The tropical environment and malaria in southwestern Nigeria, 1861 – 1960
- Authors: Adetiba, Adedamola Seun
- Date: 2019
- Subjects: Diseases and history -- Africa , Diseases and history -- Nigeria , Medical anthropology -- Africa , Medical anthropology -- Nigeria , Malaria -- Social aspects -- Nigeria , Malaria -- Nigeria -- History , Nigeria -- History , Imperialism -- Health aspects , Medicine -- Colonies -- Great Britain -- History
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/76564 , vital:30605
- Description: This thesis is a social history of malaria in southwestern Nigeria. It contributes to the burgeoning literature in the historiography of medicine, specifically the medicine and empire debate. Key to the issues raised in this thesis is the extent to which the limitations in colonial medical policies, most especially malaria control programmes, inspired critical and ingenious responses from African nationalists, doctors, patients, research volunteers, and indigenous medical practitioners. Challenged by a wide range of diseases and a paucity of health facilities and disease control schemes, African rural dwellers became medical pluralists in the ways they imagined and appropriated ideas of Western medicine alongside their indigenous medical practices. Beginning with a detailed historical exploration of the issues that informed the introduction of curative and preventive medicine in southwestern Nigeria, this thesis reveals the focus of colonial medicine. It exposes the one-sided nature of medical services in colonial spaces like southwestern Nigeria and the ways it shaped multifaceted responses from Africans, who were specifically side-lined till the 1950s when the rural medical service scheme was introduced. The focus of colonial medicine is drawn from relatively rich but often subjective historical evidence, such as a plethora of official reports of the department of medical and sanitary services, official correspondences within the colonial government in Lagos and Nigeria, and between the colonial government and the colonial office in the United Kingdom. Details of African responses to medical policies were garnered from newspaper publications and correspondences between the African public and the colonial government in Lagos. They reveal very interesting details of the ways Africans imagined, reimagined, and appropriated malaria control ideas and schemes. The central argument in this thesis is that attempts to control malaria in southwestern Nigeria till the 1950s, were shaped by a single concern to ameliorate the implications of the disease on the colonial state. It argues that this one-sided nature of malaria control programme informed the basis for medical pluralism in most rural spaces where African communities became patrons and sponsors of Western medicine and at the same time custodians of their indigenous medical practices. The series of justifications for the sustenance of these services were reinforced on the basis of the failure of the colonial state to guarantee the health needs of their colonial subjects. The aim of the thesis is to reinforce arguments that portray colonial medicine as a “tool of empire” but goes a bit further to explain the extent to which Africans related to this reality. It states quite categorically that Africans were not docile and silent, but that they acted decisively in ways that suited their varied interests and courses.
- Full Text:
- Authors: Adetiba, Adedamola Seun
- Date: 2019
- Subjects: Diseases and history -- Africa , Diseases and history -- Nigeria , Medical anthropology -- Africa , Medical anthropology -- Nigeria , Malaria -- Social aspects -- Nigeria , Malaria -- Nigeria -- History , Nigeria -- History , Imperialism -- Health aspects , Medicine -- Colonies -- Great Britain -- History
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/76564 , vital:30605
- Description: This thesis is a social history of malaria in southwestern Nigeria. It contributes to the burgeoning literature in the historiography of medicine, specifically the medicine and empire debate. Key to the issues raised in this thesis is the extent to which the limitations in colonial medical policies, most especially malaria control programmes, inspired critical and ingenious responses from African nationalists, doctors, patients, research volunteers, and indigenous medical practitioners. Challenged by a wide range of diseases and a paucity of health facilities and disease control schemes, African rural dwellers became medical pluralists in the ways they imagined and appropriated ideas of Western medicine alongside their indigenous medical practices. Beginning with a detailed historical exploration of the issues that informed the introduction of curative and preventive medicine in southwestern Nigeria, this thesis reveals the focus of colonial medicine. It exposes the one-sided nature of medical services in colonial spaces like southwestern Nigeria and the ways it shaped multifaceted responses from Africans, who were specifically side-lined till the 1950s when the rural medical service scheme was introduced. The focus of colonial medicine is drawn from relatively rich but often subjective historical evidence, such as a plethora of official reports of the department of medical and sanitary services, official correspondences within the colonial government in Lagos and Nigeria, and between the colonial government and the colonial office in the United Kingdom. Details of African responses to medical policies were garnered from newspaper publications and correspondences between the African public and the colonial government in Lagos. They reveal very interesting details of the ways Africans imagined, reimagined, and appropriated malaria control ideas and schemes. The central argument in this thesis is that attempts to control malaria in southwestern Nigeria till the 1950s, were shaped by a single concern to ameliorate the implications of the disease on the colonial state. It argues that this one-sided nature of malaria control programme informed the basis for medical pluralism in most rural spaces where African communities became patrons and sponsors of Western medicine and at the same time custodians of their indigenous medical practices. The series of justifications for the sustenance of these services were reinforced on the basis of the failure of the colonial state to guarantee the health needs of their colonial subjects. The aim of the thesis is to reinforce arguments that portray colonial medicine as a “tool of empire” but goes a bit further to explain the extent to which Africans related to this reality. It states quite categorically that Africans were not docile and silent, but that they acted decisively in ways that suited their varied interests and courses.
- Full Text:
Learning to learn: a critical realist exploration into the home established learning practices of a marginalised community in Port Elizabeth
- Authors: Armstrong, Meredith
- Date: 2019
- Subjects: Minorities -- Education (Higher) -- South Africa , Readiness for school -- Social aspects -- South Africa , Inclusive education -- Social aspects -- South Africa , Marginality, Social -- South Africa , Critical realism
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/93778 , vital:30939
- Description: This study was completed as part of a project exploring social inclusion and exclusion in South African higher education. In a globalised world, the achievement of a qualification from an institution of higher education is increasingly key to finding any sort of employment. This is particularly the case in South Africa where employment amongst black citizens is inordinately high. The aim of the research reported upon in this thesis was to better understand the construct of ‘epistemological access’ (Morrow, 1992), often used in relation to the needs of black working class students entering higher education, in relation to performance data (see for example, CHE, 2016) that repeatedly shows that black students fare less well than their white peers. Following what might be termed a ‘social’ approach to understanding access, this study begins long before most students have even heard of higher education and focuses on identifying the mechanisms that come into play at much earlier level of learning and literacy development. The study outlines the development of ‘ways of being’, or social practices, surrounding learning in a marginalised community in Port Elizabeth, in the Eastern Cape, South Africa. This was achieved by means of critical ethnography and it is therefore qualitatively based. The study shows how social structures enable or constrain a child’s school readiness and how they then go on to support or impede progress in school where the language and literacy needed for educational success are further developed. The study therefore aims to allow us to explain global data indicating that the single greatest indicator of a young person’s ability to access and succeed in higher education is the level of education of caregivers in their homes of origin. Examined from a critical perspective (i.e. with a concern for social justice), this study has made use of a framework using social, psychological and linguistic theory and more, particularly, the work of sociologist Margaret Archer (1995, 1996, 2003). The study makes particular use of Archer’s ‘morphogenetic framework’ which allows for an analysis of the way structure and culture impact on a child’s development over time. As I was concerned that my own social status might impact on the understandings I developed as a critical ethnographer, the study acknowledges my own experiences of learning and the way my own family sought to enhance them as enabling. In doing this, the study aims to better contribute to understandings of social justice in South Africa.
- Full Text:
- Authors: Armstrong, Meredith
- Date: 2019
- Subjects: Minorities -- Education (Higher) -- South Africa , Readiness for school -- Social aspects -- South Africa , Inclusive education -- Social aspects -- South Africa , Marginality, Social -- South Africa , Critical realism
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/93778 , vital:30939
- Description: This study was completed as part of a project exploring social inclusion and exclusion in South African higher education. In a globalised world, the achievement of a qualification from an institution of higher education is increasingly key to finding any sort of employment. This is particularly the case in South Africa where employment amongst black citizens is inordinately high. The aim of the research reported upon in this thesis was to better understand the construct of ‘epistemological access’ (Morrow, 1992), often used in relation to the needs of black working class students entering higher education, in relation to performance data (see for example, CHE, 2016) that repeatedly shows that black students fare less well than their white peers. Following what might be termed a ‘social’ approach to understanding access, this study begins long before most students have even heard of higher education and focuses on identifying the mechanisms that come into play at much earlier level of learning and literacy development. The study outlines the development of ‘ways of being’, or social practices, surrounding learning in a marginalised community in Port Elizabeth, in the Eastern Cape, South Africa. This was achieved by means of critical ethnography and it is therefore qualitatively based. The study shows how social structures enable or constrain a child’s school readiness and how they then go on to support or impede progress in school where the language and literacy needed for educational success are further developed. The study therefore aims to allow us to explain global data indicating that the single greatest indicator of a young person’s ability to access and succeed in higher education is the level of education of caregivers in their homes of origin. Examined from a critical perspective (i.e. with a concern for social justice), this study has made use of a framework using social, psychological and linguistic theory and more, particularly, the work of sociologist Margaret Archer (1995, 1996, 2003). The study makes particular use of Archer’s ‘morphogenetic framework’ which allows for an analysis of the way structure and culture impact on a child’s development over time. As I was concerned that my own social status might impact on the understandings I developed as a critical ethnographer, the study acknowledges my own experiences of learning and the way my own family sought to enhance them as enabling. In doing this, the study aims to better contribute to understandings of social justice in South Africa.
- Full Text:
An analysis of the availability of and access to credit from the formal financial sector and the performance of SMEs
- Authors: Asah, Francis Tangwo
- Date: 2019
- Subjects: Small business -- South Africa -- Finance , Microfinance -- South Africa , South Africa -- Economic conditions -- 1991-
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/115138 , vital:34081
- Description: As a developing nation, South Africa faces a high rate of poverty, high levels of inequality in terms of income and a high rate of unemployment. It is officially estimated that about 27.2% of the economically active population are unemployed. SMEs are expected to be an important vehicle to address the challenges of job creation, sustainable economic growth, equitable distribution of income and the overall stimulation of economic development. SMEs in South Africa constitute 99% of all businesses, contributing to employment, income inequality and poverty alleviation (Statistic South Africa, 2018). However, despite the remarkable contribution of SMEs to the economy of South Africa, the failure rate of SMEs (at 75%) is the highest of all the efficiency-driven economies sampled by the Global Entrepreneurship Monitor (GEM). The World Bank affirm that the availability of and access to credit from the formal financial sector is the primary cause of the high failure rate of SMEs. Contemporary literature advance that the future survival and performance of SMEs in South Africa is pegged onto the amount of financial capital available to address their capital needs. Thus, this study sought to analyse the availability of and access to credit from the formal financial sector and the performance of SMEs from the supply and demand-side. In order to achieve the objectives of the study, a sequential exploratory mixed method research design, located in the pragmatic research paradigm, was used in a two phased approach. The qualitative data collection and analysis in Phase 1 informed the quantitative data collection and analysis Phase 2. In Phase 1, in-depth face-to-face semi-structured interviews were conducted with 8 credit and 8 business managers representing the sampling unit of selected formal financial institutions. The qualitative data collected was analysed using the five-steps process of content analysis as illustrated by Terre Blanche et al. (2006:322-326). The main findings with regard to factors that impact on the willingness of the formal financial sector to provide credit to SMEs were collateral, annual business turnover, audited financial records, relationship with the bank, credit profile, nature of the business, economic climate, ethics, nationality, government policy, management team, valid Identity Document/permit, equity contribution, entrepreneurship education, product quality, and business intelligence. Assessing credit applications from SMEs, risk assessment, inspection of financial records, proper documentation and background checks were the different tasks performed by credit and business managers. In addition, the main challenges faced by the formal financial sector in assessing and approving credit in favour of SMEs included the following: lack of investment capital; lack of collateral; lack of proper financial records; poor managerial knowledge; poor business plan; lack of industrial knowledge; and poor legal and credit laws. Lastly, contrary to the notion that formal financial institutions are not interested in investing in SMEs, on average, 70% of SMEs that applied for credit received such credit. In Phase 2, a self-administered questionnaire was used to collect data from formal sector owner/managers of SMEs in the city of Johannesburg. Of the 702 questionnaires distributed, 300 were returned and useable. Data was analysed using the Statistical Package for the Social Sciences (version 24). A test for normality was performed using Shapiro–Wilks test. Reliability was tested using the Cronbach’s Alpha Coefficient. Exploratory factor analysis tested the validity of factors that prevent formal financial sector from granting credit to SMEs while Binary logistic regression was used to infer on the hypotheses. Spearman’s Rho correlation analysis was used to determine whether there was any significant relationship with factors that influence access to credit and SMEs performance. The main findings revealed that access to bank finance was the only challenge that showed a significant correlation with performance. In addition, the study revealed that the South African Identity Document and collateral were the most important factors considered when applying for credit from formal financial institutions. With regard to the reasons why formal financial institutions may refuse to grant credit to SMEs, it was revealed that there was no significant positive relationship between lack of business networking and access to credit from the formal financial sector to SMEs. Conversely, the study also revealed a significant positive relationship between collateral, business information, managerial competency, business intelligence, business ethics, entrepreneurship education, legal system and macro-economy and access to credit from the formal financial sector to SMEs. Thus, it was established that there is a significant positive relationship between access to credit from the formal financial sector and the performance of SMEs.
- Full Text:
- Authors: Asah, Francis Tangwo
- Date: 2019
- Subjects: Small business -- South Africa -- Finance , Microfinance -- South Africa , South Africa -- Economic conditions -- 1991-
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/115138 , vital:34081
- Description: As a developing nation, South Africa faces a high rate of poverty, high levels of inequality in terms of income and a high rate of unemployment. It is officially estimated that about 27.2% of the economically active population are unemployed. SMEs are expected to be an important vehicle to address the challenges of job creation, sustainable economic growth, equitable distribution of income and the overall stimulation of economic development. SMEs in South Africa constitute 99% of all businesses, contributing to employment, income inequality and poverty alleviation (Statistic South Africa, 2018). However, despite the remarkable contribution of SMEs to the economy of South Africa, the failure rate of SMEs (at 75%) is the highest of all the efficiency-driven economies sampled by the Global Entrepreneurship Monitor (GEM). The World Bank affirm that the availability of and access to credit from the formal financial sector is the primary cause of the high failure rate of SMEs. Contemporary literature advance that the future survival and performance of SMEs in South Africa is pegged onto the amount of financial capital available to address their capital needs. Thus, this study sought to analyse the availability of and access to credit from the formal financial sector and the performance of SMEs from the supply and demand-side. In order to achieve the objectives of the study, a sequential exploratory mixed method research design, located in the pragmatic research paradigm, was used in a two phased approach. The qualitative data collection and analysis in Phase 1 informed the quantitative data collection and analysis Phase 2. In Phase 1, in-depth face-to-face semi-structured interviews were conducted with 8 credit and 8 business managers representing the sampling unit of selected formal financial institutions. The qualitative data collected was analysed using the five-steps process of content analysis as illustrated by Terre Blanche et al. (2006:322-326). The main findings with regard to factors that impact on the willingness of the formal financial sector to provide credit to SMEs were collateral, annual business turnover, audited financial records, relationship with the bank, credit profile, nature of the business, economic climate, ethics, nationality, government policy, management team, valid Identity Document/permit, equity contribution, entrepreneurship education, product quality, and business intelligence. Assessing credit applications from SMEs, risk assessment, inspection of financial records, proper documentation and background checks were the different tasks performed by credit and business managers. In addition, the main challenges faced by the formal financial sector in assessing and approving credit in favour of SMEs included the following: lack of investment capital; lack of collateral; lack of proper financial records; poor managerial knowledge; poor business plan; lack of industrial knowledge; and poor legal and credit laws. Lastly, contrary to the notion that formal financial institutions are not interested in investing in SMEs, on average, 70% of SMEs that applied for credit received such credit. In Phase 2, a self-administered questionnaire was used to collect data from formal sector owner/managers of SMEs in the city of Johannesburg. Of the 702 questionnaires distributed, 300 were returned and useable. Data was analysed using the Statistical Package for the Social Sciences (version 24). A test for normality was performed using Shapiro–Wilks test. Reliability was tested using the Cronbach’s Alpha Coefficient. Exploratory factor analysis tested the validity of factors that prevent formal financial sector from granting credit to SMEs while Binary logistic regression was used to infer on the hypotheses. Spearman’s Rho correlation analysis was used to determine whether there was any significant relationship with factors that influence access to credit and SMEs performance. The main findings revealed that access to bank finance was the only challenge that showed a significant correlation with performance. In addition, the study revealed that the South African Identity Document and collateral were the most important factors considered when applying for credit from formal financial institutions. With regard to the reasons why formal financial institutions may refuse to grant credit to SMEs, it was revealed that there was no significant positive relationship between lack of business networking and access to credit from the formal financial sector to SMEs. Conversely, the study also revealed a significant positive relationship between collateral, business information, managerial competency, business intelligence, business ethics, entrepreneurship education, legal system and macro-economy and access to credit from the formal financial sector to SMEs. Thus, it was established that there is a significant positive relationship between access to credit from the formal financial sector and the performance of SMEs.
