A proposed framework for the development of urban agriculture in South African cities
- Authors: Brown, Nicola Jayne
- Date: 2021-04
- Subjects: Urban agriculture -- South Africa , Sustainable development -- South Africa , Food security -- Climatic factors -- South Africa , Resilience (Ecology)
- Language: English
- Type: text , Thesis , Masters , MBA
- Identifier: http://hdl.handle.net/10962/174413 , vital:42475
- Description: While climate change and rapid urbanisation are impacting our cities and existing infrastructure, population growth and resource scarcity are placing unprecedented pressure on our food systems. In light of such challenges and the Sustainable Development Goals, resilient solutions are being sought to move both urban development and food production towards a more sustainable future. In this context, Urban Agriculture (UA) has been identified as a possible mechanism to complement rural food production with many associated social, economic and environmental benefits for urban communities. Some of these benefits include increased food system resilience, better urban environmental management, circular and productive reuse of urban wastes, employment opportunities, reduced food miles and the promotion of social inclusivity. Through a sustainable food system lens and underpinned by Resilience Theory, this research study sets out to investigate and explore the considerations for UA development. The research study reviews UA literature to identify and analyse the common challenges which act as barriers to implementation, as well as the current or potential opportunities which could be leveraged to drive UA development. The insights gained from literature on UA and UA development frameworks; and the data gathered from qualitative interviews with experts working in UA-related fields in South Africa (SA), were used to build a conceptual framework for UA development in SA. The conceptual framework developed is intended to be used as a guide for local municipalities, urban planners, urban farmers, urban communities and UA support organisations in their approach to developing UA initiatives. The findings from this research study reveal that UA development in SA involves numerous actors at both provincial and municipal levels; and within private institutions, businesses, universities, farmer organisations and society. The findings also reveal that UA currently occurs at many levels in SA, with each level drawing a particular range of participants due to the various social, economic and/or environmental features of the initiative. Along with challenges associated with land access, the lack of UA-related knowledge, the threat of theft, vandalism and soil contamination (to name a few); a lack of understanding of how agriculture can fit into urban spaces was found to be a major obstacle. The findings suggest that this lack of understanding has led to an under-realisation of the full potential of UA in South African towns and cities; and an inability to incentivise and optimise the development of UA. Considering the findings derived from the investigation, the study proposes five major considerations for UA development in SA, all of which are unpacked in the conceptual framework. The study concludes by making recommendations for UA decision-makers and UA organisations to consider for future developments.
- Full Text:
- Date Issued: 2021-04
- Authors: Brown, Nicola Jayne
- Date: 2021-04
- Subjects: Urban agriculture -- South Africa , Sustainable development -- South Africa , Food security -- Climatic factors -- South Africa , Resilience (Ecology)
- Language: English
- Type: text , Thesis , Masters , MBA
- Identifier: http://hdl.handle.net/10962/174413 , vital:42475
- Description: While climate change and rapid urbanisation are impacting our cities and existing infrastructure, population growth and resource scarcity are placing unprecedented pressure on our food systems. In light of such challenges and the Sustainable Development Goals, resilient solutions are being sought to move both urban development and food production towards a more sustainable future. In this context, Urban Agriculture (UA) has been identified as a possible mechanism to complement rural food production with many associated social, economic and environmental benefits for urban communities. Some of these benefits include increased food system resilience, better urban environmental management, circular and productive reuse of urban wastes, employment opportunities, reduced food miles and the promotion of social inclusivity. Through a sustainable food system lens and underpinned by Resilience Theory, this research study sets out to investigate and explore the considerations for UA development. The research study reviews UA literature to identify and analyse the common challenges which act as barriers to implementation, as well as the current or potential opportunities which could be leveraged to drive UA development. The insights gained from literature on UA and UA development frameworks; and the data gathered from qualitative interviews with experts working in UA-related fields in South Africa (SA), were used to build a conceptual framework for UA development in SA. The conceptual framework developed is intended to be used as a guide for local municipalities, urban planners, urban farmers, urban communities and UA support organisations in their approach to developing UA initiatives. The findings from this research study reveal that UA development in SA involves numerous actors at both provincial and municipal levels; and within private institutions, businesses, universities, farmer organisations and society. The findings also reveal that UA currently occurs at many levels in SA, with each level drawing a particular range of participants due to the various social, economic and/or environmental features of the initiative. Along with challenges associated with land access, the lack of UA-related knowledge, the threat of theft, vandalism and soil contamination (to name a few); a lack of understanding of how agriculture can fit into urban spaces was found to be a major obstacle. The findings suggest that this lack of understanding has led to an under-realisation of the full potential of UA in South African towns and cities; and an inability to incentivise and optimise the development of UA. Considering the findings derived from the investigation, the study proposes five major considerations for UA development in SA, all of which are unpacked in the conceptual framework. The study concludes by making recommendations for UA decision-makers and UA organisations to consider for future developments.
- Full Text:
- Date Issued: 2021-04
An exploration of working with grade 11 life sciences educators on the use of Virtual Lab to mediate learning of energy transformations
- Authors: Shambare, Brian
- Date: 2021-04
- Subjects: Life sciences -- Study and teaching (Secondary) -- South Africa -- Eastern Cape , Energy conversion -- Study and teaching , Educational technology -- South Africa -- Eastern Cape , Teaching -- Aids and devices , Virtual Lab
- Language: English
- Type: text , Thesis , Masters , MEd
- Identifier: http://hdl.handle.net/10962/174388 , vital:42473
- Description: The Department of Basic Education (DBE) examiners’ diagnostic reports for 2012-2019 indicate that National Senior Certificate (NSC) learners mostly perform poorly in examination questions based on scientific investigations. The low performance by learners in these questions has been attributed to the failure by teachers to effectively mediate the learning of scientific concepts due to lack of science laboratories or poorly resourced laboratories in most rural schools. As a result, most learners are finding that scientific concepts are decontextualized and hence abstract. Thus, this study explored making use of Virtual Lab to mediate learning of scientific investigations using the topic Energy transformations. The study was located within an interpretive paradigm and a qualitative case study approach was employed. The study was conducted in four different rural schools in the Joe Gqabi district and seven Grade 11 Life Sciences teachers participated. Data was generated using semi-structured questionnaires, semi-structured interviews, lesson observation, workshop discussions, and journal reflections. The study was informed by Vygotsky’s (1978) Socio-Cultural Theory (SCT) as the theoretical framework, and Thompson and Mishra’s (2006) Technological Pedagogical Content Knowledge (TPACK) as the analytical framework. The results of this study showed that most educators have a positive predisposition towards the integration of Information and Communication Technologies (ICT) in their practice. The study found that using the Virtual Lab to teach Life Sciences has several benefits such as safe environment for conducting experiments; convenience and accessibility; positive teacher and learner attitudes and improvement on learner performance; elimination of physical limitations of a real lab; and availability top-class lab equipment and up-to-date reagents. The study also revealed some shortcomings that were associated with the use of the Virtual Lab. These are; lack of lab partner and peer-learning; and lack of direct supervision by a more knowledgeable facilitator. This study concluded that using the Virtual Lab enhances the quality of teaching scientific experiments in the selected under-resourced rural secondary schools. The study recommends the adoption of the Virtual Lab as a viable alternative to the conventional lab.
- Full Text:
- Date Issued: 2021-04
- Authors: Shambare, Brian
- Date: 2021-04
- Subjects: Life sciences -- Study and teaching (Secondary) -- South Africa -- Eastern Cape , Energy conversion -- Study and teaching , Educational technology -- South Africa -- Eastern Cape , Teaching -- Aids and devices , Virtual Lab
- Language: English
- Type: text , Thesis , Masters , MEd
- Identifier: http://hdl.handle.net/10962/174388 , vital:42473
- Description: The Department of Basic Education (DBE) examiners’ diagnostic reports for 2012-2019 indicate that National Senior Certificate (NSC) learners mostly perform poorly in examination questions based on scientific investigations. The low performance by learners in these questions has been attributed to the failure by teachers to effectively mediate the learning of scientific concepts due to lack of science laboratories or poorly resourced laboratories in most rural schools. As a result, most learners are finding that scientific concepts are decontextualized and hence abstract. Thus, this study explored making use of Virtual Lab to mediate learning of scientific investigations using the topic Energy transformations. The study was located within an interpretive paradigm and a qualitative case study approach was employed. The study was conducted in four different rural schools in the Joe Gqabi district and seven Grade 11 Life Sciences teachers participated. Data was generated using semi-structured questionnaires, semi-structured interviews, lesson observation, workshop discussions, and journal reflections. The study was informed by Vygotsky’s (1978) Socio-Cultural Theory (SCT) as the theoretical framework, and Thompson and Mishra’s (2006) Technological Pedagogical Content Knowledge (TPACK) as the analytical framework. The results of this study showed that most educators have a positive predisposition towards the integration of Information and Communication Technologies (ICT) in their practice. The study found that using the Virtual Lab to teach Life Sciences has several benefits such as safe environment for conducting experiments; convenience and accessibility; positive teacher and learner attitudes and improvement on learner performance; elimination of physical limitations of a real lab; and availability top-class lab equipment and up-to-date reagents. The study also revealed some shortcomings that were associated with the use of the Virtual Lab. These are; lack of lab partner and peer-learning; and lack of direct supervision by a more knowledgeable facilitator. This study concluded that using the Virtual Lab enhances the quality of teaching scientific experiments in the selected under-resourced rural secondary schools. The study recommends the adoption of the Virtual Lab as a viable alternative to the conventional lab.
- Full Text:
- Date Issued: 2021-04
Economic impact of climate change on maize production in the Free State Province, South Africa
- Authors: Johnson, Richard Cowper
- Date: 2021-04
- Subjects: Corn -- Climatic factors -- South Africa -- Free State , Climatic changes -- Economic aspects -- South Africa -- Free State , Climate change mitigation -- South Africa -- Free State , Agriculture -- Economic aspects -- South Africa -- Free State
- Language: English
- Type: text , Thesis , Masters , MCom
- Identifier: http://hdl.handle.net/10962/174365 , vital:42471
- Description: Higher concentrations of CO2 in the atmosphere is a major influence on climate change globally. Climate change is caused by greenhouse gases trapping too much heat from the sun in the atmosphere and thus, altering the climate through a rise in global surface temperatures and changing precipitation patterns. CO2 is the most prominent greenhouse gas found in the atmosphere and it is reported that by the turn of the century the CO2 concentration levels will have doubled if the current rate of emissions continues. However, the increase in atmospheric levels of the gas has been found to increase the capacity of maize plants and their water use efficiency to achieve higher yields through CO2 fertilisation. Simulation experiments conducted by the Rhodes University Botany Department found that the effect of elevated levels of CO2 of double the current concentration offsets the negative effects of drought on maize. A case study was conducted on commercial maize farmers in two regions of the Free State province in South Africa to estimate the economic impact of climate change on maize production. Although production is increasing in the province, adaptation to the changing climate is key to the sustainability of production. There is a trade-off between the negative effects of higher CO2 levels changing the climate and the positive effect of CO2 fertilisation. As predicted, the economic impact of climate change is the disruption of farming practices and the increase in costs of production as a result of adapting to climate change. Using a gross margin analysis, the study found that the larger maize farmers who benefit from economies of scale are able to adapt and grow their production whilst the smaller farmers are being pushed out of the market.
