Diurnal and nocturnal activity patterns and habitat use of Algoa Bay’s rocky reef fish community
- Authors: Juby, Roxanne
- Date: 2017
- Subjects: Reef fishes -- Effect of light on , Reef fishes -- South Africa , Underwater videography in wildlife monitoring -- South Africa -- Tsitsikamma
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/44827 , vital:25445
- Description: Distinct day-night changes in ambient light are recognised as an important driver of animal activity patterns, with predictable changes to the structure and composition of animal communities between day and night. While day-night variation in the structure of animal communities has been well researched for terrestrial organisms and shallow marine fish communities around the world, there has been limited research of this type conducted on South Africa’s rocky reef fish communities. Consequently, we have a poor understanding of how nocturnal reef fish communities are structured and the day-night activity patterns of species inhabiting both shallow (10-30m) and deep-aphotic (55-100m) reefs. This research was conducted at two warm-temperate South African rocky reefs situated in Algoa Bay. The importance of natural ambient light in shaping the distribution of reef fish communities at shallow and deep-aphotic reef sites was demonstrated using baited remote underwater stereo-video systems (stereo-BRUVs). Distinct day and night fish communities were sampled at shallow and deep-aphotic reef sites. These differences were driven by significant changes in species richness (p < 0.001), species abundance (p < 0.001) and community composition (p < 0.001). These shifts appeared to be driven by day-night activity patterns that were the result of increased detectability of certain species at either day or night. The majority of species belonging to the family Sparidae showed evidence of strict diurnal activity, with their activity being further restricted to shallow reefs. These species showed evidence that they may enter micro-habitats within the reef at night. Similar activity patterns were shown for other top predatory teleost species and low level consumers, with substantial reductions in abundances, or no recordings at night throughout this study. Shallow reefs at day harboured the most diverse fish community. It is therefore hypothesised that this habitat was associated with conditions that offered improved access to resources for many visual species. In addition, the diverse community inhabiting shallow reefs at day is associated with a high risk of negative interspecies interactions, such as competition and predation. It is hypothesised that the biotic conditions associated with shallow reefs at day drove three movement patterns identified in this study; Pagellus bellottii natalensis showed evidence of movement onto shallow reefs at night from adjacent sandy flats, while Pterogymnus laniarius and Squalus sp. 1 showed evidence of movement onto shallow reefs at night from the deep- aphotic reefs that remain dark throughout the diel cycle. It is further hypothesised that other species which showed evidence for nocturnal activity, i.e. Galeichthys ater, Eptatretus hexatrema and Haploblepharus edwardsii, may enter sheltered micro-habitats within the reef during day light hours. These findings have highlighted the complex patterns that have evolved within marine fish to allow multiple species to coexist and exploit productive reef ecosystems by partitioning resource use and activity patterns at day or night, between depth zones and habitat types.
- Full Text:
- Date Issued: 2017
- Authors: Juby, Roxanne
- Date: 2017
- Subjects: Reef fishes -- Effect of light on , Reef fishes -- South Africa , Underwater videography in wildlife monitoring -- South Africa -- Tsitsikamma
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/44827 , vital:25445
- Description: Distinct day-night changes in ambient light are recognised as an important driver of animal activity patterns, with predictable changes to the structure and composition of animal communities between day and night. While day-night variation in the structure of animal communities has been well researched for terrestrial organisms and shallow marine fish communities around the world, there has been limited research of this type conducted on South Africa’s rocky reef fish communities. Consequently, we have a poor understanding of how nocturnal reef fish communities are structured and the day-night activity patterns of species inhabiting both shallow (10-30m) and deep-aphotic (55-100m) reefs. This research was conducted at two warm-temperate South African rocky reefs situated in Algoa Bay. The importance of natural ambient light in shaping the distribution of reef fish communities at shallow and deep-aphotic reef sites was demonstrated using baited remote underwater stereo-video systems (stereo-BRUVs). Distinct day and night fish communities were sampled at shallow and deep-aphotic reef sites. These differences were driven by significant changes in species richness (p < 0.001), species abundance (p < 0.001) and community composition (p < 0.001). These shifts appeared to be driven by day-night activity patterns that were the result of increased detectability of certain species at either day or night. The majority of species belonging to the family Sparidae showed evidence of strict diurnal activity, with their activity being further restricted to shallow reefs. These species showed evidence that they may enter micro-habitats within the reef at night. Similar activity patterns were shown for other top predatory teleost species and low level consumers, with substantial reductions in abundances, or no recordings at night throughout this study. Shallow reefs at day harboured the most diverse fish community. It is therefore hypothesised that this habitat was associated with conditions that offered improved access to resources for many visual species. In addition, the diverse community inhabiting shallow reefs at day is associated with a high risk of negative interspecies interactions, such as competition and predation. It is hypothesised that the biotic conditions associated with shallow reefs at day drove three movement patterns identified in this study; Pagellus bellottii natalensis showed evidence of movement onto shallow reefs at night from adjacent sandy flats, while Pterogymnus laniarius and Squalus sp. 1 showed evidence of movement onto shallow reefs at night from the deep- aphotic reefs that remain dark throughout the diel cycle. It is further hypothesised that other species which showed evidence for nocturnal activity, i.e. Galeichthys ater, Eptatretus hexatrema and Haploblepharus edwardsii, may enter sheltered micro-habitats within the reef during day light hours. These findings have highlighted the complex patterns that have evolved within marine fish to allow multiple species to coexist and exploit productive reef ecosystems by partitioning resource use and activity patterns at day or night, between depth zones and habitat types.
- Full Text:
- Date Issued: 2017
Drawing on principles of Dance Movement Therapy practice in a South African water research context
- Authors: Copteros, Athina
- Date: 2017
- Subjects: Water-supply -- Management -- South Africa , Dance therapy , Movement therapy , Dance therapy -- South Africa , Movement therapy -- South Africa , Interdisciplinary research , Interdisciplinary approach to knowledge , Environmental education , Environmental education -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/50759 , vital:26024
- Description: Research that draws on principles of Dance Movement Therapy in a South African water research context has not been done before. In order to initiate this exploration, culturally relevant themes from professional training in the United Kingdom were identified that could be developed in the context of trans-disciplinary water resource management research in South Africa. Hermeneutic phenomenology provided the methodological framing for this study. Interpretative Phenomenological Analysis was used to discover culturally relevant themes based on the recorded perceptions of the phenomenon of the training while it was taking place. The themes of: ‘awareness of power and difference'; ‘therapeutic adaptability'; ‘safety and ownership' and ‘connecting with the environment' emerged as overriding themes. Influences from Artistic Inquiry informed the inclusion of a creative embodied response to the themes that emerged. These themes then informed the application of some relevant principles of Dance Movement Therapy practice within a trans-disciplinary complex social-ecological systems researcher group. Eight members of the group participated in the study. They represented a range of academic research roles, genders and backgrounds. They reflected on their experience of an introductory session and five Dance Movement Therapy based sessions in semi-structured interviews. Using Interpretative Phenomenological Analysis, four themes were identified that capture the quality of the participants' shared experience of the phenomenon: ‘community engagement'; ‘embodiment'; ‘individual and group identity' and ‘integration'. Based on the integration of themes, it is concluded that principles of Dance Movement Therapy have a contribution to make. Core tenets of Dance Movement Therapy such as: inclusion of body and emotion; healing from trauma through embodiment; group processes held with safety and acceptance; and a deep level of connection to self, each other and the wider ecology, address some of the basic challenges of trans-disciplinary complex social ecological systems research practice. Through researchers experiencing principles of DMT practice for themselves and reflecting on their experience, it is possible that their embodied knowledge and reflections will influence and inform their engagement with communities in the future.
- Full Text:
- Date Issued: 2017
- Authors: Copteros, Athina
- Date: 2017
- Subjects: Water-supply -- Management -- South Africa , Dance therapy , Movement therapy , Dance therapy -- South Africa , Movement therapy -- South Africa , Interdisciplinary research , Interdisciplinary approach to knowledge , Environmental education , Environmental education -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/50759 , vital:26024
- Description: Research that draws on principles of Dance Movement Therapy in a South African water research context has not been done before. In order to initiate this exploration, culturally relevant themes from professional training in the United Kingdom were identified that could be developed in the context of trans-disciplinary water resource management research in South Africa. Hermeneutic phenomenology provided the methodological framing for this study. Interpretative Phenomenological Analysis was used to discover culturally relevant themes based on the recorded perceptions of the phenomenon of the training while it was taking place. The themes of: ‘awareness of power and difference'; ‘therapeutic adaptability'; ‘safety and ownership' and ‘connecting with the environment' emerged as overriding themes. Influences from Artistic Inquiry informed the inclusion of a creative embodied response to the themes that emerged. These themes then informed the application of some relevant principles of Dance Movement Therapy practice within a trans-disciplinary complex social-ecological systems researcher group. Eight members of the group participated in the study. They represented a range of academic research roles, genders and backgrounds. They reflected on their experience of an introductory session and five Dance Movement Therapy based sessions in semi-structured interviews. Using Interpretative Phenomenological Analysis, four themes were identified that capture the quality of the participants' shared experience of the phenomenon: ‘community engagement'; ‘embodiment'; ‘individual and group identity' and ‘integration'. Based on the integration of themes, it is concluded that principles of Dance Movement Therapy have a contribution to make. Core tenets of Dance Movement Therapy such as: inclusion of body and emotion; healing from trauma through embodiment; group processes held with safety and acceptance; and a deep level of connection to self, each other and the wider ecology, address some of the basic challenges of trans-disciplinary complex social ecological systems research practice. Through researchers experiencing principles of DMT practice for themselves and reflecting on their experience, it is possible that their embodied knowledge and reflections will influence and inform their engagement with communities in the future.
- Full Text:
- Date Issued: 2017
Drivers of sustainability disclosure in Liberty Holdings
- Authors: Chembeya, Edina Matamba
- Date: 2017
- Subjects: Liberty Holdings Limited (Firm) , Insurance companies -- South Africa -- Management , Risk management -- South Africa -- Case studies , Stakeholder management -- South Africa -- Case studies , Corporate culture -- South Africa -- Case studies , Product management -- South Africa -- Case studies
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: http://hdl.handle.net/10962/5579 , vital:20943
- Description: This research assesses the drivers of sustainability disclosure in Liberty Holdings. The relevance of reporting on sustainability is growing for both listed and non-listed companies in South Africa. However, many companies many companies still coming to terms with reporting process, although others are doing exceptionally well. Liberty Holdings is one of the insurance organisations that has continuously improved their sustainability reporting and disclosure of their sustainability issues, in a sector that previously perceived such concerns as low on their agenda, due to the perception that they had a low impact on the sector. The research findings reveal that the process of sustainability disclosure in Liberty Holdings is driven by several elements that are strategically linked and are aligned to the core strategy of the organisation. The findings also indicate that in order to understand and implement viable sustainability processes, the processes must be embedded in a well-informed sustainability strategy that is aligned with this core strategy.
- Full Text:
- Date Issued: 2017
- Authors: Chembeya, Edina Matamba
- Date: 2017
- Subjects: Liberty Holdings Limited (Firm) , Insurance companies -- South Africa -- Management , Risk management -- South Africa -- Case studies , Stakeholder management -- South Africa -- Case studies , Corporate culture -- South Africa -- Case studies , Product management -- South Africa -- Case studies
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: http://hdl.handle.net/10962/5579 , vital:20943
- Description: This research assesses the drivers of sustainability disclosure in Liberty Holdings. The relevance of reporting on sustainability is growing for both listed and non-listed companies in South Africa. However, many companies many companies still coming to terms with reporting process, although others are doing exceptionally well. Liberty Holdings is one of the insurance organisations that has continuously improved their sustainability reporting and disclosure of their sustainability issues, in a sector that previously perceived such concerns as low on their agenda, due to the perception that they had a low impact on the sector. The research findings reveal that the process of sustainability disclosure in Liberty Holdings is driven by several elements that are strategically linked and are aligned to the core strategy of the organisation. The findings also indicate that in order to understand and implement viable sustainability processes, the processes must be embedded in a well-informed sustainability strategy that is aligned with this core strategy.
