eyes of a South African private equity fund, which specializes in clean technology.
- Full Text:
- Date Issued: 2012
The synthesis and breast cancer inhibitory activity of cinnamic acid analogues based on the halogenated monoterpene pharmacophore
- Authors: Chiwakata, Maynard Tendai
- Date: 2012
- Subjects: Halocarbons , Cancer -- Treatment , Breast -- Cancer -- Treatment
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3866 , http://hdl.handle.net/10962/d1016129
- Description: Breast cancer is one of the leading causes of death, with mortality rate estimates of 465 000 deaths per annum. It is estimated that 1.3 million women are diagnosed with the disease each year especially in the developing countries. Current chemotherapy relies on the use of high doses of non-specific toxic agents that possess adverse side effects and compromise patient’s compliance and adherence to treatment. Paclitaxel, one of the common drugs used in breast cancer chemotherapy results in sensory and motor neuropathy, whilst hormonal therapy e.g. Herceptin causes severe cardiovascular, gastrointestinal and cutaneous side effects. There has been a demand in developing newer cancer agents that demonstrate selective cytoxicity with minimal effect on normal body tissue. Numerous studies have shown that marine organisms produce a wide range of halogenated compounds that possess cytotoxic properties, and hence can be a source of new drug hits or leads for cancer therapy. Halomon, a polyhalogenated monoterpene from Portieria hornemannii, displayed interesting activity against brain, renal and lung cancer tumours with selective/differential cytotoxicity. This inspired us to focus our project on halogenated monoterpenes isolated from the same Rhodophyta class as P. hornemannii but with particular attention to Plocamium species. Several metabolites have been isolated from P. cornutum, P. corallorhiza and P. suhrii that possess interesting cytotoxicities against a breast cancer cell line (MCF7) and an oesophageal cancer line (WHCO1). The aim of the project was therefore centred at isolating target compounds for preliminary structure-activity studies against a breast cancer cell line, and use this information to synthesize a series of analogues that are more stable than the natural products and yet as active using a fragment-based type approach to map out pharmacophoric elements. Five metabolites were isolated from P. cornutum and five from P. corallorhiza. Cell-based assays were conducted using an MTT assay kit against MCF7 and MDA-MB-231 breast cancer cell lines and (1E,3E,5S,6R)-1,5,6-trichloro-2-(dichloromethyl)-6-methylocta-1,3,7-triene, isolated from P. cornutum was the most active with IC50 values of 3.0 μM and 6.15 μM respectively. Introduction of a terminal aromatic ring to enhance stability, together with varying substituents (H, CH3, CF3, Br, CN, CHO, CHCl2) on position 7 of the molecule, gave rise to a series of cinnamate ester derivatives inspired by (1E,3E,5S,6R)-1,5,6-trichloro-2-(dichloromethyl)-6-methylocta-1,3,7-triene. The analogues were synthesized from their benzaldehyde precursors via Aldol condensation, esterification and Wittig reactions. Their carboxylic acid counterparts were synthesized by hydrolysis of the parent esters in an attempt to promote water solubilities of the analogues. Biological activity assays were then conducted with the cinnamate analogues against the MDA-MB-231 breast cancer cell line using an MTT assay kit. Ester derivatives with -CHO and -CHCl2 functionalities had IC50 values of 43.45 μM and 100.01 μM respectively whilst the other ester derivatives were inactive. It was concluded that either an aldehyde (-CHO) or gem-dichlorides (-CHCl2) is specifically required for cytotoxic activity to be observed. None of the carboxylic acids were active which could have been due to failure of the compounds to enter the breast cancer cells and reach the target site because of their polar nature. Compounds with -CHO and -CHCl2 functionalities were therefore selected for future SARs studies.
- Full Text:
- Date Issued: 2012
- Authors: Chiwakata, Maynard Tendai
- Date: 2012
- Subjects: Halocarbons , Cancer -- Treatment , Breast -- Cancer -- Treatment
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3866 , http://hdl.handle.net/10962/d1016129
- Description: Breast cancer is one of the leading causes of death, with mortality rate estimates of 465 000 deaths per annum. It is estimated that 1.3 million women are diagnosed with the disease each year especially in the developing countries. Current chemotherapy relies on the use of high doses of non-specific toxic agents that possess adverse side effects and compromise patient’s compliance and adherence to treatment. Paclitaxel, one of the common drugs used in breast cancer chemotherapy results in sensory and motor neuropathy, whilst hormonal therapy e.g. Herceptin causes severe cardiovascular, gastrointestinal and cutaneous side effects. There has been a demand in developing newer cancer agents that demonstrate selective cytoxicity with minimal effect on normal body tissue. Numerous studies have shown that marine organisms produce a wide range of halogenated compounds that possess cytotoxic properties, and hence can be a source of new drug hits or leads for cancer therapy. Halomon, a polyhalogenated monoterpene from Portieria hornemannii, displayed interesting activity against brain, renal and lung cancer tumours with selective/differential cytotoxicity. This inspired us to focus our project on halogenated monoterpenes isolated from the same Rhodophyta class as P. hornemannii but with particular attention to Plocamium species. Several metabolites have been isolated from P. cornutum, P. corallorhiza and P. suhrii that possess interesting cytotoxicities against a breast cancer cell line (MCF7) and an oesophageal cancer line (WHCO1). The aim of the project was therefore centred at isolating target compounds for preliminary structure-activity studies against a breast cancer cell line, and use this information to synthesize a series of analogues that are more stable than the natural products and yet as active using a fragment-based type approach to map out pharmacophoric elements. Five metabolites were isolated from P. cornutum and five from P. corallorhiza. Cell-based assays were conducted using an MTT assay kit against MCF7 and MDA-MB-231 breast cancer cell lines and (1E,3E,5S,6R)-1,5,6-trichloro-2-(dichloromethyl)-6-methylocta-1,3,7-triene, isolated from P. cornutum was the most active with IC50 values of 3.0 μM and 6.15 μM respectively. Introduction of a terminal aromatic ring to enhance stability, together with varying substituents (H, CH3, CF3, Br, CN, CHO, CHCl2) on position 7 of the molecule, gave rise to a series of cinnamate ester derivatives inspired by (1E,3E,5S,6R)-1,5,6-trichloro-2-(dichloromethyl)-6-methylocta-1,3,7-triene. The analogues were synthesized from their benzaldehyde precursors via Aldol condensation, esterification and Wittig reactions. Their carboxylic acid counterparts were synthesized by hydrolysis of the parent esters in an attempt to promote water solubilities of the analogues. Biological activity assays were then conducted with the cinnamate analogues against the MDA-MB-231 breast cancer cell line using an MTT assay kit. Ester derivatives with -CHO and -CHCl2 functionalities had IC50 values of 43.45 μM and 100.01 μM respectively whilst the other ester derivatives were inactive. It was concluded that either an aldehyde (-CHO) or gem-dichlorides (-CHCl2) is specifically required for cytotoxic activity to be observed. None of the carboxylic acids were active which could have been due to failure of the compounds to enter the breast cancer cells and reach the target site because of their polar nature. Compounds with -CHO and -CHCl2 functionalities were therefore selected for future SARs studies.
- Full Text:
- Date Issued: 2012
A process-genre approach to teaching argumentative writing to grade nine learners
- Authors: Elson, Jillian Margaret
- Date: 2012
- Subjects: English language -- Rhetoric -- Study and teaching (Secondary) English language -- Writing -- Study and teaching (Secondary) Written communication
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1714 , http://hdl.handle.net/10962/d1003597
- Description: This action research study aimed to improve teaching and learning of argumentative writing through a process-genre approach. Learners were carefully guided through the processes of writing the argumentative genre, with the focus being on teaching of the genre and on the structural conventions of writing arguments. Participants were a class of grade nine learners who speak English as a first language. They were chosen for this study as Grade Nine is a crucial year for writing development before learners enter the senior phase and are met with heightened expectations in the curriculum, that often they struggle to meet, as their writing has not been sufficiently developed to an academic level. The focus of writing in Grade Nine is on narrative and prose, so this writing intervention, in which a teaching module was developed in collaboration with the 1eamers, aimed to broaden their writing skills and provide them with a head start in leaming the fine art of argumentation, as this is a useful skill to acquire for purposes even beyond the classroom. Genre theorists advocate the importance of teaching genres to leamers at a young age, as it allows them access into different communities of discourse, as they become aware and understand the conventions held by a patiicular community, and realize the purpose of different styles of writing for effectively communicating, which prepares them to meet the expectations of their audience. Teaching the structures of different genres therefore allows the writer, and the audience, a framework for understanding the text. The process approach has been widely used by educators as it focuses on explicit teaching of writing processes that are fundamental to leamers' development in writing. Learners need to be carefully guided from the initial stages, to the more complex stages (especially in argumentative writing which has been deemed the most complex genre for learners to master) in order to understand the complexities of constructing an essay in a cohesive way, as they need to consider multiple aspects of writing, such as the linguistic features, rhetorical features and structural features of the genre and unify them into a sound argument. This takes time, practice and revision, and extensive feedback is required. The process-genre approach proved to be successful in this study, as leamers showed remarkable improvements in their writing from the initial stages of writing to the final drafts of their essays. The findings revealed that explicit teaching of genres and structural elements of writing is vital for ensuring learners' development. Learners require modelling of the genre, scaffolding and careful guidance through step-by-step processes in order to build confidence and express their ideas effectively in written text. The findings indicate the relevance of using the process-genre approach for teaching and learning and that teaching and learning writing is indeed a process that needs more time and practice that is cUiTently allocated in the curriculum.