- Full Text:
- Date Issued: 2021-04
- Authors: Johnson, Richard Cowper
- Date: 2021-04
- Subjects: Corn -- Climatic factors -- South Africa -- Free State , Climatic changes -- Economic aspects -- South Africa -- Free State , Climate change mitigation -- South Africa -- Free State , Agriculture -- Economic aspects -- South Africa -- Free State
- Language: English
- Type: text , Thesis , Masters , MCom
- Identifier: http://hdl.handle.net/10962/174365 , vital:42471
- Description: Higher concentrations of CO2 in the atmosphere is a major influence on climate change globally. Climate change is caused by greenhouse gases trapping too much heat from the sun in the atmosphere and thus, altering the climate through a rise in global surface temperatures and changing precipitation patterns. CO2 is the most prominent greenhouse gas found in the atmosphere and it is reported that by the turn of the century the CO2 concentration levels will have doubled if the current rate of emissions continues. However, the increase in atmospheric levels of the gas has been found to increase the capacity of maize plants and their water use efficiency to achieve higher yields through CO2 fertilisation. Simulation experiments conducted by the Rhodes University Botany Department found that the effect of elevated levels of CO2 of double the current concentration offsets the negative effects of drought on maize. A case study was conducted on commercial maize farmers in two regions of the Free State province in South Africa to estimate the economic impact of climate change on maize production. Although production is increasing in the province, adaptation to the changing climate is key to the sustainability of production. There is a trade-off between the negative effects of higher CO2 levels changing the climate and the positive effect of CO2 fertilisation. As predicted, the economic impact of climate change is the disruption of farming practices and the increase in costs of production as a result of adapting to climate change. Using a gross margin analysis, the study found that the larger maize farmers who benefit from economies of scale are able to adapt and grow their production whilst the smaller farmers are being pushed out of the market.
- Full Text:
- Date Issued: 2021-04
Reminiscing In Tempo : Ubangulo
- Authors: Tutani, Zodwa
- Date: 2021-04
- Subjects: Creative writing (Higher education) -- South Africa , South African poetry (English) -- 21st century , South African poetry (English) -- History and criticism , Diaries -- Authorship
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/174376 , vital:42472
- Description: My thesis is a collection of poems that focuses on black mothering and motherhood, within the context of the Eastern Cape’s violent history, its oppressive patriarchal cultural traditions and religious structures. Drawing from my own experiences, my poems explore what Toni Morrison calls the historical ‘wounds’ of black women which are transferred to their daughters within everyday spaces like the kitchen and the lounge, through objects like tea cups, chair backs and the various foods that every black girl needs to be able to prepare in order to be ‘marriagable’, and how these continue to hurt and emotionally disfigure us. I also draw influence from Saidiya Hartman, Christina Sharpe and Tina Campt on black lives and the effects of slavery within their daily existences. And I am inspired by the intimacy and care with which Tadeusz Rosewicz writes about his relationship with his mother in Mother Departs and Sandra Cisneros’ use of interconnected vignettes to engage childhood, culture and community within marginalized space. Stylistically I am influenced by the structural innovations in Fred Moten’s The Little Edges and the dreamy landscape in the poetry of Federico Garcia Lorca. My collection includes prose and lyrical poetry, combining more formal sound and rhythmic structures with free verse, to bring to life motherhood and the narratives we carry from childhood into our adult lives.
- Full Text:
- Date Issued: 2021-04
- Authors: Tutani, Zodwa
- Date: 2021-04
- Subjects: Creative writing (Higher education) -- South Africa , South African poetry (English) -- 21st century , South African poetry (English) -- History and criticism , Diaries -- Authorship
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/174376 , vital:42472
- Description: My thesis is a collection of poems that focuses on black mothering and motherhood, within the context of the Eastern Cape’s violent history, its oppressive patriarchal cultural traditions and religious structures. Drawing from my own experiences, my poems explore what Toni Morrison calls the historical ‘wounds’ of black women which are transferred to their daughters within everyday spaces like the kitchen and the lounge, through objects like tea cups, chair backs and the various foods that every black girl needs to be able to prepare in order to be ‘marriagable’, and how these continue to hurt and emotionally disfigure us. I also draw influence from Saidiya Hartman, Christina Sharpe and Tina Campt on black lives and the effects of slavery within their daily existences. And I am inspired by the intimacy and care with which Tadeusz Rosewicz writes about his relationship with his mother in Mother Departs and Sandra Cisneros’ use of interconnected vignettes to engage childhood, culture and community within marginalized space. Stylistically I am influenced by the structural innovations in Fred Moten’s The Little Edges and the dreamy landscape in the poetry of Federico Garcia Lorca. My collection includes prose and lyrical poetry, combining more formal sound and rhythmic structures with free verse, to bring to life motherhood and the narratives we carry from childhood into our adult lives.
- Full Text:
- Date Issued: 2021-04
Accelerated implementations of the RIME for DDE calibration and source modelling
- Authors: Van Staden, Joshua
- Date: 2021
- Subjects: Radio astronomy , Radio inferometers , Radio inferometers -- Calibration , Radio astronomy -- Data processing , Radio inferometers -- Data processing , Radio inferometers -- Calibration -- Data processing
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/172422 , vital:42199
- Description: Second- and third-generation calibration methods filter out subtle effects in interferometer data, and therefore yield significantly higher dynamic ranges. The basis of these calibration techniques relies on building a model of the sky and corrupting it with models of the effects acting on the sources. The sensitivities of modern instruments call for more elaborate models to capture the level of detail that is required to achieve accurate calibration. This thesis implements two types of models to be used in for second- and third-generation calibration. The first model implemented is shapelets, which can be used to model radio source morphologies directly in uv space. The second model implemented is Zernike polynomials, which can be used to represent the primary beam of the antenna. We implement these models in the CODEX-AFRICANUS package and provide a set of unit tests for each model. Additionally, we compare our implementations against other methods of representing these objects and instrumental effects, namely NIFTY-GRIDDER against shapelets and a FITS-interpolation method against the Zernike polynomials. We find that to achieve sufficient accuracy, our implementation of the shapelet model has a higher runtime to that of the NIFTY-GRIDDER. However, the NIFTY-GRIDDER cannot simulate a component-based sky model while the shapelet model can. Additionally, the shapelet model is fully parametric, which allows for integration into a parameterised solver. We find that, while having a smaller memory footprint, our Zernike model has a greater computational complexity than that of the FITS-interpolated method. However, we find that the Zernike implementation has floating-point accuracy in its modelling, while the FITS-interpolated model loses some accuracy through the discretisation of the beam.
- Full Text:
- Date Issued: 2021
- Authors: Van Staden, Joshua
- Date: 2021
- Subjects: Radio astronomy , Radio inferometers , Radio inferometers -- Calibration , Radio astronomy -- Data processing , Radio inferometers -- Data processing , Radio inferometers -- Calibration -- Data processing
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/172422 , vital:42199
- Description: Second- and third-generation calibration methods filter out subtle effects in interferometer data, and therefore yield significantly higher dynamic ranges. The basis of these calibration techniques relies on building a model of the sky and corrupting it with models of the effects acting on the sources. The sensitivities of modern instruments call for more elaborate models to capture the level of detail that is required to achieve accurate calibration. This thesis implements two types of models to be used in for second- and third-generation calibration. The first model implemented is shapelets, which can be used to model radio source morphologies directly in uv space. The second model implemented is Zernike polynomials, which can be used to represent the primary beam of the antenna. We implement these models in the CODEX-AFRICANUS package and provide a set of unit tests for each model. Additionally, we compare our implementations against other methods of representing these objects and instrumental effects, namely NIFTY-GRIDDER against shapelets and a FITS-interpolation method against the Zernike polynomials. We find that to achieve sufficient accuracy, our implementation of the shapelet model has a higher runtime to that of the NIFTY-GRIDDER. However, the NIFTY-GRIDDER cannot simulate a component-based sky model while the shapelet model can. Additionally, the shapelet model is fully parametric, which allows for integration into a parameterised solver. We find that, while having a smaller memory footprint, our Zernike model has a greater computational complexity than that of the FITS-interpolated method. However, we find that the Zernike implementation has floating-point accuracy in its modelling, while the FITS-interpolated model loses some accuracy through the discretisation of the beam.
- Full Text:
- Date Issued: 2021
An exploratory study of psychologists’ perceptions of the phenomenon currently understood as ‘borderline personality disorder’
- Authors: Daya, Lekha
- Date: 2021
- Subjects: Borderline personality disorder , Psychologists -- Attitudes -- South Africa , Diagnostic and statistical manual of mental disorders
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/171139 , vital:42023
- Description: The phenomenon currently understood as ‘borderline personality disorder’ (BPD) has been complex and multifaceted since its inception. Previous studies have focused on the validity of The Diagnostic and Statistical Manual of Mental Disorders (DSM) conceptualisation of BPD, aetiologies of BPD, the psychologies of persons diagnosed with BPD, and the gendered nature of BPD. This study aimed to specifically explore South African practising psychologists’ perceptions of BPD. Through thematic analysis from a constructivist, post-modern paradigm, this study aimed to explore the perceptions and experiences of practising psychologists on BPD, as well as the usefulness of the DSM in working with BPD in a non-western society such as South Africa (SA). The study sampled two Counselling and two Clinical psychologists practising in the South African context, with exposure to and experience in working with BPD. Collectively, results in this study identified psychologists’ perceptions of shortcomings in the usefulness of the DSM’s approach to categorising phenomena associated with BPD, and brought attention to a need for further research and attention into the role of psychologists’ in the construction of BPD. This study seeks to represent psychologists’ practical experiences and perceptions, in an attempt to add contextually relevant findings on the DSM’s construction of BPD, and to contribute to challenging the stigma and misunderstanding associated with BPD. Specific practice implications and recommendations for future research are discussed within.
