A case for ethical frameworks to enhance mobile government implementation at South African municipalities
- Makwembere, Sandra, Garidzira, Rufaro
- Authors: Makwembere, Sandra , Garidzira, Rufaro
- Date: 2021
- Subjects: Government Ethics Technology and state Article
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/11260/7170 , vital:53081 , xlink:href="https://doi.org/10.4102/td.v17i1.826"
- Description: Interest in mobile government (m-government) is growing globally. Mobile government refers to the use of wireless and mobile technologies to deliver services to citizens, businesses, employees and other government entities. Presently, technological advancements take place despite questions on whether the existing policy and regulatory frameworks are suitable to regulate the effects of m-government. With m-government, municipal operations take place in virtual spaces where the consequences of such operations are still largely unknown and the frameworks that are apt to minimise any long-term effects on society are yet to be defined. This conceptual article suggests that ethical frameworks should be encouraged as part of mobile government implementation in municipalities to encourage reflective municipal practices and to improve judgement and behaviour in m-government decision-making. It contributes to debates on approaches to comprehensively support and guide mobile government towards positive municipal service delivery outcomes. Keywords: m-government; ethics; ethical frameworks; municipal service delivery; e-government; mobile technology
- Full Text:
- Date Issued: 2021
- Authors: Makwembere, Sandra , Garidzira, Rufaro
- Date: 2021
- Subjects: Government Ethics Technology and state Article
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/11260/7170 , vital:53081 , xlink:href="https://doi.org/10.4102/td.v17i1.826"
- Description: Interest in mobile government (m-government) is growing globally. Mobile government refers to the use of wireless and mobile technologies to deliver services to citizens, businesses, employees and other government entities. Presently, technological advancements take place despite questions on whether the existing policy and regulatory frameworks are suitable to regulate the effects of m-government. With m-government, municipal operations take place in virtual spaces where the consequences of such operations are still largely unknown and the frameworks that are apt to minimise any long-term effects on society are yet to be defined. This conceptual article suggests that ethical frameworks should be encouraged as part of mobile government implementation in municipalities to encourage reflective municipal practices and to improve judgement and behaviour in m-government decision-making. It contributes to debates on approaches to comprehensively support and guide mobile government towards positive municipal service delivery outcomes. Keywords: m-government; ethics; ethical frameworks; municipal service delivery; e-government; mobile technology
- Full Text:
- Date Issued: 2021
A critical assessment of the relationship between the AfCFTA and World Trade Organisation dispute settlement mechanisms, in light of the Conflict of Jurisdiction
- Nhemachena, Tichakunda Charles
- Authors: Nhemachena, Tichakunda Charles
- Date: 2021-10-29
- Subjects: African Continental Free Trade Area , World Trade Organization , Dispute resolution (Law) , Conflict of judicial decisions , Good faith (Law)
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/192052 , vital:45191
- Description: This thesis interrogates the relationship between the Dispute Settlement Understanding and Africa Continental Free Trade Area dispute settlement mechanism, in light of the conflict of jurisdiction. The conflict of jurisdiction is an adverse effect of the fragmentation of international law. The uncoordinated proliferation of international treaties has increased occurrences of overlapping memberships and overlapping subject matter regulation amongst treaties. Whenever the overlaps mentioned above exist, and a dispute arises concerning matters of overlap, that dispute can be heard in more than one tribunal, giving rise to a conflict of jurisdiction. Jurisdictional conflicts are a problem because they breed uncertainty in the adjudication of disputes; they increase the risk of forum shopping, conflict of rulings, protracted litigation, and waste resources. There is a significant risk for jurisdictional conflicts between the World Trade Organisation and Africa Continental Free Trade Area agreements, because of membership and subject matter overlaps. To mitigate the problems caused by jurisdictional conflicts, the Africa Continental Free Trade Area agreement has incorporated a fork-in-the-road clause. Fork-in-the-road provisions allow parties to choose their preferred forum, and once the forum is chosen, the parties are prohibited from bringing the same dispute to another tribunal. Unfortunately, fork-in-the-road clauses are insufficient in resolving jurisdictional conflicts because they do not bind the Dispute Settlement Understanding. It is only bound to enforce World Trade Organisation obligations and not non-World Trade Organisation obligations. The extent to which non-World Trade Organisation norms apply in the Dispute Settlement Understanding is unsettled, making it difficult to conclude whether a fork-in-the-road provision will be effective an effective solution to potential jurisdictional conflicts. In this thesis, the researcher investigates the prospects of the World Trade Organisation applying the AfCFTA fork-in-the-road clause, directly, as a potential solution to the conflict of jurisdiction. In addition, the researcher will also investigate an alternative means of applying the AfCFTA fork-in-the-road provision, indirectly, using the World Trade Organisation procedural good faith provisions. In conclusion, the researcher provides recommendations on how the World Trade Organisation and the AfCFTA agreement can facilitate the application of fork-in-the-road clauses in the Dispute Settlement Understanding to resolve the conflict of jurisdiction. , Thesis (LLM) -- Faculty of Law, Law, 2021
- Full Text:
- Date Issued: 2021-10-29
- Authors: Nhemachena, Tichakunda Charles
- Date: 2021-10-29
- Subjects: African Continental Free Trade Area , World Trade Organization , Dispute resolution (Law) , Conflict of judicial decisions , Good faith (Law)
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/192052 , vital:45191
- Description: This thesis interrogates the relationship between the Dispute Settlement Understanding and Africa Continental Free Trade Area dispute settlement mechanism, in light of the conflict of jurisdiction. The conflict of jurisdiction is an adverse effect of the fragmentation of international law. The uncoordinated proliferation of international treaties has increased occurrences of overlapping memberships and overlapping subject matter regulation amongst treaties. Whenever the overlaps mentioned above exist, and a dispute arises concerning matters of overlap, that dispute can be heard in more than one tribunal, giving rise to a conflict of jurisdiction. Jurisdictional conflicts are a problem because they breed uncertainty in the adjudication of disputes; they increase the risk of forum shopping, conflict of rulings, protracted litigation, and waste resources. There is a significant risk for jurisdictional conflicts between the World Trade Organisation and Africa Continental Free Trade Area agreements, because of membership and subject matter overlaps. To mitigate the problems caused by jurisdictional conflicts, the Africa Continental Free Trade Area agreement has incorporated a fork-in-the-road clause. Fork-in-the-road provisions allow parties to choose their preferred forum, and once the forum is chosen, the parties are prohibited from bringing the same dispute to another tribunal. Unfortunately, fork-in-the-road clauses are insufficient in resolving jurisdictional conflicts because they do not bind the Dispute Settlement Understanding. It is only bound to enforce World Trade Organisation obligations and not non-World Trade Organisation obligations. The extent to which non-World Trade Organisation norms apply in the Dispute Settlement Understanding is unsettled, making it difficult to conclude whether a fork-in-the-road provision will be effective an effective solution to potential jurisdictional conflicts. In this thesis, the researcher investigates the prospects of the World Trade Organisation applying the AfCFTA fork-in-the-road clause, directly, as a potential solution to the conflict of jurisdiction. In addition, the researcher will also investigate an alternative means of applying the AfCFTA fork-in-the-road provision, indirectly, using the World Trade Organisation procedural good faith provisions. In conclusion, the researcher provides recommendations on how the World Trade Organisation and the AfCFTA agreement can facilitate the application of fork-in-the-road clauses in the Dispute Settlement Understanding to resolve the conflict of jurisdiction. , Thesis (LLM) -- Faculty of Law, Law, 2021
- Full Text:
- Date Issued: 2021-10-29
A modelling approach to the analysis of complex survey data
- Authors: Dlangamandla, Olwethu
- Date: 2021-10-29
- Subjects: Sampling (Statistics) , Linear models (Statistics) , Multilevel models (Statistics) , Logistic regression analysis , Complex survey data
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/192955 , vital:45284
- Description: Surveys are an essential tool for collecting data and most surveys use complex sampling designs to collect the data. Complex sampling designs are used mainly to enhance representativeness in the sample by accounting for the underlying structure of the population. This often results in data that are non-independent and clustered. Ignoring complex design features such as clustering, stratification, multistage and unequal probability sampling may result in inaccurate and incorrect inference. An overview of, and difference between, design-based and model-based approaches to inference for complex survey data has been discussed. This study adopts a model-based approach. The objective of this study is to discuss and describe the modelling approach in analysing complex survey data. This is specifically done by introducing the principle inference methods under which data from complex surveys may be analysed. In particular, discussions on the theory and methods of model fitting for the analysis of complex survey data are presented. We begin by discussing unique features of complex survey data and explore appropriate methods of analysis that account for the complexity inherent in the survey data. We also explore the widely applied logistic regression modelling of binary data in a complex sample survey context. In particular, four forms of logistic regression models are fitted. These models are generalized linear models, multilevel models, mixed effects models and generalized linear mixed models. Simulated complex survey data are used to illustrate the methods and models. Various R packages are used for the analysis. The results presented and discussed in this thesis indicate that a logistic mixed model with first and second level predictors has a better fit compared to a logistic mixed model with first level predictors. In addition, a logistic multilevel model with first and second level predictors and nested random effects provides a better fit to the data compared to other logistic multilevel fitted models. Similar results were obtained from fitting a generalized logistic mixed model with first and second level predictor variables and a generalized linear mixed model with first and second level predictors and nested random effects. , Thesis (MSC) -- Faculty of Science, Statistics, 2021
- Full Text:
- Date Issued: 2021-10-29
- Authors: Dlangamandla, Olwethu
- Date: 2021-10-29
- Subjects: Sampling (Statistics) , Linear models (Statistics) , Multilevel models (Statistics) , Logistic regression analysis , Complex survey data
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/192955 , vital:45284
- Description: Surveys are an essential tool for collecting data and most surveys use complex sampling designs to collect the data. Complex sampling designs are used mainly to enhance representativeness in the sample by accounting for the underlying structure of the population. This often results in data that are non-independent and clustered. Ignoring complex design features such as clustering, stratification, multistage and unequal probability sampling may result in inaccurate and incorrect inference. An overview of, and difference between, design-based and model-based approaches to inference for complex survey data has been discussed. This study adopts a model-based approach. The objective of this study is to discuss and describe the modelling approach in analysing complex survey data. This is specifically done by introducing the principle inference methods under which data from complex surveys may be analysed. In particular, discussions on the theory and methods of model fitting for the analysis of complex survey data are presented. We begin by discussing unique features of complex survey data and explore appropriate methods of analysis that account for the complexity inherent in the survey data. We also explore the widely applied logistic regression modelling of binary data in a complex sample survey context. In particular, four forms of logistic regression models are fitted. These models are generalized linear models, multilevel models, mixed effects models and generalized linear mixed models. Simulated complex survey data are used to illustrate the methods and models. Various R packages are used for the analysis. The results presented and discussed in this thesis indicate that a logistic mixed model with first and second level predictors has a better fit compared to a logistic mixed model with first level predictors. In addition, a logistic multilevel model with first and second level predictors and nested random effects provides a better fit to the data compared to other logistic multilevel fitted models. Similar results were obtained from fitting a generalized logistic mixed model with first and second level predictor variables and a generalized linear mixed model with first and second level predictors and nested random effects. , Thesis (MSC) -- Faculty of Science, Statistics, 2021
- Full Text:
- Date Issued: 2021-10-29
A multiple case study exploration into community members’ ecopsychological responses to environmental degradation in South Africa
- Authors: Barnwell, Garret
- Date: 2021-03
- Subjects: Environmental psychology -- South Africa , Environmental degradation -- South Africa
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/54892 , vital:48377
