Governing pregnancy in South Africa: political and health debate, policy and procedures
- Authors: Du Plessis, Ulandi
- Date: 2019
- Subjects: South Africa. Department of Health (1994- ) , Maternal health services -- South Africa , Mothers -- Mortality -- South Africa , Prenatal care -- South Africa , African mothers -- Mortality -- South Africa
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/76552 , vital:30600
- Description: South Africa democratised in 1994. However, due to the discriminatory and segregationist character of the preceding regime, vast swathes of the country’s spaces and people entered the democratic period heavily deprived of essential government services. This was the case with health care in general, including maternal health care. There were also little to no national data available on maternal deaths, especially among the black population. One of the first tasks of the new National Department of Health (NDoH) was to target the high maternal mortality rate. The NDoH made maternal deaths notifiable by law and instituted auditing and information gathering systems in the health sector; health infrastructure was expanded exponentially, and maternal health care was made free. Despite this, the last 24 years have seen the maternal mortality escalate. The latest statistics show that between 1200 and 1300 women die in the South African public health sector each year during pregnancy and the puerperium. This puts the current institutional maternal mortality rate (MMR) at around 154/100 000 live births. The international target for ‘developing’ countries was to reduce the MMR rate by three quarters by 2015, which would have meant a reduction to 38/100 000 live births. The aim of this dissertation is to examine how the democratic South African government (influenced heavily by global health thinking) has laboured to reduce that statistic. I analyse, using Foucauldian discourse analysis, all relevant health and maternal health policies, procedural documents and reports produced by and for the NDoH in the last 24 years. I draw on Foucauldian concepts, specifically those related to Foucault’s work on governmentality. In this dissertation I introduce a new perspective towards the maternal health practices implemented in South Africa, practices that have generally remained unquestioned, been perceived as self-evident, and thus often escaping critical analysis. Through an analysis of the intended operation of the public antenatal clinic (within the larger institutional system) I show how ‘development’ has come to operate as a truth regime in South Africa – facilitating the introduction of liberal governmentality (including some advanced liberal practices) into public health service provision.
- Full Text:
- Date Issued: 2019
- Authors: Du Plessis, Ulandi
- Date: 2019
- Subjects: South Africa. Department of Health (1994- ) , Maternal health services -- South Africa , Mothers -- Mortality -- South Africa , Prenatal care -- South Africa , African mothers -- Mortality -- South Africa
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/76552 , vital:30600
- Description: South Africa democratised in 1994. However, due to the discriminatory and segregationist character of the preceding regime, vast swathes of the country’s spaces and people entered the democratic period heavily deprived of essential government services. This was the case with health care in general, including maternal health care. There were also little to no national data available on maternal deaths, especially among the black population. One of the first tasks of the new National Department of Health (NDoH) was to target the high maternal mortality rate. The NDoH made maternal deaths notifiable by law and instituted auditing and information gathering systems in the health sector; health infrastructure was expanded exponentially, and maternal health care was made free. Despite this, the last 24 years have seen the maternal mortality escalate. The latest statistics show that between 1200 and 1300 women die in the South African public health sector each year during pregnancy and the puerperium. This puts the current institutional maternal mortality rate (MMR) at around 154/100 000 live births. The international target for ‘developing’ countries was to reduce the MMR rate by three quarters by 2015, which would have meant a reduction to 38/100 000 live births. The aim of this dissertation is to examine how the democratic South African government (influenced heavily by global health thinking) has laboured to reduce that statistic. I analyse, using Foucauldian discourse analysis, all relevant health and maternal health policies, procedural documents and reports produced by and for the NDoH in the last 24 years. I draw on Foucauldian concepts, specifically those related to Foucault’s work on governmentality. In this dissertation I introduce a new perspective towards the maternal health practices implemented in South Africa, practices that have generally remained unquestioned, been perceived as self-evident, and thus often escaping critical analysis. Through an analysis of the intended operation of the public antenatal clinic (within the larger institutional system) I show how ‘development’ has come to operate as a truth regime in South Africa – facilitating the introduction of liberal governmentality (including some advanced liberal practices) into public health service provision.
- Full Text:
- Date Issued: 2019
Intersectionality and complexity in the representation of ‘queer’ sexualities and genders in African women’s short fiction
- Authors: Du Preez, Jenny Boźena
- Date: 2019
- Subjects: Sexual minority culture , Sexual minorities' writings , African fiction -- Women authors -- History and criticism , Gender identity in literature , Short stories, South African , Feminism in literature , Political poetry , Eroticism in literature , Lesbianism in literature
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/119047 , vital:34697
- Description: This thesis sets out to contribute to the growing body of knowledge about queer sexualities and genders in Africa by examining their depiction in selected post-2000 African women’s short fiction written in English. Post-2000, the short story form has become the primary vehicle for queer representations by African women writers, and is thus an important development in the burgeoning body of queer literature by African writers. Broadly speaking, this literary formation can be defined as anti-homophobic, feminist and politically pragmatic. Using an intersectional lens, this thesis sets out to examine four significant strands in the political work these stories engage in. The chapters are structured around four main points of contention that have particular significance at the intersection of ‘queer’, ‘women’ and ‘Africa’. Firstly, I examine South African short stories that perform what I call queer conversations with history: imaginatively asserting a queer South African history, writing back against a male-dominated and heterosexist literary canon and, in doing so, contributing to the reimagination of the contemporary South African nation. Secondly, I analyse short stories from Africa that foreground the family, both as social formation and ideology. I examine how these stories ‘fracture’ this powerful and naturalised heterosexist concept by depicting the tensions and contradictions that queer characters experience in relation to family. Thirdly, I consider short stories from various African contexts that work to reconceptualise queer sexuality in relation to religious discourse in order to challenge homophobic and patriarchal religious authority. Finally, I examine queer, feminist erotic short stories by African women writers that challenges various colonialist, racist, sexist and lesbophobic discourses that have historically stifled the portrayal of sex and erotic experience between women.
- Full Text:
- Date Issued: 2019
- Authors: Du Preez, Jenny Boźena
- Date: 2019
- Subjects: Sexual minority culture , Sexual minorities' writings , African fiction -- Women authors -- History and criticism , Gender identity in literature , Short stories, South African , Feminism in literature , Political poetry , Eroticism in literature , Lesbianism in literature
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/119047 , vital:34697
- Description: This thesis sets out to contribute to the growing body of knowledge about queer sexualities and genders in Africa by examining their depiction in selected post-2000 African women’s short fiction written in English. Post-2000, the short story form has become the primary vehicle for queer representations by African women writers, and is thus an important development in the burgeoning body of queer literature by African writers. Broadly speaking, this literary formation can be defined as anti-homophobic, feminist and politically pragmatic. Using an intersectional lens, this thesis sets out to examine four significant strands in the political work these stories engage in. The chapters are structured around four main points of contention that have particular significance at the intersection of ‘queer’, ‘women’ and ‘Africa’. Firstly, I examine South African short stories that perform what I call queer conversations with history: imaginatively asserting a queer South African history, writing back against a male-dominated and heterosexist literary canon and, in doing so, contributing to the reimagination of the contemporary South African nation. Secondly, I analyse short stories from Africa that foreground the family, both as social formation and ideology. I examine how these stories ‘fracture’ this powerful and naturalised heterosexist concept by depicting the tensions and contradictions that queer characters experience in relation to family. Thirdly, I consider short stories from various African contexts that work to reconceptualise queer sexuality in relation to religious discourse in order to challenge homophobic and patriarchal religious authority. Finally, I examine queer, feminist erotic short stories by African women writers that challenges various colonialist, racist, sexist and lesbophobic discourses that have historically stifled the portrayal of sex and erotic experience between women.
- Full Text:
- Date Issued: 2019
Physicochemical properties and photodynamic therapy activities of indium and zinc phthalocyanine-nanoparticle conjugates
- Authors: Dube, Edith
- Date: 2019
- Subjects: Indium , Zinc , Phthalocyanines , Breast -- Cancer -- Photochemotherapy , Nanoparticles
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/76506 , vital:30589
- Description: The syntheses and characterization of symmetric and asymmetric Pcs functionalized at the peripheral position are reported. The Pcs contain either zinc or indium as central metals and have carboxyphenoxy, phenoxy propanoic acid, benzothiazole phenoxy, thiophine ethoxy or di-O-isopropylidene-α-D-glucopyranose as ring substituents. The Pcs were linked to NPs via an amide bond or through self-assembly. The photophysics and photochemistry of the Pcs were assessed when alone and with conjugates. All the studied Pcs showed good photophysicochemical behaviour with relatively high triplet and singlet oxygen quantum yields corresponding to their low fluorescence quantum yield. The Pcs with indium in their central cavity exhibited higher triplet and singlet oxygen quantum yields in comparison to their zinc counterparts due to the heavy–atom effect obtained from the former. Asymmetrical Pcs displayed higher triplet and singlet oxygen quantum yields than their symmetrical counterparts. The triplet quantum yield, generally increased on linkage to nanoparticles (NPs) due to the heavy–atom effect of gold and silver in NPs. The conjugates to gold nanospheres yielded higher triplet and singlet quantum yields than their gold nanotriangles counterparts due to the higher loading by the former probably encouraged by their relatively small particle size. The in vitro dark cytotoxicity and photodynamic therapy of selected Pc complexes and conjugates against MCF-7 cells was tested. All studied Pc complexes and conjugates showed minimum dark toxicity making them applicable for PDT. All complexes displayed poor phototoxicity with >50Îll viability at concentrations≤ 160μg/mL, however the conjugates showed<50% cell viabilityatconcentrations≤ 160μg/mLprobably due to the enhanced singlet oxygen quantum yield. The findings from this work show the importance of linking photosensitises such as phthalocyanines to metal nanoparticles for the enhancement ofsinglet oxygen quantum yield and ultimately the photodynamic effect.
- Full Text:
- Date Issued: 2019
- Authors: Dube, Edith
- Date: 2019
- Subjects: Indium , Zinc , Phthalocyanines , Breast -- Cancer -- Photochemotherapy , Nanoparticles
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/76506 , vital:30589
- Description: The syntheses and characterization of symmetric and asymmetric Pcs functionalized at the peripheral position are reported. The Pcs contain either zinc or indium as central metals and have carboxyphenoxy, phenoxy propanoic acid, benzothiazole phenoxy, thiophine ethoxy or di-O-isopropylidene-α-D-glucopyranose as ring substituents. The Pcs were linked to NPs via an amide bond or through self-assembly. The photophysics and photochemistry of the Pcs were assessed when alone and with conjugates. All the studied Pcs showed good photophysicochemical behaviour with relatively high triplet and singlet oxygen quantum yields corresponding to their low fluorescence quantum yield. The Pcs with indium in their central cavity exhibited higher triplet and singlet oxygen quantum yields in comparison to their zinc counterparts due to the heavy–atom effect obtained from the former. Asymmetrical Pcs displayed higher triplet and singlet oxygen quantum yields than their symmetrical counterparts. The triplet quantum yield, generally increased on linkage to nanoparticles (NPs) due to the heavy–atom effect of gold and silver in NPs. The conjugates to gold nanospheres yielded higher triplet and singlet quantum yields than their gold nanotriangles counterparts due to the higher loading by the former probably encouraged by their relatively small particle size. The in vitro dark cytotoxicity and photodynamic therapy of selected Pc complexes and conjugates against MCF-7 cells was tested. All studied Pc complexes and conjugates showed minimum dark toxicity making them applicable for PDT. All complexes displayed poor phototoxicity with >50Îll viability at concentrations≤ 160μg/mL, however the conjugates showed<50% cell viabilityatconcentrations≤ 160μg/mLprobably due to the enhanced singlet oxygen quantum yield. The findings from this work show the importance of linking photosensitises such as phthalocyanines to metal nanoparticles for the enhancement ofsinglet oxygen quantum yield and ultimately the photodynamic effect.
- Full Text:
- Date Issued: 2019
A physiological study on a commercial reef fish to quantify the relationship between exploitation and climate change resilience
- Authors: Duncan, Murray Ian
- Date: 2019
- Subjects: Chrysoblephus laticeps -- Climatic factors , Chrysoblephus laticeps -- Physiology , Sparidae -- South Africa -- Climatic factors , Reef fishes -- South Africa -- Climatic factors , Fish populations -- South Africa -- Climatic factors , Fish populations -- Measurement , Fish populations -- Monitoring , Fisheries -- South Africa -- Environmental aspects , Ocean temperature -- Physiological effect -- South Africa
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/76541 , vital:30599
- Description: The persistence of harvested fish populations in the Anthropocene will be determined, above all, by how they respond to the interacting effects of climate change and fisheries exploitation. Predicting how populations will respond to both these threats is essential for any adaptive and sustainable management strategy. The response of fish populations to climate change is underpinned by physiological rates and tolerances, and emerging evidence suggests there may be physiological-based selection in capture fisheries. By quantifying important physiological rates of a model species, the endemic seabream, Chrysoblephus laticeps, across ecologically relevant thermal gradients and from populations subjected to varying intensities of commercial exploitation, this thesis aimed to 1) provide the first physiologically grounded climate resilience assessment for a South African linefish species, and 2) elucidate whether exploitation can drive populations to less physiologically resilient states in response to climate change. To identify physiologically limiting sea temperatures and to determine if exploitation alters physiological trait distributions, an intermittent flow respirometry experiment was used to test the metabolic response of spatially protected and exploited populations of C. laticeps to acute thermal variability. Exploited populations showed reduced metabolic phenotype diversity, fewer high-performance aerobic scope phenotypes, and a significantly lower aerobic scope curve across all test temperatures. Although both populations maintained a relatively high aerobic scope across a wide thermal range, their metabolic rates were compromised when extreme cold events were simulated (8 °C), suggesting that predicted future increases in upwelling frequency and intensity may be the primary limiting factor in a more thermally variable future ocean. The increment widths of annuli in the otoliths of C. laticeps from contemporary and historic collections were measured, as a proxy for the annual growth rate of exploited and protected populations. Hierarchical mixed models were used to partition growth variation within and among individuals and ascribe growth to intrinsic and extrinsic effects. The best model for the protected population indicated that the growth response of C. laticeps was poorer during years characterised by a high cumulative upwelling intensity, and better during years characterised by higher mean autumn sea surface temperatures. The exploited population growth chronology was too short to identify an extrinsic growth driver. The growth results again highlight the role of thermal variability in modulating the response of C. laticeps to its ambient environment and indicate that the predicted increases in upwelling frequency and intensity may constrain future growth rates of this species. A metabolic index (ϕ), representing the ratio of O2 supply to demand at various temperatures and oxygen concentrations, was estimated for exploited and protected populations of C. laticeps and used to predict future distribution responses. There was no difference in the laboratory calibrations of ϕ between populations, and all data was subsequently combined into a single piecewise (12 °C) calibrated ϕ model. To predict the distribution of C. laticeps, ϕ was projected across a high-resolution ocean model of the South African coastal zone, and a species distribution model implemented using the random forest algorithm and C. laticeps occurrence points. The future distribution of C. laticeps was estimated by predicting trained models across ocean model projections up to 2100. The best predictor of C. laticeps’ current distribution was minimum monthly ϕ and future predictions indicated only a slight range contraction on either edge of C. laticeps’ distribution by 2100. In order to provide policy makers, currently developing climate change management frameworks for South Africa’s ocean, with a usable output, the results of all research chapters were combined into a marine spatial model. The spatial model identified areas where C. laticeps is predicted to be resilient to climate change in terms of physiology, growth and distribution responses, which can then be prioritised for adaptation measures, such as spatial protection from exploitation. While these results are specific to C. laticeps, the methodology developed to identify areas of climate resilience has broad applications across taxa. From a global perspective, perhaps the most salient points to consider from this case study are the evidence of selective exploitation on physiological traits and the importance of environmental variability, rather than long-term mean climate changes, in affecting organism performance. These ideas are congruent with the current paradigm shift in how we think of the ocean, selective fisheries, and how they relate to organism climate resilience.