- Full Text:
- Date Issued: 2021
- Authors: Daya, Lekha
- Date: 2021
- Subjects: Borderline personality disorder , Psychologists -- Attitudes -- South Africa , Diagnostic and statistical manual of mental disorders
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/171139 , vital:42023
- Description: The phenomenon currently understood as ‘borderline personality disorder’ (BPD) has been complex and multifaceted since its inception. Previous studies have focused on the validity of The Diagnostic and Statistical Manual of Mental Disorders (DSM) conceptualisation of BPD, aetiologies of BPD, the psychologies of persons diagnosed with BPD, and the gendered nature of BPD. This study aimed to specifically explore South African practising psychologists’ perceptions of BPD. Through thematic analysis from a constructivist, post-modern paradigm, this study aimed to explore the perceptions and experiences of practising psychologists on BPD, as well as the usefulness of the DSM in working with BPD in a non-western society such as South Africa (SA). The study sampled two Counselling and two Clinical psychologists practising in the South African context, with exposure to and experience in working with BPD. Collectively, results in this study identified psychologists’ perceptions of shortcomings in the usefulness of the DSM’s approach to categorising phenomena associated with BPD, and brought attention to a need for further research and attention into the role of psychologists’ in the construction of BPD. This study seeks to represent psychologists’ practical experiences and perceptions, in an attempt to add contextually relevant findings on the DSM’s construction of BPD, and to contribute to challenging the stigma and misunderstanding associated with BPD. Specific practice implications and recommendations for future research are discussed within.
- Full Text:
- Date Issued: 2021
An online information security Aaareness model: the disclosure of personal data
- Authors: Parker, Heather Joubert
- Date: 2021
- Subjects: Social media -- Psychological aspects , Social media -- Psychological aspects -- South Africa , Human behavior , Disclosure of information -- Psychological aspects -- Case studies , Personal information management -- Psychological aspects -- Case studies , Data protection -- Psychologial aspects -- Case studies
- Language: English
- Type: text , Thesis , Masters , MCom
- Identifier: http://hdl.handle.net/10962/172329 , vital:42189
- Description: Social media has revolutionized the way people send and receive information by creating a new level of interconnected communication. However, the use of the Internet and social media brings about various ways in which a user’s personal data can be put at risk. This study aims to investigate what drives the disclosure of personal information online and whether an increase in awareness of the value of personal information motivates users to safeguard their information. Fourteen university students participated in a mixed-methods experiment, where they completed a questionnaire before and after being shown the data stored about them by online platforms to determine if changes occur in their intention to disclose. Following completing the initial questionnaire, the participant viewed the personal data stored about them by Facebook, Google, and Instagram. Other online tools such as Social Profile Checker, Facebook View As, and HaveIBeenPawned were used to see the information publicly available about each participant. Together these findings were discussed in a semi-structured interview to determine the influence of attitudes, subjective norms, and awareness on the cost-benefit analysis users conduct when disclosing information online. Overall, the findings indicate that users are able to disregard their concerns due to a resigned and apathetic attitude towards privacy. Furthermore, subjective norms enhanced by FOMO further allow users to overlook potential risks to their information in order to avoid social isolation and sanction. Alternatively, an increased awareness of the personal value of information and having experienced a previous privacy violation encourage the protection of information and limited disclosure. Thus, this study provides insight into privacy and information disclosure on social media in South Africa. It reveals more insight into the cost-benefit analysis users conduct by combining the Theory of Planned Behaviour with the Privacy Calculus Model, as well as the antecedent factors of Trust in the Social Media Provider, FOMO, and Personal Valuation of Information.
- Full Text:
- Date Issued: 2021
- Authors: Parker, Heather Joubert
- Date: 2021
- Subjects: Social media -- Psychological aspects , Social media -- Psychological aspects -- South Africa , Human behavior , Disclosure of information -- Psychological aspects -- Case studies , Personal information management -- Psychological aspects -- Case studies , Data protection -- Psychologial aspects -- Case studies
- Language: English
- Type: text , Thesis , Masters , MCom
- Identifier: http://hdl.handle.net/10962/172329 , vital:42189
- Description: Social media has revolutionized the way people send and receive information by creating a new level of interconnected communication. However, the use of the Internet and social media brings about various ways in which a user’s personal data can be put at risk. This study aims to investigate what drives the disclosure of personal information online and whether an increase in awareness of the value of personal information motivates users to safeguard their information. Fourteen university students participated in a mixed-methods experiment, where they completed a questionnaire before and after being shown the data stored about them by online platforms to determine if changes occur in their intention to disclose. Following completing the initial questionnaire, the participant viewed the personal data stored about them by Facebook, Google, and Instagram. Other online tools such as Social Profile Checker, Facebook View As, and HaveIBeenPawned were used to see the information publicly available about each participant. Together these findings were discussed in a semi-structured interview to determine the influence of attitudes, subjective norms, and awareness on the cost-benefit analysis users conduct when disclosing information online. Overall, the findings indicate that users are able to disregard their concerns due to a resigned and apathetic attitude towards privacy. Furthermore, subjective norms enhanced by FOMO further allow users to overlook potential risks to their information in order to avoid social isolation and sanction. Alternatively, an increased awareness of the personal value of information and having experienced a previous privacy violation encourage the protection of information and limited disclosure. Thus, this study provides insight into privacy and information disclosure on social media in South Africa. It reveals more insight into the cost-benefit analysis users conduct by combining the Theory of Planned Behaviour with the Privacy Calculus Model, as well as the antecedent factors of Trust in the Social Media Provider, FOMO, and Personal Valuation of Information.
- Full Text:
- Date Issued: 2021
Asymmetric price transmission: an empirical analysis of the relationship between UG-2 chrome ore, charge chrome, nickel and Chinese domestic 304 stainless steel cold rolled coil
- Authors: Le Roux, Simon Petrus
- Date: 2021
- Subjects: Pricing , Chromium ores -- Prices -- South Africa , Nickel -- Prices -- South Africa , Austenitic stainless steel-- Prices -- China , Steel -- Prices -- South Africa , Non-Linear Autoregressive Distributive Lag (NARDL)
- Language: English
- Type: text , Thesis , Masters , MCom
- Identifier: http://hdl.handle.net/10962/171336 , vital:42049
- Description: The goal of this study was to determine whether asymmetric price transmission (APT) exists between the prices of South African UG-2 Chrome ore, Charge Chrome, Nickel and Chinese Domestic 304 Stainless steel Cold Rolled Coil prices. Monthly time series data for the period January 2009 to July 2019 was analysed. The Non-Linear Autoregressive Distributive Lag (NARDL) model was applied to test for the presence of price asymmetry between the four variables. Firstly, it was observed that the four variables are cointegrated in the long-run. Secondly, no evidence of price asymmetry was found to be present within the Stainless steel supply chain. The reason for this is most likely due to the extremely close-knit and highly concentrated nature of this industry at each level within the supply chain. The industry can be very opaque to external observers even though the distribution of pricing information is very efficient for participants within the industry.
- Full Text:
- Date Issued: 2021
- Authors: Le Roux, Simon Petrus
- Date: 2021
- Subjects: Pricing , Chromium ores -- Prices -- South Africa , Nickel -- Prices -- South Africa , Austenitic stainless steel-- Prices -- China , Steel -- Prices -- South Africa , Non-Linear Autoregressive Distributive Lag (NARDL)
- Language: English
- Type: text , Thesis , Masters , MCom
- Identifier: http://hdl.handle.net/10962/171336 , vital:42049
- Description: The goal of this study was to determine whether asymmetric price transmission (APT) exists between the prices of South African UG-2 Chrome ore, Charge Chrome, Nickel and Chinese Domestic 304 Stainless steel Cold Rolled Coil prices. Monthly time series data for the period January 2009 to July 2019 was analysed. The Non-Linear Autoregressive Distributive Lag (NARDL) model was applied to test for the presence of price asymmetry between the four variables. Firstly, it was observed that the four variables are cointegrated in the long-run. Secondly, no evidence of price asymmetry was found to be present within the Stainless steel supply chain. The reason for this is most likely due to the extremely close-knit and highly concentrated nature of this industry at each level within the supply chain. The industry can be very opaque to external observers even though the distribution of pricing information is very efficient for participants within the industry.
- Full Text:
- Date Issued: 2021
Development and calidation of the psychometric properties underpinning the Kwaito Music Attitude and Perception Scale (KMP)
- Authors: Williams, Akhona
- Date: 2021
- Subjects: Kwaito-music Attitude and Perception , Chronbach's alpha , Kwaito (Music) , Psychotherapy and music -- South Africa , Problem youth -- Rehabilitation -- South Africa , Attitude (Psychology) -- Testing -- South Africa , Perception -- Testing -- South Africa
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/172478 , vital:42208
- Description: Music holds a privileged position in enhancing therapeutic well-being, supporting life skills development in youth and adolescents, and shaping cultural identities. As such, music has been closely related to youth culture, especially as it pertains to youth rehabilitation and identity formation. Studies (e.g., Duffy and Fuller, 2000; Miranda et al, 2013; Strayhorn, 2011; Tomasello, 2016) highlight the value of utilising music in youth rehabilitation, and acknowledge the intrinsic value of music to facilitate psychological and social change for individuals who would not otherwise benefit from psycho-education, or other didactic modes of youth rehabilitation. That said, Tyson (2005) developed the RAP music scale to psychometrically validate the underlying constructs of youth’ attitudes and perception of rap music in the United States of America, in order to use the instrument for music-based youth rehabilitation programs. The development of the RAP music scale informed the creation and validation of the Kwaito-music Attitude and Perception (KMP) Scale, the subject of my Masters thesis. Following suggestions from Morrison (2014), my study sought to psychometrically validate the properties of the Kwaito-music Attitude and Perception (KMP) Scale. The KMP was found to be a reliable measure of kwaito music attitudes and perception amongst a sample of South African youth who listen to this genre of music. The internal consistency of the questionnaire revealed a Cronbach’s α (Alpha) value of 0.820. Limitations of the project including reduced factor extraction and sample size constrains are discussed. It is envisioned that results from this study will find resonance with youth-community programs, and rehabilitation projects utilising music as a medium of healing amongst South African youth.
- Full Text:
- Date Issued: 2021
- Authors: Williams, Akhona
- Date: 2021
- Subjects: Kwaito-music Attitude and Perception , Chronbach's alpha , Kwaito (Music) , Psychotherapy and music -- South Africa , Problem youth -- Rehabilitation -- South Africa , Attitude (Psychology) -- Testing -- South Africa , Perception -- Testing -- South Africa
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/172478 , vital:42208
- Description: Music holds a privileged position in enhancing therapeutic well-being, supporting life skills development in youth and adolescents, and shaping cultural identities. As such, music has been closely related to youth culture, especially as it pertains to youth rehabilitation and identity formation. Studies (e.g., Duffy and Fuller, 2000; Miranda et al, 2013; Strayhorn, 2011; Tomasello, 2016) highlight the value of utilising music in youth rehabilitation, and acknowledge the intrinsic value of music to facilitate psychological and social change for individuals who would not otherwise benefit from psycho-education, or other didactic modes of youth rehabilitation. That said, Tyson (2005) developed the RAP music scale to psychometrically validate the underlying constructs of youth’ attitudes and perception of rap music in the United States of America, in order to use the instrument for music-based youth rehabilitation programs. The development of the RAP music scale informed the creation and validation of the Kwaito-music Attitude and Perception (KMP) Scale, the subject of my Masters thesis. Following suggestions from Morrison (2014), my study sought to psychometrically validate the properties of the Kwaito-music Attitude and Perception (KMP) Scale. The KMP was found to be a reliable measure of kwaito music attitudes and perception amongst a sample of South African youth who listen to this genre of music. The internal consistency of the questionnaire revealed a Cronbach’s α (Alpha) value of 0.820. Limitations of the project including reduced factor extraction and sample size constrains are discussed. It is envisioned that results from this study will find resonance with youth-community programs, and rehabilitation projects utilising music as a medium of healing amongst South African youth.