- Description: The psychological impact of environmental degradation in South Africa and its impact on communities’ relationships to the natural world is an understudied area. This study’s main aim was to explore community members’ reactions and responses to different forms of environmental degradation in South Africa by analysing two case studies: Rustenburg in the North West province and Limpopo province’s Vhembe District. The qualitative case studies relied on emplaced individual and focus group interviews. The findings from this study are presented in this doctoral thesis by publication. The first case study of Rustenburg in the North West’s platinum mining belt was selected due to the extractive industry’s historical impact on the natural environment, which is interlinked with the identity and heritage of host mining communities who could be considered land and environmental defenders. Two publications have been published on this case study. The first article, Critical reflections from South Africa: Using the Power Threat Meaning Framework to place climate-related distress in its socio-political context, was published in the British Psychology Society’s Clinical Psychology Forum Special Issue: Psychology and the Climate and Environmental Crisis in August 2020 and provides a critical reflection on psychological distress in Rustenburg, and questions whether popular terms used, such as “climate anxieties”, are useful for communities confronted by ecological crises. The paper concludes that there is danger in the dehistoricisation and medicalisation of distress that is rooted in climate, land and environmental injustices. The paper sets the scene for papers to follow that examine the interrelationship between place attachments and psychological responses to environmental degradation associated with slow violence. The second article, ’Nothing green can grow without being on the land’: Mine-affected communities’ psychological experiences of ecological degradation and resistance in Rustenburg, South Africa, was published in Community Psychology in Global Perspective Special Issue: Communities reclaiming power and social justice in the face of climate change and presents a broad overview of psychological responses to ecological degradation associated with environmental injustices. The paper suggests that psychological distress is attributed to environmental injustices. Furthermore, the process of place severing – the psychological threats, harms and disruptions to place-based dialogues – contributes to distress experienced in extractive settings. The two articles in this case study concluded by demonstrating how community resistance plays a part in addressing cumulative ecological harms and restoring the ancestral relationship with place. The second case study in the Vhembe District was selected due to the community’s psycho-spiritual connection to the sacred sites in the area and the histories of environmental degradation in the area. Article three, ‘Mupo is life’: Intergenerational community identity and safeguarding of sacred natural sites is in press in the journal Ecopsychology. The paper found that place plays a role in shaping and transferring intergenerational community identities. Furthermore, Zwifho shape worldviews about Mupo, i.e. all of existence, that underpin land and environmental defenders’ responses to environmental degradation and place severing. The fourth article, “Restoring roots”: Lived experiences of place severing and dialogical resurgence associated with deforestation and land dispossession in Limpopo province, South Africa, is under review by AWRY: Journal of Critical Psychology. The article demonstrates that place severing is rooted in histories of colonialism and that distress is related to losses and cumulative ecological harm. Furthermore, the article shows how decolonial dialogical resurgence responds to the mechanisms that drive place severing. The fifth and final publication, Grounding community psychology in ecopsychosocial accompaniment, is a chapter that explores opportunities for community psychologists to accompany others, specifically in relationship with people who have experienced displacement and environmental justice struggles. Collectively, these four articles and book chapter present the first publications of a larger research study that spans two South African case studies and that should yield several more publications. These publications draw on critical psychologies, including decolonial theory, liberation psychology, critical community psychology and radical ecopsychology. Within this thesis, the journal articles and book chapter are consolidated by an overarching discussion chapter that situates these five publications within the context of existing literature, and describes how existing theory and methodology have been advanced. The study demonstrates the interconnectedness between histories of colonialism, land injustices and environmental degradation that contribute to intergenerational psychological distress. Grassroots community organising groups play a critical role in addressing the resulting cumulative environmental harms through place-based resistance and dialogical resurgence. Moreover, the study suggests that critical psychologies have important roles to play in supporting land and environmental justice struggles through critical research, evaluations and assessments, and litigation. , Thesis (PhD) -- Faculty of Business and Economic Sciences, 2021
- Full Text:
- Date Issued: 2021-03
- Authors: Barnwell, Garret
- Date: 2021-03
- Subjects: Environmental psychology -- South Africa , Environmental degradation -- South Africa
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10948/54892 , vital:48377
- Description: The psychological impact of environmental degradation in South Africa and its impact on communities’ relationships to the natural world is an understudied area. This study’s main aim was to explore community members’ reactions and responses to different forms of environmental degradation in South Africa by analysing two case studies: Rustenburg in the North West province and Limpopo province’s Vhembe District. The qualitative case studies relied on emplaced individual and focus group interviews. The findings from this study are presented in this doctoral thesis by publication. The first case study of Rustenburg in the North West’s platinum mining belt was selected due to the extractive industry’s historical impact on the natural environment, which is interlinked with the identity and heritage of host mining communities who could be considered land and environmental defenders. Two publications have been published on this case study. The first article, Critical reflections from South Africa: Using the Power Threat Meaning Framework to place climate-related distress in its socio-political context, was published in the British Psychology Society’s Clinical Psychology Forum Special Issue: Psychology and the Climate and Environmental Crisis in August 2020 and provides a critical reflection on psychological distress in Rustenburg, and questions whether popular terms used, such as “climate anxieties”, are useful for communities confronted by ecological crises. The paper concludes that there is danger in the dehistoricisation and medicalisation of distress that is rooted in climate, land and environmental injustices. The paper sets the scene for papers to follow that examine the interrelationship between place attachments and psychological responses to environmental degradation associated with slow violence. The second article, ’Nothing green can grow without being on the land’: Mine-affected communities’ psychological experiences of ecological degradation and resistance in Rustenburg, South Africa, was published in Community Psychology in Global Perspective Special Issue: Communities reclaiming power and social justice in the face of climate change and presents a broad overview of psychological responses to ecological degradation associated with environmental injustices. The paper suggests that psychological distress is attributed to environmental injustices. Furthermore, the process of place severing – the psychological threats, harms and disruptions to place-based dialogues – contributes to distress experienced in extractive settings. The two articles in this case study concluded by demonstrating how community resistance plays a part in addressing cumulative ecological harms and restoring the ancestral relationship with place. The second case study in the Vhembe District was selected due to the community’s psycho-spiritual connection to the sacred sites in the area and the histories of environmental degradation in the area. Article three, ‘Mupo is life’: Intergenerational community identity and safeguarding of sacred natural sites is in press in the journal Ecopsychology. The paper found that place plays a role in shaping and transferring intergenerational community identities. Furthermore, Zwifho shape worldviews about Mupo, i.e. all of existence, that underpin land and environmental defenders’ responses to environmental degradation and place severing. The fourth article, “Restoring roots”: Lived experiences of place severing and dialogical resurgence associated with deforestation and land dispossession in Limpopo province, South Africa, is under review by AWRY: Journal of Critical Psychology. The article demonstrates that place severing is rooted in histories of colonialism and that distress is related to losses and cumulative ecological harm. Furthermore, the article shows how decolonial dialogical resurgence responds to the mechanisms that drive place severing. The fifth and final publication, Grounding community psychology in ecopsychosocial accompaniment, is a chapter that explores opportunities for community psychologists to accompany others, specifically in relationship with people who have experienced displacement and environmental justice struggles. Collectively, these four articles and book chapter present the first publications of a larger research study that spans two South African case studies and that should yield several more publications. These publications draw on critical psychologies, including decolonial theory, liberation psychology, critical community psychology and radical ecopsychology. Within this thesis, the journal articles and book chapter are consolidated by an overarching discussion chapter that situates these five publications within the context of existing literature, and describes how existing theory and methodology have been advanced. The study demonstrates the interconnectedness between histories of colonialism, land injustices and environmental degradation that contribute to intergenerational psychological distress. Grassroots community organising groups play a critical role in addressing the resulting cumulative environmental harms through place-based resistance and dialogical resurgence. Moreover, the study suggests that critical psychologies have important roles to play in supporting land and environmental justice struggles through critical research, evaluations and assessments, and litigation. , Thesis (PhD) -- Faculty of Business and Economic Sciences, 2021
- Full Text:
- Date Issued: 2021-03
A self-emulsifying delivery system loaded with efavirenz: The case for flax-seed oil
- Authors: Mazonde, Priveledge
- Date: 2021-10-29
- Subjects: Drug delivery systems , Linseed oil , Antiretroviral agents , HIV (Viruses) , Drug carriers (Pharmacy) , Solubility , High performance liquid chromatography , Efavirenz
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/192944 , vital:45283
- Description: The feasibility of incorporating efavirenz (EFV), an antiretroviral agent against HIV into a lipid-based self-emulsifying drug delivery system (SEDDS) containing vegetable oils was investigated. EFV has poor aqueous solubility and is classified under the Biopharmaceutical Classification System (BCS) as a class II compound with highly permeability, its aqueous solubility is less than 10 mg/ml and is defined as a practically insoluble compound with a consequent poor bioavailability of approximately 40%, and erratic dissolution behaviour. SEDDS formulations have been shown to improve the aqueous solubility and consequently the bioavailability of BCS II compounds such as EFV. EFV is a first line antiviral agent used in combination with other agents in antiretroviral therapy (ART). Among the number of NNRTIs approved for use in HIV treatment, EFV is one of the most commonly prescribed drug. Statistical methods and Design of Experiments (DoE) using Response Surface Methodology (RSM), specifically a Central Composite Design (CCD), were used to facilitate the development of a reversed-phase high performance liquid chromatographic (HPLC) method for the quantitation of EFV during formulation product and process development studies. A rapid, accurate, precise and sensitive HPLC method with ultraviolet (UV) detection was developed, optimised and validated for the in-vitro analysis of EFV in a total run time under 10 minutes for the elution of both EFV and loratidine which was used as the internal standard (IS). The method was then successfully applied to the determination of EFV in commercially available tablets. Excipient screening was undertaken using solubility studies and revealed that EFV had highest solubility in flaxseed oil in comparison to soybean, macadamia, grapeseed, sunflower and olive oils. The non-ionic Tween® 80 and Span® 20 were selected as surfactant and co-surfactant, respectively with ethanol co-solvent as they exhibited improved miscibility with co-solvent. Pre-formulation studies were undertaken to investigate the compatibility of the API with excipients and to identify a nano-emulsion region and other emulsion types using pseudoternary phase diagrams. The phase behaviour of crude cold pressed flaxseed oil with the selected non-ionic surfactants revealed an area within pseudo-ternary phase diagrams for different surfactant-mixtures formed gels/semisolid structures which can be exploited for other drug delivery strategies that require such properties. Fourier transform infrared spectroscopy (FT-IR), powder x-ray diffraction (XRD) and Raman spectroscopy were used to identify and assess the compatibility of EFV with chosen excipients. 2 A reduction in the peak intensity was observed for EFV when combined with each hydrophobic/lipid excipient evaluated revealing that there was a marked reduction in the crystallinity of the EFV. A decrease in crystallinity in comparison with the bulk API may indicate that EFV were amorphous or sequestered in a molecular dispersion and exhibited an increased solubility for the molecule. Flaxseed oil was used as the oil phase in studies for the optimization of surfactant mixtures undertaken using DoE, specifically a D-optimal mixtures design with the flaxseed oil content set at 10% m/m was performed. Solutions from the desired optimization function were produced based on desirability and five nanoemulsion formulations were produced and characterized in terms of in vitro release of efavirenz, drug loading capacity, Zeta Potential, droplet sizes and polydispersity index (PDI). Kinetically stable nanoemulsions containing 10% m/m flaxseed oil were successfully manufactured and assessed. Droplet sizes ranged between 156 and 225 nm, Zeta Potential between −24 and −41 mV and all formulations were found to be monodisperse with polydispersity indices ≤ 0.487. SEDDS formulations of EFV in nano-sized carriers were developed and optimised, in vitro drug release varied with varying amounts of ethanol in the formulation producing formulations that exhibited differently modulated drug in-vitro release profiles that may be further manipulated for better performance and therapeutic outcomes in terms of solubility and possibly bioavailability of EFV when delivered using SEDDS rather than using tablets which in turn may lead to better therapeutic outcomes for patients with HIV. , Thesis (MSc) -- Faculty of Pharmacy, Pharmacy, 2021
- Full Text:
- Date Issued: 2021-10-29
- Authors: Mazonde, Priveledge
- Date: 2021-10-29
- Subjects: Drug delivery systems , Linseed oil , Antiretroviral agents , HIV (Viruses) , Drug carriers (Pharmacy) , Solubility , High performance liquid chromatography , Efavirenz
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/192944 , vital:45283
