The national health insurance bill: a measure to realise the right to access health care services
- Authors: Moyo, Priscilla Tariro
- Date: 2020
- Subjects: Medical laws and legislation -- South Africa , Health insurance -- South Africa
- Language: English
- Type: Thesis , Masters , LLM
- Identifier: http://hdl.handle.net/10948/49016 , vital:41593
- Description: The right to access health care services is enshrined in section 27 of the Constitution. It is a right afforded to everyone. The state is required to adopt legislative and other measures for the progressive realisation of this right. To that effect, the state has passed various pieces of legislation aimed at realising the right to access health care services. The key legislative measures regulating the health system are the National Health Act, the Medical Schemes Act and the Medicines Act. Despite the various legislative measures in place, not everyone has access to health care services and there is a need for reform in the health system. To remedy the problem of inaccessibility, the government introduced the NHI Bill in 2018 which was amended in 2019. The NHI Bill purports to amend the way in which health services are financed. The purpose of this research is to determine the constitutionality of selected aspects of the NHI Bill. Section 27(2) of the Constitution requires that any measure adopted by the state in realising the right to access health care services must be reasonable. This research, therefore, assesses whether the NHI Bill is a reasonable measure that meets the requirements of section 27(2). The NHI Bill will be assessed in light of the reasonableness review used to assess state compliance with the obligation in terms of section 27. In assessing the reasonableness of the NHI Bill, reference is made to the domestic obligations of the state to realise the right to access health care services, the context in which the NHI Bill was published, the provisions of international law, and the impact the NHI Bill will have on other rights specifically the right to equality. The findings of this research are that the NHI Bill is likely to be found unconstitutional insofar as it unfairly discriminates against asylum seekers and undocumented migrants and lacks clarity with respect to important issues such as the role of medical schemes. Based on this analysis, recommendations are made to ensure that the NHI Bill is constitutionally sound.
- Full Text:
- Date Issued: 2020
- Authors: Moyo, Priscilla Tariro
- Date: 2020
- Subjects: Medical laws and legislation -- South Africa , Health insurance -- South Africa
- Language: English
- Type: Thesis , Masters , LLM
- Identifier: http://hdl.handle.net/10948/49016 , vital:41593
- Description: The right to access health care services is enshrined in section 27 of the Constitution. It is a right afforded to everyone. The state is required to adopt legislative and other measures for the progressive realisation of this right. To that effect, the state has passed various pieces of legislation aimed at realising the right to access health care services. The key legislative measures regulating the health system are the National Health Act, the Medical Schemes Act and the Medicines Act. Despite the various legislative measures in place, not everyone has access to health care services and there is a need for reform in the health system. To remedy the problem of inaccessibility, the government introduced the NHI Bill in 2018 which was amended in 2019. The NHI Bill purports to amend the way in which health services are financed. The purpose of this research is to determine the constitutionality of selected aspects of the NHI Bill. Section 27(2) of the Constitution requires that any measure adopted by the state in realising the right to access health care services must be reasonable. This research, therefore, assesses whether the NHI Bill is a reasonable measure that meets the requirements of section 27(2). The NHI Bill will be assessed in light of the reasonableness review used to assess state compliance with the obligation in terms of section 27. In assessing the reasonableness of the NHI Bill, reference is made to the domestic obligations of the state to realise the right to access health care services, the context in which the NHI Bill was published, the provisions of international law, and the impact the NHI Bill will have on other rights specifically the right to equality. The findings of this research are that the NHI Bill is likely to be found unconstitutional insofar as it unfairly discriminates against asylum seekers and undocumented migrants and lacks clarity with respect to important issues such as the role of medical schemes. Based on this analysis, recommendations are made to ensure that the NHI Bill is constitutionally sound.
- Full Text:
- Date Issued: 2020
Geological and geophysical assessment of groundwater vulnerability to contamination in selected general landfill sites in the Eastern Cape Province, South Africa
- Authors: Mepaiyeda, Seyi
- Date: 2019
- Subjects: Groundwater -- Pollution Sanitary landfills
- Language: English
- Type: Thesis , Doctoral , PhD (Geology)
- Identifier: http://hdl.handle.net/10353/12227 , vital:39217
- Description: Increasing expansion, population and urbanization have resulted in high volume of waste generated daily in South Africa. Most municipalities in the Eastern Cape are experiencing challenges in effective waste disposal, thus resulting in pollution of the air, soil and groundwater by the percolation of harmful contaminants into the environment from landfill leachate. Groundwater resources are limited in South Africa due to itssemi-arid nature. Also, there islimited information available, not only about where it occurs but how to manage it so that its quality does not depreciate to unacceptable levels. A combination of these factors coupled with a gap between waste policy and its subsequent implementation may be disastrous to South Africa. This research examines the impact of landfill sites on groundwater resources at three selected sites in the Eastern Cape Province using an integrated geological and geophysical approach. The methodology adopted include: an exhaustive literature review on waste management policies and practices in South Africa and Eastern Cape specifically. It also involved remote sensing for the study of geomorphology and structural interpretations of lineaments. Field excursions, analysis of physico-chemical and geochemical properties of groundwater obtained from monitoring boreholes and leachate pond in the vicinity of the landfill sites was also carried out. Combined induced polarization (IP) and electrical resistivity measurements for geophysical assessment of groundwater vulnerability and petrographical analysis was alos adopted. Data analysis and interpretation of the obtained results showed that the selected landfill sites are generally characterized by a 4-layer Earth structure with an average depth to top of the bedrock between 15 m - 30 m. Plant-rock association observed from the aerial photo-interpretation showed groundwater potential around the locality of the landfill sites with a dendritic to poorly drained x patterns and moderate to high topography. Structural controls such as the presence of lineaments and a fractured bedrock beneath, which are excellent pathways for the migration of leachate, particularly at the Berlin and King Williams Town landfill sites were observed. Analysis of physico-chemical and geochemical properties of water samples showed contamination of the groundwater by heavy metals and some of the physico-chemical properties were above the generally acceptable limits (WHO). These include high electrical conductivity (EC) and total dissolved solid (TDS) values observed in the groundwater samples from the King Williams Town landfill which indicated a downward transfer of leachate into the groundwater. The difference in EC and TDS values for boreholes BH2 and BH1 (9892 µS/cm, 4939 mg/L and 6988 µS/cm, 3497 mg/L respectively), showed that concentration of contaminants increased towards the centre of the landfill. Interpretation of the obtained results from the Berlin landfill showed the presence of heavy metals in groundwater samples in high concentrations. This indicated the dumping of toxic and hazardous waste substances on the landfill, contrary to the landfill design and classification. This could have harmful effect on plants and animals. Integrated geophysical assessment showed the presence of leachate plumes on pseudosections across the landfill sites. This was further corroborated on the chargeability pseudosections. Resistivity and IP pseudosections from the Berlin landfill showed a 4-layered Earth structure and anomalous zones of resistivity (≤ 112 Ώ-m) and low chargeability (≤1.25 ms) in the top layers. This is indicative of percolating leachate plume in the unsaturated zone. Contaminants ranging from unsaturated waste with high ion content to dense aqueous phase liquid contaminants, characterized by low resistivity (34 Ώm to 80 Ώ-m) and low chargeability values (0.05 ms to 5.75 ms) were identified across the Alice landfill. Results from the King Williams Town Landfill revealed plume contamination to a depth of about 75 m, well within the aquiferous zone. xi It is suggested that waste disposal practices should be improved by proper waste inspection and classification at landfills prior to disposal, use of lining and cap material to prevent leaching of contaminants into the groundwater below and the construction of waste cells and containment structures. This will go a long way in mitigating groundwater contamination due to landfilling at the study areas
- Full Text:
- Date Issued: 2019
- Authors: Mepaiyeda, Seyi
- Date: 2019
- Subjects: Groundwater -- Pollution Sanitary landfills
- Language: English
- Type: Thesis , Doctoral , PhD (Geology)
- Identifier: http://hdl.handle.net/10353/12227 , vital:39217
- Description: Increasing expansion, population and urbanization have resulted in high volume of waste generated daily in South Africa. Most municipalities in the Eastern Cape are experiencing challenges in effective waste disposal, thus resulting in pollution of the air, soil and groundwater by the percolation of harmful contaminants into the environment from landfill leachate. Groundwater resources are limited in South Africa due to itssemi-arid nature. Also, there islimited information available, not only about where it occurs but how to manage it so that its quality does not depreciate to unacceptable levels. A combination of these factors coupled with a gap between waste policy and its subsequent implementation may be disastrous to South Africa. This research examines the impact of landfill sites on groundwater resources at three selected sites in the Eastern Cape Province using an integrated geological and geophysical approach. The methodology adopted include: an exhaustive literature review on waste management policies and practices in South Africa and Eastern Cape specifically. It also involved remote sensing for the study of geomorphology and structural interpretations of lineaments. Field excursions, analysis of physico-chemical and geochemical properties of groundwater obtained from monitoring boreholes and leachate pond in the vicinity of the landfill sites was also carried out. Combined induced polarization (IP) and electrical resistivity measurements for geophysical assessment of groundwater vulnerability and petrographical analysis was alos adopted. Data analysis and interpretation of the obtained results showed that the selected landfill sites are generally characterized by a 4-layer Earth structure with an average depth to top of the bedrock between 15 m - 30 m. Plant-rock association observed from the aerial photo-interpretation showed groundwater potential around the locality of the landfill sites with a dendritic to poorly drained x patterns and moderate to high topography. Structural controls such as the presence of lineaments and a fractured bedrock beneath, which are excellent pathways for the migration of leachate, particularly at the Berlin and King Williams Town landfill sites were observed. Analysis of physico-chemical and geochemical properties of water samples showed contamination of the groundwater by heavy metals and some of the physico-chemical properties were above the generally acceptable limits (WHO). These include high electrical conductivity (EC) and total dissolved solid (TDS) values observed in the groundwater samples from the King Williams Town landfill which indicated a downward transfer of leachate into the groundwater. The difference in EC and TDS values for boreholes BH2 and BH1 (9892 µS/cm, 4939 mg/L and 6988 µS/cm, 3497 mg/L respectively), showed that concentration of contaminants increased towards the centre of the landfill. Interpretation of the obtained results from the Berlin landfill showed the presence of heavy metals in groundwater samples in high concentrations. This indicated the dumping of toxic and hazardous waste substances on the landfill, contrary to the landfill design and classification. This could have harmful effect on plants and animals. Integrated geophysical assessment showed the presence of leachate plumes on pseudosections across the landfill sites. This was further corroborated on the chargeability pseudosections. Resistivity and IP pseudosections from the Berlin landfill showed a 4-layered Earth structure and anomalous zones of resistivity (≤ 112 Ώ-m) and low chargeability (≤1.25 ms) in the top layers. This is indicative of percolating leachate plume in the unsaturated zone. Contaminants ranging from unsaturated waste with high ion content to dense aqueous phase liquid contaminants, characterized by low resistivity (34 Ώm to 80 Ώ-m) and low chargeability values (0.05 ms to 5.75 ms) were identified across the Alice landfill. Results from the King Williams Town Landfill revealed plume contamination to a depth of about 75 m, well within the aquiferous zone. xi It is suggested that waste disposal practices should be improved by proper waste inspection and classification at landfills prior to disposal, use of lining and cap material to prevent leaching of contaminants into the groundwater below and the construction of waste cells and containment structures. This will go a long way in mitigating groundwater contamination due to landfilling at the study areas
- Full Text:
- Date Issued: 2019
Hearing the citizens: inequality, access to journalists and the prospects for inclusively mediated spaces of political deliberation in South Africa
- Authors: Oelofsen, Marietjie
- Date: 2017
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/35030 , vital:24309
- Description: This study examines the extent to which material and social inequality in post-apartheid South Africa affect possibilities for poor citizens to gain access to mainstream spaces of mediated political deliberation. Access is problematized in terms of the possibilities that exist for poor citizens to ‘appear’ in these spaces as emancipated citizens with political agency. The study is motivated by a perception that South Africa’s middle-class and privileged citizens have more access to political deliberation because mainstream journalists pay more attention to their political concerns. Because mediated political deliberation provides a space for articulating the political will of citizens it is important that it reflects the multiple, and diverse range of voices that make up South Africa’s polity. If the experience of socioeconomically marginalised citizens is not registered in the same way as the experience of citizens with economic and political power, the balance of political decision-making continues to be skewed against the interests of the poor. Rather than a media-centric approach, the study centres on perceptions and views of poor citizens about their relationship with mainstream journalists. The study combines information from group interviews with citizens from Hangberg, Cape Town with 410 news reports in 18 mainstream newspapers about Hangberg citizens over a 20-year period. The interviews show that poor citizens feel largely excluded from mediated political deliberation; not because they do not appear in the news but because of how they appear in the news. The news reports confirm that mainstream journalists pay more attention to voices with political and economic power than to the voices of poor citizens. Even in news reports about Hangberg citizens, political leaders and non-governmental experts often talk about the problems in Hangberg more than the citizens of Hangberg themselves talk about these problems. Building on a relatively new scholarly interest in ‘active’ and ‘political’ listening in media studies and democratic theory (Bickford 1996, Dreher 2009, Couldry 2009, Dobson 2014, Wasserman 2013, Garman and Malila 2014), I consider listening as a constitutive element of the way in which journalists engage with poor citizens in mediated deliberative spaces. I ask whether different practices of listening can enable journalists to construct narratives that provide marginalised groups with different possibilities for equal access to, and participation in these spaces?