- Full Text:
Understanding the learning that occurs through up-skilling opportunities and practices in the marine sector of South Africa
- Authors: Bell, Caroline Margaret
- Date: 2019
- Subjects: Biodiversity conservation -- South Africa , Human capital -- South Africa , Marine sciences -- Employees -- South Africa -- Training of , Biodiversity Human Capital Development Strategy (South Africa)
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/93966 , vital:30977
- Description: South Africa is characterised by cultural and biological diversity which constitute a unique context in which to conduct educational research, such as this doctoral study looking at human capital development in the marine biodiversity context. The drive for transformation in the country is also a major factor to consider when researching any sector of the economy, in this case, the biodiversity sector. The biodiversity sector includes organisations involved in biodiversity conservation, research and management. Previous research in the sector has found a clear need for well-thought out workplace skills plans within conservation and research organisations. The national Biodiversity Human Capital Development Strategy that was produced in 2010 by the South African National Biodiversity Institute outlines how all the organisations involved in the biodiversity sector of South Africa need to participate in strengthening the sector through a range of human capital development strategies. This includes extending the existing human capacity of managers and scientists who are already in the workplace, i.e. up-skilling. In particular, ‘scarce’ skills, as identified by the national Environmental Sector Skills Plan need further attention and development. The scarce skills relevant to this study are: protected area managers; ecosystem managers and post-graduate researchers, hence the focus on managers and scientists in this research. The marine sector falls within the biodiversity sector and it faces multiple conservation challenges which are complex and it is therefore essential to have skilled and capable managers and scientists in place. By investigating the up-skilling opportunities and practices available to these marine professionals, the goal is to understand if and how learning takes place in the marine sector of South Africa. The main research question of this study is: How do up-skilling opportunities and practices enable learning in, through and for the workplace, by marine professionals? In addition, three sub-questions provide finer details and introduce the central concepts of the research: I. What up-skilling opportunities and professional practices exist in or for, marine research and conservation organisations and how are they constituted and enacted via practice-based sayings, doings and relatings? II. How do the individuals learn and exercise their agency within the socio-material realities of the marine scientific and management context, through making use of up-skilling opportunities that are both formal (e.g. course based) and informal? III. How do generative mechanisms shape the constitution and enactment of up-skilling opportunities and practices, and the learning and agency of marine professionals (scientists and managers)? The theoretical work of this study consisted of, first, considering sensitising concepts which included: defining skill and knowledge; considering what an up-skilling opportunity might look like; workplace learning (both formal and informal learning); professional practices, lifelong learning or adult education, and agency in the workplace. Critical realism was then employed as the meta-theory that underlabours this research, while the substantive theories used for analysis purposes were socio-materialism and practice theory. Of course, critical realism is a socio-material theory itself, and Bhaskar’s four-planar social being or Social Cube was used to interpret and synthesise the findings in the data chapters. The methodological framework of this study explores the implications of critical realism for research design and analysis and includes a contextual profiling phase, semi-structured interviews, analysis of documents and peer-reviewed papers, as well as observations. There are nine case studies that form the focus of this research and in total 18 research participants were involved. Data analysis included abduction and retroduction as the primary modes of inference and the main analytical tool was the framework of practice architectures where I took the ‘sayings’, ‘doings’ and ‘relatings’ as themes. Further themes were developed from the other relevant theories used in this study; hence socio-materialism, learning, agency, and formal and informal opportunities, were also used as themes when coding the data. Issues around validity, ethics and reflexivity are key elements of the research design and were carefully considered throughout the research process. The principal data chapters are structured in such a way that each sub-question is considered and ultimately the findings are presented in the form of generative mechanisms which included: the politics of social transformation and knowledge as a driving force of up-skilling; the influence of individual disposition and passion or will; the importance of the socio-material realities and realistic expectations; and how relationality is critical for the marine sector. Agency was a cross-cutting theme in all the discussions around learning, practices and the role of the material, and was highly influential on the mechanisms that have been described in this study. The experiences, events and mechanisms that were uncovered in this research provide insight into the forms of learning as these relate to up-skilling that occur in the marine sector, as well as the complex relationships between formal and informal learning. The professional practices that occur in the everyday working lives of the marine professionals were shown to be an integral part of the learning process, while formal, certified opportunities are important for strengthening the field and building conservation competence in the country. By uncovering the deeper structures and mechanisms that have power and causal efficacy when it comes to up-skilling opportunities, learning and professional practices, this study has contributed to the field of environmental education as it shows how up-skilling processes operate in complex formations that involve formal and informal learning processes in workplaces. The study also offers a more nuanced view of the relational objects in this field, such as up-skilling and workplace learning, via the inclusion of a socio-material analysis. Through a theoretical and methodological framework that focused on the material using the tools of practice theory and Bhaskar’s depth ontology and four-planar social being (to synthesise and interpret the findings from a critical realist perspective), this research highlights the unique context of up-skilling opportunities and practices in the marine sector and reveals the crucial role of agency in workplace practices. This leads to a better understanding of the up-skilling opportunities and practices of marine professionals in South Africa, which ultimately contributes towards improved human capital development in the biodiversity and environmental sectors. Through offering more complex insights into the forms of learning and up-skilling, as well as a distinct methodological contribution, this research has broader relevance for workplace learning research.
- Full Text:
- Authors: Bell, Caroline Margaret
- Date: 2019
- Subjects: Biodiversity conservation -- South Africa , Human capital -- South Africa , Marine sciences -- Employees -- South Africa -- Training of , Biodiversity Human Capital Development Strategy (South Africa)
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/93966 , vital:30977
- Description: South Africa is characterised by cultural and biological diversity which constitute a unique context in which to conduct educational research, such as this doctoral study looking at human capital development in the marine biodiversity context. The drive for transformation in the country is also a major factor to consider when researching any sector of the economy, in this case, the biodiversity sector. The biodiversity sector includes organisations involved in biodiversity conservation, research and management. Previous research in the sector has found a clear need for well-thought out workplace skills plans within conservation and research organisations. The national Biodiversity Human Capital Development Strategy that was produced in 2010 by the South African National Biodiversity Institute outlines how all the organisations involved in the biodiversity sector of South Africa need to participate in strengthening the sector through a range of human capital development strategies. This includes extending the existing human capacity of managers and scientists who are already in the workplace, i.e. up-skilling. In particular, ‘scarce’ skills, as identified by the national Environmental Sector Skills Plan need further attention and development. The scarce skills relevant to this study are: protected area managers; ecosystem managers and post-graduate researchers, hence the focus on managers and scientists in this research. The marine sector falls within the biodiversity sector and it faces multiple conservation challenges which are complex and it is therefore essential to have skilled and capable managers and scientists in place. By investigating the up-skilling opportunities and practices available to these marine professionals, the goal is to understand if and how learning takes place in the marine sector of South Africa. The main research question of this study is: How do up-skilling opportunities and practices enable learning in, through and for the workplace, by marine professionals? In addition, three sub-questions provide finer details and introduce the central concepts of the research: I. What up-skilling opportunities and professional practices exist in or for, marine research and conservation organisations and how are they constituted and enacted via practice-based sayings, doings and relatings? II. How do the individuals learn and exercise their agency within the socio-material realities of the marine scientific and management context, through making use of up-skilling opportunities that are both formal (e.g. course based) and informal? III. How do generative mechanisms shape the constitution and enactment of up-skilling opportunities and practices, and the learning and agency of marine professionals (scientists and managers)? The theoretical work of this study consisted of, first, considering sensitising concepts which included: defining skill and knowledge; considering what an up-skilling opportunity might look like; workplace learning (both formal and informal learning); professional practices, lifelong learning or adult education, and agency in the workplace. Critical realism was then employed as the meta-theory that underlabours this research, while the substantive theories used for analysis purposes were socio-materialism and practice theory. Of course, critical realism is a socio-material theory itself, and Bhaskar’s four-planar social being or Social Cube was used to interpret and synthesise the findings in the data chapters. The methodological framework of this study explores the implications of critical realism for research design and analysis and includes a contextual profiling phase, semi-structured interviews, analysis of documents and peer-reviewed papers, as well as observations. There are nine case studies that form the focus of this research and in total 18 research participants were involved. Data analysis included abduction and retroduction as the primary modes of inference and the main analytical tool was the framework of practice architectures where I took the ‘sayings’, ‘doings’ and ‘relatings’ as themes. Further themes were developed from the other relevant theories used in this study; hence socio-materialism, learning, agency, and formal and informal opportunities, were also used as themes when coding the data. Issues around validity, ethics and reflexivity are key elements of the research design and were carefully considered throughout the research process. The principal data chapters are structured in such a way that each sub-question is considered and ultimately the findings are presented in the form of generative mechanisms which included: the politics of social transformation and knowledge as a driving force of up-skilling; the influence of individual disposition and passion or will; the importance of the socio-material realities and realistic expectations; and how relationality is critical for the marine sector. Agency was a cross-cutting theme in all the discussions around learning, practices and the role of the material, and was highly influential on the mechanisms that have been described in this study. The experiences, events and mechanisms that were uncovered in this research provide insight into the forms of learning as these relate to up-skilling that occur in the marine sector, as well as the complex relationships between formal and informal learning. The professional practices that occur in the everyday working lives of the marine professionals were shown to be an integral part of the learning process, while formal, certified opportunities are important for strengthening the field and building conservation competence in the country. By uncovering the deeper structures and mechanisms that have power and causal efficacy when it comes to up-skilling opportunities, learning and professional practices, this study has contributed to the field of environmental education as it shows how up-skilling processes operate in complex formations that involve formal and informal learning processes in workplaces. The study also offers a more nuanced view of the relational objects in this field, such as up-skilling and workplace learning, via the inclusion of a socio-material analysis. Through a theoretical and methodological framework that focused on the material using the tools of practice theory and Bhaskar’s depth ontology and four-planar social being (to synthesise and interpret the findings from a critical realist perspective), this research highlights the unique context of up-skilling opportunities and practices in the marine sector and reveals the crucial role of agency in workplace practices. This leads to a better understanding of the up-skilling opportunities and practices of marine professionals in South Africa, which ultimately contributes towards improved human capital development in the biodiversity and environmental sectors. Through offering more complex insights into the forms of learning and up-skilling, as well as a distinct methodological contribution, this research has broader relevance for workplace learning research.
- Full Text:
Statistical Analysis of the Radio-Interferometric Measurement Equation, a derived adaptive weighting scheme, and applications to LOFAR-VLBI observation of the Extended Groth Strip
- Authors: Bonnassieux, Etienne
- Date: 2019
- Subjects: Radio astronomy , Astrophysics , Astrophysics -- Instruments -- Calibration , Imaging systems in astronomy , Radio interferometers , Radio telescopes , Astronomy -- Observations
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/93789 , vital:30942
- Description: J.R.R Tolkien wrote, in his Mythopoeia, that “He sees no stars who does not see them first, of living silver made that sudden burst, to flame like flowers beneath the ancient song”. In his defense of myth-making, he formulates the argument that the attribution of meaning is an act of creation - that “trees are not ‘trees’ until so named and seen” - and that this capacity for creation defines the human creature. The scientific endeavour, in this context, can be understood as a social expression of a fundamental feature of humanity, and from this endeavour flows much understanding. This thesis, one thread among many, focuses on the study of astronomical objects as seen by the radio waves they emit. What are radio waves? Electromagnetic waves were theorised by James Clerk Maxwell (Maxwell 1864) in his great theoretical contribution to modern physics, their speed matching the speed of light as measured by Ole Christensen R0mer and, later, James Bradley. It was not until Heinrich Rudolf Hertz’s 1887 experiment that these waves were measured in a laboratory, leading to the dawn of radio communications - and, later, radio astronomy. The link between radio waves and light was one of association: light is known to behave as a wave (Young double-slit experiment), with the same propagation speed as electromagnetic radiation. Light “proper” is also known to exist beyond the optical regime: Herschel’s experiment shows that when diffracted through a prism, sunlight warms even those parts of a desk which are not observed to be lit (first evidence of infrared light). The link between optical light and unseen electromagnetic radiation is then an easy step to make, and one confirmed through countless technological applications (e.g. optical fiber to name but one). And as soon as this link is established, a question immediately comes to the mind of the astronomer: what does the sky, our Universe, look like to the radio “eye”? Radio astronomy has a short but storied history: from Karl Jansky’s serendipitous observation of the centre of the Milky Way, which outshines our Sun in the radio regime, in 1933, to Grote Reber’s hand-built back-yard radio antenna in 1937, which successfully detected radio emission from the Milky Way itself, to such monumental projects as the Square Kilometer Array and its multiple pathfinders, it has led to countless discoveries and the opening of a truly new window on the Universe. The work presented in this thesis is a contribution to this discipline - the culmination of three years of study, which is a rather short time to get a firm grasp of radio interferometry both in theory and in practice. The need for robust, automated methods - which are improving daily, thanks to the tireless labour of the scientists in the field - is becoming ever stronger as the SKA approaches, looming large on the horizon; but even today, in the precursor era of LOFAR, MeerKAT and other pathfinders, it is keenly felt. When I started my doctorate, the sheer scale of the task at hand felt overwhelming - to actually be able to contribute to its resolution seemed daunting indeed! Thankfully, as the saying goes, no society sets for itself material goals which it cannot achieve. This thesis took place at an exciting time for radio interferometry: at the start of my doctorate, the LOFAR international stations were - to my knowledge - only beginning to be used, and even then, only tentatively; MeerKAT had not yet shown its first light; the techniques used throughout my work were still being developed. At the time of writing, great strides have been made. One of the greatest technical challenges of LOFAR - imaging using the international stations - is starting to become reality. This technical challenge is the key problem that this thesis set out to address. While we only achieved partial success so far, it is a testament to the difficulty of the task that it is not yet truly resolved. One of the major results of this thesis is a model of a bright resolved source near a famous extragalactic field: properly modeling this source not only allows the use of international LOFAR stations, but also grants deeper access to the extragalactic field itself, which is otherwise polluted by the 3C source’s sidelobes. This result was only achieved thanks to the other major result of this thesis: the development of a theoretical framework with which to better understand the effect of calibration errors on images made from interferometric data, and an algorithm to strongly mitigate them. The structure of this manuscript is as follows: we begin with an introduction to radio interferometry, LOFAR, and the emission mechanisms which dominate for our field of interest. These introductions are primarily intended to give a brief overview of the technical aspects of the data reduced in this thesis. We follow with an overview of the Measurement Equation formalism, which underpins our theoretical work. This is the keystone of this thesis. We then show the theoretical work that was developed as part of the research work done during the doctorate - which was published in Astronomy & Astrophysics. Its practical application - a quality-based weighting scheme - is used throughout our data reduction. This data reduction is the next topic of this thesis: we contextualise the scientific interest of the data we reduce, and explain both the methods and the results we achieve.