- Description: The feasibility of incorporating efavirenz (EFV), an antiretroviral agent against HIV into a lipid-based self-emulsifying drug delivery system (SEDDS) containing vegetable oils was investigated. EFV has poor aqueous solubility and is classified under the Biopharmaceutical Classification System (BCS) as a class II compound with highly permeability, its aqueous solubility is less than 10 mg/ml and is defined as a practically insoluble compound with a consequent poor bioavailability of approximately 40%, and erratic dissolution behaviour. SEDDS formulations have been shown to improve the aqueous solubility and consequently the bioavailability of BCS II compounds such as EFV. EFV is a first line antiviral agent used in combination with other agents in antiretroviral therapy (ART). Among the number of NNRTIs approved for use in HIV treatment, EFV is one of the most commonly prescribed drug. Statistical methods and Design of Experiments (DoE) using Response Surface Methodology (RSM), specifically a Central Composite Design (CCD), were used to facilitate the development of a reversed-phase high performance liquid chromatographic (HPLC) method for the quantitation of EFV during formulation product and process development studies. A rapid, accurate, precise and sensitive HPLC method with ultraviolet (UV) detection was developed, optimised and validated for the in-vitro analysis of EFV in a total run time under 10 minutes for the elution of both EFV and loratidine which was used as the internal standard (IS). The method was then successfully applied to the determination of EFV in commercially available tablets. Excipient screening was undertaken using solubility studies and revealed that EFV had highest solubility in flaxseed oil in comparison to soybean, macadamia, grapeseed, sunflower and olive oils. The non-ionic Tween® 80 and Span® 20 were selected as surfactant and co-surfactant, respectively with ethanol co-solvent as they exhibited improved miscibility with co-solvent. Pre-formulation studies were undertaken to investigate the compatibility of the API with excipients and to identify a nano-emulsion region and other emulsion types using pseudoternary phase diagrams. The phase behaviour of crude cold pressed flaxseed oil with the selected non-ionic surfactants revealed an area within pseudo-ternary phase diagrams for different surfactant-mixtures formed gels/semisolid structures which can be exploited for other drug delivery strategies that require such properties. Fourier transform infrared spectroscopy (FT-IR), powder x-ray diffraction (XRD) and Raman spectroscopy were used to identify and assess the compatibility of EFV with chosen excipients. 2 A reduction in the peak intensity was observed for EFV when combined with each hydrophobic/lipid excipient evaluated revealing that there was a marked reduction in the crystallinity of the EFV. A decrease in crystallinity in comparison with the bulk API may indicate that EFV were amorphous or sequestered in a molecular dispersion and exhibited an increased solubility for the molecule. Flaxseed oil was used as the oil phase in studies for the optimization of surfactant mixtures undertaken using DoE, specifically a D-optimal mixtures design with the flaxseed oil content set at 10% m/m was performed. Solutions from the desired optimization function were produced based on desirability and five nanoemulsion formulations were produced and characterized in terms of in vitro release of efavirenz, drug loading capacity, Zeta Potential, droplet sizes and polydispersity index (PDI). Kinetically stable nanoemulsions containing 10% m/m flaxseed oil were successfully manufactured and assessed. Droplet sizes ranged between 156 and 225 nm, Zeta Potential between −24 and −41 mV and all formulations were found to be monodisperse with polydispersity indices ≤ 0.487. SEDDS formulations of EFV in nano-sized carriers were developed and optimised, in vitro drug release varied with varying amounts of ethanol in the formulation producing formulations that exhibited differently modulated drug in-vitro release profiles that may be further manipulated for better performance and therapeutic outcomes in terms of solubility and possibly bioavailability of EFV when delivered using SEDDS rather than using tablets which in turn may lead to better therapeutic outcomes for patients with HIV. , Thesis (MSc) -- Faculty of Pharmacy, Pharmacy, 2021
- Full Text:
- Date Issued: 2021-10-29
An analysis of citizen participation in service delivery in Zimbabwe’s small towns: A case study of Chiredzi Town Council
- Authors: Matsilele, Blessing
- Date: 2021-10-29
- Subjects: Municipal services Zimbabwe Chiredzi Rural District , Political participation Zimbabwe Chiredzi Rural District , Social capital (Sociology) Zimbabwe Chiredzi Rural District , Municipal services Zimbabwe Chiredzi Rural District Citizen participation , Community development Zimbabwe Chiredzi Rural District
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/190099 , vital:44963
- Description: Over the years, there have been complaints of poor service delivery in Zimbabwe’s Urban Councils. Newspapers in Zimbabwe have been filled with stories of poor service delivery and citizen grievances. Existing literature on service delivery has focused on the causes of poor service delivery, blaming them solely on the local government authorities. The literature has blamed poor service delivery in Zimbabwe on corruption, polarisation, politicisation, and incapacitation amongst other things. What is not highlighted is the role that citizens play and their responsibility in ensuring that there is proper service delivery. This thesis discusses the ways in which citizens participate in local government service delivery in Chiredzi which is an urban Council in Zimbabwe. To establish citizen participation in Chiredzi, this theory draws upon the social capital theory focusing on its trust, network, and norms aspect. Social capital facilitates an analysis of citizen participation and service delivery in Chiredzi. For this study,a qualitative research methodology was used. This methodology consisted of semi-structured telephone interviews with participants together with relevant documents. It was concluded that there is a need to educate citizens on their roles and responsibilities in local government to improve the state of service delivery. , Thesis (MSocSci) -- Faculty of Humanities, Sociology, 2021
- Full Text:
- Date Issued: 2021-10-29
- Authors: Matsilele, Blessing
- Date: 2021-10-29
- Subjects: Municipal services Zimbabwe Chiredzi Rural District , Political participation Zimbabwe Chiredzi Rural District , Social capital (Sociology) Zimbabwe Chiredzi Rural District , Municipal services Zimbabwe Chiredzi Rural District Citizen participation , Community development Zimbabwe Chiredzi Rural District
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/190099 , vital:44963
- Description: Over the years, there have been complaints of poor service delivery in Zimbabwe’s Urban Councils. Newspapers in Zimbabwe have been filled with stories of poor service delivery and citizen grievances. Existing literature on service delivery has focused on the causes of poor service delivery, blaming them solely on the local government authorities. The literature has blamed poor service delivery in Zimbabwe on corruption, polarisation, politicisation, and incapacitation amongst other things. What is not highlighted is the role that citizens play and their responsibility in ensuring that there is proper service delivery. This thesis discusses the ways in which citizens participate in local government service delivery in Chiredzi which is an urban Council in Zimbabwe. To establish citizen participation in Chiredzi, this theory draws upon the social capital theory focusing on its trust, network, and norms aspect. Social capital facilitates an analysis of citizen participation and service delivery in Chiredzi. For this study,a qualitative research methodology was used. This methodology consisted of semi-structured telephone interviews with participants together with relevant documents. It was concluded that there is a need to educate citizens on their roles and responsibilities in local government to improve the state of service delivery. , Thesis (MSocSci) -- Faculty of Humanities, Sociology, 2021
- Full Text:
- Date Issued: 2021-10-29
An analysis of technical efficiency and service effectiveness for freight railways in African and European countries
- Mfiyo, Azania https://orcid.org/0000-0002-0967-9756
- Authors: Mfiyo, Azania https://orcid.org/0000-0002-0967-9756
- Date: 2021-03
- Subjects: Freight and freightage , Railroads -- Freight
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/20186 , vital:45406
- Description: For the past decades, technical efficiency and service effectiveness have become topical as performance measures in various sectors. However, a comparison of technical efficiency and service effectiveness for freight rail transport has received less attention in African and European countries. To address this challenge the current study seeks to analyse technical efficiency and service effectiveness of rail freight in African and European countries. Due to data unavailability in other countries, this study selected four African countries (South Africa, Morocco, Democratic Republic of Congo and Algeria) and four European countries (Lithuania, Austria, France and Germany). The data has been collected from the World Bank, International Union of Railway Statistics and Knoema for the period 2017. Input oriented and output oriented data envelope analysis (DEA) were used to analyze technical efficiency and service effectiveness, respectively. The application of DEA requires the selection of appropriate inputs, production and output variables. This study selected a number of employees and length of rail lines as input variables, gross train tonne kilometres (km) as production variable, tonnes carried and tonne kilometres (km) as output variables. The result shows that five out of eight countries were technical efficient and their services effective with values equal to 1.00. The Pearson correlation coefficient was used to analyse the relationship between technical efficiency and service effectiveness. The results indicate that there is a statistically significant positive correlation between technical efficiency and service effectiveness. To determine the impact exogenous variables on technical efficiency and service effectiveness, a Tobit regression analysis was conducted. The results show that technical efficiency and service effectiveness are not significantly affected by exogenous variables. On the other hand, technical efficiency is significantly affected by the number of employees while service effectiveness is significantly affected by gross train tonne km. This study recommends the use of less labour intensive assets and monitoring of gross train tonne km should be viewed as important strategies to improve technical efficiency and service effectiveness, respectively. , Thesis (MCom) -- Faculty of Management and Commerce, 2021
- Full Text:
- Date Issued: 2021-03
- Authors: Mfiyo, Azania https://orcid.org/0000-0002-0967-9756
- Date: 2021-03
- Subjects: Freight and freightage , Railroads -- Freight
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/20186 , vital:45406
- Description: For the past decades, technical efficiency and service effectiveness have become topical as performance measures in various sectors. However, a comparison of technical efficiency and service effectiveness for freight rail transport has received less attention in African and European countries. To address this challenge the current study seeks to analyse technical efficiency and service effectiveness of rail freight in African and European countries. Due to data unavailability in other countries, this study selected four African countries (South Africa, Morocco, Democratic Republic of Congo and Algeria) and four European countries (Lithuania, Austria, France and Germany). The data has been collected from the World Bank, International Union of Railway Statistics and Knoema for the period 2017. Input oriented and output oriented data envelope analysis (DEA) were used to analyze technical efficiency and service effectiveness, respectively. The application of DEA requires the selection of appropriate inputs, production and output variables. This study selected a number of employees and length of rail lines as input variables, gross train tonne kilometres (km) as production variable, tonnes carried and tonne kilometres (km) as output variables. The result shows that five out of eight countries were technical efficient and their services effective with values equal to 1.00. The Pearson correlation coefficient was used to analyse the relationship between technical efficiency and service effectiveness. The results indicate that there is a statistically significant positive correlation between technical efficiency and service effectiveness. To determine the impact exogenous variables on technical efficiency and service effectiveness, a Tobit regression analysis was conducted. The results show that technical efficiency and service effectiveness are not significantly affected by exogenous variables. On the other hand, technical efficiency is significantly affected by the number of employees while service effectiveness is significantly affected by gross train tonne km. This study recommends the use of less labour intensive assets and monitoring of gross train tonne km should be viewed as important strategies to improve technical efficiency and service effectiveness, respectively. , Thesis (MCom) -- Faculty of Management and Commerce, 2021
- Full Text:
- Date Issued: 2021-03
An analysis of the medicines regulatory environment in sub-Saharan Africa and the African Medicines Regulatory Harmonization Initiative
- Authors: Feka, Cedric Nyahchong
- Date: 2021-10-29
- Subjects: Uncatalogued
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/192408 , vital:45223
- Description: Thesis (MSc (Pharm)) -- Faculty of Pharmacy, Pharmacy, 2021
- Full Text:
- Date Issued: 2021-10-29
- Authors: Feka, Cedric Nyahchong
- Date: 2021-10-29
- Subjects: Uncatalogued
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/192408 , vital:45223
- Description: Thesis (MSc (Pharm)) -- Faculty of Pharmacy, Pharmacy, 2021
- Full Text:
- Date Issued: 2021-10-29
An assessment of the wild cyclopia subternata (vleitee) resource
- Authors: Van der Walt, Wouter
- Date: 2021-04
- Subjects: Legumes -- South Africa , Fynbos -- South Africa , Fynbos ecology -- South Africa , Fynbos -- Harvesting -- South Africa , Biodiversity conservation -- South Africa , Traditional ecological knowledge -- South Africa , Wild Cyclopia Subternata (Vleitee) , Honeybush tea industry
- Language: English
- Type: thesis , text , Masters , MSc
- Identifier: http://hdl.handle.net/10962/176874 , vital:42767
- Description: Cyclopia spp. is used for the production of Honeybush tea, an herbal tea which is used in many cases as a substitute for rooibos tea. The wild harvesting of this fynbos plant still brings in up to 85% of the annual crop and as such needs to be carefully monitored in order to avoid over harvesting and the destruction of biodiversity within the Eastern and Western Cape mountain regions of Southern Africa. Due to the concerns of overharvesting and unsuitable use of the wild resource issues of supply security have been raised. There is a lack of formal knowledge relating to the plant, its harvesting, the industry and its economic potential. This study aimed to amend this scarcity by contributing to the knowledge of C. subternata as a wild harvested plant, the physical environment favoured by C. subternata, sustainable use through harvesting of the wild plant and harvesting methods specific to this honeybush species. The research concludes by presenting a guideline for best harvest practices of the wild C. subternata plant. , Thesis (MSc) -- Faculty of Science, Department of Geography, 2021
- Full Text:
- Date Issued: 2021-04
- Authors: Van der Walt, Wouter
- Date: 2021-04
- Subjects: Legumes -- South Africa , Fynbos -- South Africa , Fynbos ecology -- South Africa , Fynbos -- Harvesting -- South Africa , Biodiversity conservation -- South Africa , Traditional ecological knowledge -- South Africa , Wild Cyclopia Subternata (Vleitee) , Honeybush tea industry
- Language: English
- Type: thesis , text , Masters , MSc
- Identifier: http://hdl.handle.net/10962/176874 , vital:42767
- Description: Cyclopia spp. is used for the production of Honeybush tea, an herbal tea which is used in many cases as a substitute for rooibos tea. The wild harvesting of this fynbos plant still brings in up to 85% of the annual crop and as such needs to be carefully monitored in order to avoid over harvesting and the destruction of biodiversity within the Eastern and Western Cape mountain regions of Southern Africa. Due to the concerns of overharvesting and unsuitable use of the wild resource issues of supply security have been raised. There is a lack of formal knowledge relating to the plant, its harvesting, the industry and its economic potential. This study aimed to amend this scarcity by contributing to the knowledge of C. subternata as a wild harvested plant, the physical environment favoured by C. subternata, sustainable use through harvesting of the wild plant and harvesting methods specific to this honeybush species. The research concludes by presenting a guideline for best harvest practices of the wild C. subternata plant. , Thesis (MSc) -- Faculty of Science, Department of Geography, 2021
- Full Text:
- Date Issued: 2021-04
An ethnographic investigation of the implementation of the bilingual-bicultural approach for educating deaf learners focusing on South African sign language teaching at FET level
- Authors: Tunzelana, Nomava Mercy
- Date: 2021-10-29
- Subjects: South African Sign Language Study and teaching (Higher) , Sign language acquisition South Africa , Education, Bilingual South Africa , Biculturalism South Africa , Ethnology South Africa , Culturally relevant pedagogy South Africa , Deaf students South Africa , South Africa. Department of Basic Education , Curriculum-based assessment South Africa , South African Curriculum Assessment and Policy Statement (CAPS)
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/192353 , vital:45218