- Full Text:
- Date Issued: 2019
- Authors: Duncan, Murray Ian
- Date: 2019
- Subjects: Chrysoblephus laticeps -- Climatic factors , Chrysoblephus laticeps -- Physiology , Sparidae -- South Africa -- Climatic factors , Reef fishes -- South Africa -- Climatic factors , Fish populations -- South Africa -- Climatic factors , Fish populations -- Measurement , Fish populations -- Monitoring , Fisheries -- South Africa -- Environmental aspects , Ocean temperature -- Physiological effect -- South Africa
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/76541 , vital:30599
- Description: The persistence of harvested fish populations in the Anthropocene will be determined, above all, by how they respond to the interacting effects of climate change and fisheries exploitation. Predicting how populations will respond to both these threats is essential for any adaptive and sustainable management strategy. The response of fish populations to climate change is underpinned by physiological rates and tolerances, and emerging evidence suggests there may be physiological-based selection in capture fisheries. By quantifying important physiological rates of a model species, the endemic seabream, Chrysoblephus laticeps, across ecologically relevant thermal gradients and from populations subjected to varying intensities of commercial exploitation, this thesis aimed to 1) provide the first physiologically grounded climate resilience assessment for a South African linefish species, and 2) elucidate whether exploitation can drive populations to less physiologically resilient states in response to climate change. To identify physiologically limiting sea temperatures and to determine if exploitation alters physiological trait distributions, an intermittent flow respirometry experiment was used to test the metabolic response of spatially protected and exploited populations of C. laticeps to acute thermal variability. Exploited populations showed reduced metabolic phenotype diversity, fewer high-performance aerobic scope phenotypes, and a significantly lower aerobic scope curve across all test temperatures. Although both populations maintained a relatively high aerobic scope across a wide thermal range, their metabolic rates were compromised when extreme cold events were simulated (8 °C), suggesting that predicted future increases in upwelling frequency and intensity may be the primary limiting factor in a more thermally variable future ocean. The increment widths of annuli in the otoliths of C. laticeps from contemporary and historic collections were measured, as a proxy for the annual growth rate of exploited and protected populations. Hierarchical mixed models were used to partition growth variation within and among individuals and ascribe growth to intrinsic and extrinsic effects. The best model for the protected population indicated that the growth response of C. laticeps was poorer during years characterised by a high cumulative upwelling intensity, and better during years characterised by higher mean autumn sea surface temperatures. The exploited population growth chronology was too short to identify an extrinsic growth driver. The growth results again highlight the role of thermal variability in modulating the response of C. laticeps to its ambient environment and indicate that the predicted increases in upwelling frequency and intensity may constrain future growth rates of this species. A metabolic index (ϕ), representing the ratio of O2 supply to demand at various temperatures and oxygen concentrations, was estimated for exploited and protected populations of C. laticeps and used to predict future distribution responses. There was no difference in the laboratory calibrations of ϕ between populations, and all data was subsequently combined into a single piecewise (12 °C) calibrated ϕ model. To predict the distribution of C. laticeps, ϕ was projected across a high-resolution ocean model of the South African coastal zone, and a species distribution model implemented using the random forest algorithm and C. laticeps occurrence points. The future distribution of C. laticeps was estimated by predicting trained models across ocean model projections up to 2100. The best predictor of C. laticeps’ current distribution was minimum monthly ϕ and future predictions indicated only a slight range contraction on either edge of C. laticeps’ distribution by 2100. In order to provide policy makers, currently developing climate change management frameworks for South Africa’s ocean, with a usable output, the results of all research chapters were combined into a marine spatial model. The spatial model identified areas where C. laticeps is predicted to be resilient to climate change in terms of physiology, growth and distribution responses, which can then be prioritised for adaptation measures, such as spatial protection from exploitation. While these results are specific to C. laticeps, the methodology developed to identify areas of climate resilience has broad applications across taxa. From a global perspective, perhaps the most salient points to consider from this case study are the evidence of selective exploitation on physiological traits and the importance of environmental variability, rather than long-term mean climate changes, in affecting organism performance. These ideas are congruent with the current paradigm shift in how we think of the ocean, selective fisheries, and how they relate to organism climate resilience.
- Full Text:
- Date Issued: 2019
The performance and preference of a specialist herbivore, Catorhintha schaffneri (Coreidae), on its polytypic host plant, Pereskia aculeata (Cactaceae)
- Authors: Egbon, Ikponmwosa Nathaniel
- Date: 2019
- Subjects: Insects and biological pest control agents -- South Africa , Pereskia -- Biological control -- South Africa , Cactus -- Biological control -- South Africa , Coreida-- South Africa , Invasive plants -- Biological control -- South Africa , Catorhintha schaffneri
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/68250 , vital:29223
- Description: Plant species moved beyond their natural ranges may be liberated into enemy-free spaces, where they increase resource allocation to fitness, rather than defence against natural enemies, and become invasive as suggested by the Evolution of Increased Competitive Ability (EICA) Hypothesis. Several cacti are notable invaders and are targeted for biological control. The leafy cactus, Pereskia aculeata Miller, introduced into South Africa from South America, has become a target for biological control after becoming invasive. The absence of natural enemies of P. aculeata in the introduced range may be the reason for its invasiveness. This thesis seeks to investigate the role of the evolution of increased competitive ability (enemy release) as the probable driver of P. aculeata’s success, and ascertain how the plant’s intraspecific variation influences the impact, fitness of, and preference by its biological control agent, Catorhintha schaffneri Brailovsky and Garcia (Coreidae), in South Africa. Enemy release and evolution of traits in P. aculeata were examined by quantifying plant growth parameters of fifteen genotypes of P. aculeata from both the native and invaded distribution of the plant. Ten genotypes of P. aculeata were used in testing the effect of agent herbivory (impact and damage) under similar conditions. These studies indicated that most invaded-range genotypes were more vigorous than the native genotypes. Rapid growth may account for the quick access of invasive genotypes of P. aculeata to tree canopies. Catorhintha schaffneri damage varied between genotypes but differences in the damage and impact from the agent could not be explained by whether the plant originated in the introduced or native distribution. In sum, while the growth of the invasive genotypes largely conforms to the EICA hypothesis, the impact of C. schaffneri did not support the hypothesis. The influence of host variation in P. aculeata on the fitness of C. schaffneri within the context of local adaptation to plant genotypes from different localities was tested using agent survival, stage-specific and total developmental time, and the extent of damage to ten host genotypes. Maw’s Host Suitability Index (HIS) and Dobie’s Susceptibility Index (DSI) showed the preference by and performance of C. schaffneri on the different genotypes of the plant. Catorhintha schaffneri survived to the adult stage on 70% of genotypes tested. Evidence consistent with the assumption that C. schaffneri would be fitter on the native genotypes than the invasive genotypes due to local adaptation was not found. In addition, there was no evidence in support of fitter agents on the invasive genotypes than on the native genotypes as proposed by EICA hypothesis. Catorhintha schaffneri developed equally well on the invasive genotypes of P. aculeata as on the native genotypes. To establish whether host variation would affect diet selection by C. schaffneri, both nymphs and adults were examined in paired-choice and multiple-choice trials. The nymphs and adults chose their hosts regardless of host genotype differences. The agent may be good at selecting good succulent shoots from bad shoots, but is incapable of distinguishing a good host genotype from a poorer one. This thesis shows, therefore, that P. aculeata and its array of genotypes in South Africa could be effectively controlled by C. schaffneri, as it has the potential to suitably utilise and impact the different genotypes of the weed in South Africa with neither any demonstrable preference nor local adaptation for the native genotypes. Consequently, the use of C. schaffneri, as a biological control agent in the weed biological control programme of P. aculeata remains promising, as the agent is insensitive to the intraspecific variation of the invasive host plants.
- Full Text:
- Date Issued: 2019
- Authors: Egbon, Ikponmwosa Nathaniel
- Date: 2019
- Subjects: Insects and biological pest control agents -- South Africa , Pereskia -- Biological control -- South Africa , Cactus -- Biological control -- South Africa , Coreida-- South Africa , Invasive plants -- Biological control -- South Africa , Catorhintha schaffneri
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/68250 , vital:29223
- Description: Plant species moved beyond their natural ranges may be liberated into enemy-free spaces, where they increase resource allocation to fitness, rather than defence against natural enemies, and become invasive as suggested by the Evolution of Increased Competitive Ability (EICA) Hypothesis. Several cacti are notable invaders and are targeted for biological control. The leafy cactus, Pereskia aculeata Miller, introduced into South Africa from South America, has become a target for biological control after becoming invasive. The absence of natural enemies of P. aculeata in the introduced range may be the reason for its invasiveness. This thesis seeks to investigate the role of the evolution of increased competitive ability (enemy release) as the probable driver of P. aculeata’s success, and ascertain how the plant’s intraspecific variation influences the impact, fitness of, and preference by its biological control agent, Catorhintha schaffneri Brailovsky and Garcia (Coreidae), in South Africa. Enemy release and evolution of traits in P. aculeata were examined by quantifying plant growth parameters of fifteen genotypes of P. aculeata from both the native and invaded distribution of the plant. Ten genotypes of P. aculeata were used in testing the effect of agent herbivory (impact and damage) under similar conditions. These studies indicated that most invaded-range genotypes were more vigorous than the native genotypes. Rapid growth may account for the quick access of invasive genotypes of P. aculeata to tree canopies. Catorhintha schaffneri damage varied between genotypes but differences in the damage and impact from the agent could not be explained by whether the plant originated in the introduced or native distribution. In sum, while the growth of the invasive genotypes largely conforms to the EICA hypothesis, the impact of C. schaffneri did not support the hypothesis. The influence of host variation in P. aculeata on the fitness of C. schaffneri within the context of local adaptation to plant genotypes from different localities was tested using agent survival, stage-specific and total developmental time, and the extent of damage to ten host genotypes. Maw’s Host Suitability Index (HIS) and Dobie’s Susceptibility Index (DSI) showed the preference by and performance of C. schaffneri on the different genotypes of the plant. Catorhintha schaffneri survived to the adult stage on 70% of genotypes tested. Evidence consistent with the assumption that C. schaffneri would be fitter on the native genotypes than the invasive genotypes due to local adaptation was not found. In addition, there was no evidence in support of fitter agents on the invasive genotypes than on the native genotypes as proposed by EICA hypothesis. Catorhintha schaffneri developed equally well on the invasive genotypes of P. aculeata as on the native genotypes. To establish whether host variation would affect diet selection by C. schaffneri, both nymphs and adults were examined in paired-choice and multiple-choice trials. The nymphs and adults chose their hosts regardless of host genotype differences. The agent may be good at selecting good succulent shoots from bad shoots, but is incapable of distinguishing a good host genotype from a poorer one. This thesis shows, therefore, that P. aculeata and its array of genotypes in South Africa could be effectively controlled by C. schaffneri, as it has the potential to suitably utilise and impact the different genotypes of the weed in South Africa with neither any demonstrable preference nor local adaptation for the native genotypes. Consequently, the use of C. schaffneri, as a biological control agent in the weed biological control programme of P. aculeata remains promising, as the agent is insensitive to the intraspecific variation of the invasive host plants.
- Full Text:
- Date Issued: 2019
A leadership development model to enhance ethical governance in South Africa
- Authors: Els, Ryno Juan
- Date: 2019
- Subjects: Leadership -- South Africa , Public administration -- Moral and ethical aspects Corporate governance Business ethics -- South Africa Africa Professional ethics Organizational behavior -- Moral and ethical aspects
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/39863 , vital:35489
- Description: From the United States of America’s White House to the Vatican in Vatican City, from Harare, Zimbabwe to the Union buildings in South Africa, to large organisations like Volkswagen, BP and KPMG, leadership failures are prolific. Globalised and local leadership failures and scandals are plagued by narcissistic, toxic, corrupt and dishonest behaviour by heads of state, CEOs and clergy. The effect of executive leadership failures is that they set the tone for a corrupt culture that spirals negatively down to grass-roots level. Unethical leadership in organisations manifests in various ways including misconduct, deception and cheating. Apart from regular exposés of leadership scandals globally, there has been a notable increase in ethical leadership derailments caused by unethical behaviour. The question is why leaders, who are considered to understand value-based morality, engage in unethical behaviour when confronted with the opportunity. In recent, empirical research in behavioural ethics and moral psychology, it was found that morally sound leaders often indulge in unethical behaviour. Unethical leadership behaviour includes misdemeanours in tax returns, overstating performance, inflating business expense accounts, involvement in corruption, counter-productive work behaviour, being morally disengaged and being untruthful during negotiations. Recent research indicates that unethical leadership leads to an increase in poor governance and propels vicious cycles that have a negative impact on human development, economic growth and the environment. This research study includes traditional and contemporary leadership theories that have been evaluated as well as an in-depth discussion of the necessity and importance of ethical governance. An innovative, ethical leadership development model has been designed and aligned with servant, ethical, authentic and integrated leadership styles where spiritual, cultural and emotional intelligences play a significant role in leadership maturity. A fresh perspective on the King IV Report (2016) as an international benchmark together with other authoritative literature and case studies of unethical governance have been discussed to shed light on the latest leadership theories and ethics in the 21st century. The findings of this study have been tested statistically by means of structural equation modelling (SEM). The findings confirmed empirically that accountability, stakeholders’ interests and the regulatory environment need to be implemented by ethical leaders in order to enhance ethical governance. The lack of a practical, outcome-based, leadership development model provided an opportunity to develop an ethical leadership development model that would have a positive impact on ethical governance, thereby contributing to the body of knowledge.