- Full Text:
- Date Issued: 2017
- Authors: Oelofsen, Marietjie
- Date: 2017
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/35030 , vital:24309
- Description: This study examines the extent to which material and social inequality in post-apartheid South Africa affect possibilities for poor citizens to gain access to mainstream spaces of mediated political deliberation. Access is problematized in terms of the possibilities that exist for poor citizens to ‘appear’ in these spaces as emancipated citizens with political agency. The study is motivated by a perception that South Africa’s middle-class and privileged citizens have more access to political deliberation because mainstream journalists pay more attention to their political concerns. Because mediated political deliberation provides a space for articulating the political will of citizens it is important that it reflects the multiple, and diverse range of voices that make up South Africa’s polity. If the experience of socioeconomically marginalised citizens is not registered in the same way as the experience of citizens with economic and political power, the balance of political decision-making continues to be skewed against the interests of the poor. Rather than a media-centric approach, the study centres on perceptions and views of poor citizens about their relationship with mainstream journalists. The study combines information from group interviews with citizens from Hangberg, Cape Town with 410 news reports in 18 mainstream newspapers about Hangberg citizens over a 20-year period. The interviews show that poor citizens feel largely excluded from mediated political deliberation; not because they do not appear in the news but because of how they appear in the news. The news reports confirm that mainstream journalists pay more attention to voices with political and economic power than to the voices of poor citizens. Even in news reports about Hangberg citizens, political leaders and non-governmental experts often talk about the problems in Hangberg more than the citizens of Hangberg themselves talk about these problems. Building on a relatively new scholarly interest in ‘active’ and ‘political’ listening in media studies and democratic theory (Bickford 1996, Dreher 2009, Couldry 2009, Dobson 2014, Wasserman 2013, Garman and Malila 2014), I consider listening as a constitutive element of the way in which journalists engage with poor citizens in mediated deliberative spaces. I ask whether different practices of listening can enable journalists to construct narratives that provide marginalised groups with different possibilities for equal access to, and participation in these spaces?
- Full Text:
- Date Issued: 2017
Litter quality effects on soil stabiltiy and erodibility in the Ntabelanga Area, Eastern Cape, South Africa
- Authors: Parwada, Cosmas
- Date: 2017
- Subjects: Soil erosion Soil management -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/4824 , vital:28531
- Description: Soil organic matter (SOM) plays a primary role in aggregation and stabilization of soils, hence reducing their susceptibility to erosion. In South Africa (SA), most soils have low (< 4 percent) soil organic matte (SOM) contents, making them susceptible to soil erosion. Little is known about SOM quality effects in soil stabilization in the SA context, it is therefore difficult to advocate specific organic matter sources in order to stabilize a particular soil. This study evaluated effects of different litter quality sources (Vachellia karoo (sweet thorn) leaf litter and Zea mays (maize) stover) on soil aggregate stabilization at a soil micro-level (soil aggregate), guided by the following specific objectives; (i) to characterize soil properties that influence the erodibility of soils in the Ntabelanga area, Eastern Cape (EC) Province, SA (ii) to assess fractionation of organic carbon during decomposition of different litter sources (iii) to determine rate of soil macroaggregate re-formation under different litter amendments (iv) to determine the influence of different litter quality on splash soil erosion and (v) to delineate the Ntabelanga area into different soil erosion sensitivity zones. Soil samples collected from a proposed Ntabelanga dam site, EC Province, SA, were characterized for factors influencing erodibility. Soil physical and chemical properties were analyzed, soil erodibility (K-factor) estimated using SOC content and surface properties and soil loss rates by splashing determined under rainfall simulations at 360 mm h-1 rainfall intensity. Soil loss was then correlated with the chemical and physical soil properties. SOC showed significant (P< 0.05) inverse relationship with soil loss. Soils samples were bulked to seven composite samples according to major soil horizons (orthic A, melanic A, pedocutanic B, red apedal B, saprolite, G horizon and prismacutanic B) in the areas of soil associations, macroaggregate (> 0.250 mm) were removed by passing through a 0.250 mm sieve. The remaining soil microaggregates (< 0.250 mm) were then mixed with high quality Vachellia karoo leaf litter (C/N = 23.8) and low quality Zea mays stover (C/N = 37.4) and incubated at 23oC for 30 weeks. Jars were arranged as a 7 × 3 factorial laid in completely randomized design (CRD) with three replicates. Data was repeatedly measured at 1, 3, 8, 14, 23 and 30 weeks after incubation: to determine the stabilization of SOM by fractionating the soil particulate organic matter (POM), rate of soil macroaggregate re-formation and influence of litter quality on splash soil erosion along a decomposition continuum. Free light fractions (Free LF), coarse particulate organic matter (CoPOM) and fine particulate organic matter (FiPOM) within macroaggregates (> 250 μm) decreased exponentially from week 1 to 30 and were significantly (p < 0.05) influenced by litter quality × soil horizon × time interactions. A similar trend for FiPOM fractions in macroaggregates was observed in the 53-250 μm microaggregates (p < 0.05). The greatest influence on changes in POM fractions occurred within the first 3 weeks of incorporation. Both V. karroo leaf litter and Z. mays stover significantly stabilized the macroaggregates within the first 3 weeks after incubation. Cumulative macroaggregates yields, mean weight diameter (MWD), percentage water stable aggregates (%WSA) and whole soil stability index (WSSI) in litter amended soils increased up to week 8 of incubation and thereafter gradually declined in all soils. An increase in macroaggregation resulted in increased MWD, WSSI values and large and small aggregates distribution. Aggregation was significantly higher in soils with higher clay content than sand content, suggesting that soil texture was highly influential in litter decomposition. Rate of litter decomposition was influenced by soil type × time interactions which determined extent and macroaggregation dynamics along a decomposition continuum. The amount of splashed sediments was determined from each soil horizon at 360 mm h-1 simulated rainfall intensity applied as either single 8minute rainstorm (SR) or 4 × 2minute intermittent rainstorms (IR) separated by a 72 h drying period. Results showed a reduction in splashed sediments under IR and SR storms in litter-amended soils during the first 8 weeks of incubation with gradual increase thereafter. More sediments were splashed under IR than SR and litter quality had no influence on splashed sediments per soil horizon. Soil horizons profile with more clay than sand particles enhanced the litter effects on the soil resistance against detachment. The amount of SOC loss was influenced by primary particle size distribution and initial SOC content of the soil. Rainfall pattern and the initial SOC content were the main factors by which different soils influenced SOC loss. More rainstorm patterns should be investigated on these soils.
- Full Text:
- Date Issued: 2017
- Authors: Parwada, Cosmas
- Date: 2017
- Subjects: Soil erosion Soil management -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/4824 , vital:28531
- Description: Soil organic matter (SOM) plays a primary role in aggregation and stabilization of soils, hence reducing their susceptibility to erosion. In South Africa (SA), most soils have low (< 4 percent) soil organic matte (SOM) contents, making them susceptible to soil erosion. Little is known about SOM quality effects in soil stabilization in the SA context, it is therefore difficult to advocate specific organic matter sources in order to stabilize a particular soil. This study evaluated effects of different litter quality sources (Vachellia karoo (sweet thorn) leaf litter and Zea mays (maize) stover) on soil aggregate stabilization at a soil micro-level (soil aggregate), guided by the following specific objectives; (i) to characterize soil properties that influence the erodibility of soils in the Ntabelanga area, Eastern Cape (EC) Province, SA (ii) to assess fractionation of organic carbon during decomposition of different litter sources (iii) to determine rate of soil macroaggregate re-formation under different litter amendments (iv) to determine the influence of different litter quality on splash soil erosion and (v) to delineate the Ntabelanga area into different soil erosion sensitivity zones. Soil samples collected from a proposed Ntabelanga dam site, EC Province, SA, were characterized for factors influencing erodibility. Soil physical and chemical properties were analyzed, soil erodibility (K-factor) estimated using SOC content and surface properties and soil loss rates by splashing determined under rainfall simulations at 360 mm h-1 rainfall intensity. Soil loss was then correlated with the chemical and physical soil properties. SOC showed significant (P< 0.05) inverse relationship with soil loss. Soils samples were bulked to seven composite samples according to major soil horizons (orthic A, melanic A, pedocutanic B, red apedal B, saprolite, G horizon and prismacutanic B) in the areas of soil associations, macroaggregate (> 0.250 mm) were removed by passing through a 0.250 mm sieve. The remaining soil microaggregates (< 0.250 mm) were then mixed with high quality Vachellia karoo leaf litter (C/N = 23.8) and low quality Zea mays stover (C/N = 37.4) and incubated at 23oC for 30 weeks. Jars were arranged as a 7 × 3 factorial laid in completely randomized design (CRD) with three replicates. Data was repeatedly measured at 1, 3, 8, 14, 23 and 30 weeks after incubation: to determine the stabilization of SOM by fractionating the soil particulate organic matter (POM), rate of soil macroaggregate re-formation and influence of litter quality on splash soil erosion along a decomposition continuum. Free light fractions (Free LF), coarse particulate organic matter (CoPOM) and fine particulate organic matter (FiPOM) within macroaggregates (> 250 μm) decreased exponentially from week 1 to 30 and were significantly (p < 0.05) influenced by litter quality × soil horizon × time interactions. A similar trend for FiPOM fractions in macroaggregates was observed in the 53-250 μm microaggregates (p < 0.05). The greatest influence on changes in POM fractions occurred within the first 3 weeks of incorporation. Both V. karroo leaf litter and Z. mays stover significantly stabilized the macroaggregates within the first 3 weeks after incubation. Cumulative macroaggregates yields, mean weight diameter (MWD), percentage water stable aggregates (%WSA) and whole soil stability index (WSSI) in litter amended soils increased up to week 8 of incubation and thereafter gradually declined in all soils. An increase in macroaggregation resulted in increased MWD, WSSI values and large and small aggregates distribution. Aggregation was significantly higher in soils with higher clay content than sand content, suggesting that soil texture was highly influential in litter decomposition. Rate of litter decomposition was influenced by soil type × time interactions which determined extent and macroaggregation dynamics along a decomposition continuum. The amount of splashed sediments was determined from each soil horizon at 360 mm h-1 simulated rainfall intensity applied as either single 8minute rainstorm (SR) or 4 × 2minute intermittent rainstorms (IR) separated by a 72 h drying period. Results showed a reduction in splashed sediments under IR and SR storms in litter-amended soils during the first 8 weeks of incubation with gradual increase thereafter. More sediments were splashed under IR than SR and litter quality had no influence on splashed sediments per soil horizon. Soil horizons profile with more clay than sand particles enhanced the litter effects on the soil resistance against detachment. The amount of SOC loss was influenced by primary particle size distribution and initial SOC content of the soil. Rainfall pattern and the initial SOC content were the main factors by which different soils influenced SOC loss. More rainstorm patterns should be investigated on these soils.
- Full Text:
- Date Issued: 2017
Population, communication and habitat comparisons between the major gummivorous strepsirhines of Madagascar (phaner) and Cameroon (euoticus)
- Authors: Forbanka, Derick Nomuh
- Date: 2016
- Subjects: Adaptation (Biology) , Mammals -- Evolution , Mammals -- Behavior
- Language: English
- Type: Thesis , Doctoral , Zoology
- Identifier: http://hdl.handle.net/10353/15957 , vital:40567
- Description: The suborder Strepsirhini contains a large proportion of the living gummivorous mammal taxa, and includes two genera of specialist gummivores, Euoticus and Phaner, which present particularly interesting cases of convergent adaptive evolution in Africa and Madagascar, respectively. Although these genera are not closely related, they share several anatomical, behavioural and physiological specialisations associated with their diets, and despite their biogeographical separation, there seems to be substantial coincidence in their habitats and habits. Neither the ecology nor the systematics of Phaner and Euoticus has been the subject of much detailed research, and little is known of the conservation status of the genera. Even their specific diversity is unresolved. In this study I investigated and compared aspects of their ecology at both a macro-and a microhabitat scale, including wild populations of all groups within the two genera that have been accorded species status in recent field guides and systematic reviews. I also studied aspects of their social communication behaviour as clues to their species-level diversity. Species and their formation (or speciation) have inspired a great deal of evolutionary research, but remain contentious issues in evolutionary biology. This is due both to the difficulties inherent in inferring the details of a dynamic biological process that occurred over some time in the past from the recent, relatively static patterns of variation observed, as well as the limited consensus among biologists in identifying such patterns. It is therefore important to distinguish the kinds of patterns in nature that are predicted by different views of species and speciation, and also to see how well these predictions fare when applied to the speciation patterns found in strepsirhine primates. Theories of speciation cannot be separated from species concepts, and one concept widely supported in primatology is the Recognition Concept of species because of its heuristic nature. The Recognition Concept is based on Specific-mate Recognition Systems (SMRS). I focussed on SMRS features of Euoticus and Phaner, loud call specificity, and species’ preferred habitats. My results provided some support for the distinctiveness of currently identified species, although this was not clear-cut. Population densities of both Phaner and Euoticus appear to have declined in recent years, even though both Phaner and Euoticus appear to be well adapted to both primary and secondary forest, and exhibit ecological plasticity. Statistically some loud call parameters vary among the putative species of the genus Phaner and not Euoticus. Phaner pallescens at Kirindy, Madasgascar was clearly able to discriminate loud calls of its own population from other proposed species within the genus. Most loud call parameters did not show any statistical degradation with increasing distance. A crucial finding of my study was that the two lineages are not only convergent in terms of dietary and locomotor aspects of their ecology, but also in the structures of their loud calls. The environmental adaptation of communication systems is often overlooked when studying adaptive convergence, but my study indicates that acoustic properties are a crucial aspect of a species’ preferred habitat. The results of this study can be used to improve conservation planning, and also add to our understanding of the evolutionary history of strepsirhine primates.