- Description: This half-thesis reports on an ethnographic investigation of the implementation of the Bilingual-Bicultural Approach for educating Deaf learners, focusing on South African Sign Language (SASL) teaching at the Further Education and Training (FET) level in a South African School for the Deaf in the Eastern Cape. The investigation occurs within the context of the introduction, in 2015, of the SASL Curriculum and Assessment Policy Statement (CAPS) by the Department of Basic Education (DBE). The SASL CAPS introduces an approach to teaching the Deaf known as the Bilingual-Bicultural Approach. This is an approach in which natural sign language (such as SASL) is taught first and used to learn a spoken language such as English for reading and writing. Previous research on a contrastive analysis of South African English and SASL reveals that SASL is a Topic-Comment language. It is sometimes Object-Subject-Verb (OSV) or Subject-Object-Verb (SOV) while the word order of South African English is Subject-Verb-Object (SVO). Semi-structured interviews of hearing and Deaf participants reveal serious tensions between the staff and the hearing staff because Deaf culture is not adhered to by some of the hearing staff. These tensions have a negative impact on the culture of learning and teaching at the school. Observations of four lessons at an FET class taught by an SASL FET teacher show that in her teaching, SASL syntax is used in keeping with the principles of the Bilingual-Bicultural Approach. However, her signing is accompanied by unvoiced spoken language due to the influence of a previously used approach called Total Communication (TC). One of the learners, Lulu, who contributes considerably more often than other learners in the lesson, also shows the same influence of TC. Other learners are either withdrawn or copy signs from Lulu. The study concludes with the recommendation that SASL be used for initiating newcomers to school as opposed to Signed English because research in bilingualism suggests that second language learners need one natural language established first before attempting to learn a second language. Teachers are recommended to immerse themselves into Deaf culture to acquire fluency. Comments from some participants suggest that teachers require vigorous training in the Bilingual-Bicultural Approach on a continuous basis. , Thesis (MA) -- Faculty of Humanities, Linguistics and Applied Languages Studies, 2021
- Full Text:
- Date Issued: 2021-10-29
- Authors: Tunzelana, Nomava Mercy
- Date: 2021-10-29
- Subjects: South African Sign Language Study and teaching (Higher) , Sign language acquisition South Africa , Education, Bilingual South Africa , Biculturalism South Africa , Ethnology South Africa , Culturally relevant pedagogy South Africa , Deaf students South Africa , South Africa. Department of Basic Education , Curriculum-based assessment South Africa , South African Curriculum Assessment and Policy Statement (CAPS)
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/192353 , vital:45218
- Description: This half-thesis reports on an ethnographic investigation of the implementation of the Bilingual-Bicultural Approach for educating Deaf learners, focusing on South African Sign Language (SASL) teaching at the Further Education and Training (FET) level in a South African School for the Deaf in the Eastern Cape. The investigation occurs within the context of the introduction, in 2015, of the SASL Curriculum and Assessment Policy Statement (CAPS) by the Department of Basic Education (DBE). The SASL CAPS introduces an approach to teaching the Deaf known as the Bilingual-Bicultural Approach. This is an approach in which natural sign language (such as SASL) is taught first and used to learn a spoken language such as English for reading and writing. Previous research on a contrastive analysis of South African English and SASL reveals that SASL is a Topic-Comment language. It is sometimes Object-Subject-Verb (OSV) or Subject-Object-Verb (SOV) while the word order of South African English is Subject-Verb-Object (SVO). Semi-structured interviews of hearing and Deaf participants reveal serious tensions between the staff and the hearing staff because Deaf culture is not adhered to by some of the hearing staff. These tensions have a negative impact on the culture of learning and teaching at the school. Observations of four lessons at an FET class taught by an SASL FET teacher show that in her teaching, SASL syntax is used in keeping with the principles of the Bilingual-Bicultural Approach. However, her signing is accompanied by unvoiced spoken language due to the influence of a previously used approach called Total Communication (TC). One of the learners, Lulu, who contributes considerably more often than other learners in the lesson, also shows the same influence of TC. Other learners are either withdrawn or copy signs from Lulu. The study concludes with the recommendation that SASL be used for initiating newcomers to school as opposed to Signed English because research in bilingualism suggests that second language learners need one natural language established first before attempting to learn a second language. Teachers are recommended to immerse themselves into Deaf culture to acquire fluency. Comments from some participants suggest that teachers require vigorous training in the Bilingual-Bicultural Approach on a continuous basis. , Thesis (MA) -- Faculty of Humanities, Linguistics and Applied Languages Studies, 2021
- Full Text:
- Date Issued: 2021-10-29
An evolutionary study of legless skinks’ (Acontias Cuvier, 1817) head and vertebrae morphology
- Authors: Evlambiou, Anthony Andreas
- Date: 2021-10
- Subjects: Skinks South Africa , Acontias South Africa , Typhlosaurus South Africa , Acontias Morphology , Acontias Phylogeny , Acontias Evolution , Vertebrae , Skull Growth , Evolutionary developmental biology
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/190690 , vital:45018
- Description: Environmental factors and/or processes can produce differences in general shape between individuals or particular parts of individuals. Examples of these biological processes may include ontogenetic development, adaptation to local geographic factors, or long-term evolutionary diversification. An organism is not likely to be able to optimise a single structure for multiple purposes and so trade-offs are likely to occur. An example of such a structure is the cranium, as it can be used for multiple activities such as defensive and sexual behaviour, locomotion, prey capture, and ingestion. Morphological characteristics have historically been used in the description of species. Genetic analyses have gained popularity as species delineation techniques and have been particularly useful in identifying cryptic species, especially among morphological conserved species like legless skinks of the subfamily Acontinae (e.g. Acontias Cuvier, 1817 and Typhlosaurus Weigmann, 1834). However, completely doing away with morphological techniques during species descriptions is not the best option. Therefore, novel methods to identify species, especially those with similar body plans, are needed. In this dissertation, we explore the links between head shape and vertebral number to environmental pressures to determine whether the evolutionary process is driven by environmental pressures (soil or biome) or is retained through ancestry. A novel species/clade delineation linked to vertebral number is also investigated. Head shape was expected to have a close link to the environment and the number of vertebrae was expected to have a closer link to ancestry. The first chapter investigates the drivers behind Acontias head shape evolution using geometric morphometric techniques. We found that environmental pressures did affect the evolution of head shape especially in the “soil” and “biome” categories but further investigation is advised. The second chapter explores the viability of using vertebral counts as a novel method for species and/or clade delineation in Acontias and to determine whether vertebral number can be linked to the environment. Delineating species based on vertebral count is likely not an option, however, delineating clades proved to show promising results. A link between vertebral count and environment was found in Acontias with larger bodied species occurring in different environments to smaller body species. In conclusion, the genus Acontias is difficult to delineate morphologically. Genetic sequence analyses can indicate differences and delineate the species. Even though there were differences in morphology based on environmental factors, it is not sufficient to delineate this subfamily alone. Further research is advised and this dissertation provides a good basis to work with. , Thesis (MSc) -- Faculty of Science, Zoology and Entomology, 2021
- Full Text:
- Date Issued: 2021-10
- Authors: Evlambiou, Anthony Andreas
- Date: 2021-10
- Subjects: Skinks South Africa , Acontias South Africa , Typhlosaurus South Africa , Acontias Morphology , Acontias Phylogeny , Acontias Evolution , Vertebrae , Skull Growth , Evolutionary developmental biology
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/190690 , vital:45018
- Description: Environmental factors and/or processes can produce differences in general shape between individuals or particular parts of individuals. Examples of these biological processes may include ontogenetic development, adaptation to local geographic factors, or long-term evolutionary diversification. An organism is not likely to be able to optimise a single structure for multiple purposes and so trade-offs are likely to occur. An example of such a structure is the cranium, as it can be used for multiple activities such as defensive and sexual behaviour, locomotion, prey capture, and ingestion. Morphological characteristics have historically been used in the description of species. Genetic analyses have gained popularity as species delineation techniques and have been particularly useful in identifying cryptic species, especially among morphological conserved species like legless skinks of the subfamily Acontinae (e.g. Acontias Cuvier, 1817 and Typhlosaurus Weigmann, 1834). However, completely doing away with morphological techniques during species descriptions is not the best option. Therefore, novel methods to identify species, especially those with similar body plans, are needed. In this dissertation, we explore the links between head shape and vertebral number to environmental pressures to determine whether the evolutionary process is driven by environmental pressures (soil or biome) or is retained through ancestry. A novel species/clade delineation linked to vertebral number is also investigated. Head shape was expected to have a close link to the environment and the number of vertebrae was expected to have a closer link to ancestry. The first chapter investigates the drivers behind Acontias head shape evolution using geometric morphometric techniques. We found that environmental pressures did affect the evolution of head shape especially in the “soil” and “biome” categories but further investigation is advised. The second chapter explores the viability of using vertebral counts as a novel method for species and/or clade delineation in Acontias and to determine whether vertebral number can be linked to the environment. Delineating species based on vertebral count is likely not an option, however, delineating clades proved to show promising results. A link between vertebral count and environment was found in Acontias with larger bodied species occurring in different environments to smaller body species. In conclusion, the genus Acontias is difficult to delineate morphologically. Genetic sequence analyses can indicate differences and delineate the species. Even though there were differences in morphology based on environmental factors, it is not sufficient to delineate this subfamily alone. Further research is advised and this dissertation provides a good basis to work with. , Thesis (MSc) -- Faculty of Science, Zoology and Entomology, 2021
- Full Text:
- Date Issued: 2021-10
An exploration of how schools and teachers interpret and implement the Language in Education Policy for their classroom practice: a case study
- Authors: Sibanda, Sikhumbuzo
- Date: 2021-10-29
- Subjects: Language policy South Africa , Education and state South Africa , Critical discourse analysis , Native language and education South Africa Kuruman , Educational change South Africa , South Africa Colonial influence , South African Language in Education Policy
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/192035 , vital:45190
- Description: This case study explored how schools and teachers interpret and implement the Language in Education Policy for their classroom practices. Scholars like Alexander and Block (2012) note that the South African Language in Education Policy (LiEP) is one of the advanced policies globally. Other scholars like Perry (2015) and Ngcobo (2015) state that the policy in South Africa has failed when it comes to implementation. It is against this background that the research explored how schools and teachers interpret and implement the Language in Education Policy for their classroom practice in three primary schools in Kuruman, Northern Cape. The research methodology was qualitative and it used a case study approach. The study is informed and framed by the Language Policy framework and the CDA (Critical Discourse Analysis). The research sites were three Grade 4 classes and the participants were three teachers, three principals and three SGB Chairpersons from three different schools (one school in deep rural, another in semi-urban and the third in urban) in Kuruman. This case study, located in the interpretive paradigm, employed individual semi-structured interviews, non-participant classroom observations, document analyses and field notes for data collection. The study revealed that teachers are not versed in LiEP and their classroom practice is therefore not based on policy but on their own perceptions. Classroom practices were incongruent with what the Language in Education Policy requires. Even other documents which support the Language in Education Policy like the school language policies, were not used as guiding documents for classroom practice. Lastly, this study revealed that, despite a plethora of literature on how practice engages and disengages with Language in Education Policy (LiEP), the deconstruction of colonial and apartheid education is still a challenge especially in language use, perceptions of mother tongue instruction and the hegemony of English. One of the recommendations of this study is that teachers must be taught to use Languages of Learning and teaching required in their areas and they should also be given continuous professional development courses on policies so as to improve their practice. Language Policy Units should be set up within the provincial and district Departments of Education that would support the implementation of LiEP. , Thesis (MEd) -- Faculty of Education, Education, 2021
- Full Text:
- Date Issued: 2021-10-29
- Authors: Sibanda, Sikhumbuzo
- Date: 2021-10-29
- Subjects: Language policy South Africa , Education and state South Africa , Critical discourse analysis , Native language and education South Africa Kuruman , Educational change South Africa , South Africa Colonial influence , South African Language in Education Policy
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/192035 , vital:45190
