The enemy release hypothesis and beyond: Lagarosiphon major invasion dynamics and management options for New Zealand using native natural enemies from South Africa
- Authors: Baso, Nompumelelo Catherine
- Date: 2024-04-05
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/435627 , vital:73174 , DOI 10.21504/10962/435627
- Description: Numerous scientific investigations have demonstrated the destructive impact that exotic species can have on ecosystem services beyond a specific threshold. There are many explanations for why introduced plants are likely to be more successful outside their native range. One such explanation is offered by the Enemy Release Hypothesis (ERH), which states that plants automatically become superior competitors outside of their natural range due to release from top-down stressors (herbivory, parasites, and diseases) that is evident in the absence of their natural enemies. The underlying assumption of the ERH is that natural enemies are important regulators of plant species populations, and that the pressures from these natural enemies are felt more readily by native species compared to alien plants. Consequently, in the absence of such pressures, the ERH assumes that exotic plants can allocate more resources towards growth and reproduction, while effectively maintaining accumulated biomass. Classical biological control has previously been cited as evidence for the enemy release hypothesis. Therefore, the overarching aim and theme of this thesis was to investigate the role of ERH on the invasiveness of Lagarosiphon major (Ridl.) Moss ex Wager (Hydrocharitaceae) in New Zealand. Firstly, a literature search and a meta-analysis was used to synthesize existing studies in order to test for general applicability of this hypothesis to aquatic plant invasions. Furthermore, an empirical investigation was conducted in order to directly quantify enemy release in L. major populations invaded areas of New Zealand. To achieve this, various plant parameters of this plant, overall macrophyte and invertebrate diversity were measured and compared between sites in the native range in South Africa and the invaded areas in New Zealand. Although the meta-analysis showed variable evidence for this hypothesis depending on various modulating factors such as study type, plant growth form and measured parameters, for L. major, there was strong evidence of enemy release. The biogeographical comparisons showed that L. major exhibited increased fitness in most of the invaded sites, marked by elevated biomass accumulation, significantly higher shoot production, and the displacement of native plant species. The observed fitness advantages were directly correlated to a decrease in herbivory diversity and pressure upon the plant's introduction to New Zealand. Unlike the native populations, which contend with the presence of at least four co-occurring herbivores, including specialist herbivores, the invaded range had a substantially lower herbivore diversity, with only Hygraula nitens Butler (Lepidoptera: Crambidae) syn. Nymphula nitens, significantly damaging L. major. These findings emphasize the importance of understanding invasion ecology and theories such as ERH in order to advance aquatic plant management and also present valuable insights for developing effective strategies to mitigate the impact of invasive alien species on aquatic ecosystems. Specifically, results from the empirical investigation provide evidence in support of the ERH and highlight the suitability of implementing biological control strategies to manage the L. major invasion in New Zealand. Previous studies have shown the suitability of two specialist herbivores, Hydrellia lagarosiphon Deeming (Diptera: Ephydridae), and Polypedilum tuburcinatum Andersen (Diptera: Chironomidae), as potential biological control agents. This control strategy presents a sustainable and ecologically responsible approach, promoting coexistence between exotic plants and native species rather than displacement through competitive exclusion. With the apparent dominance of L. major at various New Zealand localities, the subsequent objective of this thesis was to investigate the competitive interactions between L. major and another invasive Hydrocharitaceae, Egeria densa Planchon, as driven by herbivory. Combinations of two host specific Ephydrid flies, H. lagarosiphon and H. egeriae, were used at eight different factorial combination of planting densities. The analysis of plant parameters and the application of inverse linear models revealed that L. major often exhibits relatively higher fitness, especially in low monoculture treatments when the two insects were isolated. However, multiple inverse linear models revealed that actual competitive outcomes are dependent on factors such as initial plant density and herbivory regime, with competitive interactions generally being mild. Nevertheless, the presence of H. lagarosiphon resulted in facilitation of E. densa growth. Thus, even at lower densities, these insects still had an impact on the observed interactions, further emphasizing suitability as damaging biological control agents. Lastly, focusing on the abiotic component of L. major invasion, Species Distribution Models (SDMs) were employed to map potential suitable habitat for this species, as well as predict the consequences of climate change on this. Correlative and mechanistic modelling was also used to simulate suitable habitat for potential biological control agents, thus addressing the potential for mismatches between host plant distribution and insect suitable range. The Maximum Entropy Species Distribution Modelling (MaxEnt) algorithm revealed that more than 90% of all freshwater ecosystems in New Zealand are susceptible to L. major invasion, with suitability projected to expand further under future climate scenarios. Moreover, correlative modelling using this method suggests limited suitable habitat for both herbivores. However, degree-day modelling, which also takes into account the physiological requirements, showed that H. lagarosiphon has the potential to produce viable populations in several parts of New Zealand. Overall, this thesis explored the intricate web of biotic and abiotic factors influencing the success of L. major outside its native range. The results emphasize the potential impacts of climate change on the invasion potential and management strategies for L. major. The findings also advocate for the implementation of sustainable and ecologically sound management solutions, such as biological control, to manage this species. , Thesis (PhD) -- Faculty of Science, Botany, 2024
- Full Text:
- Date Issued: 2024-04-05
- Authors: Baso, Nompumelelo Catherine
- Date: 2024-04-05
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/435627 , vital:73174 , DOI 10.21504/10962/435627
- Description: Numerous scientific investigations have demonstrated the destructive impact that exotic species can have on ecosystem services beyond a specific threshold. There are many explanations for why introduced plants are likely to be more successful outside their native range. One such explanation is offered by the Enemy Release Hypothesis (ERH), which states that plants automatically become superior competitors outside of their natural range due to release from top-down stressors (herbivory, parasites, and diseases) that is evident in the absence of their natural enemies. The underlying assumption of the ERH is that natural enemies are important regulators of plant species populations, and that the pressures from these natural enemies are felt more readily by native species compared to alien plants. Consequently, in the absence of such pressures, the ERH assumes that exotic plants can allocate more resources towards growth and reproduction, while effectively maintaining accumulated biomass. Classical biological control has previously been cited as evidence for the enemy release hypothesis. Therefore, the overarching aim and theme of this thesis was to investigate the role of ERH on the invasiveness of Lagarosiphon major (Ridl.) Moss ex Wager (Hydrocharitaceae) in New Zealand. Firstly, a literature search and a meta-analysis was used to synthesize existing studies in order to test for general applicability of this hypothesis to aquatic plant invasions. Furthermore, an empirical investigation was conducted in order to directly quantify enemy release in L. major populations invaded areas of New Zealand. To achieve this, various plant parameters of this plant, overall macrophyte and invertebrate diversity were measured and compared between sites in the native range in South Africa and the invaded areas in New Zealand. Although the meta-analysis showed variable evidence for this hypothesis depending on various modulating factors such as study type, plant growth form and measured parameters, for L. major, there was strong evidence of enemy release. The biogeographical comparisons showed that L. major exhibited increased fitness in most of the invaded sites, marked by elevated biomass accumulation, significantly higher shoot production, and the displacement of native plant species. The observed fitness advantages were directly correlated to a decrease in herbivory diversity and pressure upon the plant's introduction to New Zealand. Unlike the native populations, which contend with the presence of at least four co-occurring herbivores, including specialist herbivores, the invaded range had a substantially lower herbivore diversity, with only Hygraula nitens Butler (Lepidoptera: Crambidae) syn. Nymphula nitens, significantly damaging L. major. These findings emphasize the importance of understanding invasion ecology and theories such as ERH in order to advance aquatic plant management and also present valuable insights for developing effective strategies to mitigate the impact of invasive alien species on aquatic ecosystems. Specifically, results from the empirical investigation provide evidence in support of the ERH and highlight the suitability of implementing biological control strategies to manage the L. major invasion in New Zealand. Previous studies have shown the suitability of two specialist herbivores, Hydrellia lagarosiphon Deeming (Diptera: Ephydridae), and Polypedilum tuburcinatum Andersen (Diptera: Chironomidae), as potential biological control agents. This control strategy presents a sustainable and ecologically responsible approach, promoting coexistence between exotic plants and native species rather than displacement through competitive exclusion. With the apparent dominance of L. major at various New Zealand localities, the subsequent objective of this thesis was to investigate the competitive interactions between L. major and another invasive Hydrocharitaceae, Egeria densa Planchon, as driven by herbivory. Combinations of two host specific Ephydrid flies, H. lagarosiphon and H. egeriae, were used at eight different factorial combination of planting densities. The analysis of plant parameters and the application of inverse linear models revealed that L. major often exhibits relatively higher fitness, especially in low monoculture treatments when the two insects were isolated. However, multiple inverse linear models revealed that actual competitive outcomes are dependent on factors such as initial plant density and herbivory regime, with competitive interactions generally being mild. Nevertheless, the presence of H. lagarosiphon resulted in facilitation of E. densa growth. Thus, even at lower densities, these insects still had an impact on the observed interactions, further emphasizing suitability as damaging biological control agents. Lastly, focusing on the abiotic component of L. major invasion, Species Distribution Models (SDMs) were employed to map potential suitable habitat for this species, as well as predict the consequences of climate change on this. Correlative and mechanistic modelling was also used to simulate suitable habitat for potential biological control agents, thus addressing the potential for mismatches between host plant distribution and insect suitable range. The Maximum Entropy Species Distribution Modelling (MaxEnt) algorithm revealed that more than 90% of all freshwater ecosystems in New Zealand are susceptible to L. major invasion, with suitability projected to expand further under future climate scenarios. Moreover, correlative modelling using this method suggests limited suitable habitat for both herbivores. However, degree-day modelling, which also takes into account the physiological requirements, showed that H. lagarosiphon has the potential to produce viable populations in several parts of New Zealand. Overall, this thesis explored the intricate web of biotic and abiotic factors influencing the success of L. major outside its native range. The results emphasize the potential impacts of climate change on the invasion potential and management strategies for L. major. The findings also advocate for the implementation of sustainable and ecologically sound management solutions, such as biological control, to manage this species. , Thesis (PhD) -- Faculty of Science, Botany, 2024
- Full Text:
- Date Issued: 2024-04-05
The impacts of bottom-up and top-down drivers in shaping the herbivore community in Pafuri, Kruger National Park, South Africa
- Authors: Walker, Gareth Alexander
- Date: 2024-04-05
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/435703 , vital:73180 , DOI 10.21504/10962/435703
- Description: Globally, terrestrial mammal populations are facing critical population declines and range contractions owing to habitat fragmentation and destruction, wildlife overexploitation, and climate change driven by expansion of the human population. Mammalian herbivores are integral for maintaining ecosystem structure and functionality. They do this this through herbivory, by acting as prey and cycling soil nutrients. The impacts of herbivores on ecosystems, however, vary with their spatial occupancy which is influenced by interacting bottom-up and top-down factors. Modelling the drivers of herbivore communities is no trivial task given the myriad of potential bottom-up and top-down factors, and the interactions between the two, as well as the species-specific variations in intrinsic functional traits (e.g., foraging strategy, body size, metabolic rate, etc.) influencing herbivore responses (e.g., social structure, space-use, activity patterns, etc.) to these drivers. Consequently, few studies have attempted to model both bottom-up and top-down drivers in structuring herbivore communities, particularly in an African context where predator-prey guilds include multiple species, exposed to high levels of human activity. Therefore, the overarching aim of my research was to quantify the relative effects of both bottom-up and top-down factors driving the herbivore community in the northern Pafuri region of Kruger National Park, South Africa. I utilized a combination of field (i.e., camera trap and vegetation surveys) and analytical (i.e., stable carbon isotopes from faeces and plants) techniques in conjunction with geospatial data to evaluate the impacts of bottom-up (i.e., forage quantity, quality, and water availability) and top-down (i.e., predation and anthropogenic risks) factors on herbivore spatial occupancy and activity patterns. Herbivore responses to bottom-up and top-down factors were species-specific, even among members of the same feeding guild. Specifically, I found that herbivores (varying in body size and foraging strategy) displayed temporal, spatial and in some instances, dietary shifts that reflect species-specific, ecological trade-offs between resource acquisition, and predator and human avoidance. For example, kudu (Tragelaphus strepsiceros) displayed temporal and spatial avoidance of predators and humans, and exhibited previously undocumented levels of seasonal dietary shifts which suggests that the species traded forage acquisition for reduced predation and anthropogenic risks. Further, high levels of human activity appeared to eclipse the risks associated with natural predators resulting in human induced landscapes of fear. For example, warthogs (Phacochoerus africanus) and zebra (Equus quagga) occupied habitats with higher predation risks, but displayed spatial avoidance of nature reserve boundaries which were synonymous with high levels of bushmeat poaching. Most studies focussing on the impacts of bottom-up and top-down drivers neglect to consider the roles that humans play in structuring ecological communities. The results of my thesis, however, emphasize the importance of including anthropogenic drivers when investigating the roles that various bottom-up and top-down factors play in shaping ecological communities. , Thesis (PhD) -- Faculty of Science, Zoology and Entomology, 2024