- Full Text:
- Date Issued: 2012
- Authors: Elson, Jillian Margaret
- Date: 2012
- Subjects: English language -- Rhetoric -- Study and teaching (Secondary) English language -- Writing -- Study and teaching (Secondary) Written communication
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1714 , http://hdl.handle.net/10962/d1003597
- Description: This action research study aimed to improve teaching and learning of argumentative writing through a process-genre approach. Learners were carefully guided through the processes of writing the argumentative genre, with the focus being on teaching of the genre and on the structural conventions of writing arguments. Participants were a class of grade nine learners who speak English as a first language. They were chosen for this study as Grade Nine is a crucial year for writing development before learners enter the senior phase and are met with heightened expectations in the curriculum, that often they struggle to meet, as their writing has not been sufficiently developed to an academic level. The focus of writing in Grade Nine is on narrative and prose, so this writing intervention, in which a teaching module was developed in collaboration with the 1eamers, aimed to broaden their writing skills and provide them with a head start in leaming the fine art of argumentation, as this is a useful skill to acquire for purposes even beyond the classroom. Genre theorists advocate the importance of teaching genres to leamers at a young age, as it allows them access into different communities of discourse, as they become aware and understand the conventions held by a patiicular community, and realize the purpose of different styles of writing for effectively communicating, which prepares them to meet the expectations of their audience. Teaching the structures of different genres therefore allows the writer, and the audience, a framework for understanding the text. The process approach has been widely used by educators as it focuses on explicit teaching of writing processes that are fundamental to leamers' development in writing. Learners need to be carefully guided from the initial stages, to the more complex stages (especially in argumentative writing which has been deemed the most complex genre for learners to master) in order to understand the complexities of constructing an essay in a cohesive way, as they need to consider multiple aspects of writing, such as the linguistic features, rhetorical features and structural features of the genre and unify them into a sound argument. This takes time, practice and revision, and extensive feedback is required. The process-genre approach proved to be successful in this study, as leamers showed remarkable improvements in their writing from the initial stages of writing to the final drafts of their essays. The findings revealed that explicit teaching of genres and structural elements of writing is vital for ensuring learners' development. Learners require modelling of the genre, scaffolding and careful guidance through step-by-step processes in order to build confidence and express their ideas effectively in written text. The findings indicate the relevance of using the process-genre approach for teaching and learning and that teaching and learning writing is indeed a process that needs more time and practice that is cUiTently allocated in the curriculum.
- Full Text:
- Date Issued: 2012
The role of Hsp90/Hsp70 organising protein (Hop) in the Proliferation, Survival and Migration of Breast Cancer Cells.
- Authors: Willmer, Tarryn
- Date: 2012
- Subjects: Cancer -- Treatment , Heat shock proteins , Cancer cells , Breast -- Cancer
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4130 , http://hdl.handle.net/10962/d1015720
- Description: Hop (the Hsp90/Hsp70 organising protein) is a co-chaperone that acts as an adapter between the major molecular chaperones Hsp90 and Hsp70 during the cellular assembly of the Hsp90 complex. The Hsp90 complex regulates the stability and conformational maturation of a range of important cellular proteins, many of which are deregulated in cancer. In this study, we hypothesised that Hop knockdown inhibits proliferation and migration of cancer cells. We characterised the expression of Hop in cell models of different cancerous status, and provided evidence that Hop was upregulated in tumour cells compared to normal cell counterparts. Using an RNA interference approach, a 60-90% knockdown of Hop was achieved for up to 144 hours in the MDA-MB-231 and Hs578T breast cancer cell lines. Hop knockdown resulted in downregulation of the Hsp90 client proteins, Akt and Stat3, as well as a change in the expression of other Hsp90 co-chaperones, p23, Cdc37 and Aha1, while no change in the levels of Hsp90 or Hsp70 was observed. Silencing of Hop impaired cell proliferation in Hs578T cells but an increase in proliferation in MDA-MB-231, suggesting that the role of Hop in cancer cell proliferation was dependent on type of cancer cell. Hop knockdown in Hs578T and MDA-MB- 231 cells did not lead to any significant changes in the half maximal inhibitory concentrations (IC50) of selected small molecule inhibitors (paclitaxel, geldanamycin and novobiocin) in these cell lines after 72 hours. Hop knockdown cells were however, more sensitive than control cells to the Hsp90 inhibitors geldanamycin and novobiocin at earlier time points and in the presence of the drug transporter inhibitor, verapamil. Hop knockdown caused a decrease in cell migration as measured by the wound healing assay in both Hs578T and MDA-MB-231 cells. Hop was present in purified pseudopodia fractions of migrating cells, and immunofluorescence analysis showed that Hop colocalised with actin at the leading edges of pseudopodia, points of adhesion and at intercellular junctions of cells that have been stimulated to migrate with the chemokine stromal derived factor-1. Hop was able to bind to actin in vitro using actin cosedimentation assays, and silencing of Hop dramatically reduced the capacity of Hs578T cells to form pseudopodia. These results establish a correlation between Hop and actin dynamics, pseudopodia formation and migration in the context of Hop silencing, and collectively suggest that Hop plays a role in cancer cell migration. This study presents experimental evidence for a promising alternative to targeting Hsp90 and Hsp70 chaperones, a novel drug target in cancer therapy.
- Full Text:
- Date Issued: 2012
- Authors: Willmer, Tarryn
- Date: 2012
- Subjects: Cancer -- Treatment , Heat shock proteins , Cancer cells , Breast -- Cancer
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4130 , http://hdl.handle.net/10962/d1015720
- Description: Hop (the Hsp90/Hsp70 organising protein) is a co-chaperone that acts as an adapter between the major molecular chaperones Hsp90 and Hsp70 during the cellular assembly of the Hsp90 complex. The Hsp90 complex regulates the stability and conformational maturation of a range of important cellular proteins, many of which are deregulated in cancer. In this study, we hypothesised that Hop knockdown inhibits proliferation and migration of cancer cells. We characterised the expression of Hop in cell models of different cancerous status, and provided evidence that Hop was upregulated in tumour cells compared to normal cell counterparts. Using an RNA interference approach, a 60-90% knockdown of Hop was achieved for up to 144 hours in the MDA-MB-231 and Hs578T breast cancer cell lines. Hop knockdown resulted in downregulation of the Hsp90 client proteins, Akt and Stat3, as well as a change in the expression of other Hsp90 co-chaperones, p23, Cdc37 and Aha1, while no change in the levels of Hsp90 or Hsp70 was observed. Silencing of Hop impaired cell proliferation in Hs578T cells but an increase in proliferation in MDA-MB-231, suggesting that the role of Hop in cancer cell proliferation was dependent on type of cancer cell. Hop knockdown in Hs578T and MDA-MB- 231 cells did not lead to any significant changes in the half maximal inhibitory concentrations (IC50) of selected small molecule inhibitors (paclitaxel, geldanamycin and novobiocin) in these cell lines after 72 hours. Hop knockdown cells were however, more sensitive than control cells to the Hsp90 inhibitors geldanamycin and novobiocin at earlier time points and in the presence of the drug transporter inhibitor, verapamil. Hop knockdown caused a decrease in cell migration as measured by the wound healing assay in both Hs578T and MDA-MB-231 cells. Hop was present in purified pseudopodia fractions of migrating cells, and immunofluorescence analysis showed that Hop colocalised with actin at the leading edges of pseudopodia, points of adhesion and at intercellular junctions of cells that have been stimulated to migrate with the chemokine stromal derived factor-1. Hop was able to bind to actin in vitro using actin cosedimentation assays, and silencing of Hop dramatically reduced the capacity of Hs578T cells to form pseudopodia. These results establish a correlation between Hop and actin dynamics, pseudopodia formation and migration in the context of Hop silencing, and collectively suggest that Hop plays a role in cancer cell migration. This study presents experimental evidence for a promising alternative to targeting Hsp90 and Hsp70 chaperones, a novel drug target in cancer therapy.
- Full Text:
- Date Issued: 2012
An investigation into the benefits of integrating learners' prior everyday knowledge and experiences during teaching and learning of acids and bases in Grade 7: a case study
- Authors: Kuhlane, Zukiswa
- Date: 2012
- Subjects: Science -- Study and teaching (Primary) -- Research -- South Africa Prior learning -- South Africa Limited English-proficient students -- Education (Primary) -- South Africa Teaching -- Aids and devices -- Research
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1602 , http://hdl.handle.net/10962/d1003484
- Description: This study was conducted at a school designated as a higher primary school comprised of grade 0-9 learners (GET band) in Grahamstown in the Eastern Cape, South Africa. With the advent of the new curriculum in South Africa, we are also grappling with the implementation of the new curriculum at this school. This motivated me to investigate the benefits of eliciting and integrating learners’ prior everyday knowledge and experiences during teaching and learning of acids and bases. Essentially, the study sought to gain insight into whether engaging learners during practical activities using easily accessible materials from their homes facilitated meaning-making of acids and bases. This study is located within an interpretive paradigm. Within this paradigm, a qualitative case study approach was conducted with the researcher’s Grade 7 class. To gather data, document analysis, semi-structured interviews, questionnaires, lesson observations, stimulated recall discussions while watching the videotaped lessons as well as focus group interviews with learners were used. An inductive analysis to discover patterns and themes was applied during the data analysis process. The validation process was done through watching the videotaped lessons with the teachers who observed the lessons. Also, transcripts of the interviews and a summary of discussions were given back to the respondents to verify their responses and check for any misinterpretations. Rich data sets were analysed in relation to the research questions which were: How do Natural Sciences teachers elicit and integrate learners’ prioreveryday knowledge and experiences to facilitate learning of scientific concepts of acids and bases in their classrooms? Does engaging learners in practical activities using everyday substances enhance their conceptual development and understanding of acids and bases? The findings from the study revealed that the use of learners’ prior everyday knowledge and experiences during teaching and learning of acids and bases facilitated meaningful learning. Furthermore, linking learning to learners’ everyday experiences enabled them to learn scientific concepts in a relaxed and non-threatening environment. It is thus recommended that teachers should be supported in their endeavours to incorporate learners’ real life experiences during their teaching and learning repertoires. Notwithstanding, as much as there were benefits in this study there were, however, also some challenges that were encountered, such as language, which warrants further research.