- Full Text:
- Date Issued: 2017
Early stage ichthyofauna from shallow water habitats of the Angola-Benguela frontal zone
- Authors: Farthing, Matthew William
- Date: 2017
- Subjects: Fishes -- Larvae -- South Africa -- Atlantic coast , Fishes -- Larvae -- Angola -- Atlantic coast , Striped mullet -- Angola -- Atlantic coast
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/50442 , vital:25988
- Description: Early stage fishes (larvae and early juveniles) were collected from an array of shallow water (±1.5m) habitats on the warm-temperate southern Angolan coastline between June 2014 and June 2015. This study, the first assessment of the early stages of coastal fishes in Angola, provides important new understanding of non-estuarine shallow water nursery habitat use by coastal fishes from the region. In total, 51 species from 18 teleost families were observed. The exposed surf zone was dominated by postflexion larvae, while the moderately exposed beach and sheltered bay were dominated by early juveniles. Both fish density and diversity peaked in the wet season (Feb – Apr 2015) for all habitats, attributed to the influx of summer spawning species. Diplodus sargus dominated catches from the exposed surf zone, and the timing of observations supports the growing consensus that sparid spawning is dictated by temperature, not season. The similitude of the observed species to those observed in warm temperate South Africa highlights the historical connection of the warm-temperate study area with warm-temperate South Africa, prior to the formation of the Benguela Current as a vicariant barrier. The classification of the study assemblage into established estuarine utilization categories showed that the surf zone hosted more exclusively marine species than comparable surf zones in South Africa, attributed to the absence of estuaries in southern Angola. However, the observation of the marine estuarine dependent Mugil cephalus in this study area devoid of estuaries suggests that estuarine dependency may be regionally specific for some taxa. It appears that the warm, sheltered, nutrient rich waters of Tombua Bay provide typically estuarine associated taxa with a suitable alternative, non-estuarine nursery habitat. This study provides evidence that the importance of estuaries as critical nursery habitats has been overemphasized for some warm-temperate coastal fishes. However, the absence of other marine estuarine dependent species from the study area suggests that some warm-temperate taxa do intrinsically rely on estuarine function for survival.
- Full Text:
- Date Issued: 2017
- Authors: Farthing, Matthew William
- Date: 2017
- Subjects: Fishes -- Larvae -- South Africa -- Atlantic coast , Fishes -- Larvae -- Angola -- Atlantic coast , Striped mullet -- Angola -- Atlantic coast
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/50442 , vital:25988
- Description: Early stage fishes (larvae and early juveniles) were collected from an array of shallow water (±1.5m) habitats on the warm-temperate southern Angolan coastline between June 2014 and June 2015. This study, the first assessment of the early stages of coastal fishes in Angola, provides important new understanding of non-estuarine shallow water nursery habitat use by coastal fishes from the region. In total, 51 species from 18 teleost families were observed. The exposed surf zone was dominated by postflexion larvae, while the moderately exposed beach and sheltered bay were dominated by early juveniles. Both fish density and diversity peaked in the wet season (Feb – Apr 2015) for all habitats, attributed to the influx of summer spawning species. Diplodus sargus dominated catches from the exposed surf zone, and the timing of observations supports the growing consensus that sparid spawning is dictated by temperature, not season. The similitude of the observed species to those observed in warm temperate South Africa highlights the historical connection of the warm-temperate study area with warm-temperate South Africa, prior to the formation of the Benguela Current as a vicariant barrier. The classification of the study assemblage into established estuarine utilization categories showed that the surf zone hosted more exclusively marine species than comparable surf zones in South Africa, attributed to the absence of estuaries in southern Angola. However, the observation of the marine estuarine dependent Mugil cephalus in this study area devoid of estuaries suggests that estuarine dependency may be regionally specific for some taxa. It appears that the warm, sheltered, nutrient rich waters of Tombua Bay provide typically estuarine associated taxa with a suitable alternative, non-estuarine nursery habitat. This study provides evidence that the importance of estuaries as critical nursery habitats has been overemphasized for some warm-temperate coastal fishes. However, the absence of other marine estuarine dependent species from the study area suggests that some warm-temperate taxa do intrinsically rely on estuarine function for survival.
- Full Text:
- Date Issued: 2017
Ecosystem engineering by the wetland plant palmiet: does it control fluvial form and promote diffuse flow in steep-sided valleys of the Cape Fold Mountains
- Authors: Barclay, Amy
- Date: 2017
- Subjects: Prionium serratum , Wetlands -- South Africa -- Eastern Cape , Aquatic plants -- South Africa -- Eastern Cape , Peatland ecology -- South Africa -- Eastern Cape , Kromme River (Eastern Cape, South Africa)
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/4646 , vital:20708
- Description: Ecosystem engineering refers to the way that organisms control the structure and function of ecosystems. It has been suggested that palmiet (Prionium serratum, Thurniaceae) works as an ecosystem engineer, shaping peat wetlands in South Africa. However, there is currently a paucity of evidence supporting this claim. Palmiet has a dense root, rhizome and stem system that forms dense stands, growing from channel banks into fast flowing river channels. This slows river flows, traps sediment, which builds up riverbeds and ultimately blocks river channels, turning the river into a wetland. The aim of this study was to determine if palmiet is an ecosystem engineer and to document its pattern of colonisation and the nature of its control of a fluvial system. This was achieved by undertaking vegetation surveys in the Kromrivier Wetland in the Eastern Cape. The data was analyzed using vegetation classification and ordination, where vegetation communities were linked to environmental factors. It was found that palmiet occupied three distinctive habitats; 1) on near-horizontal valley- bottom habitats filled with sediments that are a mixture of autochthonous organic sediment and allochthonous clastic fines, 2) the bed of gullies that have recently filled with coarse grained clastic sediment, and 3) open water bodies. Three conceptual models were developed, one that accounts for the process of gully bed colonisation, sediment trapping and gully filling, another involving rapid colonisation of sedimentary fill from tributary sediment sources that block a gully, and the third involving colonisation of open-water areas that form in former gullies upstream of the blockage. The study suggests that the wetland has been characterised by repeated cutting and filling cycles, despite which, palmiet has repeatedly reinstated diffuse flow conditions across the valley floor. Palmiet was indicated to exert a key control on fluvial form and dynamics of the wetlands in the Kromrivier valley.
- Full Text:
- Date Issued: 2017
- Authors: Barclay, Amy
- Date: 2017
- Subjects: Prionium serratum , Wetlands -- South Africa -- Eastern Cape , Aquatic plants -- South Africa -- Eastern Cape , Peatland ecology -- South Africa -- Eastern Cape , Kromme River (Eastern Cape, South Africa)
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/4646 , vital:20708
- Description: Ecosystem engineering refers to the way that organisms control the structure and function of ecosystems. It has been suggested that palmiet (Prionium serratum, Thurniaceae) works as an ecosystem engineer, shaping peat wetlands in South Africa. However, there is currently a paucity of evidence supporting this claim. Palmiet has a dense root, rhizome and stem system that forms dense stands, growing from channel banks into fast flowing river channels. This slows river flows, traps sediment, which builds up riverbeds and ultimately blocks river channels, turning the river into a wetland. The aim of this study was to determine if palmiet is an ecosystem engineer and to document its pattern of colonisation and the nature of its control of a fluvial system. This was achieved by undertaking vegetation surveys in the Kromrivier Wetland in the Eastern Cape. The data was analyzed using vegetation classification and ordination, where vegetation communities were linked to environmental factors. It was found that palmiet occupied three distinctive habitats; 1) on near-horizontal valley- bottom habitats filled with sediments that are a mixture of autochthonous organic sediment and allochthonous clastic fines, 2) the bed of gullies that have recently filled with coarse grained clastic sediment, and 3) open water bodies. Three conceptual models were developed, one that accounts for the process of gully bed colonisation, sediment trapping and gully filling, another involving rapid colonisation of sedimentary fill from tributary sediment sources that block a gully, and the third involving colonisation of open-water areas that form in former gullies upstream of the blockage. The study suggests that the wetland has been characterised by repeated cutting and filling cycles, despite which, palmiet has repeatedly reinstated diffuse flow conditions across the valley floor. Palmiet was indicated to exert a key control on fluvial form and dynamics of the wetlands in the Kromrivier valley.
- Full Text:
- Date Issued: 2017
Ecosystem services in a biosphere reserve context: identification, mapping and valuation
- Authors: Ntshane, Basane Claire
- Date: 2017
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/4536 , vital:20686
- Description: Despite their contribution to human well-being, ecosystem services (ES) are being destroyed by anthropogenic activities, taken for granted and often compromised during land use decision making. The question that often arises is, what value do ES have compared to other undertakings that are economically robust, such as mining? The vision of the Millenium Ecosystem Assessment (MA) was a world in which natural assets (including ES) are appreciated and integrated into decision-making. The biodiversity strategy of the Convention on Biological Diversity (CBD) also concerns the integration of natural assets into decision making. Responding to challenges facing ES and their mainstreaming into decision-making has been constrained by lack of data and requires new tools and approaches. Integrating natural assets into decision-making is very important for South Africa (SA), where ES have been a crucial part of human systems for decades, and also because of the country’s commitment to the implementation of the CBD's biodiversity strategy. With the aim of incorporating ES into decision-making in an integrated way, this study was conducted in two biosphere reserves (BRs), Vhembe and Waterberg, in Limpopo Province, SA. The aims of the study were the identification, mapping and valuation of ES following an integrated approach. In order to achieve these aims, the study attempted to address four key objectives: (1) to assess and evaluate the status of mapping and valuation of ES in SA, (2) to identify and quantify ES and their indicators, (3) to investigate and analyse the impact of land use/cover (LU/LC) change to ES and (4) to conduct valuation of selected ES. Two separate literature reviews were undertaken to assess and evaluate the status of mapping and valuation of ES in SA, thus addressing study objective 1. Both reviews detected a significant research gap with regard to mapping and valuation of supporting services in SA. To identify ES and indicators provided by the two BRs and to assess the impact of LU/LC change and its effect on ES, a participatory scenario planning process was conducted under three different scenarios, namely ecological development, social development and economic development. It became clear that LU issues were diverse in nature and affected ES in a number of ways and that there were always trade-offs in the choice of LU. For example, yields of ES were best in the ecological development scenario and were affected negatively, together with agricultural commodity production, in the social development and economic development scenarios. A mapping exercise was undertaken to illustrate the spatial distribution of ES supply and demand, involving five ES and 15 indicators using existing datasets and the Integrated Valuation of Ecosystem Services and Trade-offs (InVEST) mapping tool, again addressing objective 2 of the study. Carbon storage and habitat quality were assessed, modelled and quantified and their values provided in biophysical terms using InVEST modelling tools, thus addressing objective 4 of the study. High quantities of carbon storage and high habitat quality were recorded in natural areas and low quantities were recorded in managed systems (cultivated, urban and plantation areas). InVEST was again applied to conduct an economic valuation of two provisioning ES, timber and firewood, by determining their net present values, attempting to address objective 4 of the study. Results revealed that, at 12% discount rate, the net present value (NPV) for timber production accounted for R23 317/ha in VBR and R57 304/ha in WBR. However, at lower discount rates (4 and 7%), the NPVs for timber were negative in VBR and positive in WBR. With regard to firewood production, the NPVs were negative against all three discount rates in both study areas. I conclude by proposing a four-step integrated approach that can aid the successful incorporation of ES into decision-making: (1) maintain a balance between the social, economic and ecological aspects when making decisions on ES, (2) strive for an evidence- based approach to decision-making (use quantities and values), (3) apply integrated approaches (methods and techniques) to quantification and valuation, and (4) communicate all steps along the way. The results of this study will serve as a baseline for integration of ES into decision-making in SA.