- Full Text:
- Date Issued: 2024-04-05
- Authors: Walker, Gareth Alexander
- Date: 2024-04-05
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/435703 , vital:73180 , DOI 10.21504/10962/435703
- Description: Globally, terrestrial mammal populations are facing critical population declines and range contractions owing to habitat fragmentation and destruction, wildlife overexploitation, and climate change driven by expansion of the human population. Mammalian herbivores are integral for maintaining ecosystem structure and functionality. They do this this through herbivory, by acting as prey and cycling soil nutrients. The impacts of herbivores on ecosystems, however, vary with their spatial occupancy which is influenced by interacting bottom-up and top-down factors. Modelling the drivers of herbivore communities is no trivial task given the myriad of potential bottom-up and top-down factors, and the interactions between the two, as well as the species-specific variations in intrinsic functional traits (e.g., foraging strategy, body size, metabolic rate, etc.) influencing herbivore responses (e.g., social structure, space-use, activity patterns, etc.) to these drivers. Consequently, few studies have attempted to model both bottom-up and top-down drivers in structuring herbivore communities, particularly in an African context where predator-prey guilds include multiple species, exposed to high levels of human activity. Therefore, the overarching aim of my research was to quantify the relative effects of both bottom-up and top-down factors driving the herbivore community in the northern Pafuri region of Kruger National Park, South Africa. I utilized a combination of field (i.e., camera trap and vegetation surveys) and analytical (i.e., stable carbon isotopes from faeces and plants) techniques in conjunction with geospatial data to evaluate the impacts of bottom-up (i.e., forage quantity, quality, and water availability) and top-down (i.e., predation and anthropogenic risks) factors on herbivore spatial occupancy and activity patterns. Herbivore responses to bottom-up and top-down factors were species-specific, even among members of the same feeding guild. Specifically, I found that herbivores (varying in body size and foraging strategy) displayed temporal, spatial and in some instances, dietary shifts that reflect species-specific, ecological trade-offs between resource acquisition, and predator and human avoidance. For example, kudu (Tragelaphus strepsiceros) displayed temporal and spatial avoidance of predators and humans, and exhibited previously undocumented levels of seasonal dietary shifts which suggests that the species traded forage acquisition for reduced predation and anthropogenic risks. Further, high levels of human activity appeared to eclipse the risks associated with natural predators resulting in human induced landscapes of fear. For example, warthogs (Phacochoerus africanus) and zebra (Equus quagga) occupied habitats with higher predation risks, but displayed spatial avoidance of nature reserve boundaries which were synonymous with high levels of bushmeat poaching. Most studies focussing on the impacts of bottom-up and top-down drivers neglect to consider the roles that humans play in structuring ecological communities. The results of my thesis, however, emphasize the importance of including anthropogenic drivers when investigating the roles that various bottom-up and top-down factors play in shaping ecological communities. , Thesis (PhD) -- Faculty of Science, Zoology and Entomology, 2024
- Full Text:
- Date Issued: 2024-04-05
The influence of the physical environment on invertebrate larval transport, settlement and recruitment with insights on early-stage physiological performance
- Authors: Duna, Oliver Olwethu
- Date: 2024-04-05
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/435663 , vital:73177 , DOI 10.21504/10962/435663
- Description: Most marine benthic organisms have a biphasic life cycle whereby the larvae are pelagic, and their distribution, transport and settlement are largely controlled by environmental factors. Among these factors, hydrodynamics have key direct effects. Nearshore water hydrodynamics are strongly influenced by wind. This study investigated whether wind indirectly affects the distribution, settlement and recruitment of invertebrate marine larvae. Additionally, larvae are exposed to a more constant, benign environment than they will experience after settlement, and therefore the possible effects of larval thermal history on the physiological plasticity of settled organisms was also estimated for possible long-term insights into population dynamics. Four sites, two on the western and two on the eastern side of Algoa Bay in Gqeberha (formerly known as Port Elizabeth), South Africa, were chosen for larval collection. Sites at opposite ends of the bay were selected as they were towards either side of the dominant wind directions in this region. At each site, two sampling stations were identified at 300 and 900 metres offshore, with station replicates 300 metres apart. Sampling of marine invertebrate larvae was conducted after two days of westerly or easterly winds at either of the two western or eastern sites. The number of hours of unidirectional wind determined the prevalent wind on the two days prior to sampling. Samples were collected with a plankton pump at three depths; surface, mid-depth and bottom. Simultaneously with plankton sampling, water properties (fluorescence, temperature, zonal and meridional flow, salinity and oxygen) were measured. Settlement/recruitment samples of mussels and barnacles were collected at six sites, two at either edge of the bay and two within the center of the bay. Plastic scouring pads and PVC plastic plates covered with safety-walk, placed at least 30 cm from each other, were used to collect settlers/recruits of mussels and barnacles, respectively. The pads and plates were replaced on a monthly basis for 14 months to quantify monthly settlement/recruitment. At four of the six sites used for quantifying settlement/recruitment, settlers and recruits were collected to measure the physiological responses of these two ontogenetic stages (settlers and recruits) to acute temperature variations which they might experience in the intertidal zone. Three temperature loggers were used to record real time temperature variation at each site over the period (one month) in which the artificial collectors were in position. Factorial ANOVA was used to investigate the effects of wind, depth, site, and distance from the shore on the abundance of larvae in the water column, as well as the effects of month and site on settlement/recruitment. Additionally, multiple regression analyses were used to investigate the effects of physical parameters, including upwelling and dissipation of turbulent kinetic energy, on the abundance of both larvae, settlers and recruits. Distance-based linear models and redundancy analyses were also carried out on the abundances of invertebrate larvae. Correlation analyses were performed to investigate the effect of the number of hours of directional wind on settlement. Lastly, correlation analyses between wind and currents were carried out. The results revealed a link between winds and currents, with wind speed directly proportional to surface current speed, which, as expected, decreased with depth. Current direction was, however, not perfectly aligned with wind direction. Larval distribution, settlement and recruitment were largely associated with the nearshore dissipation of turbulent kinetic energy and upwelling. Thus, overall larval, settler and recruit abundances were indirectly affected by wind. Physiologically, there was no significant difference in oxygen consumption between the juvenile ontogenetic stages (settlers and recruits) of mussels. Recruits exposed to average and maximum temperatures, however, consumed more oxygen than those exposed to low temperatures. Wind and wind-mediated currents as well as temperature have been shown to shape the distribution and shore supply of larvae, and this study contributes to the broad knowledge of population dynamics and replenishment, and the tight relation of abiotic factors affecting biological processes on the shore. , Thesis (PhD) -- Faculty of Science, Zoology and Entomology, 2024
- Full Text:
- Date Issued: 2024-04-05
- Authors: Duna, Oliver Olwethu
- Date: 2024-04-05
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/435663 , vital:73177 , DOI 10.21504/10962/435663
- Description: Most marine benthic organisms have a biphasic life cycle whereby the larvae are pelagic, and their distribution, transport and settlement are largely controlled by environmental factors. Among these factors, hydrodynamics have key direct effects. Nearshore water hydrodynamics are strongly influenced by wind. This study investigated whether wind indirectly affects the distribution, settlement and recruitment of invertebrate marine larvae. Additionally, larvae are exposed to a more constant, benign environment than they will experience after settlement, and therefore the possible effects of larval thermal history on the physiological plasticity of settled organisms was also estimated for possible long-term insights into population dynamics. Four sites, two on the western and two on the eastern side of Algoa Bay in Gqeberha (formerly known as Port Elizabeth), South Africa, were chosen for larval collection. Sites at opposite ends of the bay were selected as they were towards either side of the dominant wind directions in this region. At each site, two sampling stations were identified at 300 and 900 metres offshore, with station replicates 300 metres apart. Sampling of marine invertebrate larvae was conducted after two days of westerly or easterly winds at either of the two western or eastern sites. The number of hours of unidirectional wind determined the prevalent wind on the two days prior to sampling. Samples were collected with a plankton pump at three depths; surface, mid-depth and bottom. Simultaneously with plankton sampling, water properties (fluorescence, temperature, zonal and meridional flow, salinity and oxygen) were measured. Settlement/recruitment samples of mussels and barnacles were collected at six sites, two at either edge of the bay and two within the center of the bay. Plastic scouring pads and PVC plastic plates covered with safety-walk, placed at least 30 cm from each other, were used to collect settlers/recruits of mussels and barnacles, respectively. The pads and plates were replaced on a monthly basis for 14 months to quantify monthly settlement/recruitment. At four of the six sites used for quantifying settlement/recruitment, settlers and recruits were collected to measure the physiological responses of these two ontogenetic stages (settlers and recruits) to acute temperature variations which they might experience in the intertidal zone. Three temperature loggers were used to record real time temperature variation at each site over the period (one month) in which the artificial collectors were in position. Factorial ANOVA was used to investigate the effects of wind, depth, site, and distance from the shore on the abundance of larvae in the water column, as well as the effects of month and site on settlement/recruitment. Additionally, multiple regression analyses were used to investigate the effects of physical parameters, including upwelling and dissipation of turbulent kinetic energy, on the abundance of both larvae, settlers and recruits. Distance-based linear models and redundancy analyses were also carried out on the abundances of invertebrate larvae. Correlation analyses were performed to investigate the effect of the number of hours of directional wind on settlement. Lastly, correlation analyses between wind and currents were carried out. The results revealed a link between winds and currents, with wind speed directly proportional to surface current speed, which, as expected, decreased with depth. Current direction was, however, not perfectly aligned with wind direction. Larval distribution, settlement and recruitment were largely associated with the nearshore dissipation of turbulent kinetic energy and upwelling. Thus, overall larval, settler and recruit abundances were indirectly affected by wind. Physiologically, there was no significant difference in oxygen consumption between the juvenile ontogenetic stages (settlers and recruits) of mussels. Recruits exposed to average and maximum temperatures, however, consumed more oxygen than those exposed to low temperatures. Wind and wind-mediated currents as well as temperature have been shown to shape the distribution and shore supply of larvae, and this study contributes to the broad knowledge of population dynamics and replenishment, and the tight relation of abiotic factors affecting biological processes on the shore. , Thesis (PhD) -- Faculty of Science, Zoology and Entomology, 2024
- Full Text:
- Date Issued: 2024-04-05
Wild edible plants in rural home gardens: livelihoods, perceptions, economic value & traditional knowledge
- Authors: Mothupi, Frans Makwena
- Date: 2024-04-05
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/435885 , vital:73209 , DOI 10.21504/10962/435885