- Full Text:
- Date Issued: 2012
- Authors: Kuhlane, Zukiswa
- Date: 2012
- Subjects: Science -- Study and teaching (Primary) -- Research -- South Africa Prior learning -- South Africa Limited English-proficient students -- Education (Primary) -- South Africa Teaching -- Aids and devices -- Research
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1602 , http://hdl.handle.net/10962/d1003484
- Description: This study was conducted at a school designated as a higher primary school comprised of grade 0-9 learners (GET band) in Grahamstown in the Eastern Cape, South Africa. With the advent of the new curriculum in South Africa, we are also grappling with the implementation of the new curriculum at this school. This motivated me to investigate the benefits of eliciting and integrating learners’ prior everyday knowledge and experiences during teaching and learning of acids and bases. Essentially, the study sought to gain insight into whether engaging learners during practical activities using easily accessible materials from their homes facilitated meaning-making of acids and bases. This study is located within an interpretive paradigm. Within this paradigm, a qualitative case study approach was conducted with the researcher’s Grade 7 class. To gather data, document analysis, semi-structured interviews, questionnaires, lesson observations, stimulated recall discussions while watching the videotaped lessons as well as focus group interviews with learners were used. An inductive analysis to discover patterns and themes was applied during the data analysis process. The validation process was done through watching the videotaped lessons with the teachers who observed the lessons. Also, transcripts of the interviews and a summary of discussions were given back to the respondents to verify their responses and check for any misinterpretations. Rich data sets were analysed in relation to the research questions which were: How do Natural Sciences teachers elicit and integrate learners’ prioreveryday knowledge and experiences to facilitate learning of scientific concepts of acids and bases in their classrooms? Does engaging learners in practical activities using everyday substances enhance their conceptual development and understanding of acids and bases? The findings from the study revealed that the use of learners’ prior everyday knowledge and experiences during teaching and learning of acids and bases facilitated meaningful learning. Furthermore, linking learning to learners’ everyday experiences enabled them to learn scientific concepts in a relaxed and non-threatening environment. It is thus recommended that teachers should be supported in their endeavours to incorporate learners’ real life experiences during their teaching and learning repertoires. Notwithstanding, as much as there were benefits in this study there were, however, also some challenges that were encountered, such as language, which warrants further research.
- Full Text:
- Date Issued: 2012
A critical realist exploration of the implementation of a new curriculum in Swaziland
- Authors: Pereira, Liphie
- Date: 2012
- Subjects: Critical realism Education -- Philosophy Critical pedagogy -- Swaziland Curriculum change -- Swaziland Education -- Swaziland Education and state -- Swaziland Education -- Aims and objectives -- Swaziland Critical discourse analysis International General Certificate of Secondary Education
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1484 , http://hdl.handle.net/10962/d1003365
- Description: This study offers an in-depth exploration of the conditions from which the implementation of a curriculum called the International General Certificate of Secondary Education (IGCSE), later localised into Swaziland General Certificate of Secondary Education (SGCSE), emerged and the constraining and enabling conditions for the implementation of the new I/SGCSE curriculum. It derives its theoretical foundation from Roy Bhaskar’s critical realism and Margaret Archer’s concept of analytical separability. The study therefore offers explanations about the curriculum change and its implementation that are based on how structural, cultural, and agential mechanisms operating at a deeper level of reality (the intransitive layer of reality or the domain of the real) and existing independently of what we see, know or believe of them (the transitive layer of reality or domains of the actual and empirical) interacted to condition the emergence of I/SGCSE and the way it is implemented. I conduct a critical discourse analysis of relevant literature, I/SGCSE documents and interview data in order to identify those mechanisms that were cultural and also those that were structural and agential. Bernstein’s concepts of classification and framing are used to analyse observation data in order to explore the influence of these mechanisms on the teaching practices of the teachers who took part in the study. Analysis of the data suggests that the change from General Certificate of Education Ordinary Level (GCE O-level) to I/SGCSE was conditioned by inconsistencies between the cultural and structural mechanisms of the Swazi context. Many of the cultural elements of the Swazi context such as the discourses of good citizens, of competitive advantage, and of quality education draw from global discourses which view relations between people from a postmodernist position and therefore support weakly classified and framed pedagogic practices. In contrast, the discourse of morality and many of the structural elements of the Swazi context, such as the pre2006 education system and the Tinkhundla government system, all view reality from a modernist position, therefore supporting strong relations of power and control. The cultural system therefore exerted more influence in conditioning the change from the strongly classified and framed GCE O-level curriculum to the weakly classified and framed I/SGCSE curriculum. Furthermore, the analysis of interview and observation data suggests that inconsistencies between the global discourses and the discourses and structures that teachers confront in their day-to-day lives, together with the decisions teachers made in response to structural constraints, created constraining conditions for the change from GCE O-level to I/SGCSE. The study adds to knowledge on curriculum change and implementation through insights into the enabling and constraining effects of mechanisms operating at a deeper level of reality on curriculum-change decisions and on the ability of teachers to implement curriculum changes. The focus on the deeper level of reality may therefore contribute towards emancipatory knowledge which could be used not only by the Ministry of Education and Training and teachers in Swaziland but also elsewhere to inform future planning, decision making, and practice in relation to curriculum change and implementation.
- Full Text:
- Date Issued: 2012
- Authors: Pereira, Liphie
- Date: 2012
- Subjects: Critical realism Education -- Philosophy Critical pedagogy -- Swaziland Curriculum change -- Swaziland Education -- Swaziland Education and state -- Swaziland Education -- Aims and objectives -- Swaziland Critical discourse analysis International General Certificate of Secondary Education
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1484 , http://hdl.handle.net/10962/d1003365
- Description: This study offers an in-depth exploration of the conditions from which the implementation of a curriculum called the International General Certificate of Secondary Education (IGCSE), later localised into Swaziland General Certificate of Secondary Education (SGCSE), emerged and the constraining and enabling conditions for the implementation of the new I/SGCSE curriculum. It derives its theoretical foundation from Roy Bhaskar’s critical realism and Margaret Archer’s concept of analytical separability. The study therefore offers explanations about the curriculum change and its implementation that are based on how structural, cultural, and agential mechanisms operating at a deeper level of reality (the intransitive layer of reality or the domain of the real) and existing independently of what we see, know or believe of them (the transitive layer of reality or domains of the actual and empirical) interacted to condition the emergence of I/SGCSE and the way it is implemented. I conduct a critical discourse analysis of relevant literature, I/SGCSE documents and interview data in order to identify those mechanisms that were cultural and also those that were structural and agential. Bernstein’s concepts of classification and framing are used to analyse observation data in order to explore the influence of these mechanisms on the teaching practices of the teachers who took part in the study. Analysis of the data suggests that the change from General Certificate of Education Ordinary Level (GCE O-level) to I/SGCSE was conditioned by inconsistencies between the cultural and structural mechanisms of the Swazi context. Many of the cultural elements of the Swazi context such as the discourses of good citizens, of competitive advantage, and of quality education draw from global discourses which view relations between people from a postmodernist position and therefore support weakly classified and framed pedagogic practices. In contrast, the discourse of morality and many of the structural elements of the Swazi context, such as the pre2006 education system and the Tinkhundla government system, all view reality from a modernist position, therefore supporting strong relations of power and control. The cultural system therefore exerted more influence in conditioning the change from the strongly classified and framed GCE O-level curriculum to the weakly classified and framed I/SGCSE curriculum. Furthermore, the analysis of interview and observation data suggests that inconsistencies between the global discourses and the discourses and structures that teachers confront in their day-to-day lives, together with the decisions teachers made in response to structural constraints, created constraining conditions for the change from GCE O-level to I/SGCSE. The study adds to knowledge on curriculum change and implementation through insights into the enabling and constraining effects of mechanisms operating at a deeper level of reality on curriculum-change decisions and on the ability of teachers to implement curriculum changes. The focus on the deeper level of reality may therefore contribute towards emancipatory knowledge which could be used not only by the Ministry of Education and Training and teachers in Swaziland but also elsewhere to inform future planning, decision making, and practice in relation to curriculum change and implementation.
- Full Text:
- Date Issued: 2012
Farm level institutions in emergent communities in post fast track Zimbabwe: case of Mazowe district
- Authors: Chiweshe, Manase Kudzai
- Date: 2012
- Subjects: Land reform -- Zimbabwe -- History -- 21st century Land settlement -- Social aspects -- Zimbabwe Zimbabwe -- Social conditions -- 1980- Zimbabwe -- Economic conditions Zimbabwe -- Politics and government -- 1980-
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3308 , http://hdl.handle.net/10962/d1003096
- Description: The thesis seeks to understand how emerging communities borne out of the Fast Track Land Reform Programme in Zimbabwe have been able to ensure social cohesion and social service provision using farm level institutions. The Fast Track Programme brought together people from diverse backgrounds into new communities in the former commercial farming areas. The formation of new communities meant that, often, there were 'stranger households'living next to each other. Since 2000, these people have been involved in various processes aimed at turning clusters of homesteads into functioning communities through farm level institutions. Fast track land reform precipitated economic and political crisis in Zimbabwe characterised by a rapidly devaluating Zimbabwean dollar, enormous inflation and high unemployment figures. This economic crisis has impacted heavily on new farmers who find it increasingly difficult to afford inputs and access loans. They have formed social networks in response to these challenges, taking the form of farm level institutions such as farm committees, irrigation committees and health committees. The study uses case studies from small-scale 'A1 farmers‘ in Mazowe district which is in Mashonaland Central Province. It employs qualitative methodologies to enable a nuanced understanding of associational life in the new communities. Through focus group discussions, in-depth interviews, narratives, key informant interviews and institutional mapping the study outlines the formation, taxonomy, activities, roles, internal dynamics and social organisation of farm level institutions. The study also uses secondary data collected in 2007-08 by the Centre for Rural Development in the newly resettled areas in Mazowe. The major finding of the study is that farmers are organising in novel ways at grassroots levels to meet everyday challenges. These institutional forms however are internally weak, lacking leadership with a clear vision and they appear as if they are transitory in nature. They remain marginalised from national and global processes and isolated from critical connections to policy makers at all levels; thus A1 farmers remain voiceless and unable to have their interests addressed. Farm level institutions are at the forefront of the microeconomics of survival among these rural farmers. They are survivalist in nature and form, and this requires a major shift in focus if they are to be involved in developmental work. The institutions remain fragmented and compete amongst themselves for services from government without uniting as A1 farmers with similar interests and challenges.