- Full Text:
- Date Issued: 2017
- Authors: Ntshane, Basane Claire
- Date: 2017
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/4536 , vital:20686
- Description: Despite their contribution to human well-being, ecosystem services (ES) are being destroyed by anthropogenic activities, taken for granted and often compromised during land use decision making. The question that often arises is, what value do ES have compared to other undertakings that are economically robust, such as mining? The vision of the Millenium Ecosystem Assessment (MA) was a world in which natural assets (including ES) are appreciated and integrated into decision-making. The biodiversity strategy of the Convention on Biological Diversity (CBD) also concerns the integration of natural assets into decision making. Responding to challenges facing ES and their mainstreaming into decision-making has been constrained by lack of data and requires new tools and approaches. Integrating natural assets into decision-making is very important for South Africa (SA), where ES have been a crucial part of human systems for decades, and also because of the country’s commitment to the implementation of the CBD's biodiversity strategy. With the aim of incorporating ES into decision-making in an integrated way, this study was conducted in two biosphere reserves (BRs), Vhembe and Waterberg, in Limpopo Province, SA. The aims of the study were the identification, mapping and valuation of ES following an integrated approach. In order to achieve these aims, the study attempted to address four key objectives: (1) to assess and evaluate the status of mapping and valuation of ES in SA, (2) to identify and quantify ES and their indicators, (3) to investigate and analyse the impact of land use/cover (LU/LC) change to ES and (4) to conduct valuation of selected ES. Two separate literature reviews were undertaken to assess and evaluate the status of mapping and valuation of ES in SA, thus addressing study objective 1. Both reviews detected a significant research gap with regard to mapping and valuation of supporting services in SA. To identify ES and indicators provided by the two BRs and to assess the impact of LU/LC change and its effect on ES, a participatory scenario planning process was conducted under three different scenarios, namely ecological development, social development and economic development. It became clear that LU issues were diverse in nature and affected ES in a number of ways and that there were always trade-offs in the choice of LU. For example, yields of ES were best in the ecological development scenario and were affected negatively, together with agricultural commodity production, in the social development and economic development scenarios. A mapping exercise was undertaken to illustrate the spatial distribution of ES supply and demand, involving five ES and 15 indicators using existing datasets and the Integrated Valuation of Ecosystem Services and Trade-offs (InVEST) mapping tool, again addressing objective 2 of the study. Carbon storage and habitat quality were assessed, modelled and quantified and their values provided in biophysical terms using InVEST modelling tools, thus addressing objective 4 of the study. High quantities of carbon storage and high habitat quality were recorded in natural areas and low quantities were recorded in managed systems (cultivated, urban and plantation areas). InVEST was again applied to conduct an economic valuation of two provisioning ES, timber and firewood, by determining their net present values, attempting to address objective 4 of the study. Results revealed that, at 12% discount rate, the net present value (NPV) for timber production accounted for R23 317/ha in VBR and R57 304/ha in WBR. However, at lower discount rates (4 and 7%), the NPVs for timber were negative in VBR and positive in WBR. With regard to firewood production, the NPVs were negative against all three discount rates in both study areas. I conclude by proposing a four-step integrated approach that can aid the successful incorporation of ES into decision-making: (1) maintain a balance between the social, economic and ecological aspects when making decisions on ES, (2) strive for an evidence- based approach to decision-making (use quantities and values), (3) apply integrated approaches (methods and techniques) to quantification and valuation, and (4) communicate all steps along the way. The results of this study will serve as a baseline for integration of ES into decision-making in SA.
- Full Text:
- Date Issued: 2017
Ellipsis in the vP domain in Mandarin and Xhosa
- Authors: Ma, Xiujie
- Date: 2017
- Subjects: Grammar, Comparative and general -- Ellipsis , Chinese lanaguage -- Ellipsis , Chinese lanaguage -- Grammar, Comparative -- Xhosa , Xhosa lanaguage -- Ellipsis , Xhosa lanaguage -- Grammar, Comparative -- Chinese
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/43105 , vital:25266
- Description: This thesis provides a unified analysis of ellipsis in the vP domain in two typologically different languages, Mandarin and Xhosa from a generative perspective. It starts with the V-stranding Verb Phrase Ellipsis (VPE) assumption and shows that Mandarin and Xhosa do not have V-stranding VPE. The evidence for this is that in both languages, the constituents that remain in vP obligatorily are not allowed to be deleted, whereas the ones that can/must move out of vP can be deleted. The deleted constituents display the characteristics of PF-deletion, i.e. they have an internal syntactic structure. Based on the parallel between movement and ellipsis of the vP-internal constituents, I propose the Ellipsis EPP Hypothesis to account for ellipsis in the vP domain. The Hypothesis predicts that there is an Ellipsis Phrase at the left periphery of vP. The EP bears an Ellipsis-EPP (EEPP) feature, which must be satisfied. Maximal phrases in the c-command domain of EP are all potential candidates for satisfying the EEPP feature by moving to [Spec, EP]. However, only the phrases that are allowed to move out of vP can move to [Spec, EP] as EP is located above vP. Moreover, the movement to [Spec, EP] is subject to the syntactic and semantic restrictions in structure-building in that ellipsis is one operation in the course of structure-building and the derivation will continue after ellipsis takes place. The EEPP feature renders an XP in the specifier phonetically empty and syntactically frozen; therefore, a constituent will be deleted as soon as it moves to [Spec, EP]. The Hypothesis is schematically represented below. The Ellipsis EPP Hypothesis adequately accounts for the ellipsis of various vP-internal constituents - NPs, DPs, infinitive complements and CP complements - in both Mandarin and Xhosa. At the same time, it reveals the reasons why vP is precluded from being elided in these two languages. In Mandarin vP moves to [Spec, AspPi] to check the uninterpretable [asp] feature and in Xhosa vP moves to [Spec, FocP] to realize the focus; consequently, vP may not move to [Spec, EP] for ellipsis.
- Full Text:
- Date Issued: 2017
- Authors: Ma, Xiujie
- Date: 2017
- Subjects: Grammar, Comparative and general -- Ellipsis , Chinese lanaguage -- Ellipsis , Chinese lanaguage -- Grammar, Comparative -- Xhosa , Xhosa lanaguage -- Ellipsis , Xhosa lanaguage -- Grammar, Comparative -- Chinese
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/43105 , vital:25266
- Description: This thesis provides a unified analysis of ellipsis in the vP domain in two typologically different languages, Mandarin and Xhosa from a generative perspective. It starts with the V-stranding Verb Phrase Ellipsis (VPE) assumption and shows that Mandarin and Xhosa do not have V-stranding VPE. The evidence for this is that in both languages, the constituents that remain in vP obligatorily are not allowed to be deleted, whereas the ones that can/must move out of vP can be deleted. The deleted constituents display the characteristics of PF-deletion, i.e. they have an internal syntactic structure. Based on the parallel between movement and ellipsis of the vP-internal constituents, I propose the Ellipsis EPP Hypothesis to account for ellipsis in the vP domain. The Hypothesis predicts that there is an Ellipsis Phrase at the left periphery of vP. The EP bears an Ellipsis-EPP (EEPP) feature, which must be satisfied. Maximal phrases in the c-command domain of EP are all potential candidates for satisfying the EEPP feature by moving to [Spec, EP]. However, only the phrases that are allowed to move out of vP can move to [Spec, EP] as EP is located above vP. Moreover, the movement to [Spec, EP] is subject to the syntactic and semantic restrictions in structure-building in that ellipsis is one operation in the course of structure-building and the derivation will continue after ellipsis takes place. The EEPP feature renders an XP in the specifier phonetically empty and syntactically frozen; therefore, a constituent will be deleted as soon as it moves to [Spec, EP]. The Hypothesis is schematically represented below. The Ellipsis EPP Hypothesis adequately accounts for the ellipsis of various vP-internal constituents - NPs, DPs, infinitive complements and CP complements - in both Mandarin and Xhosa. At the same time, it reveals the reasons why vP is precluded from being elided in these two languages. In Mandarin vP moves to [Spec, AspPi] to check the uninterpretable [asp] feature and in Xhosa vP moves to [Spec, FocP] to realize the focus; consequently, vP may not move to [Spec, EP] for ellipsis.
- Full Text:
- Date Issued: 2017
Emancipatory politics and the Mpondo revolts
- Authors: Bruchhausen, Sarah
- Date: 2017
- Subjects: Pondo Revolt, South Africa, 1960-1963 , South Africa -- History -- 20th century , South Africa -- Politics and government -- 20th century
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/5093 , vital:20765
- Description: This thesis aims to offer a revised view of the Mpondo revolts. The central theoretical concept of the thesis is that of emancipatory politics. Drawing predominantly on archival sources the primary concern of the thesis is to expose and interrogate certain aspects of this historical moment of popular politics which can be seen as emancipatory. In particular the notions of egalitarianism and universal human dignity will be analysed in relation to the popular political subjectivities, formations and praxes of the Mpondo revolts. In so doing this thesis attempts to make a meaningful contribution to present day debates concerning alternative theories of human emancipation by showing what emancipatory politics looked like historically and in practise within the context of the Mpondo revolts.
- Full Text:
- Date Issued: 2017
- Authors: Bruchhausen, Sarah
- Date: 2017
- Subjects: Pondo Revolt, South Africa, 1960-1963 , South Africa -- History -- 20th century , South Africa -- Politics and government -- 20th century
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/5093 , vital:20765
- Description: This thesis aims to offer a revised view of the Mpondo revolts. The central theoretical concept of the thesis is that of emancipatory politics. Drawing predominantly on archival sources the primary concern of the thesis is to expose and interrogate certain aspects of this historical moment of popular politics which can be seen as emancipatory. In particular the notions of egalitarianism and universal human dignity will be analysed in relation to the popular political subjectivities, formations and praxes of the Mpondo revolts. In so doing this thesis attempts to make a meaningful contribution to present day debates concerning alternative theories of human emancipation by showing what emancipatory politics looked like historically and in practise within the context of the Mpondo revolts.