- Full Text:
- Date Issued: 2016
- Authors: Forbanka, Derick Nomuh
- Date: 2016
- Subjects: Adaptation (Biology) , Mammals -- Evolution , Mammals -- Behavior
- Language: English
- Type: Thesis , Doctoral , Zoology
- Identifier: http://hdl.handle.net/10353/15957 , vital:40567
- Description: The suborder Strepsirhini contains a large proportion of the living gummivorous mammal taxa, and includes two genera of specialist gummivores, Euoticus and Phaner, which present particularly interesting cases of convergent adaptive evolution in Africa and Madagascar, respectively. Although these genera are not closely related, they share several anatomical, behavioural and physiological specialisations associated with their diets, and despite their biogeographical separation, there seems to be substantial coincidence in their habitats and habits. Neither the ecology nor the systematics of Phaner and Euoticus has been the subject of much detailed research, and little is known of the conservation status of the genera. Even their specific diversity is unresolved. In this study I investigated and compared aspects of their ecology at both a macro-and a microhabitat scale, including wild populations of all groups within the two genera that have been accorded species status in recent field guides and systematic reviews. I also studied aspects of their social communication behaviour as clues to their species-level diversity. Species and their formation (or speciation) have inspired a great deal of evolutionary research, but remain contentious issues in evolutionary biology. This is due both to the difficulties inherent in inferring the details of a dynamic biological process that occurred over some time in the past from the recent, relatively static patterns of variation observed, as well as the limited consensus among biologists in identifying such patterns. It is therefore important to distinguish the kinds of patterns in nature that are predicted by different views of species and speciation, and also to see how well these predictions fare when applied to the speciation patterns found in strepsirhine primates. Theories of speciation cannot be separated from species concepts, and one concept widely supported in primatology is the Recognition Concept of species because of its heuristic nature. The Recognition Concept is based on Specific-mate Recognition Systems (SMRS). I focussed on SMRS features of Euoticus and Phaner, loud call specificity, and species’ preferred habitats. My results provided some support for the distinctiveness of currently identified species, although this was not clear-cut. Population densities of both Phaner and Euoticus appear to have declined in recent years, even though both Phaner and Euoticus appear to be well adapted to both primary and secondary forest, and exhibit ecological plasticity. Statistically some loud call parameters vary among the putative species of the genus Phaner and not Euoticus. Phaner pallescens at Kirindy, Madasgascar was clearly able to discriminate loud calls of its own population from other proposed species within the genus. Most loud call parameters did not show any statistical degradation with increasing distance. A crucial finding of my study was that the two lineages are not only convergent in terms of dietary and locomotor aspects of their ecology, but also in the structures of their loud calls. The environmental adaptation of communication systems is often overlooked when studying adaptive convergence, but my study indicates that acoustic properties are a crucial aspect of a species’ preferred habitat. The results of this study can be used to improve conservation planning, and also add to our understanding of the evolutionary history of strepsirhine primates.
- Full Text:
- Date Issued: 2016
The development of functionalized electrospun nanofibers for the control of pathogenic microorganisms in water.
- Authors: Kleyi, Phumelele Eldridge
- Date: 2014
- Subjects: Electrospinning , Nanofibers , Pathogenic microorganisms , Pathogenic microorganisms -- Detection , Drinking water -- Microbiology , Water quality -- Measurement , Imidazoles , Spectrum analysis , Anti-infective agents , Polymerization
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4497 , http://hdl.handle.net/10962/d1013134
- Description: The thesis presents the development of functionalized electrospun nylon 6 nanofibers for the eradication of pathogenic microorganisms in drinking water. Imidazole derivatives were synthesized as the antimicrobial agents and were characterized by means of NMR spectroscopy, IR spectroscopy, elemental analysis and X-ray crystallography. The first set of compounds (2-substituted N-alkylimidazoles) consisted of imidazole derivatives substituted with different alkyl groups (methyl, ethyl, propyl, butyl, heptyl, octyl, decyl and benzyl) at the 1-position and various functional groups [carboxaldehyde (CHO), alcohol (CH2OH) and carboxylic acid (COOH)] at the 2-position. It was observed that the antimicrobial activity of the compounds increased with increasing alkyl chain length and decreasing pKa of the 2-substituent. It was also observed that the antimicrobial activity was predominantly against a Gram-positive bacterial strains [Staphylococcus aureus (MIC = 5-160 μg/mL) and Bacillus subtilis subsp. spizizenii (MIC = 5-20 μg/mL)], with the latter being the more susceptible. However, the compounds displayed poor antimicrobial activity against Gram-negative bacterial strain, E. coli (MIC = 150- >2500 μg/mL) and did not show any activity against the yeast, C. albicans. The second set of compounds consisted of the silver(I) complexes containing 2-hydroxymethyl-N-alkylimidazoles. The complexes displayed a broad spectrum antimicrobial activity towards the microorganisms that were tested and their activity [E. coli (MIC = 5-40 μg/mL), S. aureus (MIC = 20-80 μg/mL), Bacillus subtilis subsp. spizizenii (MIC = 5-40 μg/mL) and C. albicans (MIC = 40-80 μg/mL)] increased with the alkyl chain length of the 2-hydroxymethyl-N-alkylimidazole. The third set of compounds consisted of the vinylimidazoles containing the vinyl group either at the 1-position or at the 4- or 5- position. The imidazoles with the vinyl group at the 4- or 5-position contained the alkyl group (decyl) at the 1-position. For the fabrication of the antimicrobial nanofibers, the first two sets of imidazole derivatives (2-substituted N-alkylimidazoles and silver(I) complexes) were incorporated into electrospun nylon 6 nanofibers while the third set (2-substituted vinylimidazoles) was immobilized onto electrospun nylon 6 nanofibers employing the graft polymerization method. The antimicrobial nylon nanofibers were characterized by IR spectroscopy and SEM-EDAX (EDS). The electrospun nylon 6 nanofibers incorporated with 2-substituted N-alkylimidazoles displayed moderate to excellent levels of growth reduction against S. aureus (73.2-99.8 percent). For the electrospun nylon 6 nanofibers incorporated with silver(I) complexes, the levels of growth reduction were >99.99 percent, after the antimicrobial activity evaluation using the shake flask method. Furthermore, the grafted electrospun nylon 6 nanofibers showed excellent levels of growth reduction for E. coli (99.94-99.99 percent) and S. aureus (99.93-99.99 percent). The reusability results indicated that the grafted electrospun nylon 6 nanofibers maintained the antibacterial activity until the third cycle of useage. The cytotoxicity studies showed that grafted electrospun nylon 6 nanofibers possess lower cytotoxic effects on Chang liver cells with IC50 values in the range 23.48-26.81 μg/mL. The thesis demonstrated that the development of antimicrobial electrospun nanofibers, with potential for the eradication of pathogenic microoganisms in water, could be accomplished by incorporation as well as immobilization strategies.
- Full Text:
- Date Issued: 2014
- Authors: Kleyi, Phumelele Eldridge
- Date: 2014
- Subjects: Electrospinning , Nanofibers , Pathogenic microorganisms , Pathogenic microorganisms -- Detection , Drinking water -- Microbiology , Water quality -- Measurement , Imidazoles , Spectrum analysis , Anti-infective agents , Polymerization
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4497 , http://hdl.handle.net/10962/d1013134
- Description: The thesis presents the development of functionalized electrospun nylon 6 nanofibers for the eradication of pathogenic microorganisms in drinking water. Imidazole derivatives were synthesized as the antimicrobial agents and were characterized by means of NMR spectroscopy, IR spectroscopy, elemental analysis and X-ray crystallography. The first set of compounds (2-substituted N-alkylimidazoles) consisted of imidazole derivatives substituted with different alkyl groups (methyl, ethyl, propyl, butyl, heptyl, octyl, decyl and benzyl) at the 1-position and various functional groups [carboxaldehyde (CHO), alcohol (CH2OH) and carboxylic acid (COOH)] at the 2-position. It was observed that the antimicrobial activity of the compounds increased with increasing alkyl chain length and decreasing pKa of the 2-substituent. It was also observed that the antimicrobial activity was predominantly against a Gram-positive bacterial strains [Staphylococcus aureus (MIC = 5-160 μg/mL) and Bacillus subtilis subsp. spizizenii (MIC = 5-20 μg/mL)], with the latter being the more susceptible. However, the compounds displayed poor antimicrobial activity against Gram-negative bacterial strain, E. coli (MIC = 150- >2500 μg/mL) and did not show any activity against the yeast, C. albicans. The second set of compounds consisted of the silver(I) complexes containing 2-hydroxymethyl-N-alkylimidazoles. The complexes displayed a broad spectrum antimicrobial activity towards the microorganisms that were tested and their activity [E. coli (MIC = 5-40 μg/mL), S. aureus (MIC = 20-80 μg/mL), Bacillus subtilis subsp. spizizenii (MIC = 5-40 μg/mL) and C. albicans (MIC = 40-80 μg/mL)] increased with the alkyl chain length of the 2-hydroxymethyl-N-alkylimidazole. The third set of compounds consisted of the vinylimidazoles containing the vinyl group either at the 1-position or at the 4- or 5- position. The imidazoles with the vinyl group at the 4- or 5-position contained the alkyl group (decyl) at the 1-position. For the fabrication of the antimicrobial nanofibers, the first two sets of imidazole derivatives (2-substituted N-alkylimidazoles and silver(I) complexes) were incorporated into electrospun nylon 6 nanofibers while the third set (2-substituted vinylimidazoles) was immobilized onto electrospun nylon 6 nanofibers employing the graft polymerization method. The antimicrobial nylon nanofibers were characterized by IR spectroscopy and SEM-EDAX (EDS). The electrospun nylon 6 nanofibers incorporated with 2-substituted N-alkylimidazoles displayed moderate to excellent levels of growth reduction against S. aureus (73.2-99.8 percent). For the electrospun nylon 6 nanofibers incorporated with silver(I) complexes, the levels of growth reduction were >99.99 percent, after the antimicrobial activity evaluation using the shake flask method. Furthermore, the grafted electrospun nylon 6 nanofibers showed excellent levels of growth reduction for E. coli (99.94-99.99 percent) and S. aureus (99.93-99.99 percent). The reusability results indicated that the grafted electrospun nylon 6 nanofibers maintained the antibacterial activity until the third cycle of useage. The cytotoxicity studies showed that grafted electrospun nylon 6 nanofibers possess lower cytotoxic effects on Chang liver cells with IC50 values in the range 23.48-26.81 μg/mL. The thesis demonstrated that the development of antimicrobial electrospun nanofibers, with potential for the eradication of pathogenic microoganisms in water, could be accomplished by incorporation as well as immobilization strategies.