- Full Text:
- Date Issued: 2012
Farm level institutions in emergent communities in post fast track Zimbabwe: case of Mazowe district
- Authors: Chiweshe, Manase Kudzai
- Date: 2012
- Subjects: Land reform -- Zimbabwe -- History -- 21st century Land settlement -- Social aspects -- Zimbabwe Zimbabwe -- Social conditions -- 1980- Zimbabwe -- Economic conditions Zimbabwe -- Politics and government -- 1980-
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3308 , http://hdl.handle.net/10962/d1003096
- Description: The thesis seeks to understand how emerging communities borne out of the Fast Track Land Reform Programme in Zimbabwe have been able to ensure social cohesion and social service provision using farm level institutions. The Fast Track Programme brought together people from diverse backgrounds into new communities in the former commercial farming areas. The formation of new communities meant that, often, there were 'stranger households'living next to each other. Since 2000, these people have been involved in various processes aimed at turning clusters of homesteads into functioning communities through farm level institutions. Fast track land reform precipitated economic and political crisis in Zimbabwe characterised by a rapidly devaluating Zimbabwean dollar, enormous inflation and high unemployment figures. This economic crisis has impacted heavily on new farmers who find it increasingly difficult to afford inputs and access loans. They have formed social networks in response to these challenges, taking the form of farm level institutions such as farm committees, irrigation committees and health committees. The study uses case studies from small-scale 'A1 farmers‘ in Mazowe district which is in Mashonaland Central Province. It employs qualitative methodologies to enable a nuanced understanding of associational life in the new communities. Through focus group discussions, in-depth interviews, narratives, key informant interviews and institutional mapping the study outlines the formation, taxonomy, activities, roles, internal dynamics and social organisation of farm level institutions. The study also uses secondary data collected in 2007-08 by the Centre for Rural Development in the newly resettled areas in Mazowe. The major finding of the study is that farmers are organising in novel ways at grassroots levels to meet everyday challenges. These institutional forms however are internally weak, lacking leadership with a clear vision and they appear as if they are transitory in nature. They remain marginalised from national and global processes and isolated from critical connections to policy makers at all levels; thus A1 farmers remain voiceless and unable to have their interests addressed. Farm level institutions are at the forefront of the microeconomics of survival among these rural farmers. They are survivalist in nature and form, and this requires a major shift in focus if they are to be involved in developmental work. The institutions remain fragmented and compete amongst themselves for services from government without uniting as A1 farmers with similar interests and challenges.
- Full Text:
- Date Issued: 2012
Rapid enzymatic detection of organophosphorous and carbamate pesticides in water
- Authors: Mwila, Katayi
- Date: 2012
- Subjects: Organophosphorus compounds , Carbamates , Water -- Pesticide content -- South Africa -- Eastern Cape , Water quality biological assessment -- South Africa -- Eastern Cape , Water quality management -- South Africa -- Eastern Cape , Pesticides -- Toxicology -- South Africa -- Eastern Cape , Biological assay , Acetylcholinesterase , Parathion , Aldicarb , Carbaryl , Carbofuran , Nitrophenols
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4024 , http://hdl.handle.net/10962/d1004084 , Organophosphorus compounds , Carbamates , Water -- Pesticide content -- South Africa -- Eastern Cape , Water quality biological assessment -- South Africa -- Eastern Cape , Water quality management -- South Africa -- Eastern Cape , Pesticides -- Toxicology -- South Africa -- Eastern Cape , Biological assay , Acetylcholinesterase , Parathion , Aldicarb , Carbaryl , Carbofuran , Nitrophenols
- Description: The increased use of pesticides has resulted in a corresponding increase in concern for the effect they may have on the health of humans and other non-target organisms. The two main areas of concern are the toxicological effects that mixtures of pesticides may have as well as the endocrine disrupting effects. Although the individual pesticides may be present at concentrations below the levels deemed to be detrimental to health, it has been argued that their combined effect may still result in elevated health risks. Another important aspect of pesticide risk assessment requires a consideration of the breakdown products of pesticides and their effect on human health. There has been very little research into the effects of degradation products and this issue should be addressed as these could potentially pose a higher risk than their parent compounds. One of the most important bio-markers available for use is the ubiquitous enzyme acetylcholinesterase (AChE). This enzyme is responsible for one of the most important functions in the body; namely nerve impulse transmission, upon which all life depends. The inhibition of this enzyme indicates toxicity and as a subsequence, a threat to the organism’s well-being. Bioassays have also recently been developed to test chemicals for endocrine disrupting effects. These tests rely on a dose response equivalent to that of the most potent well known estrogen 17-β estradiol. Any chemical that has a measurable response is deemed to display endocrine disrupting effects. This first aim of this study was to investigate the toxicological and endocrine disrupting effects of three organophosphorus pesticides; aldicarb, parathion and demeton-S-methyl, in addition to two breakdown products; aminophenol and p-nitrophenol. Two carbamate pesticides; carbaryl and carbofuran were also analysed. The toxicological effects of mixtures of the parent pesticide compounds were tested to assess if any antagonistic, additive or synergistic effects were observed. This data was then used in conjunction with an artificial neural network to assess if individual pesticides could be distinguished from mixtures of pesticides. A final objective was to sample various Eastern Cape water sources, utilising the enzymatic assay to determine the presence of any of these pesticides in these samples. There were several conclusions drawn from this study. AChE was successfully used as an assay to test the toxicity of the pesticides under investigation, based on their inhibition of this enzyme. An important factor for consideration throughout the study was the need to establish basal and monitor AChE activity (i.e. the need to monitor AChE activity in the absence of any pesticide). This ensured accurate comparison of the results obtained. It was found that demeton-S-methyl was the most potent of these pesticides followed by carbaryl, parathion, aldicarb and finally carbofuran, and that carbofuran could potentiate AChE. The results indicated that pesticide mixtures generally exhibited an additive inhibitory effect on AChE, although at some concentrations of pesticides, synergistic and antagonistic effects were noted. From the data using mixtures of pesticides, a feed forward neural network was created that was successfully able to distinguish individual pesticides from mixtures within its training parameters. None of the pesticides tested displayed endocrine disrupting properties in the Yeast Estrogen Screen (YES), T47D-KBluc and MDA-kb2 bio-assays. Other studies reported mixed results in this regard and thus no final conclusions could be drawn. The Blaauwkrantz River, Kariega River, Sundays River, Swartkops River and Kowie River were all tested for pesticides and although positive results were recorded, conventional methods indicated that there were no pesticides in the rivers. There were, however, trace metals present which are known to inhibit AChE, thus causing a false positive result. These results indicated that AChE can be used as a high throughput initial pre-screening tool, but that it cannot serve as a substitute for more accurate conventional testing methods.
- Full Text:
- Date Issued: 2012
- Authors: Mwila, Katayi
- Date: 2012
- Subjects: Organophosphorus compounds , Carbamates , Water -- Pesticide content -- South Africa -- Eastern Cape , Water quality biological assessment -- South Africa -- Eastern Cape , Water quality management -- South Africa -- Eastern Cape , Pesticides -- Toxicology -- South Africa -- Eastern Cape , Biological assay , Acetylcholinesterase , Parathion , Aldicarb , Carbaryl , Carbofuran , Nitrophenols
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4024 , http://hdl.handle.net/10962/d1004084 , Organophosphorus compounds , Carbamates , Water -- Pesticide content -- South Africa -- Eastern Cape , Water quality biological assessment -- South Africa -- Eastern Cape , Water quality management -- South Africa -- Eastern Cape , Pesticides -- Toxicology -- South Africa -- Eastern Cape , Biological assay , Acetylcholinesterase , Parathion , Aldicarb , Carbaryl , Carbofuran , Nitrophenols
- Description: The increased use of pesticides has resulted in a corresponding increase in concern for the effect they may have on the health of humans and other non-target organisms. The two main areas of concern are the toxicological effects that mixtures of pesticides may have as well as the endocrine disrupting effects. Although the individual pesticides may be present at concentrations below the levels deemed to be detrimental to health, it has been argued that their combined effect may still result in elevated health risks. Another important aspect of pesticide risk assessment requires a consideration of the breakdown products of pesticides and their effect on human health. There has been very little research into the effects of degradation products and this issue should be addressed as these could potentially pose a higher risk than their parent compounds. One of the most important bio-markers available for use is the ubiquitous enzyme acetylcholinesterase (AChE). This enzyme is responsible for one of the most important functions in the body; namely nerve impulse transmission, upon which all life depends. The inhibition of this enzyme indicates toxicity and as a subsequence, a threat to the organism’s well-being. Bioassays have also recently been developed to test chemicals for endocrine disrupting effects. These tests rely on a dose response equivalent to that of the most potent well known estrogen 17-β estradiol. Any chemical that has a measurable response is deemed to display endocrine disrupting effects. This first aim of this study was to investigate the toxicological and endocrine disrupting effects of three organophosphorus pesticides; aldicarb, parathion and demeton-S-methyl, in addition to two breakdown products; aminophenol and p-nitrophenol. Two carbamate pesticides; carbaryl and carbofuran were also analysed. The toxicological effects of mixtures of the parent pesticide compounds were tested to assess if any antagonistic, additive or synergistic effects were observed. This data was then used in conjunction with an artificial neural network to assess if individual pesticides could be distinguished from mixtures of pesticides. A final objective was to sample various Eastern Cape water sources, utilising the enzymatic assay to determine the presence of any of these pesticides in these samples. There were several conclusions drawn from this study. AChE was successfully used as an assay to test the toxicity of the pesticides under investigation, based on their inhibition of this enzyme. An important factor for consideration throughout the study was the need to establish basal and monitor AChE activity (i.e. the need to monitor AChE activity in the absence of any pesticide). This ensured accurate comparison of the results obtained. It was found that demeton-S-methyl was the most potent of these pesticides followed by carbaryl, parathion, aldicarb and finally carbofuran, and that carbofuran could potentiate AChE. The results indicated that pesticide mixtures generally exhibited an additive inhibitory effect on AChE, although at some concentrations of pesticides, synergistic and antagonistic effects were noted. From the data using mixtures of pesticides, a feed forward neural network was created that was successfully able to distinguish individual pesticides from mixtures within its training parameters. None of the pesticides tested displayed endocrine disrupting properties in the Yeast Estrogen Screen (YES), T47D-KBluc and MDA-kb2 bio-assays. Other studies reported mixed results in this regard and thus no final conclusions could be drawn. The Blaauwkrantz River, Kariega River, Sundays River, Swartkops River and Kowie River were all tested for pesticides and although positive results were recorded, conventional methods indicated that there were no pesticides in the rivers. There were, however, trace metals present which are known to inhibit AChE, thus causing a false positive result. These results indicated that AChE can be used as a high throughput initial pre-screening tool, but that it cannot serve as a substitute for more accurate conventional testing methods.