- Full Text:
- Authors: Bonnassieux, Etienne
- Date: 2019
- Subjects: Radio astronomy , Astrophysics , Astrophysics -- Instruments -- Calibration , Imaging systems in astronomy , Radio interferometers , Radio telescopes , Astronomy -- Observations
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/93789 , vital:30942
- Description: J.R.R Tolkien wrote, in his Mythopoeia, that “He sees no stars who does not see them first, of living silver made that sudden burst, to flame like flowers beneath the ancient song”. In his defense of myth-making, he formulates the argument that the attribution of meaning is an act of creation - that “trees are not ‘trees’ until so named and seen” - and that this capacity for creation defines the human creature. The scientific endeavour, in this context, can be understood as a social expression of a fundamental feature of humanity, and from this endeavour flows much understanding. This thesis, one thread among many, focuses on the study of astronomical objects as seen by the radio waves they emit. What are radio waves? Electromagnetic waves were theorised by James Clerk Maxwell (Maxwell 1864) in his great theoretical contribution to modern physics, their speed matching the speed of light as measured by Ole Christensen R0mer and, later, James Bradley. It was not until Heinrich Rudolf Hertz’s 1887 experiment that these waves were measured in a laboratory, leading to the dawn of radio communications - and, later, radio astronomy. The link between radio waves and light was one of association: light is known to behave as a wave (Young double-slit experiment), with the same propagation speed as electromagnetic radiation. Light “proper” is also known to exist beyond the optical regime: Herschel’s experiment shows that when diffracted through a prism, sunlight warms even those parts of a desk which are not observed to be lit (first evidence of infrared light). The link between optical light and unseen electromagnetic radiation is then an easy step to make, and one confirmed through countless technological applications (e.g. optical fiber to name but one). And as soon as this link is established, a question immediately comes to the mind of the astronomer: what does the sky, our Universe, look like to the radio “eye”? Radio astronomy has a short but storied history: from Karl Jansky’s serendipitous observation of the centre of the Milky Way, which outshines our Sun in the radio regime, in 1933, to Grote Reber’s hand-built back-yard radio antenna in 1937, which successfully detected radio emission from the Milky Way itself, to such monumental projects as the Square Kilometer Array and its multiple pathfinders, it has led to countless discoveries and the opening of a truly new window on the Universe. The work presented in this thesis is a contribution to this discipline - the culmination of three years of study, which is a rather short time to get a firm grasp of radio interferometry both in theory and in practice. The need for robust, automated methods - which are improving daily, thanks to the tireless labour of the scientists in the field - is becoming ever stronger as the SKA approaches, looming large on the horizon; but even today, in the precursor era of LOFAR, MeerKAT and other pathfinders, it is keenly felt. When I started my doctorate, the sheer scale of the task at hand felt overwhelming - to actually be able to contribute to its resolution seemed daunting indeed! Thankfully, as the saying goes, no society sets for itself material goals which it cannot achieve. This thesis took place at an exciting time for radio interferometry: at the start of my doctorate, the LOFAR international stations were - to my knowledge - only beginning to be used, and even then, only tentatively; MeerKAT had not yet shown its first light; the techniques used throughout my work were still being developed. At the time of writing, great strides have been made. One of the greatest technical challenges of LOFAR - imaging using the international stations - is starting to become reality. This technical challenge is the key problem that this thesis set out to address. While we only achieved partial success so far, it is a testament to the difficulty of the task that it is not yet truly resolved. One of the major results of this thesis is a model of a bright resolved source near a famous extragalactic field: properly modeling this source not only allows the use of international LOFAR stations, but also grants deeper access to the extragalactic field itself, which is otherwise polluted by the 3C source’s sidelobes. This result was only achieved thanks to the other major result of this thesis: the development of a theoretical framework with which to better understand the effect of calibration errors on images made from interferometric data, and an algorithm to strongly mitigate them. The structure of this manuscript is as follows: we begin with an introduction to radio interferometry, LOFAR, and the emission mechanisms which dominate for our field of interest. These introductions are primarily intended to give a brief overview of the technical aspects of the data reduced in this thesis. We follow with an overview of the Measurement Equation formalism, which underpins our theoretical work. This is the keystone of this thesis. We then show the theoretical work that was developed as part of the research work done during the doctorate - which was published in Astronomy & Astrophysics. Its practical application - a quality-based weighting scheme - is used throughout our data reduction. This data reduction is the next topic of this thesis: we contextualise the scientific interest of the data we reduce, and explain both the methods and the results we achieve.
- Full Text:
Towards a norm of compliance in recreational fisheries
- Authors: Bova, Christopher S
- Date: 2019
- Subjects: Fishing -- Management -- South Africa , Fishery law and legislation -- South Africa
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/95909 , vital:31213
- Description: The activity of fishing can be traced back to prehistoric times. However, only in the last century has there been a focus on the management of fisheries. Fishery regulations are tools used by resource managers with the aim of protecting the long-term sustainability of fishery resources. Although there is an overwhelming amount of evidence demonstrating the decline of fisheries, non-compliance with these regulations by fishers continues to manifest, which can exacerbate the negative ecological impacts of fisheries. Popular methods towards the measurement of noncompliance in fisheries derived from previous human dimensions literature may be flawed. Theories on improving compliance behaviour have typically relied on theory, which has at times proved paradoxical. Addressing the issues of non-compliance within a fishery of interest requires measuring the levels of non-compliance within the fishery and determining the relevant sociopsychological drivers behind the non-compliant behaviour. The data collection methods used during these assessments are limited in human dimensions research and are often case and context specific, requiring researchers to identify which approach is most practical for the specific fishery of interest. By identifying relevant behavioural drivers of non-compliance, a more effective approach aimed at improving compliance can be tailored. The recreational marine-based shore fishery (MBSF) in South Africa is not impervious to noncomplaint behaviour. In fact, it has been estimated to have relatively high rates of non-compliance. This high level of non-compliance makes the South African MBSF a unique and optimal context in which to undertake research that aims to formulate a framework towards compliance assessments and that develops a suitable approach for improving compliance rates. Using surveys to obtain compliance data can provide a range of details about violators, however they are susceptible to social desirability bias (SDB). Choosing the best method for controlling SDB required an assessment of existing methods for doing so. In this first part of the study, only fishers who were covertly observed breaking the rules were surveyed, using one of three methods for reducing SDB, to ground-truth the responses. Ground-truthing was done to determine which method would be most effective for a large-scale study within the same fishery. Of the methods used, which include the direct questioning method (DQM), the random response technique (RRT) and the ballot box method (BBM), all contained some level of SDB. However, the BBM provided a significantly higher level of response accuracy (79.6% ± 11.9) than the DQM (46.5% ± 14.9) and the RRT (44.3% ± 12.5). Random-stratified roving creel compliance surveys that employed the BBM were then undertaken at various locations along South Africa’s coastline to estimate current rates of non-compliance, and the face-to-face results were compared to results from an identical online survey to determine the suitability of online surveys as a replacement. The results indicated that online surveys only represent a subgroup of the fisher population within the MBSF, suggesting that face-to-face survey methods are required to obtain a more comprehensive sample and a more robust estimate of noncompliance. The results, based on 453 face-to-face surveys, showed a high level of overall self-reported noncompliance (48.3%) within the fishery. Responses to Likert scale survey questions on various aspects of the fishery, including angler motivations for fishing, were then modelled to test the relationship between the anglers’ responses and their compliance behaviour. In the South African MBSF context, the most significant behavioural drivers behind non-compliance related to normative concepts. Specifically, the poor perceptions of management and value-based legitimacy as well as low levels of moral obligation to adhere to the regulations appeared to contribute most to the observed non-compliant behaviour. Angler motivations for fishing also played a significant role in determining the compliance behaviour of anglers, with those fishing for food being more likely to violate regulations. In most countries, regardless of economic context, interventions to improve recreational fishery compliance have been developed around the instrumental concept. However, these findings suggest that for recreational fisheries, managers would do well to evaluate the impact of normative concepts on compliance and to design interventions aimed at addressing these. In the case of the South African MBSF, interventions that address angler perceptions of legitimacy and aim to correct misperceptions about social norms of compliance may provide a more practical and cost- effective method for improving poor compliance behaviour.
- Full Text:
- Authors: Bova, Christopher S
- Date: 2019
- Subjects: Fishing -- Management -- South Africa , Fishery law and legislation -- South Africa
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/95909 , vital:31213
- Description: The activity of fishing can be traced back to prehistoric times. However, only in the last century has there been a focus on the management of fisheries. Fishery regulations are tools used by resource managers with the aim of protecting the long-term sustainability of fishery resources. Although there is an overwhelming amount of evidence demonstrating the decline of fisheries, non-compliance with these regulations by fishers continues to manifest, which can exacerbate the negative ecological impacts of fisheries. Popular methods towards the measurement of noncompliance in fisheries derived from previous human dimensions literature may be flawed. Theories on improving compliance behaviour have typically relied on theory, which has at times proved paradoxical. Addressing the issues of non-compliance within a fishery of interest requires measuring the levels of non-compliance within the fishery and determining the relevant sociopsychological drivers behind the non-compliant behaviour. The data collection methods used during these assessments are limited in human dimensions research and are often case and context specific, requiring researchers to identify which approach is most practical for the specific fishery of interest. By identifying relevant behavioural drivers of non-compliance, a more effective approach aimed at improving compliance can be tailored. The recreational marine-based shore fishery (MBSF) in South Africa is not impervious to noncomplaint behaviour. In fact, it has been estimated to have relatively high rates of non-compliance. This high level of non-compliance makes the South African MBSF a unique and optimal context in which to undertake research that aims to formulate a framework towards compliance assessments and that develops a suitable approach for improving compliance rates. Using surveys to obtain compliance data can provide a range of details about violators, however they are susceptible to social desirability bias (SDB). Choosing the best method for controlling SDB required an assessment of existing methods for doing so. In this first part of the study, only fishers who were covertly observed breaking the rules were surveyed, using one of three methods for reducing SDB, to ground-truth the responses. Ground-truthing was done to determine which method would be most effective for a large-scale study within the same fishery. Of the methods used, which include the direct questioning method (DQM), the random response technique (RRT) and the ballot box method (BBM), all contained some level of SDB. However, the BBM provided a significantly higher level of response accuracy (79.6% ± 11.9) than the DQM (46.5% ± 14.9) and the RRT (44.3% ± 12.5). Random-stratified roving creel compliance surveys that employed the BBM were then undertaken at various locations along South Africa’s coastline to estimate current rates of non-compliance, and the face-to-face results were compared to results from an identical online survey to determine the suitability of online surveys as a replacement. The results indicated that online surveys only represent a subgroup of the fisher population within the MBSF, suggesting that face-to-face survey methods are required to obtain a more comprehensive sample and a more robust estimate of noncompliance. The results, based on 453 face-to-face surveys, showed a high level of overall self-reported noncompliance (48.3%) within the fishery. Responses to Likert scale survey questions on various aspects of the fishery, including angler motivations for fishing, were then modelled to test the relationship between the anglers’ responses and their compliance behaviour. In the South African MBSF context, the most significant behavioural drivers behind non-compliance related to normative concepts. Specifically, the poor perceptions of management and value-based legitimacy as well as low levels of moral obligation to adhere to the regulations appeared to contribute most to the observed non-compliant behaviour. Angler motivations for fishing also played a significant role in determining the compliance behaviour of anglers, with those fishing for food being more likely to violate regulations. In most countries, regardless of economic context, interventions to improve recreational fishery compliance have been developed around the instrumental concept. However, these findings suggest that for recreational fisheries, managers would do well to evaluate the impact of normative concepts on compliance and to design interventions aimed at addressing these. In the case of the South African MBSF, interventions that address angler perceptions of legitimacy and aim to correct misperceptions about social norms of compliance may provide a more practical and cost- effective method for improving poor compliance behaviour.
- Full Text:
Occurrence, feeding ecology, and population structure of two dolphin species, Tursiops aduncus and Delphinus delphis, off the Wild Coast of South Africa
- Authors: Caputo, Michelle Anne
- Date: 2019
- Subjects: Delphinus -- South Africa-- Kwazulu-Natal -- Ecology , Tursoops -- South Africa-- Kwazulu-Natal -- Ecology , Delphinus -- South Africa-- Kwazulu-Natal -- Feeding and feeds , Tursoops -- South Africa-- Kwazulu-Natal -- Feeding and feeds , Dolphins -- South Africa-- Kwazulu-Natal , Delphinus -- South Africa-- Kwazulu-Natal -- Behavior , Tursoops -- South Africa-- Kwazulu-Natal -- Behavior , Marine ecology -- South Africa -- Kwazulu-Natal
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/115612 , vital:34197
- Description: Dolphins are apex predators and their movements, foraging activities and population dynamics play an important role in shaping their environment. Understanding their occurrence, movement patterns, and trophic ecology is essential to their conservation, especially as they are considered sentinel species. The Wild Coast of South Africa’s Eastern Cape, is characterized by the annual sardine (Sardinops sagax) run, which serves as an important foraging event for apex predators, including Indo-Pacific bottlenose (Tursiops aduncus) and long-beaked common dolphins (Delphinus delphis). Despite the ecological significance of this event, no dedicated surveys for these species have previously been conducted in this area. The main objectives of this research were to: investigate long-term occurrence of dolphins during the sardine run to determine if there have been any changes over the past 19 years, as has been predicted from common dolphin dietary investigations and anecdotal evidence; to determine short-term occurrence and movement patterns of selected inshore delphinids within the area, which is characterized by three marine protected areas (MPAs); and to use stable isotope analyses to determine trophic relationships and population structure of bottlenose and common dolphins within the region. Long-term data consisted of 131 opportunistic aerial surveys conducted between May and July over the period 1996 to 2014. Results from these surveys indicate that common dolphins, typically associated with sardines, decreased significantly in average group size over the study period (p=0.0343). Bottlenose dolphins, demonstrated no such trend (p=0.916). For both species, greater majority (> 70% of total counts) of sightings were made inside the MPAs. Short-term boat-based surveys were conducted three times a year between June 2014 and December 2016, contributing to a total of 47 days of surveys divided into three locations: Amathole, Hluleka, and Pondoland, each containing a MPA. Density and group size data were analyzed for both species and photographic identification analysis was performed for photographs of bottlenose dolphin dorsal fins. Results indicate that animal and sighting density did not differ temporally (bottlenose dolphin: sighting density – p=0.398, individual density –p=0.781; common dolphin: sighting density –p=0.472, individual density – p=0.204). Environmental factors (sea surface temperature, depth, substrate, and distance from shore) appeared to have limited effect on individual and sighting density and group size for both species (p>0.05). Photographic identification of bottlenose dolphins resulted in 2149 individuals, with a 11.8% resighting rate, with the highest resighting rate within the Pondoland MPA (16.1%). The resighting count did not differ temporally between monthly survey based on generalized linear models (p=0.866), but did differ between study areas (p<0.0001). These results provide the first evidence of the occurrence of both species of dolphin off the Wild Coast, as they were sighted in this region in all survey months. There was no trend in density based on temporal or environmental factors, which suggests other factors are influencing their occurrence. Resightings of bottlenose dolphins within the area suggest that there is some degree of residency, though the majority of animals were only sighted on a single occasion and there was no plateau in the discovery curve. A total of 256 biopsy samples (bottlenose dolphins =128; common dolphins=128) were collected during boat-based surveys. Bottlenose dolphin samples were also collected from adjacent areas to the southwest (Algoa Bay, n=22) and northeast (KwaZulu-Natal (KZN), n=20) of the Wild Coast to investigate similarities and differences between these areas. Despite a high degree of niche overlap between the two species (41%), common dolphins fed with a broader niche (standard ellipse area probability 0.89) than bottlenose dolphins in the summer and a narrower niche in the winter (probability 0.94). There was a clear spatial variation in the diet of bottlenose dolphins along the coast, with individuals from Algoa Bay and Amathole demonstrating 0% niche overlap with individuals from KZN, but the mechanism for these differences remains unclear as other species from South African waters demonstrate a strong southwest to northeast gradient in nitrogen for the Eastern Cape coastline. This research provides valuable baseline information regarding dolphins off the Wild Coast of South Africa, which remained largely unknown. My results indicate that bottlenose dolphins may be more resident in the Wild Coast than previous predicted, and confirm that common dolphins are highly mobile in this area.