- Full Text:
- Date Issued: 2014
Social capital and fisheries co-management in South Africa: the East Coast Rock Lobster Fishery in Tshani Mankozi, Wild Coast, Eastern Cape
- Authors: Kaminsky, Alexander
- Date: 2012
- Subjects: Social capital (Sociology) -- Economic aspects Human capital -- South Africa Fishery management -- South Africa Natural resources -- Co-management -- South Africa Rural poor -- South Africa Sustainable development -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3322 , http://hdl.handle.net/10962/d1003110
- Description: It is evident that natural fish stocks are in rapid decline and that millions of people around the world rely on these resources for food and for securing a livelihood. This has brought many social scientists, biologists and fisheries experts to acknowledge that communities need to take more control in managing their natural resources. The paradigm shift in fisheries management from a top-down resource orientated control to a participatory people-centred control is now being advocated in many maritime nations in facilitating community-based natural resource management. At the heart of these projects is the establishment of institutions and social networks that allow for clear communication and information sharing, based on scientific data and traditional knowledge which ultimately allow empowered communities to collectively manage their resources in partnership with government, market actors and many other stakeholders. Central to the problem is the issue of access rights. In many situations where co-management of natural resources through community-government partnerships is advocated, the failure of coastal states to provide adequate legislature and regulatory frameworks has jeopardised such projects. A second issue is the failure of many states to provide adequate investments in social and human capital which will enable communities to become the primary stakeholder in the co-management of their natural resources. Whilst investments like capacity building, education, skills training and development, communications and institution building can initially require high financial investments, the regulatory costs for monitoring, controlling and surveying fish stocks along the coastline will go down as communities take ownership of their resources under sustainable awareness. The main unit of investment therefore is social capital which allows for the increase in trust, cooperativeness, assertiveness, collective action and general capabilities of natural resource governance. High levels of social capital require good social relations and interactions which ultimately create a social network of fishers, community members and leaders, government officials, market players, researchers and various other stakeholders. Co-management thus has an inherent network structure made up of social relations on a horizontal scale amongst community members as well as on a vertical scale with government and fisheries authorities. These bonding relations between people and the bridging relations with institutions provide the social capital currency that allows for a successful co-management solution to community-based natural resource governance. The South African coastline is home to thousands of people who harvest the marine resources for food security and securing a basic income. Fishing is a major cultural and historical component of the livelihoods of many people along the coastline, particularly along the Wild Coast of South Africa located on its South-eastern shoreline. Due to the geopolitical nature of South Africa’s apartheid past many people were located in former tribal lands called Bantustans. The Transkei, one of the biggest homelands, is home to some of South Africa’s poorest people, many of whom rely on the marine resources. By 1998 the government sought to acknowledge the previously unrecognised subsistence sector that lived along the South African coastline with the promulgation of the Marine Living Resources Act. The act sought to legalise access rights for fishers and provide opportunities for the development of commercial fisheries. The act and many subsequent policies largely called for co-management as a solution to the management of the subsistence sector. This thesis largely explains the administrative and legislative difficulties in transporting the participatory components of co-management to the ground level. As such co-management has largely remained in rhetoric whilst the government provides a contradictory policy regarding the management of subsistence and small-scale fishers. This thesis attempts to provide qualitative ethnographic research of the East Coast Rock Lobster fishery located in a small fishing village in the Transkei. The fishery falls somewhere on the spectrum between the small-scale and subsistence sector as there are a basket of high and low value resources being harvested. It will be argued that in order to economically and socially develop the fishery the social capital and social networks of the community and various stakeholders needs to be analysed in order to effectively create a co-management network that can create a successful collective management of natural resources thereby sustaining these communities in the future.
- Full Text:
- Date Issued: 2012
- Authors: Kaminsky, Alexander
- Date: 2012
- Subjects: Social capital (Sociology) -- Economic aspects Human capital -- South Africa Fishery management -- South Africa Natural resources -- Co-management -- South Africa Rural poor -- South Africa Sustainable development -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3322 , http://hdl.handle.net/10962/d1003110
- Description: It is evident that natural fish stocks are in rapid decline and that millions of people around the world rely on these resources for food and for securing a livelihood. This has brought many social scientists, biologists and fisheries experts to acknowledge that communities need to take more control in managing their natural resources. The paradigm shift in fisheries management from a top-down resource orientated control to a participatory people-centred control is now being advocated in many maritime nations in facilitating community-based natural resource management. At the heart of these projects is the establishment of institutions and social networks that allow for clear communication and information sharing, based on scientific data and traditional knowledge which ultimately allow empowered communities to collectively manage their resources in partnership with government, market actors and many other stakeholders. Central to the problem is the issue of access rights. In many situations where co-management of natural resources through community-government partnerships is advocated, the failure of coastal states to provide adequate legislature and regulatory frameworks has jeopardised such projects. A second issue is the failure of many states to provide adequate investments in social and human capital which will enable communities to become the primary stakeholder in the co-management of their natural resources. Whilst investments like capacity building, education, skills training and development, communications and institution building can initially require high financial investments, the regulatory costs for monitoring, controlling and surveying fish stocks along the coastline will go down as communities take ownership of their resources under sustainable awareness. The main unit of investment therefore is social capital which allows for the increase in trust, cooperativeness, assertiveness, collective action and general capabilities of natural resource governance. High levels of social capital require good social relations and interactions which ultimately create a social network of fishers, community members and leaders, government officials, market players, researchers and various other stakeholders. Co-management thus has an inherent network structure made up of social relations on a horizontal scale amongst community members as well as on a vertical scale with government and fisheries authorities. These bonding relations between people and the bridging relations with institutions provide the social capital currency that allows for a successful co-management solution to community-based natural resource governance. The South African coastline is home to thousands of people who harvest the marine resources for food security and securing a basic income. Fishing is a major cultural and historical component of the livelihoods of many people along the coastline, particularly along the Wild Coast of South Africa located on its South-eastern shoreline. Due to the geopolitical nature of South Africa’s apartheid past many people were located in former tribal lands called Bantustans. The Transkei, one of the biggest homelands, is home to some of South Africa’s poorest people, many of whom rely on the marine resources. By 1998 the government sought to acknowledge the previously unrecognised subsistence sector that lived along the South African coastline with the promulgation of the Marine Living Resources Act. The act sought to legalise access rights for fishers and provide opportunities for the development of commercial fisheries. The act and many subsequent policies largely called for co-management as a solution to the management of the subsistence sector. This thesis largely explains the administrative and legislative difficulties in transporting the participatory components of co-management to the ground level. As such co-management has largely remained in rhetoric whilst the government provides a contradictory policy regarding the management of subsistence and small-scale fishers. This thesis attempts to provide qualitative ethnographic research of the East Coast Rock Lobster fishery located in a small fishing village in the Transkei. The fishery falls somewhere on the spectrum between the small-scale and subsistence sector as there are a basket of high and low value resources being harvested. It will be argued that in order to economically and socially develop the fishery the social capital and social networks of the community and various stakeholders needs to be analysed in order to effectively create a co-management network that can create a successful collective management of natural resources thereby sustaining these communities in the future.
- Full Text:
- Date Issued: 2012
Towards monitoring that makes sense : action research design of a planning, learning and accountability system for a sustainable agriculture programme in Eastern Indonesia
- Authors: Deprez, Stefan Gert Marie
- Date: 2011
- Subjects: Agricultural development projects -- Indonesia Agricultural administration -- Monitoring -- Indonesia Action research -- Case studies Action research in education
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1801 , http://hdl.handle.net/10962/d1003686
- Description: This study is an account of an action research process to develop a planning, learning and accountability (PLA) system for the sustainable agriculture chain development programme of VECO (Vredeseilanden Country Office) Indonesia. Many monitoring and evaluation (M&E) processes in development programmes are largely carried out to provide information for funding agencies, to meet external accountability requirements and for symbolic protection. This study generates insights into an integrated, learning-oriented monitoring practice which fosters reflective practice, provides feedback to programme stakeholders about performance, progress and results achieved, facilitates improved accountability, and generates information and knowledge useful for the programme stakeholders to take decisions for improved action. It is argued that M&E systems have the potential, if developed well, to serve as a framework or ‘carrier’ for organisational and institutional learning – an essential requirement to respond to the complex nature of development processes. Outcome mapping is presented as a possible approach to be used as the basis for such a M&E system. This study was underpinned by a socially critical orientation to development (programmes) and by an action research method to guide the PLA system design process. The design process was organized around seven steps - which in themselves were a result of the action research process – including specific steps to ensure a learning-oriented M&E system. Based on the agreed purposes and intended uses of the monitoring and learning process, the resulting PLA system is focused around the organizational spaces and rhythms of VECO Indonesia which are central to sharing, debate, learning and decision-making. In this way, the PLA system becomes integral to the thinking and doing of the organization. It is built on the premise that monitoring does not end with gathering data; it also needs to include a process of understanding and deciding how data can best be used and analysed to strengthen concerted action and facilitate decision-making. It highlights the importance of sense-making – interpreting information to make it usable for action. Furthermore, it incorporates an approach to assess and consciously plan for the creation of the necessary organisational conditions to implement and maintain a learning-oriented M&E system. The study is completed by critical reflection on the relevance of VECO’s new PLA system for planning, learning and accountability, combined with the use of a future scenario technique to generate recommendations and identify critical future directions. Further exploration of ‘intelligent’ information-seeking methods and processes is called for; and a practice which moves beyond intra-organisational monitoring – focusing on VECO’s own monitoring needs – towards a monitoring process that facilitates change based on the viewpoints of, and in collaboration with local actors, i.e., institutional monitoring and learning, is recommended. VECO is encouraged to continue developing a mindset and practice whereby the programme team and partners have the ability to leave the safe zone of pre-determined outcomes and actions, and to make sense of the world as they engage in action.
- Full Text:
- Date Issued: 2011
- Authors: Deprez, Stefan Gert Marie
- Date: 2011
- Subjects: Agricultural development projects -- Indonesia Agricultural administration -- Monitoring -- Indonesia Action research -- Case studies Action research in education
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1801 , http://hdl.handle.net/10962/d1003686
- Description: This study is an account of an action research process to develop a planning, learning and accountability (PLA) system for the sustainable agriculture chain development programme of VECO (Vredeseilanden Country Office) Indonesia. Many monitoring and evaluation (M&E) processes in development programmes are largely carried out to provide information for funding agencies, to meet external accountability requirements and for symbolic protection. This study generates insights into an integrated, learning-oriented monitoring practice which fosters reflective practice, provides feedback to programme stakeholders about performance, progress and results achieved, facilitates improved accountability, and generates information and knowledge useful for the programme stakeholders to take decisions for improved action. It is argued that M&E systems have the potential, if developed well, to serve as a framework or ‘carrier’ for organisational and institutional learning – an essential requirement to respond to the complex nature of development processes. Outcome mapping is presented as a possible approach to be used as the basis for such a M&E system. This study was underpinned by a socially critical orientation to development (programmes) and by an action research method to guide the PLA system design process. The design process was organized around seven steps - which in themselves were a result of the action research process – including specific steps to ensure a learning-oriented M&E system. Based on the agreed purposes and intended uses of the monitoring and learning process, the resulting PLA system is focused around the organizational spaces and rhythms of VECO Indonesia which are central to sharing, debate, learning and decision-making. In this way, the PLA system becomes integral to the thinking and doing of the organization. It is built on the premise that monitoring does not end with gathering data; it also needs to include a process of understanding and deciding how data can best be used and analysed to strengthen concerted action and facilitate decision-making. It highlights the importance of sense-making – interpreting information to make it usable for action. Furthermore, it incorporates an approach to assess and consciously plan for the creation of the necessary organisational conditions to implement and maintain a learning-oriented M&E system. The study is completed by critical reflection on the relevance of VECO’s new PLA system for planning, learning and accountability, combined with the use of a future scenario technique to generate recommendations and identify critical future directions. Further exploration of ‘intelligent’ information-seeking methods and processes is called for; and a practice which moves beyond intra-organisational monitoring – focusing on VECO’s own monitoring needs – towards a monitoring process that facilitates change based on the viewpoints of, and in collaboration with local actors, i.e., institutional monitoring and learning, is recommended. VECO is encouraged to continue developing a mindset and practice whereby the programme team and partners have the ability to leave the safe zone of pre-determined outcomes and actions, and to make sense of the world as they engage in action.