- Description: This case study explored how schools and teachers interpret and implement the Language in Education Policy for their classroom practices. Scholars like Alexander and Block (2012) note that the South African Language in Education Policy (LiEP) is one of the advanced policies globally. Other scholars like Perry (2015) and Ngcobo (2015) state that the policy in South Africa has failed when it comes to implementation. It is against this background that the research explored how schools and teachers interpret and implement the Language in Education Policy for their classroom practice in three primary schools in Kuruman, Northern Cape. The research methodology was qualitative and it used a case study approach. The study is informed and framed by the Language Policy framework and the CDA (Critical Discourse Analysis). The research sites were three Grade 4 classes and the participants were three teachers, three principals and three SGB Chairpersons from three different schools (one school in deep rural, another in semi-urban and the third in urban) in Kuruman. This case study, located in the interpretive paradigm, employed individual semi-structured interviews, non-participant classroom observations, document analyses and field notes for data collection. The study revealed that teachers are not versed in LiEP and their classroom practice is therefore not based on policy but on their own perceptions. Classroom practices were incongruent with what the Language in Education Policy requires. Even other documents which support the Language in Education Policy like the school language policies, were not used as guiding documents for classroom practice. Lastly, this study revealed that, despite a plethora of literature on how practice engages and disengages with Language in Education Policy (LiEP), the deconstruction of colonial and apartheid education is still a challenge especially in language use, perceptions of mother tongue instruction and the hegemony of English. One of the recommendations of this study is that teachers must be taught to use Languages of Learning and teaching required in their areas and they should also be given continuous professional development courses on policies so as to improve their practice. Language Policy Units should be set up within the provincial and district Departments of Education that would support the implementation of LiEP. , Thesis (MEd) -- Faculty of Education, Education, 2021
- Full Text:
- Date Issued: 2021-10-29
An interpretative phenomenological analysis of mothers’ experiences raising an autistic child
- Authors: Hewson, Aimee Jessica
- Date: 2021-10-29
- Subjects: Autism spectrum disorders South Africa , Autism spectrum disorders in children South Africa , Mothers of children with disabilities South Africa , Phenomenological psychology , Qualitative research , Interpretative phenomenological analysis
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/190725 , vital:45022
- Description: There has been an increasing research focus on Autism Spectrum Disorder (ASD) and the experiences of those affected by autism. Previous research has demonstrated that mothers experience difficulties in all spheres related to their autistic child. Mothers were focused on exclusively in this study as previous research found that it is mostly mothers who take on the primary caring role for their children. As a result, this research aimed to explore the perceptions and experience of six South African mothers raising their ASD child. This research used a qualitative research approach and an interpretative phenomenological analysis methodology. Two semi-structured interviews were held with each participant, with interviews being audio recorded. After analysis, five themes were found, namely: (1) learning their child has a condition or diagnosis, (2) learning and sharing about ASD, (3) the mothering experience, (4) interventions and cost and (5) supportive resources. Careful anonymisation choices were made in this research to ensure the anonymity of participants as best as possible, due to the recruitment through a gatekeeper organisation and snowball sampling. The main findings of this study were that mothers experienced difficulties and challenges as they navigated the medical world in search of a diagnosis for their child. Mothers also reported following their intuition when it came to their children’s care, interventions, and schooling. The passage of time was a significant issue to mothers, as they described several delays and waiting periods. Mothers also described their concerns regarding their children’s future and the fact that their child would be dependent on them and would not be able to form autonomous mature relationships with others. They also reported various thoughts on disclosing their child’s diagnosis to their children. This research, therefore, added to and expanded upon South African literature on the experiences of mothers raising their ASD child. Concurring with previous research, this project found that mothers experience many challenges in the raising of their ASD child. , Thesis (MSocSci) -- Faculty of Humanities, Psychology, 2021
- Full Text:
- Date Issued: 2021-10-29
- Authors: Hewson, Aimee Jessica
- Date: 2021-10-29
- Subjects: Autism spectrum disorders South Africa , Autism spectrum disorders in children South Africa , Mothers of children with disabilities South Africa , Phenomenological psychology , Qualitative research , Interpretative phenomenological analysis
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/190725 , vital:45022
- Description: There has been an increasing research focus on Autism Spectrum Disorder (ASD) and the experiences of those affected by autism. Previous research has demonstrated that mothers experience difficulties in all spheres related to their autistic child. Mothers were focused on exclusively in this study as previous research found that it is mostly mothers who take on the primary caring role for their children. As a result, this research aimed to explore the perceptions and experience of six South African mothers raising their ASD child. This research used a qualitative research approach and an interpretative phenomenological analysis methodology. Two semi-structured interviews were held with each participant, with interviews being audio recorded. After analysis, five themes were found, namely: (1) learning their child has a condition or diagnosis, (2) learning and sharing about ASD, (3) the mothering experience, (4) interventions and cost and (5) supportive resources. Careful anonymisation choices were made in this research to ensure the anonymity of participants as best as possible, due to the recruitment through a gatekeeper organisation and snowball sampling. The main findings of this study were that mothers experienced difficulties and challenges as they navigated the medical world in search of a diagnosis for their child. Mothers also reported following their intuition when it came to their children’s care, interventions, and schooling. The passage of time was a significant issue to mothers, as they described several delays and waiting periods. Mothers also described their concerns regarding their children’s future and the fact that their child would be dependent on them and would not be able to form autonomous mature relationships with others. They also reported various thoughts on disclosing their child’s diagnosis to their children. This research, therefore, added to and expanded upon South African literature on the experiences of mothers raising their ASD child. Concurring with previous research, this project found that mothers experience many challenges in the raising of their ASD child. , Thesis (MSocSci) -- Faculty of Humanities, Psychology, 2021
- Full Text:
- Date Issued: 2021-10-29
An interpretive analysis of the experiences of adults working as university support staff
- Authors: Zini, Thembela Nomonde
- Date: 2021-10-29
- Subjects: Universities and colleges South Africa , Universities and colleges Employees , Universities and colleges Sociological aspects , Identity (Psychology) , Identity (Psychology) Social aspects , Work Psychological aspects , Work Social aspects , Interpretive Phenomenological Analysis (IPA)
- Language: English
- Type: Masters theses , text
- Identifier: http://hdl.handle.net/10962/188888 , vital:44795
- Description: Work means different things to different people and the different meanings they make of their work has the unique ability of contributing to a sense of identity. Support staff have to negotiate their personal identities and social identities to develop a work identity in the complex South African context that has its unique challenges. Exploring how support staff make sense of their experiences, when it comes to their identities, reveals what identity work strategies they use. An interpretative phenomenological method of inquiry was employed as an initial research method to explore the aspects that impact on the identity formation of support staff at Rhodes University. The study aims to investigate how support staff have constructed a work identity through their constructions of their experiences. Six participants were recruited through a purposive sampling method and data were collected using semi-structured interviews. The study revealed that support staff use the following identity work strategies to negotiate their identities: Financial, Personality, Career mobility, Roles, Status and Esteem, Subjective wellbeing. These themes were derived from the narratives of the participants, using the emphases in the data and suggest that support staff use identity work strategies both outside and within the workplace, when constructing their work identities. The study illustrates that as people ascribe different meanings to work, they will define and negotiate their identities in the workplace based upon those meanings. Identity work is indeed challenging for support staff because they need to use identity strategies that are enhancing to their self-esteem. Identity work is a challenging task because of the many tensions and demands of modern society, as adults negotiate their needs to provide for families and to find ways to construct their job status in positive ways. , Thesis (MA) -- Faculty of Humanities, Psychology, 2021
- Full Text:
- Date Issued: 2021-10-29
- Authors: Zini, Thembela Nomonde
- Date: 2021-10-29
- Subjects: Universities and colleges South Africa , Universities and colleges Employees , Universities and colleges Sociological aspects , Identity (Psychology) , Identity (Psychology) Social aspects , Work Psychological aspects , Work Social aspects , Interpretive Phenomenological Analysis (IPA)
- Language: English
- Type: Masters theses , text
- Identifier: http://hdl.handle.net/10962/188888 , vital:44795
- Description: Work means different things to different people and the different meanings they make of their work has the unique ability of contributing to a sense of identity. Support staff have to negotiate their personal identities and social identities to develop a work identity in the complex South African context that has its unique challenges. Exploring how support staff make sense of their experiences, when it comes to their identities, reveals what identity work strategies they use. An interpretative phenomenological method of inquiry was employed as an initial research method to explore the aspects that impact on the identity formation of support staff at Rhodes University. The study aims to investigate how support staff have constructed a work identity through their constructions of their experiences. Six participants were recruited through a purposive sampling method and data were collected using semi-structured interviews. The study revealed that support staff use the following identity work strategies to negotiate their identities: Financial, Personality, Career mobility, Roles, Status and Esteem, Subjective wellbeing. These themes were derived from the narratives of the participants, using the emphases in the data and suggest that support staff use identity work strategies both outside and within the workplace, when constructing their work identities. The study illustrates that as people ascribe different meanings to work, they will define and negotiate their identities in the workplace based upon those meanings. Identity work is indeed challenging for support staff because they need to use identity strategies that are enhancing to their self-esteem. Identity work is a challenging task because of the many tensions and demands of modern society, as adults negotiate their needs to provide for families and to find ways to construct their job status in positive ways. , Thesis (MA) -- Faculty of Humanities, Psychology, 2021
- Full Text:
- Date Issued: 2021-10-29
An Updated Catalogue and Review of Afrotherian (Afroplacentalia) Mammals in the Amathole Museum Collection, Eastern Cape Province, South Africa
- Authors: Mahala, Buyiswa
- Date: 2021-03
- Subjects: Mammals
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/20741 , vital:46513
- Description: The Mammalogy Collection of the Amathole Museum is one of the most comprehensive mammal collections in Africa, with a specialisation in southern African fauna. It was accumulated over almost 100 years, in some instances from areas that no longer support sustainable populations of wildlife. The collection, therefore, is irreplaceable. A museum collection is only as good as its accessibility to students and researchers for it to perform its functions as a biodiversity archive. Accessibility, in turn, depends on up-to-date taxonomy and classification; good curation practices; public awareness of the collection; and electronic access to the details of the collection’s composition. The higher-level taxonomy of the Class Mammalia has undergone extensive changes since the adoption of molecular systematic techniques. Phylogenetic reconstructions based on large DNA sequence databases consistently group placental mammals into four superorders: Laurasiatheria (carnivores, bats, ungulates, whales); Euarchontoglires, a super-clade that includes primates (apes, monkeys and allies), rodents (mouse, rat and guinea pig), lagomorphs, (rabbit and hares), dermopterans (flying lemurs or colugos) and scandentians (tree shrew); Xenarthra (armadillos, anteaters, sloths), and Afrotheria (elephants, sea cows, tenrecs, aardvarks, sengis, golden moles, hyraxes). New relationships have been recognised that have required the erection of new taxonomic groups. Most of the Amathole Museum mammal collection was assembled and accessioned long before this new system was devised, and I undertook this project to begin the re-organisation of the collection according to the new information. I conducted and audit and inventory of all specimens of Afrotheria, or the mammals of African origin, housed in the Amathole Museum collection. I photographed the specimens and corrected and updated their taxonomic details. As we now live in an age of digital information, natural history collections need to be available online to extend public access. Specimen details were entered into Excel files, and their localities were mapped. This kind of information has the possibility of transforming biological curricula to include more authentic and inquiry-driven educational experiences. My future goals are to acquire Malagasy tenrecs for the Amathole Afrotheria collection, and to investigate the taxonomic validity of the Amathole hyrax collection, as many specimens were found with confusing and out-of-date classifications. , Thesis (MSc) (Zoology) -- University of Fort Hare, 2021
- Full Text:
- Date Issued: 2021-03
- Authors: Mahala, Buyiswa
- Date: 2021-03
- Subjects: Mammals
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/20741 , vital:46513
- Description: The Mammalogy Collection of the Amathole Museum is one of the most comprehensive mammal collections in Africa, with a specialisation in southern African fauna. It was accumulated over almost 100 years, in some instances from areas that no longer support sustainable populations of wildlife. The collection, therefore, is irreplaceable. A museum collection is only as good as its accessibility to students and researchers for it to perform its functions as a biodiversity archive. Accessibility, in turn, depends on up-to-date taxonomy and classification; good curation practices; public awareness of the collection; and electronic access to the details of the collection’s composition. The higher-level taxonomy of the Class Mammalia has undergone extensive changes since the adoption of molecular systematic techniques. Phylogenetic reconstructions based on large DNA sequence databases consistently group placental mammals into four superorders: Laurasiatheria (carnivores, bats, ungulates, whales); Euarchontoglires, a super-clade that includes primates (apes, monkeys and allies), rodents (mouse, rat and guinea pig), lagomorphs, (rabbit and hares), dermopterans (flying lemurs or colugos) and scandentians (tree shrew); Xenarthra (armadillos, anteaters, sloths), and Afrotheria (elephants, sea cows, tenrecs, aardvarks, sengis, golden moles, hyraxes). New relationships have been recognised that have required the erection of new taxonomic groups. Most of the Amathole Museum mammal collection was assembled and accessioned long before this new system was devised, and I undertook this project to begin the re-organisation of the collection according to the new information. I conducted and audit and inventory of all specimens of Afrotheria, or the mammals of African origin, housed in the Amathole Museum collection. I photographed the specimens and corrected and updated their taxonomic details. As we now live in an age of digital information, natural history collections need to be available online to extend public access. Specimen details were entered into Excel files, and their localities were mapped. This kind of information has the possibility of transforming biological curricula to include more authentic and inquiry-driven educational experiences. My future goals are to acquire Malagasy tenrecs for the Amathole Afrotheria collection, and to investigate the taxonomic validity of the Amathole hyrax collection, as many specimens were found with confusing and out-of-date classifications. , Thesis (MSc) (Zoology) -- University of Fort Hare, 2021