- Full Text:
- Date Issued: 2019
- Authors: Els, Ryno Juan
- Date: 2019
- Subjects: Leadership -- South Africa , Public administration -- Moral and ethical aspects Corporate governance Business ethics -- South Africa Africa Professional ethics Organizational behavior -- Moral and ethical aspects
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/39863 , vital:35489
- Description: From the United States of America’s White House to the Vatican in Vatican City, from Harare, Zimbabwe to the Union buildings in South Africa, to large organisations like Volkswagen, BP and KPMG, leadership failures are prolific. Globalised and local leadership failures and scandals are plagued by narcissistic, toxic, corrupt and dishonest behaviour by heads of state, CEOs and clergy. The effect of executive leadership failures is that they set the tone for a corrupt culture that spirals negatively down to grass-roots level. Unethical leadership in organisations manifests in various ways including misconduct, deception and cheating. Apart from regular exposés of leadership scandals globally, there has been a notable increase in ethical leadership derailments caused by unethical behaviour. The question is why leaders, who are considered to understand value-based morality, engage in unethical behaviour when confronted with the opportunity. In recent, empirical research in behavioural ethics and moral psychology, it was found that morally sound leaders often indulge in unethical behaviour. Unethical leadership behaviour includes misdemeanours in tax returns, overstating performance, inflating business expense accounts, involvement in corruption, counter-productive work behaviour, being morally disengaged and being untruthful during negotiations. Recent research indicates that unethical leadership leads to an increase in poor governance and propels vicious cycles that have a negative impact on human development, economic growth and the environment. This research study includes traditional and contemporary leadership theories that have been evaluated as well as an in-depth discussion of the necessity and importance of ethical governance. An innovative, ethical leadership development model has been designed and aligned with servant, ethical, authentic and integrated leadership styles where spiritual, cultural and emotional intelligences play a significant role in leadership maturity. A fresh perspective on the King IV Report (2016) as an international benchmark together with other authoritative literature and case studies of unethical governance have been discussed to shed light on the latest leadership theories and ethics in the 21st century. The findings of this study have been tested statistically by means of structural equation modelling (SEM). The findings confirmed empirically that accountability, stakeholders’ interests and the regulatory environment need to be implemented by ethical leaders in order to enhance ethical governance. The lack of a practical, outcome-based, leadership development model provided an opportunity to develop an ethical leadership development model that would have a positive impact on ethical governance, thereby contributing to the body of knowledge.
- Full Text:
- Date Issued: 2019
The trophic and spatial ecology of a sympatric dasyatid community at a remote Atoll, Seychelles
- Authors: Elston, Chantel
- Date: 2019
- Subjects: Dasyatidae -- Seychelles -- Ecology , Rays (Fishes) -- Seychelles -- Ecology , Ecology -- Seychelles , Dasyatidae -- Seychelles -- Conservation , Pastinachus sephen , Urogymnus granulatus , Urogymnus asperrimus
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/95756 , vital:31196 , DOI https://doi.org/10.21504/10962/95756
- Description: Batoid populations are declining globally but the paucity of information makes management or conservation efforts difficult. Additionally, batoids are mesopredators and are hypothesised to play important ecological roles, but a comprehensive understanding of these roles is also limited. Therefore, information on batoid habitat use, foraging ecology, and resource partitioning is needed. St. Joseph Atoll is a relatively pristine ecosystem that hosts a sympatric dasyatid community (Pastinachus sephen, Urogymnus granulatus, and U. asperrimus). Passive acoustic telemetry identified high levels of long-term site affinity by both juvenile and adult dasyatids to St. Joseph Atoll. Dispersal from the atoll by larger juveniles was also evident. Juveniles displayed restricted horizontal movements in the atoll, but the extent of these movements differed seasonally. Stomach content and stable isotope analyses identified inter-specific prey partitioning (P. sephen juveniles were mollusc specialists and U. granulatus juveniles were crustacean specialists) and intra-specific prey partitioning. Juveniles were reliant upon a seagrass-based food web, whereas adults were reliant on phytoplankton-based food web. Adults fed at higher trophic levels compared to juveniles (mean of 4.6 and 3.4 respectively). Juvenile dasyatids preferentially selected the shallow reef at habitat of the atoll, where there was no evidence for inter-specific habitat partitioning (individuals co-occurred randomly with con-and hetero-specifics). Conversely, resident adults were more reliant on the deeper lagoon. Juveniles selected the reef at habitat likely because it provided refuge from predation and foraging opportunities. However, juveniles were also detected in the lagoon habitat and this appeared to be necessitated by physical factors as they were detected more frequently in the lagoon at low tides and when temperatures on the reef fats became too warm or too cold. All results together suggest that St. Joseph Atoll is a nursery area for these dasyatids. Juveniles may be limited by resources as prey was partitioned between species. However, top-down control by larger sharks was likely a significant influence on habitat selection, as was the physical effects of tide and temperature. Finally, St. Joseph Atoll is suitable for the designation of a Marine Protected Area, which would likely confer high conservation benefits to this dasyatid community.
- Full Text:
- Date Issued: 2019
- Authors: Elston, Chantel
- Date: 2019
- Subjects: Dasyatidae -- Seychelles -- Ecology , Rays (Fishes) -- Seychelles -- Ecology , Ecology -- Seychelles , Dasyatidae -- Seychelles -- Conservation , Pastinachus sephen , Urogymnus granulatus , Urogymnus asperrimus
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/95756 , vital:31196 , DOI https://doi.org/10.21504/10962/95756
- Description: Batoid populations are declining globally but the paucity of information makes management or conservation efforts difficult. Additionally, batoids are mesopredators and are hypothesised to play important ecological roles, but a comprehensive understanding of these roles is also limited. Therefore, information on batoid habitat use, foraging ecology, and resource partitioning is needed. St. Joseph Atoll is a relatively pristine ecosystem that hosts a sympatric dasyatid community (Pastinachus sephen, Urogymnus granulatus, and U. asperrimus). Passive acoustic telemetry identified high levels of long-term site affinity by both juvenile and adult dasyatids to St. Joseph Atoll. Dispersal from the atoll by larger juveniles was also evident. Juveniles displayed restricted horizontal movements in the atoll, but the extent of these movements differed seasonally. Stomach content and stable isotope analyses identified inter-specific prey partitioning (P. sephen juveniles were mollusc specialists and U. granulatus juveniles were crustacean specialists) and intra-specific prey partitioning. Juveniles were reliant upon a seagrass-based food web, whereas adults were reliant on phytoplankton-based food web. Adults fed at higher trophic levels compared to juveniles (mean of 4.6 and 3.4 respectively). Juvenile dasyatids preferentially selected the shallow reef at habitat of the atoll, where there was no evidence for inter-specific habitat partitioning (individuals co-occurred randomly with con-and hetero-specifics). Conversely, resident adults were more reliant on the deeper lagoon. Juveniles selected the reef at habitat likely because it provided refuge from predation and foraging opportunities. However, juveniles were also detected in the lagoon habitat and this appeared to be necessitated by physical factors as they were detected more frequently in the lagoon at low tides and when temperatures on the reef fats became too warm or too cold. All results together suggest that St. Joseph Atoll is a nursery area for these dasyatids. Juveniles may be limited by resources as prey was partitioned between species. However, top-down control by larger sharks was likely a significant influence on habitat selection, as was the physical effects of tide and temperature. Finally, St. Joseph Atoll is suitable for the designation of a Marine Protected Area, which would likely confer high conservation benefits to this dasyatid community.
- Full Text:
- Date Issued: 2019
Selected stakeholders’ views on the use of tablet computers in learning and teaching – a South African case study at a university
- Fernandez, Simon Christopher
- Authors: Fernandez, Simon Christopher
- Date: 2019
- Subjects: Computer-assisted instruction Tablet computers Educational technology
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10353/15903 , vital:40553
- Description: The popularity of mobile technologies has greatly influenced the people of all ages, especially adolescents. Tablet computers as part of mobile technologies, were launched in colleges and universities in many countries to supplement and complement learning and teaching. However, research reports based on the effectiveness of the use of tablet computers in higher education institutions in South Africa’s Eastern Cape Province are scarce. In order to address the deficiency, this study examined the views of stakeholders such as students, lecturers and managers on the use of tablet computers for learning and teaching in one of the Eastern Cape universities. The research adopted the Post-Positivist paradigm and mixed method approach. The theoretical frameworks were Constructivism and Technological Pedagogical Content Knowledge. The sample consisted of (a) 155 students from a population of 254 extended-stream National Diploma students in Information and Communication Technology and National Diploma Electrical Engineering cohorts; (b) 14 lecturers from a relevant population of 25; and, (c) 16 managers from a population of 20. Three separate questionnaires as well as interview protocols for each of the stakeholder cohorts provided the core data. All members in the sample were surveyed. The researcher opted to be an outsider and received assistance from a few qualified trained academics to administer the questionnaire to students in different cohorts in order to minimise data bias. Only 18 students, five lecturers and nine managers were interviewed. Quantitative data were captured manually into Statistical Package for Social Sciences (version 24) and they were analysed using descriptive and inferential analysis: Analysis of Variance and Independent Samples t-test. Qualitative data were transcribed and analysed using thematic analysis to generate major themes and sub themes for the sub-research questions. Main strengths of using tablets from the findings of the study were (a) tablets motivated students in learning and lecturers in teaching (b) students understood the different styles of learning (c) enhanced students’ engagement and collaboration in learning. Main weakness of using tablets were students’ use of tablets for personal work and social networking during class hours was causing distractions to lecturers and other students. Generally, the evidence shows that strengths were greater than the weaknesses. It should also be noted that all stakeholders were positive and not statistically significantly different from each other in their views towards the use of tablets for learning and teaching in university classroom. However, students had views different from lecturers on the advantages and disadvantages of using tablets. The variance could be due to new students or new lecturers’ ignorance in the effective use of tablets and this might change as their familiarity in the use of the device improves. The research report makes a few recommendations which include training to all students and lecturers on the effective use of tablet computers for learning and teaching and installation of relevant applications before the commencement of each academic year. Moreover, the Information and communication technology technical staff must prevent students from visiting unwanted and restricted sites by keeping a network based tracker and blocker software application.
- Full Text:
- Date Issued: 2019
- Authors: Fernandez, Simon Christopher
- Date: 2019
- Subjects: Computer-assisted instruction Tablet computers Educational technology
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10353/15903 , vital:40553
- Description: The popularity of mobile technologies has greatly influenced the people of all ages, especially adolescents. Tablet computers as part of mobile technologies, were launched in colleges and universities in many countries to supplement and complement learning and teaching. However, research reports based on the effectiveness of the use of tablet computers in higher education institutions in South Africa’s Eastern Cape Province are scarce. In order to address the deficiency, this study examined the views of stakeholders such as students, lecturers and managers on the use of tablet computers for learning and teaching in one of the Eastern Cape universities. The research adopted the Post-Positivist paradigm and mixed method approach. The theoretical frameworks were Constructivism and Technological Pedagogical Content Knowledge. The sample consisted of (a) 155 students from a population of 254 extended-stream National Diploma students in Information and Communication Technology and National Diploma Electrical Engineering cohorts; (b) 14 lecturers from a relevant population of 25; and, (c) 16 managers from a population of 20. Three separate questionnaires as well as interview protocols for each of the stakeholder cohorts provided the core data. All members in the sample were surveyed. The researcher opted to be an outsider and received assistance from a few qualified trained academics to administer the questionnaire to students in different cohorts in order to minimise data bias. Only 18 students, five lecturers and nine managers were interviewed. Quantitative data were captured manually into Statistical Package for Social Sciences (version 24) and they were analysed using descriptive and inferential analysis: Analysis of Variance and Independent Samples t-test. Qualitative data were transcribed and analysed using thematic analysis to generate major themes and sub themes for the sub-research questions. Main strengths of using tablets from the findings of the study were (a) tablets motivated students in learning and lecturers in teaching (b) students understood the different styles of learning (c) enhanced students’ engagement and collaboration in learning. Main weakness of using tablets were students’ use of tablets for personal work and social networking during class hours was causing distractions to lecturers and other students. Generally, the evidence shows that strengths were greater than the weaknesses. It should also be noted that all stakeholders were positive and not statistically significantly different from each other in their views towards the use of tablets for learning and teaching in university classroom. However, students had views different from lecturers on the advantages and disadvantages of using tablets. The variance could be due to new students or new lecturers’ ignorance in the effective use of tablets and this might change as their familiarity in the use of the device improves. The research report makes a few recommendations which include training to all students and lecturers on the effective use of tablet computers for learning and teaching and installation of relevant applications before the commencement of each academic year. Moreover, the Information and communication technology technical staff must prevent students from visiting unwanted and restricted sites by keeping a network based tracker and blocker software application.