- Full Text:
- Date Issued: 2017
Emathunjini omhlaba kuhlala abantu
- Authors: Moya, Mlandeli Wellington
- Date: 2017
- Subjects: Short stories, Xhosa
- Language: Xhosa , English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/7235 , vital:21231
- Description: My short stories are about the circumstances in which black gold miners in Welkom in the 1980s and 1990s found themselves. These mineworkers - I was one of them - made up a large, uneducated segment of personnel because our work required strength and good health only. We came from all over the African continent. The places we had to live in were like jails or military barracks, sometimes with twenty or more of us sharing a single room. Because of these conditions, we shared our pains, and the pains of wives, children and relatives of those who were killed or disabled by their work, the repatriation of those who lost their capacity to continue working because of accidents and work, and work-related illnesses. We did not share the same language, and so we had to learn Fanakalo, the language of South African mine workers. My stories show how pain and happiness rub shoulders with each other in the miners' life, because besides the dangerous work there was also cultural entertainment, religious practices, robbery by tsotsis, and many prostitutes. The book Buzani Kubawo by Witness K. Tamsanqa has been an important influence on my writing. Other influences have been L.L. Sebe's Ucamngco and P.T. Mtuze's Alitshoni Lingaphumi. , La mabali angeemeko zabembi-migodi baseWelkom phaya kwiminyaka ephakathi koo-1980 noo-1990. Aba basebenzi, endandingomnye wabo, babeliqela elivisayo elingafundanga — bezingca ngamandla. Sasiphuma mbombo zonke zeli lase-Afrika. Indawo esasihlala kuyo ibifana nqwa nezisele zentolongo okanye izindlu zasemkhosini. Amashumi amabini amadoda elala ndlwini - nye. Ngenxa yaloo meko sachubelana amabali ngeemeko zobomi bethu, ngabafazi nabantwana, nezizalwane, nangeengozi esasingena kuzo nokugoduswa kwabo bagulayo. Kwathi kuba sasithetha iilwimi ngeelwimi safundiswa isiFanakalo. Amabali am abonisa iintlungu ezayame kulonwabo kuloo meko yasemigodini kuba yayikho nemidlalo nemigcobo ezonwabisayo ngokweentlanga ngeentlanga. Sasikwajongene nootsotsi kunye neentwazana ezithengisa ngemizimba. Ababhali abathe banefuthe ekubhaleni kwam baquka aba: uW.K. Thamsanqa ngencwadi yakhe ethi "Buzani kubawo," uP.T. Mtuze ngeyakhe ethi "Alitshoni Lingaphumi," kunye no L.L. Sebe ngencwadi yakhe ethi "Ucamngco."
- Full Text:
- Date Issued: 2017
- Authors: Moya, Mlandeli Wellington
- Date: 2017
- Subjects: Short stories, Xhosa
- Language: Xhosa , English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/7235 , vital:21231
- Description: My short stories are about the circumstances in which black gold miners in Welkom in the 1980s and 1990s found themselves. These mineworkers - I was one of them - made up a large, uneducated segment of personnel because our work required strength and good health only. We came from all over the African continent. The places we had to live in were like jails or military barracks, sometimes with twenty or more of us sharing a single room. Because of these conditions, we shared our pains, and the pains of wives, children and relatives of those who were killed or disabled by their work, the repatriation of those who lost their capacity to continue working because of accidents and work, and work-related illnesses. We did not share the same language, and so we had to learn Fanakalo, the language of South African mine workers. My stories show how pain and happiness rub shoulders with each other in the miners' life, because besides the dangerous work there was also cultural entertainment, religious practices, robbery by tsotsis, and many prostitutes. The book Buzani Kubawo by Witness K. Tamsanqa has been an important influence on my writing. Other influences have been L.L. Sebe's Ucamngco and P.T. Mtuze's Alitshoni Lingaphumi. , La mabali angeemeko zabembi-migodi baseWelkom phaya kwiminyaka ephakathi koo-1980 noo-1990. Aba basebenzi, endandingomnye wabo, babeliqela elivisayo elingafundanga — bezingca ngamandla. Sasiphuma mbombo zonke zeli lase-Afrika. Indawo esasihlala kuyo ibifana nqwa nezisele zentolongo okanye izindlu zasemkhosini. Amashumi amabini amadoda elala ndlwini - nye. Ngenxa yaloo meko sachubelana amabali ngeemeko zobomi bethu, ngabafazi nabantwana, nezizalwane, nangeengozi esasingena kuzo nokugoduswa kwabo bagulayo. Kwathi kuba sasithetha iilwimi ngeelwimi safundiswa isiFanakalo. Amabali am abonisa iintlungu ezayame kulonwabo kuloo meko yasemigodini kuba yayikho nemidlalo nemigcobo ezonwabisayo ngokweentlanga ngeentlanga. Sasikwajongene nootsotsi kunye neentwazana ezithengisa ngemizimba. Ababhali abathe banefuthe ekubhaleni kwam baquka aba: uW.K. Thamsanqa ngencwadi yakhe ethi "Buzani kubawo," uP.T. Mtuze ngeyakhe ethi "Alitshoni Lingaphumi," kunye no L.L. Sebe ngencwadi yakhe ethi "Ucamngco."
- Full Text:
- Date Issued: 2017
Estuary-dependency and multiple habitat connectivity of juvenile leervis lichia amia (pisces: carangidae) and the factors influencing their movements
- Authors: Murray, Taryn Sara
- Date: 2017
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/4477 , vital:20676
- Description: Estuaries are highly productive ecosystems that provide an important nursery function to many marine-spawning fish species. While in estuaries, the juveniles of estuary-associated fishes are exposed to frequent, abrupt changes in environmental conditions and, as such, utilise movement as a strategy to cope with the changing conditions. Therefore, to gain a better understanding of the importance of estuaries (i.e. estuary-dependency) to estuary-associated species, knowledge on their movement patterns within estuaries, the links between habitats, and the environmental and cyclical processes driving these movements, is necessary. Lichia amia, commonly known as leervis or garrick in southern Africa, is an over-exploited, estuary-dependent fishery species targeted by coastal recreational and subsistence fishers, as well as spearfishers, throughout its South African distribution. Aspects of its biology and life history have been assessed; however, knowledge on its movement behaviour is limited to a single conventional dart tagging study, which described large-scale coastal movements of juvenile, sub-adult and adult leervis. As such, little is known about area use and movement patterns within estuaries, or the degree of connectivity between estuarine and marine habitats. Therefore, the aim of this study, using conventional dart tagging and passive acoustic telemetry methods, was to assess the role of estuarine nursery habitats in the life cycle of the leervis by examining area use patterns and movement behaviour within estuaries, investigating the degree of habitat connectivity, and determining the drivers (cyclical rhythms and environmental variables) of estuarine use and connectivity. A dedicated conventional mark-recapture study on juvenile leervis within the Swartkops Estuary revealed a high level of estuarine fidelity (philopatry) suggesting that estuaries are important nursery habitats. However, movement distances increased with increasing fish length, with some fish also being recaptured in the neighbouring marine environment. These results provided evidence of an ontogenetic habitat shift, with smaller fish remaining in the estuary for extended periods and larger individuals undertaking more extensive movements. Complementary passive acoustic telemetry studies were conducted in the Kowie and Goukou estuaries, spaced 620 km apart, to assess area use, movement patterns, residency and multiple habitat connectivity of juvenile leervis. These telemetry studies showed varying levels of residency within the tagging estuaries, and seasonal variation in area use. The lengths of estuary used by leervis tagged in the Kowie Estuary generally decreased with the onset of austral winter, while fish tagged in the Goukou Estuary generally moved into the marine environment. Despite tagged individuals spending on average 56% and 38% of the total monitoring periods within the Kowie and Goukou estuaries, respectively, fish displayed high levels of multiple habitat connectivity, with 71% and 76% of Kowie and Goukou fish, respectively, visiting adjacent marine and estuarine environments. A total of 11 different neighbouring habitats (estuaries and ports) were visited by Kowie fish, while fish tagged in the Goukou Estuary only visited four adjacent habitats. These differences in connectivity could be attributed to the proximity of many more estuaries to the Kowie Estuary compared to the Goukou Estuary. Estuarine movements by acoustically tagged leervis in both estuaries followed a strong diel but a much weaker tidal pattern. A number of environmental variables significantly influenced estuarine movements and marine excursions (including river inflow, photoperiod and moon phase). However, water temperature (river and sea) had the most significant effects on these movements, with decreasing winter river temperatures coincident with a downstream shift in mean daily position of fish tagged in the Kowie Estuary, and movement into the marine environment from the Goukou Estuary. Interestingly, the area use patterns of juvenile leervis tagged in the Kowie and Goukou estuaries were different, predominantly using limited portions of each estuary. Kowie fish spent more time in the mouth region and lower reaches, while Goukou fish spent more time in the lower and middle reaches of the estuary. Therefore, should no-take Estuarine Protected Areas be implemented, inter-estuary differences would need to be considered to determine the most effective stretches of estuary to close to provide maximum protection for leervis. This study provided new information on the movement behaviour of juvenile leervis, the degree to which juveniles depend on estuaries as nursery areas, and the cyclical rhythms and environmental factors influencing their movements. The study therefore contributes considerably to our understanding of the role of estuaries in the life history of leervis, and provides essential information for the improved management of this over-exploited species.
- Full Text:
- Date Issued: 2017
- Authors: Murray, Taryn Sara
- Date: 2017
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/4477 , vital:20676
- Description: Estuaries are highly productive ecosystems that provide an important nursery function to many marine-spawning fish species. While in estuaries, the juveniles of estuary-associated fishes are exposed to frequent, abrupt changes in environmental conditions and, as such, utilise movement as a strategy to cope with the changing conditions. Therefore, to gain a better understanding of the importance of estuaries (i.e. estuary-dependency) to estuary-associated species, knowledge on their movement patterns within estuaries, the links between habitats, and the environmental and cyclical processes driving these movements, is necessary. Lichia amia, commonly known as leervis or garrick in southern Africa, is an over-exploited, estuary-dependent fishery species targeted by coastal recreational and subsistence fishers, as well as spearfishers, throughout its South African distribution. Aspects of its biology and life history have been assessed; however, knowledge on its movement behaviour is limited to a single conventional dart tagging study, which described large-scale coastal movements of juvenile, sub-adult and adult leervis. As such, little is known about area use and movement patterns within estuaries, or the degree of connectivity between estuarine and marine habitats. Therefore, the aim of this study, using conventional dart tagging and passive acoustic telemetry methods, was to assess the role of estuarine nursery habitats in the life cycle of the leervis by examining area use patterns and movement behaviour within estuaries, investigating the degree of habitat connectivity, and determining the drivers (cyclical rhythms and environmental variables) of estuarine use and connectivity. A dedicated conventional mark-recapture study on juvenile leervis within the Swartkops Estuary revealed a high level of estuarine fidelity (philopatry) suggesting that estuaries are important nursery habitats. However, movement distances increased with increasing fish length, with some fish also being recaptured in the neighbouring marine environment. These results provided evidence of an ontogenetic habitat shift, with smaller fish remaining in the estuary for extended periods and larger individuals undertaking more extensive movements. Complementary passive acoustic telemetry studies were conducted in the Kowie and Goukou estuaries, spaced 620 km apart, to assess area use, movement patterns, residency and multiple habitat connectivity of juvenile leervis. These telemetry studies showed varying levels of residency within the tagging estuaries, and seasonal variation in area use. The lengths of estuary used by leervis tagged in the Kowie Estuary generally decreased with the onset of austral winter, while fish tagged in the Goukou Estuary generally moved into the marine environment. Despite tagged individuals spending on average 56% and 38% of the total monitoring periods within the Kowie and Goukou estuaries, respectively, fish displayed high levels of multiple habitat connectivity, with 71% and 76% of Kowie and Goukou fish, respectively, visiting adjacent marine and estuarine environments. A total of 11 different neighbouring habitats (estuaries and ports) were visited by Kowie fish, while fish tagged in the Goukou Estuary only visited four adjacent habitats. These differences in connectivity could be attributed to the proximity of many more estuaries to the Kowie Estuary compared to the Goukou Estuary. Estuarine movements by acoustically tagged leervis in both estuaries followed a strong diel but a much weaker tidal pattern. A number of environmental variables significantly influenced estuarine movements and marine excursions (including river inflow, photoperiod and moon phase). However, water temperature (river and sea) had the most significant effects on these movements, with decreasing winter river temperatures coincident with a downstream shift in mean daily position of fish tagged in the Kowie Estuary, and movement into the marine environment from the Goukou Estuary. Interestingly, the area use patterns of juvenile leervis tagged in the Kowie and Goukou estuaries were different, predominantly using limited portions of each estuary. Kowie fish spent more time in the mouth region and lower reaches, while Goukou fish spent more time in the lower and middle reaches of the estuary. Therefore, should no-take Estuarine Protected Areas be implemented, inter-estuary differences would need to be considered to determine the most effective stretches of estuary to close to provide maximum protection for leervis. This study provided new information on the movement behaviour of juvenile leervis, the degree to which juveniles depend on estuaries as nursery areas, and the cyclical rhythms and environmental factors influencing their movements. The study therefore contributes considerably to our understanding of the role of estuaries in the life history of leervis, and provides essential information for the improved management of this over-exploited species.