- Full Text:
- Date Issued: 2012
The effect of dietary fish oil replacement with soybean oil on growth and health of dusky kob, Argyrosomus japonicus (Pisces: Sciaenidae)
- Authors: Rossetti, Nani Adami
- Date: 2012
- Subjects: Sciaenidae , Fish culture , Argyrosomus -- Growth , Argyrosomus -- Feeding and feeds , Argyrosomus -- Health , Fish oils as feed , Soy oil , Lipids , Eicosapentaenoic acid , Docosahexaenoic acid
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5272 , http://hdl.handle.net/10962/d1005116 , Sciaenidae , Fish culture , Argyrosomus -- Growth , Argyrosomus -- Feeding and feeds , Argyrosomus -- Health , Fish oils as feed , Soy oil , Lipids , Eicosapentaenoic acid , Docosahexaenoic acid
- Description: Lipids are essential components for fish because they contain fatty acids that are vital for regular growth and health. Fish oil is rich in eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), which are essential fatty acids for carnivorous fish, and therefore this product has traditionally been used as the main source of lipids in fish feeds. However, with declining fisheries resources worldwide and the rapid expansion of the aquaculture industry pressuring this finite resource, such ingredients are becoming less available and more expensive. It is therefore necessary to explore the utilization of ingredients that are sustainable and competitive alternatives to fish oil in marine finfish feeds. This work investigated the effects of the substitution of fish oil with soybean oil on the growth performance, feed efficiency, fatty acid composition of the liver tissue and some health parameters in juvenile dusky kob, Argyrosomus japonicus; an increasingly popular sciaenid marine aquaculture species in South Africa. Six diets (18 % total lipid and 46 % protein) with increasing percentage substitution of fish oil with soybean oil (1, 14, 28, 42, 56 and 70 %) were fed to juvenile kob. After 84 days of feeding these diets to the fish, no significant differences in fish length and weight between treatments were observed. However, there was a significant trend of a decrease in specific growth rate, ranging from (± standard error) 0.87 ± 0.06 to 0.72 ± 0.04 % body weight day⁻¹, and condition factor, ranging from 1.59 ± 0.03 to 1.54 ± 0.02, with increasing vegetable oil replacement in the diets between days 56 and 84. There were no differences in red blood cell count, haematocrit and haemoglobin concentration after 206 days of feeding. However, visceral fat index (VFI) increased significantly from 1.08 ± 0.17 % for fish fed diets with 28 % soybean oil, to 2.24 ± 0.15 % for fish fed diets with 70 % soybean oil. Similarly, hepatosomatic index (HSI) increased significantly from 0.84 ± 0.08 % to 1.80 ± 0.12 % in the control diet and the 56 % soybean oil diet, respectively. After 206 days of feeding, fish fed diets with 42 to 70 % soybean oil showed greater number of lipid vacuoles in the liver, which were also larger in size, and hepatocytes nuclei were displaced to the cell periphery. The fatty acid composition of the liver tissue strongly corresponded to the fatty acid composition of the diets. Linoleic acid accumulated in the liver of the fish fed increasing soybean oil in the diets. In contrast, EPA and DHA decreased from 13.63 to 1.97 %, and 14.34 to 3.28 %, respectively, in the liver tissue of fish fed diets with increasing soybean oil content; consequently the n-3/n-6 ratio was also significantly reduced with inclusion of vegetable oil in the diets. The trend of decreasing growth rate with increasing oil replacement towards the end of the trial corresponds with increases in VFI, HSI, as well as the fatty acid accumulation and lipid vacuoles in the liver. This suggests that dusky kob is less able to metabolise soybean oil at increased substitution levels which would account for the poorer growth at higher levels. The dependence of fish on dietary marine oil decreased significantly with each inclusion of soybean oil in the diets. Nonetheless, the calculations based on the nutrient ratio presented positive outcomes for all treatments, that is, values of marine oil dependency ratio were below one for all treatments. It is concluded that soybean oil can replace fish oil in formulated diets for dusky kob up to a level of 28 % of total dietary lipids, as evidenced by the good growth and feed efficiency, and no apparent negative health effects observed up to this level.
- Full Text:
- Date Issued: 2012
- Authors: Rossetti, Nani Adami
- Date: 2012
- Subjects: Sciaenidae , Fish culture , Argyrosomus -- Growth , Argyrosomus -- Feeding and feeds , Argyrosomus -- Health , Fish oils as feed , Soy oil , Lipids , Eicosapentaenoic acid , Docosahexaenoic acid
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5272 , http://hdl.handle.net/10962/d1005116 , Sciaenidae , Fish culture , Argyrosomus -- Growth , Argyrosomus -- Feeding and feeds , Argyrosomus -- Health , Fish oils as feed , Soy oil , Lipids , Eicosapentaenoic acid , Docosahexaenoic acid
- Description: Lipids are essential components for fish because they contain fatty acids that are vital for regular growth and health. Fish oil is rich in eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), which are essential fatty acids for carnivorous fish, and therefore this product has traditionally been used as the main source of lipids in fish feeds. However, with declining fisheries resources worldwide and the rapid expansion of the aquaculture industry pressuring this finite resource, such ingredients are becoming less available and more expensive. It is therefore necessary to explore the utilization of ingredients that are sustainable and competitive alternatives to fish oil in marine finfish feeds. This work investigated the effects of the substitution of fish oil with soybean oil on the growth performance, feed efficiency, fatty acid composition of the liver tissue and some health parameters in juvenile dusky kob, Argyrosomus japonicus; an increasingly popular sciaenid marine aquaculture species in South Africa. Six diets (18 % total lipid and 46 % protein) with increasing percentage substitution of fish oil with soybean oil (1, 14, 28, 42, 56 and 70 %) were fed to juvenile kob. After 84 days of feeding these diets to the fish, no significant differences in fish length and weight between treatments were observed. However, there was a significant trend of a decrease in specific growth rate, ranging from (± standard error) 0.87 ± 0.06 to 0.72 ± 0.04 % body weight day⁻¹, and condition factor, ranging from 1.59 ± 0.03 to 1.54 ± 0.02, with increasing vegetable oil replacement in the diets between days 56 and 84. There were no differences in red blood cell count, haematocrit and haemoglobin concentration after 206 days of feeding. However, visceral fat index (VFI) increased significantly from 1.08 ± 0.17 % for fish fed diets with 28 % soybean oil, to 2.24 ± 0.15 % for fish fed diets with 70 % soybean oil. Similarly, hepatosomatic index (HSI) increased significantly from 0.84 ± 0.08 % to 1.80 ± 0.12 % in the control diet and the 56 % soybean oil diet, respectively. After 206 days of feeding, fish fed diets with 42 to 70 % soybean oil showed greater number of lipid vacuoles in the liver, which were also larger in size, and hepatocytes nuclei were displaced to the cell periphery. The fatty acid composition of the liver tissue strongly corresponded to the fatty acid composition of the diets. Linoleic acid accumulated in the liver of the fish fed increasing soybean oil in the diets. In contrast, EPA and DHA decreased from 13.63 to 1.97 %, and 14.34 to 3.28 %, respectively, in the liver tissue of fish fed diets with increasing soybean oil content; consequently the n-3/n-6 ratio was also significantly reduced with inclusion of vegetable oil in the diets. The trend of decreasing growth rate with increasing oil replacement towards the end of the trial corresponds with increases in VFI, HSI, as well as the fatty acid accumulation and lipid vacuoles in the liver. This suggests that dusky kob is less able to metabolise soybean oil at increased substitution levels which would account for the poorer growth at higher levels. The dependence of fish on dietary marine oil decreased significantly with each inclusion of soybean oil in the diets. Nonetheless, the calculations based on the nutrient ratio presented positive outcomes for all treatments, that is, values of marine oil dependency ratio were below one for all treatments. It is concluded that soybean oil can replace fish oil in formulated diets for dusky kob up to a level of 28 % of total dietary lipids, as evidenced by the good growth and feed efficiency, and no apparent negative health effects observed up to this level.