- Full Text:
- Date Issued: 2019
Social entrepreneurship and poverty reduction in South Africa, the case Eastern Cape Province
- Fiseha, Gebregziabher Gebreyseus
- Authors: Fiseha, Gebregziabher Gebreyseus
- Date: 2019
- Subjects: Poverty Alleviation
- Language: English
- Type: Thesis , Doctoral , PhD(Dev)
- Identifier: http://hdl.handle.net/10353/18919 , vital:42998
- Description: Globally, poverty is a major social problem. Billions of people in developing countries, particularly sub-Saharan African countries including South Africa, continue to live in extreme poverty without access to basic needs (food, shelter, clean water and sanitation, health and education).The Eastern Cape Province has the highest number of the poor people in South Africa. The government strategies and policies to address the magnitude of poverty seem unlikely to lift the majority from poverty. Recently, however, social entrepreneurship has been recognized as the most important instrument in addressing the challenges of development (poverty, unemployment and inequality). Hence, this study was conducted to examine the role of social entrepreneurship in poverty reduction in Eastern Cape Province. A mixed research method was employed to achieve this objective. The population of the study targeted social entrepreneurs and their beneficiaries in Eastern Cape Province. The data were collected using semi-structured questionnaire from 265 social entrepreneurs and 120 social entrepreneurship beneficiaries. The participants were selected through purposive sampling technique since the population of social entrepreneurs and social entrepreneurship beneficiaries in the Eastern Cape Province is not well determined. The descriptive statistics and inferential statistics were used to analyze the data. The findings revealed that social entrepreneurship plays a crucial role in poverty reduction in Eastern Cape Province through creating employment opportunities, skill development, availability of goods and services such as financial loans. Therefore, the support for entrepreneurship culture is important for social entrepreneurship growth in order to enhance its contribution to poverty reduction. The study recommends that the government of South Africa and other vi relevant stakeholders should create conducive environment for social entrepreneurs to flourish and grow in the country to reduce poverty significantly. The growth of social entrepreneurship can lead to substantial benefits for the marginalized and vulnerable segments of the society
- Full Text:
- Date Issued: 2019
- Authors: Fiseha, Gebregziabher Gebreyseus
- Date: 2019
- Subjects: Poverty Alleviation
- Language: English
- Type: Thesis , Doctoral , PhD(Dev)
- Identifier: http://hdl.handle.net/10353/18919 , vital:42998
- Description: Globally, poverty is a major social problem. Billions of people in developing countries, particularly sub-Saharan African countries including South Africa, continue to live in extreme poverty without access to basic needs (food, shelter, clean water and sanitation, health and education).The Eastern Cape Province has the highest number of the poor people in South Africa. The government strategies and policies to address the magnitude of poverty seem unlikely to lift the majority from poverty. Recently, however, social entrepreneurship has been recognized as the most important instrument in addressing the challenges of development (poverty, unemployment and inequality). Hence, this study was conducted to examine the role of social entrepreneurship in poverty reduction in Eastern Cape Province. A mixed research method was employed to achieve this objective. The population of the study targeted social entrepreneurs and their beneficiaries in Eastern Cape Province. The data were collected using semi-structured questionnaire from 265 social entrepreneurs and 120 social entrepreneurship beneficiaries. The participants were selected through purposive sampling technique since the population of social entrepreneurs and social entrepreneurship beneficiaries in the Eastern Cape Province is not well determined. The descriptive statistics and inferential statistics were used to analyze the data. The findings revealed that social entrepreneurship plays a crucial role in poverty reduction in Eastern Cape Province through creating employment opportunities, skill development, availability of goods and services such as financial loans. Therefore, the support for entrepreneurship culture is important for social entrepreneurship growth in order to enhance its contribution to poverty reduction. The study recommends that the government of South Africa and other vi relevant stakeholders should create conducive environment for social entrepreneurs to flourish and grow in the country to reduce poverty significantly. The growth of social entrepreneurship can lead to substantial benefits for the marginalized and vulnerable segments of the society
- Full Text:
- Date Issued: 2019
The anti-inflammatory effects of Sutherlandia Frutescens in a cell and animal model
- Authors: Fortuin-Seedat, Maleeha
- Date: 2019
- Subjects: Medicinal Plant -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/44617 , vital:38167
- Description: The South African medicinal plant, Sutherlandia frutescens has anti-diabetic, antiinflammatory and antioxidant properties. Many of the mediators of inflammation are also involved in obesity and diabetes. Furthermore, T2D can either induce inflammation, or exacerbate the inflammatory response by maintaining imbalances between pro-and anti-inflammatory mediators. Two macrophage sub-populations involved in the regulation of immune responses have been defined. These are classically activated macrophages (M1) which stimulate inflammation, and alternatively activated macrophages (M2), which show anti-inflammatory activity. Therefore it is hypothesised that S. frutescens can potentially regulate macrophage polarization states which, in turn, influence metabolic immunomodulatory processes. The aims of this study were firstly to identify the mechanisms(s) by which S. frutescens could improve the low-grade inflammatory status in obese and T2D individuals using a transgenic mouse model of obesity, and secondly to determine the immunomodulating properties of S. frutescens in the human monocytic THP-1 cell line. Groups of nine week old male db/db mice were gavaged daily with water (vehicle control), Vildagliptin (10mL kg-1)(positive medication control) or hot aqueous S. frutescens extract at concentrations of 5mg, 50mg, 250mg kg-1 for 4 weeks. Body weight and fasting plasma glucose levels were determined weekly. The potential for hot aqueous S. frutescens extract to lower postprandial hyperglycaemia and promote insulin sensitivity was determined by an oral glucose tolerance test (OGTT) after a 16 hour fast, and an insulin radioimmunoassay (RIA) after a 4 hour fast before termination. After 4 weeks of hot aqueous S. frutescens treatment the total percentage body weight of 13 week old db/db mice was reduced, but hyperglycaemia was not prevented. Human THP-1 monocytes were stimulated to differentiate into macrophages with phorbol-12myristate-13acetate (PMA) and cultured under pro-inflammatory conditions (M1) or anti-inflammatory conditions (M2). Cell viability and anti-proliferative effects of LPS and S. frutescens extracts were determined. The effect of hot aqueous and ethanolic S. frutescens extracts on M1 and M2 macrophage cell surface markers was investigated by flow cytometry using CD86 (M1) and CD206 (M2). The effect of the S. frutescens extracts on three signalling pathways and a pro-inflammatory mediator activated in an LPS-induced inflammatory response were determined using Western blotting. Changes in mRNA gene expression levels of downstream transcription factors, cytokines and chemokines associated with M1 and M2 polarised macrophages were investigated using qRT-PCR. Both ethanolic and hot aqueous S. frutescens extracts reduced cytotoxicity caused by LPS. S. frutescens extracts alone did not alter cell viability. Furthermore, both hot and ethanolic S. frutescens extracts reduced expression of the M1 marker CD86 and nonsignificantly induced expression of an M2 marker CD206, following LPS stimulation. Following M2 induction, the M1 and M2 cell surface markers were reverted to baseline M0 macrophage expression by both S. frutescens extracts. The S. frutescens extracts mediated immune-regulatory activity through suppression of the pro-inflammatory p38 MAPK and NFκB signalling pathways and regulated apoptosis through the ERK1/2 pathway. The hot aqueous S. frutescens extract exerted anti-inflammatory effects through the IKK pathway and/ or GSK3β signalling pathway. This thesis demonstrates that S. frutescens promotes macrophage homeostasis by maintaining the balance between M1 and M2 macrophages during pro-and antiinflammatory immune responses. The regulation may occur during the activation and polarization process, via rapid deactivation of M1 macrophages and a decrease in need for macrophages to switch to an M2 phenotype. Furthermore S. frutescens is hypothesised to play a role in the regulation of the GSK3β signalling which plays a central role in regulating inflammation associated with pathophysiological conditions such as IR, T2D and obesity via the PI3K/Akt pathway.
- Full Text:
- Date Issued: 2019
- Authors: Fortuin-Seedat, Maleeha
- Date: 2019
- Subjects: Medicinal Plant -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/44617 , vital:38167
- Description: The South African medicinal plant, Sutherlandia frutescens has anti-diabetic, antiinflammatory and antioxidant properties. Many of the mediators of inflammation are also involved in obesity and diabetes. Furthermore, T2D can either induce inflammation, or exacerbate the inflammatory response by maintaining imbalances between pro-and anti-inflammatory mediators. Two macrophage sub-populations involved in the regulation of immune responses have been defined. These are classically activated macrophages (M1) which stimulate inflammation, and alternatively activated macrophages (M2), which show anti-inflammatory activity. Therefore it is hypothesised that S. frutescens can potentially regulate macrophage polarization states which, in turn, influence metabolic immunomodulatory processes. The aims of this study were firstly to identify the mechanisms(s) by which S. frutescens could improve the low-grade inflammatory status in obese and T2D individuals using a transgenic mouse model of obesity, and secondly to determine the immunomodulating properties of S. frutescens in the human monocytic THP-1 cell line. Groups of nine week old male db/db mice were gavaged daily with water (vehicle control), Vildagliptin (10mL kg-1)(positive medication control) or hot aqueous S. frutescens extract at concentrations of 5mg, 50mg, 250mg kg-1 for 4 weeks. Body weight and fasting plasma glucose levels were determined weekly. The potential for hot aqueous S. frutescens extract to lower postprandial hyperglycaemia and promote insulin sensitivity was determined by an oral glucose tolerance test (OGTT) after a 16 hour fast, and an insulin radioimmunoassay (RIA) after a 4 hour fast before termination. After 4 weeks of hot aqueous S. frutescens treatment the total percentage body weight of 13 week old db/db mice was reduced, but hyperglycaemia was not prevented. Human THP-1 monocytes were stimulated to differentiate into macrophages with phorbol-12myristate-13acetate (PMA) and cultured under pro-inflammatory conditions (M1) or anti-inflammatory conditions (M2). Cell viability and anti-proliferative effects of LPS and S. frutescens extracts were determined. The effect of hot aqueous and ethanolic S. frutescens extracts on M1 and M2 macrophage cell surface markers was investigated by flow cytometry using CD86 (M1) and CD206 (M2). The effect of the S. frutescens extracts on three signalling pathways and a pro-inflammatory mediator activated in an LPS-induced inflammatory response were determined using Western blotting. Changes in mRNA gene expression levels of downstream transcription factors, cytokines and chemokines associated with M1 and M2 polarised macrophages were investigated using qRT-PCR. Both ethanolic and hot aqueous S. frutescens extracts reduced cytotoxicity caused by LPS. S. frutescens extracts alone did not alter cell viability. Furthermore, both hot and ethanolic S. frutescens extracts reduced expression of the M1 marker CD86 and nonsignificantly induced expression of an M2 marker CD206, following LPS stimulation. Following M2 induction, the M1 and M2 cell surface markers were reverted to baseline M0 macrophage expression by both S. frutescens extracts. The S. frutescens extracts mediated immune-regulatory activity through suppression of the pro-inflammatory p38 MAPK and NFκB signalling pathways and regulated apoptosis through the ERK1/2 pathway. The hot aqueous S. frutescens extract exerted anti-inflammatory effects through the IKK pathway and/ or GSK3β signalling pathway. This thesis demonstrates that S. frutescens promotes macrophage homeostasis by maintaining the balance between M1 and M2 macrophages during pro-and antiinflammatory immune responses. The regulation may occur during the activation and polarization process, via rapid deactivation of M1 macrophages and a decrease in need for macrophages to switch to an M2 phenotype. Furthermore S. frutescens is hypothesised to play a role in the regulation of the GSK3β signalling which plays a central role in regulating inflammation associated with pathophysiological conditions such as IR, T2D and obesity via the PI3K/Akt pathway.
- Full Text:
- Date Issued: 2019
A multi-threading software countermeasure to mitigate side channel analysis in the time domain
- Authors: Frieslaar, Ibraheem
- Date: 2019
- Subjects: Computer security , Data encryption (Computer science) , Noise generators (Electronics)
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/71152 , vital:29790
- Description: This research is the first of its kind to investigate the utilisation of a multi-threading software-based countermeasure to mitigate Side Channel Analysis (SCA) attacks, with a particular focus on the AES-128 cryptographic algorithm. This investigation is novel, as there has not been a software-based countermeasure relying on multi-threading to our knowledge. The research has been tested on the Atmel microcontrollers, as well as a more fully featured system in the form of the popular Raspberry Pi that utilises the ARM7 processor. The main contributions of this research is the introduction of a multi-threading software based countermeasure used to mitigate SCA attacks on both an embedded device and a Raspberry Pi. These threads are comprised of various mathematical operations which are utilised to generate electromagnetic (EM) noise resulting in the obfuscation of the execution of the AES-128 algorithm. A novel EM noise generator known as the FRIES noise generator is implemented to obfuscate data captured in the EM field. FRIES comprises of hiding the execution of AES-128 algorithm within the EM noise generated by the 512 Secure Hash Algorithm (SHA) from the libcrypto++ and OpenSSL libraries. In order to evaluate the proposed countermeasure, a novel attack methodology was developed where the entire secret AES-128 encryption key was recovered from a Raspberry Pi, which has not been achieved before. The FRIES noise generator was pitted against this new attack vector and other known noise generators. The results exhibited that the FRIES noise generator withstood this attack whilst other existing techniques still leaked out secret information. The visual location of the AES-128 encryption algorithm in the EM spectrum and key recovery was prevented. These results demonstrated that the proposed multi-threading software based countermeasure was able to be resistant to existing and new forms of attacks, thus verifying that a multi-threading software based countermeasure can serve to mitigate SCA attacks.
- Full Text:
- Date Issued: 2019
- Authors: Frieslaar, Ibraheem
- Date: 2019
- Subjects: Computer security , Data encryption (Computer science) , Noise generators (Electronics)
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/71152 , vital:29790
- Description: This research is the first of its kind to investigate the utilisation of a multi-threading software-based countermeasure to mitigate Side Channel Analysis (SCA) attacks, with a particular focus on the AES-128 cryptographic algorithm. This investigation is novel, as there has not been a software-based countermeasure relying on multi-threading to our knowledge. The research has been tested on the Atmel microcontrollers, as well as a more fully featured system in the form of the popular Raspberry Pi that utilises the ARM7 processor. The main contributions of this research is the introduction of a multi-threading software based countermeasure used to mitigate SCA attacks on both an embedded device and a Raspberry Pi. These threads are comprised of various mathematical operations which are utilised to generate electromagnetic (EM) noise resulting in the obfuscation of the execution of the AES-128 algorithm. A novel EM noise generator known as the FRIES noise generator is implemented to obfuscate data captured in the EM field. FRIES comprises of hiding the execution of AES-128 algorithm within the EM noise generated by the 512 Secure Hash Algorithm (SHA) from the libcrypto++ and OpenSSL libraries. In order to evaluate the proposed countermeasure, a novel attack methodology was developed where the entire secret AES-128 encryption key was recovered from a Raspberry Pi, which has not been achieved before. The FRIES noise generator was pitted against this new attack vector and other known noise generators. The results exhibited that the FRIES noise generator withstood this attack whilst other existing techniques still leaked out secret information. The visual location of the AES-128 encryption algorithm in the EM spectrum and key recovery was prevented. These results demonstrated that the proposed multi-threading software based countermeasure was able to be resistant to existing and new forms of attacks, thus verifying that a multi-threading software based countermeasure can serve to mitigate SCA attacks.