- Full Text:
- Date Issued: 2017
Evaluating the impact of responsible investing strategies on fund performance
- Authors: Ntuli, Thulani
- Date: 2017
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: http://hdl.handle.net/10962/7067 , vital:21214
- Description: Several studies have been undertaken to evaluate performance of responsible investments, that is, funds that integrate ethical as well as environmental, social and governance considerations in the investment process (ESG). Particularly to address the question whether it is possible for investors to do well while doing good. Modern Portfolio Theory predicts sub-optimal performance for funds constructed on any basis other than risk-reward optimisation. These studies usually compare performance of responsible investments with conventional funds or an unrestricted benchmark portfolio. The findings have been contradictory and on the main inconclusive. Underlying this contradiction is the treatment of responsible investments funds as a homogenous group of funds and not acknowledging their heterogeneity owing to methods and strategies used to construct them. This study seeks to address this gap in the literature by investigating the impact of responsible investment strategies on fund performance. The performance of nine South African responsible investment funds constructed and manged using different responsible investing strategies are analysed over a five-year period from 01 October 2010 to 31 October 2015. Their performance is benchmarked against the JSE ALL Share Index (ALSI) and the FTES/JSE SRI index. Specifically, the average monthly returns, variability and Sharpe ratio of the constituent fund is used to compare performance. Moreover, the CAPM based Jensen alpha is used to determine any significant under or overperformance of respective funds relative to the benchmarks. The study found to be no difference in average monthly returns and risk relative to the two benchmark indices for all respective strategies. However, funds constructed using the negative screening strategy generally underperform. These funds overall deliver a statistically significant lower alpha. It is concluded that this RI investing strategy is not suitable for investors concerned about a trade-off between fund performance and ESG performance.
- Full Text:
- Date Issued: 2017
- Authors: Ntuli, Thulani
- Date: 2017
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: http://hdl.handle.net/10962/7067 , vital:21214
- Description: Several studies have been undertaken to evaluate performance of responsible investments, that is, funds that integrate ethical as well as environmental, social and governance considerations in the investment process (ESG). Particularly to address the question whether it is possible for investors to do well while doing good. Modern Portfolio Theory predicts sub-optimal performance for funds constructed on any basis other than risk-reward optimisation. These studies usually compare performance of responsible investments with conventional funds or an unrestricted benchmark portfolio. The findings have been contradictory and on the main inconclusive. Underlying this contradiction is the treatment of responsible investments funds as a homogenous group of funds and not acknowledging their heterogeneity owing to methods and strategies used to construct them. This study seeks to address this gap in the literature by investigating the impact of responsible investment strategies on fund performance. The performance of nine South African responsible investment funds constructed and manged using different responsible investing strategies are analysed over a five-year period from 01 October 2010 to 31 October 2015. Their performance is benchmarked against the JSE ALL Share Index (ALSI) and the FTES/JSE SRI index. Specifically, the average monthly returns, variability and Sharpe ratio of the constituent fund is used to compare performance. Moreover, the CAPM based Jensen alpha is used to determine any significant under or overperformance of respective funds relative to the benchmarks. The study found to be no difference in average monthly returns and risk relative to the two benchmark indices for all respective strategies. However, funds constructed using the negative screening strategy generally underperform. These funds overall deliver a statistically significant lower alpha. It is concluded that this RI investing strategy is not suitable for investors concerned about a trade-off between fund performance and ESG performance.
- Full Text:
- Date Issued: 2017
Evaluating the share performance of socially responsible investment on the Johannesburg Stock Exchange
- Authors: Cormack, Bradley Alexander
- Date: 2017
- Subjects: Investments -- Moral and ethical aspects -- South Africa , Johannesburg Stock Exchange , Social responsibility of business -- Standards , Social responsiblity of business -- South Africa
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: http://hdl.handle.net/10962/36251 , vital:24532
- Description: Socially responsible investing (SRI) integrates environmental, social and governance (ESG) issues into the investment decision-making process. Growing ESG concerns and the uncovering of corporate scandals have catalysed the substantial growth in SRI portfolios worldwide. Notwithstanding its increasing popularity, barriers to further SRI growth have been identified. Traditional investing practices suggest that theoretically, SRI may underperform conventional investment strategies. However, despite the vast amount of literature on SRI, empirical studies have yielded a mixture of results regarding fund performance. The JSE SRI Index was launched in 2004 to promote transparent business practices. It was discontinued at the end of 2015 succeeded by a new Responsible Investment Index established by the JSE in association with FTSE Russell. The aim of the research was to evaluate the share performance of the JSE SRI Index from 2004-2015. Additionally, the indices were categorised by environmental impact to further analyse disparity among share returns. The study was also divided into two sub-periods, 2004-2009 and 2010-2015, with the latter following the endorsement of integrated reporting by the King III Code as a listing requirement in 2010. A single-factor Capital Asset Pricing Model (CAPM) was used to assess differences in risk-adjusted returns. Engle-Granger and Johansen tests were employed to explore the possibility of a cointegrating relationship between the indices. No significant difference between returns was observed for 2004-2009, with the SRI Index exhibiting statistically significant inferior risk-adjusted returns for the latter half of the study. Overall, a significant difference between share returns was found, with CAPM results suggesting that the JSE SRI Index underperformed the All Share Index by -2.33% per annum throughout the time span of the study. Engle-Granger and Johansen test results indicated the existence of a cointegrating relationship over the first half of the study. However, there was no cointegration between the two indices for 2004-2015, which may be attributed to no significant relationship found for the latter years. Results support the notion that investors pay the price to invest ethically on the JSE. Inferior risk-adjusted returns associated with SRI may be a major barrier to its development in South African markets.
- Full Text:
- Date Issued: 2017
- Authors: Cormack, Bradley Alexander
- Date: 2017
- Subjects: Investments -- Moral and ethical aspects -- South Africa , Johannesburg Stock Exchange , Social responsibility of business -- Standards , Social responsiblity of business -- South Africa
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: http://hdl.handle.net/10962/36251 , vital:24532
- Description: Socially responsible investing (SRI) integrates environmental, social and governance (ESG) issues into the investment decision-making process. Growing ESG concerns and the uncovering of corporate scandals have catalysed the substantial growth in SRI portfolios worldwide. Notwithstanding its increasing popularity, barriers to further SRI growth have been identified. Traditional investing practices suggest that theoretically, SRI may underperform conventional investment strategies. However, despite the vast amount of literature on SRI, empirical studies have yielded a mixture of results regarding fund performance. The JSE SRI Index was launched in 2004 to promote transparent business practices. It was discontinued at the end of 2015 succeeded by a new Responsible Investment Index established by the JSE in association with FTSE Russell. The aim of the research was to evaluate the share performance of the JSE SRI Index from 2004-2015. Additionally, the indices were categorised by environmental impact to further analyse disparity among share returns. The study was also divided into two sub-periods, 2004-2009 and 2010-2015, with the latter following the endorsement of integrated reporting by the King III Code as a listing requirement in 2010. A single-factor Capital Asset Pricing Model (CAPM) was used to assess differences in risk-adjusted returns. Engle-Granger and Johansen tests were employed to explore the possibility of a cointegrating relationship between the indices. No significant difference between returns was observed for 2004-2009, with the SRI Index exhibiting statistically significant inferior risk-adjusted returns for the latter half of the study. Overall, a significant difference between share returns was found, with CAPM results suggesting that the JSE SRI Index underperformed the All Share Index by -2.33% per annum throughout the time span of the study. Engle-Granger and Johansen test results indicated the existence of a cointegrating relationship over the first half of the study. However, there was no cointegration between the two indices for 2004-2015, which may be attributed to no significant relationship found for the latter years. Results support the notion that investors pay the price to invest ethically on the JSE. Inferior risk-adjusted returns associated with SRI may be a major barrier to its development in South African markets.
- Full Text:
- Date Issued: 2017
Evaluation of low-cost technology options for sustainable water supply and sanitation in two peri-urban areas of Lusaka, Zambia: opportunities and constraints
- Authors: Chiliboyi, Yvonne
- Date: 2017
- Subjects: Toilets -- Technological innovations -- South Africa , Sanitary engineering -- Technological innovations -- South Africa , Water resoures development -- Technological innovations -- South Africa , Water-supply -- Technological innovations -- South Africa , Household surveys -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/7960 , vital:21328
- Description: Presently, at least 70% of the total urban population in Zambia resides in peri-urban areas. Peri-urban settlements are characterized by high population growth, high poverty levels and inadequate access to water and sanitation which often result in increased prevalence of diseases. The situation is even made worse because of the position that many local authorities have taken regarding the implementation of infrastructure and service development in these settlements. Local authorities in developing countries have continuously focused on implementation of traditional and unsustainable technologies for service provision to meet the demand despite the technologies’ inability to serve the rapidly growing peri-urban areas. These technologies have high costs, lack proper operation and maintenance, and are not affordable to majority of peri-urban residents. Therefore, this study was set out to identify and evaluate the existing and possible low-cost technology options for sustainable water supply and sanitation in two selected peri-urban areas of Lusaka, Zambia, namely Kanyama and Chazanga. This was achieved through a household survey conducted in the selected communities. Questionnaires and focus group discussions were held in the respective areas to obtain baseline data on the current water supply and sanitation situation, the type of technologies used, challenges faced regarding water and sanitation technologies, and to get the communities perceptions and preferences of different technology options. Thereafter, a Multi-Criterion Analysis methodological approach was used to assess the selected technologies by the communities, taking into consideration of the economic, socio-cultural, technical, institutional and environmental aspects. Results from the study revealed that a few low-cost water supply and sanitation technologies are feasible for peri-urban areas. For Chazanga, communal taps, boreholes, protected wells, and rain water harvesting were found to be feasible for water supply. For sanitation, on-site sanitation services such as compost toilets, dry toilets, as well as Ventilated Improved Pits (VIP) and Pour-flush, Fossa Alterna and the Urine Diversion Dry Toilet (UDDT) are some of the low-cost technologies that can be implemented in the area. The VIP is suitable for households that rely on water from communal taps for their use. As majority of households in the area have taps on their plots, the Pour-flush can be an alternative. The Fossa Alterna and the Urine Diversion Dry Toilet (UDDT) have low initial cost and can accommodate different households. Additionally, the area has a lower household size and majority of the residents in the area landlords, which makes it easy to teach users how the toilet operates as well as its maintenance. For Kanyama, feasible and sustainable low-cost water supply facilities include boreholes and communal taps. Kanyama has limited plot sizes thereby causing the challenge of implementing infrastructure such as rainwater harvesting. Additionally, continuous increase in urban population in the area, coupled with the construction of unregulated households and sanitation facilities, renders protected wells not feasible to implement in Kanyama. In terms of sanitation, wet on-site sanitation facilities such as Ventilated Improved Pit (VIP) latrines are accepted by the community. The VIP does not require water for use and if properly constructed can be used as a bathroom. The Pour-flush toilet is also another alternative for provision of sanitation in the area. However, the latrine can be expensive to construct for majority of the residents. Dry sanitation such as the Urine Diversion Dry Toilet (UDDT) is not feasible for Kanyama. The UDDT requires continuous awareness on its use especially in rented households where tenants are constantly changing. The method of evaluating appropriate technology options for peri-urban areas and thereafter letting the users from the communities choose from the proposed technologies ensures a participatory approach. Results from Multi-Criterion Analysis (MCA) showed that stakeholders’ influence is essential for the selection of sustainable technology options. However, it is important that the implementation process of any technology in peri-urban areas consider different aspects including the local environmental, socio-cultural, economic, technical, and institutional conditions. Finally, the outcome of this study will not only provide baseline data for successful implementation of appropriate low-cost water supply and sanitation technology options in Chazanga and Kanyama, but also other peri-urban communities in Zambia.