- Full Text:
- Authors: Caputo, Michelle Anne
- Date: 2019
- Subjects: Delphinus -- South Africa-- Kwazulu-Natal -- Ecology , Tursoops -- South Africa-- Kwazulu-Natal -- Ecology , Delphinus -- South Africa-- Kwazulu-Natal -- Feeding and feeds , Tursoops -- South Africa-- Kwazulu-Natal -- Feeding and feeds , Dolphins -- South Africa-- Kwazulu-Natal , Delphinus -- South Africa-- Kwazulu-Natal -- Behavior , Tursoops -- South Africa-- Kwazulu-Natal -- Behavior , Marine ecology -- South Africa -- Kwazulu-Natal
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/115612 , vital:34197
- Description: Dolphins are apex predators and their movements, foraging activities and population dynamics play an important role in shaping their environment. Understanding their occurrence, movement patterns, and trophic ecology is essential to their conservation, especially as they are considered sentinel species. The Wild Coast of South Africa’s Eastern Cape, is characterized by the annual sardine (Sardinops sagax) run, which serves as an important foraging event for apex predators, including Indo-Pacific bottlenose (Tursiops aduncus) and long-beaked common dolphins (Delphinus delphis). Despite the ecological significance of this event, no dedicated surveys for these species have previously been conducted in this area. The main objectives of this research were to: investigate long-term occurrence of dolphins during the sardine run to determine if there have been any changes over the past 19 years, as has been predicted from common dolphin dietary investigations and anecdotal evidence; to determine short-term occurrence and movement patterns of selected inshore delphinids within the area, which is characterized by three marine protected areas (MPAs); and to use stable isotope analyses to determine trophic relationships and population structure of bottlenose and common dolphins within the region. Long-term data consisted of 131 opportunistic aerial surveys conducted between May and July over the period 1996 to 2014. Results from these surveys indicate that common dolphins, typically associated with sardines, decreased significantly in average group size over the study period (p=0.0343). Bottlenose dolphins, demonstrated no such trend (p=0.916). For both species, greater majority (> 70% of total counts) of sightings were made inside the MPAs. Short-term boat-based surveys were conducted three times a year between June 2014 and December 2016, contributing to a total of 47 days of surveys divided into three locations: Amathole, Hluleka, and Pondoland, each containing a MPA. Density and group size data were analyzed for both species and photographic identification analysis was performed for photographs of bottlenose dolphin dorsal fins. Results indicate that animal and sighting density did not differ temporally (bottlenose dolphin: sighting density – p=0.398, individual density –p=0.781; common dolphin: sighting density –p=0.472, individual density – p=0.204). Environmental factors (sea surface temperature, depth, substrate, and distance from shore) appeared to have limited effect on individual and sighting density and group size for both species (p>0.05). Photographic identification of bottlenose dolphins resulted in 2149 individuals, with a 11.8% resighting rate, with the highest resighting rate within the Pondoland MPA (16.1%). The resighting count did not differ temporally between monthly survey based on generalized linear models (p=0.866), but did differ between study areas (p<0.0001). These results provide the first evidence of the occurrence of both species of dolphin off the Wild Coast, as they were sighted in this region in all survey months. There was no trend in density based on temporal or environmental factors, which suggests other factors are influencing their occurrence. Resightings of bottlenose dolphins within the area suggest that there is some degree of residency, though the majority of animals were only sighted on a single occasion and there was no plateau in the discovery curve. A total of 256 biopsy samples (bottlenose dolphins =128; common dolphins=128) were collected during boat-based surveys. Bottlenose dolphin samples were also collected from adjacent areas to the southwest (Algoa Bay, n=22) and northeast (KwaZulu-Natal (KZN), n=20) of the Wild Coast to investigate similarities and differences between these areas. Despite a high degree of niche overlap between the two species (41%), common dolphins fed with a broader niche (standard ellipse area probability 0.89) than bottlenose dolphins in the summer and a narrower niche in the winter (probability 0.94). There was a clear spatial variation in the diet of bottlenose dolphins along the coast, with individuals from Algoa Bay and Amathole demonstrating 0% niche overlap with individuals from KZN, but the mechanism for these differences remains unclear as other species from South African waters demonstrate a strong southwest to northeast gradient in nitrogen for the Eastern Cape coastline. This research provides valuable baseline information regarding dolphins off the Wild Coast of South Africa, which remained largely unknown. My results indicate that bottlenose dolphins may be more resident in the Wild Coast than previous predicted, and confirm that common dolphins are highly mobile in this area.
- Full Text:
Expanding learning in clergy leadership formation in an Anglican Church Province in Southern Africa: a critical realist study
- Authors: Chinganga, Percy
- Date: 2019
- Subjects: Leadership -- Africa, Southern -- Religious aspects -- Christianity , Church management -- Africa, Southern , Critical realism , Educational leadership , Anglican Church of Southern Africa
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/92258 , vital:30704
- Description: The focus of this study was to investigate the kind of learning that happened when participants involved in clergy leadership formation programmes and activities in the Anglican Church of Southern Africa (ACSA) engaged in their responsibilities as a collective. Further, the research sought to explore collaborative and transforming practices in ACSA clergy leadership formation programmes and activities which could be expanded through learning. The study is premised on an investigation of the historical foundations of Christian leadership formation processes which sought to establish clergy leadership formation models relevant to ACSA (the context of the study) from inception (1848) to date (2017). This entailed investigating how the developments which have happened in the church from its inception in the New Testament times through the Medieval and Reformation periods, have contributed to the emergence of distinct Christian leadership formation models which have formed the basis of clergy leadership formation in ACSA. Accordingly, the study highlighted key issues relating to clergy leadership formation which are discernible in the different historical phases of the life and work of the church with the objective of establishing how ACSA, through expansive learning, could transform her current clergy leadership formation model(s) towards collaborative and transforming practices. The concept of expansive learning, drawn from Cultural Historical Activity Theory (CHAT), was used in the study as a methodological tool to create an environment where research participants (formators) from several dioceses would engage in collective work activities which would surface contradictions relating to how clergy leadership formation programmes and activities were understood and facilitated in ACSA. In response to the surfaced contradictions, the study engaged research participants in Change Laboratory Workshops whose goal was to transform the organisation (ACSA) in two particular ways: empowerment of participants (formators) with conceptual tools relevant to their responsibilities in clergy leadership formation programmes and activities in ACSA, and improvement of organisational cultural practices, that is, the manner in which ACSA ought to conceptualise, design, plan, facilitate and manage clergy leadership formation programmes and activities. The latter brought into the discourse the need for participants (formators) to select and employ methodologies, methods, approaches and resources relevant to the southern African context where ACSA is located even though the study also acknowledged the influence of other Anglican Church contexts on what happened at the local level. In order to decipher meaning out of investigated phenomena about clergy leadership formation in ACSA, the study employed the critical realist “underlabouring” philosophy advanced by theorists such as Bhaskar to surface underlying mechanisms that exist at the level of the “real” in order to understand the causes of particular events and experiences as they manifest in the “actual” and “empirical” domains of the world, ACSA in the case of the study. In particular, the study engaged critically the opinion deliberated by critical realists concerning the interplay between structure and agency in relation to the responsibilities of the research participants (formators) in ACSA clergy leadership formation programmes and activities. For instance, the study had an interest in investigating why bishops (principal formators in ACSA) exercised their episcopal authority in the manner they do and why individual formators were concerned about particular issues which relate to the facilitation of clergy leadership formation in ACSA (agential reflexivity/subjectivity). The study observed that, in the case of diocesan bishops, critical realists would argue that, by virtue of the authority which comes with their responsibilities (agency), they have the power to influence transformation of practices in clergy leadership formation in ACSA at any given point in time. The flip side of the discourse was also taken note of: that some bishops, for reasons known to themselves and their predecessors, are often reluctant to embrace new ideas relating to clergy leadership formation practices in their dioceses. Further, through critical realist lens, the study concluded that Canons, Vision and Mission statements, Acts, and structures such as Synod of Bishops, Provincial Synod, ABoTE, Cott, and TfM structurally shape ACSA, thus providing the organisation with a stable ontology which ought to direct, regulate and control the manner in which clergy leadership formation programmes and activities were conceptualised, designed, planned, facilitated and managed. As such, the study had an interest in establishing what would happen, in relation to clergy leadership formation practices in ACSA, when these structures would have been activated? Beyond that, in view of the goal of the study, it was enquired how expansive learning processes could be helpful in responding to the research findings towards exploring collaborative and transforming clergy leadership formation practices in ACSA. Drawing from the conceptual framework which was carved in the study on the basis of the theoretical tools (critical realism and educational leadership theory) and methodological tools (CHAT orientated concepts) undergirded by the Vygotskian theorisation of human consciousness development, the study concluded that clergy leadership formation is a collaborative activity which calls for the recognition, appreciation and utilisation of available expertise in ACSA and provision of a platform where participants (formators) could engage collectively on issues relating to their work with the objective of building each other up in knowledge and skills (expansive learning) towards realisation of the goals and objectives of the organisation. Diverse understandings (contradictions) of what needed to be prioritised in the facilitation of clergy leadership formation in ACSA would be considered as a positive rather than a negative. Ultimately, through the use of inductive, abductive and retroductive modes of inference, the study modelled a transforming, transformational, transformative, embodied and incarnational model of clergy leadership formation which ACSA could consider using in future deliberations on the object of study particularly in relation to the key research findings across the case studies which were used in the study.
- Full Text:
- Authors: Chinganga, Percy
- Date: 2019
- Subjects: Leadership -- Africa, Southern -- Religious aspects -- Christianity , Church management -- Africa, Southern , Critical realism , Educational leadership , Anglican Church of Southern Africa
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/92258 , vital:30704
- Description: The focus of this study was to investigate the kind of learning that happened when participants involved in clergy leadership formation programmes and activities in the Anglican Church of Southern Africa (ACSA) engaged in their responsibilities as a collective. Further, the research sought to explore collaborative and transforming practices in ACSA clergy leadership formation programmes and activities which could be expanded through learning. The study is premised on an investigation of the historical foundations of Christian leadership formation processes which sought to establish clergy leadership formation models relevant to ACSA (the context of the study) from inception (1848) to date (2017). This entailed investigating how the developments which have happened in the church from its inception in the New Testament times through the Medieval and Reformation periods, have contributed to the emergence of distinct Christian leadership formation models which have formed the basis of clergy leadership formation in ACSA. Accordingly, the study highlighted key issues relating to clergy leadership formation which are discernible in the different historical phases of the life and work of the church with the objective of establishing how ACSA, through expansive learning, could transform her current clergy leadership formation model(s) towards collaborative and transforming practices. The concept of expansive learning, drawn from Cultural Historical Activity Theory (CHAT), was used in the study as a methodological tool to create an environment where research participants (formators) from several dioceses would engage in collective work activities which would surface contradictions relating to how clergy leadership formation programmes and activities were understood and facilitated in ACSA. In response to the surfaced contradictions, the study engaged research participants in Change Laboratory Workshops whose goal was to transform the organisation (ACSA) in two particular ways: empowerment of participants (formators) with conceptual tools relevant to their responsibilities in clergy leadership formation programmes and activities in ACSA, and improvement of organisational cultural practices, that is, the manner in which ACSA ought to conceptualise, design, plan, facilitate and manage clergy leadership formation programmes and activities. The latter brought into the discourse the need for participants (formators) to select and employ methodologies, methods, approaches and resources relevant to the southern African context where ACSA is located even though the study also acknowledged the influence of other Anglican Church contexts on what happened at the local level. In order to decipher meaning out of investigated phenomena about clergy leadership formation in ACSA, the study employed the critical realist “underlabouring” philosophy advanced by theorists such as Bhaskar to surface underlying mechanisms that exist at the level of the “real” in order to understand the causes of particular events and experiences as they manifest in the “actual” and “empirical” domains of the world, ACSA in the case of the study. In particular, the study engaged critically the opinion deliberated by critical realists concerning the interplay between structure and agency in relation to the responsibilities of the research participants (formators) in ACSA clergy leadership formation programmes and activities. For instance, the study had an interest in investigating why bishops (principal formators in ACSA) exercised their episcopal authority in the manner they do and why individual formators were concerned about particular issues which relate to the facilitation of clergy leadership formation in ACSA (agential reflexivity/subjectivity). The study observed that, in the case of diocesan bishops, critical realists would argue that, by virtue of the authority which comes with their responsibilities (agency), they have the power to influence transformation of practices in clergy leadership formation in ACSA at any given point in time. The flip side of the discourse was also taken note of: that some bishops, for reasons known to themselves and their predecessors, are often reluctant to embrace new ideas relating to clergy leadership formation practices in their dioceses. Further, through critical realist lens, the study concluded that Canons, Vision and Mission statements, Acts, and structures such as Synod of Bishops, Provincial Synod, ABoTE, Cott, and TfM structurally shape ACSA, thus providing the organisation with a stable ontology which ought to direct, regulate and control the manner in which clergy leadership formation programmes and activities were conceptualised, designed, planned, facilitated and managed. As such, the study had an interest in establishing what would happen, in relation to clergy leadership formation practices in ACSA, when these structures would have been activated? Beyond that, in view of the goal of the study, it was enquired how expansive learning processes could be helpful in responding to the research findings towards exploring collaborative and transforming clergy leadership formation practices in ACSA. Drawing from the conceptual framework which was carved in the study on the basis of the theoretical tools (critical realism and educational leadership theory) and methodological tools (CHAT orientated concepts) undergirded by the Vygotskian theorisation of human consciousness development, the study concluded that clergy leadership formation is a collaborative activity which calls for the recognition, appreciation and utilisation of available expertise in ACSA and provision of a platform where participants (formators) could engage collectively on issues relating to their work with the objective of building each other up in knowledge and skills (expansive learning) towards realisation of the goals and objectives of the organisation. Diverse understandings (contradictions) of what needed to be prioritised in the facilitation of clergy leadership formation in ACSA would be considered as a positive rather than a negative. Ultimately, through the use of inductive, abductive and retroductive modes of inference, the study modelled a transforming, transformational, transformative, embodied and incarnational model of clergy leadership formation which ACSA could consider using in future deliberations on the object of study particularly in relation to the key research findings across the case studies which were used in the study.