- Full Text:
- Date Issued: 2019
Incidence of cholera-causing and non cholera-causing pathogenic vibrio species in the river-k and two of its feeder wastewater treatment plants in the Raymond Mhlaba municipality, Eastern Cape province of South Africa
- Authors: Gcilitshana, Onele
- Date: 2019
- Subjects: Water -- Purification -- South Africa -- Eastern Cape Effluent quality -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/15145 , vital:40190
- Description: Despite technological advances in water treatment and improved sanitation in many developing countries, acute microbial diseases still thrive and continue to distress millions of people. This is due to the high number of rural dwellers that still source water for drinking and other domestic uses from contaminated rivers. In South Africa, there have been reports on waterborne disease outbreaks, and specifically in the area understudy, two records of diarrhoeal outbreaks associated with consumption of river water were reported within the last decade. All those outbreaks and previous reports on isolation of other pathogenic bacteria within the area necessitated the conduction of this study in order to identify the potential causes of the cholera-associate diarrheal outbreaks previously reported in the area and nationally. This study was designed to assess the incidence of cholera-causing and non-cholera causing pathogens in final effluents and surface waters of the Raymond Mhlaba Local Municipality, Eastern Cape Province, South Africa. RiverK which serves as a major resource for domestic activities, agricultural practices as well as an abstraction point for a potable water treatment plant was used for this study. River-K freshwater and final effluents of its two feeder wastewater treatment plants were sampled monthly, over a twelve-month period (December 2016–November 2017). For purposes of confidentiality, the names of the wastewater treatment plants and river involved are coded in this report. A total of 108 water samples were assessed for the physicochemical parameters that influence the presence of Vibrio pathogens. For bacteriology, the membrane filtration method followed by polymerase chain reaction (PCR) was adopted to assess the incidence of cholera-causing and non-choleracausing Vibrio pathogens, as well as their virulence-associated genes from the two wastewater treatment plants and their receiving waterbody (River-K). Antibiotic susceptibility profiles of identified Vibrio species were determined using the disc diffusion method against a panel of xvi sixteen antibiotics commonly used as antimicrobial drugs of Vibrio infections. Multiple antibiotics resistance index (MARI) and phenotypes (MARP) were measured, and the existence of antibiotic resistance genes was evaluated by PCR using specific primer sets. Most of the physicochemical parameters measured (pH, TDS, temperature, salinity and DO) complied with the recommended standards for drinking water, while some fell short of the recommended limits (EC, turbidity, TSS, free chlorine). From the presumptive Vibrio isolates, 64.3% (476/740) were confirmed by PCR, with their Vibrio densities across all sampling points ranging between 0 and 2.7 × 104 CFU/100 mL, with high counts recorded in summer, hence their positive significant correlation (P< 0.01) with temperature. From the confirmed Vibrio isolates, only V. cholerae (53/476), V. mimicus (21/476) and V. parahaemolyticus (5/476) were detected. For virulence-associated genes, virulence genes homologous to V. cholerae virulence determinants, namely ompU (35%), TCP (14%), ACE (11%), ctx (7%) and HylA (4.5%) were widespread (independently) amongst the V. cholerae and V. mimicus species, while V. parahemolyticus isolates (100%) produced only the ToxR gene. Antibiogram profiling found resistance against some antibiotics such as Nalidixic acid (65%), Polymyxin B (43.8%) etc. The MAR indices ranged between 0 and 0.67 with 41.3% of the isolates recording MAR index values above 0.2. The results presented high degrees of MARPs ranging from four to eleven antimicrobials. For resistance gene detection, the SXT element was detected in 66% of the isolates, while cat1 (93%) was the most predominant, followed by aac (68%), ant (61%), with bla-V (7.1%) as the least detected gene. Findings from this study suggest that the wastewater effluents from the two wastewater treatment plants are potential sources of pathogenic Vibrio species and River-K contains a high quantity of pathogenic Vibrio species with fluctuating seasonal variations that reaffirm temperature as a strong reason for their abundance. The antibiotic-resistant Vibrio species isolated here carry a pool of virulence-associated genes and xvii antibiotic resistance genes, presenting a health threat to the communities that use it directly for domestic and irrigation purposes. In conclusion, some surface waters in the Eastern Cape Province, South Africa are widely contaminated with cholera-causing and non-cholera causing Vibrio pathogens; furthermore, some wastewater treatment plants are ineffective in adequately removing microbial contaminants and have become sources of pathogenic bacteria to their receiving waterbodie
- Full Text:
- Date Issued: 2019
- Authors: Gcilitshana, Onele
- Date: 2019
- Subjects: Water -- Purification -- South Africa -- Eastern Cape Effluent quality -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/15145 , vital:40190
- Description: Despite technological advances in water treatment and improved sanitation in many developing countries, acute microbial diseases still thrive and continue to distress millions of people. This is due to the high number of rural dwellers that still source water for drinking and other domestic uses from contaminated rivers. In South Africa, there have been reports on waterborne disease outbreaks, and specifically in the area understudy, two records of diarrhoeal outbreaks associated with consumption of river water were reported within the last decade. All those outbreaks and previous reports on isolation of other pathogenic bacteria within the area necessitated the conduction of this study in order to identify the potential causes of the cholera-associate diarrheal outbreaks previously reported in the area and nationally. This study was designed to assess the incidence of cholera-causing and non-cholera causing pathogens in final effluents and surface waters of the Raymond Mhlaba Local Municipality, Eastern Cape Province, South Africa. RiverK which serves as a major resource for domestic activities, agricultural practices as well as an abstraction point for a potable water treatment plant was used for this study. River-K freshwater and final effluents of its two feeder wastewater treatment plants were sampled monthly, over a twelve-month period (December 2016–November 2017). For purposes of confidentiality, the names of the wastewater treatment plants and river involved are coded in this report. A total of 108 water samples were assessed for the physicochemical parameters that influence the presence of Vibrio pathogens. For bacteriology, the membrane filtration method followed by polymerase chain reaction (PCR) was adopted to assess the incidence of cholera-causing and non-choleracausing Vibrio pathogens, as well as their virulence-associated genes from the two wastewater treatment plants and their receiving waterbody (River-K). Antibiotic susceptibility profiles of identified Vibrio species were determined using the disc diffusion method against a panel of xvi sixteen antibiotics commonly used as antimicrobial drugs of Vibrio infections. Multiple antibiotics resistance index (MARI) and phenotypes (MARP) were measured, and the existence of antibiotic resistance genes was evaluated by PCR using specific primer sets. Most of the physicochemical parameters measured (pH, TDS, temperature, salinity and DO) complied with the recommended standards for drinking water, while some fell short of the recommended limits (EC, turbidity, TSS, free chlorine). From the presumptive Vibrio isolates, 64.3% (476/740) were confirmed by PCR, with their Vibrio densities across all sampling points ranging between 0 and 2.7 × 104 CFU/100 mL, with high counts recorded in summer, hence their positive significant correlation (P< 0.01) with temperature. From the confirmed Vibrio isolates, only V. cholerae (53/476), V. mimicus (21/476) and V. parahaemolyticus (5/476) were detected. For virulence-associated genes, virulence genes homologous to V. cholerae virulence determinants, namely ompU (35%), TCP (14%), ACE (11%), ctx (7%) and HylA (4.5%) were widespread (independently) amongst the V. cholerae and V. mimicus species, while V. parahemolyticus isolates (100%) produced only the ToxR gene. Antibiogram profiling found resistance against some antibiotics such as Nalidixic acid (65%), Polymyxin B (43.8%) etc. The MAR indices ranged between 0 and 0.67 with 41.3% of the isolates recording MAR index values above 0.2. The results presented high degrees of MARPs ranging from four to eleven antimicrobials. For resistance gene detection, the SXT element was detected in 66% of the isolates, while cat1 (93%) was the most predominant, followed by aac (68%), ant (61%), with bla-V (7.1%) as the least detected gene. Findings from this study suggest that the wastewater effluents from the two wastewater treatment plants are potential sources of pathogenic Vibrio species and River-K contains a high quantity of pathogenic Vibrio species with fluctuating seasonal variations that reaffirm temperature as a strong reason for their abundance. The antibiotic-resistant Vibrio species isolated here carry a pool of virulence-associated genes and xvii antibiotic resistance genes, presenting a health threat to the communities that use it directly for domestic and irrigation purposes. In conclusion, some surface waters in the Eastern Cape Province, South Africa are widely contaminated with cholera-causing and non-cholera causing Vibrio pathogens; furthermore, some wastewater treatment plants are ineffective in adequately removing microbial contaminants and have become sources of pathogenic bacteria to their receiving waterbodie
- Full Text:
- Date Issued: 2019
Attachment styles, coping strategies, personal meaning, and mental health in nonclinical adults
- Authors: Gerber, Ora
- Date: 2019
- Subjects: Attachment behavior -- South Africa , Mental illness -- South Africa Psychology, Applied
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/30485 , vital:30950
- Description: Meaning in life can be attained through a variety of sources. A limited amount of research has investigated the association between attachment and personal meaning while no studies have investigated the association between attachment, personal meaning, and sources of meaning. The current study aimed to investigate the association between different attachment styles, personal meaning, and sources of meaning in order to develop a deeper understanding of their relationships. A quantitative exploratory-descriptive design was used to collect the data using standardized questionnaires from 226 participants. Statistical analysis of the data suggests that a secure attachment style is positively associated with personal meaning and presented with meaning sources consisting of breadth and depth. A fearful attachment style was associated with a lack of personal meaning and sources of meaning while a preoccupied attachment style was associated with a lack of personal meaning and presented with sources of meaning lacking in depth and breadth. No significant association was found between a dismissive attachment style and personal meaning, but associations were found with sources of meaning, including feeling financially secure, experiencing personal growth, meeting basic everyday needs, and leaving a legacy for the next generation. Recommendations for psychotherapy based on the findings of the study were offered.
- Full Text:
- Date Issued: 2019
- Authors: Gerber, Ora
- Date: 2019
- Subjects: Attachment behavior -- South Africa , Mental illness -- South Africa Psychology, Applied
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/30485 , vital:30950
- Description: Meaning in life can be attained through a variety of sources. A limited amount of research has investigated the association between attachment and personal meaning while no studies have investigated the association between attachment, personal meaning, and sources of meaning. The current study aimed to investigate the association between different attachment styles, personal meaning, and sources of meaning in order to develop a deeper understanding of their relationships. A quantitative exploratory-descriptive design was used to collect the data using standardized questionnaires from 226 participants. Statistical analysis of the data suggests that a secure attachment style is positively associated with personal meaning and presented with meaning sources consisting of breadth and depth. A fearful attachment style was associated with a lack of personal meaning and sources of meaning while a preoccupied attachment style was associated with a lack of personal meaning and presented with sources of meaning lacking in depth and breadth. No significant association was found between a dismissive attachment style and personal meaning, but associations were found with sources of meaning, including feeling financially secure, experiencing personal growth, meeting basic everyday needs, and leaving a legacy for the next generation. Recommendations for psychotherapy based on the findings of the study were offered.
- Full Text:
- Date Issued: 2019
A strategic HRM framework for improving corporate governance in a municipal environment
- Gomomo, Jongisizwe Augustine
- Authors: Gomomo, Jongisizwe Augustine
- Date: 2019
- Subjects: Corporate governance -- South Africa , Personnel management Personnel departments
- Language: English
- Type: Thesis , Doctoral , DTech
- Identifier: http://hdl.handle.net/10948/39698 , vital:35349
- Description: In South Africa, the concept of corporate governance in a municipal environment is relatively new and the application of corporate governance principles remains a challenge (Ard and Berg, 2010, pp. 80-82). Previous research on corporate governance in a municipal environment mainly focused on challenges with regards to corporate governance and not on the role of strategic Human Resource Management in improving corporate governance. The main purpose of this study was therefore to develop a SHRM framework that could be utilised by municipalities to improve corporate governance. The following actions were taken to achieve this objective: A literature study was conducted to examine theory related to corporate governance and to consider corporate governance from an international, African and local government perspective. Various approaches, principles and practices related to corporate governance were also examined. The literature study further explored the legislative frameworks introduced in South Africa to improve corporate governance and in this respect the contribution of the Constitution of South Africa, the King Reports I-IV, Batho-Pele principles, municipal structures, municipal integrated development plans and the South African Board for People Practice are outlined. Existing SHRM models were analysed and specific HR strategies for improving corporate governance in municipalities were extracted from these models. The findings from the literature review were then integrated into a best practice SHRM framework for establishing corporate governance at municipalities. This integrated SHRM framework was used as a basis for the development of a survey questionnaire administered to employees in leadership positions at selected Eastern Cape metropolitan and district municipalities and the Eastern Cape Department of Co-operative Governance and Traditional Affairs. The questionnaire incorporated seven main HR strategies, indicators of corporate governance and corporate governance challenges at municipalities. The empirical results from this study revealed that HR Risk Management and Performance Management strategies were the main predictors of corporate governance at municipalities. Combining the HR strategies into a summative factor also demonstrated that HR strategies should be vertically aligned with the overall vision and mission of municipalities (effective and efficient service delivery) and horizontally integrated for optimal impact on corporate governance. Challenges experienced at municipalities did not moderate the relationship between the summative HR strategies and corporate governance. As such, these challenges cannot be justification for poor corporate governance at municipalities. The study makes a valuable theoretical and empirical contribution to the field of corporate governance, HRM and specifically corporate governance in a municipal environment. The integrated SHRM framework developed in the study is comprehensive and tested. Furthermore, the framework provides a specific context for corporate governance in a municipal environment by incorporating the legal Regulatory and Statutory framework for corporate governance, the SABPP Code of Conduct for HR practitioners, and the seven main SHRM focus areas, namely HR vision and strategy, employment practices, on-boarding practices, human capital development practices, Performance Management, designing and establishing an ethical organisation and HR Risk Management. In addition, it provides a link between these strategies and corporate governance indicators that is deemed important in a municipal environment where effective and efficient service delivery is the ultimate test for success.