- Full Text:
- Date Issued: 2021-03
Application of computer-aided drug design for identification of P. falciparum inhibitors
- Authors: Diallo, Bakary N’tji
- Date: 2021-10-29
- Subjects: Plasmodium falciparum , Malaria -- Chemotherapy , Molecular dynamics , Antimalarials , Cheminformatics , Drug development , Ligand binding (Biochemistry) , Plasmodium falciparum1-deoxy-D-xylulose-5-phosphate reductoisomerase (PfDXR) , South African Natural Compounds Database
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/192798 , vital:45265 , 10.21504/10962/192798
- Description: Malaria is a millennia-old disease with the first recorded cases dating back to 2700 BC found in Chinese medical records, and later in other civilizations. It has claimed human lives to such an extent that there are a notable associated socio-economic consequences. Currently, according to the World Health Organization (WHO), Africa holds the highest disease burden with 94% of deaths and 82% of cases with P. falciparum having ~100% prevalence. Chemotherapy, such as artemisinin combination therapy, has been and continues to be the work horse in the fight against the disease, together with seasonal malaria chemoprevention and the use of insecticides. Natural products such as quinine and artemisinin are particularly important in terms of their antimalarial activity. The emphasis in current chemotherapy research is the need for time and cost-effective workflows focussed on new mechanisms of action (MoAs) covering the target candidate profiles (TCPs). Despite a decline in cases over the past decades with, countries increasingly becoming certified malaria free, a stalling trend has been observed in the past five years resulting in missing the 2020 Global Technical Strategy (GTS) milestones. With no effective vaccine, a reduction in funding, slower drug approval than resistance emergence from resistant and invasive vectors, and threats in diagnosis with the pfhrp2/3 gene deletion, malaria remains a major health concern. Motivated by these reasons, the primary aim of this work was a contribution to the antimalarial pipeline through in silico approaches focusing on P. falciparum. We first intended an exploration of malarial targets through a proteome scale screening on 36 targets using multiple metrics to account for the multi-objective nature of drug discovery. The continuous growth of structural data offers the ideal scenario for mining new MoAs covering antimalarials TCPs. This was combined with a repurposing strategy using a set of orally available FDA approved drugs. Further, use was made of time- and cost-effective strategies combining QVina-W efficiency metrics that integrate molecular properties, GRIM rescoring for molecular interactions and a hydrogen mass repartitioning (HMR) molecular dynamics (MD) scheme for accelerated development of antimalarials in the context of resistance. This pipeline further integrates a complex ranking for better drug-target selectivity, and normalization strategies to overcome docking scoring function bias. The different metrics, ranking, normalization strategies and their combinations were first assessed using their mean ranking error (MRE). A version combining all metrics was used to select 36 unique protein-ligand complexes, assessed in MD, with the final retention of 25. From the 16 in vitro tested hits of the 25, fingolimod, abiraterone, prazosin, and terazosin showed antiplasmodial activity with IC50 2.21, 3.37, 16.67 and 34.72 μM respectively and of these, only fingolimod was found to be not safe with respect to human cell viability. These compounds were predicted active on different molecular targets, abiraterone was predicted to interact with a putative liver-stage essential target, hence promising as a transmission-blocking agent. The pipeline had a promising 25% hit rate considering the proteome-scale and use of cost-effective approaches. Secondly, we focused on Plasmodium falciparum 1-deoxy-D-xylulose-5-phosphate reductoisomerase (PfDXR) using a more extensive screening pipeline to overcome some of the current in silico screening limitations. Starting from the ZINC lead-like library of ~3M, hierarchical ligand-based virtual screening (LBVS) and structure-based virtual screening (SBVS) approaches with molecular docking and re-scoring using eleven scoring functions (SFs) were used. Later ranking with an exponential consensus strategy was included. Selected hits were further assessed through Molecular Mechanics Poisson-Boltzmann Surface Area (MM-PBSA), advanced MD sampling in a ligand pulling simulations and (Weighted Histogram Analysis Method) WHAM analysis for umbrella sampling (US) to derive binding free energies. Four leads had better predicted affinities in US than LC5, a 280 nM potent PfDXR inhibitor with ZINC000050633276 showing a promising binding of -20.43 kcal/mol. As shown with fosmidomycin, DXR inhibition offers fast acting compounds fulfilling antimalarials TCP1. Yet, fosmidomycin has a high polarity causing its short half-life and hampering its clinical use. These leads scaffolds are different from fosmidomycin and hence may offer better pharmacokinetic and pharmacodynamic properties and may also be promising for lead optimization. A combined analysis of residues’ contributions to the free energy of binding in MM-PBSA and to steered molecular dynamics (SMD) Fmax indicated GLU233, CYS268, SER270, TRP296, and HIS341 as exploitable for compound optimization. Finally, we updated the SANCDB library with new NPs and their commercially available analogs as a solution to NP availability. The library is extended to 1005 compounds from its initial 600 compounds and the database is integrated to Mcule and Molport APIs for analogs automatic update. The new set may contribute to virtual screening and to antimalarials as the most effective ones have NP origin. , Thesis (PhD) -- Faculty of Science, Biochemistry and Microbiology, 2021
- Full Text:
- Date Issued: 2021-10-29
- Authors: Diallo, Bakary N’tji
- Date: 2021-10-29
- Subjects: Plasmodium falciparum , Malaria -- Chemotherapy , Molecular dynamics , Antimalarials , Cheminformatics , Drug development , Ligand binding (Biochemistry) , Plasmodium falciparum1-deoxy-D-xylulose-5-phosphate reductoisomerase (PfDXR) , South African Natural Compounds Database
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/192798 , vital:45265 , 10.21504/10962/192798
- Description: Malaria is a millennia-old disease with the first recorded cases dating back to 2700 BC found in Chinese medical records, and later in other civilizations. It has claimed human lives to such an extent that there are a notable associated socio-economic consequences. Currently, according to the World Health Organization (WHO), Africa holds the highest disease burden with 94% of deaths and 82% of cases with P. falciparum having ~100% prevalence. Chemotherapy, such as artemisinin combination therapy, has been and continues to be the work horse in the fight against the disease, together with seasonal malaria chemoprevention and the use of insecticides. Natural products such as quinine and artemisinin are particularly important in terms of their antimalarial activity. The emphasis in current chemotherapy research is the need for time and cost-effective workflows focussed on new mechanisms of action (MoAs) covering the target candidate profiles (TCPs). Despite a decline in cases over the past decades with, countries increasingly becoming certified malaria free, a stalling trend has been observed in the past five years resulting in missing the 2020 Global Technical Strategy (GTS) milestones. With no effective vaccine, a reduction in funding, slower drug approval than resistance emergence from resistant and invasive vectors, and threats in diagnosis with the pfhrp2/3 gene deletion, malaria remains a major health concern. Motivated by these reasons, the primary aim of this work was a contribution to the antimalarial pipeline through in silico approaches focusing on P. falciparum. We first intended an exploration of malarial targets through a proteome scale screening on 36 targets using multiple metrics to account for the multi-objective nature of drug discovery. The continuous growth of structural data offers the ideal scenario for mining new MoAs covering antimalarials TCPs. This was combined with a repurposing strategy using a set of orally available FDA approved drugs. Further, use was made of time- and cost-effective strategies combining QVina-W efficiency metrics that integrate molecular properties, GRIM rescoring for molecular interactions and a hydrogen mass repartitioning (HMR) molecular dynamics (MD) scheme for accelerated development of antimalarials in the context of resistance. This pipeline further integrates a complex ranking for better drug-target selectivity, and normalization strategies to overcome docking scoring function bias. The different metrics, ranking, normalization strategies and their combinations were first assessed using their mean ranking error (MRE). A version combining all metrics was used to select 36 unique protein-ligand complexes, assessed in MD, with the final retention of 25. From the 16 in vitro tested hits of the 25, fingolimod, abiraterone, prazosin, and terazosin showed antiplasmodial activity with IC50 2.21, 3.37, 16.67 and 34.72 μM respectively and of these, only fingolimod was found to be not safe with respect to human cell viability. These compounds were predicted active on different molecular targets, abiraterone was predicted to interact with a putative liver-stage essential target, hence promising as a transmission-blocking agent. The pipeline had a promising 25% hit rate considering the proteome-scale and use of cost-effective approaches. Secondly, we focused on Plasmodium falciparum 1-deoxy-D-xylulose-5-phosphate reductoisomerase (PfDXR) using a more extensive screening pipeline to overcome some of the current in silico screening limitations. Starting from the ZINC lead-like library of ~3M, hierarchical ligand-based virtual screening (LBVS) and structure-based virtual screening (SBVS) approaches with molecular docking and re-scoring using eleven scoring functions (SFs) were used. Later ranking with an exponential consensus strategy was included. Selected hits were further assessed through Molecular Mechanics Poisson-Boltzmann Surface Area (MM-PBSA), advanced MD sampling in a ligand pulling simulations and (Weighted Histogram Analysis Method) WHAM analysis for umbrella sampling (US) to derive binding free energies. Four leads had better predicted affinities in US than LC5, a 280 nM potent PfDXR inhibitor with ZINC000050633276 showing a promising binding of -20.43 kcal/mol. As shown with fosmidomycin, DXR inhibition offers fast acting compounds fulfilling antimalarials TCP1. Yet, fosmidomycin has a high polarity causing its short half-life and hampering its clinical use. These leads scaffolds are different from fosmidomycin and hence may offer better pharmacokinetic and pharmacodynamic properties and may also be promising for lead optimization. A combined analysis of residues’ contributions to the free energy of binding in MM-PBSA and to steered molecular dynamics (SMD) Fmax indicated GLU233, CYS268, SER270, TRP296, and HIS341 as exploitable for compound optimization. Finally, we updated the SANCDB library with new NPs and their commercially available analogs as a solution to NP availability. The library is extended to 1005 compounds from its initial 600 compounds and the database is integrated to Mcule and Molport APIs for analogs automatic update. The new set may contribute to virtual screening and to antimalarials as the most effective ones have NP origin. , Thesis (PhD) -- Faculty of Science, Biochemistry and Microbiology, 2021
- Full Text:
- Date Issued: 2021-10-29
Assessing the invasive status and reproductive ecology of two Crataegus species in South Africa; Crataegus monogyna Jacq and C. mexicana DC
- Authors: Tshilingalinga, Sydney
- Date: 2021-03
- Subjects: Crataegus monogyna , Nonindigenous pests , Biological invasions
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/20904 , vital:46740
- Description: In South Africa different species, from the genus Crataegus, including Crataegus monogyna Jacq and C. mexicana DC have been introduced for various reasons in the past. Populations of these plants have now established in multiple provinces. However, the invasive status, risk and insect pollinators that promote their reproduction and dispersal have never been studied in South Africa. This study was aimed at 1) Assessing the risk of, and mapping two Crataegus species, Crataegus monogyna Jacq and C. mexicana DC in South Africa, 2) Determining the role and effectiveness of insects pollinators to fruiting of C. monogyna and C. mexicana, 3) Identifying flower visitors of C. monogyna and C. mexicana, and 4) documenting potential dispersal vectors for both species in the Eastern Cape Province. A framework entitled “Framework and guideline for conducting risk analysis under NEM: BA Alien and Invasive Species Regulation of 2014” was used to assess the risk of the two Crataegus spp, and we conducted field trips to various provinces in SA to map their distribution. The author conducted an exclusion experiment to determine the role and effectiveness of insect pollinators. Observations were conducted to identify flower visitors and potential dispersal vectors for both species. The risk analysis results suggested that both species pose a high risk of becoming invasive in South Africa. The eradication feasibility of both species was found to be medium with C. monogyna having an eradication feasibility score of 5 and C. mexicana having an eradication feasibility score of 4. This meant that there was a 50 percent chance for both species to be eradicated in South Africa currently. After a thorough risk analysis, it was recommended that both species be listed under category 1b on the National Environmental Management Biodiversity Act. Category 1b species are invasive species that need to be controlled, and if possible, they must be eradicated, trading of species from this category is not allowed. Crataegus mexicana was found to be widespread in South Africa with ten relatively small populations distributed in 5 provinces; Limpopo, Mpumalanga, KwaZulu-Natal, Free State and Eastern Cape Province. Crataegus monogyna was found not to be widespread in South Africa, with only three populations found in the Eastern Cape Province. Insect pollinators contribute to the fruiting of both species in SA. However, the exotic plants were also observed to be able to self-pollinate when insects are excluded. Flowers of C. monogyna were visited by various insect species from orders Lepidoptera, Hymenoptera, Coleoptera and Diptera, while C. mexicana is visited by species from the order Hymenoptera, Diptera, Lepidoptera and Coleoptera. Seventy-seven percent (77 percent) of potential dispersal vectors observed for C. monogyna were birds, and 15 percent were mammals. For C. mexicana, 71 percent of potential dispersal vectors observed were mammals, and 29 percent were birds. Crataegus monogyna and C. mexicana are emerging invasive alien species in South Africa, and not much is known about them. Although the two species are listed as invasive weeds in South Africa, very little is known about their invasive status in other parts of the world. This study has managed to give baseline information and data about both species which are already in South Africa. The baseline information and data include the population structure of both species, their distribution, the risk they pose to South Africa biodiversity and their reproduction ecology. Currently, there are no management plans in place for both species in South Africa, and this is because they are not listed yet in the National Environmental Management Biodiversity Act of South Africa. However, this study recommends that current populations continue to be monitored, awareness of both species in various provinces be initiated to help in the discovery of new and emerging populations, and management options of large populations developed in the future. , Thesis (MSc) (Entomology) -- University of Fort Hare, 2021