- Full Text:
Stakeholder relationship management of a Chinese Mining Organisation in Zimbabwe
- Authors: Chodokufa, Kudakwashe
- Date: 2019
- Subjects: Industrial management -- Zimbabwe , Mineral industries -- Zimbabwe -- Management , Investments, Chinese -- Zimbabwe
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/115127 , vital:34080
- Description: Media reports and research has pointed out problems in the way that Chinese mining organisations in Zimbabwe are managing stakeholder relationships. The problems ranging from disgruntled communities and allegations of labour violations. Taking into account the impact that China’s FDI has had on the ailing Zimbabwean economy research into the management of stakeholder relationships becomes imperative to understand how Chinese mining organisations build and manage stakeholder relationships. A review of stakeholder theory has revealed that there is not much emphasis by researchers on how organisations manage their stakeholder relationships, but rather on the identification and analysis of stakeholders. Research that has focused on stakeholder relationships has focused on different elements found in stakeholder relationship management and not necessarily on how stakeholder relationships should be managed. On the other hand, stakeholder theory does not seem to include social licence to operate which is important in stakeholder relationship management within the mining context. The purpose of this study is to develop a multidimensional stakeholder relationship management process for the Chinese mining organisation in Zimbabwe, showing dynamic interactions between multiple stakeholder networks with complementary, competitive and/or cooperative interests, while taking into account the possibility that interests may vary according to the underlying context. Thirteen semi-structured in-depth interviews were conducted with three stakeholder groups of a Chinese mining organisation as identified from the literature, namely employees, government and the community. The critical incident technique (CIT) was adopted in developing the interview questions and facilitated the data collection process. Participants described 36 critical incidents. According to multiple stakeholders, the findings suggest that, the Chinese managers built the relationship with multiple stakeholders through friendship, negotiation, pretend not to understand, referral, singing a contract, started with problems, they just arrived and through the government. With the same relationship being managed by the Chinese managers by being hard, rough and ruthless, authoritative, Chinese way of doing things, used avoidance, lack of competency, through a third party and resolving conflict when managing stakeholder relationships. Showing that the building and managing of stakeholder relationships is socially constructed and experienced differently by stakeholders. The positive and negative relationship characteristics influenced how stakeholder relationships are managed by the selected Chinese mining organisation. In the presence of positive relationship characteristics which included, friendship,there was flexibility, power dynamics, accountability depends on situations, commitment a show of investment, do cooperate to a certain extent, trust began with an open mind, shared values: hardwork and profit, shared values: culture was associated with the Chinese managing the relationship through being kind, supportive, motivating and understanding; complaint; through a third party; controlling; Chinese way of doing things; and performance and reward management of stakeholder relationships. Whilst negative relationship characteristics which included fear, their hearts were hardened, Chinese had power, intimidaton, not accountable, lack of commitment, communication understanding, connotations and intretations, communication done through a third party; no cooperation want to cut coners; trust are they conveying what is being said; deception and misrepresentation; trust depends on experience; being told lies and not transparent were associated with negative (being authoritative; hard, rough and ruthless; avoidance; blame shifting and pushy) stakeholder relationship management by the Chinese managers. Hence, a proposition that negative or positive relationship characteristics result in negative or positive stakeholder relationship management by the Chinese managers was propossed. The following challenges were experienced in the management of stakeholder relationships namely, communication, corruption, cheating, political environment, working conditions and broken promises. The dynamic multidimensional stakeholder relationship management process was subsequently revised to accommodate the new relationship characteristics and their positive and negative influence on how stakeholder relationships are managed. The main contribution of this study is the dynamic multidimensional stakeholder relationship management process which was developed within the context of a Chinese mining organisation in Africa. It is recommended that practitioners utilise the dynamic multidimensional stakeholder relationship management process to assist them in understanding and conducting research on stakeholder relationships. Further research is suggested on developing the research proposition made in the study and to empirically test the dynamic multidimension stakeholder relationship management process in other industries that posses different or similar contexts as this study.
- Full Text:
- Authors: Chodokufa, Kudakwashe
- Date: 2019
- Subjects: Industrial management -- Zimbabwe , Mineral industries -- Zimbabwe -- Management , Investments, Chinese -- Zimbabwe
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/115127 , vital:34080
- Description: Media reports and research has pointed out problems in the way that Chinese mining organisations in Zimbabwe are managing stakeholder relationships. The problems ranging from disgruntled communities and allegations of labour violations. Taking into account the impact that China’s FDI has had on the ailing Zimbabwean economy research into the management of stakeholder relationships becomes imperative to understand how Chinese mining organisations build and manage stakeholder relationships. A review of stakeholder theory has revealed that there is not much emphasis by researchers on how organisations manage their stakeholder relationships, but rather on the identification and analysis of stakeholders. Research that has focused on stakeholder relationships has focused on different elements found in stakeholder relationship management and not necessarily on how stakeholder relationships should be managed. On the other hand, stakeholder theory does not seem to include social licence to operate which is important in stakeholder relationship management within the mining context. The purpose of this study is to develop a multidimensional stakeholder relationship management process for the Chinese mining organisation in Zimbabwe, showing dynamic interactions between multiple stakeholder networks with complementary, competitive and/or cooperative interests, while taking into account the possibility that interests may vary according to the underlying context. Thirteen semi-structured in-depth interviews were conducted with three stakeholder groups of a Chinese mining organisation as identified from the literature, namely employees, government and the community. The critical incident technique (CIT) was adopted in developing the interview questions and facilitated the data collection process. Participants described 36 critical incidents. According to multiple stakeholders, the findings suggest that, the Chinese managers built the relationship with multiple stakeholders through friendship, negotiation, pretend not to understand, referral, singing a contract, started with problems, they just arrived and through the government. With the same relationship being managed by the Chinese managers by being hard, rough and ruthless, authoritative, Chinese way of doing things, used avoidance, lack of competency, through a third party and resolving conflict when managing stakeholder relationships. Showing that the building and managing of stakeholder relationships is socially constructed and experienced differently by stakeholders. The positive and negative relationship characteristics influenced how stakeholder relationships are managed by the selected Chinese mining organisation. In the presence of positive relationship characteristics which included, friendship,there was flexibility, power dynamics, accountability depends on situations, commitment a show of investment, do cooperate to a certain extent, trust began with an open mind, shared values: hardwork and profit, shared values: culture was associated with the Chinese managing the relationship through being kind, supportive, motivating and understanding; complaint; through a third party; controlling; Chinese way of doing things; and performance and reward management of stakeholder relationships. Whilst negative relationship characteristics which included fear, their hearts were hardened, Chinese had power, intimidaton, not accountable, lack of commitment, communication understanding, connotations and intretations, communication done through a third party; no cooperation want to cut coners; trust are they conveying what is being said; deception and misrepresentation; trust depends on experience; being told lies and not transparent were associated with negative (being authoritative; hard, rough and ruthless; avoidance; blame shifting and pushy) stakeholder relationship management by the Chinese managers. Hence, a proposition that negative or positive relationship characteristics result in negative or positive stakeholder relationship management by the Chinese managers was propossed. The following challenges were experienced in the management of stakeholder relationships namely, communication, corruption, cheating, political environment, working conditions and broken promises. The dynamic multidimensional stakeholder relationship management process was subsequently revised to accommodate the new relationship characteristics and their positive and negative influence on how stakeholder relationships are managed. The main contribution of this study is the dynamic multidimensional stakeholder relationship management process which was developed within the context of a Chinese mining organisation in Africa. It is recommended that practitioners utilise the dynamic multidimensional stakeholder relationship management process to assist them in understanding and conducting research on stakeholder relationships. Further research is suggested on developing the research proposition made in the study and to empirically test the dynamic multidimension stakeholder relationship management process in other industries that posses different or similar contexts as this study.
- Full Text:
Pyramidal deliberative democracy
- Authors: Danielsen, James
- Date: 2019
- Subjects: Democracy , Information technology -- Political aspects , Internet in public administration , Political participation -- Computer network resources , World politics
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/74502 , vital:30309
- Description: This dissertation has two main objectives. First, to outline an ICT-facilitated model of democracy called ‘pyramidal democracy’ that reconciles deliberative democracy with mass engagement. Second, to suggest how this model of democracy might engender the democratisation of the global economy and thus the provision of a basic level of economic security for all global citizens. At the core of the model is the pyramidal deliberative network, a means of organising citizens into small online deliberative groups and linking these groups together by means of an iterative process of delegate-selection and group-formation. The pyramidal network enables citizens to aggregate their preferences in a deliberative manner, and then project social power by authorizing the delegates at the top-tier of the pyramidal network to communicate their social demands to elected officials or to other points of authority. The envisioned outcome is the democratisation of the public sphere by means of the proliferation of deliberative networks in the government, market, and civil society spheres. Transnational pyramidal networks may make it feasible to instantiate a new citizen-based schema of global governance and, thereby, facilitate the reform of the United Nations and enable a transition towards global peace, sustainability, and distributive justice. Distributive justice might be achieved by means of implementing the six components of a democratised economy: participatory budgeting, fee-and-dividend taxes, a basic income, monetary reform, workplace democracy, and the sharing economy. Taken together, these components might enable the universal provision of a social minimum – a universal basic income sufficient for basic security and real freedom. Taken to its logical conclusion, a democratised economy may also enable a transition towards a post-scarcity economic order characterised by a maximal stock of humanmade and natural capital that would not exceed the sustainable carrying capacity of the earth.
- Full Text:
- Authors: Danielsen, James
- Date: 2019
- Subjects: Democracy , Information technology -- Political aspects , Internet in public administration , Political participation -- Computer network resources , World politics
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/74502 , vital:30309
- Description: This dissertation has two main objectives. First, to outline an ICT-facilitated model of democracy called ‘pyramidal democracy’ that reconciles deliberative democracy with mass engagement. Second, to suggest how this model of democracy might engender the democratisation of the global economy and thus the provision of a basic level of economic security for all global citizens. At the core of the model is the pyramidal deliberative network, a means of organising citizens into small online deliberative groups and linking these groups together by means of an iterative process of delegate-selection and group-formation. The pyramidal network enables citizens to aggregate their preferences in a deliberative manner, and then project social power by authorizing the delegates at the top-tier of the pyramidal network to communicate their social demands to elected officials or to other points of authority. The envisioned outcome is the democratisation of the public sphere by means of the proliferation of deliberative networks in the government, market, and civil society spheres. Transnational pyramidal networks may make it feasible to instantiate a new citizen-based schema of global governance and, thereby, facilitate the reform of the United Nations and enable a transition towards global peace, sustainability, and distributive justice. Distributive justice might be achieved by means of implementing the six components of a democratised economy: participatory budgeting, fee-and-dividend taxes, a basic income, monetary reform, workplace democracy, and the sharing economy. Taken together, these components might enable the universal provision of a social minimum – a universal basic income sufficient for basic security and real freedom. Taken to its logical conclusion, a democratised economy may also enable a transition towards a post-scarcity economic order characterised by a maximal stock of humanmade and natural capital that would not exceed the sustainable carrying capacity of the earth.
- Full Text:
From ‘cleanliness is next to Godliness’ to ‘without perfect health, there is nothing’: discourses of healthy lifestyle in the construction of young adult identities in urban South Africa
- Authors: De Jong, Michelle
- Date: 2019
- Subjects: Health , Cleanliness , Social structure -- Health aspects , Health behavior , Social medicine
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/64940 , vital:28638
- Description: This research explores popular constructions of “healthiness” as individual lifestyle choices in the context of contemporary South African consumer culture, and how these constructions relate to formations of subjectivity. This is a qualitative study conducted within a social constructionist, theoretical framework. Data was collected using in-depth, semi structured interviews and are analysed using a Foucauldian inspired version of discourse analysis. A critical stance is taken towards the assumption in these discourses that their version of healthiness is always and unquestionably positive. Special attention is paid to the lifestyle and marketing media discourses appropriated in understandings of personal health through self-management, and of the optimization of health in the pursuit of well-being. The ways in which different discourses of healthiness facilitate the construction of specific identities are considered in order to untangle some of the problems created by the moralism underpinning popular consumer health discourse. How constructions of healthiness and aspirant healthy lifestyles support, and are supported by, the ideologies and practices of neoliberal capitalism are also explored. From this perspective, healthiness as lifestyle consumption choices can be seen as an ideological apparatus that produces the subjects necessary to reproduce the social order (Althusser, 2001), functioning not only positively amongst the social classes with the leisure and economic resources to pursue these options, but also negatively as victim-blaming of those who are excluded. The argument here is not that health is bad or that people should not be bothered with activities aimed at promoting good health, but that in a context where the concept of health is idealised as always positive and beneficial, the potentially harmful consequences of some of the health discourses we make use of may be occluded. This idealisation of health or ‘healthism’ may also function to divert attention away from some of the challenges to health that are not the direct result of personal behaviours and are unlikely to be remedied through individually focussed interventions, for example, inequality and inadequate access to basic resources. Six discourses which were used to construct understandings of health are analysed. These include Happiness, Freedom, Control, Care, Balance and Goodness. The ways in which these discourses played a role in constructing the kinds of subject positions which were made available to participants, and the possible implications this has, are explored in depth.
- Full Text:
- Authors: De Jong, Michelle
- Date: 2019
- Subjects: Health , Cleanliness , Social structure -- Health aspects , Health behavior , Social medicine
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/64940 , vital:28638
- Description: This research explores popular constructions of “healthiness” as individual lifestyle choices in the context of contemporary South African consumer culture, and how these constructions relate to formations of subjectivity. This is a qualitative study conducted within a social constructionist, theoretical framework. Data was collected using in-depth, semi structured interviews and are analysed using a Foucauldian inspired version of discourse analysis. A critical stance is taken towards the assumption in these discourses that their version of healthiness is always and unquestionably positive. Special attention is paid to the lifestyle and marketing media discourses appropriated in understandings of personal health through self-management, and of the optimization of health in the pursuit of well-being. The ways in which different discourses of healthiness facilitate the construction of specific identities are considered in order to untangle some of the problems created by the moralism underpinning popular consumer health discourse. How constructions of healthiness and aspirant healthy lifestyles support, and are supported by, the ideologies and practices of neoliberal capitalism are also explored. From this perspective, healthiness as lifestyle consumption choices can be seen as an ideological apparatus that produces the subjects necessary to reproduce the social order (Althusser, 2001), functioning not only positively amongst the social classes with the leisure and economic resources to pursue these options, but also negatively as victim-blaming of those who are excluded. The argument here is not that health is bad or that people should not be bothered with activities aimed at promoting good health, but that in a context where the concept of health is idealised as always positive and beneficial, the potentially harmful consequences of some of the health discourses we make use of may be occluded. This idealisation of health or ‘healthism’ may also function to divert attention away from some of the challenges to health that are not the direct result of personal behaviours and are unlikely to be remedied through individually focussed interventions, for example, inequality and inadequate access to basic resources. Six discourses which were used to construct understandings of health are analysed. These include Happiness, Freedom, Control, Care, Balance and Goodness. The ways in which these discourses played a role in constructing the kinds of subject positions which were made available to participants, and the possible implications this has, are explored in depth.