- Full Text:
- Date Issued: 2019
- Authors: Gomomo, Jongisizwe Augustine
- Date: 2019
- Subjects: Corporate governance -- South Africa , Personnel management Personnel departments
- Language: English
- Type: Thesis , Doctoral , DTech
- Identifier: http://hdl.handle.net/10948/39698 , vital:35349
- Description: In South Africa, the concept of corporate governance in a municipal environment is relatively new and the application of corporate governance principles remains a challenge (Ard and Berg, 2010, pp. 80-82). Previous research on corporate governance in a municipal environment mainly focused on challenges with regards to corporate governance and not on the role of strategic Human Resource Management in improving corporate governance. The main purpose of this study was therefore to develop a SHRM framework that could be utilised by municipalities to improve corporate governance. The following actions were taken to achieve this objective: A literature study was conducted to examine theory related to corporate governance and to consider corporate governance from an international, African and local government perspective. Various approaches, principles and practices related to corporate governance were also examined. The literature study further explored the legislative frameworks introduced in South Africa to improve corporate governance and in this respect the contribution of the Constitution of South Africa, the King Reports I-IV, Batho-Pele principles, municipal structures, municipal integrated development plans and the South African Board for People Practice are outlined. Existing SHRM models were analysed and specific HR strategies for improving corporate governance in municipalities were extracted from these models. The findings from the literature review were then integrated into a best practice SHRM framework for establishing corporate governance at municipalities. This integrated SHRM framework was used as a basis for the development of a survey questionnaire administered to employees in leadership positions at selected Eastern Cape metropolitan and district municipalities and the Eastern Cape Department of Co-operative Governance and Traditional Affairs. The questionnaire incorporated seven main HR strategies, indicators of corporate governance and corporate governance challenges at municipalities. The empirical results from this study revealed that HR Risk Management and Performance Management strategies were the main predictors of corporate governance at municipalities. Combining the HR strategies into a summative factor also demonstrated that HR strategies should be vertically aligned with the overall vision and mission of municipalities (effective and efficient service delivery) and horizontally integrated for optimal impact on corporate governance. Challenges experienced at municipalities did not moderate the relationship between the summative HR strategies and corporate governance. As such, these challenges cannot be justification for poor corporate governance at municipalities. The study makes a valuable theoretical and empirical contribution to the field of corporate governance, HRM and specifically corporate governance in a municipal environment. The integrated SHRM framework developed in the study is comprehensive and tested. Furthermore, the framework provides a specific context for corporate governance in a municipal environment by incorporating the legal Regulatory and Statutory framework for corporate governance, the SABPP Code of Conduct for HR practitioners, and the seven main SHRM focus areas, namely HR vision and strategy, employment practices, on-boarding practices, human capital development practices, Performance Management, designing and establishing an ethical organisation and HR Risk Management. In addition, it provides a link between these strategies and corporate governance indicators that is deemed important in a municipal environment where effective and efficient service delivery is the ultimate test for success.
- Full Text:
- Date Issued: 2019
Teachers’ beliefs and classroom practices about their oral and written corrective feedback strategies in selected peri-urban and rural schools in Umguza district in Zimbabwe.
- Authors: Green , Flosie Florence
- Date: 2019
- Subjects: Teachers Classroom management
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/17987 , vital:42001
- Description: The goal of the study was to examine teachers’ beliefs and classroom practices about their corrective feedback strategies in selected peri-urban rural schools in Umguza District in Zimbabwe, in order to draw up a Corrective Feedback model aimed at enhancing ESL proficiency among O’ level school pupils. The study has been necessitated by challenges which post O’ level students face when communicating in English at institutions of higher learning. The study used the mixed research approach, whereby both quantitative and qualitative methods of gathering data were used though the dominant approach was the qualitative approach. Data was collected through questionnaires, semi structured interviews, lesson observations and examination of pupils’ written exercises. The questionnaire was completed by twenty two teachers. Semi-structured interviews were held with six teachers from the selected schools, while nine lesson observations were done and eighty exercise books were scrutinized for the presence of written Corrective Feedback. Results obtained showed that teachers’ stated beliefs about corrective feedback were not always demonstrated in their classroom practices. Furthermore the study revealed that oral Corrective Feedback was not used consistently in addition to a lack of uniformity in both the usage and interpretation of written Corrective Feedback. Results obtained showed that teachers’ stated beliefs about Corrective Feedback were not always demonstrated in their classroom practices. In addition, the study also revealed that some teachers were not aware of the codes used in written Corrective Feedback and their meaning. The conclusion reached in this study was that vi there is need for a more informed and consistent usage of Corrective Feedback among teachers. In the light of this finding, a Corrective Feedback model was suggested to assist teachers apply Corrective Feedback more consistently and more productively. A number of recommendations were made at the conclusion of this study. Firstly, it was recommended that marking codes be availed to teachers and pupils before the beginning of the school calendar. The contents of the advisory chart included in this study could be given to pupils to copy onto the back of their exercise books to enable them to interpret the feedback which the teachers would have written. It was recommended that teachers familiarise themselves with the developments in the use of CF in the ESL classroom. At school level this could be done through staff development workshop, where teachers share experiences about what works and what does not work in the ESL classroom. This should be done in view of the existing problem of communicative incompetency bedevilling pupils nationally. Secondly it was recommended that teachers familiarise themselves with the developments in the use of CF in the ESL classroom. The final recommendation was that teachers adopt minimal marking in the form of codes in order to cut down on turnaround time as well as stimulate individual learner automatisation of knowledge.
- Full Text:
- Date Issued: 2019
- Authors: Green , Flosie Florence
- Date: 2019
- Subjects: Teachers Classroom management
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/17987 , vital:42001
- Description: The goal of the study was to examine teachers’ beliefs and classroom practices about their corrective feedback strategies in selected peri-urban rural schools in Umguza District in Zimbabwe, in order to draw up a Corrective Feedback model aimed at enhancing ESL proficiency among O’ level school pupils. The study has been necessitated by challenges which post O’ level students face when communicating in English at institutions of higher learning. The study used the mixed research approach, whereby both quantitative and qualitative methods of gathering data were used though the dominant approach was the qualitative approach. Data was collected through questionnaires, semi structured interviews, lesson observations and examination of pupils’ written exercises. The questionnaire was completed by twenty two teachers. Semi-structured interviews were held with six teachers from the selected schools, while nine lesson observations were done and eighty exercise books were scrutinized for the presence of written Corrective Feedback. Results obtained showed that teachers’ stated beliefs about corrective feedback were not always demonstrated in their classroom practices. Furthermore the study revealed that oral Corrective Feedback was not used consistently in addition to a lack of uniformity in both the usage and interpretation of written Corrective Feedback. Results obtained showed that teachers’ stated beliefs about Corrective Feedback were not always demonstrated in their classroom practices. In addition, the study also revealed that some teachers were not aware of the codes used in written Corrective Feedback and their meaning. The conclusion reached in this study was that vi there is need for a more informed and consistent usage of Corrective Feedback among teachers. In the light of this finding, a Corrective Feedback model was suggested to assist teachers apply Corrective Feedback more consistently and more productively. A number of recommendations were made at the conclusion of this study. Firstly, it was recommended that marking codes be availed to teachers and pupils before the beginning of the school calendar. The contents of the advisory chart included in this study could be given to pupils to copy onto the back of their exercise books to enable them to interpret the feedback which the teachers would have written. It was recommended that teachers familiarise themselves with the developments in the use of CF in the ESL classroom. At school level this could be done through staff development workshop, where teachers share experiences about what works and what does not work in the ESL classroom. This should be done in view of the existing problem of communicative incompetency bedevilling pupils nationally. Secondly it was recommended that teachers familiarise themselves with the developments in the use of CF in the ESL classroom. The final recommendation was that teachers adopt minimal marking in the form of codes in order to cut down on turnaround time as well as stimulate individual learner automatisation of knowledge.
- Full Text:
- Date Issued: 2019
The synthesis and assessment of thioxanthone- and xanthone- derived compounds as hosts for application in host-guest chemistry
- Authors: Greyling, Lizé
- Date: 2019
- Subjects: Chemistry, Organic , Biochemistry
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/42525 , vital:36665
- Description: In this work, the host capabilities of two structurally related compounds, N,N’-bis(9-phenyl-9- thioxanthenyl)ethylenediamine (H1) and N,N’-bis(9-phenyl-9-xanthenyl)ethylenediamine (H2) were compared in the presence of a wide variety of guest species. Additionally, the selectivity displayed by these host compounds were examined when exposed to mixtures of guests in order to ascertain whether it would be feasible to employ them in alternative separation strategies for the purification of industrially relevant chemicals. H1 and H2 were synthesized by reacting thioxanthone and xanthone with phenylmagnesium bromide. The resultant alcohol was then treated with perchloric acid and, finally, two of these molecules were effectively linked by utilizing ethylenediamine to afford the two host compounds. Initially, H1 and H2 were investigated for their inclusion abilities by recrystallizing each from a number of potential isomeric and non-isomeric guest compounds such as the xylenes and ethylbenzene, methylanisoles and anisole, methylpyridines and pyridine, methylcyclohexanones and cyclohexanone, heterocyclic five- and six- membered ring compounds, alkylsubstituted benzenes, anilines, and dihaloalkanes. H1 displayed excellent inclusion ability when presented with the above-mentioned compounds, and a 1:1 H:G ratio was consistently preferred in each case. H2 also proved to be successful in this regard but did not include the methylcyclohexanones and cyclohexanone nor the heterocyclic five-membered ring solvents. Furthermore, varying host:guest ratios were observed for the complexes formed with H2. Mixed competition experiments were carried out in the presence of either isomeric or related but non-isomeric guest species. When H1 and H2 were independently recrystallized from mixtures of the former, selectivity orders correlated for both hosts, but it was observed that H2 exhibited an enhanced selectivity for the preferred guests in each case, compared with H1. Interestingly, in mixtures of the latter, host behaviours were distinctly opposing (with the exception of the dihaloalkanes). H1, and even more so H2, demonstrated very high selectivities for p-xylene, aniline and N,Ndimethylaniline from the xylene and aniline guest series, respectively, where selectivities were found to be ~90% or higher for host recrystallization experiments from respective mixtures of these guests. Single crystal X-ray diffraction, Hirshfeld surface and thermal analyses were employed in order to elucidate the reasons for any selectivity observations. The inclusion of these guests was, in most cases, found to be as a result of interactions between host and guest species, which included π∙∙∙π stacking, C‒H∙∙∙π, hydrogen bonding and various other short contact types. Guest compounds were accommodated in either cavities or channels and this was dependent on the nature of the guest. The host molecule conformations showed H1 to adopt a bent tricyclic fused ring system with the N atoms of the linker in a synclinal arrangement, while in complexes with H2, the fused ring system was near-planar and the N atoms adopted an antiperiplanar geometry. These key differences resulted in a very ordered host‒host packing for H2 as a direct result of the more planar O-containing ring and linear linker; for H1, on the other hand, the buckled S-containing ring and gauche-orientated N atoms resulted in a less ordered packing, which ultimately related to the differences in the behaviour of the two host species. Hirshfeld surface analyses, in general, did not provide much information to explain the host selectivities, with the exception of complexes containing the five-membered ring guest heterocyclics. Thermal analyses were completed on all suitable host-guest complexes and, in most cases but not all, the onset and peak temperatures (terms Ton and Tp, respectively) were related to the thermal stability of the complexes, which were used to rationalize the selectivities of these host compounds.
- Full Text:
- Date Issued: 2019
- Authors: Greyling, Lizé
- Date: 2019
- Subjects: Chemistry, Organic , Biochemistry
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/42525 , vital:36665
- Description: In this work, the host capabilities of two structurally related compounds, N,N’-bis(9-phenyl-9- thioxanthenyl)ethylenediamine (H1) and N,N’-bis(9-phenyl-9-xanthenyl)ethylenediamine (H2) were compared in the presence of a wide variety of guest species. Additionally, the selectivity displayed by these host compounds were examined when exposed to mixtures of guests in order to ascertain whether it would be feasible to employ them in alternative separation strategies for the purification of industrially relevant chemicals. H1 and H2 were synthesized by reacting thioxanthone and xanthone with phenylmagnesium bromide. The resultant alcohol was then treated with perchloric acid and, finally, two of these molecules were effectively linked by utilizing ethylenediamine to afford the two host compounds. Initially, H1 and H2 were investigated for their inclusion abilities by recrystallizing each from a number of potential isomeric and non-isomeric guest compounds such as the xylenes and ethylbenzene, methylanisoles and anisole, methylpyridines and pyridine, methylcyclohexanones and cyclohexanone, heterocyclic five- and six- membered ring compounds, alkylsubstituted benzenes, anilines, and dihaloalkanes. H1 displayed excellent inclusion ability when presented with the above-mentioned compounds, and a 1:1 H:G ratio was consistently preferred in each case. H2 also proved to be successful in this regard but did not include the methylcyclohexanones and cyclohexanone nor the heterocyclic five-membered ring solvents. Furthermore, varying host:guest ratios were observed for the complexes formed with H2. Mixed competition experiments were carried out in the presence of either isomeric or related but non-isomeric guest species. When H1 and H2 were independently recrystallized from mixtures of the former, selectivity orders correlated for both hosts, but it was observed that H2 exhibited an enhanced selectivity for the preferred guests in each case, compared with H1. Interestingly, in mixtures of the latter, host behaviours were distinctly opposing (with the exception of the dihaloalkanes). H1, and even more so H2, demonstrated very high selectivities for p-xylene, aniline and N,Ndimethylaniline from the xylene and aniline guest series, respectively, where selectivities were found to be ~90% or higher for host recrystallization experiments from respective mixtures of these guests. Single crystal X-ray diffraction, Hirshfeld surface and thermal analyses were employed in order to elucidate the reasons for any selectivity observations. The inclusion of these guests was, in most cases, found to be as a result of interactions between host and guest species, which included π∙∙∙π stacking, C‒H∙∙∙π, hydrogen bonding and various other short contact types. Guest compounds were accommodated in either cavities or channels and this was dependent on the nature of the guest. The host molecule conformations showed H1 to adopt a bent tricyclic fused ring system with the N atoms of the linker in a synclinal arrangement, while in complexes with H2, the fused ring system was near-planar and the N atoms adopted an antiperiplanar geometry. These key differences resulted in a very ordered host‒host packing for H2 as a direct result of the more planar O-containing ring and linear linker; for H1, on the other hand, the buckled S-containing ring and gauche-orientated N atoms resulted in a less ordered packing, which ultimately related to the differences in the behaviour of the two host species. Hirshfeld surface analyses, in general, did not provide much information to explain the host selectivities, with the exception of complexes containing the five-membered ring guest heterocyclics. Thermal analyses were completed on all suitable host-guest complexes and, in most cases but not all, the onset and peak temperatures (terms Ton and Tp, respectively) were related to the thermal stability of the complexes, which were used to rationalize the selectivities of these host compounds.