- Full Text:
- Date Issued: 2021
Evaluating the cyber security skills gap relating to penetration testing
- Authors: Beukes, Dirk Johannes
- Date: 2021
- Subjects: Computer networks -- Security measures , Computer networks -- Monitoring , Computer networks -- Management , Data protection , Information technology -- Security measures , Professionals -- Supply and demand , Electronic data personnel -- Supply and demand
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/171120 , vital:42021
- Description: Information Technology (IT) is growing rapidly and has become an integral part of daily life. It provides a boundless list of services and opportunities, generating boundless sources of information, which could be abused or exploited. Due to this growth, there are thousands of new users added to the grid using computer systems in a static and mobile environment; this fact alone creates endless volumes of data to be exploited and hardware devices to be abused by the wrong people. The growth in the IT environment adds challenges that may affect users in their personal, professional, and business lives. There are constant threats on corporate and private computer networks and computer systems. In the corporate environment companies try to eliminate the threat by testing networks making use of penetration tests and by implementing cyber awareness programs to make employees more aware of the cyber threat. Penetration tests and vulnerability assessments are undervalued; are seen as a formality and are not used to increase system security. If used regularly the computer system will be more secure and attacks minimized. With the growth in technology, industries all over the globe become fully dependent on information systems in doing their day-to-day business. As technology evolves and new technology becomes available, the bigger the risk becomes to protect against the dangers which come with this new technology. For industry to protect itself against this growth in technology, personnel with a certain skill set is needed. This is where cyber security plays a very important role in the protection of information systems to ensure the confidentiality, integrity and availability of the information system itself and the data on the system. Due to this drive to secure information systems, the need for cyber security by professionals is on the rise as well. It is estimated that there is a shortage of one million cyber security professionals globally. What is the reason for this skills shortage? Will it be possible to close this skills shortage gap? This study is about identifying the skills gap and identifying possible ways to close this skills gap. In this study, research was conducted on the cyber security international standards, cyber security training at universities and international certification focusing specifically on penetration testing, the evaluation of the need of industry while recruiting new penetration testers, finishing with suggestions on how to fill possible gaps in the skills market with a conclusion.
- Full Text:
- Date Issued: 2021
- Authors: Beukes, Dirk Johannes
- Date: 2021
- Subjects: Computer networks -- Security measures , Computer networks -- Monitoring , Computer networks -- Management , Data protection , Information technology -- Security measures , Professionals -- Supply and demand , Electronic data personnel -- Supply and demand
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/171120 , vital:42021
- Description: Information Technology (IT) is growing rapidly and has become an integral part of daily life. It provides a boundless list of services and opportunities, generating boundless sources of information, which could be abused or exploited. Due to this growth, there are thousands of new users added to the grid using computer systems in a static and mobile environment; this fact alone creates endless volumes of data to be exploited and hardware devices to be abused by the wrong people. The growth in the IT environment adds challenges that may affect users in their personal, professional, and business lives. There are constant threats on corporate and private computer networks and computer systems. In the corporate environment companies try to eliminate the threat by testing networks making use of penetration tests and by implementing cyber awareness programs to make employees more aware of the cyber threat. Penetration tests and vulnerability assessments are undervalued; are seen as a formality and are not used to increase system security. If used regularly the computer system will be more secure and attacks minimized. With the growth in technology, industries all over the globe become fully dependent on information systems in doing their day-to-day business. As technology evolves and new technology becomes available, the bigger the risk becomes to protect against the dangers which come with this new technology. For industry to protect itself against this growth in technology, personnel with a certain skill set is needed. This is where cyber security plays a very important role in the protection of information systems to ensure the confidentiality, integrity and availability of the information system itself and the data on the system. Due to this drive to secure information systems, the need for cyber security by professionals is on the rise as well. It is estimated that there is a shortage of one million cyber security professionals globally. What is the reason for this skills shortage? Will it be possible to close this skills shortage gap? This study is about identifying the skills gap and identifying possible ways to close this skills gap. In this study, research was conducted on the cyber security international standards, cyber security training at universities and international certification focusing specifically on penetration testing, the evaluation of the need of industry while recruiting new penetration testers, finishing with suggestions on how to fill possible gaps in the skills market with a conclusion.
- Full Text:
- Date Issued: 2021
Exploring domestic workers’ subjectivities through stories of their personal childcare arrangements
- Authors: Michaeu, Nisha
- Date: 2021
- Subjects: Women household employees, Black -- Social conditions -- South Africa , Women household employees, Black -- Social conditions -- South Africa -- Case studies , Women household employees, Black -- Psychology -- South Africa , Day care aides -- South Africa
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/172029 , vital:42150
- Description: Domestic service has long been a major sector of the South African labour market, for black women particularly, who must support their family and children. Existing research has stressed the way in which race, class and gender has shaped the oppressive character of domestic service in South Africa. In this narrative study a new slant is provided on this existing theoretical discussion of domestic labour, one that is focused on exploring the agentic human being beyond ‘the servant question’. This study uses narrative interviews with domestic workers in Makhanda/Grahamstown in the Eastern Cape province of South Africa to show how we can expand on potentially limited or constricted passive ‘domestic worker identities’ and ideas/beliefs about women who do domestic work. A performative and positioning narrative analysis is used to explore the subject positions of domestic workers in their stories about their childcare arrangements. This analysis examines multiple shifting identities and positions that are used by domestic workers in relation to their maternal subjectivity and their audience (here, a white trainee-psychologist esearcher), while highlighting the significance of narrative methodology in making these positions visible. The areas of focus were their history, experience of domestic work, life outside of domestic work, family network/dynamics and personal childcare arrangements. Under these areas of focus the following was analysed: the ways in which the storyteller positioned herself in her narrative, how she compared/contrasted or located herself in relation to the other, claims of identity that were made, what she incorporated or purposefully left out, words and phrases that were chosen, which sections of talk were embellished or elaborated on and appeals that were made to the interviewer (Riessman, 2002). Through exploring the micro-practices of domestic workers’ lives the study found that there were various subject positions constructed and used by this group of women. Findings showed that domestic workers positioned themselves actively as breadwinners, good mothers who give their children opportunities that they were not given, nurturers and crafty mothers who secure good care for their children. In contrast to these active subject positions, positions of sacrifice were performed when domestic workers spoke about leaving their young children in the care of another while they worked. The study also found that participants managed complex positions of disappointment and unmet expectations for a better life in the new South Africa by using narratives of resistance and agency. In certain instances, identity appeals were made to the interviewer that they, and other women who do domestic work, are entrepreneurial and creative with their income and possess skills outside of their day-to-day household cleaning jobs. This was interpreted as an attempt to extend the domestic worker identity positioning beyond the traditionally accepted notions of unskilled/uneducated women who do domestic work. In the study this allowed for more subject positions to be taken up in terms of identities and selves, beyond just being a “domestic worker”.
- Full Text:
- Date Issued: 2021
- Authors: Michaeu, Nisha
- Date: 2021
- Subjects: Women household employees, Black -- Social conditions -- South Africa , Women household employees, Black -- Social conditions -- South Africa -- Case studies , Women household employees, Black -- Psychology -- South Africa , Day care aides -- South Africa
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/172029 , vital:42150
- Description: Domestic service has long been a major sector of the South African labour market, for black women particularly, who must support their family and children. Existing research has stressed the way in which race, class and gender has shaped the oppressive character of domestic service in South Africa. In this narrative study a new slant is provided on this existing theoretical discussion of domestic labour, one that is focused on exploring the agentic human being beyond ‘the servant question’. This study uses narrative interviews with domestic workers in Makhanda/Grahamstown in the Eastern Cape province of South Africa to show how we can expand on potentially limited or constricted passive ‘domestic worker identities’ and ideas/beliefs about women who do domestic work. A performative and positioning narrative analysis is used to explore the subject positions of domestic workers in their stories about their childcare arrangements. This analysis examines multiple shifting identities and positions that are used by domestic workers in relation to their maternal subjectivity and their audience (here, a white trainee-psychologist esearcher), while highlighting the significance of narrative methodology in making these positions visible. The areas of focus were their history, experience of domestic work, life outside of domestic work, family network/dynamics and personal childcare arrangements. Under these areas of focus the following was analysed: the ways in which the storyteller positioned herself in her narrative, how she compared/contrasted or located herself in relation to the other, claims of identity that were made, what she incorporated or purposefully left out, words and phrases that were chosen, which sections of talk were embellished or elaborated on and appeals that were made to the interviewer (Riessman, 2002). Through exploring the micro-practices of domestic workers’ lives the study found that there were various subject positions constructed and used by this group of women. Findings showed that domestic workers positioned themselves actively as breadwinners, good mothers who give their children opportunities that they were not given, nurturers and crafty mothers who secure good care for their children. In contrast to these active subject positions, positions of sacrifice were performed when domestic workers spoke about leaving their young children in the care of another while they worked. The study also found that participants managed complex positions of disappointment and unmet expectations for a better life in the new South Africa by using narratives of resistance and agency. In certain instances, identity appeals were made to the interviewer that they, and other women who do domestic work, are entrepreneurial and creative with their income and possess skills outside of their day-to-day household cleaning jobs. This was interpreted as an attempt to extend the domestic worker identity positioning beyond the traditionally accepted notions of unskilled/uneducated women who do domestic work. In the study this allowed for more subject positions to be taken up in terms of identities and selves, beyond just being a “domestic worker”.
- Full Text:
- Date Issued: 2021
Infant health: a community-based assessment and educational intervention in two rural communities in the Eastern Cape.