- Full Text:
An investigation into the performance of smallholder irrigation schemes in Limpopo Province, South Africa: success factors, typologies and implications for development
- Denison, Jonathan Anthony Noel
- Authors: Denison, Jonathan Anthony Noel
- Date: 2019
- Subjects: Irrigation projects -- South Africa -- Limpopo , Farms, Small -- South Africa -- Limpopo , Land use -- South Africa -- Limpopo , Water-supply -- South Africa -- Limpopo
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/92317 , vital:30709
- Description: The research aimed to determine the factors that contribute to the success or failure of smallholder irrigation schemes in the Limpopo Province. It focussed on public-schemes where farmers share the water system Limpopo Province has more than half of the smallholder irrigation schemes in the country with an equipped area of approximately 28 000 ha. The main aims of the research were to identify key factors that explain performance and to develop a contemporary irrigation scheme typology. The research intended to provide a better perspective on how to focus investments across the multiple thematic areas that are associated with sustained and profitable irrigation farming activity. A survey of 102 irrigation schemes was conducted, comprising 82% of the population of schemes greater than 20 ha in Limpopo Province. The quantitative survey complemented prior in-depth qualitative research undertaken on Limpopo schemes. Data was consolidated into five performance indicators and 13 characteristic factors that impact performance. Schemes were viewed as technical and socio-biological systems where performance was determined by the dynamic interaction of multiple factors. The analysis was done in a complex systems framework using correlation, cluster and principle component analysis. It was postulated that over-arching concepts of productivity, profitability and manageability would explain why schemes succeed or fail. The schemes were found to be relatively very small in size with three quarters (74.8%) of them falling in the 50 to 250 ha size range, and only 11 schemes larger than 250 ha. Average plot sizes were 1.34 ha with a wide range between 0.18 and 16.25 ha. There were 65 operational schemes (equivalent to 63.7%), and 37 had failed (equivalent to 36.3%). Using a criterion for success of greater than 50% cropping intensity (to align with other studies and below which schemes can be considered to have failed), the success rate of the Limpopo schemes was 58%. The result was similar to the rest of South Africa and the same as the average rate for SADC identified in other studies using the same criterion. The schemes exhibited a mixed production purpose on average, with a significant market emphasis indicating these schemes have largely evolved from ‘food schemes’ to partly market-farming. Main crops grown were summer-maize and winter fresh-vegetables and cropping intensities on operational schemes ranged widely from 10% to 175%, with an average of 94%. Failure was associated with three dominant factors: energy type; infrastructure condition; and water resource constraints. The first two factors showed that manageability of technology was important. There is strong empirical evidence that pumped smallholder schemes are vulnerable in their physical form, prone to functional and financial failure, live much shorter lives, and perform no better than gravity-canal schemes. Out of the 37 schemes that failed, 34 (91.8%) were pumped. Pumped schemes tend to collapse suddenly while young and exhibit lower cut-off thresholds in productivity that, when crossed, trigger collapse. They also have much lower resilience to factors such as water stress or low farm-profitability. Pumped schemes need higher levels farm sophistication, market-oriented farming, and operational capability to keep the pumping pressure up. Water resource constraints were widespread, considerably more so on gravity schemes. Commercialising farmers were inhibited by lack of access to knowledge. Success was associated with numerous factors, but two findings stand out; the performance of gravity systems and the prevalence of land-exchange activity; the latter enabled by institutional flexibility and reflecting a process of ‘bricolage’ at play. Increased plot size was associated with increased commercialisation and, when larger than 1.8 ha, only commercialised farming was pursued. Market proximity seemed to play a role in increased longevity and to market access in commercialisation. These findings highlighted the importance of productivity and profitability in explaining success. Gravity schemes performed much more strongly in terms of longevity (nearly four times longer-lived) and similarly to pumped schemes in terms of cropping intensity. This was achieved under much greater water stress and with considerably worse infrastructure condition. Water efficiency was determined to be high on half of the schemes that were using short-furrow irrigation; equivalent, in a basin perspective, to drip irrigation. Two of the three top performing schemes (>150% intensity) were old gravity schemes. Farmers on approximately 75% of Limpopo smallholder schemes are currently engaging in land exchange transactions in a highly insecure and un-formalised institutional setup. Land exchange prevalence longer than two years was moderately associated with cropping intensity and strongly associated with commercialisation. This result has three important implications. First, it suggests that more land is utilised on the schemes when there is vibrant land-leasing activity. Secondly, schemes with a higher prevalence of long-term leasing seem to have a strong tendency to be more commercialised. Thirdly, the duration of the lease is significant, as neither single-season, nor annual leases yielded any positive associations, while those exchanges that were two years or longer, were associated with increased performance. These findings highlight the potential for longer-term land-exchange interventions to address the widespread low land utilisation on smallholder schemes, and to catalyse more commercially-oriented farming. An irrigation scheme typology was derived from the cluster analysis and was aligned to a contemporary irrigation farming typology. The key descriptors included technology type, purpose of farming and scheme management type. By matching scheme type to the farmer typology (or typologies), strategic decisions regarding technology choices for infrastructure, land, and water institutional interventions can be better informed. All schemes demand attention to the multiple factors required to achieve performance, not least water-tenure security, irrigation management organisational development, and infrastructure modernisation. Complexity was demonstrated by the finding that multiple factors contribute to success, and that there are many dimensions that change independently and have a cascading effect through the system in ways that are difficult to predict. Agricultural systems support to achieve productivity and profitability are essential for success. The research findings lead to the recommendation that, in addition, strategic planners must also consider the implications of the dominant factors of water-technology choices so that these are manageable, and the dynamics of farm-size change based on land exchange processes, in order to harness new opportunities to maximise irrigation scheme performance in future.
- Full Text:
- Authors: Denison, Jonathan Anthony Noel
- Date: 2019
- Subjects: Irrigation projects -- South Africa -- Limpopo , Farms, Small -- South Africa -- Limpopo , Land use -- South Africa -- Limpopo , Water-supply -- South Africa -- Limpopo
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/92317 , vital:30709
- Description: The research aimed to determine the factors that contribute to the success or failure of smallholder irrigation schemes in the Limpopo Province. It focussed on public-schemes where farmers share the water system Limpopo Province has more than half of the smallholder irrigation schemes in the country with an equipped area of approximately 28 000 ha. The main aims of the research were to identify key factors that explain performance and to develop a contemporary irrigation scheme typology. The research intended to provide a better perspective on how to focus investments across the multiple thematic areas that are associated with sustained and profitable irrigation farming activity. A survey of 102 irrigation schemes was conducted, comprising 82% of the population of schemes greater than 20 ha in Limpopo Province. The quantitative survey complemented prior in-depth qualitative research undertaken on Limpopo schemes. Data was consolidated into five performance indicators and 13 characteristic factors that impact performance. Schemes were viewed as technical and socio-biological systems where performance was determined by the dynamic interaction of multiple factors. The analysis was done in a complex systems framework using correlation, cluster and principle component analysis. It was postulated that over-arching concepts of productivity, profitability and manageability would explain why schemes succeed or fail. The schemes were found to be relatively very small in size with three quarters (74.8%) of them falling in the 50 to 250 ha size range, and only 11 schemes larger than 250 ha. Average plot sizes were 1.34 ha with a wide range between 0.18 and 16.25 ha. There were 65 operational schemes (equivalent to 63.7%), and 37 had failed (equivalent to 36.3%). Using a criterion for success of greater than 50% cropping intensity (to align with other studies and below which schemes can be considered to have failed), the success rate of the Limpopo schemes was 58%. The result was similar to the rest of South Africa and the same as the average rate for SADC identified in other studies using the same criterion. The schemes exhibited a mixed production purpose on average, with a significant market emphasis indicating these schemes have largely evolved from ‘food schemes’ to partly market-farming. Main crops grown were summer-maize and winter fresh-vegetables and cropping intensities on operational schemes ranged widely from 10% to 175%, with an average of 94%. Failure was associated with three dominant factors: energy type; infrastructure condition; and water resource constraints. The first two factors showed that manageability of technology was important. There is strong empirical evidence that pumped smallholder schemes are vulnerable in their physical form, prone to functional and financial failure, live much shorter lives, and perform no better than gravity-canal schemes. Out of the 37 schemes that failed, 34 (91.8%) were pumped. Pumped schemes tend to collapse suddenly while young and exhibit lower cut-off thresholds in productivity that, when crossed, trigger collapse. They also have much lower resilience to factors such as water stress or low farm-profitability. Pumped schemes need higher levels farm sophistication, market-oriented farming, and operational capability to keep the pumping pressure up. Water resource constraints were widespread, considerably more so on gravity schemes. Commercialising farmers were inhibited by lack of access to knowledge. Success was associated with numerous factors, but two findings stand out; the performance of gravity systems and the prevalence of land-exchange activity; the latter enabled by institutional flexibility and reflecting a process of ‘bricolage’ at play. Increased plot size was associated with increased commercialisation and, when larger than 1.8 ha, only commercialised farming was pursued. Market proximity seemed to play a role in increased longevity and to market access in commercialisation. These findings highlighted the importance of productivity and profitability in explaining success. Gravity schemes performed much more strongly in terms of longevity (nearly four times longer-lived) and similarly to pumped schemes in terms of cropping intensity. This was achieved under much greater water stress and with considerably worse infrastructure condition. Water efficiency was determined to be high on half of the schemes that were using short-furrow irrigation; equivalent, in a basin perspective, to drip irrigation. Two of the three top performing schemes (>150% intensity) were old gravity schemes. Farmers on approximately 75% of Limpopo smallholder schemes are currently engaging in land exchange transactions in a highly insecure and un-formalised institutional setup. Land exchange prevalence longer than two years was moderately associated with cropping intensity and strongly associated with commercialisation. This result has three important implications. First, it suggests that more land is utilised on the schemes when there is vibrant land-leasing activity. Secondly, schemes with a higher prevalence of long-term leasing seem to have a strong tendency to be more commercialised. Thirdly, the duration of the lease is significant, as neither single-season, nor annual leases yielded any positive associations, while those exchanges that were two years or longer, were associated with increased performance. These findings highlight the potential for longer-term land-exchange interventions to address the widespread low land utilisation on smallholder schemes, and to catalyse more commercially-oriented farming. An irrigation scheme typology was derived from the cluster analysis and was aligned to a contemporary irrigation farming typology. The key descriptors included technology type, purpose of farming and scheme management type. By matching scheme type to the farmer typology (or typologies), strategic decisions regarding technology choices for infrastructure, land, and water institutional interventions can be better informed. All schemes demand attention to the multiple factors required to achieve performance, not least water-tenure security, irrigation management organisational development, and infrastructure modernisation. Complexity was demonstrated by the finding that multiple factors contribute to success, and that there are many dimensions that change independently and have a cascading effect through the system in ways that are difficult to predict. Agricultural systems support to achieve productivity and profitability are essential for success. The research findings lead to the recommendation that, in addition, strategic planners must also consider the implications of the dominant factors of water-technology choices so that these are manageable, and the dynamics of farm-size change based on land exchange processes, in order to harness new opportunities to maximise irrigation scheme performance in future.
- Full Text:
A development method for deriving reusable concurrent programs from verified CSP models
- Authors: Dibley, James
- Date: 2019
- Subjects: CSP (Computer program language) , Sequential processing (Computer science) , Go (Computer program language) , CSPIDER (Open source tool)
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/72329 , vital:30035
- Description: This work proposes and demonstrates a novel method for software development that applies formal verification techniques to the design and implementation of concurrent programs. This method is supported by a new software tool, CSPIDER, which translates machine-readable Communicating Sequential Processes (CSP) models into encapsulated, reusable components coded in the Go programming language. In relation to existing CSP implementation techniques, this work is only the second to implement a translator and it provides original support for some CSP language constructs and modelling approaches. The method is evaluated through three case studies: a concurrent sorting array, a trialdivision prime number generator, and a component node for the Ricart-Agrawala distributed mutual exclusion algorithm. Each of these case studies presents the formal verification of safety and functional requirements through CSP model-checking, and it is shown that CSPIDER is capable of generating reusable implementations from each model. The Ricart-Agrawala case study demonstrates the application of the method to the design of a protocol component. This method maintains full compatibility with the primary CSP verification tool. Applying the CSPIDER tool requires minimal commitment to an explicitly defined modelling style and a very small set of pre-translation annotations, but all of these measures can be instated prior to verification. The Go code that CSPIDER produces requires no intervention before it may be used as a component within a larger development. The translator provides a traceable, structured implementation of the CSP model, automatically deriving formal parameters and a channel-based client interface from its interpretation of the CSP model. Each case study demonstrates the use of the translated component within a simple test development.
- Full Text:
- Authors: Dibley, James
- Date: 2019
- Subjects: CSP (Computer program language) , Sequential processing (Computer science) , Go (Computer program language) , CSPIDER (Open source tool)
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/72329 , vital:30035
- Description: This work proposes and demonstrates a novel method for software development that applies formal verification techniques to the design and implementation of concurrent programs. This method is supported by a new software tool, CSPIDER, which translates machine-readable Communicating Sequential Processes (CSP) models into encapsulated, reusable components coded in the Go programming language. In relation to existing CSP implementation techniques, this work is only the second to implement a translator and it provides original support for some CSP language constructs and modelling approaches. The method is evaluated through three case studies: a concurrent sorting array, a trialdivision prime number generator, and a component node for the Ricart-Agrawala distributed mutual exclusion algorithm. Each of these case studies presents the formal verification of safety and functional requirements through CSP model-checking, and it is shown that CSPIDER is capable of generating reusable implementations from each model. The Ricart-Agrawala case study demonstrates the application of the method to the design of a protocol component. This method maintains full compatibility with the primary CSP verification tool. Applying the CSPIDER tool requires minimal commitment to an explicitly defined modelling style and a very small set of pre-translation annotations, but all of these measures can be instated prior to verification. The Go code that CSPIDER produces requires no intervention before it may be used as a component within a larger development. The translator provides a traceable, structured implementation of the CSP model, automatically deriving formal parameters and a channel-based client interface from its interpretation of the CSP model. Each case study demonstrates the use of the translated component within a simple test development.
- Full Text:
Examining mathematical reasoning through enacted visualisation
- Authors: Dongwi, Beata Lididimikeni
- Date: 2019
- Subjects: Visualization , Mathematics -- Study and teaching -- Namibia , Mathematics -- Study and teaching -- Audio-visual aids , Geometry -- Study and teaching , Reasoning , Mathematical ability
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/68192 , vital:29217
- Description: This study sets out to analyse the co-emergence of visualisation and reasoning processes when selected learners engaged in solving word problems. The study argues that visualisation processes and mathematical reasoning processes are closely interlinked in the process of engaging in any mathematical activity. This qualitative research project adopted a case study methodology embedded within a broader interpretative orientation. The research participants were a cohort of 17 mixedgender and mixed-ability Grade 11 learners from a private school in southern Namibia. Data was collected in three phases and comprised of one-on-one task-based interviews in the first phase, focus group task-based interviews in the second, and semi-structured reflective interviews in the third. The analytical framework was informed by elements of enactivism and consisted of a hybrid of observable visualisation and mathematical reasoning indicators. The study was framed by an enactivist perspective that served as a linking mediator to bring visualisation and reasoning processes together, and as a lens through which the coemergence of these processes was observed and analysed. The key enactivist concepts of structural coupling and co-emergence were the two mediating ideas that enabled me to discuss the links between visualisation and reasoning that emerged whilst my participants solved the set word problems. The study argues that the visualisation processes enacted by the participants when solving these problems are inseparable from the reasoning processes that the participants brought to bear; that is, they co-emerged.
- Full Text:
- Authors: Dongwi, Beata Lididimikeni
- Date: 2019
- Subjects: Visualization , Mathematics -- Study and teaching -- Namibia , Mathematics -- Study and teaching -- Audio-visual aids , Geometry -- Study and teaching , Reasoning , Mathematical ability
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/68192 , vital:29217
- Description: This study sets out to analyse the co-emergence of visualisation and reasoning processes when selected learners engaged in solving word problems. The study argues that visualisation processes and mathematical reasoning processes are closely interlinked in the process of engaging in any mathematical activity. This qualitative research project adopted a case study methodology embedded within a broader interpretative orientation. The research participants were a cohort of 17 mixedgender and mixed-ability Grade 11 learners from a private school in southern Namibia. Data was collected in three phases and comprised of one-on-one task-based interviews in the first phase, focus group task-based interviews in the second, and semi-structured reflective interviews in the third. The analytical framework was informed by elements of enactivism and consisted of a hybrid of observable visualisation and mathematical reasoning indicators. The study was framed by an enactivist perspective that served as a linking mediator to bring visualisation and reasoning processes together, and as a lens through which the coemergence of these processes was observed and analysed. The key enactivist concepts of structural coupling and co-emergence were the two mediating ideas that enabled me to discuss the links between visualisation and reasoning that emerged whilst my participants solved the set word problems. The study argues that the visualisation processes enacted by the participants when solving these problems are inseparable from the reasoning processes that the participants brought to bear; that is, they co-emerged.