- Full Text:
- Date Issued: 2021-03
- Authors: Tshilingalinga, Sydney
- Date: 2021-03
- Subjects: Crataegus monogyna , Nonindigenous pests , Biological invasions
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/20904 , vital:46740
- Description: In South Africa different species, from the genus Crataegus, including Crataegus monogyna Jacq and C. mexicana DC have been introduced for various reasons in the past. Populations of these plants have now established in multiple provinces. However, the invasive status, risk and insect pollinators that promote their reproduction and dispersal have never been studied in South Africa. This study was aimed at 1) Assessing the risk of, and mapping two Crataegus species, Crataegus monogyna Jacq and C. mexicana DC in South Africa, 2) Determining the role and effectiveness of insects pollinators to fruiting of C. monogyna and C. mexicana, 3) Identifying flower visitors of C. monogyna and C. mexicana, and 4) documenting potential dispersal vectors for both species in the Eastern Cape Province. A framework entitled “Framework and guideline for conducting risk analysis under NEM: BA Alien and Invasive Species Regulation of 2014” was used to assess the risk of the two Crataegus spp, and we conducted field trips to various provinces in SA to map their distribution. The author conducted an exclusion experiment to determine the role and effectiveness of insect pollinators. Observations were conducted to identify flower visitors and potential dispersal vectors for both species. The risk analysis results suggested that both species pose a high risk of becoming invasive in South Africa. The eradication feasibility of both species was found to be medium with C. monogyna having an eradication feasibility score of 5 and C. mexicana having an eradication feasibility score of 4. This meant that there was a 50 percent chance for both species to be eradicated in South Africa currently. After a thorough risk analysis, it was recommended that both species be listed under category 1b on the National Environmental Management Biodiversity Act. Category 1b species are invasive species that need to be controlled, and if possible, they must be eradicated, trading of species from this category is not allowed. Crataegus mexicana was found to be widespread in South Africa with ten relatively small populations distributed in 5 provinces; Limpopo, Mpumalanga, KwaZulu-Natal, Free State and Eastern Cape Province. Crataegus monogyna was found not to be widespread in South Africa, with only three populations found in the Eastern Cape Province. Insect pollinators contribute to the fruiting of both species in SA. However, the exotic plants were also observed to be able to self-pollinate when insects are excluded. Flowers of C. monogyna were visited by various insect species from orders Lepidoptera, Hymenoptera, Coleoptera and Diptera, while C. mexicana is visited by species from the order Hymenoptera, Diptera, Lepidoptera and Coleoptera. Seventy-seven percent (77 percent) of potential dispersal vectors observed for C. monogyna were birds, and 15 percent were mammals. For C. mexicana, 71 percent of potential dispersal vectors observed were mammals, and 29 percent were birds. Crataegus monogyna and C. mexicana are emerging invasive alien species in South Africa, and not much is known about them. Although the two species are listed as invasive weeds in South Africa, very little is known about their invasive status in other parts of the world. This study has managed to give baseline information and data about both species which are already in South Africa. The baseline information and data include the population structure of both species, their distribution, the risk they pose to South Africa biodiversity and their reproduction ecology. Currently, there are no management plans in place for both species in South Africa, and this is because they are not listed yet in the National Environmental Management Biodiversity Act of South Africa. However, this study recommends that current populations continue to be monitored, awareness of both species in various provinces be initiated to help in the discovery of new and emerging populations, and management options of large populations developed in the future. , Thesis (MSc) (Entomology) -- University of Fort Hare, 2021
- Full Text:
- Date Issued: 2021-03
Baseline description of the Benthic Biotopes for two Long-Term Ecological Research (LTER) stations in Algoa Bay, Agulhas ecoregion, South Africa
- Authors: Parker-Nance, Shirley
- Date: 2021-10-29
- Subjects: Benthic ecology South Africa Algoa Bay , Long-Term Ecological Research Program , Marine invertebrates South Africa Algoa Bay , Reef ecology South Africa Algoa Bay , Coastal zone management South Africa Algoa Bay , Reef fishes South Africa Algoa Bay , Ecological mapping South Africa Algoa Bay
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/191680 , vital:45147 , 10.21504/10962/191680
- Description: Shallow coastal marine ecosystems provide important resources to society but are increasingly under threat from anthropogenic impacts. These systems form an interface between land and sea, providing valuable resources. Global environmental change, overexploitation, habitat transformation, pollution and policies aimed at short-term socio-economic gains are driving the loss of natural resources, productivity and biodiversity. Consequently, a comprehensive and holistic understanding of the current and future states of marine ecosystems is essential. This requires insight into the processes involved in maintaining genetic, species, habitat, community and biotope diversity at an ecosystem level. An understanding of ecosystem processes and the ability to detect changes in biodiversity, biotopes, seascape composition and ecosystem functioning require observation made over time and space. In response to this need, Long-Term Ecological Research (LTER) programmes such as those established by the South African Environmental Observation Network (SAEON) supported by the Department of Science and Innovation’s (DSI) Shallow Marine and Coastal Research Infrastructure (SMCRI) collect long–term observational data from different environments and systems. This study aimed to evaluate data collected as part of the developmental phase of a newly established benthic research platform. The datasets constructed are used to develop a baseline description of the benthic biotopes of two study areas within Algoa Bay. It aimed to gain insight into the feasibility of the methods used and the value of the data and derived essential biological variables (EVB). Assessing the sustainability of the programme over time was done through a practical evaluation of the methodology to be used and the technical feasibility of data collection and analysis. It furthermore aimed to assess the data usefulness in describing biodiversity at various scales and its sensitivity in reporting change. This pilot study provides valuable insight into data collection methodologies and introduces new sampling platforms. The baseline dataset consisted of data collected during the first 18 months of the SAEON Benthic Ecosystem Long-Term Ecological Research (BELTER) platform in Algoa Bay, Agulhas ecoregion, Western Indian Ocean, South Africa. This comprised of the collection of images for 150 m2 of the researched benthic seascape and 306 stereo video data streams. The 77 760 point dataset allowed the identification of 12 substrate types, 7 biotopes, 44 sub-biotope units, 377 sessile and sedentary benthic species and 51 ichthyofauna species. The described habitat and benthic communities and the defined benthic biotopes allowed for the assessment of biotope heterogeneity and the construction of a provisional distribution map for the broader biotopes. This work includes a study into the infra- and supra-benthic ichthyofauna associated with the defined biotopes and investigates the role habitat and benthic communities play in the distribution of these fish 3 assemblages. Lastly, it assesses the value of morphological traits and diversity indices for describing and comparing abiotic and biotic components of observed systems within the shallow coastal marine seascape. This study shows that species composition differs significantly between biotopes with habitat type playing a key role in the composition of the benthos. Substrate type, consolidated or unconsolidated, depth and the composition of the soft sediment is the most important determining factors. The White Sands Reef station has a higher species diversity than the St Croix Island Complex station with a higher percentage cover associated with the hard substrate. The dissimilarity between biotopes and communities are generally high although similarity within the biotopes or communities was found to be relatively low. This was considered indicative of high heterogeneity within the biotopes and a patch or mosaic-like distribution of communities within the broader biotope. A fine-scale a posteriori analysis of the data collected confirmed the high heterogeneous nature of both habitat and communities within the broader biotope. The description of the abiotic and biotic variables resulted in the identification of a diverse suite of biotope subunits. The character of the biotope hinges not only on the composition of the substrate and biota present but the contribution of smaller distinct biotopes subunits, their distribution and representation within broader biotopes and the degree these are shared with other broader biotopes. The distribution of these biotope units at different scales is believed to be important in understanding inherent diversity, niche partitioning and connectivity within a highly heterogeneous seascape. Ichthyofauna associated with the broader biotopes were indicative of the substrate type. Low profile reef systems with interspaced sandy stretches supported both reef fish and those typically associated with sandy substrates. Benthic biotopes associated characteristically with higher profile reef systems and less sand or soft sediment were mainly utilized by reef-associated fish species. Substrate type, depth and seasonality were found to be important factors in the observed composition and distribution of ichthyofauna over the seascape. Although fish species were found to have a wide distribution and made use of multiple biotopes the average abundance of the species within the observed assemblages differed. Analysis of ichthyofauna species composition indicated that observed fish assemblages were homogeneous within five of the seven biotopes. Broader biotopes that were found to be significantly different between sample locations are characterised by a diverse complement of biotope subunits and are highly heterogeneous. Traits and diversity indices are important tools for assessing and comparing different systems within the seascape, both spatially and temporally. The classification of the biota into broader phylogenetic groups indicated a significant difference between biotopes. This is especially useful when detailed 4 analysis or species identification is not possible or the skill set is not available. Morphological traits included in this study informed on the physical structure of the communities present and in combination with substrate type provided insight into the three-dimensional structure of the biotope. Species diversity, abundance, density estimates and the Shannon-Weiner diversity index were found to be the most useful diversity indices characterising and comparing biotopes. This was less so for ichthyofauna. Significant differences in the number of species observed were evident only between consolidated and unconsolidated dominated substrates. Although there was no significant difference in the number of individuals observed, both the Shannon-Weiner and Simpson Diversity indices were able to highlight differences in the fish assemblages observed for the different biotopes. The data collected, although permitting a comprehensive baseline assessment of the benthic environment for two research stations within the SAEON Algoa Bay LTER Sentinel Site, is temporally limited. The ichthyofauna dataset used was small and it is understood that the addition of length-frequency analysis of observed ichthyofauna will benefit our understanding of the biotope use by infra- and supra-benthic fish species over their life history within the larger seascape. Seasonal differences were evident and it is expected that datasets spanning several years, including LTER stations within different marine ecosystems types, will provide valuable insights on system dynamics in the short and long term both spatially and temporally. This study is the first attempt to evaluate the methodology developed and data collected in the South African Environmental Observation Network’s, Elwandle Coastal Node as part of the Shallow Marine and Coastal Research Infrastructure Benthic Ecosystem Long-Term Ecological Research (BELTER) platform. Newly designed and developed sample equipment and a sampling regime allowed for the collection of data on a long-term basis. The study was successful in the description of the biotope and biotope subunits for two research stations in Algoa Bay. It permitted the construction of comprehensive species lists for both benthic sessile and sedentary biota and the associated ichthyofauna. The subset of data used was successful in reporting on both spatial and temporal change. This work demonstrates that in the absence of detailed species identifications, traits may be used to describe habitat and community structure and report on abiotic and biotic biotope characteristics. This study furthermore allowed for the comparison of a comprehensive suite of diversity indices highlighting indices that may be especially useful in routine BELTER reporting. , Thesis (PhD) -- Faculty of Science, Ichthyology and Fisheries Science, 2021
- Full Text:
- Date Issued: 2021-10-29
- Authors: Parker-Nance, Shirley
- Date: 2021-10-29
- Subjects: Benthic ecology South Africa Algoa Bay , Long-Term Ecological Research Program , Marine invertebrates South Africa Algoa Bay , Reef ecology South Africa Algoa Bay , Coastal zone management South Africa Algoa Bay , Reef fishes South Africa Algoa Bay , Ecological mapping South Africa Algoa Bay
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/191680 , vital:45147 , 10.21504/10962/191680