- Authors: Kuzeeko, Faith
- Date: 2021
- Subjects: Angus Gillis Foundation (South Africa) , Infants -- Mortality -- South Africa , Infants -- Health and hygiene -- South Africa , Breastfeeding -- South Africa -- Eastern Cape , Infants -- Care -- Equipment and supplies , Infants -- Care -- South Africa -- Eastern Cape -- Case studies , Children -- Mortality -- South Africa , High throughput screening (Drug development)
- Language: English
- Type: text , Thesis , Masters , MPharm
- Identifier: http://hdl.handle.net/10962/170837 , vital:41964
- Description: South Africa is on track to attaining the 2030 Agenda on reducing under-five deaths to 25 deaths per 1000 live births at its current momentum, however an unacceptable amount of infants are still at risk from preventable illnesses. Malnutrition is the major underlined cause of infant mortality rates in South Africa. Exclusive breastfeeding rates are low nationwide due to low exposure to breastfeeding information, some mothers having other commitments and others having breastfeeding difficulties. Implementation and expansion of simple, cost-effective interventions, such as exclusive breastfeeding for six months to reduce and/or prevent infant mortality rates, remains low in South Africa. The aim of the study was to determine one infant health issue of major concern to participants in two rural villages in the Eastern Cape, namely Glenmore and Ndwayana. The identified infant health issue was used to design an educational intervention in the villages. This was the second phase of this study. A community-based participatory approach was utilized in which the Angus Gillis Foundation, a non-profit organization that works in these communities, was one of the stakeholders. Stock status of WHO priority medicines for infants, semi-structured interviews and focus group discussions were carried out during the baseline study. The intervention phase contained pre-2 intervention semi-structured interviews with ten pregnant women followed by an educational intervention with nine out of the ten; and finally, a post-intervention with seven out of the ten women. A questionnaire was completed by members of the Angus Gillis Foundation to provide feedback on the sustainability of the intervention. Semi-structured interviews revealed that medicines stocked at the clinic parallel those indicated in the WHO priority medicines list for infants. The results from the focus group discussions indicated that mothers do not exclusively breastfeed their infants during the first six months. Pre- and post-intervention results on exclusive breastfeeding illustrated a positive change in participants’ knowledge and intent to breastfeed exclusively for six months. They showed a better understanding of the importance of exclusive breastfeeding and indicated a more focussed intention and confidence to carry out optimal breastfeeding practices. In the questionnaire the members of the Angus Gillis Foundation stated that the intervention is sustainable as it was linked with the existing networks. These include educational programs carried out in the villages by the foundation together with positive health champions, community health workers and women self-help groups; which will be able to build on the present knowledge base. Finally, the study also included the design of a booklet on the identified infant health issue. In conclusion, participants highlighted lack of understanding regarding breastfeeding as an issue of concern during the baseline phase of the study. This community-based educational intervention improved the understanding of breastfeeding among the participants, resulting in a positive change in perception with regards to exclusive breastfeeding practices.
- Full Text:
- Date Issued: 2021
- Authors: Kuzeeko, Faith
- Date: 2021
- Subjects: Angus Gillis Foundation (South Africa) , Infants -- Mortality -- South Africa , Infants -- Health and hygiene -- South Africa , Breastfeeding -- South Africa -- Eastern Cape , Infants -- Care -- Equipment and supplies , Infants -- Care -- South Africa -- Eastern Cape -- Case studies , Children -- Mortality -- South Africa , High throughput screening (Drug development)
- Language: English
- Type: text , Thesis , Masters , MPharm
- Identifier: http://hdl.handle.net/10962/170837 , vital:41964
- Description: South Africa is on track to attaining the 2030 Agenda on reducing under-five deaths to 25 deaths per 1000 live births at its current momentum, however an unacceptable amount of infants are still at risk from preventable illnesses. Malnutrition is the major underlined cause of infant mortality rates in South Africa. Exclusive breastfeeding rates are low nationwide due to low exposure to breastfeeding information, some mothers having other commitments and others having breastfeeding difficulties. Implementation and expansion of simple, cost-effective interventions, such as exclusive breastfeeding for six months to reduce and/or prevent infant mortality rates, remains low in South Africa. The aim of the study was to determine one infant health issue of major concern to participants in two rural villages in the Eastern Cape, namely Glenmore and Ndwayana. The identified infant health issue was used to design an educational intervention in the villages. This was the second phase of this study. A community-based participatory approach was utilized in which the Angus Gillis Foundation, a non-profit organization that works in these communities, was one of the stakeholders. Stock status of WHO priority medicines for infants, semi-structured interviews and focus group discussions were carried out during the baseline study. The intervention phase contained pre-2 intervention semi-structured interviews with ten pregnant women followed by an educational intervention with nine out of the ten; and finally, a post-intervention with seven out of the ten women. A questionnaire was completed by members of the Angus Gillis Foundation to provide feedback on the sustainability of the intervention. Semi-structured interviews revealed that medicines stocked at the clinic parallel those indicated in the WHO priority medicines list for infants. The results from the focus group discussions indicated that mothers do not exclusively breastfeed their infants during the first six months. Pre- and post-intervention results on exclusive breastfeeding illustrated a positive change in participants’ knowledge and intent to breastfeed exclusively for six months. They showed a better understanding of the importance of exclusive breastfeeding and indicated a more focussed intention and confidence to carry out optimal breastfeeding practices. In the questionnaire the members of the Angus Gillis Foundation stated that the intervention is sustainable as it was linked with the existing networks. These include educational programs carried out in the villages by the foundation together with positive health champions, community health workers and women self-help groups; which will be able to build on the present knowledge base. Finally, the study also included the design of a booklet on the identified infant health issue. In conclusion, participants highlighted lack of understanding regarding breastfeeding as an issue of concern during the baseline phase of the study. This community-based educational intervention improved the understanding of breastfeeding among the participants, resulting in a positive change in perception with regards to exclusive breastfeeding practices.
- Full Text:
- Date Issued: 2021
Parametrised gains for direction-dependent calibration
- Authors: Russeeaeon, Cyndie
- Date: 2021
- Subjects: Radio astronomy , Radio inferometers , Radio inferometers -- Calibration
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/172400 , vital:42196
- Description: Calibration in radio interferometry describes the process of estimating and correcting for instrumental errors from data. Direction-Dependent (DD) calibration entails correcting for corruptions which vary across the sky. For small field of view observations, DD corruptions can be ignored but for wide fild observations, it is crucial to account for them. Traditional maximum likelihood calibration is not necessarily efficient in low signal-to-noise ratio (SNR) scenarios and this can lead to ovefitting. This can bias continuum subtraction and hence, restrict the spectral line studies. Since DD effects are expected to vary smoothly across the sky, the gains can be parametrised as a smooth function of the sky coordinates. Hence, we implement a solver where the atmosphere is modelled using a time-variant 2-dimensional phase screen with an arbitrary known frequency dependence. We assume arbitrary linear basis functions for the gains over the phase screen. The implemented solver is ptimised using the diagonal approximation of the Hessian as shown in previous studies. We present a few simulations to illustrate the performance of the solver.
- Full Text:
- Date Issued: 2021
- Authors: Russeeaeon, Cyndie
- Date: 2021
- Subjects: Radio astronomy , Radio inferometers , Radio inferometers -- Calibration
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/172400 , vital:42196
- Description: Calibration in radio interferometry describes the process of estimating and correcting for instrumental errors from data. Direction-Dependent (DD) calibration entails correcting for corruptions which vary across the sky. For small field of view observations, DD corruptions can be ignored but for wide fild observations, it is crucial to account for them. Traditional maximum likelihood calibration is not necessarily efficient in low signal-to-noise ratio (SNR) scenarios and this can lead to ovefitting. This can bias continuum subtraction and hence, restrict the spectral line studies. Since DD effects are expected to vary smoothly across the sky, the gains can be parametrised as a smooth function of the sky coordinates. Hence, we implement a solver where the atmosphere is modelled using a time-variant 2-dimensional phase screen with an arbitrary known frequency dependence. We assume arbitrary linear basis functions for the gains over the phase screen. The implemented solver is ptimised using the diagonal approximation of the Hessian as shown in previous studies. We present a few simulations to illustrate the performance of the solver.
- Full Text:
- Date Issued: 2021
Synthesis, spectroscopic and nonlinear optical properties of asymmetric A3B type phthalocyanine complexes
- Authors: Mugeza, Rhulani Donney
- Date: 2021
- Subjects: Spectrum analysis , Mass spectrometry , Phthalocyanines
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/171667 , vital:42108
- Description: This work reports on the synthesis of symmetrical and asymmetrical A 3 B type metal free, cobalt and zinc Phthalocyanines (Pc) .A wide range of spectroscopic techniques such as Uv - visible absorption (UV), magnetic circular dichroism (MCD), mass spectrometry, elemental analysis, IR spectroscopy and time correlated single photo n counting spectroscopy (TCSPC) have been used to study the spectroscopic properties of the phthalocyanine complexes. The Z - scan technique was used to comparatively investigate the nonlinear absorption coefficient ( 휷 ) and the nonlinear refraction index ( 풏 ퟐ ) of the synthesized complexes. The following trend was obtained for the synthesized Pc’s in terms of the 휷 values 7.25 × 10 − 10 ( 4b ) > 3.76 × 10 − 10 ( 4a ) > 3.52 × 10 − 10 ( 4c ) > 2.29 × 10 − 10 ( 3c ) > 1.68 × 10 − 10 ( 3a ) > 1.65 × 10 − 10 ( 3b ) mW - 1 . The 휷 values trend of synthesized Pc complexes show that the asymmetrical A 3 B type metal free, cobalt and zinc Pc complexes ( 4a , 4b and 4c ) have larger 휷 values as compared to the octa - substituted symmetrical metal free, cobalt and zinc Pc complexes ( 3a , 3b and 3c ) which is attributed to the low symmetry of the Pc complexes. The five - level model rate equations were used to determine the two photon absorption, excited state absorption and ground state absorption cross sections of the synthesized complexes. The z inc A 3 B type asymmetrical Pc complexes gave the largest two photon absorption and 휎 푒 / 휎 푔 ratio values. This Pc complex could be used in future work to enhance the nonlinear response further by introducing nanomaterials and converting the Pc complex to a binuclear Pc. This work also reports on the density functional theory (DFT) calculations o f dipolar/octupolar contributions in order to study the first order hyperpolarizability of the synthesized Pc complexes.