- Full Text:
Governing pregnancy in South Africa: political and health debate, policy and procedures
- Authors: Du Plessis, Ulandi
- Date: 2019
- Subjects: South Africa. Department of Health (1994- ) , Maternal health services -- South Africa , Mothers -- Mortality -- South Africa , Prenatal care -- South Africa , African mothers -- Mortality -- South Africa
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/76552 , vital:30600
- Description: South Africa democratised in 1994. However, due to the discriminatory and segregationist character of the preceding regime, vast swathes of the country’s spaces and people entered the democratic period heavily deprived of essential government services. This was the case with health care in general, including maternal health care. There were also little to no national data available on maternal deaths, especially among the black population. One of the first tasks of the new National Department of Health (NDoH) was to target the high maternal mortality rate. The NDoH made maternal deaths notifiable by law and instituted auditing and information gathering systems in the health sector; health infrastructure was expanded exponentially, and maternal health care was made free. Despite this, the last 24 years have seen the maternal mortality escalate. The latest statistics show that between 1200 and 1300 women die in the South African public health sector each year during pregnancy and the puerperium. This puts the current institutional maternal mortality rate (MMR) at around 154/100 000 live births. The international target for ‘developing’ countries was to reduce the MMR rate by three quarters by 2015, which would have meant a reduction to 38/100 000 live births. The aim of this dissertation is to examine how the democratic South African government (influenced heavily by global health thinking) has laboured to reduce that statistic. I analyse, using Foucauldian discourse analysis, all relevant health and maternal health policies, procedural documents and reports produced by and for the NDoH in the last 24 years. I draw on Foucauldian concepts, specifically those related to Foucault’s work on governmentality. In this dissertation I introduce a new perspective towards the maternal health practices implemented in South Africa, practices that have generally remained unquestioned, been perceived as self-evident, and thus often escaping critical analysis. Through an analysis of the intended operation of the public antenatal clinic (within the larger institutional system) I show how ‘development’ has come to operate as a truth regime in South Africa – facilitating the introduction of liberal governmentality (including some advanced liberal practices) into public health service provision.
- Full Text:
- Authors: Du Plessis, Ulandi
- Date: 2019
- Subjects: South Africa. Department of Health (1994- ) , Maternal health services -- South Africa , Mothers -- Mortality -- South Africa , Prenatal care -- South Africa , African mothers -- Mortality -- South Africa
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/76552 , vital:30600
- Description: South Africa democratised in 1994. However, due to the discriminatory and segregationist character of the preceding regime, vast swathes of the country’s spaces and people entered the democratic period heavily deprived of essential government services. This was the case with health care in general, including maternal health care. There were also little to no national data available on maternal deaths, especially among the black population. One of the first tasks of the new National Department of Health (NDoH) was to target the high maternal mortality rate. The NDoH made maternal deaths notifiable by law and instituted auditing and information gathering systems in the health sector; health infrastructure was expanded exponentially, and maternal health care was made free. Despite this, the last 24 years have seen the maternal mortality escalate. The latest statistics show that between 1200 and 1300 women die in the South African public health sector each year during pregnancy and the puerperium. This puts the current institutional maternal mortality rate (MMR) at around 154/100 000 live births. The international target for ‘developing’ countries was to reduce the MMR rate by three quarters by 2015, which would have meant a reduction to 38/100 000 live births. The aim of this dissertation is to examine how the democratic South African government (influenced heavily by global health thinking) has laboured to reduce that statistic. I analyse, using Foucauldian discourse analysis, all relevant health and maternal health policies, procedural documents and reports produced by and for the NDoH in the last 24 years. I draw on Foucauldian concepts, specifically those related to Foucault’s work on governmentality. In this dissertation I introduce a new perspective towards the maternal health practices implemented in South Africa, practices that have generally remained unquestioned, been perceived as self-evident, and thus often escaping critical analysis. Through an analysis of the intended operation of the public antenatal clinic (within the larger institutional system) I show how ‘development’ has come to operate as a truth regime in South Africa – facilitating the introduction of liberal governmentality (including some advanced liberal practices) into public health service provision.
- Full Text:
Intersectionality and complexity in the representation of ‘queer’ sexualities and genders in African women’s short fiction
- Authors: Du Preez, Jenny Boźena
- Date: 2019
- Subjects: Sexual minority culture , Sexual minorities' writings , African fiction -- Women authors -- History and criticism , Gender identity in literature , Short stories, South African , Feminism in literature , Political poetry , Eroticism in literature , Lesbianism in literature
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/119047 , vital:34697
- Description: This thesis sets out to contribute to the growing body of knowledge about queer sexualities and genders in Africa by examining their depiction in selected post-2000 African women’s short fiction written in English. Post-2000, the short story form has become the primary vehicle for queer representations by African women writers, and is thus an important development in the burgeoning body of queer literature by African writers. Broadly speaking, this literary formation can be defined as anti-homophobic, feminist and politically pragmatic. Using an intersectional lens, this thesis sets out to examine four significant strands in the political work these stories engage in. The chapters are structured around four main points of contention that have particular significance at the intersection of ‘queer’, ‘women’ and ‘Africa’. Firstly, I examine South African short stories that perform what I call queer conversations with history: imaginatively asserting a queer South African history, writing back against a male-dominated and heterosexist literary canon and, in doing so, contributing to the reimagination of the contemporary South African nation. Secondly, I analyse short stories from Africa that foreground the family, both as social formation and ideology. I examine how these stories ‘fracture’ this powerful and naturalised heterosexist concept by depicting the tensions and contradictions that queer characters experience in relation to family. Thirdly, I consider short stories from various African contexts that work to reconceptualise queer sexuality in relation to religious discourse in order to challenge homophobic and patriarchal religious authority. Finally, I examine queer, feminist erotic short stories by African women writers that challenges various colonialist, racist, sexist and lesbophobic discourses that have historically stifled the portrayal of sex and erotic experience between women.
- Full Text:
- Authors: Du Preez, Jenny Boźena
- Date: 2019
- Subjects: Sexual minority culture , Sexual minorities' writings , African fiction -- Women authors -- History and criticism , Gender identity in literature , Short stories, South African , Feminism in literature , Political poetry , Eroticism in literature , Lesbianism in literature
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/119047 , vital:34697
- Description: This thesis sets out to contribute to the growing body of knowledge about queer sexualities and genders in Africa by examining their depiction in selected post-2000 African women’s short fiction written in English. Post-2000, the short story form has become the primary vehicle for queer representations by African women writers, and is thus an important development in the burgeoning body of queer literature by African writers. Broadly speaking, this literary formation can be defined as anti-homophobic, feminist and politically pragmatic. Using an intersectional lens, this thesis sets out to examine four significant strands in the political work these stories engage in. The chapters are structured around four main points of contention that have particular significance at the intersection of ‘queer’, ‘women’ and ‘Africa’. Firstly, I examine South African short stories that perform what I call queer conversations with history: imaginatively asserting a queer South African history, writing back against a male-dominated and heterosexist literary canon and, in doing so, contributing to the reimagination of the contemporary South African nation. Secondly, I analyse short stories from Africa that foreground the family, both as social formation and ideology. I examine how these stories ‘fracture’ this powerful and naturalised heterosexist concept by depicting the tensions and contradictions that queer characters experience in relation to family. Thirdly, I consider short stories from various African contexts that work to reconceptualise queer sexuality in relation to religious discourse in order to challenge homophobic and patriarchal religious authority. Finally, I examine queer, feminist erotic short stories by African women writers that challenges various colonialist, racist, sexist and lesbophobic discourses that have historically stifled the portrayal of sex and erotic experience between women.
- Full Text:
Physicochemical properties and photodynamic therapy activities of indium and zinc phthalocyanine-nanoparticle conjugates
- Authors: Dube, Edith
- Date: 2019
- Subjects: Indium , Zinc , Phthalocyanines , Breast -- Cancer -- Photochemotherapy , Nanoparticles
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/76506 , vital:30589
- Description: The syntheses and characterization of symmetric and asymmetric Pcs functionalized at the peripheral position are reported. The Pcs contain either zinc or indium as central metals and have carboxyphenoxy, phenoxy propanoic acid, benzothiazole phenoxy, thiophine ethoxy or di-O-isopropylidene-α-D-glucopyranose as ring substituents. The Pcs were linked to NPs via an amide bond or through self-assembly. The photophysics and photochemistry of the Pcs were assessed when alone and with conjugates. All the studied Pcs showed good photophysicochemical behaviour with relatively high triplet and singlet oxygen quantum yields corresponding to their low fluorescence quantum yield. The Pcs with indium in their central cavity exhibited higher triplet and singlet oxygen quantum yields in comparison to their zinc counterparts due to the heavy–atom effect obtained from the former. Asymmetrical Pcs displayed higher triplet and singlet oxygen quantum yields than their symmetrical counterparts. The triplet quantum yield, generally increased on linkage to nanoparticles (NPs) due to the heavy–atom effect of gold and silver in NPs. The conjugates to gold nanospheres yielded higher triplet and singlet quantum yields than their gold nanotriangles counterparts due to the higher loading by the former probably encouraged by their relatively small particle size. The in vitro dark cytotoxicity and photodynamic therapy of selected Pc complexes and conjugates against MCF-7 cells was tested. All studied Pc complexes and conjugates showed minimum dark toxicity making them applicable for PDT. All complexes displayed poor phototoxicity with >50Îll viability at concentrations≤ 160μg/mL, however the conjugates showed<50% cell viabilityatconcentrations≤ 160μg/mLprobably due to the enhanced singlet oxygen quantum yield. The findings from this work show the importance of linking photosensitises such as phthalocyanines to metal nanoparticles for the enhancement ofsinglet oxygen quantum yield and ultimately the photodynamic effect.
- Full Text:
- Authors: Dube, Edith
- Date: 2019
- Subjects: Indium , Zinc , Phthalocyanines , Breast -- Cancer -- Photochemotherapy , Nanoparticles
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/76506 , vital:30589
- Description: The syntheses and characterization of symmetric and asymmetric Pcs functionalized at the peripheral position are reported. The Pcs contain either zinc or indium as central metals and have carboxyphenoxy, phenoxy propanoic acid, benzothiazole phenoxy, thiophine ethoxy or di-O-isopropylidene-α-D-glucopyranose as ring substituents. The Pcs were linked to NPs via an amide bond or through self-assembly. The photophysics and photochemistry of the Pcs were assessed when alone and with conjugates. All the studied Pcs showed good photophysicochemical behaviour with relatively high triplet and singlet oxygen quantum yields corresponding to their low fluorescence quantum yield. The Pcs with indium in their central cavity exhibited higher triplet and singlet oxygen quantum yields in comparison to their zinc counterparts due to the heavy–atom effect obtained from the former. Asymmetrical Pcs displayed higher triplet and singlet oxygen quantum yields than their symmetrical counterparts. The triplet quantum yield, generally increased on linkage to nanoparticles (NPs) due to the heavy–atom effect of gold and silver in NPs. The conjugates to gold nanospheres yielded higher triplet and singlet quantum yields than their gold nanotriangles counterparts due to the higher loading by the former probably encouraged by their relatively small particle size. The in vitro dark cytotoxicity and photodynamic therapy of selected Pc complexes and conjugates against MCF-7 cells was tested. All studied Pc complexes and conjugates showed minimum dark toxicity making them applicable for PDT. All complexes displayed poor phototoxicity with >50Îll viability at concentrations≤ 160μg/mL, however the conjugates showed<50% cell viabilityatconcentrations≤ 160μg/mLprobably due to the enhanced singlet oxygen quantum yield. The findings from this work show the importance of linking photosensitises such as phthalocyanines to metal nanoparticles for the enhancement ofsinglet oxygen quantum yield and ultimately the photodynamic effect.
- Full Text:
A physiological study on a commercial reef fish to quantify the relationship between exploitation and climate change resilience
- Authors: Duncan, Murray Ian
- Date: 2019
- Subjects: Chrysoblephus laticeps -- Climatic factors , Chrysoblephus laticeps -- Physiology , Sparidae -- South Africa -- Climatic factors , Reef fishes -- South Africa -- Climatic factors , Fish populations -- South Africa -- Climatic factors , Fish populations -- Measurement , Fish populations -- Monitoring , Fisheries -- South Africa -- Environmental aspects , Ocean temperature -- Physiological effect -- South Africa
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/76541 , vital:30599
- Description: The persistence of harvested fish populations in the Anthropocene will be determined, above all, by how they respond to the interacting effects of climate change and fisheries exploitation. Predicting how populations will respond to both these threats is essential for any adaptive and sustainable management strategy. The response of fish populations to climate change is underpinned by physiological rates and tolerances, and emerging evidence suggests there may be physiological-based selection in capture fisheries. By quantifying important physiological rates of a model species, the endemic seabream, Chrysoblephus laticeps, across ecologically relevant thermal gradients and from populations subjected to varying intensities of commercial exploitation, this thesis aimed to 1) provide the first physiologically grounded climate resilience assessment for a South African linefish species, and 2) elucidate whether exploitation can drive populations to less physiologically resilient states in response to climate change. To identify physiologically limiting sea temperatures and to determine if exploitation alters physiological trait distributions, an intermittent flow respirometry experiment was used to test the metabolic response of spatially protected and exploited populations of C. laticeps to acute thermal variability. Exploited populations showed reduced metabolic phenotype diversity, fewer high-performance aerobic scope phenotypes, and a significantly lower aerobic scope curve across all test temperatures. Although both populations maintained a relatively high aerobic scope across a wide thermal range, their metabolic rates were compromised when extreme cold events were simulated (8 °C), suggesting that predicted future increases in upwelling frequency and intensity may be the primary limiting factor in a more thermally variable future ocean. The increment widths of annuli in the otoliths of C. laticeps from contemporary and historic collections were measured, as a proxy for the annual growth rate of exploited and protected populations. Hierarchical mixed models were used to partition growth variation within and among individuals and ascribe growth to intrinsic and extrinsic effects. The best model for the protected population indicated that the growth response of C. laticeps was poorer during years characterised by a high cumulative upwelling intensity, and better during years characterised by higher mean autumn sea surface temperatures. The exploited population growth chronology was too short to identify an extrinsic growth driver. The growth results again highlight the role of thermal variability in modulating the response of C. laticeps to its ambient environment and indicate that the predicted increases in upwelling frequency and intensity may constrain future growth rates of this species. A metabolic index (ϕ), representing the ratio of O2 supply to demand at various temperatures and oxygen concentrations, was estimated for exploited and protected populations of C. laticeps and used to predict future distribution responses. There was no difference in the laboratory calibrations of ϕ between populations, and all data was subsequently combined into a single piecewise (12 °C) calibrated ϕ model. To predict the distribution of C. laticeps, ϕ was projected across a high-resolution ocean model of the South African coastal zone, and a species distribution model implemented using the random forest algorithm and C. laticeps occurrence points. The future distribution of C. laticeps was estimated by predicting trained models across ocean model projections up to 2100. The best predictor of C. laticeps’ current distribution was minimum monthly ϕ and future predictions indicated only a slight range contraction on either edge of C. laticeps’ distribution by 2100. In order to provide policy makers, currently developing climate change management frameworks for South Africa’s ocean, with a usable output, the results of all research chapters were combined into a marine spatial model. The spatial model identified areas where C. laticeps is predicted to be resilient to climate change in terms of physiology, growth and distribution responses, which can then be prioritised for adaptation measures, such as spatial protection from exploitation. While these results are specific to C. laticeps, the methodology developed to identify areas of climate resilience has broad applications across taxa. From a global perspective, perhaps the most salient points to consider from this case study are the evidence of selective exploitation on physiological traits and the importance of environmental variability, rather than long-term mean climate changes, in affecting organism performance. These ideas are congruent with the current paradigm shift in how we think of the ocean, selective fisheries, and how they relate to organism climate resilience.