- Description: The prevalence of hunger and malnutrition has been steadily increasing in the world over the past decades. The rate of food insecurity was further exacerbated by the COVID 19 pandemic which plunged millions more into hunger as a result of a recovering economy and high food prices. These challenges are mostly experienced in Africa and are estimated to worsen in this region already affected by conflict, poor healthcare, and natural disasters such as floods and droughts. The green revolution in the 1960’s elevated agricultural production to play a pivotal role in the provision of food. However, production focused mainly on the cultivation of staple crops such as rice, wheat, and maize. The reliance on these crops has contributed to the lack of micronutrient intake and consumption of non-diverse diets. Wild edible plants (WEPs) which previously formed a significant part of indigenous people’s diet, have been regarded as an important food source crucial for the alleviation of malnutrition and micronutrient deficiencies. Despite their nutritional qualities, they are often ignored, overlooked, and undermined by agricultural programmes and food security interventions. Additionally, WEPs are largely absent in modern diets, they are often surrounded by negative perceptions, they are economically undervalued, and the indigenous knowledge of these species is under threat. As a result, this study regards WEPs as important resources that can significantly contribute to improved livelihood outcomes such as income, food security and good health. Using the Sustainable Livelihoods Framework, this study evaluated the contribution of WEPs to sustaining livelihoods, providing economic value, and examined how WEPs are perceived as well as the relationship between their knowledge and consumption in rural areas. This study was conducted in rural villages that are under the jurisdiction of the Moletjie and Matlala tribal authorities in the Polokwane and Aganang local municipalities, South Africa. Qualitative and quantitative research methods were employed for data collection. A total of 356 participants were interviewed for this study. Firstly, in-depth interviews were conducted with 20 elderly participants (Chapter 2). Semi-structured interviews were conducted with a total of 120 participants stratified by age, gender, and income groups (Chapter 3). A total of 96 household surveys were conducted in selected villages, this was complemented by direct observations and field surveys of the home gardens (Chapter 4). Questionnaires and freelists were administered to a total of 120 participants also stratified by age, gender, and income groups to collect data on indigenous knowledge of WEPs (Chapter 5). Thematic analysis were performed for interview data (Chapter 2) and data were summarised, descriptive statistics, chi square tests (Chapter 3), Kruskal-Wallis tests (Chapter 4), ANOVA tests and correlation tests (Chapter 5) were performed using SPSS software. The findings show that there has been a major nutrition transition characterised by changed meal composition, patterns, and frequency relating to the consumption of WEPs. The changes can be attributed to increasing western influence characterised by rising urbanisation, western lifestyle of church, school, and employment in an income-based economy dependent on retail stores to fulfil their daily dietary needs. Despite this, WEPs are still valuable to rural people, this is indicated by the fact that traditional foods are made optional at some modern and traditional celebrations. Overall, most of perceptions (65.6%) regarding the consumption of WEPs were positive. The overwhelming majority of respondents agreed or strongly agreed that preparations from the local WEPs are relatively more tasty (98.3%), healthy (96.6%), nutritious (86.7%), and better represent the traditional foods (94.1%). Additionally, participants perceived WEPs to have health benefits in that they have medicinal properties to help prevent diseases, are a good source of energy, highly nutritious and they give strength. Despite these benefits and positive perceptions, most participants expressed doubt over the commercial success of WEPs if they were to compete with cultivated crops in the market. As a result, they perceive the future of WEPs to be bleak as 95% of participants believe that their consumption is in decline. This can be largely attributed to deagrarianisation, climate change, and preference of cultivated foods by the youth. The study also showed that a diversity fruits and vegetables are available in rural home gardens, with cultivated fruits grown in abundance and WEPs available in almost all households (98%). WEPs represented 34% of the total estimated economic value of plants available in rural home gardens. Most of the home gardens produce food to supplement household food supply with only a few households engaged in trading. The trading of WEPs was recorded in 9% of the home gardens while 16% sold cultivated fruits and/or vegetables. Challenges such as lack of water and poor rainfall are shocks which affect the availability, richness, and abundance of home garden produce. WEPs are generally well known in rural areas as participants listed an average of 8.4±2.4 species. There was a significant statistical difference between the number of species listed by age group (p = 0.009) with the elderly listing a higher average number of species (9.3±2.6) compared to adults (8.1±2.5) and the youth (7.8±1.7). Vangueria infausta, Sclerocarya caffra, Ximenia caffra, Amaranthus retroflexus L. retroflexus, Citrullus lanatus,and Cleome gynadra where among the top listed species. There was also a significant positive correlation between the number of listed fruits with number of listed vegetables. The study also found a positive correlation between knowledge of WEPs and consumption. Most of the knowledge about WEPs was learned from a family member (89%), own observation (86%), a village elder (75%). This knowledge was mostly acquired from childhood through oral tradition (63%) and through participation (21%), and consumption (12%). , Thesis (PhD) -- Faculty of Science, Environmental Science, 2024
- Full Text:
- Date Issued: 2024-04-05
- Authors: Mothupi, Frans Makwena
- Date: 2024-04-05
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/435885 , vital:73209 , DOI 10.21504/10962/435885
- Description: The prevalence of hunger and malnutrition has been steadily increasing in the world over the past decades. The rate of food insecurity was further exacerbated by the COVID 19 pandemic which plunged millions more into hunger as a result of a recovering economy and high food prices. These challenges are mostly experienced in Africa and are estimated to worsen in this region already affected by conflict, poor healthcare, and natural disasters such as floods and droughts. The green revolution in the 1960’s elevated agricultural production to play a pivotal role in the provision of food. However, production focused mainly on the cultivation of staple crops such as rice, wheat, and maize. The reliance on these crops has contributed to the lack of micronutrient intake and consumption of non-diverse diets. Wild edible plants (WEPs) which previously formed a significant part of indigenous people’s diet, have been regarded as an important food source crucial for the alleviation of malnutrition and micronutrient deficiencies. Despite their nutritional qualities, they are often ignored, overlooked, and undermined by agricultural programmes and food security interventions. Additionally, WEPs are largely absent in modern diets, they are often surrounded by negative perceptions, they are economically undervalued, and the indigenous knowledge of these species is under threat. As a result, this study regards WEPs as important resources that can significantly contribute to improved livelihood outcomes such as income, food security and good health. Using the Sustainable Livelihoods Framework, this study evaluated the contribution of WEPs to sustaining livelihoods, providing economic value, and examined how WEPs are perceived as well as the relationship between their knowledge and consumption in rural areas. This study was conducted in rural villages that are under the jurisdiction of the Moletjie and Matlala tribal authorities in the Polokwane and Aganang local municipalities, South Africa. Qualitative and quantitative research methods were employed for data collection. A total of 356 participants were interviewed for this study. Firstly, in-depth interviews were conducted with 20 elderly participants (Chapter 2). Semi-structured interviews were conducted with a total of 120 participants stratified by age, gender, and income groups (Chapter 3). A total of 96 household surveys were conducted in selected villages, this was complemented by direct observations and field surveys of the home gardens (Chapter 4). Questionnaires and freelists were administered to a total of 120 participants also stratified by age, gender, and income groups to collect data on indigenous knowledge of WEPs (Chapter 5). Thematic analysis were performed for interview data (Chapter 2) and data were summarised, descriptive statistics, chi square tests (Chapter 3), Kruskal-Wallis tests (Chapter 4), ANOVA tests and correlation tests (Chapter 5) were performed using SPSS software. The findings show that there has been a major nutrition transition characterised by changed meal composition, patterns, and frequency relating to the consumption of WEPs. The changes can be attributed to increasing western influence characterised by rising urbanisation, western lifestyle of church, school, and employment in an income-based economy dependent on retail stores to fulfil their daily dietary needs. Despite this, WEPs are still valuable to rural people, this is indicated by the fact that traditional foods are made optional at some modern and traditional celebrations. Overall, most of perceptions (65.6%) regarding the consumption of WEPs were positive. The overwhelming majority of respondents agreed or strongly agreed that preparations from the local WEPs are relatively more tasty (98.3%), healthy (96.6%), nutritious (86.7%), and better represent the traditional foods (94.1%). Additionally, participants perceived WEPs to have health benefits in that they have medicinal properties to help prevent diseases, are a good source of energy, highly nutritious and they give strength. Despite these benefits and positive perceptions, most participants expressed doubt over the commercial success of WEPs if they were to compete with cultivated crops in the market. As a result, they perceive the future of WEPs to be bleak as 95% of participants believe that their consumption is in decline. This can be largely attributed to deagrarianisation, climate change, and preference of cultivated foods by the youth. The study also showed that a diversity fruits and vegetables are available in rural home gardens, with cultivated fruits grown in abundance and WEPs available in almost all households (98%). WEPs represented 34% of the total estimated economic value of plants available in rural home gardens. Most of the home gardens produce food to supplement household food supply with only a few households engaged in trading. The trading of WEPs was recorded in 9% of the home gardens while 16% sold cultivated fruits and/or vegetables. Challenges such as lack of water and poor rainfall are shocks which affect the availability, richness, and abundance of home garden produce. WEPs are generally well known in rural areas as participants listed an average of 8.4±2.4 species. There was a significant statistical difference between the number of species listed by age group (p = 0.009) with the elderly listing a higher average number of species (9.3±2.6) compared to adults (8.1±2.5) and the youth (7.8±1.7). Vangueria infausta, Sclerocarya caffra, Ximenia caffra, Amaranthus retroflexus L. retroflexus, Citrullus lanatus,and Cleome gynadra where among the top listed species. There was also a significant positive correlation between the number of listed fruits with number of listed vegetables. The study also found a positive correlation between knowledge of WEPs and consumption. Most of the knowledge about WEPs was learned from a family member (89%), own observation (86%), a village elder (75%). This knowledge was mostly acquired from childhood through oral tradition (63%) and through participation (21%), and consumption (12%). , Thesis (PhD) -- Faculty of Science, Environmental Science, 2024
- Full Text:
- Date Issued: 2024-04-05
Case in modern standard Arabic
- Ghammaz, Hamzah Saleh Theyab
- Authors: Ghammaz, Hamzah Saleh Theyab
- Date: 2024-04-04
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/435593 , vital:73171 , DOI 10.21504/10962/435593
- Description: This thesis provides a novel account of case checking in Modern Standard Arabic (henceforth MSA). It argues against the concept that nominative case in topic and comment structures is default. Default or inherent case is not related to case filter, nor is it assigned by any syntactic method. Some linguists claim that the default case in Arabic language is employed only when no case assigner is available. I argue, in light of the minimalist program (henceforth MP), that default (inherent) case is always a problem for syntactic theory and that the nominative case which the topic and comment sentences bear is valued by a functional head. The topic and comment constructions contain a predicational head (Pred)- a functional head, that is equivalent to vP which occurs in verbal constructions. The head of PredP is accountable for nominative case value on the topic and comment structures. This thesis also provides a novel paradigm regarding the clitics that appear at the end of verbs in MSA. This paradigm proves that these clitics are not agreement, tense, nor mood markers but rather Verbal Case markers and it provides a minimalist program account to explain case checking on verbs in MSA. Regarding sentence initial DP, and contra to the proposal that in SVO sentence initial DP is a subject, I have scrutinised the nature of this DP and provided enough evidence that it is a topic. Additionally, I have investigated the relationship between agreement asymmetry and the position of the subject in MSA from the minimalist feature inheritance account viewpoint. Mainly, I reviewed null pro hypothesis which proved to be redundant to account for the derivation of VSO or SVO word orders. I have also proved what were considered agreement markers are not agreement markers but resumptive pronouns. Finally, I proved that there is not agreement asymmetry in MSA. Agreement pattern in MSA results from the agree operation and it is achieved under Probe-Goal alignment; regardless of whether the Goal is raised up to Spec-TP or remains in situ (Spec-VP), the agreement is not supposed to change. This conclusion is in harmony with the principles of MP Agree Theory. , Thesis (PhD) -- Humanities, Linguistics and Applied Language Studies, 2024
- Full Text:
- Date Issued: 2024-04-04
- Authors: Ghammaz, Hamzah Saleh Theyab
- Date: 2024-04-04
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/435593 , vital:73171 , DOI 10.21504/10962/435593
- Description: This thesis provides a novel account of case checking in Modern Standard Arabic (henceforth MSA). It argues against the concept that nominative case in topic and comment structures is default. Default or inherent case is not related to case filter, nor is it assigned by any syntactic method. Some linguists claim that the default case in Arabic language is employed only when no case assigner is available. I argue, in light of the minimalist program (henceforth MP), that default (inherent) case is always a problem for syntactic theory and that the nominative case which the topic and comment sentences bear is valued by a functional head. The topic and comment constructions contain a predicational head (Pred)- a functional head, that is equivalent to vP which occurs in verbal constructions. The head of PredP is accountable for nominative case value on the topic and comment structures. This thesis also provides a novel paradigm regarding the clitics that appear at the end of verbs in MSA. This paradigm proves that these clitics are not agreement, tense, nor mood markers but rather Verbal Case markers and it provides a minimalist program account to explain case checking on verbs in MSA. Regarding sentence initial DP, and contra to the proposal that in SVO sentence initial DP is a subject, I have scrutinised the nature of this DP and provided enough evidence that it is a topic. Additionally, I have investigated the relationship between agreement asymmetry and the position of the subject in MSA from the minimalist feature inheritance account viewpoint. Mainly, I reviewed null pro hypothesis which proved to be redundant to account for the derivation of VSO or SVO word orders. I have also proved what were considered agreement markers are not agreement markers but resumptive pronouns. Finally, I proved that there is not agreement asymmetry in MSA. Agreement pattern in MSA results from the agree operation and it is achieved under Probe-Goal alignment; regardless of whether the Goal is raised up to Spec-TP or remains in situ (Spec-VP), the agreement is not supposed to change. This conclusion is in harmony with the principles of MP Agree Theory. , Thesis (PhD) -- Humanities, Linguistics and Applied Language Studies, 2024