- Full Text:
- Date Issued: 2019
Livestock water productivity: towards improving rural livelihoods from livestock in semi-arid rangelands
- Authors: Gusha, Bukho
- Date: 2019
- Subjects: Livestock -- South Africa -- Eastern Cape , Livestock -- Effect of drought on -- South Africa -- Eastern Cape , Animals -- Food -- South Africa -- Eastern Cape , Livestock -- Effect of water quality on -- South Africa -- Eastern Cape , Livestock -- Water requirements -- South Africa -- Eastern Cape , Livestock productivity -- South Africa -- Eastern Cape , Stochastic analysis , Communal rangelands -- South Africa -- Eastern Cape , Land degradation -- South Africa -- Eastern Cape , Animal owners -- South Africa -- Eastern Cape , Livestock improvement -- South Africa -- Eastern Cape
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/115171 , vital:34084
- Description: Communal rangelands in South Africa mainly occur in the former homelands. The former homelands constitute 13% of the land surface area and support a quarter of the country's human population with a wide range of goods and services, among them, grazing for livestock, mostly reared on communal rangelands. These rangelands are degraded and cannot sustain maximum livestock production because of poor species composition and low standing biomass, however research has been conducted on livestock production at household level (where all livestock goods and services are valued). This provides an opportunity to conduct a study describing livestock water productivity in the north of the Eastern Cape, where livestock production is a primary source of livelihood for rural communities from which many households generate cash but where different practices and factors undermine high livestock production. Many studies have focused on understanding the water productivity of a natural rangeland system for commercially oriented crop-livestock systems, but the aim of this study is to contribute towards improving rural livelihoods from livestock in the sub-humid rangelands of the north Eastern Cape. Here, unimproved native grasslands are the major source of feed for livestock and people do not have herders to take livestock to the most productive parts of the rangelands. Households were surveyed using a questionnaire on livestock household contribution, socioeconomic characteristics of the household, livestock holdings and livestock production strategies. Rangeland productivity was measured in the field. Experimental animals for livestock grazing distribution were identified and fitted with Global Positioning Systems (GPS) collars to identify the seasonal grazing areas. These activities shed light on the biophysical attributes of the ecosystem and livestock production in a communal rangeland system. Because continuous grazing in the rangelands of the north Eastern Cape reduces the standing biomass, there is no obvious aboveground biomass to provide a visual perspective of production nor is it possible to determine production without excluding the livestock. Thus, four parallel lines of evidence were employed to measure rangeland productivity: line intercept, grazing exclosures, net photosynthesis from earth observation and disc pasture meter. Earth observation products were used to derive the amount of water used by the landscape to produce this forage (i.e. evapotranspiration or ET) and these measurements of net primary production and landscape water use were used in preparing a value of livestock water productivity (LWP) for this farming system. There has been the perception that residents of the study area lack knowledge of technical efficiencies in the large stock sector at household level. The study used stochastic frontier analysis to assess livestock production and followed with a household survey to collect information on socio-economic characteristics and information on livestock practices. The data from the household survey were used to estimate the technical efficiency of households using a stochastic frontier analysis. Productivity and inefficiency variables that increase livestock production or increase technical difficulties were identified. The focus on livestock has mostly been on the direct value of livestock to owners with a poor understanding of their value to non-livestock owners, where cultural activities, such as livestock slaughtering, were documented as the only source of protein for non-livestock owners. However, the value that is available to non-livestock owners has not been quantified. This study assessed livestockbased livelihoods of communal people to improve their livelihoods through a household survey looking at the contribution of livestock to both livestock and non-livestock owners. Earlier work on LWP has focused on systems where animals were on ‘fed, cut and carry’ and irrigated systems. However, there is a need to describe LWP in a natural grazing system and this study set out to achieve this for these communal rangelands through a household survey that determined the value of livestock goods and services given the amount of water used (ET). Lastly, livestock grazing distribution across the landscape was assessed, using GPS collars that recorded livestock behaviour every five minutes during the daylight. This approach was necessary because livestock grazing patterns in these communal rangelands is poorly controlled by people, and animals are largely free-ranging, grazing selectively, based on their own preferences, which leads to localised overgrazing. This part of the study was achieved through experimental livestock collaring and weighing (both sheep and goats) for the wet and dry seasons. The collared livestock were weighed on the day of putting on collars and the day of removing the collars. The results on livestock grazing distribution were analysed using the R package, T-LoCoH. The major finding of this study was that communal rangelands of the north Eastern Cape can improve rural livelihoods from livestock if proper interventions for both livestock and rangeland production and productivity can be implemented. One of these interventions is fencing as it was found that exclosures that were fenced during the study yielded high aboveground productivity comparable to that achieved in commercial rangelands, yielding 220 g DM m-2 yr-1. Surveys using the calibrated disc pasture meter showed the need for proper rotation and resting of the rangeland. Net photosynthesis of 880.7 g C m-2 yr-1 for unimproved grassland in good condition was comparable to commercial rangelands in the region. Using the line intercept, vegetation cover was found to be a good predictor of aboveground standing biomass; thus a positive relationship was revealed. Lastly, annual ET of 270 mm yr-1 was calculated using the Penman Monteith Palmer (PMP) equation, while 379 mm yr-1 was extracted from the MOD16 product, suggesting that PMP ET may not be accurate in these grassland systems due to the slow response of MODIS Leaf Area Index (LAI). The average household technical efficiency (TE) score was found to be 0.79 on the study sites, indicating the potential for households to improve outputs from livestock. A range of household categories were identified, based on gender and an index of wealth, and households with lower and higher TE were identified. This analysis revealed that productivity variables such as holding higher livestock numbers and providing additional feed achieved high livestock outputs, suggesting high livestock productivity. However, in terms of inefficiency variables, gender (female-headed households), dwelling type (an index of homestead wealth), kraaling livestock at night and herding livestock during the day were found to improve technical efficiency. It was revealed in this study that households keep livestock to derive different goods and services including offtake, manure, milk, wool and services such as traction. The non-livestock owning households were reported to also benefit from the abovementioned goods and services in the study site and that the value of their contribution could be quantified, thus contributing significantly to rural livelihoods. The study showed that LWP was comparable with other studies such as those conducted in Ethiopia. This study compared its results with the studies conducted outside South Africa as there were limited comparable South African studies available; however, this does not necessarily mean we can use the same model as the value of livestock outputs varies based on the preferred outputs. This study developed an LWP model for the natural rangeland system. The LWP values were measured in ZAR and later converted in USD and were divided into three different categories based on the wealth index, such as better-off, middle wealth and poor households. Lastly, this study showed that livestock (both cattle and sheep) spend a high proportion of their grazing day, during both the wet and dry seasons, in a small physical area, immediately around the homesteads. These are areas where the active green growth occurs throughout the year, suggesting the need for livestock herders to move livestock around the landscape for more effective landscape use. Herding has the potential to improve landscape use and conserve grazing resource and the ability of a household to attain best outputs from livestock. Positive daily weight gains were reported in collared livestock during the wet season. However, both sheep and cattle lost weight during the dry season. This study recommends interventions such as labour for herding, and other animal husbandry-related activities including milking, handling, and vaccinating animals. Market opportunities for communal rangeland livestock should be facilitated by informing livestock owners about livestock market specifications to improve their livelihoods. Lastly, proper grazing management planning, such as fencing, which enables rotational grazing, and herding which moves animals to the most productive parts of the rangeland, should be implemented so that rangelands can be rested for plant growth, vigour, and improved aboveground net primary productivity. Based on the recommendations made in this study, a research development approach is necessary which prioritises female empowerment in agriculture and poor farmers as female-headed households were reported by this study to be more technically efficient.
- Full Text:
- Date Issued: 2019
- Authors: Gusha, Bukho
- Date: 2019
- Subjects: Livestock -- South Africa -- Eastern Cape , Livestock -- Effect of drought on -- South Africa -- Eastern Cape , Animals -- Food -- South Africa -- Eastern Cape , Livestock -- Effect of water quality on -- South Africa -- Eastern Cape , Livestock -- Water requirements -- South Africa -- Eastern Cape , Livestock productivity -- South Africa -- Eastern Cape , Stochastic analysis , Communal rangelands -- South Africa -- Eastern Cape , Land degradation -- South Africa -- Eastern Cape , Animal owners -- South Africa -- Eastern Cape , Livestock improvement -- South Africa -- Eastern Cape
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/115171 , vital:34084
- Description: Communal rangelands in South Africa mainly occur in the former homelands. The former homelands constitute 13% of the land surface area and support a quarter of the country's human population with a wide range of goods and services, among them, grazing for livestock, mostly reared on communal rangelands. These rangelands are degraded and cannot sustain maximum livestock production because of poor species composition and low standing biomass, however research has been conducted on livestock production at household level (where all livestock goods and services are valued). This provides an opportunity to conduct a study describing livestock water productivity in the north of the Eastern Cape, where livestock production is a primary source of livelihood for rural communities from which many households generate cash but where different practices and factors undermine high livestock production. Many studies have focused on understanding the water productivity of a natural rangeland system for commercially oriented crop-livestock systems, but the aim of this study is to contribute towards improving rural livelihoods from livestock in the sub-humid rangelands of the north Eastern Cape. Here, unimproved native grasslands are the major source of feed for livestock and people do not have herders to take livestock to the most productive parts of the rangelands. Households were surveyed using a questionnaire on livestock household contribution, socioeconomic characteristics of the household, livestock holdings and livestock production strategies. Rangeland productivity was measured in the field. Experimental animals for livestock grazing distribution were identified and fitted with Global Positioning Systems (GPS) collars to identify the seasonal grazing areas. These activities shed light on the biophysical attributes of the ecosystem and livestock production in a communal rangeland system. Because continuous grazing in the rangelands of the north Eastern Cape reduces the standing biomass, there is no obvious aboveground biomass to provide a visual perspective of production nor is it possible to determine production without excluding the livestock. Thus, four parallel lines of evidence were employed to measure rangeland productivity: line intercept, grazing exclosures, net photosynthesis from earth observation and disc pasture meter. Earth observation products were used to derive the amount of water used by the landscape to produce this forage (i.e. evapotranspiration or ET) and these measurements of net primary production and landscape water use were used in preparing a value of livestock water productivity (LWP) for this farming system. There has been the perception that residents of the study area lack knowledge of technical efficiencies in the large stock sector at household level. The study used stochastic frontier analysis to assess livestock production and followed with a household survey to collect information on socio-economic characteristics and information on livestock practices. The data from the household survey were used to estimate the technical efficiency of households using a stochastic frontier analysis. Productivity and inefficiency variables that increase livestock production or increase technical difficulties were identified. The focus on livestock has mostly been on the direct value of livestock to owners with a poor understanding of their value to non-livestock owners, where cultural activities, such as livestock slaughtering, were documented as the only source of protein for non-livestock owners. However, the value that is available to non-livestock owners has not been quantified. This study assessed livestockbased livelihoods of communal people to improve their livelihoods through a household survey looking at the contribution of livestock to both livestock and non-livestock owners. Earlier work on LWP has focused on systems where animals were on ‘fed, cut and carry’ and irrigated systems. However, there is a need to describe LWP in a natural grazing system and this study set out to achieve this for these communal rangelands through a household survey that determined the value of livestock goods and services given the amount of water used (ET). Lastly, livestock grazing distribution across the landscape was assessed, using GPS collars that recorded livestock behaviour every five minutes during the daylight. This approach was necessary because livestock grazing patterns in these communal rangelands is poorly controlled by people, and animals are largely free-ranging, grazing selectively, based on their own preferences, which leads to localised overgrazing. This part of the study was achieved through experimental livestock collaring and weighing (both sheep and goats) for the wet and dry seasons. The collared livestock were weighed on the day of putting on collars and the day of removing the collars. The results on livestock grazing distribution were analysed using the R package, T-LoCoH. The major finding of this study was that communal rangelands of the north Eastern Cape can improve rural livelihoods from livestock if proper interventions for both livestock and rangeland production and productivity can be implemented. One of these interventions is fencing as it was found that exclosures that were fenced during the study yielded high aboveground productivity comparable to that achieved in commercial rangelands, yielding 220 g DM m-2 yr-1. Surveys using the calibrated disc pasture meter showed the need for proper rotation and resting of the rangeland. Net photosynthesis of 880.7 g C m-2 yr-1 for unimproved grassland in good condition was comparable to commercial rangelands in the region. Using the line intercept, vegetation cover was found to be a good predictor of aboveground standing biomass; thus a positive relationship was revealed. Lastly, annual ET of 270 mm yr-1 was calculated using the Penman Monteith Palmer (PMP) equation, while 379 mm yr-1 was extracted from the MOD16 product, suggesting that PMP ET may not be accurate in these grassland systems due to the slow response of MODIS Leaf Area Index (LAI). The average household technical efficiency (TE) score was found to be 0.79 on the study sites, indicating the potential for households to improve outputs from livestock. A range of household categories were identified, based on gender and an index of wealth, and households with lower and higher TE were identified. This analysis revealed that productivity variables such as holding higher livestock numbers and providing additional feed achieved high livestock outputs, suggesting high livestock productivity. However, in terms of inefficiency variables, gender (female-headed households), dwelling type (an index of homestead wealth), kraaling livestock at night and herding livestock during the day were found to improve technical efficiency. It was revealed in this study that households keep livestock to derive different goods and services including offtake, manure, milk, wool and services such as traction. The non-livestock owning households were reported to also benefit from the abovementioned goods and services in the study site and that the value of their contribution could be quantified, thus contributing significantly to rural livelihoods. The study showed that LWP was comparable with other studies such as those conducted in Ethiopia. This study compared its results with the studies conducted outside South Africa as there were limited comparable South African studies available; however, this does not necessarily mean we can use the same model as the value of livestock outputs varies based on the preferred outputs. This study developed an LWP model for the natural rangeland system. The LWP values were measured in ZAR and later converted in USD and were divided into three different categories based on the wealth index, such as better-off, middle wealth and poor households. Lastly, this study showed that livestock (both cattle and sheep) spend a high proportion of their grazing day, during both the wet and dry seasons, in a small physical area, immediately around the homesteads. These are areas where the active green growth occurs throughout the year, suggesting the need for livestock herders to move livestock around the landscape for more effective landscape use. Herding has the potential to improve landscape use and conserve grazing resource and the ability of a household to attain best outputs from livestock. Positive daily weight gains were reported in collared livestock during the wet season. However, both sheep and cattle lost weight during the dry season. This study recommends interventions such as labour for herding, and other animal husbandry-related activities including milking, handling, and vaccinating animals. Market opportunities for communal rangeland livestock should be facilitated by informing livestock owners about livestock market specifications to improve their livelihoods. Lastly, proper grazing management planning, such as fencing, which enables rotational grazing, and herding which moves animals to the most productive parts of the rangeland, should be implemented so that rangelands can be rested for plant growth, vigour, and improved aboveground net primary productivity. Based on the recommendations made in this study, a research development approach is necessary which prioritises female empowerment in agriculture and poor farmers as female-headed households were reported by this study to be more technically efficient.