- Full Text:
- Date Issued: 2017
- Authors: Chiliboyi, Yvonne
- Date: 2017
- Subjects: Toilets -- Technological innovations -- South Africa , Sanitary engineering -- Technological innovations -- South Africa , Water resoures development -- Technological innovations -- South Africa , Water-supply -- Technological innovations -- South Africa , Household surveys -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/7960 , vital:21328
- Description: Presently, at least 70% of the total urban population in Zambia resides in peri-urban areas. Peri-urban settlements are characterized by high population growth, high poverty levels and inadequate access to water and sanitation which often result in increased prevalence of diseases. The situation is even made worse because of the position that many local authorities have taken regarding the implementation of infrastructure and service development in these settlements. Local authorities in developing countries have continuously focused on implementation of traditional and unsustainable technologies for service provision to meet the demand despite the technologies’ inability to serve the rapidly growing peri-urban areas. These technologies have high costs, lack proper operation and maintenance, and are not affordable to majority of peri-urban residents. Therefore, this study was set out to identify and evaluate the existing and possible low-cost technology options for sustainable water supply and sanitation in two selected peri-urban areas of Lusaka, Zambia, namely Kanyama and Chazanga. This was achieved through a household survey conducted in the selected communities. Questionnaires and focus group discussions were held in the respective areas to obtain baseline data on the current water supply and sanitation situation, the type of technologies used, challenges faced regarding water and sanitation technologies, and to get the communities perceptions and preferences of different technology options. Thereafter, a Multi-Criterion Analysis methodological approach was used to assess the selected technologies by the communities, taking into consideration of the economic, socio-cultural, technical, institutional and environmental aspects. Results from the study revealed that a few low-cost water supply and sanitation technologies are feasible for peri-urban areas. For Chazanga, communal taps, boreholes, protected wells, and rain water harvesting were found to be feasible for water supply. For sanitation, on-site sanitation services such as compost toilets, dry toilets, as well as Ventilated Improved Pits (VIP) and Pour-flush, Fossa Alterna and the Urine Diversion Dry Toilet (UDDT) are some of the low-cost technologies that can be implemented in the area. The VIP is suitable for households that rely on water from communal taps for their use. As majority of households in the area have taps on their plots, the Pour-flush can be an alternative. The Fossa Alterna and the Urine Diversion Dry Toilet (UDDT) have low initial cost and can accommodate different households. Additionally, the area has a lower household size and majority of the residents in the area landlords, which makes it easy to teach users how the toilet operates as well as its maintenance. For Kanyama, feasible and sustainable low-cost water supply facilities include boreholes and communal taps. Kanyama has limited plot sizes thereby causing the challenge of implementing infrastructure such as rainwater harvesting. Additionally, continuous increase in urban population in the area, coupled with the construction of unregulated households and sanitation facilities, renders protected wells not feasible to implement in Kanyama. In terms of sanitation, wet on-site sanitation facilities such as Ventilated Improved Pit (VIP) latrines are accepted by the community. The VIP does not require water for use and if properly constructed can be used as a bathroom. The Pour-flush toilet is also another alternative for provision of sanitation in the area. However, the latrine can be expensive to construct for majority of the residents. Dry sanitation such as the Urine Diversion Dry Toilet (UDDT) is not feasible for Kanyama. The UDDT requires continuous awareness on its use especially in rented households where tenants are constantly changing. The method of evaluating appropriate technology options for peri-urban areas and thereafter letting the users from the communities choose from the proposed technologies ensures a participatory approach. Results from Multi-Criterion Analysis (MCA) showed that stakeholders’ influence is essential for the selection of sustainable technology options. However, it is important that the implementation process of any technology in peri-urban areas consider different aspects including the local environmental, socio-cultural, economic, technical, and institutional conditions. Finally, the outcome of this study will not only provide baseline data for successful implementation of appropriate low-cost water supply and sanitation technology options in Chazanga and Kanyama, but also other peri-urban communities in Zambia.
- Full Text:
- Date Issued: 2017
Evaluation of the acceptability of ambulatory blood pressure monitoring in a semi-rural, Eastern Cape population
- Authors: Chiwanza, Farisai
- Date: 2017
- Language: English
- Type: text , Thesis , Masters , MPharm
- Identifier: http://hdl.handle.net/10962/59161 , vital:27447
- Description: Expected release date-April 2019
- Full Text:
- Date Issued: 2017
- Authors: Chiwanza, Farisai
- Date: 2017
- Language: English
- Type: text , Thesis , Masters , MPharm
- Identifier: http://hdl.handle.net/10962/59161 , vital:27447
- Description: Expected release date-April 2019
- Full Text:
- Date Issued: 2017
Evictions, migrations and epidemiology in Gokwe during the colonial era
- Authors: Mudzimu, Asa
- Date: 2017
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/6946 , vital:21203
- Description: Gokwe, being infested with tsetse and mosquito was seen as a ‘diseased’ environment by the Europeans. Thus, colonial anti-disease campaigns were introduced during the first decade of the 20th century. Initially, the campaigns sought to address economic challenges in the colony as they involved African relocations for the benefit of the Europeans. However, this study argues that these anti-disease campaigns were modified with time and space. The key thrust of the paper is to examine the imbrication between evictions, migrations and disease control in the context of colonial public health system. Apartfrom examining the development of Western medical practices in Gokwe the dissertation explores how this colonial public health system coalesced or clashed with African worldviews. Gokwe matters as a ‘frontier’ society in many senses. Given colonial efforts to occupy Gokwe and the influx of new evictees and migrants in the 1960s, the study depicts Gokwe as a frontier. The study sees evictions and displacements as programmes tailored to arrest tsetse and the associated diseases in the Zambezi Valley.
- Full Text:
- Date Issued: 2017
- Authors: Mudzimu, Asa
- Date: 2017
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/6946 , vital:21203
- Description: Gokwe, being infested with tsetse and mosquito was seen as a ‘diseased’ environment by the Europeans. Thus, colonial anti-disease campaigns were introduced during the first decade of the 20th century. Initially, the campaigns sought to address economic challenges in the colony as they involved African relocations for the benefit of the Europeans. However, this study argues that these anti-disease campaigns were modified with time and space. The key thrust of the paper is to examine the imbrication between evictions, migrations and disease control in the context of colonial public health system. Apartfrom examining the development of Western medical practices in Gokwe the dissertation explores how this colonial public health system coalesced or clashed with African worldviews. Gokwe matters as a ‘frontier’ society in many senses. Given colonial efforts to occupy Gokwe and the influx of new evictees and migrants in the 1960s, the study depicts Gokwe as a frontier. The study sees evictions and displacements as programmes tailored to arrest tsetse and the associated diseases in the Zambezi Valley.
- Full Text:
- Date Issued: 2017
Evidence for a biological control-induced regime shift between floating and submerged invasive plant dominance in South Africa
- Authors: Strange, Emily Frances
- Date: 2017
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/32448 , vital:24044
- Description: South Africa has a long history battling the establishment and spread of invasive floating macrophytes. The negative consequences of these are costly both economically and ecologically. They form dense mats on the water's surface that deplete resources such as light and oxygen to the submerged community, which creates anoxic conditions, reduces biodiversity and limits access to freshwater. The past thirty years of South African invasive plant research and the implementation of nationwide biological control programmes has led to widespread control of these species in many degraded systems. Such initiatives are aimed at restoring access to potable freshwater and increasing native biodiversity. However, in recent years, where there has been a decline in floating invasive plant populations, an increase in the establishment and spread of submerged invasive plant species has been observed. Species such as Brazilian waterweed (Egeria densa (Planch.) (Hydrocharitaceae)) and Eurasian watermilfoil (Myriophyllum spicatum (L.) (Haloragaceae)) have been recorded in South African freshwater systems, posing significant threats to aquatic ecosystems. This thesis proposes that the biological control of floating invasive plants, which occurs in numerous dams and rivers nationwide, is the catalyst of a regime shift from floating invasive to submerged invasive plant dominance. Regime shifts are large and often sudden changes in the key structure and functioning of ecosystems, and studies into their occurrence and driving mechanisms broadens understanding of community structures and can guide effective resource management. In order to explore the existence of this new regime shift, a multi-platform approach using controlled experiments and ecological modelling techniques was employed. A model system was created consisting of a floating invasive (Pistia stratiotes L. (Araceae)), a submerged invasive (E. densa) and an ecologically analogous submerged native plant species (Lagarosiphon major (Ridl.) Moss (Hydrocharitaceae)). A suite of experiments was conducted to explore the interactions between the floating and submerged plants under varying regimes of floating plant biological control and levels of nutrient loading. These experiments revealed a competitive advantage of the invasive E. densa over the native L. major that increased by 86% under heavy nutrient loading. The relative growth rate and accumulated biomass of E. densa was significantly higher for plants grown in the presence of biologically controlled P. stratiotes (compared to insect free plants). This demonstrates a high capacity for the invasive E. densa to capitalise on resources made newly available through the biological control of the floating plants. In contrast, the native L. major fared poorly when grown in the presence of the floating P. stratiotes, regardless of applied biological control measures. The experimental observations were then used to parameterise a mathematical model, built to provide a holistic understanding of the individually assessed interactions which work together as the driving mechanisms underpinning the newly identified regime shift. This thesis utilised a multi-platform approach to build the first body of evidence in support of a newly recognised regime shift between floating invasive and submerged invasive plant dominance, as driven by biological control. The results indicate that a reduction in the nutrient loading of South Africa's freshwater systems will reduce negative impacts of submerged invasive macrophytes, whilst increasing system resilience against future invasion. The evidence presented has the potential to better inform management of South Africa's freshwater systems and highlights the importance of integrating multi-trophic interactions when considering future invasive plant management. This research also opens up a multitude of possibilities for studies into submerged plant invasion mechanisms and resilience of native macrophyte communities in South Africa, and further afield.