- Full Text:
- Date Issued: 2024-04-04
Ingqiqo yamanina kuxanduva lokusiphula neengcambu ugonyamelo nokuxhatshazwa: Uhlalutyo lweetekisi ZesiXhosa ezicatshulwe kuncwadi olubhalwe ngamanina (1976-2015)
- Authors: Bilatyi, Katy Nomthandazo
- Date: 2024-04-04
- Subjects: Uncatalogued
- Language: Xhosa
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/435582 , vital:73170 , DOI 10.21504/10962/435582
- Description: Uphando luza kuqwalasela ingqiqo yamanina kuxanduva lokusiphula neengcambu ugonyamelo nokuxhatshazwa kwawo ngamadoda. Ingxoxo iza kugxila kubabhali abangamanina beencwadi zesiXhosa ezicatshulweyo kolu phando, nalapho kuqwalaselwa indlela ababazoba ngayo abalinganiswa babo abangamanina. Kule ngxoxo kuqwalaselwa indlela ababhali abangamanina abafana noBelebesi (1976), Dazela (1988), Magadla (1992) Madolo (1998), Mayosi (2003), Magqashela (2006) kunye noBuzani (2015) abathe babazoba ngayo abalinganiswa abangamanina kwiincwadi zesiXhosa ezicatshuliweyo. Oku kukutyhila ubukrelekrele bababhali ekusebenziseni uncwadi ukuzisa izisombululo kwimingeni ajamelene nayo amanina efana nogonyamelo kunye noxhatshwazo. Obu bukrelekrele baba babhali bujongwa ngokweembali ezimbini, imbali yaphambi kozuzo lwenkululeko emva kongenelelo lobuKoloniyali kunye neyasemva kozuzo lwenkululeko yaseMzantsi Afrika. Iincwadi ezikhethiweyo zibhalwe phakathi kweminyaka ye-1976 ukuya kwiminyaka yama-2015. Uphando luya kujonga ukuba lungaba lukhona utshintsho kusini na kwindlela la manina ababazoba ngayo abalinganiswa ngokwezi mbali zahlukileyo kananjalo naxa bezotywa ngababhali abangamadoda. Uphando luya kutyhila kananjalo imixholo nemixholwana abayikhethayo nedlulisa iimvakalelo zabo bengamanina kumbandela wogonyamelo olukhatshwa yipatriyakhi kunye noxhatshazo abalufumana kumadoda. Xa kuphendlwa le mixholo yaba babhali bahlukileyo baneemvelaphi ezahlukileyo ngokwemontlalo bebhala ngokwamaxesha okanye iimbhali ezahlukileyo, kuya kucaca ukuba amava abo ayafana nokuba linina okanye ibhinqa. Loo mava abo anele ukuba bajikeleze kwimixholo ebizwa ngokuba yifeminist themes nakubeni izimbo zabo zokubhala zahlukile nje. Injongo kukubonisa ukuba nangona amanina aphila phantsi kweemeko neemontlalo ezahlukileyo nje, iinzima neentlungu zawo azisombulula ngendlela efanayo ngokusebenzisa usiba. Le ngxoxo ikhatshwa ziithiyori ezifana nefemayinizimu, ngakumbi ifemayinizimu yaseAfrika kunye kunye nangokoMzantsi Afrika iquka iMotherism kunye nenkcubeko ephehlelelwe phantsi kwePatriyakhi. Ezi thiyori ziludondolo lokuphendla nokuhlalutya ezi ncwadi zikhethiweyo zesiXhosa ukuze sicacelwe yeyona ndima idlalwa ngamanina kuluntu nanjengoko sisazi ukuba apha eMzantsi Afrika adlale eyona ndima yokuncedisa ekuziseni utshintsho kwimibandela yengcinezelo nasekuzuzweni kwenkululeko. Yiyo loo nto kufuneka nawo abonakale exhamla ngokulinganayo namadoda kwinkululeko ayisebenzeleyo ngokususa ugonyamelo, uxhatshazo nokubulawa kwawo ngamadoda. , Thesis (PhD) -- Humanities, School of Languages and Literatures, 2024
- Full Text:
- Date Issued: 2024-04-04
- Authors: Bilatyi, Katy Nomthandazo
- Date: 2024-04-04
- Subjects: Uncatalogued
- Language: Xhosa
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/435582 , vital:73170 , DOI 10.21504/10962/435582
- Description: Uphando luza kuqwalasela ingqiqo yamanina kuxanduva lokusiphula neengcambu ugonyamelo nokuxhatshazwa kwawo ngamadoda. Ingxoxo iza kugxila kubabhali abangamanina beencwadi zesiXhosa ezicatshulweyo kolu phando, nalapho kuqwalaselwa indlela ababazoba ngayo abalinganiswa babo abangamanina. Kule ngxoxo kuqwalaselwa indlela ababhali abangamanina abafana noBelebesi (1976), Dazela (1988), Magadla (1992) Madolo (1998), Mayosi (2003), Magqashela (2006) kunye noBuzani (2015) abathe babazoba ngayo abalinganiswa abangamanina kwiincwadi zesiXhosa ezicatshuliweyo. Oku kukutyhila ubukrelekrele bababhali ekusebenziseni uncwadi ukuzisa izisombululo kwimingeni ajamelene nayo amanina efana nogonyamelo kunye noxhatshwazo. Obu bukrelekrele baba babhali bujongwa ngokweembali ezimbini, imbali yaphambi kozuzo lwenkululeko emva kongenelelo lobuKoloniyali kunye neyasemva kozuzo lwenkululeko yaseMzantsi Afrika. Iincwadi ezikhethiweyo zibhalwe phakathi kweminyaka ye-1976 ukuya kwiminyaka yama-2015. Uphando luya kujonga ukuba lungaba lukhona utshintsho kusini na kwindlela la manina ababazoba ngayo abalinganiswa ngokwezi mbali zahlukileyo kananjalo naxa bezotywa ngababhali abangamadoda. Uphando luya kutyhila kananjalo imixholo nemixholwana abayikhethayo nedlulisa iimvakalelo zabo bengamanina kumbandela wogonyamelo olukhatshwa yipatriyakhi kunye noxhatshazo abalufumana kumadoda. Xa kuphendlwa le mixholo yaba babhali bahlukileyo baneemvelaphi ezahlukileyo ngokwemontlalo bebhala ngokwamaxesha okanye iimbhali ezahlukileyo, kuya kucaca ukuba amava abo ayafana nokuba linina okanye ibhinqa. Loo mava abo anele ukuba bajikeleze kwimixholo ebizwa ngokuba yifeminist themes nakubeni izimbo zabo zokubhala zahlukile nje. Injongo kukubonisa ukuba nangona amanina aphila phantsi kweemeko neemontlalo ezahlukileyo nje, iinzima neentlungu zawo azisombulula ngendlela efanayo ngokusebenzisa usiba. Le ngxoxo ikhatshwa ziithiyori ezifana nefemayinizimu, ngakumbi ifemayinizimu yaseAfrika kunye kunye nangokoMzantsi Afrika iquka iMotherism kunye nenkcubeko ephehlelelwe phantsi kwePatriyakhi. Ezi thiyori ziludondolo lokuphendla nokuhlalutya ezi ncwadi zikhethiweyo zesiXhosa ukuze sicacelwe yeyona ndima idlalwa ngamanina kuluntu nanjengoko sisazi ukuba apha eMzantsi Afrika adlale eyona ndima yokuncedisa ekuziseni utshintsho kwimibandela yengcinezelo nasekuzuzweni kwenkululeko. Yiyo loo nto kufuneka nawo abonakale exhamla ngokulinganayo namadoda kwinkululeko ayisebenzeleyo ngokususa ugonyamelo, uxhatshazo nokubulawa kwawo ngamadoda. , Thesis (PhD) -- Humanities, School of Languages and Literatures, 2024
- Full Text:
- Date Issued: 2024-04-04
Social justice implications of the language of the court judgment genre and its development in pre- and post-independence Zimbabwe
- Authors: Nemaramba, Dylan
- Date: 2024-04-04
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/435605 , vital:73172
- Description: Access restricted. Expected release in 2026. , Thesis (PhD) -- Humanities, Linguistics and Applied Language Studies, 2024
- Full Text:
- Date Issued: 2024-04-04
- Authors: Nemaramba, Dylan
- Date: 2024-04-04
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/435605 , vital:73172
- Description: Access restricted. Expected release in 2026. , Thesis (PhD) -- Humanities, Linguistics and Applied Language Studies, 2024
- Full Text:
- Date Issued: 2024-04-04
The mediating role of generational difference on the relationship between psychological capital, psychological empowerment, organisational support and the wellbeing of South African National Defence Force members
- Authors: Selepe, Babitsanang Annah
- Date: 2024-04-04
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/435616 , vital:73173 , DOI 10.21504/10962/435616
- Description: There is a growing concern in understanding the contribution of generational difference (as a mediating variable) and factors that increase soldiers' well-being. This study aimed to determine the relationship between Psychological Capital, Psychological Empowerment and Organisational Support, and well-being. Additionally, it proposes the generational differences as a potential mediating factor among these variables. The study was guided by a positivist philosophy and quantitative research method was employed. The sample for this research consisted of 777 members from both Internal deployed within borders of Free state and those going for external deployment at De-Brug. The results show most respondents were male (78.3%) and 21.7% female. Most respondents were categorised as Gen Y (between 1981 - 1996, 67.0%), followed by Gen X (1965 - 1980, 24.8%) and Gen Z (1997 - 2012, 8.2%). Most respondents were in the SA Army, followed by SAAF and SAMHS and the SA Navy. Spearman’s Correlation and ANOVA analyses were conducted to test the relationship between the variables. The results revealed significant relationships between the variables included in the empirical model. However, Well-being does not have a statistically significant correlation with the mediation variable, generation cohort. Similarly, generation cohorts (X, Y, Z) do not significantly correlate with the predictor variables, Perceived Organisational Support, Psychological Empowerment. However, there is a statistically significant small negative correlation between generation cohort (Age) and Psychological Capital. The multiple regression analysis exhibited a significant overall model fit, indicating that 30% of the variance in employee well-being was accounted for by the predictors. Thus, this research implicates that the South African National Defence Force (SANDF) would benefit from developing a culture and adopting policies as well as programmes that prioritises psychological well-being above physical prowess. For this reason, the present study is regarded as offering a potentially valuable contribution to the existing body of research in the positive psychology and reveals practical implications and applications within the military context. The study recommends that combat readiness requires prioritising mental health above physical strength. Policymakers should consider psychological factors like psychological capital and psychological 6 empowerment. Training programmes should include Psychological Capital and cognitive resilience. There should also be further research on positive psychology and troops' well-being. These factors can help improve peacekeeping and combat force readiness. Understanding generational variations' mediating effect can inform resilience and training programmes. Military organisations should cultivate confident, capable, and educated leaders to improve military proficiency. , Thesis (PhD) -- Humanities, Psychology, 2024
- Full Text:
- Date Issued: 2024-04-04
- Authors: Selepe, Babitsanang Annah
- Date: 2024-04-04
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/435616 , vital:73173 , DOI 10.21504/10962/435616
- Description: There is a growing concern in understanding the contribution of generational difference (as a mediating variable) and factors that increase soldiers' well-being. This study aimed to determine the relationship between Psychological Capital, Psychological Empowerment and Organisational Support, and well-being. Additionally, it proposes the generational differences as a potential mediating factor among these variables. The study was guided by a positivist philosophy and quantitative research method was employed. The sample for this research consisted of 777 members from both Internal deployed within borders of Free state and those going for external deployment at De-Brug. The results show most respondents were male (78.3%) and 21.7% female. Most respondents were categorised as Gen Y (between 1981 - 1996, 67.0%), followed by Gen X (1965 - 1980, 24.8%) and Gen Z (1997 - 2012, 8.2%). Most respondents were in the SA Army, followed by SAAF and SAMHS and the SA Navy. Spearman’s Correlation and ANOVA analyses were conducted to test the relationship between the variables. The results revealed significant relationships between the variables included in the empirical model. However, Well-being does not have a statistically significant correlation with the mediation variable, generation cohort. Similarly, generation cohorts (X, Y, Z) do not significantly correlate with the predictor variables, Perceived Organisational Support, Psychological Empowerment. However, there is a statistically significant small negative correlation between generation cohort (Age) and Psychological Capital. The multiple regression analysis exhibited a significant overall model fit, indicating that 30% of the variance in employee well-being was accounted for by the predictors. Thus, this research implicates that the South African National Defence Force (SANDF) would benefit from developing a culture and adopting policies as well as programmes that prioritises psychological well-being above physical prowess. For this reason, the present study is regarded as offering a potentially valuable contribution to the existing body of research in the positive psychology and reveals practical implications and applications within the military context. The study recommends that combat readiness requires prioritising mental health above physical strength. Policymakers should consider psychological factors like psychological capital and psychological 6 empowerment. Training programmes should include Psychological Capital and cognitive resilience. There should also be further research on positive psychology and troops' well-being. These factors can help improve peacekeeping and combat force readiness. Understanding generational variations' mediating effect can inform resilience and training programmes. Military organisations should cultivate confident, capable, and educated leaders to improve military proficiency. , Thesis (PhD) -- Humanities, Psychology, 2024
- Full Text:
- Date Issued: 2024-04-04
A comparative analysis of land, labour and gender in a communal area and fast track farm in Zvimba Rural District, Zimbabwe
- Authors: Chinomona, Perpetua
- Date: 2024-04-03
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/434612 , vital:73089 , DOI 10.21504/10962/434612
- Description: This thesis provides a comparative analysis of gender, land, and labour between two different types of farming sites in rural Zimbabwe, namely long-established communal areas and the more recent Al fast track land reform resettlement areas. More specifically, the focus is on Kanzou Village and Stratford fast track resettlement farm respectively, located in Zvimba District in Mashonaland West Province. The study focuses on the period from the year 2000, the year in which the fast track resettlement programme was launched by the government. The thesis examines in particular the status and experience of women with regard to land acquisition, access and security as well as the division of labour (including assets, inputs and labour-time) in the spheres of production (i.e., agriculture) and social reproduction (i.e., the domestic sphere). This includes highlighting the power relations existing between men and women in both spheres, in the light of prevailing systems of patriarchy. Analytically, the thesis is framed in terms of feminism, drawing upon the complementary insights of Third World feminism and socialist feminism. In seeking to capture the perspectives and practices of men and women in the two sites, the fieldwork for the study entails a qualitative methodology. The findings of the research demonstrate the existence and relevance of patriarchal systems with respect to land and labour in Kanzou Village and Stratford fast track farm, with key commonalities appearing across the two sites with reference to the multiple ways in which women are disadvantaged and disempowered. Therefore, gender bias and inequality in land and labour are exhibited by the fact that men have, for instance, easier access to land, less involvement in labouring activities, control over a higher proportion of household income and a disproportionate level of power in the household. At the same time, there are certain differences between Kanzou Village and Stratford fast track farm around questions of gender, land and labour, but these are differences in degree rather than kind. Perhaps more important in explaining the differences between the two sites, and indeed differences within each site, are other variables. These variables include marital status, form or marriage (for example, customary or civil marriages), age and gender. By considering these variables as well, the thesis shows the importance of unpacking the notion of ‘woman’ to reveal the variegated and differential experiences of different categories of women in rural Zimbabwe. , Thesis (PhD) -- Faculty of Humanities, Sociology, 2023