- Full Text:
- Date Issued: 2012
Assessing the impacts of invasive non-native African sharptooth catfish Clarias Gariepinus
- Authors: Kadye, Wilbert Takawira
- Date: 2012
- Subjects: Catfishes -- South Africa -- Eastern Cape Biological invasions -- South Africa -- Great Fish River Biological invasions -- South Africa -- Sundays River Clarias gariepinus Freshwater ecology
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5227 , http://hdl.handle.net/10962/d1005070
- Description: Invasive species are of particular concern as they have the potential to alter community structure and food web relationships within their invaded habitats. African sharptooth catfish Clarias gariepinus, a generalist predator, was introduced through an inter-basin water transfer scheme into the Great Fish and Sundays Rivers, Eastern Cape, South Africa, where it threatens the native riverine biota. This thesis assessed its impact from a trophic perspective. Patterns in catfish distribution and abundance revealed an upstream to downstream gradient that was associated with spatial distribution of most species within the mainstream, and a mainstream to tributary gradient that was associated with the spatial distribution of native minnows. The catfish was predicted to occur widely within the mainstem habitats and to decrease progressively along the mainstrem to tributary gradient with the physico-chemical environment being a good proxy for predicting both its occurrence and abundance. The results suggest the catfish proliferated within mainstem habitats where invasion resistance was possibly reduced due to alteration of flow. Population dynamics and size structuring of two native cyprinid minnows Pseudobarbus afer and Barbus anoplus, threatened by catfish, were examined within uninvaded headwater streams in relation to their proximate physical habitats. Their habitats were characterised by seasonal variation in physico-chemical conditions and a spatial variation in substrata compositions. No evidence of differences was found between seasons for density and capture probability for either species. The population size and density for P. afer was found to increase with increasing proportion of boulders. In comparison, B. anoplus population size and probability of capture increased with increasing proportion of bedrock and bank vegetation, respectively. Size structuring was explained predominantly by seasonality and habitat variables for P. afer and B. anoplus, respectively. Stable isotope ratios of carbon and nitrogen were used to compare the spatial variation in both the community-wide and catfish-specific niches and to estimate catfish prey sources from different habitats within the invaded systems. Aquatic community and catfish niches were statistically different among localities, suggesting that each locality had a distinct community-wide trophic structure. Dispersion metrics indicated no evidence of differences in the clustering among individuals, but provided evidence of differences in path trajectories for the comparisons of catfish populations that suggested dietary plasticity within different localities. Dietary studies revealed both ontogenetic shift and omnivory that suggested that catfish may exhibit less pronounced top-down effects within its invaded habitats. Manipulative experiments were used to test the response of benthic macroinvertebrates within two rivers that were differentially impacted by catfish as a presstype disturbance. Macroinvertebrates were non-responsive to catfish presence within a system where catfish had previously been established. In contrast, excluding catfish in this system indicated a response that suggested the importance of refuge within invaded habitats and the possible recovery pattern of certain macroinvertebrate taxa. By comparison, introduction of catfish within previously uninvaded localities provided evidence of direct catfish impact through elimination of conspicuous taxa. Acoustic telemetry was used to investigate catfish movement patterns within an invaded lentic habitat and provided evidence that habitat utilisation was non-random. The shallow and structured river mouth habitat, which was most utilised, was probably the most ideal for its breeding and feeding. This inferred potential overlap with native species and suggested the risk of predation and competitive interference. Catfish also exhibited both nocturnal and diurnal activity patterns that were probably related to feeding.
- Full Text:
- Date Issued: 2012
- Authors: Kadye, Wilbert Takawira
- Date: 2012
- Subjects: Catfishes -- South Africa -- Eastern Cape Biological invasions -- South Africa -- Great Fish River Biological invasions -- South Africa -- Sundays River Clarias gariepinus Freshwater ecology
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5227 , http://hdl.handle.net/10962/d1005070
- Description: Invasive species are of particular concern as they have the potential to alter community structure and food web relationships within their invaded habitats. African sharptooth catfish Clarias gariepinus, a generalist predator, was introduced through an inter-basin water transfer scheme into the Great Fish and Sundays Rivers, Eastern Cape, South Africa, where it threatens the native riverine biota. This thesis assessed its impact from a trophic perspective. Patterns in catfish distribution and abundance revealed an upstream to downstream gradient that was associated with spatial distribution of most species within the mainstream, and a mainstream to tributary gradient that was associated with the spatial distribution of native minnows. The catfish was predicted to occur widely within the mainstem habitats and to decrease progressively along the mainstrem to tributary gradient with the physico-chemical environment being a good proxy for predicting both its occurrence and abundance. The results suggest the catfish proliferated within mainstem habitats where invasion resistance was possibly reduced due to alteration of flow. Population dynamics and size structuring of two native cyprinid minnows Pseudobarbus afer and Barbus anoplus, threatened by catfish, were examined within uninvaded headwater streams in relation to their proximate physical habitats. Their habitats were characterised by seasonal variation in physico-chemical conditions and a spatial variation in substrata compositions. No evidence of differences was found between seasons for density and capture probability for either species. The population size and density for P. afer was found to increase with increasing proportion of boulders. In comparison, B. anoplus population size and probability of capture increased with increasing proportion of bedrock and bank vegetation, respectively. Size structuring was explained predominantly by seasonality and habitat variables for P. afer and B. anoplus, respectively. Stable isotope ratios of carbon and nitrogen were used to compare the spatial variation in both the community-wide and catfish-specific niches and to estimate catfish prey sources from different habitats within the invaded systems. Aquatic community and catfish niches were statistically different among localities, suggesting that each locality had a distinct community-wide trophic structure. Dispersion metrics indicated no evidence of differences in the clustering among individuals, but provided evidence of differences in path trajectories for the comparisons of catfish populations that suggested dietary plasticity within different localities. Dietary studies revealed both ontogenetic shift and omnivory that suggested that catfish may exhibit less pronounced top-down effects within its invaded habitats. Manipulative experiments were used to test the response of benthic macroinvertebrates within two rivers that were differentially impacted by catfish as a presstype disturbance. Macroinvertebrates were non-responsive to catfish presence within a system where catfish had previously been established. In contrast, excluding catfish in this system indicated a response that suggested the importance of refuge within invaded habitats and the possible recovery pattern of certain macroinvertebrate taxa. By comparison, introduction of catfish within previously uninvaded localities provided evidence of direct catfish impact through elimination of conspicuous taxa. Acoustic telemetry was used to investigate catfish movement patterns within an invaded lentic habitat and provided evidence that habitat utilisation was non-random. The shallow and structured river mouth habitat, which was most utilised, was probably the most ideal for its breeding and feeding. This inferred potential overlap with native species and suggested the risk of predation and competitive interference. Catfish also exhibited both nocturnal and diurnal activity patterns that were probably related to feeding.
- Full Text:
- Date Issued: 2012
The feeding and spatial ecology of cheetahs (Acinonyx jubatus) and lions (Panthera leo) in the Little Karoo, South Africa
- Authors: Vorster, Paul Hendrik
- Date: 2012
- Subjects: Sanbona Wildlife Reserve , Cheetah -- South Africa -- Little Karoo , Lion -- South Africa -- Little Karoo , Cheetah -- Behavior -- South Africa -- Little Karoo , Lion -- Behavior -- South Africa -- Little Karoo , Cheetah -- Food -- South Africa -- Little Karoo , Lion -- Food -- South Africa -- Little Karoo , Spatial behavior in animals , Predation (Biology) , Game reserves -- Management
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5693 , http://hdl.handle.net/10962/d1005379 , Sanbona Wildlife Reserve , Cheetah -- South Africa -- Little Karoo , Lion -- South Africa -- Little Karoo , Cheetah -- Behavior -- South Africa -- Little Karoo , Lion -- Behavior -- South Africa -- Little Karoo , Cheetah -- Food -- South Africa -- Little Karoo , Lion -- Food -- South Africa -- Little Karoo , Spatial behavior in animals , Predation (Biology) , Game reserves -- Management
- Description: The re-introduction of large carnivores into relatively small conservation areas that fall within the historic distribution range of the species is becoming an increasingly common occurrence. The success of such re-introductions depends very much on the quality of the information that is available to guide management decisions, but in many cases, little information is available. The re-introduction of lions and cheetahs to Sanbona created the opportunity to monitor the behaviour of re-introduced predators to a relatively large system that was characterised by a low ungulate stocking density and little standing water. The broad aims were to study the feeding and spatial ecologies of the lions and cheetahs, to collect standard base-line data, and to examine the effects of the low prey density and limited standing water on habitat selection, range size and diet. The diet (data collected from direct observation and faecal analysis) was similar to that reported in previous studies, and lions and cheetahs preferred greater kudu, black wildebeest and springbok. Lions preferred medium to large prey items, and cheetahs preferred medium to small prey items. The hilly and mountainous terrain of much of the reserve meant that only 50% of the total space was available to the predators. Home ranges of most of the predators were focused around the single large body of standing water. This is likely to have been a response to the water, the vegetation, and the prey that was attracted to these. Habitat selection was also influenced by inter and intra-specific interactions at least for a solitary male lion and female cheetahs. Range sizes were larger than on some other reserves and it is suggested that this was a result of the low prey density. These results form the basis for management recommendations including the importance of continuing to monitor the system and opening up additional parts of the reserve to the predators.
- Full Text:
- Date Issued: 2012
- Authors: Vorster, Paul Hendrik
- Date: 2012
- Subjects: Sanbona Wildlife Reserve , Cheetah -- South Africa -- Little Karoo , Lion -- South Africa -- Little Karoo , Cheetah -- Behavior -- South Africa -- Little Karoo , Lion -- Behavior -- South Africa -- Little Karoo , Cheetah -- Food -- South Africa -- Little Karoo , Lion -- Food -- South Africa -- Little Karoo , Spatial behavior in animals , Predation (Biology) , Game reserves -- Management
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5693 , http://hdl.handle.net/10962/d1005379 , Sanbona Wildlife Reserve , Cheetah -- South Africa -- Little Karoo , Lion -- South Africa -- Little Karoo , Cheetah -- Behavior -- South Africa -- Little Karoo , Lion -- Behavior -- South Africa -- Little Karoo , Cheetah -- Food -- South Africa -- Little Karoo , Lion -- Food -- South Africa -- Little Karoo , Spatial behavior in animals , Predation (Biology) , Game reserves -- Management
- Description: The re-introduction of large carnivores into relatively small conservation areas that fall within the historic distribution range of the species is becoming an increasingly common occurrence. The success of such re-introductions depends very much on the quality of the information that is available to guide management decisions, but in many cases, little information is available. The re-introduction of lions and cheetahs to Sanbona created the opportunity to monitor the behaviour of re-introduced predators to a relatively large system that was characterised by a low ungulate stocking density and little standing water. The broad aims were to study the feeding and spatial ecologies of the lions and cheetahs, to collect standard base-line data, and to examine the effects of the low prey density and limited standing water on habitat selection, range size and diet. The diet (data collected from direct observation and faecal analysis) was similar to that reported in previous studies, and lions and cheetahs preferred greater kudu, black wildebeest and springbok. Lions preferred medium to large prey items, and cheetahs preferred medium to small prey items. The hilly and mountainous terrain of much of the reserve meant that only 50% of the total space was available to the predators. Home ranges of most of the predators were focused around the single large body of standing water. This is likely to have been a response to the water, the vegetation, and the prey that was attracted to these. Habitat selection was also influenced by inter and intra-specific interactions at least for a solitary male lion and female cheetahs. Range sizes were larger than on some other reserves and it is suggested that this was a result of the low prey density. These results form the basis for management recommendations including the importance of continuing to monitor the system and opening up additional parts of the reserve to the predators.