- Full Text:
- Date Issued: 2011
Investigating the effects of form-focused activities on the Acquisition of articles and pronouns in English amongst Grade 11 Xhosa learners
- Authors: White, Emma Lindsey
- Date: 2010
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:8362 , http://hdl.handle.net/10948/1317
- Description: The main purpose of this dissertation is to investigate if a teaching method called Focus on Form (FonF) in an English as a Second Language (ESL) class is effective in the acquisition of two grammatical forms namely articles ("a", "an" and "the") and a selection of pronouns. In order to test this hypothesis, quantitative research was performed. The analysis of a series of tests was done quantitatively to prove the hypothesis. The dissertation includes a theory section on Social Capital (SC) and discusses why it might play an important part in South Africa and in offering some help to the communities to enable them to help in the education of their children within South Africa. This dissertation is divided into five chapters. The first chapter introduces the problem and explains how South African education, historically, had devastating effects in the past and continues having a far reaching effect on today‟s learners. It discusses why this dissertation focuses on English and highlights how extensively English has spread throughout the world. It contains an explanation of the value of being competent in the English language. The chapter continues with a depiction of the poor pass rates of the end of year high school examinations, The National Senior Certificate (NSC). It explains the significance of the research, the purpose of the study, its theoretical framework and finally what this study proposes. Chapter two is a literature review of the available literature discussing second language acquisition (SLA) and the difference between English as a Foreign Language (EFL) and English as a Second Language (ESL). The chapter continues with a detailed description of how English was taught historically with an explanation of the approach being used in this study. Chapter two continues with details of the historical "Bantu Education Act No 47 of 1953" and the racist policies of the government of the time with an exploration of the effect these policies had on the education of learners. It also specifies the grammatical forms being used in this study. A summary of Black South African English (BSAE) is included accompanied by a description of language transfer. The chapter contains a section on SC, with an explanation of how this term came about historically and what it means. The chapter includes social problems that South Africa is facing today and how these problems tie in with diminished SC. It explains the importance of SC in Education. The chapter concludes with an explanation of how SC can be utilized in communities and why it is important in a democratic country. Chapter three explains the methodology used in this study as that of positivism and that this study in one sense is purely an empirical study and the reasons behind the choice of methodology. It also explains how a section of this study is pragmatic. Although the testing and analysis is purely statistical, the lessons that took place in the classroom, the interpersonal communication combined with the interaction between the learners and the researcher was not quantitative in nature. This interaction had no outright bearing on the results, but allowed the researcher the opportunity to observe and take notes on the experiences of the learners and the researcher in the classroom. These observations included incidents within the lessons and external problems the learners face which are linked to social issues within the literature. The chapter also contains an explanation of the testing instruments used in this study and how they were developed along with the ethical considerations of the study. Chapter four details the statistical results of this study. It also contains the write up of the field notes of the researcher who took note of incidents that happened within the classes. There are some examples of family and personal problems related to the learners and details the environment of the school. Some of these issues tie in with the theory included; illustrating the ideas and concerns associated with SC and demonstrates how these social problems are truly part of each learner‟s life in a township school. Chapter five offers recommendations to English teachers, the Department of Education (DoE) and to future researchers based on the results of Chapter four. It contains a discussion on how the community can increase SC within their own areas and within the schools. This study argues that the Education system is in dire need of help as evidenced by the dismal exam results. It also argues that South Africa has a variety of social problems that are contributing to the overall failure and dropout rate in schools. It offers some general suggestions on how the community can work together to build systems within the community, to help themselves and their children to become educated, productive members of society. The only way for the children of South Africa to succeed is with a good education as their starting point.
- Full Text:
- Date Issued: 2010
- Authors: White, Emma Lindsey
- Date: 2010
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:8362 , http://hdl.handle.net/10948/1317
- Description: The main purpose of this dissertation is to investigate if a teaching method called Focus on Form (FonF) in an English as a Second Language (ESL) class is effective in the acquisition of two grammatical forms namely articles ("a", "an" and "the") and a selection of pronouns. In order to test this hypothesis, quantitative research was performed. The analysis of a series of tests was done quantitatively to prove the hypothesis. The dissertation includes a theory section on Social Capital (SC) and discusses why it might play an important part in South Africa and in offering some help to the communities to enable them to help in the education of their children within South Africa. This dissertation is divided into five chapters. The first chapter introduces the problem and explains how South African education, historically, had devastating effects in the past and continues having a far reaching effect on today‟s learners. It discusses why this dissertation focuses on English and highlights how extensively English has spread throughout the world. It contains an explanation of the value of being competent in the English language. The chapter continues with a depiction of the poor pass rates of the end of year high school examinations, The National Senior Certificate (NSC). It explains the significance of the research, the purpose of the study, its theoretical framework and finally what this study proposes. Chapter two is a literature review of the available literature discussing second language acquisition (SLA) and the difference between English as a Foreign Language (EFL) and English as a Second Language (ESL). The chapter continues with a detailed description of how English was taught historically with an explanation of the approach being used in this study. Chapter two continues with details of the historical "Bantu Education Act No 47 of 1953" and the racist policies of the government of the time with an exploration of the effect these policies had on the education of learners. It also specifies the grammatical forms being used in this study. A summary of Black South African English (BSAE) is included accompanied by a description of language transfer. The chapter contains a section on SC, with an explanation of how this term came about historically and what it means. The chapter includes social problems that South Africa is facing today and how these problems tie in with diminished SC. It explains the importance of SC in Education. The chapter concludes with an explanation of how SC can be utilized in communities and why it is important in a democratic country. Chapter three explains the methodology used in this study as that of positivism and that this study in one sense is purely an empirical study and the reasons behind the choice of methodology. It also explains how a section of this study is pragmatic. Although the testing and analysis is purely statistical, the lessons that took place in the classroom, the interpersonal communication combined with the interaction between the learners and the researcher was not quantitative in nature. This interaction had no outright bearing on the results, but allowed the researcher the opportunity to observe and take notes on the experiences of the learners and the researcher in the classroom. These observations included incidents within the lessons and external problems the learners face which are linked to social issues within the literature. The chapter also contains an explanation of the testing instruments used in this study and how they were developed along with the ethical considerations of the study. Chapter four details the statistical results of this study. It also contains the write up of the field notes of the researcher who took note of incidents that happened within the classes. There are some examples of family and personal problems related to the learners and details the environment of the school. Some of these issues tie in with the theory included; illustrating the ideas and concerns associated with SC and demonstrates how these social problems are truly part of each learner‟s life in a township school. Chapter five offers recommendations to English teachers, the Department of Education (DoE) and to future researchers based on the results of Chapter four. It contains a discussion on how the community can increase SC within their own areas and within the schools. This study argues that the Education system is in dire need of help as evidenced by the dismal exam results. It also argues that South Africa has a variety of social problems that are contributing to the overall failure and dropout rate in schools. It offers some general suggestions on how the community can work together to build systems within the community, to help themselves and their children to become educated, productive members of society. The only way for the children of South Africa to succeed is with a good education as their starting point.
- Full Text:
- Date Issued: 2010
The politics of planning in Eastern Cape local government: a case study of Ngqushwa and Buffalo City, 1998-2004
- Authors: Hollands, Glenn Delroy
- Date: 2007
- Subjects: Buffalo City (South Africa) Local government -- South Africa -- Eastern Cape -- Case studies Municipal government -- South Africa -- Eastern Cape -- Case studies Political planning -- South Africa -- Eastern Cape Eastern Cape (South Africa) -- History -- 20th century Eastern Cape (South Africa) -- History -- 21st century
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2875 , http://hdl.handle.net/10962/d1008199
- Description: This thesis examines the political implications of the integrated development planning process embarked upon by South African municipalities in the period 1998-2004. Through the use of case study methodology that focuses on the Eastern Cape municipalities of Buffalo City and Ngqushwa, the conventions of municipal planning are examined. This inquiry into municipal planning draws upon official government documents and reports and publications from the nongovernment sector. The thesis is particularly focused on the claims made in policy documents and related secondary sources and compares these to more critical reports and publication as well as the author's personal experience of the integrated development planning process. Of key interest is the possibility that planning serves political interests and the material needs of an emerging municipal elite and that this is seldom acknowledged in official planning documentation or government sanctioned publications on the topic. The primary findings of the thesis are as follows: • That the 'reason' of expert policy formulations that accompanied integrated development planning has weakened political economy as a prism of understanding and separated itself from the institutional reality of municipal government • That the dominant critique of planning and other post-apartheid municipal policy is concerned with the triumph of neoliberalism but this critique, while valid, does not fully explain successive policy failures especially in the setting of Eastern Cape local government • That function of policy and its relationship to both the state and civil society is usually understood only in the most obvious sense and not as an instrument for wielding political power • That planning still derives much of its influence from its claim to technical rationality and that this underpinned the 'authority' of the integrated development planning project in South Africa and reinforced its power to make communities governable.
- Full Text:
- Date Issued: 2007
- Authors: Hollands, Glenn Delroy
- Date: 2007
- Subjects: Buffalo City (South Africa) Local government -- South Africa -- Eastern Cape -- Case studies Municipal government -- South Africa -- Eastern Cape -- Case studies Political planning -- South Africa -- Eastern Cape Eastern Cape (South Africa) -- History -- 20th century Eastern Cape (South Africa) -- History -- 21st century
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2875 , http://hdl.handle.net/10962/d1008199
- Description: This thesis examines the political implications of the integrated development planning process embarked upon by South African municipalities in the period 1998-2004. Through the use of case study methodology that focuses on the Eastern Cape municipalities of Buffalo City and Ngqushwa, the conventions of municipal planning are examined. This inquiry into municipal planning draws upon official government documents and reports and publications from the nongovernment sector. The thesis is particularly focused on the claims made in policy documents and related secondary sources and compares these to more critical reports and publication as well as the author's personal experience of the integrated development planning process. Of key interest is the possibility that planning serves political interests and the material needs of an emerging municipal elite and that this is seldom acknowledged in official planning documentation or government sanctioned publications on the topic. The primary findings of the thesis are as follows: • That the 'reason' of expert policy formulations that accompanied integrated development planning has weakened political economy as a prism of understanding and separated itself from the institutional reality of municipal government • That the dominant critique of planning and other post-apartheid municipal policy is concerned with the triumph of neoliberalism but this critique, while valid, does not fully explain successive policy failures especially in the setting of Eastern Cape local government • That function of policy and its relationship to both the state and civil society is usually understood only in the most obvious sense and not as an instrument for wielding political power • That planning still derives much of its influence from its claim to technical rationality and that this underpinned the 'authority' of the integrated development planning project in South Africa and reinforced its power to make communities governable.
- Full Text:
- Date Issued: 2007
A development and management framework for a new Octopus vulgaris fishery in South Africa
- Authors: Oosthuizen, Ané
- Date: 2004
- Subjects: Common octopus -- South Africa Octopus fisheries -- South Africa Octopus fisheries -- South Africa -- Economic aspects Fishery management -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5255 , http://hdl.handle.net/10962/d1005098
- Description: A new policy incorporating an operational protocol was developed for the establishment of new fisheries in South Africa. The common octopus, Octopus vulgaris was used as a candidate species for the project. The operational protocol consisted of a three-phased development framework, namely information gathering (Phase 0), an experimental fishery (Phase 1) and the final implementation of a commercial fishery (Phase 2). The present study focussed on phase 0 of this theoretical framework and protocol and was implemented by using a proposed octopus pot fishery in South Africa as a case study. Phase 0 included a desktop study, information gathering in the field, an economic feasibility study and the formulation of a Fishery Management Plan and experimental design for the fishery. Information gaps identified during the desktop study were addressed during field investigations into the population structure and biology of O. vulgaris along the southeast coast. Immature females were found to use the intertidal area to feed and grow before migrating to the subtidal area to mature and spawn. Mean size differed substantially between intertidal and subtidal areas, with larger octopus found subtidally. Age and growth trials using tetracycline as a marker showed that O. vulgaris deposit daily growth lines in their beaks. A genetic study showed that there is most likely only one panmitic population along the coast. The economic feasibility study indicated that a longline pot fishery could be feasible provided a 30% catch in 6600 pots/month is attained. Only existing, debt-free vessels should be used in this fishery. The Fishery Management Plan proposed in this study includes management measures such as effort limitation of licences and gear, size restrictions, vessel monitoring systems, and observer programmes. Based on the population dynamics and biology of O. vulgaris it is suggested that a precautionary approach to developing fisheries for this species in both the inter- and subtidal areas along the South African coast.
- Full Text:
- Date Issued: 2004
- Authors: Oosthuizen, Ané
- Date: 2004
- Subjects: Common octopus -- South Africa Octopus fisheries -- South Africa Octopus fisheries -- South Africa -- Economic aspects Fishery management -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5255 , http://hdl.handle.net/10962/d1005098
- Description: A new policy incorporating an operational protocol was developed for the establishment of new fisheries in South Africa. The common octopus, Octopus vulgaris was used as a candidate species for the project. The operational protocol consisted of a three-phased development framework, namely information gathering (Phase 0), an experimental fishery (Phase 1) and the final implementation of a commercial fishery (Phase 2). The present study focussed on phase 0 of this theoretical framework and protocol and was implemented by using a proposed octopus pot fishery in South Africa as a case study. Phase 0 included a desktop study, information gathering in the field, an economic feasibility study and the formulation of a Fishery Management Plan and experimental design for the fishery. Information gaps identified during the desktop study were addressed during field investigations into the population structure and biology of O. vulgaris along the southeast coast. Immature females were found to use the intertidal area to feed and grow before migrating to the subtidal area to mature and spawn. Mean size differed substantially between intertidal and subtidal areas, with larger octopus found subtidally. Age and growth trials using tetracycline as a marker showed that O. vulgaris deposit daily growth lines in their beaks. A genetic study showed that there is most likely only one panmitic population along the coast. The economic feasibility study indicated that a longline pot fishery could be feasible provided a 30% catch in 6600 pots/month is attained. Only existing, debt-free vessels should be used in this fishery. The Fishery Management Plan proposed in this study includes management measures such as effort limitation of licences and gear, size restrictions, vessel monitoring systems, and observer programmes. Based on the population dynamics and biology of O. vulgaris it is suggested that a precautionary approach to developing fisheries for this species in both the inter- and subtidal areas along the South African coast.