- Full Text:
- Date Issued: 2024-04-03
- Authors: Chinomona, Perpetua
- Date: 2024-04-03
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/434612 , vital:73089 , DOI 10.21504/10962/434612
- Description: This thesis provides a comparative analysis of gender, land, and labour between two different types of farming sites in rural Zimbabwe, namely long-established communal areas and the more recent Al fast track land reform resettlement areas. More specifically, the focus is on Kanzou Village and Stratford fast track resettlement farm respectively, located in Zvimba District in Mashonaland West Province. The study focuses on the period from the year 2000, the year in which the fast track resettlement programme was launched by the government. The thesis examines in particular the status and experience of women with regard to land acquisition, access and security as well as the division of labour (including assets, inputs and labour-time) in the spheres of production (i.e., agriculture) and social reproduction (i.e., the domestic sphere). This includes highlighting the power relations existing between men and women in both spheres, in the light of prevailing systems of patriarchy. Analytically, the thesis is framed in terms of feminism, drawing upon the complementary insights of Third World feminism and socialist feminism. In seeking to capture the perspectives and practices of men and women in the two sites, the fieldwork for the study entails a qualitative methodology. The findings of the research demonstrate the existence and relevance of patriarchal systems with respect to land and labour in Kanzou Village and Stratford fast track farm, with key commonalities appearing across the two sites with reference to the multiple ways in which women are disadvantaged and disempowered. Therefore, gender bias and inequality in land and labour are exhibited by the fact that men have, for instance, easier access to land, less involvement in labouring activities, control over a higher proportion of household income and a disproportionate level of power in the household. At the same time, there are certain differences between Kanzou Village and Stratford fast track farm around questions of gender, land and labour, but these are differences in degree rather than kind. Perhaps more important in explaining the differences between the two sites, and indeed differences within each site, are other variables. These variables include marital status, form or marriage (for example, customary or civil marriages), age and gender. By considering these variables as well, the thesis shows the importance of unpacking the notion of ‘woman’ to reveal the variegated and differential experiences of different categories of women in rural Zimbabwe. , Thesis (PhD) -- Faculty of Humanities, Sociology, 2023
- Full Text:
- Date Issued: 2024-04-03
A critical analysis of the factors influencing knowledge sharing in Indian family owned businesses in South Africa
- Authors: Sha, Shafeek
- Date: 2024-04-03
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/434817 , vital:73107 , DOI 10.21504/10962/434817
- Description: It is commonly believed that family businesses have formed the backbone of many economies around the globe and that they have been the predominant form of enterprise that has given rise to some of the most famous multinational enterprises. Family businesses contribute to the wealth creation in most economies and conservative estimates suggest that 65% to 80% of all businesses worldwide are owned and managed by families. In South Africa, Indian family owned businesses contribute more to employment than any other family business. There is a general perception amongst South Africans that Indian family owned businesses are more successful and that this success is continued from one generation to the next. Intrigued by this “phenomenon” for many years, the researcher decided to investigate it. The perspective adopted for this research was to look at the research problem from a knowledge management discipline viewpoint, in general, with a specific focus on knowledge sharing and Indian family owned businesses. The purpose of this study is to critically analyse the factors that influence the effectiveness of knowledge sharing in Indian family owned businesses. So the research answered the question: How do Indian family owned businesses in South Africa share their knowledge to ensure the continued success of their businesses through succeeding generations? A positivist research paradigm and philosophy was adopted for this research together with a quantitative research approach using survey research as the research strategy of choice. After conducting an extensive literature review, the next step was to develop and formulate a theoretical model, and flowing from the model and prior research, a research instrument was developed and administered to a qualifying sample of Indian family owned businesses in South Africa. Structural equation modelling was used as the principal mode of statistical analysis to measure the relationships amongst the variables in the model proposed in this study. After analysing the empirical data, the following key factors were identified as statistically significant in being determinants of knowledge sharing in Indian family owned businesses in South Africa: organisational culture, learning organisation, and leadership. These findings serve to contribute to the existing literature within the fields of knowledge management and family business. This study will richly contribute to research-based evidence of the factors that influence knowledge sharing in Indian family owned businesses. The outcomes will allow existing and emerging family businesses to ensure the future success of their enterprises from one generation to the next by embracing the empirical findings of this research and thus ultimately contribute to the future success of the family business as a whole. , Thesis (PhD) -- Faculty of Commerce, Management, 2024
- Full Text:
- Date Issued: 2024-04-03
- Authors: Sha, Shafeek
- Date: 2024-04-03
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/434817 , vital:73107 , DOI 10.21504/10962/434817
- Description: It is commonly believed that family businesses have formed the backbone of many economies around the globe and that they have been the predominant form of enterprise that has given rise to some of the most famous multinational enterprises. Family businesses contribute to the wealth creation in most economies and conservative estimates suggest that 65% to 80% of all businesses worldwide are owned and managed by families. In South Africa, Indian family owned businesses contribute more to employment than any other family business. There is a general perception amongst South Africans that Indian family owned businesses are more successful and that this success is continued from one generation to the next. Intrigued by this “phenomenon” for many years, the researcher decided to investigate it. The perspective adopted for this research was to look at the research problem from a knowledge management discipline viewpoint, in general, with a specific focus on knowledge sharing and Indian family owned businesses. The purpose of this study is to critically analyse the factors that influence the effectiveness of knowledge sharing in Indian family owned businesses. So the research answered the question: How do Indian family owned businesses in South Africa share their knowledge to ensure the continued success of their businesses through succeeding generations? A positivist research paradigm and philosophy was adopted for this research together with a quantitative research approach using survey research as the research strategy of choice. After conducting an extensive literature review, the next step was to develop and formulate a theoretical model, and flowing from the model and prior research, a research instrument was developed and administered to a qualifying sample of Indian family owned businesses in South Africa. Structural equation modelling was used as the principal mode of statistical analysis to measure the relationships amongst the variables in the model proposed in this study. After analysing the empirical data, the following key factors were identified as statistically significant in being determinants of knowledge sharing in Indian family owned businesses in South Africa: organisational culture, learning organisation, and leadership. These findings serve to contribute to the existing literature within the fields of knowledge management and family business. This study will richly contribute to research-based evidence of the factors that influence knowledge sharing in Indian family owned businesses. The outcomes will allow existing and emerging family businesses to ensure the future success of their enterprises from one generation to the next by embracing the empirical findings of this research and thus ultimately contribute to the future success of the family business as a whole. , Thesis (PhD) -- Faculty of Commerce, Management, 2024
- Full Text:
- Date Issued: 2024-04-03
Dictionaries as pedagogic tools: a case study of selected schools in Makhanda, Eastern Cape
- Authors: Wababa, Zola Richman
- Date: 2024-04-03
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/434651 , vital:73093 , DOI 10.21504/10962/434656
- Description: The importance of dictionaries in society has been confirmed in relevant literature while their specific role in education is underlined by several studies focused on the use of dictionaries in teaching and learning. This study focuses on mother-tongue or first language (L1) isiXhosa learners and their use of dictionaries across subjects in the Intermediate Phase of primary schooling. The research sought to examine how dictionaries are used in teaching and learning and how they could be used more effectively in the teaching and learning processes, with a focus on isiXhosa L1 learners in the Makhanda area of the Sarah Baartman District of education, Eastern Cape. The general aim of this study was to improve the process and practice of using and producing Language for General Purpose (LGP) and Language for Specific Purpose (LSP) dictionaries across subjects. The study also sought to contribute to improving the functional value and user-friendliness of teaching support materials, such as dictionaries. The Curriculum and Assessment Policy Statement (CAPS) policy document states that dictionaries are essential in teaching and learning of both language and content subjects. In relation to language subjects, the CAPS is explicit about the use of dictionaries in the acquisition of vocabulary, meaning, spelling, pronunciation, and grammar, among other types of information that are integral in language attainment and learning. Nonetheless, the CAPS document does not clearly articulate the use of dictionaries in content subjects. The study draws on two branches of lexicography – namely, dictionary user research and dictionary criticism – to examine the extent to which dictionaries are problem-solving tools which assist users to meet their cognitive and communicative needs. Thus, the study seeks to influence policy and practice of the use of dictionaries as teaching and learning resource materials that could help teachers and learners better understand key concepts across subjects. A mixed-method approach was used to collect both quantitative and qualitative data using a variety of data collection instruments, viz., observation schedules, questionnaires, and interviews. The study found that although teachers were aware of dictionaries, they did not use them as a resource in teaching. Furthermore, teachers lacked skills in the use of dictionaries, therefore, they were not able to effectively integrate dictionaries in their lessons. The research also found that learners had little awareness of dictionaries and did not fully understand their role in language acquisition or content. Lastly, the study offered some insights on how dictionaries could be integrated in teaching and learning, and how their use could address some communicative and cognitive problems faced by non-mother tongue English speakers in a context where English dominates teaching and learning at the expense of learners’ L1. , Thesis (PhD) -- Faculty of Humanities, School of Languages and Literatures, 2024
- Full Text:
- Date Issued: 2024-04-03
- Authors: Wababa, Zola Richman
- Date: 2024-04-03
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/434651 , vital:73093 , DOI 10.21504/10962/434656
- Description: The importance of dictionaries in society has been confirmed in relevant literature while their specific role in education is underlined by several studies focused on the use of dictionaries in teaching and learning. This study focuses on mother-tongue or first language (L1) isiXhosa learners and their use of dictionaries across subjects in the Intermediate Phase of primary schooling. The research sought to examine how dictionaries are used in teaching and learning and how they could be used more effectively in the teaching and learning processes, with a focus on isiXhosa L1 learners in the Makhanda area of the Sarah Baartman District of education, Eastern Cape. The general aim of this study was to improve the process and practice of using and producing Language for General Purpose (LGP) and Language for Specific Purpose (LSP) dictionaries across subjects. The study also sought to contribute to improving the functional value and user-friendliness of teaching support materials, such as dictionaries. The Curriculum and Assessment Policy Statement (CAPS) policy document states that dictionaries are essential in teaching and learning of both language and content subjects. In relation to language subjects, the CAPS is explicit about the use of dictionaries in the acquisition of vocabulary, meaning, spelling, pronunciation, and grammar, among other types of information that are integral in language attainment and learning. Nonetheless, the CAPS document does not clearly articulate the use of dictionaries in content subjects. The study draws on two branches of lexicography – namely, dictionary user research and dictionary criticism – to examine the extent to which dictionaries are problem-solving tools which assist users to meet their cognitive and communicative needs. Thus, the study seeks to influence policy and practice of the use of dictionaries as teaching and learning resource materials that could help teachers and learners better understand key concepts across subjects. A mixed-method approach was used to collect both quantitative and qualitative data using a variety of data collection instruments, viz., observation schedules, questionnaires, and interviews. The study found that although teachers were aware of dictionaries, they did not use them as a resource in teaching. Furthermore, teachers lacked skills in the use of dictionaries, therefore, they were not able to effectively integrate dictionaries in their lessons. The research also found that learners had little awareness of dictionaries and did not fully understand their role in language acquisition or content. Lastly, the study offered some insights on how dictionaries could be integrated in teaching and learning, and how their use could address some communicative and cognitive problems faced by non-mother tongue English speakers in a context where English dominates teaching and learning at the expense of learners’ L1. , Thesis (PhD) -- Faculty of Humanities, School of Languages and Literatures, 2024
- Full Text:
- Date Issued: 2024-04-03
Electricity demand and supply in South Africa: is nuclear energy a feasible alternative to coal for baseload energy supply in South Africa?