- Full Text:
- Date Issued: 2012
Environmental factors influencing learner absenteeism in six schools in the Kavango Region, Namibia
- Authors: Sanzila, Keith Mumba
- Date: 2012
- Subjects: School attendance -- Namibia -- Kavango Education -- Namibia -- Kavango Education and state -- Namibia -- Kavango Education -- Social aspects -- Namibia -- Kavango High school students -- Namibia -- Kavango -- Attitudes High school students -- Namibia -- Kavango -- Social conditions
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1516 , http://hdl.handle.net/10962/d1003398
- Description: This study on learner absenteeism takes place in the Namibian context with a focus on the Kavango region, located in Northern Namibia, where absenteeism has been identified as a problem. The intention of the study is to find out the relationship between learner absenteeism and environmental factors. The research question was framed as: How do environmental factors influence learner absenteeism in schools, conceptualised as human activity systems in the Kavango Region (Namibia)? The wider intention of this study is to inform processes that can be put in place to reduce the impact of environmental factors on learner absenteeism, with the ultimate view of improving the quality of education. The literature review provides insight into learner absenteeism in developing and developed nations. It outlines the Namibian policies developed for improving learner attendance and retention of learners in schools, with the view of improving access to school. The study is located within the broader goals of education of Namibia. The research adopts a qualitative interpretive approach, and focuses on environmental factors influencing learner absenteeism in six case studies, which are selected schools in the Kavango province. The study uses a variety of tools such as questionnaires, focus group interviews, observations and interviews as well as document analysis. It uses a combination of inductive and abductive modes of inference in the data analysis. It draws on systems thinking to develop a model that theorises the interrelated roles of different stakeholders, namely, learners, teachers, parents, educational officials (including the regional office and the Ministry of Education). It proposes possible strategies for reduction of learner absenteeism that could contribute towards the improvement of the quality of education. It also mentions the benefits of reducing learner absenteeism in the schools involved in the case study. The findings clearly show that poverty is the main environmental factor that influences learner attendance. The impact of poverty does not, however, occur in isolation; it interacts and has influence over other environmental factors such as alcohol abuse, sickness, lack of parental involvement, lack of motivation from stakeholders and household work. The study also found certain educational factors influenced learner absenteeism, such as teacher attitude, pedagogical styles, and lack of security. The study ends with recommendations to reduce learner absenteeism and recommendations for further research.
- Full Text:
- Date Issued: 2012
- Authors: Sanzila, Keith Mumba
- Date: 2012
- Subjects: School attendance -- Namibia -- Kavango Education -- Namibia -- Kavango Education and state -- Namibia -- Kavango Education -- Social aspects -- Namibia -- Kavango High school students -- Namibia -- Kavango -- Attitudes High school students -- Namibia -- Kavango -- Social conditions
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1516 , http://hdl.handle.net/10962/d1003398
- Description: This study on learner absenteeism takes place in the Namibian context with a focus on the Kavango region, located in Northern Namibia, where absenteeism has been identified as a problem. The intention of the study is to find out the relationship between learner absenteeism and environmental factors. The research question was framed as: How do environmental factors influence learner absenteeism in schools, conceptualised as human activity systems in the Kavango Region (Namibia)? The wider intention of this study is to inform processes that can be put in place to reduce the impact of environmental factors on learner absenteeism, with the ultimate view of improving the quality of education. The literature review provides insight into learner absenteeism in developing and developed nations. It outlines the Namibian policies developed for improving learner attendance and retention of learners in schools, with the view of improving access to school. The study is located within the broader goals of education of Namibia. The research adopts a qualitative interpretive approach, and focuses on environmental factors influencing learner absenteeism in six case studies, which are selected schools in the Kavango province. The study uses a variety of tools such as questionnaires, focus group interviews, observations and interviews as well as document analysis. It uses a combination of inductive and abductive modes of inference in the data analysis. It draws on systems thinking to develop a model that theorises the interrelated roles of different stakeholders, namely, learners, teachers, parents, educational officials (including the regional office and the Ministry of Education). It proposes possible strategies for reduction of learner absenteeism that could contribute towards the improvement of the quality of education. It also mentions the benefits of reducing learner absenteeism in the schools involved in the case study. The findings clearly show that poverty is the main environmental factor that influences learner attendance. The impact of poverty does not, however, occur in isolation; it interacts and has influence over other environmental factors such as alcohol abuse, sickness, lack of parental involvement, lack of motivation from stakeholders and household work. The study also found certain educational factors influenced learner absenteeism, such as teacher attitude, pedagogical styles, and lack of security. The study ends with recommendations to reduce learner absenteeism and recommendations for further research.
- Full Text:
- Date Issued: 2012
Touching Brýnstone
- Authors: Woudstra, Ruth
- Date: 2012
- Subjects: South African fiction (English) -- 21st century , Short stories, South African (English) -- 21st century , South African poetry (English) -- 21st century , Creative writing (Higher education) , Diaries -- Authorship , English language -- Writing
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2504 , http://hdl.handle.net/10962/d1015032
- Description: Touching Brýnstone is the story of Beth, a young journalist who is troubled by misfortunes in her family and work circumstances. In a Pretoria library she is seduced by a book that consoles her and progressively becomes a fetish object. It sparks a journey to Japan, where she arrives to teach English. She is intent on meeting the author, whom she confounds with protagonist and book. This Bildungsroman is an exploration of the complex relationship between inner and outer self, and the struggle towards wholeness. Beth must find a way out of the obsession so that she can return to South Africa with an enriched insight into her shadow self.
- Full Text:
- Date Issued: 2012
- Authors: Woudstra, Ruth
- Date: 2012
- Subjects: South African fiction (English) -- 21st century , Short stories, South African (English) -- 21st century , South African poetry (English) -- 21st century , Creative writing (Higher education) , Diaries -- Authorship , English language -- Writing
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2504 , http://hdl.handle.net/10962/d1015032
- Description: Touching Brýnstone is the story of Beth, a young journalist who is troubled by misfortunes in her family and work circumstances. In a Pretoria library she is seduced by a book that consoles her and progressively becomes a fetish object. It sparks a journey to Japan, where she arrives to teach English. She is intent on meeting the author, whom she confounds with protagonist and book. This Bildungsroman is an exploration of the complex relationship between inner and outer self, and the struggle towards wholeness. Beth must find a way out of the obsession so that she can return to South Africa with an enriched insight into her shadow self.
- Full Text:
- Date Issued: 2012
An analysis of the financing mechanisms proposed for funding national health insurance in South Africa
- Authors: Stevens, Nicol Susan
- Date: 2012
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:888 , http://hdl.handle.net/10962/d1001642
- Description: In the 2011 Budget Speech, the Minister of Finance announced that South Africa would be introducing National Health Insurance. The Minister described the financing mechanisms under consideration for funding National Health Insurance. The Minister also referred to eight countries, namely Japan, South Korea, Taiwan, Chile, Colombia, Mexico, Thailand and Vietnam as examples of countries which had successfully implemented universal health coverage. These countries were selected for the purpose of the present research. The goal of this study was to analyse the health care financing mechanisms under consideration in South Africa to determine if they were in line with international trends and "best practice" in relation to South Africa's economic profile. To determine whether the economic situation in South Africa is comparable to the eight countries selected for the research, a high-level comparison was made of the economic profile of South Africa and the eight countries, based on certain demographic, macro-economic, health expenditure and health status indicators. The health care financing mechanisms used in the eight countries was also analysed. International trends suggested that health care should be financed primarily through pre-payment systems, that financing mechanisms should preferably be progressive in nature and that a large share of funding should be from government sources (albeit shared between general tax revenue and specific health care contributions). The financing mechanisms under consideration in South Africa reflect these norms. The health systems in the eight countries analysed all exhibited elements of "good performance" and also complied, to a large extent, with international trends, but the frnancing models used for funding health care in the eight countries were country-specific and could therefore not be compared directly or used to recommend a system for South Africa. Areas not addressed by this thesis include the implications of a centralised healthcare system, the implications of a single-payer system, the benefit package to be offered and its cost implications, the role of private healthcare providers and how the significant human resource scarcity and infrastructure backlogs will be addressed.
- Full Text:
- Date Issued: 2012
- Authors: Stevens, Nicol Susan
- Date: 2012
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:888 , http://hdl.handle.net/10962/d1001642
- Description: In the 2011 Budget Speech, the Minister of Finance announced that South Africa would be introducing National Health Insurance. The Minister described the financing mechanisms under consideration for funding National Health Insurance. The Minister also referred to eight countries, namely Japan, South Korea, Taiwan, Chile, Colombia, Mexico, Thailand and Vietnam as examples of countries which had successfully implemented universal health coverage. These countries were selected for the purpose of the present research. The goal of this study was to analyse the health care financing mechanisms under consideration in South Africa to determine if they were in line with international trends and "best practice" in relation to South Africa's economic profile. To determine whether the economic situation in South Africa is comparable to the eight countries selected for the research, a high-level comparison was made of the economic profile of South Africa and the eight countries, based on certain demographic, macro-economic, health expenditure and health status indicators. The health care financing mechanisms used in the eight countries was also analysed. International trends suggested that health care should be financed primarily through pre-payment systems, that financing mechanisms should preferably be progressive in nature and that a large share of funding should be from government sources (albeit shared between general tax revenue and specific health care contributions). The financing mechanisms under consideration in South Africa reflect these norms. The health systems in the eight countries analysed all exhibited elements of "good performance" and also complied, to a large extent, with international trends, but the frnancing models used for funding health care in the eight countries were country-specific and could therefore not be compared directly or used to recommend a system for South Africa. Areas not addressed by this thesis include the implications of a centralised healthcare system, the implications of a single-payer system, the benefit package to be offered and its cost implications, the role of private healthcare providers and how the significant human resource scarcity and infrastructure backlogs will be addressed.