- Full Text:
- Date Issued: 2017
- Authors: Strange, Emily Frances
- Date: 2017
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/32448 , vital:24044
- Description: South Africa has a long history battling the establishment and spread of invasive floating macrophytes. The negative consequences of these are costly both economically and ecologically. They form dense mats on the water's surface that deplete resources such as light and oxygen to the submerged community, which creates anoxic conditions, reduces biodiversity and limits access to freshwater. The past thirty years of South African invasive plant research and the implementation of nationwide biological control programmes has led to widespread control of these species in many degraded systems. Such initiatives are aimed at restoring access to potable freshwater and increasing native biodiversity. However, in recent years, where there has been a decline in floating invasive plant populations, an increase in the establishment and spread of submerged invasive plant species has been observed. Species such as Brazilian waterweed (Egeria densa (Planch.) (Hydrocharitaceae)) and Eurasian watermilfoil (Myriophyllum spicatum (L.) (Haloragaceae)) have been recorded in South African freshwater systems, posing significant threats to aquatic ecosystems. This thesis proposes that the biological control of floating invasive plants, which occurs in numerous dams and rivers nationwide, is the catalyst of a regime shift from floating invasive to submerged invasive plant dominance. Regime shifts are large and often sudden changes in the key structure and functioning of ecosystems, and studies into their occurrence and driving mechanisms broadens understanding of community structures and can guide effective resource management. In order to explore the existence of this new regime shift, a multi-platform approach using controlled experiments and ecological modelling techniques was employed. A model system was created consisting of a floating invasive (Pistia stratiotes L. (Araceae)), a submerged invasive (E. densa) and an ecologically analogous submerged native plant species (Lagarosiphon major (Ridl.) Moss (Hydrocharitaceae)). A suite of experiments was conducted to explore the interactions between the floating and submerged plants under varying regimes of floating plant biological control and levels of nutrient loading. These experiments revealed a competitive advantage of the invasive E. densa over the native L. major that increased by 86% under heavy nutrient loading. The relative growth rate and accumulated biomass of E. densa was significantly higher for plants grown in the presence of biologically controlled P. stratiotes (compared to insect free plants). This demonstrates a high capacity for the invasive E. densa to capitalise on resources made newly available through the biological control of the floating plants. In contrast, the native L. major fared poorly when grown in the presence of the floating P. stratiotes, regardless of applied biological control measures. The experimental observations were then used to parameterise a mathematical model, built to provide a holistic understanding of the individually assessed interactions which work together as the driving mechanisms underpinning the newly identified regime shift. This thesis utilised a multi-platform approach to build the first body of evidence in support of a newly recognised regime shift between floating invasive and submerged invasive plant dominance, as driven by biological control. The results indicate that a reduction in the nutrient loading of South Africa's freshwater systems will reduce negative impacts of submerged invasive macrophytes, whilst increasing system resilience against future invasion. The evidence presented has the potential to better inform management of South Africa's freshwater systems and highlights the importance of integrating multi-trophic interactions when considering future invasive plant management. This research also opens up a multitude of possibilities for studies into submerged plant invasion mechanisms and resilience of native macrophyte communities in South Africa, and further afield.
- Full Text:
- Date Issued: 2017
Evolution of Fe-Ti-V oxides from the main magnetite layer, Upper Zone, Bushveld Complex, South Africa: a comparison across the Western, Northern and Eastern Lobes
- Authors: Iorga-Pavel, Adina
- Date: 2017
- Subjects: Magnetite -- South Africa -- Bushveld Complex , Mineralogy -- South Africa -- Bushveld Complex , Oxides
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/7357 , vital:21248
- Description: The Main Magnetite Layer (MML) from the Northern, Eastern and Western lobes of the Bushveld Complex shows significant differences in textures and in mineral chemistry. The MML in the Eastern and Western lobes is massive, with rare, small and altered pyroxene inclusions. By contrast, the MML in the Northern Lobe is more heterogeneous, and it is made of anastomosed and sometimes imbricated, thin layers of magnetitite, magnetite-rich and silicate-rich rocks, where the inclusions in Ti-magnetite are more numerous and consist of mainly altered subhedral and anhedral plagioclase. The comparison of the maximum values of the oxides shows that the MML in the Northern Lobe has the highest content of V2O3 (1.97 wt%), TiO2 (22.49 wt%) and MgO (2.92 wt%), while the MML in the Eastern Lobe has the highest content of Cr2O3 (2.92 wt%) and Al2O3 (9.80 wt%), but lowest V2O3 (0.52 wt%). The lower TiO2 content and higher V2O3 content in the MML of the Northern and Western Lobes suggest lower oxidising conditions during the crystallization of oxides. The MML in all three studied lobes consists of two layers of magnetitite, suggesting that MML was formed by two separate magma influxes, probably on a diverse and complex type of magma chamber floor. The high TiO2 content in magnetite, together with the negative correlation between TiO2 and V2O3 suggest that the maximum V content should represent a “less evolved” and less oxidized melt. In this respect, higher concentrations V2O3 in magnetite can be expected in magnetitite layers with lower TiO2. It can be inferred that the Ti-magetite in the MML from the Eastern Lobe was formed from a more evolved (TiO2 and FeO enriched) and more oxidized (lower V2O3) melt, compared with the MML from the Northern and Western lobes. These findings can be used to illustrate: a) that high fO2 can be responsible for the relatively low V content in magnetite from Fe-Ti oxide ores and b) the vanadium in magnetite decreases significantly in more evolved cumulates, due to a decreasing fO2 with differentiation. Compositional profiles of Ti- magnetite along the stratigraphic height of the MML in the Eastern Lobe (composed of two layers, separated in the outcrop by a parting plane) depicts a cryptic variation with depth in each of the two layers, where each layer can be divided into four sublayers, labelled upwards as A, B, C (with C1, C2, C3 and C4) and D based on Cr, Mg, Ti, Al and V variation. Small scale reversals of the mentioned elements and the repetition of A, B, C and D sub-layers in each layer suggest that MML formed from two successive influxes of magma (indicated by relatively elevated values of MgO), which evolved by crystallization and cooling in a similar manner, to produce the A to D variation. Based on these observations and theoretical considerations, this study dismisses several models for the genesis of the MML: the immiscibility, the increased oxygen fugacity, the relative increase of H2O content of the melt, pressure variation within the magma chamber, magma mixing, and crustal rock contamination. The model proposed here for MML genesis involves the crystallization of both Ti-magnetite and ilmenite from a Fe-Ti-Ca-Al-rich melt (ferro-diorite) along its line of descent, and gravitational settling of oxides in a dynamic regime. The factor which triggered the crystallization of magnetite is a critical saturation of melt in magnetite (attaining saturation of magnetite and ilmenite in the melt after some silicates crystallized). The difference between the nature of silicate inclusions in magnetite and the nature of the magnetite floor, suggest that the Fe-rich magma was not in equilibrium with the cumulates from the present floor, but rather it was emplaced laterally on long distances, the melt being disrupted from its own cumulates. The absence of correlation between the Cr2O3 in magnetite and co-existing ilmenite can indicate than no in-situ fractional crystallization took place at the moment of magnetite accumulation, but rather that magnetite and ilmenite gravitationally accumulated and the grains mechanically mixed from a flowing magma. The model presented herein proposes a five stage model of MML formation: Stage 1 is represented by the intrusion of a Fe-T-Ca-Al-rich magma which expands laterally within a flat and thin magma chamber. Oxides start to crystallize within a dynamic regime of the magma. Stage 2 is given by the accumulation of oxides at the bottom of the new floor. Some plagioclase starts to crystallize (e.g. subhedral plagioclase in the MML of the Northern Lobe). Stage 3 is a short living static regime, where both plagioclase and magnetite crystallized, without fractionation, forming the thin magnetite-anorthosite layer separating the MML into two layers. Stage 4 is represented by a new influx of Fe-Ti-Ca-Al-rich magma which is emplaced above the magnetite-bearing anorthosite, flushing out the liquid which was in equilibrium with the anorthosite. The oxides started crystallizing in a dynamic regime, as in Stage 1. In stage 5, the accumulation of oxides produced the upper layer of the MML. Our interpretation is that the flow of the magma was more dynamic (probably more turbulent on long distances) in the MML of the Northern Lobe, compared to the MML in the Western and Eastern lobes, producing highly heterogeneous and imbricated thin layers of magnetitite and silicates. The presence of olivine corona around orthopyroxene suggests the incongruent melting of orthopyroxene, which points out towards a local re-heating of existing silicate layers, this being a strong argument for multiple injections in generation of MML. Massive crystallization of oxides produced the sulphur saturation of the magma and caused the precipitation of the igneous sulphides, which nucleated on the existing oxides. Later hydrothermal fluids (and/or late magmatic volatiles?) percolated the MML, producing chloritization of the included silicates, remobilization of igneous sulphides and precipitation of hydrothermal sulphides.
- Full Text:
- Date Issued: 2017
- Authors: Iorga-Pavel, Adina
- Date: 2017
- Subjects: Magnetite -- South Africa -- Bushveld Complex , Mineralogy -- South Africa -- Bushveld Complex , Oxides
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/7357 , vital:21248
- Description: The Main Magnetite Layer (MML) from the Northern, Eastern and Western lobes of the Bushveld Complex shows significant differences in textures and in mineral chemistry. The MML in the Eastern and Western lobes is massive, with rare, small and altered pyroxene inclusions. By contrast, the MML in the Northern Lobe is more heterogeneous, and it is made of anastomosed and sometimes imbricated, thin layers of magnetitite, magnetite-rich and silicate-rich rocks, where the inclusions in Ti-magnetite are more numerous and consist of mainly altered subhedral and anhedral plagioclase. The comparison of the maximum values of the oxides shows that the MML in the Northern Lobe has the highest content of V2O3 (1.97 wt%), TiO2 (22.49 wt%) and MgO (2.92 wt%), while the MML in the Eastern Lobe has the highest content of Cr2O3 (2.92 wt%) and Al2O3 (9.80 wt%), but lowest V2O3 (0.52 wt%). The lower TiO2 content and higher V2O3 content in the MML of the Northern and Western Lobes suggest lower oxidising conditions during the crystallization of oxides. The MML in all three studied lobes consists of two layers of magnetitite, suggesting that MML was formed by two separate magma influxes, probably on a diverse and complex type of magma chamber floor. The high TiO2 content in magnetite, together with the negative correlation between TiO2 and V2O3 suggest that the maximum V content should represent a “less evolved” and less oxidized melt. In this respect, higher concentrations V2O3 in magnetite can be expected in magnetitite layers with lower TiO2. It can be inferred that the Ti-magetite in the MML from the Eastern Lobe was formed from a more evolved (TiO2 and FeO enriched) and more oxidized (lower V2O3) melt, compared with the MML from the Northern and Western lobes. These findings can be used to illustrate: a) that high fO2 can be responsible for the relatively low V content in magnetite from Fe-Ti oxide ores and b) the vanadium in magnetite decreases significantly in more evolved cumulates, due to a decreasing fO2 with differentiation. Compositional profiles of Ti- magnetite along the stratigraphic height of the MML in the Eastern Lobe (composed of two layers, separated in the outcrop by a parting plane) depicts a cryptic variation with depth in each of the two layers, where each layer can be divided into four sublayers, labelled upwards as A, B, C (with C1, C2, C3 and C4) and D based on Cr, Mg, Ti, Al and V variation. Small scale reversals of the mentioned elements and the repetition of A, B, C and D sub-layers in each layer suggest that MML formed from two successive influxes of magma (indicated by relatively elevated values of MgO), which evolved by crystallization and cooling in a similar manner, to produce the A to D variation. Based on these observations and theoretical considerations, this study dismisses several models for the genesis of the MML: the immiscibility, the increased oxygen fugacity, the relative increase of H2O content of the melt, pressure variation within the magma chamber, magma mixing, and crustal rock contamination. The model proposed here for MML genesis involves the crystallization of both Ti-magnetite and ilmenite from a Fe-Ti-Ca-Al-rich melt (ferro-diorite) along its line of descent, and gravitational settling of oxides in a dynamic regime. The factor which triggered the crystallization of magnetite is a critical saturation of melt in magnetite (attaining saturation of magnetite and ilmenite in the melt after some silicates crystallized). The difference between the nature of silicate inclusions in magnetite and the nature of the magnetite floor, suggest that the Fe-rich magma was not in equilibrium with the cumulates from the present floor, but rather it was emplaced laterally on long distances, the melt being disrupted from its own cumulates. The absence of correlation between the Cr2O3 in magnetite and co-existing ilmenite can indicate than no in-situ fractional crystallization took place at the moment of magnetite accumulation, but rather that magnetite and ilmenite gravitationally accumulated and the grains mechanically mixed from a flowing magma. The model presented herein proposes a five stage model of MML formation: Stage 1 is represented by the intrusion of a Fe-T-Ca-Al-rich magma which expands laterally within a flat and thin magma chamber. Oxides start to crystallize within a dynamic regime of the magma. Stage 2 is given by the accumulation of oxides at the bottom of the new floor. Some plagioclase starts to crystallize (e.g. subhedral plagioclase in the MML of the Northern Lobe). Stage 3 is a short living static regime, where both plagioclase and magnetite crystallized, without fractionation, forming the thin magnetite-anorthosite layer separating the MML into two layers. Stage 4 is represented by a new influx of Fe-Ti-Ca-Al-rich magma which is emplaced above the magnetite-bearing anorthosite, flushing out the liquid which was in equilibrium with the anorthosite. The oxides started crystallizing in a dynamic regime, as in Stage 1. In stage 5, the accumulation of oxides produced the upper layer of the MML. Our interpretation is that the flow of the magma was more dynamic (probably more turbulent on long distances) in the MML of the Northern Lobe, compared to the MML in the Western and Eastern lobes, producing highly heterogeneous and imbricated thin layers of magnetitite and silicates. The presence of olivine corona around orthopyroxene suggests the incongruent melting of orthopyroxene, which points out towards a local re-heating of existing silicate layers, this being a strong argument for multiple injections in generation of MML. Massive crystallization of oxides produced the sulphur saturation of the magma and caused the precipitation of the igneous sulphides, which nucleated on the existing oxides. Later hydrothermal fluids (and/or late magmatic volatiles?) percolated the MML, producing chloritization of the included silicates, remobilization of igneous sulphides and precipitation of hydrothermal sulphides.