- Authors: Maqanda, Vuyani
- Date: 2024-04-03
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/434802 , vital:73106 , DOI 10.21504/10962/434802
- Description: Climate change mitigation has created pressure on the energy mix choices of all countries. Highly polluting energy sources are increasingly unpopular. Renewable energy options have emerged as preferred choices for the low-emissions transition. Proponents of nuclear power have promoted the technology as a low-emissions technology by focusing on the operational phase and ignoring the other polluting phases. South Africa generated about 83% of its electricity supply from coal in 2019 and was rated as the 12th most polluting country in the world. In addition to the high pollution levels, the ageing coal fleet suffered from poor maintenance that resulted in frequent power blackouts. One of the government’s energy plans from 2010 proposed the addition of 9 600 MW of nuclear capacity by 2030. However, this plan was not implemented. This study investigates why nuclear power historically never expanded beyond a single power facility in South Africa as well as the possible future role of nuclear power in alleviating South Africa’s current electricity supply constraints and emissions commitments in the period up to 2050. Qualitative analysis is used for this study with a focus on historical document analysis and interviews with energy experts. Two research methods, case studies, and expert opinions were used in this study with data sourced from policy documents, Statistics South Africa, the World Bank, and published articles from various platforms. The Hotelling model, focusing on the impact of price differentials on energy transitions, was used as a theoretical framework. The conclusion from applying the model was that nuclear power was more expensive than the other options even when internalisation of pollution externalities was considered and therefore nuclear power could not displace the cheaper alternatives like coal based on price factors alone. The Multi-Level Perspective, working through institutions, revealed that the institutional setting did not support a transition to nuclear energy. The lack of coordination of strategies derailed the transition. The comparative case study analysis of Germany, the UK, Australia, and India reaffirmed this as countries with better coordination succeeded in transitions. Energy experts offered differing views on the feasibility of nuclear power but many agreed that South Africa should focus on technologies it has better competencies in. , Thesis (PhD) -- Faculty of Commerce, Economics and Economic History, 2024
- Full Text:
- Date Issued: 2024-04-03
- Authors: Maqanda, Vuyani
- Date: 2024-04-03
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/434802 , vital:73106 , DOI 10.21504/10962/434802
- Description: Climate change mitigation has created pressure on the energy mix choices of all countries. Highly polluting energy sources are increasingly unpopular. Renewable energy options have emerged as preferred choices for the low-emissions transition. Proponents of nuclear power have promoted the technology as a low-emissions technology by focusing on the operational phase and ignoring the other polluting phases. South Africa generated about 83% of its electricity supply from coal in 2019 and was rated as the 12th most polluting country in the world. In addition to the high pollution levels, the ageing coal fleet suffered from poor maintenance that resulted in frequent power blackouts. One of the government’s energy plans from 2010 proposed the addition of 9 600 MW of nuclear capacity by 2030. However, this plan was not implemented. This study investigates why nuclear power historically never expanded beyond a single power facility in South Africa as well as the possible future role of nuclear power in alleviating South Africa’s current electricity supply constraints and emissions commitments in the period up to 2050. Qualitative analysis is used for this study with a focus on historical document analysis and interviews with energy experts. Two research methods, case studies, and expert opinions were used in this study with data sourced from policy documents, Statistics South Africa, the World Bank, and published articles from various platforms. The Hotelling model, focusing on the impact of price differentials on energy transitions, was used as a theoretical framework. The conclusion from applying the model was that nuclear power was more expensive than the other options even when internalisation of pollution externalities was considered and therefore nuclear power could not displace the cheaper alternatives like coal based on price factors alone. The Multi-Level Perspective, working through institutions, revealed that the institutional setting did not support a transition to nuclear energy. The lack of coordination of strategies derailed the transition. The comparative case study analysis of Germany, the UK, Australia, and India reaffirmed this as countries with better coordination succeeded in transitions. Energy experts offered differing views on the feasibility of nuclear power but many agreed that South Africa should focus on technologies it has better competencies in. , Thesis (PhD) -- Faculty of Commerce, Economics and Economic History, 2024
- Full Text:
- Date Issued: 2024-04-03
Issues in language acquisition planning in Zimbabwe: the case of Ndebele within the primary education system
- Authors: Masuku, Seabird
- Date: 2024-04-03
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/434626 , vital:73091 , DOI 10.21504/10962/434627
- Description: This thesis discusses pertinent language issues within the primary school system in Zimbabwe in view of complaints (over many years) of communities in the two Matabeleland provinces and Bulawayo about high failure rates of learners in the final grade 7 examinations. It also interrogates the government’s commitment to the development of indigenous languages in the primary school system, particularly in the three provinces mentioned above as mirrored in the 2013 constitution of the country. The study conducted traces the language trends exhibited currently back to their beginnings during the colonial era in language planning by the government and the policies that informed such planning. What obtains on the ground seems to be violating the principles behind the declaration of the International Mother Language Day (30C/62) proclaimed by the General Conference of the United Nations Educational, Scientific and Cultural Organization (UNESCO) in November 1999. On 16 May 2007 the United Nations General Assembly, in its resolution A/RES/61/266, called upon Member States (Zimbabwe included) "to promote the preservation and protection of all languages used by peoples of the world". The amended education act of 2006 states that in Zimbabwe’s primary schools early learning must be done through mother tongue instruction then switch to English in grade 4 upwards. As a first step of a child’s academic life, the lower primary education needs to be conducted in the child’s mother tongue to bridge the gap between the child’s home environment and the new school environment as well as to reduce culture shock associated with the sudden introduction of a new language. Studies, such as those done by Noormohamadi, (2008) and Mackenzie, (2013) have shown that children tend to understand better if they are taught in their mother tongue. In this thesis I seek to establish if the teaching of Ndebele at primary school reveals the socio-cultural ideology (awareness of circumstances surrounding individuals and how their behaviours are affected, specifically by their surroundings, social and cultural factors) and political ideology (thinking structures about the way policies should be run) underpinning language planning in Zimbabwe. It is my observation and argument that the Education Act proclaims what has not been practised on the ground through teacher training and deployment practices. To establish if the teaching of Ndebele at primary school reveals the socio-cultural and political ideologies underpinning language planning in Zimbabwe, I carried out research in Matabeleland South, Bulawayo and Matabeleland North provinces covering a total of 27 schools, 27 heads of school and 135 teachers. The research’s main aims were to find out if Ndebele was taught at school, by who and using what materials. It should be noted that mother tongue, in learning, acts as a basis of interpretation of subsequent concepts. When a child is learning new concepts or words in the second language, he or she first searches the equivalent in his or her mother tongue. If the primary language has not been developed well enough to have such equivalents, such a child is likely to have problems in forming new concepts in the second language. The role of language in meaning, therefore, is a variable that depends on the socio-geographical location of the languages and their speakers. The research established that, indigenous languages, Ndebele included, are not developed by the government through financial support for teaching material production and qualified teacher deployment. Instead, it was discovered that in Matabeleland there are some learners at primary school who are taught by a Shona-speaking teacher who cannot communicate properly with the learners. It should be remembered that a primary language is used by a child as the foundation to learn the basic concepts in his or her own language and to give him or her freedom to express himself or herself without the inhibitions imposed by an insufficient mastery of the medium of instruction. As a way of concluding the research I found it necessary that the use of mother tongue by learners at lower grades of primary school be strengthened through the deployment of teachers who can teach Ndebele properly because it provides a strong foundation for further education. Using the mother tongue, students learn to think, communicate and acquire an intuitive understanding of grammar. The mother tongue is; therefore, the greatest asset and vital tool people use to acquire new concepts. , Thesis (PhD) -- Faculty of Humanities, School of Languages and Literatures, 2024
- Full Text:
- Date Issued: 2024-04-03
- Authors: Masuku, Seabird
- Date: 2024-04-03
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/434626 , vital:73091 , DOI 10.21504/10962/434627
- Description: This thesis discusses pertinent language issues within the primary school system in Zimbabwe in view of complaints (over many years) of communities in the two Matabeleland provinces and Bulawayo about high failure rates of learners in the final grade 7 examinations. It also interrogates the government’s commitment to the development of indigenous languages in the primary school system, particularly in the three provinces mentioned above as mirrored in the 2013 constitution of the country. The study conducted traces the language trends exhibited currently back to their beginnings during the colonial era in language planning by the government and the policies that informed such planning. What obtains on the ground seems to be violating the principles behind the declaration of the International Mother Language Day (30C/62) proclaimed by the General Conference of the United Nations Educational, Scientific and Cultural Organization (UNESCO) in November 1999. On 16 May 2007 the United Nations General Assembly, in its resolution A/RES/61/266, called upon Member States (Zimbabwe included) "to promote the preservation and protection of all languages used by peoples of the world". The amended education act of 2006 states that in Zimbabwe’s primary schools early learning must be done through mother tongue instruction then switch to English in grade 4 upwards. As a first step of a child’s academic life, the lower primary education needs to be conducted in the child’s mother tongue to bridge the gap between the child’s home environment and the new school environment as well as to reduce culture shock associated with the sudden introduction of a new language. Studies, such as those done by Noormohamadi, (2008) and Mackenzie, (2013) have shown that children tend to understand better if they are taught in their mother tongue. In this thesis I seek to establish if the teaching of Ndebele at primary school reveals the socio-cultural ideology (awareness of circumstances surrounding individuals and how their behaviours are affected, specifically by their surroundings, social and cultural factors) and political ideology (thinking structures about the way policies should be run) underpinning language planning in Zimbabwe. It is my observation and argument that the Education Act proclaims what has not been practised on the ground through teacher training and deployment practices. To establish if the teaching of Ndebele at primary school reveals the socio-cultural and political ideologies underpinning language planning in Zimbabwe, I carried out research in Matabeleland South, Bulawayo and Matabeleland North provinces covering a total of 27 schools, 27 heads of school and 135 teachers. The research’s main aims were to find out if Ndebele was taught at school, by who and using what materials. It should be noted that mother tongue, in learning, acts as a basis of interpretation of subsequent concepts. When a child is learning new concepts or words in the second language, he or she first searches the equivalent in his or her mother tongue. If the primary language has not been developed well enough to have such equivalents, such a child is likely to have problems in forming new concepts in the second language. The role of language in meaning, therefore, is a variable that depends on the socio-geographical location of the languages and their speakers. The research established that, indigenous languages, Ndebele included, are not developed by the government through financial support for teaching material production and qualified teacher deployment. Instead, it was discovered that in Matabeleland there are some learners at primary school who are taught by a Shona-speaking teacher who cannot communicate properly with the learners. It should be remembered that a primary language is used by a child as the foundation to learn the basic concepts in his or her own language and to give him or her freedom to express himself or herself without the inhibitions imposed by an insufficient mastery of the medium of instruction. As a way of concluding the research I found it necessary that the use of mother tongue by learners at lower grades of primary school be strengthened through the deployment of teachers who can teach Ndebele properly because it provides a strong foundation for further education. Using the mother tongue, students learn to think, communicate and acquire an intuitive understanding of grammar. The mother tongue is; therefore, the greatest asset and vital tool people use to acquire new concepts. , Thesis (PhD) -- Faculty of Humanities, School of Languages and Literatures, 2024
- Full Text:
- Date Issued: 2024-04-03
The influence of electronic-consumer experience (e-CX) on consumer post-purchase outcomes of South African e-commerce retail organisations
- Authors: Williams, Alyssa Shawntay
- Date: 2024-04-03
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/434828 , vital:73108
- Description: Access restricted. Expected release in 2026. , Thesis (PhD) -- Faculty of Commerce, Management, 2024
- Full Text:
- Date Issued: 2024-04-03
- Authors: Williams, Alyssa Shawntay
- Date: 2024-04-03