- Full Text:
- Authors: Duncan, Murray Ian
- Date: 2019
- Subjects: Chrysoblephus laticeps -- Climatic factors , Chrysoblephus laticeps -- Physiology , Sparidae -- South Africa -- Climatic factors , Reef fishes -- South Africa -- Climatic factors , Fish populations -- South Africa -- Climatic factors , Fish populations -- Measurement , Fish populations -- Monitoring , Fisheries -- South Africa -- Environmental aspects , Ocean temperature -- Physiological effect -- South Africa
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/76541 , vital:30599
- Description: The persistence of harvested fish populations in the Anthropocene will be determined, above all, by how they respond to the interacting effects of climate change and fisheries exploitation. Predicting how populations will respond to both these threats is essential for any adaptive and sustainable management strategy. The response of fish populations to climate change is underpinned by physiological rates and tolerances, and emerging evidence suggests there may be physiological-based selection in capture fisheries. By quantifying important physiological rates of a model species, the endemic seabream, Chrysoblephus laticeps, across ecologically relevant thermal gradients and from populations subjected to varying intensities of commercial exploitation, this thesis aimed to 1) provide the first physiologically grounded climate resilience assessment for a South African linefish species, and 2) elucidate whether exploitation can drive populations to less physiologically resilient states in response to climate change. To identify physiologically limiting sea temperatures and to determine if exploitation alters physiological trait distributions, an intermittent flow respirometry experiment was used to test the metabolic response of spatially protected and exploited populations of C. laticeps to acute thermal variability. Exploited populations showed reduced metabolic phenotype diversity, fewer high-performance aerobic scope phenotypes, and a significantly lower aerobic scope curve across all test temperatures. Although both populations maintained a relatively high aerobic scope across a wide thermal range, their metabolic rates were compromised when extreme cold events were simulated (8 °C), suggesting that predicted future increases in upwelling frequency and intensity may be the primary limiting factor in a more thermally variable future ocean. The increment widths of annuli in the otoliths of C. laticeps from contemporary and historic collections were measured, as a proxy for the annual growth rate of exploited and protected populations. Hierarchical mixed models were used to partition growth variation within and among individuals and ascribe growth to intrinsic and extrinsic effects. The best model for the protected population indicated that the growth response of C. laticeps was poorer during years characterised by a high cumulative upwelling intensity, and better during years characterised by higher mean autumn sea surface temperatures. The exploited population growth chronology was too short to identify an extrinsic growth driver. The growth results again highlight the role of thermal variability in modulating the response of C. laticeps to its ambient environment and indicate that the predicted increases in upwelling frequency and intensity may constrain future growth rates of this species. A metabolic index (ϕ), representing the ratio of O2 supply to demand at various temperatures and oxygen concentrations, was estimated for exploited and protected populations of C. laticeps and used to predict future distribution responses. There was no difference in the laboratory calibrations of ϕ between populations, and all data was subsequently combined into a single piecewise (12 °C) calibrated ϕ model. To predict the distribution of C. laticeps, ϕ was projected across a high-resolution ocean model of the South African coastal zone, and a species distribution model implemented using the random forest algorithm and C. laticeps occurrence points. The future distribution of C. laticeps was estimated by predicting trained models across ocean model projections up to 2100. The best predictor of C. laticeps’ current distribution was minimum monthly ϕ and future predictions indicated only a slight range contraction on either edge of C. laticeps’ distribution by 2100. In order to provide policy makers, currently developing climate change management frameworks for South Africa’s ocean, with a usable output, the results of all research chapters were combined into a marine spatial model. The spatial model identified areas where C. laticeps is predicted to be resilient to climate change in terms of physiology, growth and distribution responses, which can then be prioritised for adaptation measures, such as spatial protection from exploitation. While these results are specific to C. laticeps, the methodology developed to identify areas of climate resilience has broad applications across taxa. From a global perspective, perhaps the most salient points to consider from this case study are the evidence of selective exploitation on physiological traits and the importance of environmental variability, rather than long-term mean climate changes, in affecting organism performance. These ideas are congruent with the current paradigm shift in how we think of the ocean, selective fisheries, and how they relate to organism climate resilience.
- Full Text:
The performance and preference of a specialist herbivore, Catorhintha schaffneri (Coreidae), on its polytypic host plant, Pereskia aculeata (Cactaceae)
- Authors: Egbon, Ikponmwosa Nathaniel
- Date: 2019
- Subjects: Insects and biological pest control agents -- South Africa , Pereskia -- Biological control -- South Africa , Cactus -- Biological control -- South Africa , Coreida-- South Africa , Invasive plants -- Biological control -- South Africa , Catorhintha schaffneri
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/68250 , vital:29223
- Description: Plant species moved beyond their natural ranges may be liberated into enemy-free spaces, where they increase resource allocation to fitness, rather than defence against natural enemies, and become invasive as suggested by the Evolution of Increased Competitive Ability (EICA) Hypothesis. Several cacti are notable invaders and are targeted for biological control. The leafy cactus, Pereskia aculeata Miller, introduced into South Africa from South America, has become a target for biological control after becoming invasive. The absence of natural enemies of P. aculeata in the introduced range may be the reason for its invasiveness. This thesis seeks to investigate the role of the evolution of increased competitive ability (enemy release) as the probable driver of P. aculeata’s success, and ascertain how the plant’s intraspecific variation influences the impact, fitness of, and preference by its biological control agent, Catorhintha schaffneri Brailovsky and Garcia (Coreidae), in South Africa. Enemy release and evolution of traits in P. aculeata were examined by quantifying plant growth parameters of fifteen genotypes of P. aculeata from both the native and invaded distribution of the plant. Ten genotypes of P. aculeata were used in testing the effect of agent herbivory (impact and damage) under similar conditions. These studies indicated that most invaded-range genotypes were more vigorous than the native genotypes. Rapid growth may account for the quick access of invasive genotypes of P. aculeata to tree canopies. Catorhintha schaffneri damage varied between genotypes but differences in the damage and impact from the agent could not be explained by whether the plant originated in the introduced or native distribution. In sum, while the growth of the invasive genotypes largely conforms to the EICA hypothesis, the impact of C. schaffneri did not support the hypothesis. The influence of host variation in P. aculeata on the fitness of C. schaffneri within the context of local adaptation to plant genotypes from different localities was tested using agent survival, stage-specific and total developmental time, and the extent of damage to ten host genotypes. Maw’s Host Suitability Index (HIS) and Dobie’s Susceptibility Index (DSI) showed the preference by and performance of C. schaffneri on the different genotypes of the plant. Catorhintha schaffneri survived to the adult stage on 70% of genotypes tested. Evidence consistent with the assumption that C. schaffneri would be fitter on the native genotypes than the invasive genotypes due to local adaptation was not found. In addition, there was no evidence in support of fitter agents on the invasive genotypes than on the native genotypes as proposed by EICA hypothesis. Catorhintha schaffneri developed equally well on the invasive genotypes of P. aculeata as on the native genotypes. To establish whether host variation would affect diet selection by C. schaffneri, both nymphs and adults were examined in paired-choice and multiple-choice trials. The nymphs and adults chose their hosts regardless of host genotype differences. The agent may be good at selecting good succulent shoots from bad shoots, but is incapable of distinguishing a good host genotype from a poorer one. This thesis shows, therefore, that P. aculeata and its array of genotypes in South Africa could be effectively controlled by C. schaffneri, as it has the potential to suitably utilise and impact the different genotypes of the weed in South Africa with neither any demonstrable preference nor local adaptation for the native genotypes. Consequently, the use of C. schaffneri, as a biological control agent in the weed biological control programme of P. aculeata remains promising, as the agent is insensitive to the intraspecific variation of the invasive host plants.
- Full Text:
- Authors: Egbon, Ikponmwosa Nathaniel
- Date: 2019
- Subjects: Insects and biological pest control agents -- South Africa , Pereskia -- Biological control -- South Africa , Cactus -- Biological control -- South Africa , Coreida-- South Africa , Invasive plants -- Biological control -- South Africa , Catorhintha schaffneri
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/68250 , vital:29223
- Description: Plant species moved beyond their natural ranges may be liberated into enemy-free spaces, where they increase resource allocation to fitness, rather than defence against natural enemies, and become invasive as suggested by the Evolution of Increased Competitive Ability (EICA) Hypothesis. Several cacti are notable invaders and are targeted for biological control. The leafy cactus, Pereskia aculeata Miller, introduced into South Africa from South America, has become a target for biological control after becoming invasive. The absence of natural enemies of P. aculeata in the introduced range may be the reason for its invasiveness. This thesis seeks to investigate the role of the evolution of increased competitive ability (enemy release) as the probable driver of P. aculeata’s success, and ascertain how the plant’s intraspecific variation influences the impact, fitness of, and preference by its biological control agent, Catorhintha schaffneri Brailovsky and Garcia (Coreidae), in South Africa. Enemy release and evolution of traits in P. aculeata were examined by quantifying plant growth parameters of fifteen genotypes of P. aculeata from both the native and invaded distribution of the plant. Ten genotypes of P. aculeata were used in testing the effect of agent herbivory (impact and damage) under similar conditions. These studies indicated that most invaded-range genotypes were more vigorous than the native genotypes. Rapid growth may account for the quick access of invasive genotypes of P. aculeata to tree canopies. Catorhintha schaffneri damage varied between genotypes but differences in the damage and impact from the agent could not be explained by whether the plant originated in the introduced or native distribution. In sum, while the growth of the invasive genotypes largely conforms to the EICA hypothesis, the impact of C. schaffneri did not support the hypothesis. The influence of host variation in P. aculeata on the fitness of C. schaffneri within the context of local adaptation to plant genotypes from different localities was tested using agent survival, stage-specific and total developmental time, and the extent of damage to ten host genotypes. Maw’s Host Suitability Index (HIS) and Dobie’s Susceptibility Index (DSI) showed the preference by and performance of C. schaffneri on the different genotypes of the plant. Catorhintha schaffneri survived to the adult stage on 70% of genotypes tested. Evidence consistent with the assumption that C. schaffneri would be fitter on the native genotypes than the invasive genotypes due to local adaptation was not found. In addition, there was no evidence in support of fitter agents on the invasive genotypes than on the native genotypes as proposed by EICA hypothesis. Catorhintha schaffneri developed equally well on the invasive genotypes of P. aculeata as on the native genotypes. To establish whether host variation would affect diet selection by C. schaffneri, both nymphs and adults were examined in paired-choice and multiple-choice trials. The nymphs and adults chose their hosts regardless of host genotype differences. The agent may be good at selecting good succulent shoots from bad shoots, but is incapable of distinguishing a good host genotype from a poorer one. This thesis shows, therefore, that P. aculeata and its array of genotypes in South Africa could be effectively controlled by C. schaffneri, as it has the potential to suitably utilise and impact the different genotypes of the weed in South Africa with neither any demonstrable preference nor local adaptation for the native genotypes. Consequently, the use of C. schaffneri, as a biological control agent in the weed biological control programme of P. aculeata remains promising, as the agent is insensitive to the intraspecific variation of the invasive host plants.
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The trophic and spatial ecology of a sympatric dasyatid community at a remote Atoll, Seychelles
- Authors: Elston, Chantel
- Date: 2019
- Subjects: Dasyatidae -- Seychelles -- Ecology , Rays (Fishes) -- Seychelles -- Ecology , Ecology -- Seychelles , Dasyatidae -- Seychelles -- Conservation , Pastinachus sephen , Urogymnus granulatus , Urogymnus asperrimus
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/95756 , vital:31196 , DOI https://doi.org/10.21504/10962/95756
- Description: Batoid populations are declining globally but the paucity of information makes management or conservation efforts difficult. Additionally, batoids are mesopredators and are hypothesised to play important ecological roles, but a comprehensive understanding of these roles is also limited. Therefore, information on batoid habitat use, foraging ecology, and resource partitioning is needed. St. Joseph Atoll is a relatively pristine ecosystem that hosts a sympatric dasyatid community (Pastinachus sephen, Urogymnus granulatus, and U. asperrimus). Passive acoustic telemetry identified high levels of long-term site affinity by both juvenile and adult dasyatids to St. Joseph Atoll. Dispersal from the atoll by larger juveniles was also evident. Juveniles displayed restricted horizontal movements in the atoll, but the extent of these movements differed seasonally. Stomach content and stable isotope analyses identified inter-specific prey partitioning (P. sephen juveniles were mollusc specialists and U. granulatus juveniles were crustacean specialists) and intra-specific prey partitioning. Juveniles were reliant upon a seagrass-based food web, whereas adults were reliant on phytoplankton-based food web. Adults fed at higher trophic levels compared to juveniles (mean of 4.6 and 3.4 respectively). Juvenile dasyatids preferentially selected the shallow reef at habitat of the atoll, where there was no evidence for inter-specific habitat partitioning (individuals co-occurred randomly with con-and hetero-specifics). Conversely, resident adults were more reliant on the deeper lagoon. Juveniles selected the reef at habitat likely because it provided refuge from predation and foraging opportunities. However, juveniles were also detected in the lagoon habitat and this appeared to be necessitated by physical factors as they were detected more frequently in the lagoon at low tides and when temperatures on the reef fats became too warm or too cold. All results together suggest that St. Joseph Atoll is a nursery area for these dasyatids. Juveniles may be limited by resources as prey was partitioned between species. However, top-down control by larger sharks was likely a significant influence on habitat selection, as was the physical effects of tide and temperature. Finally, St. Joseph Atoll is suitable for the designation of a Marine Protected Area, which would likely confer high conservation benefits to this dasyatid community.
- Full Text:
- Authors: Elston, Chantel
- Date: 2019
- Subjects: Dasyatidae -- Seychelles -- Ecology , Rays (Fishes) -- Seychelles -- Ecology , Ecology -- Seychelles , Dasyatidae -- Seychelles -- Conservation , Pastinachus sephen , Urogymnus granulatus , Urogymnus asperrimus
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/95756 , vital:31196 , DOI https://doi.org/10.21504/10962/95756
- Description: Batoid populations are declining globally but the paucity of information makes management or conservation efforts difficult. Additionally, batoids are mesopredators and are hypothesised to play important ecological roles, but a comprehensive understanding of these roles is also limited. Therefore, information on batoid habitat use, foraging ecology, and resource partitioning is needed. St. Joseph Atoll is a relatively pristine ecosystem that hosts a sympatric dasyatid community (Pastinachus sephen, Urogymnus granulatus, and U. asperrimus). Passive acoustic telemetry identified high levels of long-term site affinity by both juvenile and adult dasyatids to St. Joseph Atoll. Dispersal from the atoll by larger juveniles was also evident. Juveniles displayed restricted horizontal movements in the atoll, but the extent of these movements differed seasonally. Stomach content and stable isotope analyses identified inter-specific prey partitioning (P. sephen juveniles were mollusc specialists and U. granulatus juveniles were crustacean specialists) and intra-specific prey partitioning. Juveniles were reliant upon a seagrass-based food web, whereas adults were reliant on phytoplankton-based food web. Adults fed at higher trophic levels compared to juveniles (mean of 4.6 and 3.4 respectively). Juvenile dasyatids preferentially selected the shallow reef at habitat of the atoll, where there was no evidence for inter-specific habitat partitioning (individuals co-occurred randomly with con-and hetero-specifics). Conversely, resident adults were more reliant on the deeper lagoon. Juveniles selected the reef at habitat likely because it provided refuge from predation and foraging opportunities. However, juveniles were also detected in the lagoon habitat and this appeared to be necessitated by physical factors as they were detected more frequently in the lagoon at low tides and when temperatures on the reef fats became too warm or too cold. All results together suggest that St. Joseph Atoll is a nursery area for these dasyatids. Juveniles may be limited by resources as prey was partitioned between species. However, top-down control by larger sharks was likely a significant influence on habitat selection, as was the physical effects of tide and temperature. Finally, St. Joseph Atoll is suitable for the designation of a Marine Protected Area, which would likely confer high conservation benefits to this dasyatid community.
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