- Description: Shallow coastal marine ecosystems provide important resources to society but are increasingly under threat from anthropogenic impacts. These systems form an interface between land and sea, providing valuable resources. Global environmental change, overexploitation, habitat transformation, pollution and policies aimed at short-term socio-economic gains are driving the loss of natural resources, productivity and biodiversity. Consequently, a comprehensive and holistic understanding of the current and future states of marine ecosystems is essential. This requires insight into the processes involved in maintaining genetic, species, habitat, community and biotope diversity at an ecosystem level. An understanding of ecosystem processes and the ability to detect changes in biodiversity, biotopes, seascape composition and ecosystem functioning require observation made over time and space. In response to this need, Long-Term Ecological Research (LTER) programmes such as those established by the South African Environmental Observation Network (SAEON) supported by the Department of Science and Innovation’s (DSI) Shallow Marine and Coastal Research Infrastructure (SMCRI) collect long–term observational data from different environments and systems. This study aimed to evaluate data collected as part of the developmental phase of a newly established benthic research platform. The datasets constructed are used to develop a baseline description of the benthic biotopes of two study areas within Algoa Bay. It aimed to gain insight into the feasibility of the methods used and the value of the data and derived essential biological variables (EVB). Assessing the sustainability of the programme over time was done through a practical evaluation of the methodology to be used and the technical feasibility of data collection and analysis. It furthermore aimed to assess the data usefulness in describing biodiversity at various scales and its sensitivity in reporting change. This pilot study provides valuable insight into data collection methodologies and introduces new sampling platforms. The baseline dataset consisted of data collected during the first 18 months of the SAEON Benthic Ecosystem Long-Term Ecological Research (BELTER) platform in Algoa Bay, Agulhas ecoregion, Western Indian Ocean, South Africa. This comprised of the collection of images for 150 m2 of the researched benthic seascape and 306 stereo video data streams. The 77 760 point dataset allowed the identification of 12 substrate types, 7 biotopes, 44 sub-biotope units, 377 sessile and sedentary benthic species and 51 ichthyofauna species. The described habitat and benthic communities and the defined benthic biotopes allowed for the assessment of biotope heterogeneity and the construction of a provisional distribution map for the broader biotopes. This work includes a study into the infra- and supra-benthic ichthyofauna associated with the defined biotopes and investigates the role habitat and benthic communities play in the distribution of these fish 3 assemblages. Lastly, it assesses the value of morphological traits and diversity indices for describing and comparing abiotic and biotic components of observed systems within the shallow coastal marine seascape. This study shows that species composition differs significantly between biotopes with habitat type playing a key role in the composition of the benthos. Substrate type, consolidated or unconsolidated, depth and the composition of the soft sediment is the most important determining factors. The White Sands Reef station has a higher species diversity than the St Croix Island Complex station with a higher percentage cover associated with the hard substrate. The dissimilarity between biotopes and communities are generally high although similarity within the biotopes or communities was found to be relatively low. This was considered indicative of high heterogeneity within the biotopes and a patch or mosaic-like distribution of communities within the broader biotope. A fine-scale a posteriori analysis of the data collected confirmed the high heterogeneous nature of both habitat and communities within the broader biotope. The description of the abiotic and biotic variables resulted in the identification of a diverse suite of biotope subunits. The character of the biotope hinges not only on the composition of the substrate and biota present but the contribution of smaller distinct biotopes subunits, their distribution and representation within broader biotopes and the degree these are shared with other broader biotopes. The distribution of these biotope units at different scales is believed to be important in understanding inherent diversity, niche partitioning and connectivity within a highly heterogeneous seascape. Ichthyofauna associated with the broader biotopes were indicative of the substrate type. Low profile reef systems with interspaced sandy stretches supported both reef fish and those typically associated with sandy substrates. Benthic biotopes associated characteristically with higher profile reef systems and less sand or soft sediment were mainly utilized by reef-associated fish species. Substrate type, depth and seasonality were found to be important factors in the observed composition and distribution of ichthyofauna over the seascape. Although fish species were found to have a wide distribution and made use of multiple biotopes the average abundance of the species within the observed assemblages differed. Analysis of ichthyofauna species composition indicated that observed fish assemblages were homogeneous within five of the seven biotopes. Broader biotopes that were found to be significantly different between sample locations are characterised by a diverse complement of biotope subunits and are highly heterogeneous. Traits and diversity indices are important tools for assessing and comparing different systems within the seascape, both spatially and temporally. The classification of the biota into broader phylogenetic groups indicated a significant difference between biotopes. This is especially useful when detailed 4 analysis or species identification is not possible or the skill set is not available. Morphological traits included in this study informed on the physical structure of the communities present and in combination with substrate type provided insight into the three-dimensional structure of the biotope. Species diversity, abundance, density estimates and the Shannon-Weiner diversity index were found to be the most useful diversity indices characterising and comparing biotopes. This was less so for ichthyofauna. Significant differences in the number of species observed were evident only between consolidated and unconsolidated dominated substrates. Although there was no significant difference in the number of individuals observed, both the Shannon-Weiner and Simpson Diversity indices were able to highlight differences in the fish assemblages observed for the different biotopes. The data collected, although permitting a comprehensive baseline assessment of the benthic environment for two research stations within the SAEON Algoa Bay LTER Sentinel Site, is temporally limited. The ichthyofauna dataset used was small and it is understood that the addition of length-frequency analysis of observed ichthyofauna will benefit our understanding of the biotope use by infra- and supra-benthic fish species over their life history within the larger seascape. Seasonal differences were evident and it is expected that datasets spanning several years, including LTER stations within different marine ecosystems types, will provide valuable insights on system dynamics in the short and long term both spatially and temporally. This study is the first attempt to evaluate the methodology developed and data collected in the South African Environmental Observation Network’s, Elwandle Coastal Node as part of the Shallow Marine and Coastal Research Infrastructure Benthic Ecosystem Long-Term Ecological Research (BELTER) platform. Newly designed and developed sample equipment and a sampling regime allowed for the collection of data on a long-term basis. The study was successful in the description of the biotope and biotope subunits for two research stations in Algoa Bay. It permitted the construction of comprehensive species lists for both benthic sessile and sedentary biota and the associated ichthyofauna. The subset of data used was successful in reporting on both spatial and temporal change. This work demonstrates that in the absence of detailed species identifications, traits may be used to describe habitat and community structure and report on abiotic and biotic biotope characteristics. This study furthermore allowed for the comparison of a comprehensive suite of diversity indices highlighting indices that may be especially useful in routine BELTER reporting. , Thesis (PhD) -- Faculty of Science, Ichthyology and Fisheries Science, 2021
- Full Text:
- Date Issued: 2021-10-29
Biton’s Lost Siege Engine: Experimental archaeology in Classical Studies
- Authors: Rademan, David John
- Date: 2021-10-29
- Subjects: Pergamum (Extinct city) , Dimensional analysis , Engineering History To 168 B.C. , Fluid mechanics History To 168 B.C. , Byzantine literature History and criticism , Siege warfare History To 168 B.C. , Biton of Pergamon , Isidorus of Abydos , Poliorcetics
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/192330 , vital:45216
- Description: This thesis entails an examination of several problems inherent in placing a technical treatise by the Hellenistic Greek engineer, Biton of Pergamon, at a siege of 156-154BCE, with a view to galvanising the existing case of previous scholarship through a combined approach of literary, textual, geographical, and technical analysis. Particular focus is given to the following problems: technical errors in current translations of the treatise of Biton; technical considerations in scholars’ reproductions of a particular engine in the treatise; an assessment of the practical implications of the treatise in situ at the physical site of the ancient city of Pergamon in the second century BCE, as evidenced by archaeological findings and surveys; assessment of those implications by way of historical records of similar conflicts from the Hellenistic period; and suggesting a procedure of dimensional analysis for testing a hypothesis regarding the feasibility of the ancient engineer’s recommended engines as a stand-in for the city’s original defenses, in a manner that harmonises the methodologies of historicism and experimental archaeology with sound and appropriate modern engineering practice from the field of Fluid Mechanics. , Thesis (MA) -- Faculty of Humanities, School of Languages and Literatures, 2021
- Full Text:
- Date Issued: 2021-10-29
- Authors: Rademan, David John
- Date: 2021-10-29
- Subjects: Pergamum (Extinct city) , Dimensional analysis , Engineering History To 168 B.C. , Fluid mechanics History To 168 B.C. , Byzantine literature History and criticism , Siege warfare History To 168 B.C. , Biton of Pergamon , Isidorus of Abydos , Poliorcetics
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/192330 , vital:45216
- Description: This thesis entails an examination of several problems inherent in placing a technical treatise by the Hellenistic Greek engineer, Biton of Pergamon, at a siege of 156-154BCE, with a view to galvanising the existing case of previous scholarship through a combined approach of literary, textual, geographical, and technical analysis. Particular focus is given to the following problems: technical errors in current translations of the treatise of Biton; technical considerations in scholars’ reproductions of a particular engine in the treatise; an assessment of the practical implications of the treatise in situ at the physical site of the ancient city of Pergamon in the second century BCE, as evidenced by archaeological findings and surveys; assessment of those implications by way of historical records of similar conflicts from the Hellenistic period; and suggesting a procedure of dimensional analysis for testing a hypothesis regarding the feasibility of the ancient engineer’s recommended engines as a stand-in for the city’s original defenses, in a manner that harmonises the methodologies of historicism and experimental archaeology with sound and appropriate modern engineering practice from the field of Fluid Mechanics. , Thesis (MA) -- Faculty of Humanities, School of Languages and Literatures, 2021
- Full Text:
- Date Issued: 2021-10-29
Building the field component of a smart irrigation system: A detailed experience of a computer science graduate
- Authors: Pipile, Yamnkelani Yonela
- Date: 2021-10
- Subjects: Irrigation efficiency Computer-aided design South Africa , Irrigation projects Computer-aided design South Africa , Internet of things , Machine-to-machine communications , Smart water grids South Africa , Raspberry Pi (Computer) , Arduino (Programmable controller) , ZigBee , MQTT (MQ Telemetry Transport) , MQTT-SN , XBee
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/191814 , vital:45167
- Description: South Africa is a semi-arid area with an average annual rainfall of approximately 450mm, 60 per cent of which goes towards irrigation. Current irrigation systems generally apply water in a uniform manner across a field, which is both inefficient and can kill the plants. The Internet of Things (IoT), an emerging technology involving the utilization of sensors and actuators to build complex feedback systems, present an opportunity to build a smart irrigation solution. This research project illustrates the development of the field components of a water monitoring system using off the shelf and inexpensive components, exploring at the same time how easy or difficult it would be for a general Computer Science graduate to use hardware components and associated tools within the IoT area. The problem was initially broken down through a classical top-down process, in order to identify the components such as micro-computers, micro- controllers, sensors and network connections, that would be needed to build the solution. I then selected the Raspberry Pi 3, the Arduino Arduino Uno, the MH-Sensor-Series hygrometer, the MQTT messaging protocol, and the ZigBee communication protocol as implemented in the XBee S2C. Once the components were identified, the work followed a bottom-up approach: I studied the components in isolation and relative to each other, through a structured series of experiments, with each experiment addressing a specific component and examining how easy was to use the component. While each experiment allowed the author to acquire and deepen her understanding of each component, and progressively built a more sophisticated prototype, towards the complete solution. I found the vast majority of the identified components and tools to be easy to use, well documented, and most importantly, mature for consumption by our target user, until I encountered the MQTT-SN (MQTT-Sensor Network) implementation, not as mature as the rest. This resulted in us designing and implementing a light-weight, general ZigBee/MQTT gateway, named “yoGa” (Yonella's Gateway) from the author. At the end of the research, I was able to build the field components of a smart irrigation system using the selected tools, including the yoGa gateway, proving practically that a Computer Science graduate from a South African University can become productive in the emerging IoT area. , Thesis (MSc) -- Faculty of Science, Computer Science, 2021
- Full Text:
- Date Issued: 2021-10
- Authors: Pipile, Yamnkelani Yonela
- Date: 2021-10
- Subjects: Irrigation efficiency Computer-aided design South Africa , Irrigation projects Computer-aided design South Africa , Internet of things , Machine-to-machine communications , Smart water grids South Africa , Raspberry Pi (Computer) , Arduino (Programmable controller) , ZigBee , MQTT (MQ Telemetry Transport) , MQTT-SN , XBee
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/191814 , vital:45167
- Description: South Africa is a semi-arid area with an average annual rainfall of approximately 450mm, 60 per cent of which goes towards irrigation. Current irrigation systems generally apply water in a uniform manner across a field, which is both inefficient and can kill the plants. The Internet of Things (IoT), an emerging technology involving the utilization of sensors and actuators to build complex feedback systems, present an opportunity to build a smart irrigation solution. This research project illustrates the development of the field components of a water monitoring system using off the shelf and inexpensive components, exploring at the same time how easy or difficult it would be for a general Computer Science graduate to use hardware components and associated tools within the IoT area. The problem was initially broken down through a classical top-down process, in order to identify the components such as micro-computers, micro- controllers, sensors and network connections, that would be needed to build the solution. I then selected the Raspberry Pi 3, the Arduino Arduino Uno, the MH-Sensor-Series hygrometer, the MQTT messaging protocol, and the ZigBee communication protocol as implemented in the XBee S2C. Once the components were identified, the work followed a bottom-up approach: I studied the components in isolation and relative to each other, through a structured series of experiments, with each experiment addressing a specific component and examining how easy was to use the component. While each experiment allowed the author to acquire and deepen her understanding of each component, and progressively built a more sophisticated prototype, towards the complete solution. I found the vast majority of the identified components and tools to be easy to use, well documented, and most importantly, mature for consumption by our target user, until I encountered the MQTT-SN (MQTT-Sensor Network) implementation, not as mature as the rest. This resulted in us designing and implementing a light-weight, general ZigBee/MQTT gateway, named “yoGa” (Yonella's Gateway) from the author. At the end of the research, I was able to build the field components of a smart irrigation system using the selected tools, including the yoGa gateway, proving practically that a Computer Science graduate from a South African University can become productive in the emerging IoT area. , Thesis (MSc) -- Faculty of Science, Computer Science, 2021
- Full Text:
- Date Issued: 2021-10