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/434828 , vital:73108
- Description: Access restricted. Expected release in 2026. , Thesis (PhD) -- Faculty of Commerce, Management, 2024
- Full Text:
- Date Issued: 2024-04-03
The Zimbabwe National Gender Policy (NGP) 2013–2017 and Women’s Economic Empowerment (WEE): a study of small-scale gold miners in the Bubi and Gwanda rural districts, Zimbabwe
- Moyo, Phoebe Michelle Zibusiso Sandi
- Authors: Moyo, Phoebe Michelle Zibusiso Sandi
- Date: 2024-04-03
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/434638 , vital:73092 , DOI 10.21504/10962/434638
- Description: The study examines the impact of Zimbabwe’s second National Gender Policy (NGP) 2013-2017 under the Ministry of Women’s Affairs, Gender and Community Development on women’s access to and control over productive resources in the artisanal and small-scale gold mining sector in Bubi and Gwanda rural districts of Zimbabwe. Despite the implementation of the NGP over the past fourteen years, its effect on the economic empowerment of women has not been investigated adequately. Women’s economic empowerment (WEE) is recognized as a crucial development strategy. However, it faces challenges related to the tensions between structure and agency. Some perceive WEE as an entrepreneurial concept focusing on equal access and control over productive resources like credit, equipment, skills, and business training. Others argue that WEE should encompass more than just resource access and control by addressing structural factors that hinder women’s agency e.g. unequal social relations between men and women, patriarchy, unpaid care work, and sociocultural norms. The study employed a hybrid lens, combining structure and agency to analyse the implementation of the NGP’s empowerment programs. Drawing on Kabeer’s (1994) Social Relations Approach (SRA), the study utilized two key concepts from the SRA, namely social relations and institutional analysis, to examine the interaction between the NGP and various institutions (market, community, and family) where women are located. To gain a comprehensive understanding of the ways in which the NGP has supported or impeded WEE among the female small-scale gold miners in Bubi and Gwanda, a qualitative approach was employed as an investigative method. The findings indicated that the NGP adopts a liberal or agency centred approach to WEE. This approach emphasizes women’s agency and their ability to fulfil their potential in the public sphere. The NGP has facilitated access to credit, equipment, skills, and business training. However, the evidence also highlighted the uneven implementation of the NGP’s empowerment programs between the Bubi and Gwanda districts. Overall, the evidence revealed that, while the NGP has addressed gender inequalities to a limited degree, it has also reinforced class inequalities. The NGP’s empowerment programs have overlooked the structural factors that keep women in subordinate positions, such as the unequal social relations that exist between men and women, patriarchy, unpaid care work and sociocultural norms. , Thesis (PhD) -- Faculty of Humanities, Sociology, 2024
- Full Text:
- Date Issued: 2024-04-03
- Authors: Moyo, Phoebe Michelle Zibusiso Sandi
- Date: 2024-04-03
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/434638 , vital:73092 , DOI 10.21504/10962/434638
- Description: The study examines the impact of Zimbabwe’s second National Gender Policy (NGP) 2013-2017 under the Ministry of Women’s Affairs, Gender and Community Development on women’s access to and control over productive resources in the artisanal and small-scale gold mining sector in Bubi and Gwanda rural districts of Zimbabwe. Despite the implementation of the NGP over the past fourteen years, its effect on the economic empowerment of women has not been investigated adequately. Women’s economic empowerment (WEE) is recognized as a crucial development strategy. However, it faces challenges related to the tensions between structure and agency. Some perceive WEE as an entrepreneurial concept focusing on equal access and control over productive resources like credit, equipment, skills, and business training. Others argue that WEE should encompass more than just resource access and control by addressing structural factors that hinder women’s agency e.g. unequal social relations between men and women, patriarchy, unpaid care work, and sociocultural norms. The study employed a hybrid lens, combining structure and agency to analyse the implementation of the NGP’s empowerment programs. Drawing on Kabeer’s (1994) Social Relations Approach (SRA), the study utilized two key concepts from the SRA, namely social relations and institutional analysis, to examine the interaction between the NGP and various institutions (market, community, and family) where women are located. To gain a comprehensive understanding of the ways in which the NGP has supported or impeded WEE among the female small-scale gold miners in Bubi and Gwanda, a qualitative approach was employed as an investigative method. The findings indicated that the NGP adopts a liberal or agency centred approach to WEE. This approach emphasizes women’s agency and their ability to fulfil their potential in the public sphere. The NGP has facilitated access to credit, equipment, skills, and business training. However, the evidence also highlighted the uneven implementation of the NGP’s empowerment programs between the Bubi and Gwanda districts. Overall, the evidence revealed that, while the NGP has addressed gender inequalities to a limited degree, it has also reinforced class inequalities. The NGP’s empowerment programs have overlooked the structural factors that keep women in subordinate positions, such as the unequal social relations that exist between men and women, patriarchy, unpaid care work and sociocultural norms. , Thesis (PhD) -- Faculty of Humanities, Sociology, 2024
- Full Text:
- Date Issued: 2024-04-03
Systematic effects and mitigation strategies in observations of cosmic re-ionisation with the Hydrogen Epoch of Reionization Array
- Authors: Charles, Ntsikelelo
- Date: 2024
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/432605 , vital:72886 , DOI 10.21504/10962/432605
- Description: The 21 cm transition from neutral Hydrogen promises to be the best observational probe of the Epoch of Reionisation (EoR). It has driven the construction of the new generation of lowfrequency radio interferometric arrays, including the Hydrogen Epoch of Reionization Array (HERA). The main difficulty in measuring the 21 cm signal is the presence of bright foregrounds that require very accurate interferometric calibration. However, the non-smooth instrumental response of the antenna as a result of mutual coupling complicates the calibration process by introducing non-smooth calibration errors. Additionally, incomplete sky models are typically used in calibration due to the limited depth and resolution of current source catalogues. Combined with the instrumental response, the use of incomplete sky models during calibration can result in non-smooth calibration errors. These, overall, impart spectral structure on smooth foregrounds, leading to foreground power leakage into the EoR window. In this thesis we explored the use of fringe rate filters (Parsons et al., 2016) as a mean to mitigate calibration errors resulting from the effects of mutual coupling and the use of an incomplete sky model during calibration. We found that the use of a simple notch filter mitigates calibration errors reducing the foreground power leakage into the EoR window by a factor of ∼ 102. Thyagarajan et al. (2018) proposed the use of closure phase quantities as a means to detect the 21 cm signal, which has the advantage of being independent (to first order) from calibration errors and, therefore, bypasses the need for accurate calibration. In this thesis, we explore the impact of primary beam patterns affected by mutual coupling on the closure phase. We found that primary beams affected by mutual coupling lead to a leakage of foreground power into the EoR window, which can be up to ∼ 104 times and is mainly caused by the unsmooth spectral structure primary of primary beam sidelobes affected by mutual coupling. This power leakage was confined to k < 0.3 pseudo h Mpc−1. Lastly, we also proposed and demonstrated an analysis technique that can be used to derive a flux scale correction in post-calibrated HERA data. We found that after applying flux scale correction to calibrated HERA data, the bandpass error reduces significantly, with an improvement of 6%. The derived flux scale correction was antenna-independent, and it can be applied to fix the overall visibility spectrum scale of H4C data post-calibration in a fashion similar to Jacobs et al. (2013). , Thesis (PhD) -- Faculty of Science, Physics and Electronics, 2024
- Full Text:
- Date Issued: 2024
- Authors: Charles, Ntsikelelo
- Date: 2024
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/432605 , vital:72886 , DOI 10.21504/10962/432605
- Description: The 21 cm transition from neutral Hydrogen promises to be the best observational probe of the Epoch of Reionisation (EoR). It has driven the construction of the new generation of lowfrequency radio interferometric arrays, including the Hydrogen Epoch of Reionization Array (HERA). The main difficulty in measuring the 21 cm signal is the presence of bright foregrounds that require very accurate interferometric calibration. However, the non-smooth instrumental response of the antenna as a result of mutual coupling complicates the calibration process by introducing non-smooth calibration errors. Additionally, incomplete sky models are typically used in calibration due to the limited depth and resolution of current source catalogues. Combined with the instrumental response, the use of incomplete sky models during calibration can result in non-smooth calibration errors. These, overall, impart spectral structure on smooth foregrounds, leading to foreground power leakage into the EoR window. In this thesis we explored the use of fringe rate filters (Parsons et al., 2016) as a mean to mitigate calibration errors resulting from the effects of mutual coupling and the use of an incomplete sky model during calibration. We found that the use of a simple notch filter mitigates calibration errors reducing the foreground power leakage into the EoR window by a factor of ∼ 102. Thyagarajan et al. (2018) proposed the use of closure phase quantities as a means to detect the 21 cm signal, which has the advantage of being independent (to first order) from calibration errors and, therefore, bypasses the need for accurate calibration. In this thesis, we explore the impact of primary beam patterns affected by mutual coupling on the closure phase. We found that primary beams affected by mutual coupling lead to a leakage of foreground power into the EoR window, which can be up to ∼ 104 times and is mainly caused by the unsmooth spectral structure primary of primary beam sidelobes affected by mutual coupling. This power leakage was confined to k < 0.3 pseudo h Mpc−1. Lastly, we also proposed and demonstrated an analysis technique that can be used to derive a flux scale correction in post-calibrated HERA data. We found that after applying flux scale correction to calibrated HERA data, the bandpass error reduces significantly, with an improvement of 6%. The derived flux scale correction was antenna-independent, and it can be applied to fix the overall visibility spectrum scale of H4C data post-calibration in a fashion similar to Jacobs et al. (2013). , Thesis (PhD) -- Faculty of Science, Physics and Electronics, 2024
- Full Text:
- Date Issued: 2024
Rationalisation of magisterial districts to transform the judiciary and widen access to justice under the RSA constitution of 1996
- Authors: Skosana, Jacob
- Date: 2024-01
- Subjects: Justice, Administration of , Law and socialism , Human rights -- South Africa
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/28162 , vital:72777
- Description: The study examines how pre-1994 magisterial districts jurisdictions denied access to justice to many South Africans, and ongoing efforts to reverse this injustice. Delayed rationalisation of the judiciary and reform of the courts territorial jurisdiction during the apartheid era exacerbated the problem. The courts administered justice along spatial racial divide, and given the location of the courts, many black communities had to commute long distances to access justice and at a great cost and inconvenience. The Constitution of South Africa of 1996 provides not only for the right to equality before the law and equal protection and benefit of the law but also the right to access the courts and seek recourse. In a period spanning eight years from December 2014, new magisterial districts were proclaimed in all the nine provinces of South Africa. Despite this milestone and the imperative of the 1996 Constitution, the rationalisation process is still in its infancy: old legislation and judicial structures remain intact; divisions of the High Court continue to exercise jurisdictions determined for the pre-1994 constitutional dispensation. The status quo continues to perpetuate the denial of access to justice to communities especially those living in areas that hitherto formed part of the former homelands and self-governing ‘states’. The study was conducted through a desktop survey of primary and secondary material relevant to the rationalisation process. It drew lessons from the re-demarcation of municipal boundaries which, like magisterial districts, were based on racial laws and policies of the past. It also contrasted rationalisation principles in comparable jurisdictions. The findings provide a useful contribution to the ongoing effort to effect rationalisation of the court system. They also contribute to knowledge and enriches our understanding of the relationship that underpins the administration of justice in a dispensation driven by democratic, human rights and constitutional ethos. , Thesis (PhD (LLD)) -- Faculty of Law, 2024
- Full Text:
- Date Issued: 2024-01
- Authors: Skosana, Jacob
- Date: 2024-01
- Subjects: Justice, Administration of , Law and socialism , Human rights -- South Africa
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/28162 , vital:72777
- Description: The study examines how pre-1994 magisterial districts jurisdictions denied access to justice to many South Africans, and ongoing efforts to reverse this injustice. Delayed rationalisation of the judiciary and reform of the courts territorial jurisdiction during the apartheid era exacerbated the problem. The courts administered justice along spatial racial divide, and given the location of the courts, many black communities had to commute long distances to access justice and at a great cost and inconvenience. The Constitution of South Africa of 1996 provides not only for the right to equality before the law and equal protection and benefit of the law but also the right to access the courts and seek recourse. In a period spanning eight years from December 2014, new magisterial districts were proclaimed in all the nine provinces of South Africa. Despite this milestone and the imperative of the 1996 Constitution, the rationalisation process is still in its infancy: old legislation and judicial structures remain intact; divisions of the High Court continue to exercise jurisdictions determined for the pre-1994 constitutional dispensation. The status quo continues to perpetuate the denial of access to justice to communities especially those living in areas that hitherto formed part of the former homelands and self-governing ‘states’. The study was conducted through a desktop survey of primary and secondary material relevant to the rationalisation process. It drew lessons from the re-demarcation of municipal boundaries which, like magisterial districts, were based on racial laws and policies of the past. It also contrasted rationalisation principles in comparable jurisdictions. The findings provide a useful contribution to the ongoing effort to effect rationalisation of the court system. They also contribute to knowledge and enriches our understanding of the relationship that underpins the administration of justice in a dispensation driven by democratic, human rights and constitutional ethos. , Thesis (PhD (LLD)) -- Faculty of Law, 2024