- Full Text:
- Date Issued: 2021
- Authors: Mugeza, Rhulani Donney
- Date: 2021
- Subjects: Spectrum analysis , Mass spectrometry , Phthalocyanines
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/171667 , vital:42108
- Description: This work reports on the synthesis of symmetrical and asymmetrical A 3 B type metal free, cobalt and zinc Phthalocyanines (Pc) .A wide range of spectroscopic techniques such as Uv - visible absorption (UV), magnetic circular dichroism (MCD), mass spectrometry, elemental analysis, IR spectroscopy and time correlated single photo n counting spectroscopy (TCSPC) have been used to study the spectroscopic properties of the phthalocyanine complexes. The Z - scan technique was used to comparatively investigate the nonlinear absorption coefficient ( 휷 ) and the nonlinear refraction index ( 풏 ퟐ ) of the synthesized complexes. The following trend was obtained for the synthesized Pc’s in terms of the 휷 values 7.25 × 10 − 10 ( 4b ) > 3.76 × 10 − 10 ( 4a ) > 3.52 × 10 − 10 ( 4c ) > 2.29 × 10 − 10 ( 3c ) > 1.68 × 10 − 10 ( 3a ) > 1.65 × 10 − 10 ( 3b ) mW - 1 . The 휷 values trend of synthesized Pc complexes show that the asymmetrical A 3 B type metal free, cobalt and zinc Pc complexes ( 4a , 4b and 4c ) have larger 휷 values as compared to the octa - substituted symmetrical metal free, cobalt and zinc Pc complexes ( 3a , 3b and 3c ) which is attributed to the low symmetry of the Pc complexes. The five - level model rate equations were used to determine the two photon absorption, excited state absorption and ground state absorption cross sections of the synthesized complexes. The z inc A 3 B type asymmetrical Pc complexes gave the largest two photon absorption and 휎 푒 / 휎 푔 ratio values. This Pc complex could be used in future work to enhance the nonlinear response further by introducing nanomaterials and converting the Pc complex to a binuclear Pc. This work also reports on the density functional theory (DFT) calculations o f dipolar/octupolar contributions in order to study the first order hyperpolarizability of the synthesized Pc complexes.
- Full Text:
- Date Issued: 2021
The changing nature of work: understanding precarity and the gendered individualisation of risk in post-apartheid South Africa
- Authors: Mhlana, Siviwe
- Date: 2021
- Subjects: Precarious employment , Labor supply -- South Africa , Labor supply -- Statistics -- South Africa , Precarious employment -- South Africa , Informal sector (Economics) -- Employees -- South Africa , Women employees -- South Africa , Women temporary employees -- South Africa
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/172146 , vital:42170
- Description: Against the backdrop of workplace restructuring globally, post-Apartheid South Africa is experiencing consistently high levels of unemployment, the deterioration of employment security, and limited improvements in earnings. This trend in the proliferation of low-paid, unstable and otherwise insecure employment has given rise to a segment of the literature that is centred on the growing precariousness of work in a number of different contexts. This thesis reviews empirical work on the changing nature of labour-intensive production in the past two decades, with particular focus on the trends in non-standard, informal and precarious employment. Further, the thesis examines the shift in the gender structure of South Africa’s manufacturing sector and how it affects the share in the benefits of employment, particularly with regard to social reproduction. In so doing, the thesis expands the critical theoretical narrative about the challenges of labour under neoliberalism by providing an intersectional perspective of precarious work in post- Apartheid South Africa.
- Full Text:
- Date Issued: 2021
- Authors: Mhlana, Siviwe
- Date: 2021
- Subjects: Precarious employment , Labor supply -- South Africa , Labor supply -- Statistics -- South Africa , Precarious employment -- South Africa , Informal sector (Economics) -- Employees -- South Africa , Women employees -- South Africa , Women temporary employees -- South Africa
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/172146 , vital:42170
- Description: Against the backdrop of workplace restructuring globally, post-Apartheid South Africa is experiencing consistently high levels of unemployment, the deterioration of employment security, and limited improvements in earnings. This trend in the proliferation of low-paid, unstable and otherwise insecure employment has given rise to a segment of the literature that is centred on the growing precariousness of work in a number of different contexts. This thesis reviews empirical work on the changing nature of labour-intensive production in the past two decades, with particular focus on the trends in non-standard, informal and precarious employment. Further, the thesis examines the shift in the gender structure of South Africa’s manufacturing sector and how it affects the share in the benefits of employment, particularly with regard to social reproduction. In so doing, the thesis expands the critical theoretical narrative about the challenges of labour under neoliberalism by providing an intersectional perspective of precarious work in post- Apartheid South Africa.
- Full Text:
- Date Issued: 2021
The effect of habitat and spatial management on reef fish in an established marine protected area
- Authors: Dames, Vivienne Abigail
- Date: 2021
- Subjects: iSimangaliso Wetland Park (South Africa) -- Management , Reef fishes -- South Africa -- KwaZulu-Natal , Baited remote underwater stereo-video systems (stereo-BRUVs) , Marine parks and reserves -- Monitoring -- South Africa -- KwaZulu-Natal , Fish populations -- Measurement
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/171150 , vital:42024
- Description: The persistence of harvested fish populations in the Anthropocene will be determined, above all, by how they respond to the interacting effects of climate change and fisheries exploitation. Predicting how populations will respond to both these threats is essential for any adaptive and sustainable management strategy. The response of fish populations to climate change is underpinned by physiological rates and tolerances, and emerging evidence suggests there may be physiological-based selection in capture fisheries. By quantifying important physiological rates of a model species, the endemic seabream, Chrysoblephus laticeps, across ecologically relevant thermal gradients and from populations subjected to varying intensities of commercial exploitation, this thesis aimed to 1) provide the first physiologically grounded climate resilience assessment for a South African linefish species, and 2) elucidate whether exploitation can drive populations to less physiologically resilient states in response to climate change. To identify physiologically limiting sea temperatures and to determine if exploitation alters physiological trait distributions, an intermittent flow respirometry experiment was used to test the metabolic response of spatially protected and exploited populations of C. laticeps to acute thermal variability. Exploited populations showed reduced metabolic phenotype diversity, fewer high-performance aerobic scope phenotypes, and a significantly lower aerobic scope curve across all test temperatures. Although both populations maintained a relatively high aerobic scope across a wide thermal range, their metabolic rates were compromised when extreme cold events were simulated (8 °C), suggesting that predicted future increases in upwelling frequency and intensity may be the primary limiting factor in a more thermally variable future ocean. The increment widths of annuli in the otoliths of C. laticeps from contemporary and historic collections were measured, as a proxy for the annual growth rate of exploited and protected populations. Hierarchical mixed models were used to partition growth variation within and among individuals and ascribe growth to intrinsic and extrinsic effects. The best model for the protected population indicated that the growth response of C. laticeps was poorer during years characterised by a high cumulative upwelling intensity, and better during years characterised by higher mean autumn sea surface temperatures. The exploited population growth chronology was too short to identify an extrinsic growth driver. The growth results again highlight the role of thermal variability in modulating the response of C. laticeps to its ambient environment and indicate that the predicted increases in upwelling frequency and intensity may constrain future growth rates of this species. A metabolic index (ϕ), representing the ratio of O2 supply to demand at various temperatures and oxygen concentrations, was estimated for exploited and protected populations of C. laticeps and used to predict future distribution responses. There was no difference in the laboratory calibrations of ϕ between populations, and all data was subsequently combined into a single piecewise (12 °C) calibrated ϕ model. To predict the distribution of C. laticeps, ϕ was projected across a high-resolution ocean model of the South African coastal zone, and a species distribution model implemented using the random forest algorithm and C. laticeps occurrence points. The future distribution of C. laticeps was estimated by predicting trained models across ocean model projections up to 2100. The best predictor of C. laticeps’ current distribution was minimum monthly ϕ and future predictions indicated only a slight range contraction on either edge of C. laticeps’ distribution by 2100. In order to provide policy makers, currently developing climate change management frameworks for South Africa’s ocean, with a usable output, the results of all research chapters were combined into a marine spatial model. The spatial model identified areas where C. laticeps is predicted to be resilient to climate change in terms of physiology, growth and distribution responses, which can then be prioritised for adaptation measures, such as spatial protection from exploitation. While these results are specific to C. laticeps, the methodology developed to identify areas of climate resilience has broad applications across taxa. From a global perspective, perhaps the most salient points to consider from this case study are the evidence of selective exploitation on physiological traits and the importance of environmental variability, rather than long-term mean climate changes, in affecting organism performance. These ideas are congruent with the current paradigm shift in how we think of the ocean, selective fisheries, and how they relate to organism climate resilience.
- Full Text:
- Date Issued: 2021
- Authors: Dames, Vivienne Abigail
- Date: 2021
- Subjects: iSimangaliso Wetland Park (South Africa) -- Management , Reef fishes -- South Africa -- KwaZulu-Natal , Baited remote underwater stereo-video systems (stereo-BRUVs) , Marine parks and reserves -- Monitoring -- South Africa -- KwaZulu-Natal , Fish populations -- Measurement
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/171150 , vital:42024
- Description: The persistence of harvested fish populations in the Anthropocene will be determined, above all, by how they respond to the interacting effects of climate change and fisheries exploitation. Predicting how populations will respond to both these threats is essential for any adaptive and sustainable management strategy. The response of fish populations to climate change is underpinned by physiological rates and tolerances, and emerging evidence suggests there may be physiological-based selection in capture fisheries. By quantifying important physiological rates of a model species, the endemic seabream, Chrysoblephus laticeps, across ecologically relevant thermal gradients and from populations subjected to varying intensities of commercial exploitation, this thesis aimed to 1) provide the first physiologically grounded climate resilience assessment for a South African linefish species, and 2) elucidate whether exploitation can drive populations to less physiologically resilient states in response to climate change. To identify physiologically limiting sea temperatures and to determine if exploitation alters physiological trait distributions, an intermittent flow respirometry experiment was used to test the metabolic response of spatially protected and exploited populations of C. laticeps to acute thermal variability. Exploited populations showed reduced metabolic phenotype diversity, fewer high-performance aerobic scope phenotypes, and a significantly lower aerobic scope curve across all test temperatures. Although both populations maintained a relatively high aerobic scope across a wide thermal range, their metabolic rates were compromised when extreme cold events were simulated (8 °C), suggesting that predicted future increases in upwelling frequency and intensity may be the primary limiting factor in a more thermally variable future ocean. The increment widths of annuli in the otoliths of C. laticeps from contemporary and historic collections were measured, as a proxy for the annual growth rate of exploited and protected populations. Hierarchical mixed models were used to partition growth variation within and among individuals and ascribe growth to intrinsic and extrinsic effects. The best model for the protected population indicated that the growth response of C. laticeps was poorer during years characterised by a high cumulative upwelling intensity, and better during years characterised by higher mean autumn sea surface temperatures. The exploited population growth chronology was too short to identify an extrinsic growth driver. The growth results again highlight the role of thermal variability in modulating the response of C. laticeps to its ambient environment and indicate that the predicted increases in upwelling frequency and intensity may constrain future growth rates of this species. A metabolic index (ϕ), representing the ratio of O2 supply to demand at various temperatures and oxygen concentrations, was estimated for exploited and protected populations of C. laticeps and used to predict future distribution responses. There was no difference in the laboratory calibrations of ϕ between populations, and all data was subsequently combined into a single piecewise (12 °C) calibrated ϕ model. To predict the distribution of C. laticeps, ϕ was projected across a high-resolution ocean model of the South African coastal zone, and a species distribution model implemented using the random forest algorithm and C. laticeps occurrence points. The future distribution of C. laticeps was estimated by predicting trained models across ocean model projections up to 2100. The best predictor of C. laticeps’ current distribution was minimum monthly ϕ and future predictions indicated only a slight range contraction on either edge of C. laticeps’ distribution by 2100. In order to provide policy makers, currently developing climate change management frameworks for South Africa’s ocean, with a usable output, the results of all research chapters were combined into a marine spatial model. The spatial model identified areas where C. laticeps is predicted to be resilient to climate change in terms of physiology, growth and distribution responses, which can then be prioritised for adaptation measures, such as spatial protection from exploitation. While these results are specific to C. laticeps, the methodology developed to identify areas of climate resilience has broad applications across taxa. From a global perspective, perhaps the most salient points to consider from this case study are the evidence of selective exploitation on physiological traits and the importance of environmental variability, rather than long-term mean climate changes, in affecting organism performance. These ideas are congruent with the current paradigm shift in how we think of the ocean, selective fisheries, and how they relate to organism climate resilience.