- Full Text:
- Date Issued: 2012
Ties that bind
- Authors: Tshisela, Namhla
- Date: 2012
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:20988 , http://hdl.handle.net/10962/5913
- Description: This collection of short stories about contemporary black South African women reveals their hopes and anxieties, and explores their relationships with themselves, their families, and the people around them. It sets out to challenge stereotypes about black women being browbeaten in a country riddled by poverty and disease by portraying women successfully forging their identities in society.
- Full Text:
- Date Issued: 2012
- Authors: Tshisela, Namhla
- Date: 2012
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:20988 , http://hdl.handle.net/10962/5913
- Description: This collection of short stories about contemporary black South African women reveals their hopes and anxieties, and explores their relationships with themselves, their families, and the people around them. It sets out to challenge stereotypes about black women being browbeaten in a country riddled by poverty and disease by portraying women successfully forging their identities in society.
- Full Text:
- Date Issued: 2012
Narrating emergence in the curious terrain of academic development research: a realist perspective
- Authors: Niven, Penelope Mary
- Date: 2012
- Subjects: Education, Higher -- Aims and objectives -- South Africa Universities and colleges -- South Africa Educational change -- South Africa Black people -- Education (Higher) -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1675 , http://hdl.handle.net/10962/d1003558
- Description: This dissertation adopts a realist meta-perspective on a body of the scholar's own research papers written between 2005 and 2011, all either published or in press and offered for reference in the Appendices. The six papers represent the point of departure for the thesis; they are the phenomenon for further investigation into 'what must be the case' for the research events to have emerged as they did. One aspect of this study, therefore, is an auto ethnographic account of conducting research in the field of Academic Development within varied settings and over a given time frame. But alongside this personal history it narrates cycles in the Academic Development movement in South Africa over 30 years. Margaret Archer's Social Realist principle of analytical dualism (1995) is used to disaggregate the emergent properties within these histories and to enable an analysis of the underlying mechanisms that generated them. It refers to three social domains. Firstly, it describes the material structures - the institutional environments, policies, roles or professional conditions - in which the projects were conceived. Secondly, it identifies the cultural registers that the profession was drawing on - such as theories, beliefs or discourses. Thirdly, it draws attention to the agency of individuals and communities in the field as they independently activated or mediated these various conditioning structures and registers. So the study is a systematic examination of the parts and the people in research stories, of the complex interrelationship of structural and agential elements, and of how together they have generated particular forms of knowing and kinds of knowledge in Academic Development. Drawing from this 'history-within-a-history', the study makes some claims for 'what must be the case' for substantial knowledge to flourish in a newly emergent, hotly contested and relatively unstable field. It argues that Academic Development has few shared epistemological foundations and boundaries, and its roles and functions are shifting and diverse. It describes the tensions in the field between those who have been inclined to understand it as primarily concerned with redress or equity in the postapartheid state, and yet others who have prioritised Academic Development as an efficiency project within higher education. But there is a third discourse emanating from those in the profession who have consistently argued that neither of these approaches can succeed without drawing on stronger theoretical foundations. This study endorses the view that Academic Developers need to identify more coherent ontological and epistemological frames for their research work. This has important implications for building the kind of substantial knowledge base that could be more influential in addressing the troubled terrain of South African higher education. The study refers extensively to Lewis Carroll's Alice in Wonderland (1865) and Through the Looking-Glass (1871) and to Mervyn Peake's 1946 illustrations of these children's stories, finding in these texts powerful analogies and metaphors for principles in realist philosophy and theory, and for describing a researcher's journey towards a more assured identity in the curious field of Academic Development.
- Full Text:
- Date Issued: 2012
- Authors: Niven, Penelope Mary
- Date: 2012
- Subjects: Education, Higher -- Aims and objectives -- South Africa Universities and colleges -- South Africa Educational change -- South Africa Black people -- Education (Higher) -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1675 , http://hdl.handle.net/10962/d1003558
- Description: This dissertation adopts a realist meta-perspective on a body of the scholar's own research papers written between 2005 and 2011, all either published or in press and offered for reference in the Appendices. The six papers represent the point of departure for the thesis; they are the phenomenon for further investigation into 'what must be the case' for the research events to have emerged as they did. One aspect of this study, therefore, is an auto ethnographic account of conducting research in the field of Academic Development within varied settings and over a given time frame. But alongside this personal history it narrates cycles in the Academic Development movement in South Africa over 30 years. Margaret Archer's Social Realist principle of analytical dualism (1995) is used to disaggregate the emergent properties within these histories and to enable an analysis of the underlying mechanisms that generated them. It refers to three social domains. Firstly, it describes the material structures - the institutional environments, policies, roles or professional conditions - in which the projects were conceived. Secondly, it identifies the cultural registers that the profession was drawing on - such as theories, beliefs or discourses. Thirdly, it draws attention to the agency of individuals and communities in the field as they independently activated or mediated these various conditioning structures and registers. So the study is a systematic examination of the parts and the people in research stories, of the complex interrelationship of structural and agential elements, and of how together they have generated particular forms of knowing and kinds of knowledge in Academic Development. Drawing from this 'history-within-a-history', the study makes some claims for 'what must be the case' for substantial knowledge to flourish in a newly emergent, hotly contested and relatively unstable field. It argues that Academic Development has few shared epistemological foundations and boundaries, and its roles and functions are shifting and diverse. It describes the tensions in the field between those who have been inclined to understand it as primarily concerned with redress or equity in the postapartheid state, and yet others who have prioritised Academic Development as an efficiency project within higher education. But there is a third discourse emanating from those in the profession who have consistently argued that neither of these approaches can succeed without drawing on stronger theoretical foundations. This study endorses the view that Academic Developers need to identify more coherent ontological and epistemological frames for their research work. This has important implications for building the kind of substantial knowledge base that could be more influential in addressing the troubled terrain of South African higher education. The study refers extensively to Lewis Carroll's Alice in Wonderland (1865) and Through the Looking-Glass (1871) and to Mervyn Peake's 1946 illustrations of these children's stories, finding in these texts powerful analogies and metaphors for principles in realist philosophy and theory, and for describing a researcher's journey towards a more assured identity in the curious field of Academic Development.
- Full Text:
- Date Issued: 2012
International passports : portrait of the Nigerian diaspora
- Authors: Makun, Adetoun Jones
- Date: 2012
- Subjects: Portrait painting -- South Africa Nigerians -- Portraits Portrait photography -- Nigeria
- Language: English
- Type: Thesis , Masters , MFA
- Identifier: vital:2429 , http://hdl.handle.net/10962/d1002226
- Description: International Passports: Portraits of the Nigerian Diaspora considers notions of 'alienation‘ and 'nation-hood‘ through the lens of portraiture. This dissertation addresses issues of identity and representation in a contemporary cultural context as they pertain to the concerns presented through my current visual practice. The paintings that I have produced from 'real‘ life are primarily depictions of Nigerian individuals, friends and acquaintances (professionals and students) residing in Grahamstown, South Africa as temporary or permanent migrants. I reference the mug shot pose of identity documents and passport photographs and render them in such a way that ideas of their persona are subject to the viewer‘s gaze and deliberations, thus provoking the spectator to consider questions of 'otherness‘ and 'stereotypes‘. This provocation is subtle and complex, and in many ways I am offering the viewer a 're-looking‘, an opportunity to examine one‘s moral position and subsequent implication within the act of stereotyping an 'other‘ individual. The initial idea within this body of work was to paint images of Nigerian nationals exclusively, yet the restrictive nature of such categorization pushed me to complicate certain nationalist ideologies through the inclusion of non-Nigerian individuals. I look specifically at notions of the 'other‘ and 'strangeness‘ in a contemporary South African context and how this connects to the concept of portraiture and not simply portraiture theory but also the social theory in relation to how people are 'imaged‘. Throughout this thesis I consider several theoretical concerns in portraiture practice and discourse whilst simultaneously unpacking the psychological and social contexts that influence my practice.
- Full Text:
- Date Issued: 2012
- Authors: Makun, Adetoun Jones
- Date: 2012
- Subjects: Portrait painting -- South Africa Nigerians -- Portraits Portrait photography -- Nigeria
- Language: English
- Type: Thesis , Masters , MFA
- Identifier: vital:2429 , http://hdl.handle.net/10962/d1002226
- Description: International Passports: Portraits of the Nigerian Diaspora considers notions of 'alienation‘ and 'nation-hood‘ through the lens of portraiture. This dissertation addresses issues of identity and representation in a contemporary cultural context as they pertain to the concerns presented through my current visual practice. The paintings that I have produced from 'real‘ life are primarily depictions of Nigerian individuals, friends and acquaintances (professionals and students) residing in Grahamstown, South Africa as temporary or permanent migrants. I reference the mug shot pose of identity documents and passport photographs and render them in such a way that ideas of their persona are subject to the viewer‘s gaze and deliberations, thus provoking the spectator to consider questions of 'otherness‘ and 'stereotypes‘. This provocation is subtle and complex, and in many ways I am offering the viewer a 're-looking‘, an opportunity to examine one‘s moral position and subsequent implication within the act of stereotyping an 'other‘ individual. The initial idea within this body of work was to paint images of Nigerian nationals exclusively, yet the restrictive nature of such categorization pushed me to complicate certain nationalist ideologies through the inclusion of non-Nigerian individuals. I look specifically at notions of the 'other‘ and 'strangeness‘ in a contemporary South African context and how this connects to the concept of portraiture and not simply portraiture theory but also the social theory in relation to how people are 'imaged‘. Throughout this thesis I consider several theoretical concerns in portraiture practice and discourse whilst simultaneously unpacking the psychological and social contexts that influence my practice.
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- Date Issued: 2012