- Full Text:
- Date Issued: 2024-01
An exploration of stakeholder perceptions of the quality of teaching and learning in higher education
- Authors: Jackson,Linda Grace
- Date: 2023-12
- Subjects: Quality assurance --Education (Higher)-- South Africa , Teaching and learning – Nelson Mandela University , Quality education—South Africa
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/62464 , vital:72757
- Description: Quality in higher education is a complex and evolving concept that has been a subject of measurement, assurance and promotion in universities globally for the past three decades. However, its precise definition remains elusive due to its fluid nature, influenced by various contextual factors and stakeholder perspectives. This study explored the concepts of quality teaching and quality learning within the specific context of Nelson Mandela University, focusing on two critical internal stakeholder groups, lecturers and students. By maintaining a constant context, the study sought to gain a deeper understanding of how these stakeholders perceived and contributed to the overall quality of education at the institution. Defining quality in higher education (HE) is important, as it directly impacts on the evaluation processes within educational institutions. Presently, most Higher Education Institutions (HEIs) assess quality using tangible inputs and outputs, resulting in a quantifiable representation of quality. Despite this approach, realistically, the anticipated improvements in the quality of teaching and learning are not apparent, leading to concerns about graduate readiness for the demands of the workforce. This situation raises imperative questions about the quality of teaching and learning within HEIs, necessitating a response to address this issue. This study used the conceptual model Schindler et al. (2015) developed to investigate stakeholder perceptions of quality teaching and quality learning in higher education (HE). The research followed a novel perspective by uncoupling quality in HE from the prevailing neoliberal approach and considering quality in HE within social inclusion interventions (Gidley et al., 2010a) already in place in HE settings. The research methodology expanded on social inclusion theory and employed a qualitative, participative and visual approach adapted from Mmogo-method®, an indigenous method. The research design fostered active participation from the participants, who assumed the role of co-researchers. Participants constructed their answers to the research question using unstructured materials, subsequently sharing, explaining, and interpreting their viewpoints within the group setting. , Thesis (PhD) -- Faculty of Education, School of teaching and learning, 2023
- Full Text:
- Date Issued: 2023-12
- Authors: Jackson,Linda Grace
- Date: 2023-12
- Subjects: Quality assurance --Education (Higher)-- South Africa , Teaching and learning – Nelson Mandela University , Quality education—South Africa
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/62464 , vital:72757
- Description: Quality in higher education is a complex and evolving concept that has been a subject of measurement, assurance and promotion in universities globally for the past three decades. However, its precise definition remains elusive due to its fluid nature, influenced by various contextual factors and stakeholder perspectives. This study explored the concepts of quality teaching and quality learning within the specific context of Nelson Mandela University, focusing on two critical internal stakeholder groups, lecturers and students. By maintaining a constant context, the study sought to gain a deeper understanding of how these stakeholders perceived and contributed to the overall quality of education at the institution. Defining quality in higher education (HE) is important, as it directly impacts on the evaluation processes within educational institutions. Presently, most Higher Education Institutions (HEIs) assess quality using tangible inputs and outputs, resulting in a quantifiable representation of quality. Despite this approach, realistically, the anticipated improvements in the quality of teaching and learning are not apparent, leading to concerns about graduate readiness for the demands of the workforce. This situation raises imperative questions about the quality of teaching and learning within HEIs, necessitating a response to address this issue. This study used the conceptual model Schindler et al. (2015) developed to investigate stakeholder perceptions of quality teaching and quality learning in higher education (HE). The research followed a novel perspective by uncoupling quality in HE from the prevailing neoliberal approach and considering quality in HE within social inclusion interventions (Gidley et al., 2010a) already in place in HE settings. The research methodology expanded on social inclusion theory and employed a qualitative, participative and visual approach adapted from Mmogo-method®, an indigenous method. The research design fostered active participation from the participants, who assumed the role of co-researchers. Participants constructed their answers to the research question using unstructured materials, subsequently sharing, explaining, and interpreting their viewpoints within the group setting. , Thesis (PhD) -- Faculty of Education, School of teaching and learning, 2023
- Full Text:
- Date Issued: 2023-12
Assessing the effects of fish stock management on Cape gannet foraging behaviour in South Africa
- Strydom, Zanri, Grémillet, David, Pichegru, Lorien
- Authors: Strydom, Zanri , Grémillet, David , Pichegru, Lorien
- Date: 2023-12
- Subjects: Gannets -- South Africa , Birds of prey -- Behavior -- South Africa , Fish stock assessment
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/62622 , vital:72887
- Description: Seabirds are one of the most threatened groups of birds under both marine and terrestrial pressures. Among seabirds, the Cape gannet Morus capensis is a southern African endemic species facing several pressures of anthropogenic origin, including competition with industrial fisheries on small pelagic fish stocks. Cape gannets, being a long-lived species that is sensitive to environmental changes, are sentinels of change in oceanic environments granting it important to understand which factors influence their foraging behaviour and breeding outputs. For example, factors like age can result in a loss of physical capabilities which can lead to behavioral compensation and subsequent changes in chick provisioning rates and amounts. With the current fisheries management the fish stocks are continually decreasing, indicating the importance of an updated fine-scale assessment on the spatiotemporal overlap between foraging gannets and fisheries. The first objective of this thesis was to determine the influence of adult Cape gannets’ age and sex on their foraging characteristics and energy expenditure during foraging. I equipped chick-rearing Cape gannets of known age and sex with a 3D accelerometer and GPS device. Foraging effort (trip duration, foraging path and maximum distance to the nest) did not differ between sexes nor with age in Cape gannets. Both sexes rested less on the water with age. Aging females also spent more time in flight than males. The age- and sexual differences in energy expenditure prevalent in our study might reflect niche and/or risk partitioning strategies to ensure adequate provisioning to the chick. The second objective of this thesis was to determine the influence of fisheries catch rates, sardine and anchovy biomass, and adult foraging effort on chick growth rates in Cape gannets, using a long-term dataset collected between 2005 and 2020 on Malgas Island. I equipped chick-rearing adults with a GPS device and I weighed the chicks for between 3 to 6 increments to calculate the average daily mass increment. Of all the variables, foraging trip duration was the main determinant of daily growth rates, with chicks benefitting from parents’ shorter foraging trip durations. Chicks tended to grow slower when fisheries catch of sardine and anchovy were higher, possibly an effect of competition with fisheries. Chicks also grew faster when fish biomass was higher. This long-term monitoring demonstrated the possible effect of food competition between Cape gannets and fisheries, with negative impacts on gannet fitness as determined via chick growth rates. The third objective of this thesis was to determine the influence of both the biomass and fisheries catch rates of sardine and anchovy on Cape gannet foraging effort at a spatial and temporal scale. This was achieved by equipping a total of 668 chick-rearing Cape gannets with a GPS device. With an increase in fisheries catch there was an increase in the birds’ foraging effort. To reduce competition between the gannets and fisheries, the gannets’ core foraging areas seldomly overlapped with the fisheries catch locations, at the cost of the gannets’ increased foraging effort. One method to halt the Cape gannet population decline would be to conserve the fish resources close to the breeding colonies. This would reduce the birds’ foraging whereby increasing their fitness. Safeguarding small pelagic fish to ensure the perseverance of the remaining Benguela seabird populations, would lead to preserving the Benguela marine ecosystem as a whole. My study provided new insight into effects of fish stock management on Cape gannet foraging behaviour in South Africa, and the need for adequate management to ensure population persistence. , Thesis (PhD) -- Faculty of Science, School of Environmental Sciences, 2023
- Full Text:
- Date Issued: 2023-12
- Authors: Strydom, Zanri , Grémillet, David , Pichegru, Lorien
- Date: 2023-12
- Subjects: Gannets -- South Africa , Birds of prey -- Behavior -- South Africa , Fish stock assessment
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/62622 , vital:72887
- Description: Seabirds are one of the most threatened groups of birds under both marine and terrestrial pressures. Among seabirds, the Cape gannet Morus capensis is a southern African endemic species facing several pressures of anthropogenic origin, including competition with industrial fisheries on small pelagic fish stocks. Cape gannets, being a long-lived species that is sensitive to environmental changes, are sentinels of change in oceanic environments granting it important to understand which factors influence their foraging behaviour and breeding outputs. For example, factors like age can result in a loss of physical capabilities which can lead to behavioral compensation and subsequent changes in chick provisioning rates and amounts. With the current fisheries management the fish stocks are continually decreasing, indicating the importance of an updated fine-scale assessment on the spatiotemporal overlap between foraging gannets and fisheries. The first objective of this thesis was to determine the influence of adult Cape gannets’ age and sex on their foraging characteristics and energy expenditure during foraging. I equipped chick-rearing Cape gannets of known age and sex with a 3D accelerometer and GPS device. Foraging effort (trip duration, foraging path and maximum distance to the nest) did not differ between sexes nor with age in Cape gannets. Both sexes rested less on the water with age. Aging females also spent more time in flight than males. The age- and sexual differences in energy expenditure prevalent in our study might reflect niche and/or risk partitioning strategies to ensure adequate provisioning to the chick. The second objective of this thesis was to determine the influence of fisheries catch rates, sardine and anchovy biomass, and adult foraging effort on chick growth rates in Cape gannets, using a long-term dataset collected between 2005 and 2020 on Malgas Island. I equipped chick-rearing adults with a GPS device and I weighed the chicks for between 3 to 6 increments to calculate the average daily mass increment. Of all the variables, foraging trip duration was the main determinant of daily growth rates, with chicks benefitting from parents’ shorter foraging trip durations. Chicks tended to grow slower when fisheries catch of sardine and anchovy were higher, possibly an effect of competition with fisheries. Chicks also grew faster when fish biomass was higher. This long-term monitoring demonstrated the possible effect of food competition between Cape gannets and fisheries, with negative impacts on gannet fitness as determined via chick growth rates. The third objective of this thesis was to determine the influence of both the biomass and fisheries catch rates of sardine and anchovy on Cape gannet foraging effort at a spatial and temporal scale. This was achieved by equipping a total of 668 chick-rearing Cape gannets with a GPS device. With an increase in fisheries catch there was an increase in the birds’ foraging effort. To reduce competition between the gannets and fisheries, the gannets’ core foraging areas seldomly overlapped with the fisheries catch locations, at the cost of the gannets’ increased foraging effort. One method to halt the Cape gannet population decline would be to conserve the fish resources close to the breeding colonies. This would reduce the birds’ foraging whereby increasing their fitness. Safeguarding small pelagic fish to ensure the perseverance of the remaining Benguela seabird populations, would lead to preserving the Benguela marine ecosystem as a whole. My study provided new insight into effects of fish stock management on Cape gannet foraging behaviour in South Africa, and the need for adequate management to ensure population persistence. , Thesis (PhD) -- Faculty of Science, School of Environmental Sciences, 2023
- Full Text:
- Date Issued: 2023-12
Evaluation of the antidiabetic potential, safety and efficacy of selected natural products using zebrafish larvae and in vitro bioassays
- Reddy, Shanika, Dambuza, Ntokozo
- Authors: Reddy, Shanika , Dambuza, Ntokozo
- Date: 2023-12
- Subjects: Traditional medicine -- Research -- South Africa , Medicinal plants -- South Africa -- Research , Insulin resistance
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/62575 , vital:72825
- Description: Abstract. , Thesis (MSc) -- Faculty of Science, School of Biomolecular & Chemical Sciences, 2023
- Full Text:
- Date Issued: 2023-12
- Authors: Reddy, Shanika , Dambuza, Ntokozo
- Date: 2023-12
- Subjects: Traditional medicine -- Research -- South Africa , Medicinal plants -- South Africa -- Research , Insulin resistance
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/62575 , vital:72825
- Description: Abstract. , Thesis (MSc) -- Faculty of Science, School of Biomolecular & Chemical Sciences, 2023
- Full Text:
- Date Issued: 2023-12