- Full Text:
- Date Issued: 2021
The impact of labour legislation on selected small firms in Mbombela (Nelspruit)
- Authors: Dlamini, Sikhulile Blessing
- Date: 2021
- Subjects: Labor laws and legislation -- South Africa , Small business -- Law and legislation-- South Afric , Small business -- South Africa -- Mbombela -- Case studies
- Language: English
- Type: text , Thesis , Masters , MSocSci
- Identifier: http://hdl.handle.net/10962/170781 , vital:41959
- Description: This study uses the theoretical framework of industrial relations pluralism, to study and analyse the impacts of labour legislation on six small firms (employing less than 50 workers) based in Mbombela (formerly Nelspruit), Mpumalanga province, South Africa. The analysis is based on the viewpoints of six managers and how they see the impacts of labour legislation on their respective firms. The analysis is aided by utilising theory and literature to make sense of the manager perspectives on the topic. Also, utilising a qualitative research design to collect and analyse the data, the study presents diverse findings in terms of how the participants perceived and experienced certain types of legislation. Some managers believed that the benefits of labour legislation outweighed the costs. While others believed the exact opposite. At an overall level, the study revealed that most of the participants were not as severely affected by labour legislation as might be expected; given the scarcity of resources in most small firms. This was partly because of various coping strategies and practices (mostly involving the use of informal procedures) that were adopted by the firms. Also, some small firms who aimed at expanding their businesses strategised to adopt some formal procedures and practices in order to easily absorb labour legislation and subsequently mordenise their businesses in the process. While a few firms persisted with more informal customs as they appeared cost-effective and necessary in their particular market positioning.
- Full Text:
- Date Issued: 2021
- Authors: Dlamini, Sikhulile Blessing
- Date: 2021
- Subjects: Labor laws and legislation -- South Africa , Small business -- Law and legislation-- South Afric , Small business -- South Africa -- Mbombela -- Case studies
- Language: English
- Type: text , Thesis , Masters , MSocSci
- Identifier: http://hdl.handle.net/10962/170781 , vital:41959
- Description: This study uses the theoretical framework of industrial relations pluralism, to study and analyse the impacts of labour legislation on six small firms (employing less than 50 workers) based in Mbombela (formerly Nelspruit), Mpumalanga province, South Africa. The analysis is based on the viewpoints of six managers and how they see the impacts of labour legislation on their respective firms. The analysis is aided by utilising theory and literature to make sense of the manager perspectives on the topic. Also, utilising a qualitative research design to collect and analyse the data, the study presents diverse findings in terms of how the participants perceived and experienced certain types of legislation. Some managers believed that the benefits of labour legislation outweighed the costs. While others believed the exact opposite. At an overall level, the study revealed that most of the participants were not as severely affected by labour legislation as might be expected; given the scarcity of resources in most small firms. This was partly because of various coping strategies and practices (mostly involving the use of informal procedures) that were adopted by the firms. Also, some small firms who aimed at expanding their businesses strategised to adopt some formal procedures and practices in order to easily absorb labour legislation and subsequently mordenise their businesses in the process. While a few firms persisted with more informal customs as they appeared cost-effective and necessary in their particular market positioning.
- Full Text:
- Date Issued: 2021
The invasion ecology of Pontederia cordata L. (Pontederiaceae) in South Africa
- Authors: Wansell, Sage Nora-Lee
- Date: 2021
- Subjects: Plant invsions -- South AFrica , Invasive plants -- Ecology -- South Africa , Pontederiaceae -- South AFrica
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/172433 , vital:42200
- Description: Pontederia cordata L. (Pontederiaceae) is a tristylous invasive macrophyte – originating from North and South America – that has caused detrimental environmental, agricultural and socio-economic impacts in South Africa (SA). This novel study investigates the invasive ecology of P. cordata in SA by determining population genetics, pollination ecology and floral traits. Preliminary field surveys suggest that only one of three tristylous forms of P. cordata is invading SA and no seeds have been observed in any invasive populations. This study therefore determined the population genetics, mode of spread of P. cordata in SA and possible reasons for the lack of seed production, as well as providing suggestions for future control and management strategies. Inter Simple Sequence Repeats of leaf samples from invasive populations in SA and the native range of the United States of America (USA) were performed to determine the population genetics of P. cordata. The clarification of population structure of an alien invasive plant can provide insight into founder effects, introduction events and modes of spread and is important for the development of management plans such as biological control. Results from the genetic analyses indicated that P. cordata populations have low genetic diversity within and amongst invasive populations in comparison to native populations. This suggests that high gene flow and sexual reproduction is not present in invasive populations, and that only a single or very few introductory events have occurred in SA. Furthermore, invasive P. cordata populations shared the highest genetic similarity with native samples from Belle Haven, Virginia, USA, and thus further sampling and future genetic surveys should be conducted in this area to identify source populations to survey for potential biological control agents. Following these findings, I investigated whether sexual reproduction and seed production is absent from invasive P. cordata populations in SA as speculated. Floral traits from populations throughout all the invaded provinces were measured and, along with pollen grain measurements, it was determined that only short-morphed plants are present in SA. It was speculated that the absence of native pollinators in the invasive range may be responsible for the absence of sexual reproduction. However, a pollination study confirmed the presence of generalist insect pollinators. Thereafter, artificial pollination experiments on 8 865 flowers were conducted to determine whether an incompatibility system was present which prevented seed production. No seeds were produced and it was concluded that illegitimate pollination of the short-morphed plants prevented seed production and rhizomes are responsible for the invasion of P. cordata throughout SA. The implications of these findings and possible management strategies such as biological control is discussed in Chapter 4. These findings suggest that control programmes should target the plants rhizomes to prevent and reduce spread. Preventing the introduction of medium- and long-morphed plants into SA is crucial to prevent P. cordata from producing seeds and intensifying invasion further through both asexual and sexual spread.
- Full Text:
- Date Issued: 2021
- Authors: Wansell, Sage Nora-Lee
- Date: 2021
- Subjects: Plant invsions -- South AFrica , Invasive plants -- Ecology -- South Africa , Pontederiaceae -- South AFrica
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/172433 , vital:42200
- Description: Pontederia cordata L. (Pontederiaceae) is a tristylous invasive macrophyte – originating from North and South America – that has caused detrimental environmental, agricultural and socio-economic impacts in South Africa (SA). This novel study investigates the invasive ecology of P. cordata in SA by determining population genetics, pollination ecology and floral traits. Preliminary field surveys suggest that only one of three tristylous forms of P. cordata is invading SA and no seeds have been observed in any invasive populations. This study therefore determined the population genetics, mode of spread of P. cordata in SA and possible reasons for the lack of seed production, as well as providing suggestions for future control and management strategies. Inter Simple Sequence Repeats of leaf samples from invasive populations in SA and the native range of the United States of America (USA) were performed to determine the population genetics of P. cordata. The clarification of population structure of an alien invasive plant can provide insight into founder effects, introduction events and modes of spread and is important for the development of management plans such as biological control. Results from the genetic analyses indicated that P. cordata populations have low genetic diversity within and amongst invasive populations in comparison to native populations. This suggests that high gene flow and sexual reproduction is not present in invasive populations, and that only a single or very few introductory events have occurred in SA. Furthermore, invasive P. cordata populations shared the highest genetic similarity with native samples from Belle Haven, Virginia, USA, and thus further sampling and future genetic surveys should be conducted in this area to identify source populations to survey for potential biological control agents. Following these findings, I investigated whether sexual reproduction and seed production is absent from invasive P. cordata populations in SA as speculated. Floral traits from populations throughout all the invaded provinces were measured and, along with pollen grain measurements, it was determined that only short-morphed plants are present in SA. It was speculated that the absence of native pollinators in the invasive range may be responsible for the absence of sexual reproduction. However, a pollination study confirmed the presence of generalist insect pollinators. Thereafter, artificial pollination experiments on 8 865 flowers were conducted to determine whether an incompatibility system was present which prevented seed production. No seeds were produced and it was concluded that illegitimate pollination of the short-morphed plants prevented seed production and rhizomes are responsible for the invasion of P. cordata throughout SA. The implications of these findings and possible management strategies such as biological control is discussed in Chapter 4. These findings suggest that control programmes should target the plants rhizomes to prevent and reduce spread. Preventing the introduction of medium- and long-morphed plants into SA is crucial to prevent P. cordata from producing seeds and intensifying invasion further through both asexual and sexual spread.
- Full Text:
- Date Issued: 2021
The potential conflict of interest associated with the management of Rosa rubiginos L. (Rosehip) in South Africa
- Authors: Westwood, Timothy
- Date: 2021
- Subjects: Invasive plants -- South Africa , Biological invasions -- Economic aspects , Rose hips -- Economic aspects -- South Africa , Roses -- South Africa , Rose culture -- Economic aspects -- South Africa
- Language: English
- Type: text , Thesis , Masters , MCom
- Identifier: http://hdl.handle.net/10962/172458 , vital:42204
- Description: Rosa rubiginosa L. is a category 1b invasive plant species in South Africa and must be controlled according to NEM:BA. However, R. rubiginosa has the potential to provide economic benefit in South Africa due to the expanding market for the shrubs fruit, rosehips. The shrub is not permitted to be cultivated in South Africa due to legislation, limiting the economic potential as the rosehips are only able to be collected from wild R. rubiginosa shrubs. In order to expand the rosehip market in South Africa a downgrade or removal of R. rubiginosa from the invasive species list would be required, as wild harvest is limited. This study aims to assess the benefits and cost associated with R. rubiginosa in order to determine whether the legislation should be altered allowing for the cultivation of the shrub in South Africa. Due to the limited literature surrounding R. rubiginosa three different questionnaires and a case study were used in order to assess the benefits and negatives associated with the shrub. Experts in the field of invasion biology were surveyed to bridge the gap in the R. rubiginosa literature. Landowners, where the shrub is abundant, were surveyed to determine the negative impacts of R. rubiginosa. Rosehip companies were surveyed in order to determine the current size and potential of the R. rubiginosa (rosehip) market. The case study looked at how a rosehip company would benefit if R. rubiginosa was allowed to be cultivated in South Africa. The study found R. rubiginosa to have great economic potential and market growth, with very little negative economic impact. The case study showed that one rosehip company would grow from 1500 tons of raw rosehip to 20 000 tons if cultivation was allowed, resulting in a growth in turnover from R57 million to R760 million ($1=R14.8). The findings in the study show that R. rubiginosa does not significantly affect landowners where it is abundant. Therefore, it is suggested that a change to the legislation should be considered allowing for the cultivation of R. rubiginosa should be implemented.