- Full Text:
- Date Issued: 2017
Evolving an efficient and effective off-the-shelf computing infrastructure for schools in rural areas of South Africa
- Authors: Siebörger, Ingrid Gisélle
- Date: 2017
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/14557 , vital:21938
- Description: Upliftment of rural areas and poverty alleviation are priorities for development in South Africa. Information and knowledge are key strategic resources for social and economic development and ICTs act as tools to support them, enabling innovative and more cost effective approaches. In order for ICT interventions to be possible, infrastructure has to be deployed. For the deployment to be effective and sustainable, the local community needs to be involved in shaping and supporting it. This study describes the technical work done in the Siyakhula Living Lab (SLL), a long-term ICT4D experiment in the Mbashe Municipality, with a focus on the deployment of ICT infrastructure in schools, for teaching and learning but also for use by the communities surrounding the schools. As a result of this work, computing infrastructure was deployed, in various phases, in 17 schools in the area and a “broadband island” connecting them was created. The dissertation reports on the initial deployment phases, discussing theoretical underpinnings and policies for using technology in education as well various computing and networking technologies and associated policies available and appropriate for use in rural South African schools. This information forms the backdrop of a survey conducted with teachers from six schools in the SLL, together with experimental work towards the provision of an evolved, efficient and effective off-the-shelf computing infrastructure in selected schools, in order to attempt to address the shortcomings of the computing infrastructure deployed initially in the SLL. The result of the study is the proposal of an evolved computing infrastructure model for use in rural South African schools.
- Full Text:
- Date Issued: 2017
- Authors: Siebörger, Ingrid Gisélle
- Date: 2017
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/14557 , vital:21938
- Description: Upliftment of rural areas and poverty alleviation are priorities for development in South Africa. Information and knowledge are key strategic resources for social and economic development and ICTs act as tools to support them, enabling innovative and more cost effective approaches. In order for ICT interventions to be possible, infrastructure has to be deployed. For the deployment to be effective and sustainable, the local community needs to be involved in shaping and supporting it. This study describes the technical work done in the Siyakhula Living Lab (SLL), a long-term ICT4D experiment in the Mbashe Municipality, with a focus on the deployment of ICT infrastructure in schools, for teaching and learning but also for use by the communities surrounding the schools. As a result of this work, computing infrastructure was deployed, in various phases, in 17 schools in the area and a “broadband island” connecting them was created. The dissertation reports on the initial deployment phases, discussing theoretical underpinnings and policies for using technology in education as well various computing and networking technologies and associated policies available and appropriate for use in rural South African schools. This information forms the backdrop of a survey conducted with teachers from six schools in the SLL, together with experimental work towards the provision of an evolved, efficient and effective off-the-shelf computing infrastructure in selected schools, in order to attempt to address the shortcomings of the computing infrastructure deployed initially in the SLL. The result of the study is the proposal of an evolved computing infrastructure model for use in rural South African schools.
- Full Text:
- Date Issued: 2017
Experiences of having an adult sibling with a mental illness: an interpretative phenomenological analysis
- Authors: Flannigan, Raylene
- Date: 2017
- Subjects: Mentally ill -- Family relationships , Mentally ill -- Care -- South Africa , Mental illness -- Public opinion -- South Africa , Mentally ill -- Deinstitutionalization , Brothers and sisters of people with disabilities , Brothers and sisters of people with disabilities -- Psycnology , Brothers and sisters of people with disabilities -- Case studies -- South Africa -- Makhanda
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/6309 , vital:21088
- Description: Mental illness has a significant impact on the life of an individual, however not only on the individual but on the family as well. A considerable amount of research has been carried out regarding the experiences of family members internationally. However, in South Africa (SA) there is inadequate information regarding the experiences of families, especially adult siblings, of individuals with a mental illness. Specifically, there is a lack of research investigating individuals’ perceptions of their brother or sister’s mental illness as well as how this affects the sibling relationship. It is for this reason that the current study aimed at exploring the lived experiences of ‘black1’ isiXhosa speaking individuals who have a sibling with a mental illness. The study employed Interpretative Phenomenological Analysis (IPA) as its qualitative approach. A sample of five participants between the ages of 20-50 years was selected through purposive and snowballing sampling techniques. Semi-structured interviews were utilised and were transcribed and analysed based on the IPA framework. The analysis of the participants’ transcripts provided three master themes, which are supported by subordinate themes. The master themes are: 1) experiencing the sibling as a burden post diagnosis, 2) positive experiences from the sibling’s mental illness, 3) participant’s experiences of their sibling’s treatment and the mental health care system. Participants experienced financial burden as well as the burden of caregiving as a result of their sibling’s mental illness; these are understood as being subjective and objective burdens. While no change was experienced within the sibling relationship, the siblings’ mental illness was experienced as affecting the sibling relationship due to the socioeconomic status of the participants and stigma. The findings support and expand on the growing knowledge of adult sibling relationships and mental illness.
- Full Text:
- Date Issued: 2017
- Authors: Flannigan, Raylene
- Date: 2017
- Subjects: Mentally ill -- Family relationships , Mentally ill -- Care -- South Africa , Mental illness -- Public opinion -- South Africa , Mentally ill -- Deinstitutionalization , Brothers and sisters of people with disabilities , Brothers and sisters of people with disabilities -- Psycnology , Brothers and sisters of people with disabilities -- Case studies -- South Africa -- Makhanda
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/6309 , vital:21088
- Description: Mental illness has a significant impact on the life of an individual, however not only on the individual but on the family as well. A considerable amount of research has been carried out regarding the experiences of family members internationally. However, in South Africa (SA) there is inadequate information regarding the experiences of families, especially adult siblings, of individuals with a mental illness. Specifically, there is a lack of research investigating individuals’ perceptions of their brother or sister’s mental illness as well as how this affects the sibling relationship. It is for this reason that the current study aimed at exploring the lived experiences of ‘black1’ isiXhosa speaking individuals who have a sibling with a mental illness. The study employed Interpretative Phenomenological Analysis (IPA) as its qualitative approach. A sample of five participants between the ages of 20-50 years was selected through purposive and snowballing sampling techniques. Semi-structured interviews were utilised and were transcribed and analysed based on the IPA framework. The analysis of the participants’ transcripts provided three master themes, which are supported by subordinate themes. The master themes are: 1) experiencing the sibling as a burden post diagnosis, 2) positive experiences from the sibling’s mental illness, 3) participant’s experiences of their sibling’s treatment and the mental health care system. Participants experienced financial burden as well as the burden of caregiving as a result of their sibling’s mental illness; these are understood as being subjective and objective burdens. While no change was experienced within the sibling relationship, the siblings’ mental illness was experienced as affecting the sibling relationship due to the socioeconomic status of the participants and stigma. The findings support and expand on the growing knowledge of adult sibling relationships and mental illness.
- Full Text:
- Date Issued: 2017
Experiences of pet loss in the South African context
- Authors: Lowen, Kathleen Louise
- Date: 2017
- Subjects: Pet loss -- Psychological aspects , Pet loss -- South Africa -- Case studies , Pets -- Death , Pet ownders -- Psychology , Human-animal relationships -- Psychological aspects , Grief
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/4326 , vital:20649
- Description: In this research the experience of pet loss in relation to the intensity of grief and the repression of that grief due to societal restrictions was studied in a South African sample of 12 pet owners who had experienced the loss of a pet within 24 months prior to the study. A pilot study was conducted in order to refine the semi-structured interview schedule. Participants were asked about their pets, their experience of pet loss in relation to their feelings before and after the loss and whether they felt they could openly grieve around friends and family. The findings indicated that the intensity of grief experienced by the participants was influenced both by the intensity of their Bond with the pet and the repression of their grief due to assumed social sanctions surrounding mourning the loss of a pet. The findings from the study clearly indicate the necessity for pet loss counselling, however it was clear that societal views surrounding pet loss are shifting, thus allowing pet owners to mourn their loss more openly with family and friends. This indicates a decrease in cases of disenfranchised and complicated grief. Furthermore the impact of pet loss necessitates the social legitimation and acknowledgment of the significance of pet loss in contemporary society as these relationships with pets are an increasingly prominent feature both within and as an alternative to familial systems.
- Full Text:
- Date Issued: 2017
- Authors: Lowen, Kathleen Louise
- Date: 2017
- Subjects: Pet loss -- Psychological aspects , Pet loss -- South Africa -- Case studies , Pets -- Death , Pet ownders -- Psychology , Human-animal relationships -- Psychological aspects , Grief
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/4326 , vital:20649
- Description: In this research the experience of pet loss in relation to the intensity of grief and the repression of that grief due to societal restrictions was studied in a South African sample of 12 pet owners who had experienced the loss of a pet within 24 months prior to the study. A pilot study was conducted in order to refine the semi-structured interview schedule. Participants were asked about their pets, their experience of pet loss in relation to their feelings before and after the loss and whether they felt they could openly grieve around friends and family. The findings indicated that the intensity of grief experienced by the participants was influenced both by the intensity of their Bond with the pet and the repression of their grief due to assumed social sanctions surrounding mourning the loss of a pet. The findings from the study clearly indicate the necessity for pet loss counselling, however it was clear that societal views surrounding pet loss are shifting, thus allowing pet owners to mourn their loss more openly with family and friends. This indicates a decrease in cases of disenfranchised and complicated grief. Furthermore the impact of pet loss necessitates the social legitimation and acknowledgment of the significance of pet loss in contemporary society as these relationships with pets are an increasingly prominent feature both within and as an alternative to familial systems.
- Full Text:
- Date Issued: 2017