- Full Text:
- Date Issued: 2004
Chemical studies of chromone derivatives
- Authors: Sabbagh, Liezel Veronica
- Date: 2001
- Subjects: Benzopyrans Heterocyclic compounds -- Derivatives Coumarins
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4424 , http://hdl.handle.net/10962/d1006899
- Description:
This study has focussed on several aspects of chromone chemistry, viz., (i) the influence of remote substituents on the basicity of 2-(N,N-dimethylamino)chromones, (ii) MoritaBaylis-Hillman reactions of substituted chromone-3-carbaldehydes and (iii) an investigation into the application of chromone chemistry in the total synthesis of the marine natural product, Rietone A. Selected 2-(N,N-dimethylamino )chromones were prepared using two different methods; firstly, via cyclisation of salicylate-derived N,N-dimethyl-3;.(2-hydroxyphenyl)-3- oxopropanamide precursors and, secondly, via 2-hydroxyacetophenone boron difluoride complexes. ¹³C NMR analysis of the 6- and 7-methoxy-2-(N,N-dimethylamino)chromones confirmed that protonation occurs at the chromone carbonyl oxygen rather than the amino nitrogen - a conclusion supported by mol~cular orbital calculations. Potentiometric analysis of 2-(N,N-dimethylamino )chromones in ethanol-water afforded pKa (pK [subscript a]) values in the range 2.22 - 2.52. The observed trend has been rationalised in terms of substituent effects with the aid of molecular orbital calculations at the semi-empirical and ab initio levels, while hydrogen-bonding effects have been used to account for the apparently anomalous result obtained for the 6-nitro derivative. A series of seven substituted chromone-3-carbaldehydes, prepared by the application of Vilsmeier-Haack methodology to the corresponding 2-hydroxyacetophenones, have been examined as substrates for Morita-Baylis-Hillman reactions, using DABCO as the catalyst and three different activated alkenes, viz., methyl acrylate, methyl vinyl ketone and acrylonitrile. In all cases, with the exception of 6-nitrochromone-3-carbaldehyde, the reactions have been shown to afford the expected Morita-Baylis-Hillman products. Use of methyl acrylate and methyl vinyl ketone as the activated alkene has been observed to afford additional, unprecedented dimeric products, which have been unambiguously characterised using a combination of single crystal X-ray analysis and spectroscopic (high resolution MS and NMR) techniques. Different dimer-like adducts have been isolated from reactions in which acrylonitrile was used as the activated alkene, and the structures of these novel products have-been determined
- Full Text:
- Date Issued: 2001
- Authors: Sabbagh, Liezel Veronica
- Date: 2001
- Subjects: Benzopyrans Heterocyclic compounds -- Derivatives Coumarins
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4424 , http://hdl.handle.net/10962/d1006899
- Description:
This study has focussed on several aspects of chromone chemistry, viz., (i) the influence of remote substituents on the basicity of 2-(N,N-dimethylamino)chromones, (ii) MoritaBaylis-Hillman reactions of substituted chromone-3-carbaldehydes and (iii) an investigation into the application of chromone chemistry in the total synthesis of the marine natural product, Rietone A. Selected 2-(N,N-dimethylamino )chromones were prepared using two different methods; firstly, via cyclisation of salicylate-derived N,N-dimethyl-3;.(2-hydroxyphenyl)-3- oxopropanamide precursors and, secondly, via 2-hydroxyacetophenone boron difluoride complexes. ¹³C NMR analysis of the 6- and 7-methoxy-2-(N,N-dimethylamino)chromones confirmed that protonation occurs at the chromone carbonyl oxygen rather than the amino nitrogen - a conclusion supported by mol~cular orbital calculations. Potentiometric analysis of 2-(N,N-dimethylamino )chromones in ethanol-water afforded pKa (pK [subscript a]) values in the range 2.22 - 2.52. The observed trend has been rationalised in terms of substituent effects with the aid of molecular orbital calculations at the semi-empirical and ab initio levels, while hydrogen-bonding effects have been used to account for the apparently anomalous result obtained for the 6-nitro derivative. A series of seven substituted chromone-3-carbaldehydes, prepared by the application of Vilsmeier-Haack methodology to the corresponding 2-hydroxyacetophenones, have been examined as substrates for Morita-Baylis-Hillman reactions, using DABCO as the catalyst and three different activated alkenes, viz., methyl acrylate, methyl vinyl ketone and acrylonitrile. In all cases, with the exception of 6-nitrochromone-3-carbaldehyde, the reactions have been shown to afford the expected Morita-Baylis-Hillman products. Use of methyl acrylate and methyl vinyl ketone as the activated alkene has been observed to afford additional, unprecedented dimeric products, which have been unambiguously characterised using a combination of single crystal X-ray analysis and spectroscopic (high resolution MS and NMR) techniques. Different dimer-like adducts have been isolated from reactions in which acrylonitrile was used as the activated alkene, and the structures of these novel products have-been determined
- Full Text:
- Date Issued: 2001
Ecology of the ichthyofauna in three temporarily open/closed estuaries on the Natal coast
- Authors: Harrison, Trevor D
- Date: 1994
- Subjects: Estuarine ecology -- South Africa -- KwaZulu-Natal , Estuarine animals -- South Africa -- Swartkops River Estuary , Fishes -- South Africa -- KwaZulu-Natal
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5269 , http://hdl.handle.net/10962/d1005113 , Estuarine ecology -- South Africa -- KwaZulu-Natal , Estuarine animals -- South Africa -- Swartkops River Estuary , Fishes -- South Africa -- KwaZulu-Natal
- Description: The ichthyofauna of three small Natal estuaries, the Mhlanga, Damba and Zotsha was sampled over a period of two years. A total of 68 kinds of fishes representing 24 families, 39 genera and 56 species were captured during this study. Forty seven kinds of fishes were recorded in the Mhlanga of which Gilchristella aestuaria,Oreochromis mossambicus, Valamugil cunnesius, Valamugil sp. and juvenile mugilids numerically dominated. In terms of biomass, O. mossambicus, V. cunnesius, Liza alata, Myxus capensis and Mugil cephalus dominated the ichthyofauna of the Mhlanga. In the Damba, 24 kinds of fishes were recorded. The most abundant fishes captured were Glossogobius callidus, M. capensis and O. mossambicus. M. capensis, M. cephalus, O. mossambicus and G. callidus dominated the fish biomass captured in the Damba. A total of 56 kinds of fishes were recorded in the Zotsha during this study. The ichthyofauna of the Zotsha was numerically dominated by juvenile mugilids, G. aestuaria, O. mossambicus, Rhabdosargus holubi, Terapon jarbua, Ambassis productus and G. callidus. The species which dominated the fish biomass in the Zotsha were O. mossambicus, L. alata, Valamugil robustus, Valamugil buchanani, M. capensis, M. cephalus and V. cunnesius. Classifying the species captured according to whether they were resident estuarine species, freshwater species, estuarine-dependent marine species and marine species revealed that the first three groups were all well represented in the systems. The only system in which marine species made any significant contribution to the ichthyofauna was the Zotsha. Oreochromis mossambicus was the dominant freshwater species in all three estuaries during this study. Gilchristella aestuaria and Glossogobius callidus were the principal estuarine species in the Mhlanga and the Damba respectively. Both G. aestuaria and G. callidus were the dominant estuarine species captured in the Zotsha. The principal estuarine-dependent marine fishes captured in the Mhlanga were V. cunnesius, Valamugil sp., juvenile mugilids, M. capensis, M. cephalus and L. alata. In the Damba, M. capensis and M. cephalus were the dominant estuarine-dependent marine species and in the Zotsha juvenile mugilids, R. holubi, T. jarbua, A . productus, M. capensis, V. cunnesius, V. robustus, M. cephalus and L. alata predominated. The results of this study indicate that the estuaries are dominated at different periods by different assemblages of fishes. This is linked to the spawning and migration patterns of the various species as well as the hydrological regime of each estuary. During the winter these systems are normally closed with relatively deep waters and high food resource and habitat availability. Freshwater and estuarine species mainly inhabit the upper reaches of the systems while estuarine-dependent marine species mainly occupy the middle and lower reaches and dominate the fish community. When these systems open with the onset of the spring/summer rains, adult and sub-adult estuarine-dependent marine species emigrate to the marine environment and juveniles begin recruiting into the systems. Spring is also the peak breeding period of resident estuarine and freshwater species, resulting in an increase in the contribution of these fishes to the overall population during this period. When closed estuaries open many of them drain and this results in the fishes concentrating in the lower reaches of the system where moderate water depths are present, thus further contributing to an increase in the proportion of freshwater and estuarine species in this region. The breaching of closed estuaries also results in a slump in food resources and habitat availability. Competition and possible increased vulnerability to avian predation (due to the shallow nature of the systems), may contribute to a decrease in the proportion of estuarine and freshwater species in summer. The prolonged spawning and recruitment of 0+ juveniles of estuarine-dependent marine species results in an increase in the proportion of these fishes present in the estuaries during summer. In autumn, these systems normally close, water levels rise and available food resources and habitat increase. This allows the redistribution of freshwater and estuarine species upstream, leaving estuarine-dependent marine species to dominate the middle and lower reaches. Although temporarily open/closed estuaries along the Natal coast may not be as diverse as permanently open estuaries in terms of their ichthyofauna, their importance must not be underestimated since by providing a continuous sequence of sheltered habitats along the coast they may contribute significantly to the viability of estuarine-dependent marine fish stocks.
- Full Text:
- Date Issued: 1994
- Authors: Harrison, Trevor D
- Date: 1994
- Subjects: Estuarine ecology -- South Africa -- KwaZulu-Natal , Estuarine animals -- South Africa -- Swartkops River Estuary , Fishes -- South Africa -- KwaZulu-Natal
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5269 , http://hdl.handle.net/10962/d1005113 , Estuarine ecology -- South Africa -- KwaZulu-Natal , Estuarine animals -- South Africa -- Swartkops River Estuary , Fishes -- South Africa -- KwaZulu-Natal
- Description: The ichthyofauna of three small Natal estuaries, the Mhlanga, Damba and Zotsha was sampled over a period of two years. A total of 68 kinds of fishes representing 24 families, 39 genera and 56 species were captured during this study. Forty seven kinds of fishes were recorded in the Mhlanga of which Gilchristella aestuaria,Oreochromis mossambicus, Valamugil cunnesius, Valamugil sp. and juvenile mugilids numerically dominated. In terms of biomass, O. mossambicus, V. cunnesius, Liza alata, Myxus capensis and Mugil cephalus dominated the ichthyofauna of the Mhlanga. In the Damba, 24 kinds of fishes were recorded. The most abundant fishes captured were Glossogobius callidus, M. capensis and O. mossambicus. M. capensis, M. cephalus, O. mossambicus and G. callidus dominated the fish biomass captured in the Damba. A total of 56 kinds of fishes were recorded in the Zotsha during this study. The ichthyofauna of the Zotsha was numerically dominated by juvenile mugilids, G. aestuaria, O. mossambicus, Rhabdosargus holubi, Terapon jarbua, Ambassis productus and G. callidus. The species which dominated the fish biomass in the Zotsha were O. mossambicus, L. alata, Valamugil robustus, Valamugil buchanani, M. capensis, M. cephalus and V. cunnesius. Classifying the species captured according to whether they were resident estuarine species, freshwater species, estuarine-dependent marine species and marine species revealed that the first three groups were all well represented in the systems. The only system in which marine species made any significant contribution to the ichthyofauna was the Zotsha. Oreochromis mossambicus was the dominant freshwater species in all three estuaries during this study. Gilchristella aestuaria and Glossogobius callidus were the principal estuarine species in the Mhlanga and the Damba respectively. Both G. aestuaria and G. callidus were the dominant estuarine species captured in the Zotsha. The principal estuarine-dependent marine fishes captured in the Mhlanga were V. cunnesius, Valamugil sp., juvenile mugilids, M. capensis, M. cephalus and L. alata. In the Damba, M. capensis and M. cephalus were the dominant estuarine-dependent marine species and in the Zotsha juvenile mugilids, R. holubi, T. jarbua, A . productus, M. capensis, V. cunnesius, V. robustus, M. cephalus and L. alata predominated. The results of this study indicate that the estuaries are dominated at different periods by different assemblages of fishes. This is linked to the spawning and migration patterns of the various species as well as the hydrological regime of each estuary. During the winter these systems are normally closed with relatively deep waters and high food resource and habitat availability. Freshwater and estuarine species mainly inhabit the upper reaches of the systems while estuarine-dependent marine species mainly occupy the middle and lower reaches and dominate the fish community. When these systems open with the onset of the spring/summer rains, adult and sub-adult estuarine-dependent marine species emigrate to the marine environment and juveniles begin recruiting into the systems. Spring is also the peak breeding period of resident estuarine and freshwater species, resulting in an increase in the contribution of these fishes to the overall population during this period. When closed estuaries open many of them drain and this results in the fishes concentrating in the lower reaches of the system where moderate water depths are present, thus further contributing to an increase in the proportion of freshwater and estuarine species in this region. The breaching of closed estuaries also results in a slump in food resources and habitat availability. Competition and possible increased vulnerability to avian predation (due to the shallow nature of the systems), may contribute to a decrease in the proportion of estuarine and freshwater species in summer. The prolonged spawning and recruitment of 0+ juveniles of estuarine-dependent marine species results in an increase in the proportion of these fishes present in the estuaries during summer. In autumn, these systems normally close, water levels rise and available food resources and habitat increase. This allows the redistribution of freshwater and estuarine species upstream, leaving estuarine-dependent marine species to dominate the middle and lower reaches. Although temporarily open/closed estuaries along the Natal coast may not be as diverse as permanently open estuaries in terms of their ichthyofauna, their importance must not be underestimated since by providing a continuous sequence of sheltered habitats along the coast they may contribute significantly to the viability of estuarine-dependent marine fish stocks.