- Full Text:
- Date Issued: 2021
- Authors: Westwood, Timothy
- Date: 2021
- Subjects: Invasive plants -- South Africa , Biological invasions -- Economic aspects , Rose hips -- Economic aspects -- South Africa , Roses -- South Africa , Rose culture -- Economic aspects -- South Africa
- Language: English
- Type: text , Thesis , Masters , MCom
- Identifier: http://hdl.handle.net/10962/172458 , vital:42204
- Description: Rosa rubiginosa L. is a category 1b invasive plant species in South Africa and must be controlled according to NEM:BA. However, R. rubiginosa has the potential to provide economic benefit in South Africa due to the expanding market for the shrubs fruit, rosehips. The shrub is not permitted to be cultivated in South Africa due to legislation, limiting the economic potential as the rosehips are only able to be collected from wild R. rubiginosa shrubs. In order to expand the rosehip market in South Africa a downgrade or removal of R. rubiginosa from the invasive species list would be required, as wild harvest is limited. This study aims to assess the benefits and cost associated with R. rubiginosa in order to determine whether the legislation should be altered allowing for the cultivation of the shrub in South Africa. Due to the limited literature surrounding R. rubiginosa three different questionnaires and a case study were used in order to assess the benefits and negatives associated with the shrub. Experts in the field of invasion biology were surveyed to bridge the gap in the R. rubiginosa literature. Landowners, where the shrub is abundant, were surveyed to determine the negative impacts of R. rubiginosa. Rosehip companies were surveyed in order to determine the current size and potential of the R. rubiginosa (rosehip) market. The case study looked at how a rosehip company would benefit if R. rubiginosa was allowed to be cultivated in South Africa. The study found R. rubiginosa to have great economic potential and market growth, with very little negative economic impact. The case study showed that one rosehip company would grow from 1500 tons of raw rosehip to 20 000 tons if cultivation was allowed, resulting in a growth in turnover from R57 million to R760 million ($1=R14.8). The findings in the study show that R. rubiginosa does not significantly affect landowners where it is abundant. Therefore, it is suggested that a change to the legislation should be considered allowing for the cultivation of R. rubiginosa should be implemented.
- Full Text:
- Date Issued: 2021
Towards the development of a pro-environmental strategy for improving catch-and-release behaviour in recreational fisheries – a case study on a competitive South African angling body
- Authors: Mannheim, Samantha L
- Date: 2021
- Subjects: Fishing -- Environmental aspects -- South Africa , Fishing -- South Africa , Fishers -- Attitudes -- South Africa , Fishers -- Attitudes -- South Africa -- Cast studies , Fishes -- Conservation -- South Africa , Rock and Surf Super Pro League , Southern African Fisheries Ecology Research Lab
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/171862 , vital:42133
- Description: Catch-and-release (C&R) is becoming increasingly popular in recreational fisheries with the potential to contribute towards conserving the oceans limited fish stocks. Several studies have highlighted high rates of mortality and many sub-lethal effects which ultimately have a negative impact on fish population viability. With poorly developed handling practices, the fish that are released suffer the consequences of physical and physiological stress and do not always survive, thus making the ethics of C&R fishing questionable. Many studies have contributed to our understanding of the factors that influence the fate of fish released by anglers. Despite this, few interventions have been able to improve angler C&R behaviour. Pro-environmental behavioural strategies however hold some potential for improving angler C&R behaviour. To test their potential, we partnered with the South African Rock and Surf Super Pro League (RASSPL Africa), the biggest exclusively C&R competitive shore-based angling league in South Africa. The first two years (2013 and 2014) of the partnership were purely focused on building trust and relationships and making observations on angler behaviour. In 2015, we collected baseline data on angler behaviour and fish health during the RASSPL national fishing competition. This was followed by comparable data collection at the following two national competitions in 2016 and 2017 after the introduction of a combination of pro- environmental behaviour interventions, including rule changes, improving angler knowledge, behavioural modelling, rewards, penalties and feedback to improve C&R behaviour. There were significant improvements in angler behaviour, including a decline in total air exposure from 101.93s ± 64.34 in 2015 to 77.37s ± 60.52 in 2017 (F(2,618) = 9.27, P < 0.01), and the time taken for an angler to place their fish into a bucket declined from 105.86s ± 69.47 in 2015 to 23.05s ± 24.13 in 2017 (F(2,556) = 158.71, P < 0.01). There were also improvements in the health of the fish, with a decline in the blood lactate concentration and mean reflex action mortality predictor (RAMP’s) scores for the dominant species, Diplodus capensis (lactate – 9.46 ± 3.80 mmol.l-1 in 2015 and 6.69 ± 2.99 mmol.l-1 in 2017, RAMP – 0.28 ± 0.22 in 2015 and 0.19 ± 0.17 in 2017), and Haploblapharus fuscus (lactate – 4.25 ± 1.89 mmol.l-1 in 2015 and 1.76 ± 0.78 mmol.l-1in 2017, RAMP – 0.15 ± 0.18 in 2015 and 0 ± 0 in 2017). In 2018, surveys were conducted to gain insight into angler demographics and external (social, economic, cultural and institutional) and internal factors (knowledge and awareness, motivations, attitudes and perceptions) associated with the RASSPL anglers. Surveys were also designed to assist in identifying what components were key drivers behind the angler’s behavioural changes. The demographic characteristics of RASSPL anglers were not dissimilar from the general recreational angling public in South Africa, suggesting that this kind of intervention may have potential at a broader scale. In terms of the drivers of behavioural change, the surveys revealed that 68% of respondents strongly agreed that the structural rule changes contributed to their improved behaviour. This was followed by the educational presentations (66% of the respondents) and modelling / demonstrative videos (59% of the respondents). The conservation prizes were considered less effective, with only 27% of anglers strongly agreeing that this intervention improved their C&R behaviour. Overall this study has demonstrated that it is possible to improve the C&R behaviour of anglers in a competitive setting, with the most effective component of the intervention being the use of rule changes (structural approach). These findings suggest that proenvironmental strategies hold potential for improving the C&R behaviour of anglers and the health of released fishes. It is suggested that interventions to improve C&R behaviour should aim to develop long-term relationships, and implement a broad range of well communicated strategies based on reliable data and sound rationality. Key words: marine shore-based fisheries; community engagement; pro- environmental behaviour; behavioural intervention.
- Full Text:
- Date Issued: 2021
- Authors: Mannheim, Samantha L
- Date: 2021
- Subjects: Fishing -- Environmental aspects -- South Africa , Fishing -- South Africa , Fishers -- Attitudes -- South Africa , Fishers -- Attitudes -- South Africa -- Cast studies , Fishes -- Conservation -- South Africa , Rock and Surf Super Pro League , Southern African Fisheries Ecology Research Lab
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/171862 , vital:42133
- Description: Catch-and-release (C&R) is becoming increasingly popular in recreational fisheries with the potential to contribute towards conserving the oceans limited fish stocks. Several studies have highlighted high rates of mortality and many sub-lethal effects which ultimately have a negative impact on fish population viability. With poorly developed handling practices, the fish that are released suffer the consequences of physical and physiological stress and do not always survive, thus making the ethics of C&R fishing questionable. Many studies have contributed to our understanding of the factors that influence the fate of fish released by anglers. Despite this, few interventions have been able to improve angler C&R behaviour. Pro-environmental behavioural strategies however hold some potential for improving angler C&R behaviour. To test their potential, we partnered with the South African Rock and Surf Super Pro League (RASSPL Africa), the biggest exclusively C&R competitive shore-based angling league in South Africa. The first two years (2013 and 2014) of the partnership were purely focused on building trust and relationships and making observations on angler behaviour. In 2015, we collected baseline data on angler behaviour and fish health during the RASSPL national fishing competition. This was followed by comparable data collection at the following two national competitions in 2016 and 2017 after the introduction of a combination of pro- environmental behaviour interventions, including rule changes, improving angler knowledge, behavioural modelling, rewards, penalties and feedback to improve C&R behaviour. There were significant improvements in angler behaviour, including a decline in total air exposure from 101.93s ± 64.34 in 2015 to 77.37s ± 60.52 in 2017 (F(2,618) = 9.27, P < 0.01), and the time taken for an angler to place their fish into a bucket declined from 105.86s ± 69.47 in 2015 to 23.05s ± 24.13 in 2017 (F(2,556) = 158.71, P < 0.01). There were also improvements in the health of the fish, with a decline in the blood lactate concentration and mean reflex action mortality predictor (RAMP’s) scores for the dominant species, Diplodus capensis (lactate – 9.46 ± 3.80 mmol.l-1 in 2015 and 6.69 ± 2.99 mmol.l-1 in 2017, RAMP – 0.28 ± 0.22 in 2015 and 0.19 ± 0.17 in 2017), and Haploblapharus fuscus (lactate – 4.25 ± 1.89 mmol.l-1 in 2015 and 1.76 ± 0.78 mmol.l-1in 2017, RAMP – 0.15 ± 0.18 in 2015 and 0 ± 0 in 2017). In 2018, surveys were conducted to gain insight into angler demographics and external (social, economic, cultural and institutional) and internal factors (knowledge and awareness, motivations, attitudes and perceptions) associated with the RASSPL anglers. Surveys were also designed to assist in identifying what components were key drivers behind the angler’s behavioural changes. The demographic characteristics of RASSPL anglers were not dissimilar from the general recreational angling public in South Africa, suggesting that this kind of intervention may have potential at a broader scale. In terms of the drivers of behavioural change, the surveys revealed that 68% of respondents strongly agreed that the structural rule changes contributed to their improved behaviour. This was followed by the educational presentations (66% of the respondents) and modelling / demonstrative videos (59% of the respondents). The conservation prizes were considered less effective, with only 27% of anglers strongly agreeing that this intervention improved their C&R behaviour. Overall this study has demonstrated that it is possible to improve the C&R behaviour of anglers in a competitive setting, with the most effective component of the intervention being the use of rule changes (structural approach). These findings suggest that proenvironmental strategies hold potential for improving the C&R behaviour of anglers and the health of released fishes. It is suggested that interventions to improve C&R behaviour should aim to develop long-term relationships, and implement a broad range of well communicated strategies based on reliable data and sound rationality. Key words: marine shore-based fisheries; community engagement; pro- environmental behaviour; behavioural intervention.
- Full Text:
- Date Issued: 2021