- Full Text:
- Date Issued: 2019
Reflection and representation: modes of communicating Zimbabwean historical narratives through popular music
- Authors: Gwindingwe, Gift
- Date: 2019
- Subjects: Communication Interpersonal communication
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/15804 , vital:40528
- Description: Music, before and after independence in the former colonies, has been playing a central role of articulating national concerns. It became an alternative medium through which historical narratives were channeled out to the public. While many scholars have acknowledged the critical role of music’s attempt to whip the autocratic governments into line, and the attempts by the governments across the world to thwart the critical/activism role of music, little emphasis was put on the mechanism of circumventing censorship, the linguistic competence (or lack of it) of music in conscientising the public on national issues. This thesis aims to harness this seemingly entertainment tool (music) into serious academic discourse by looking at the way power relations and ideological contestations are symbolically reflected, represented and communicated in popular culture, in particular the Zimbabwean Sungura and Chimurenga music. It makes a critical analysis of the diction of music as it attempts (or fails to) reflect and represent the Zimbabwean historical narratives from the early 1990s to 2008. The study tries to (semiologically) fracture the musical lexicon and the ideological stance on which it is based to show the extent to which music communicates by way of reflecting and representing the Zimbabwean historical narratives. The thesis looks at how popular music has ‘become the most prominent signifier’ and at ‘the shifting meanings and the significance of … music’ (Nooshin 2005:231) in Zimbabwe. It utilises a qualitative research approach specifically an interpretive prism. Key research methods for the study include in-depth semi-structured interviews which were conducted with purposively selected informants such as university academics and two of the selected musicians. The selected academics were purposively sampled basing on the researcher’s knowledge of their inclination towards Cultural Studies, particularly popular culture. The study has managed to bring clarity to the research questions in a big way considering the application of the various theories that framed the thesis discussion. Research findings indicate that interpretive semiotics aids to unpack the philosophy of meaning making through song. Music as a medium has the reflective effect of a mirror and a photographic effect of a camera to enunciate the ideological innuendo in the leader-led dichotomy. The study shows that protest popular music rejects knowledge that affirms the status quo; it is counter hegemonic and seeks to regenerate selfhoods and self-liberation amongst the subaltern class.
- Full Text:
- Date Issued: 2019
- Authors: Gwindingwe, Gift
- Date: 2019
- Subjects: Communication Interpersonal communication
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/15804 , vital:40528
- Description: Music, before and after independence in the former colonies, has been playing a central role of articulating national concerns. It became an alternative medium through which historical narratives were channeled out to the public. While many scholars have acknowledged the critical role of music’s attempt to whip the autocratic governments into line, and the attempts by the governments across the world to thwart the critical/activism role of music, little emphasis was put on the mechanism of circumventing censorship, the linguistic competence (or lack of it) of music in conscientising the public on national issues. This thesis aims to harness this seemingly entertainment tool (music) into serious academic discourse by looking at the way power relations and ideological contestations are symbolically reflected, represented and communicated in popular culture, in particular the Zimbabwean Sungura and Chimurenga music. It makes a critical analysis of the diction of music as it attempts (or fails to) reflect and represent the Zimbabwean historical narratives from the early 1990s to 2008. The study tries to (semiologically) fracture the musical lexicon and the ideological stance on which it is based to show the extent to which music communicates by way of reflecting and representing the Zimbabwean historical narratives. The thesis looks at how popular music has ‘become the most prominent signifier’ and at ‘the shifting meanings and the significance of … music’ (Nooshin 2005:231) in Zimbabwe. It utilises a qualitative research approach specifically an interpretive prism. Key research methods for the study include in-depth semi-structured interviews which were conducted with purposively selected informants such as university academics and two of the selected musicians. The selected academics were purposively sampled basing on the researcher’s knowledge of their inclination towards Cultural Studies, particularly popular culture. The study has managed to bring clarity to the research questions in a big way considering the application of the various theories that framed the thesis discussion. Research findings indicate that interpretive semiotics aids to unpack the philosophy of meaning making through song. Music as a medium has the reflective effect of a mirror and a photographic effect of a camera to enunciate the ideological innuendo in the leader-led dichotomy. The study shows that protest popular music rejects knowledge that affirms the status quo; it is counter hegemonic and seeks to regenerate selfhoods and self-liberation amongst the subaltern class.
- Full Text:
- Date Issued: 2019
Optimising construction project role-player performance
- Authors: Hefer, Andre Le Roux
- Date: 2019
- Subjects: Construction industry -- Management , Project management Performance
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/40316 , vital:36140
- Description: Authors predict major changes in the requirements to manage complex environments in the 21st century. These 21st century challenges, for Project Managers (PM) in the construction industry, are evident through the ongoing perception that the industry performance record is suboptimal. In the pursuit of performance optimisation, management disciplines developed and implemented theories and models not only to achieve what is required, but also to excel and create high-performing teams. In search of project success, researchers have also identified quantifiable variables, models, success factors and other related issues. The PM’s role in the attainment of success has also been widely researched, especially the impact, influence, methods and tools related to the discipline. Nevertheless, the general concern remains, that the performance of the industry is suboptimal. This study therefore aimed to qualitatively evaluate and examine the various factors and influences on performance of a construction project team. This research applies to the motivation and environmental factors influencing project teams in the achievement of optimum performance; and in doing so, to enhance the performance of project-role players; while adding disciplinespecific theory. This study has employed in-depth interview data, which were thematically analysed. The interviews were conducted in a case-study design comprising four projects in South Africa. The study concluded by emphasising the importance of how role-players RELATE to each other, and LOVE project challenges. It further noted that PMs who are MANAGING LEADERS would be most influential in the project environment; while PROCUREMENT greatly influences the project environment. Relational issues are important to role-players; and they act as MOTIVATORS, with certain issues in a project presenting both performance BARRIERS and DRIVER capabilities. Finally, project MOMENTUM changes constantly, with the current momentum direction influencing the future course thereof. In meeting the aims of the research, a Performance Optimisation Framework was developed, noting how the emergent themes co-exist in optimal performance environments. The study also developed the Project Husbandry approach, reflecting on a caring, nurturing, diligent and mature approach when managing role-players. The study recommends that the themes impacting the project-operating environment should be influenced by management and leadership, in order to optimise the performance of all the role-players involved.
- Full Text:
- Date Issued: 2019
- Authors: Hefer, Andre Le Roux
- Date: 2019
- Subjects: Construction industry -- Management , Project management Performance
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/40316 , vital:36140
- Description: Authors predict major changes in the requirements to manage complex environments in the 21st century. These 21st century challenges, for Project Managers (PM) in the construction industry, are evident through the ongoing perception that the industry performance record is suboptimal. In the pursuit of performance optimisation, management disciplines developed and implemented theories and models not only to achieve what is required, but also to excel and create high-performing teams. In search of project success, researchers have also identified quantifiable variables, models, success factors and other related issues. The PM’s role in the attainment of success has also been widely researched, especially the impact, influence, methods and tools related to the discipline. Nevertheless, the general concern remains, that the performance of the industry is suboptimal. This study therefore aimed to qualitatively evaluate and examine the various factors and influences on performance of a construction project team. This research applies to the motivation and environmental factors influencing project teams in the achievement of optimum performance; and in doing so, to enhance the performance of project-role players; while adding disciplinespecific theory. This study has employed in-depth interview data, which were thematically analysed. The interviews were conducted in a case-study design comprising four projects in South Africa. The study concluded by emphasising the importance of how role-players RELATE to each other, and LOVE project challenges. It further noted that PMs who are MANAGING LEADERS would be most influential in the project environment; while PROCUREMENT greatly influences the project environment. Relational issues are important to role-players; and they act as MOTIVATORS, with certain issues in a project presenting both performance BARRIERS and DRIVER capabilities. Finally, project MOMENTUM changes constantly, with the current momentum direction influencing the future course thereof. In meeting the aims of the research, a Performance Optimisation Framework was developed, noting how the emergent themes co-exist in optimal performance environments. The study also developed the Project Husbandry approach, reflecting on a caring, nurturing, diligent and mature approach when managing role-players. The study recommends that the themes impacting the project-operating environment should be influenced by management and leadership, in order to optimise the performance of all the role-players involved.
- Full Text:
- Date Issued: 2019
Bolvedere: a scalable network flow threat analysis system
- Authors: Herbert, Alan
- Date: 2019
- Subjects: Bolvedere (Computer network analysis system) , Computer networks -- Scalability , Computer networks -- Measurement , Computer networks -- Security measures , Telecommunication -- Traffic -- Measurement
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/71557 , vital:29873
- Description: Since the advent of the Internet, and its public availability in the late 90’s, there have been significant advancements to network technologies and thus a significant increase of the bandwidth available to network users, both human and automated. Although this growth is of great value to network users, it has led to an increase in malicious network-based activities and it is theorized that, as more services become available on the Internet, the volume of such activities will continue to grow. Because of this, there is a need to monitor, comprehend, discern, understand and (where needed) respond to events on networks worldwide. Although this line of thought is simple in its reasoning, undertaking such a task is no small feat. Full packet analysis is a method of network surveillance that seeks out specific characteristics within network traffic that may tell of malicious activity or anomalies in regular network usage. It is carried out within firewalls and implemented through packet classification. In the context of the networks that make up the Internet, this form of packet analysis has become infeasible, as the volume of traffic introduced onto these networks every day is so large that there are simply not enough processing resources to perform such a task on every packet in real time. One could combat this problem by performing post-incident forensics; archiving packets and processing them later. However, as one cannot process all incoming packets, the archive will eventually run out of space. Full packet analysis is also hindered by the fact that some existing, commonly-used solutions are designed around a single host and single thread of execution, an outdated approach that is far slower than necessary on current computing technology. This research explores the conceptual design and implementation of a scalable network traffic analysis system named Bolvedere. Analysis performed by Bolvedere simply asks whether the existence of a connection, coupled with its associated metadata, is enough to conclude something meaningful about that connection. This idea draws away from the traditional processing of every single byte in every single packet monitored on a network link (Deep Packet Inspection) through the concept of working with connection flows. Bolvedere performs its work by leveraging the NetFlow version 9 and IPFIX protocols, but is not limited to these. It is implemented using a modular approach that allows for either complete execution of the system on a single host or the horizontal scaling out of subsystems on multiple hosts. The use of multiple hosts is achieved through the implementation of Zero Message Queue (ZMQ). This allows for Bolvedre to horizontally scale out, which results in an increase in processing resources and thus an increase in analysis throughput. This is due to ease of interprocess communications provided by ZMQ. Many underlying mechanisms in Bolvedere have been automated. This is intended to make the system more userfriendly, as the user need only tell Bolvedere what information they wish to analyse, and the system will then rebuild itself in order to achieve this required task. Bolvedere has also been hardware-accelerated through the use of Field-Programmable Gate Array (FPGA) technologies, which more than doubled the total throughput of the system.
- Full Text:
- Date Issued: 2019
- Authors: Herbert, Alan
- Date: 2019
- Subjects: Bolvedere (Computer network analysis system) , Computer networks -- Scalability , Computer networks -- Measurement , Computer networks -- Security measures , Telecommunication -- Traffic -- Measurement
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/71557 , vital:29873
- Description: Since the advent of the Internet, and its public availability in the late 90’s, there have been significant advancements to network technologies and thus a significant increase of the bandwidth available to network users, both human and automated. Although this growth is of great value to network users, it has led to an increase in malicious network-based activities and it is theorized that, as more services become available on the Internet, the volume of such activities will continue to grow. Because of this, there is a need to monitor, comprehend, discern, understand and (where needed) respond to events on networks worldwide. Although this line of thought is simple in its reasoning, undertaking such a task is no small feat. Full packet analysis is a method of network surveillance that seeks out specific characteristics within network traffic that may tell of malicious activity or anomalies in regular network usage. It is carried out within firewalls and implemented through packet classification. In the context of the networks that make up the Internet, this form of packet analysis has become infeasible, as the volume of traffic introduced onto these networks every day is so large that there are simply not enough processing resources to perform such a task on every packet in real time. One could combat this problem by performing post-incident forensics; archiving packets and processing them later. However, as one cannot process all incoming packets, the archive will eventually run out of space. Full packet analysis is also hindered by the fact that some existing, commonly-used solutions are designed around a single host and single thread of execution, an outdated approach that is far slower than necessary on current computing technology. This research explores the conceptual design and implementation of a scalable network traffic analysis system named Bolvedere. Analysis performed by Bolvedere simply asks whether the existence of a connection, coupled with its associated metadata, is enough to conclude something meaningful about that connection. This idea draws away from the traditional processing of every single byte in every single packet monitored on a network link (Deep Packet Inspection) through the concept of working with connection flows. Bolvedere performs its work by leveraging the NetFlow version 9 and IPFIX protocols, but is not limited to these. It is implemented using a modular approach that allows for either complete execution of the system on a single host or the horizontal scaling out of subsystems on multiple hosts. The use of multiple hosts is achieved through the implementation of Zero Message Queue (ZMQ). This allows for Bolvedre to horizontally scale out, which results in an increase in processing resources and thus an increase in analysis throughput. This is due to ease of interprocess communications provided by ZMQ. Many underlying mechanisms in Bolvedere have been automated. This is intended to make the system more userfriendly, as the user need only tell Bolvedere what information they wish to analyse, and the system will then rebuild itself in order to achieve this required task. Bolvedere has also been hardware-accelerated through the use of Field-Programmable Gate Array (FPGA) technologies, which more than doubled the total throughput of the system.
- Full Text:
- Date Issued: 2019