- Full Text:
- Date Issued: 1994
Identification and analysis of manual materials handling tasks within a commercial warehouse in South Africa
- Authors: Walraven, Lynne Louise
- Date: 1989
- Subjects: Materials handling -- Safety measures , Industrial safety -- South Africa , Lifting and carrying -- Safety measures
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:5159 , http://hdl.handle.net/10962/d1015722
- Description: Lifting and overstraining are major causative factors related to musculoskeletal injuries and low back pain. A great number of work-related injuries arise from the handling and/or mishandling of materials. Hence there is a need to quantify risk factors in situ and develop guidelines for safe lifting practises in industry. The aim of this study was to make appropriate in situ quantification, within a commercial warehouse, of the stresses and physical demands imposed on the worker when performing two handed lifts in the sagittal plane. The performance of employees was assessed under normal working conditions through an observational methodology of data collection. Task performance evaluation was based on detailed measurement of all containers handled, an activity and time analysis, and the 'Work Practices Guide to Manual Lifting’ (NIOSH, 1981) which was used as the primary guide to developing theoretical recommendations to probable MMH risk factors for the workers involved. Of the 191 tasks analysed 103 were deemed unsuitable. Appropriate task factor adjustments were made where necessary to both the frequency and Hfactors (horizontal distance between the centre of gravity of the container and that of the worker) in order to reduce the risk factor for the workers
- Full Text:
- Date Issued: 1989
- Authors: Walraven, Lynne Louise
- Date: 1989
- Subjects: Materials handling -- Safety measures , Industrial safety -- South Africa , Lifting and carrying -- Safety measures
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:5159 , http://hdl.handle.net/10962/d1015722
- Description: Lifting and overstraining are major causative factors related to musculoskeletal injuries and low back pain. A great number of work-related injuries arise from the handling and/or mishandling of materials. Hence there is a need to quantify risk factors in situ and develop guidelines for safe lifting practises in industry. The aim of this study was to make appropriate in situ quantification, within a commercial warehouse, of the stresses and physical demands imposed on the worker when performing two handed lifts in the sagittal plane. The performance of employees was assessed under normal working conditions through an observational methodology of data collection. Task performance evaluation was based on detailed measurement of all containers handled, an activity and time analysis, and the 'Work Practices Guide to Manual Lifting’ (NIOSH, 1981) which was used as the primary guide to developing theoretical recommendations to probable MMH risk factors for the workers involved. Of the 191 tasks analysed 103 were deemed unsuitable. Appropriate task factor adjustments were made where necessary to both the frequency and Hfactors (horizontal distance between the centre of gravity of the container and that of the worker) in order to reduce the risk factor for the workers
- Full Text:
- Date Issued: 1989
Investigations into the ecology of a population of Citrus Red Scale (Aonidiella aurantii Mask.) in the Swaziland lowlands
- Authors: Atkinson, P R
- Date: 1982
- Subjects: Citrus -- Diseases and pests -- Africa, Southern
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5619 , http://hdl.handle.net/10962/d1003733
- Description: In the Swaziland lowlands, biological control of the citrus pest red scale, Aonidiella aurantii (Mask), has been consistently unsuccessful although it is successful in middle altitude regions. However, recent cases of resistance to organophosphate insecticides elsewhere in southern Africa, make it important to reconsider biological control of red scale in the lowlands. Should similar resistance be evolved in this region, the pest could be controlled only by natural means together with oils. This account attempts to answer questions about the natural control of a red scale population in the lowlands, by examining data collected between 1972 and 1975. The population was continuously breeding with overlapped generations. It consisted of three sections, on leaves, twigs and fruit, having different rates of reproduction, development and mortality. These sections are considered separately but that on leaves, being relatively unimportant, is largely ignored. The generation mortality is estimated in the sections on twigs and fruit and related to climatic and biotic indices. The causes of seasonal and between-years variation in the sections on twigs and fruit are elucidated. The effectiveness of each kind of natural enemy is examined and the factors affecting natural enemy numbers are investigated. The question of population regulation is discussed. Differences in mean infestation levels in middle altitude and lowland regions are explained in terms of different rates of reproduction and mortality.
- Full Text:
- Date Issued: 1982
- Authors: Atkinson, P R
- Date: 1982
- Subjects: Citrus -- Diseases and pests -- Africa, Southern
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5619 , http://hdl.handle.net/10962/d1003733
- Description: In the Swaziland lowlands, biological control of the citrus pest red scale, Aonidiella aurantii (Mask), has been consistently unsuccessful although it is successful in middle altitude regions. However, recent cases of resistance to organophosphate insecticides elsewhere in southern Africa, make it important to reconsider biological control of red scale in the lowlands. Should similar resistance be evolved in this region, the pest could be controlled only by natural means together with oils. This account attempts to answer questions about the natural control of a red scale population in the lowlands, by examining data collected between 1972 and 1975. The population was continuously breeding with overlapped generations. It consisted of three sections, on leaves, twigs and fruit, having different rates of reproduction, development and mortality. These sections are considered separately but that on leaves, being relatively unimportant, is largely ignored. The generation mortality is estimated in the sections on twigs and fruit and related to climatic and biotic indices. The causes of seasonal and between-years variation in the sections on twigs and fruit are elucidated. The effectiveness of each kind of natural enemy is examined and the factors affecting natural enemy numbers are investigated. The question of population regulation is discussed. Differences in mean infestation levels in middle altitude and lowland regions are explained in terms of different rates of reproduction and mortality.
- Full Text:
- Date Issued: 1982
The extrusive and intrusive basaltic rocks of the Molteno-Jamestown area
- Authors: Mitchell, Andrew Alexander
- Date: 1980
- Subjects: Basalt -- South Africa -- Cape of Good Hope
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4900 , http://hdl.handle.net/10962/d1001559
- Description: The Karoo basalt outliers between Molteno and Jamestown in the north-eastern Cape Province are associated with two central volcanic vent complexes, referred to in the text as the Brosterlea and the Modderfontein complexes. The basalts, particularly those associated with the Brosterlea complex, show geochemical variations throughout the sequence, a factor which has facilitated the subdivision of the Brosterlea basalts into a series of discrete units, each having its own chemical characteristics. Most of the basalt units at Brosterlea can be correlated with units identified in the Barkly East basalt suite. As is the case around Barkly East, the Brosterlea basalt units cannot be related to one another by any simple crystal fractionation or partial melting process, and the most feasible alternative explanation lies in the existence of inhomogeneities in the upper mantle at the time of generation of the magmas. New electron microprobe data are presented for the silicate phases in the Karoo basalts. Analyses of augites from a limited number of slides indicate that pyroxenes from different basalt units define different trends on the Ca - Mg - Fe triangular diagram. The plagioclases in the Brosterlea basalts are fairly Ca-rich (average 70% An), and the K-content of the plagioclases is shown to vary with the K-content of the parent basalt. A comparison of the Karoo Central Province with the younger Columbia River and Deccan Trap Provinces shows many similarities in the evolutionary history of the three provinces. The Karoo Province, however, is distinct from the other two provinces in some aspects of the geochemistry. Broadly speaking, the Karoo basalts are depleted in the incompatible elements relative to the Columbia River and Deccan basalts, and often enriched in the transition metals, most specifically Cr
- Full Text:
- Date Issued: 1980
- Authors: Mitchell, Andrew Alexander
- Date: 1980
- Subjects: Basalt -- South Africa -- Cape of Good Hope
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4900 , http://hdl.handle.net/10962/d1001559
- Description: The Karoo basalt outliers between Molteno and Jamestown in the north-eastern Cape Province are associated with two central volcanic vent complexes, referred to in the text as the Brosterlea and the Modderfontein complexes. The basalts, particularly those associated with the Brosterlea complex, show geochemical variations throughout the sequence, a factor which has facilitated the subdivision of the Brosterlea basalts into a series of discrete units, each having its own chemical characteristics. Most of the basalt units at Brosterlea can be correlated with units identified in the Barkly East basalt suite. As is the case around Barkly East, the Brosterlea basalt units cannot be related to one another by any simple crystal fractionation or partial melting process, and the most feasible alternative explanation lies in the existence of inhomogeneities in the upper mantle at the time of generation of the magmas. New electron microprobe data are presented for the silicate phases in the Karoo basalts. Analyses of augites from a limited number of slides indicate that pyroxenes from different basalt units define different trends on the Ca - Mg - Fe triangular diagram. The plagioclases in the Brosterlea basalts are fairly Ca-rich (average 70% An), and the K-content of the plagioclases is shown to vary with the K-content of the parent basalt. A comparison of the Karoo Central Province with the younger Columbia River and Deccan Trap Provinces shows many similarities in the evolutionary history of the three provinces. The Karoo Province, however, is distinct from the other two provinces in some aspects of the geochemistry. Broadly speaking, the Karoo basalts are depleted in the incompatible elements relative to the Columbia River and Deccan basalts, and often enriched in the transition metals, most specifically Cr
- Full Text:
- Date Issued: 1980
Genetic and bacteriophage studies on Bacteroides thetaiotaomicron and related anaerobic strains
- Authors: Burt, Sharon Joy
- Date: 1978
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:20972 , http://hdl.handle.net/10962/5753
- Description: Gram-negative obligately anaerobic bacilli were isolated from faeces on selective media. R plasmid transfer was investigated in mating experiments between 30 anaerobes and between the anaerobes and known donor and recipient E. coli strains. The transfer of R plasmids from E.coli to B.fragilis, Bacteroides spp., Fusobacterium spp. and other faecal obligate anaerobic bacteria was possible after heat treatment of the recipients at 50°C. The anaerobic exconjugants were unstable and were not able to retransfer the ampr marker. A bacteriophage, B1 , specific for the anaerobe B.thetaiotaomicron, was isolated and characterised. The properties of the phage included a variable burst size and the production of many defective phage particles without tails which were not viable. The B.thetaiotaomicron host was able to establish a phage carrier state with B1 phage. Phenol-extracted phage DNA could transfect ca2+-treated B.thetaiotaomicron cells and transfection was not limited to a particular stage in the growth cycle. An obligatory step in the transfection procedure was a 33-fold dilution in broth, allowing replication of the infected cells. Prolonged incubation of treated cells with DNA prior to dilution in broth resulted in a large decrease in phage titre. The application of this transfection system to the development of a transformation system was not successful . Conventional transformation procedures did not yield transformants, and it was not possible to transduce B.thetaiotaomicron with B1 phage. The B.thetaiotaomicron strain used was distinguished by the formation of two distinct morphological variants. Each morphological type gave rise to the other at the same frequency. Environmental conditions other than elevated temperature, had no effect on the segregation frequency. The grey colony variant was not capsulated and was sensitive to B1 phage, whereas the white colony type was encapsulated and was phage-resistant. Another feature of the B.thetaiotaomicron strain was the low incidence of mutants. A second survey of the occurrence of R plasmids in aerobic coliforms from a remote area of the Transkei and from an urban area, was undertaken. An increase in transferable antibiotic resistance was found over the last three years. It can be concluded that this was a result of the use of antibiotics among the human population, since there are no veterinary services in the area and the addition of antibiotics to animal feeds is not practised.
- Full Text:
- Date Issued: 1978
- Authors: Burt, Sharon Joy
- Date: 1978
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:20972 , http://hdl.handle.net/10962/5753
- Description: Gram-negative obligately anaerobic bacilli were isolated from faeces on selective media. R plasmid transfer was investigated in mating experiments between 30 anaerobes and between the anaerobes and known donor and recipient E. coli strains. The transfer of R plasmids from E.coli to B.fragilis, Bacteroides spp., Fusobacterium spp. and other faecal obligate anaerobic bacteria was possible after heat treatment of the recipients at 50°C. The anaerobic exconjugants were unstable and were not able to retransfer the ampr marker. A bacteriophage, B1 , specific for the anaerobe B.thetaiotaomicron, was isolated and characterised. The properties of the phage included a variable burst size and the production of many defective phage particles without tails which were not viable. The B.thetaiotaomicron host was able to establish a phage carrier state with B1 phage. Phenol-extracted phage DNA could transfect ca2+-treated B.thetaiotaomicron cells and transfection was not limited to a particular stage in the growth cycle. An obligatory step in the transfection procedure was a 33-fold dilution in broth, allowing replication of the infected cells. Prolonged incubation of treated cells with DNA prior to dilution in broth resulted in a large decrease in phage titre. The application of this transfection system to the development of a transformation system was not successful . Conventional transformation procedures did not yield transformants, and it was not possible to transduce B.thetaiotaomicron with B1 phage. The B.thetaiotaomicron strain used was distinguished by the formation of two distinct morphological variants. Each morphological type gave rise to the other at the same frequency. Environmental conditions other than elevated temperature, had no effect on the segregation frequency. The grey colony variant was not capsulated and was sensitive to B1 phage, whereas the white colony type was encapsulated and was phage-resistant. Another feature of the B.thetaiotaomicron strain was the low incidence of mutants. A second survey of the occurrence of R plasmids in aerobic coliforms from a remote area of the Transkei and from an urban area, was undertaken. An increase in transferable antibiotic resistance was found over the last three years. It can be concluded that this was a result of the use of antibiotics among the human population, since there are no veterinary services in the area and the addition of antibiotics to animal feeds is not practised.
- Full Text:
- Date Issued: 1978
Interactions between steroidal anti-inflammatory agents and collagen
- Authors: Kanfer, Isadore
- Date: 1975
- Subjects: Anti-inflammatory agents Collagen
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3849 , http://hdl.handle.net/10962/d1012620
- Description: Much research has been done on the formation of fibrils from solutions of soluble collagen in vitro in order to gain some knowledge of the mechanisms which may occur in vivo. The in vitro formation of fibres from solutions of collagen has been shown to be extremely sensitive to the nature of the solution environment and the presence of added chemical compounds, and thus constitutes an interesting system for the study of collagen-small molecule inter actions. The present study is concerned with the effects of various corticosteroid drugs, used medicinally as anti-inflammatory agents, on collagen in solution. As these corticosteroids are administered to reduce inflammation in conditions such as rheumatoid arthritis and a host of other pathological conditions in which collagen is implicated, this work has been undertaken in order to establish and charac teri ze any binding mechanisms which may be involved. Furthermore, the corticosteroid drugs available commercially in pure form as the free base or as the water-soluble ester salts offer an interesting range of structural and stereochemical variants for the study of their reaction with a complex and biologically important protein molecule such as collagen. A great deal of research on drug- protein interactions (Goldstein, 1949; Meyer and Guttman, 1968a) and more specifically, steroid-protein interactions have been reported over the years (Daughaday, 1959; Sandberg et al., 1966; Villee and Engel, 1961; Westphal , 1971). Comprehensive reports, however, on steroid-collagen interactions in vitro are conspicuously absent from modern scientific literature although relatively superficial accounts have been published (Menczel and Maibach, 1972; Eik-Nes et al., 1954). Although work involving the above has appeared relating specifically to the effects of steroids on collagen biosynthesis both in vivo and in vitro there have been minimal accounts of steroid-collagen interactions tailored to characterize the binding at the molecular level. The effect of corticosteroids on the metabolism of connective tissue has also received special attention (Asboe-Hansen, 1959; Kivirikko, 1953; Nakagawa and Tsurufuji, 1972). Recently, Uitto et al. (1972) reported the effects of several anti-inflammatory corticosteroids on collagen biosynthesis in vitro, whilst Aalto and Kulonen (1972) reported the effects of several antirheumatic drugs on the synthesis of collagen and other proteins in vitro. The interactions between collagen and certain drugs has also been briefly reviewed (Chvapil, 1967). Much data also exists on the binding of a wide range of small molecules and ions with serum albumin (Steinhardt and Reynolds, 1969; Scatchard, 1949; Klotz, 1950). Serum albumin, being specialized for a very general transport function and apparently designed for the purpose of combining with a large range of small molecules, has a proportion of possible reactive sites 'buried' within the molecule itself because of its folded conformation. In addition, serum albumin shows a high degree of cooperative binding in contrast to collagen. The latter molecule, with its larger molecular size and weight is specialized for a biologically structural function and has a higher proportion of possible reactive sites which appear relatively more accessible to ligands. A study of the interactions between corticosteroids and collagen thus provides the opportunity to investigate a protein which is very different from the much studied serum albumin. Because of the limited information available regarding the interaction of steroid drugs and collagen at the molecular level, studies of this nature are relevant to the understanding of the mode of action of steroid compounds which are such an important group of therapeutic substances used in modern medicine.
- Full Text:
- Date Issued: 1975
- Authors: Kanfer, Isadore
- Date: 1975
- Subjects: Anti-inflammatory agents Collagen
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3849 , http://hdl.handle.net/10962/d1012620
- Description: Much research has been done on the formation of fibrils from solutions of soluble collagen in vitro in order to gain some knowledge of the mechanisms which may occur in vivo. The in vitro formation of fibres from solutions of collagen has been shown to be extremely sensitive to the nature of the solution environment and the presence of added chemical compounds, and thus constitutes an interesting system for the study of collagen-small molecule inter actions. The present study is concerned with the effects of various corticosteroid drugs, used medicinally as anti-inflammatory agents, on collagen in solution. As these corticosteroids are administered to reduce inflammation in conditions such as rheumatoid arthritis and a host of other pathological conditions in which collagen is implicated, this work has been undertaken in order to establish and charac teri ze any binding mechanisms which may be involved. Furthermore, the corticosteroid drugs available commercially in pure form as the free base or as the water-soluble ester salts offer an interesting range of structural and stereochemical variants for the study of their reaction with a complex and biologically important protein molecule such as collagen. A great deal of research on drug- protein interactions (Goldstein, 1949; Meyer and Guttman, 1968a) and more specifically, steroid-protein interactions have been reported over the years (Daughaday, 1959; Sandberg et al., 1966; Villee and Engel, 1961; Westphal , 1971). Comprehensive reports, however, on steroid-collagen interactions in vitro are conspicuously absent from modern scientific literature although relatively superficial accounts have been published (Menczel and Maibach, 1972; Eik-Nes et al., 1954). Although work involving the above has appeared relating specifically to the effects of steroids on collagen biosynthesis both in vivo and in vitro there have been minimal accounts of steroid-collagen interactions tailored to characterize the binding at the molecular level. The effect of corticosteroids on the metabolism of connective tissue has also received special attention (Asboe-Hansen, 1959; Kivirikko, 1953; Nakagawa and Tsurufuji, 1972). Recently, Uitto et al. (1972) reported the effects of several anti-inflammatory corticosteroids on collagen biosynthesis in vitro, whilst Aalto and Kulonen (1972) reported the effects of several antirheumatic drugs on the synthesis of collagen and other proteins in vitro. The interactions between collagen and certain drugs has also been briefly reviewed (Chvapil, 1967). Much data also exists on the binding of a wide range of small molecules and ions with serum albumin (Steinhardt and Reynolds, 1969; Scatchard, 1949; Klotz, 1950). Serum albumin, being specialized for a very general transport function and apparently designed for the purpose of combining with a large range of small molecules, has a proportion of possible reactive sites 'buried' within the molecule itself because of its folded conformation. In addition, serum albumin shows a high degree of cooperative binding in contrast to collagen. The latter molecule, with its larger molecular size and weight is specialized for a biologically structural function and has a higher proportion of possible reactive sites which appear relatively more accessible to ligands. A study of the interactions between corticosteroids and collagen thus provides the opportunity to investigate a protein which is very different from the much studied serum albumin. Because of the limited information available regarding the interaction of steroid drugs and collagen at the molecular level, studies of this nature are relevant to the understanding of the mode of action of steroid compounds which are such an important group of therapeutic substances used in modern medicine.
- Full Text:
- Date Issued: 1975
The population dynamics of an indigenous Psyllid Acizzia Russellae (Homoptera: Psyllidae )with special reference to the influence of the host plant Acacia Karroo
- Authors: Webb, John Warren
- Date: 1975
- Subjects: Homoptera , Jumping plant-lice , Insect populations , Insects -- Ecology , Acacia -- Karroo
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5894 , http://hdl.handle.net/10962/d1013415
- Description: The biology and ecology of an indigenous, non-pest insect on an indigenous host plant were investigated. The study includes a taxonomic description of this new species, an account of its general biology, monitoring of the seasonal fluctuations in numbers of the psyllid and its hymenopterous parasitoids, and a study of various aspects of the host plant, including nitrogen levels, water stress, leaf hardness, and the effect of cutting, in relation to spatial and temporal differences in insect population numbers. Natural enemies, inter- and intra-specific competition had very little determining influence on the population numbers of the psyllid. Temperature and humidity had little direct effect, but may have influenced the population dynamics via its effects on the host plant. Seasonal patterns in psyllid numbers followed fluctuations in nitrogen levels; statistically valid correlations were obtained between leaf nitrogen and psyllid numbers on individual trees at various times. These findings were supported by the results of preliminary laboratory experiments employing different fertilizer treatments. No effect of water stress or leaf hardness was clearly discerned. Cutting of trees altered the characteristics of the subsequent regenerative growth so as to allow massive psyllid infestations to develop, thus showing the tremendous importance of the host plant in determining population levels in this insect. Preliminary investigations of the nature and mechanism of this effect were conducted, and its significance is discussed. The relevance of these findings to modern concepts of regulation in insect populations and to principles of pest management is discussed.
- Full Text:
- Date Issued: 1975
- Authors: Webb, John Warren
- Date: 1975
- Subjects: Homoptera , Jumping plant-lice , Insect populations , Insects -- Ecology , Acacia -- Karroo
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5894 , http://hdl.handle.net/10962/d1013415
- Description: The biology and ecology of an indigenous, non-pest insect on an indigenous host plant were investigated. The study includes a taxonomic description of this new species, an account of its general biology, monitoring of the seasonal fluctuations in numbers of the psyllid and its hymenopterous parasitoids, and a study of various aspects of the host plant, including nitrogen levels, water stress, leaf hardness, and the effect of cutting, in relation to spatial and temporal differences in insect population numbers. Natural enemies, inter- and intra-specific competition had very little determining influence on the population numbers of the psyllid. Temperature and humidity had little direct effect, but may have influenced the population dynamics via its effects on the host plant. Seasonal patterns in psyllid numbers followed fluctuations in nitrogen levels; statistically valid correlations were obtained between leaf nitrogen and psyllid numbers on individual trees at various times. These findings were supported by the results of preliminary laboratory experiments employing different fertilizer treatments. No effect of water stress or leaf hardness was clearly discerned. Cutting of trees altered the characteristics of the subsequent regenerative growth so as to allow massive psyllid infestations to develop, thus showing the tremendous importance of the host plant in determining population levels in this insect. Preliminary investigations of the nature and mechanism of this effect were conducted, and its significance is discussed. The relevance of these findings to modern concepts of regulation in insect populations and to principles of pest management is discussed.
- Full Text:
- Date Issued: 1975
An investigation into religious instruction in state high schools in the Cape Province
- Authors: Penny, Alan Joseph
- Date: 1971
- Subjects: Religious education -- South Africa -- Cape of Good Hope Religious education of teenagers
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1933 , http://hdl.handle.net/10962/d1007641
- Description: From Preface: The question of religious instruction in Cape Schools first aroused my interest when I was subjected to anything but religious tnstruction during my own high school years. My desire to enquire into the whole position of religious instruction in the high school curriculum grew out of an essay on the role of religion in the education of the child which I wrote whilst reading for the B.Ed. degree. As background, I read Harold Loukes' classic Teenage Religion, and from then onwards, I felt that it was necessary to undertake an investigation of this kind in the Cape Province. My aim was not only prompted out of a desire to expose what I already knew to be an educationally and religiously unsound and unhealthy state of affairs, but more deeply because I, although an ignorant amateur in theology, am aware that too often the traditional religious foundations, poorly built by unintelligent teaching, are shaken, if not destroyed, by scientific discovery and material advancement.
- Full Text:
- Date Issued: 1971
- Authors: Penny, Alan Joseph
- Date: 1971
- Subjects: Religious education -- South Africa -- Cape of Good Hope Religious education of teenagers
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1933 , http://hdl.handle.net/10962/d1007641
- Description: From Preface: The question of religious instruction in Cape Schools first aroused my interest when I was subjected to anything but religious tnstruction during my own high school years. My desire to enquire into the whole position of religious instruction in the high school curriculum grew out of an essay on the role of religion in the education of the child which I wrote whilst reading for the B.Ed. degree. As background, I read Harold Loukes' classic Teenage Religion, and from then onwards, I felt that it was necessary to undertake an investigation of this kind in the Cape Province. My aim was not only prompted out of a desire to expose what I already knew to be an educationally and religiously unsound and unhealthy state of affairs, but more deeply because I, although an ignorant amateur in theology, am aware that too often the traditional religious foundations, poorly built by unintelligent teaching, are shaken, if not destroyed, by scientific discovery and material advancement.
- Full Text:
- Date Issued: 1971