Application of quality by design principles for optimizing process variables of Extrusion and Spheronization of a Captopril Pellet Formulation:
- Veerubhotla, Krishna, Walker, Roderick B
- Authors: Veerubhotla, Krishna , Walker, Roderick B
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/178312 , vital:40098 , DOI: 10.36468/pharmaceutical-sciences.624
- Description: Product development using quality by design is a proactive and risk-based approach that shifts the manufacturing process from empirical to science-based. Risk assessment was performed to identify and analyse risk areas for the manufacture of captopril pellets. Twelve experimental runs were performed using a Plackett-Burman screening design. Pareto plots revealed the effect of formulation and process variables on the responses monitored and facilitated the identification of the most critical parameters for optimization of the formulation. A response surface methodology approach in conjunction with a central composite design was used to optimize the Eudragit® RL 30D (15-30 ml), microcrystalline cellulose (20-40 % w/w), sodium starch glycolate (2-5 % w/w) and spheronizer speed (650-1050 rpm).
- Full Text:
- Date Issued: 2020
- Authors: Veerubhotla, Krishna , Walker, Roderick B
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/178312 , vital:40098 , DOI: 10.36468/pharmaceutical-sciences.624
- Description: Product development using quality by design is a proactive and risk-based approach that shifts the manufacturing process from empirical to science-based. Risk assessment was performed to identify and analyse risk areas for the manufacture of captopril pellets. Twelve experimental runs were performed using a Plackett-Burman screening design. Pareto plots revealed the effect of formulation and process variables on the responses monitored and facilitated the identification of the most critical parameters for optimization of the formulation. A response surface methodology approach in conjunction with a central composite design was used to optimize the Eudragit® RL 30D (15-30 ml), microcrystalline cellulose (20-40 % w/w), sodium starch glycolate (2-5 % w/w) and spheronizer speed (650-1050 rpm).
- Full Text:
- Date Issued: 2020
Development and Validation of a Stability-indicating RP-HPLC Method Using Quality by Design for Estimating Captopril
- Veerubhotla, Krishna, Walker, Roderick B
- Authors: Veerubhotla, Krishna , Walker, Roderick B
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/183525 , vital:44003 , xlink:href="10.4172/pharmaceutical-sciences.1000478"
- Description: The applicability of a quality by design framework for the development of a sensitive, simple and selective, stability-indicating reversed-phase high-performance liquid chromatography analytical method for the analysis of captopril was investigated. Design of experiments using a central composite design approach was used for method development. Twenty experimental runs were performed with acetonitrile content ranging between 28 and 36 % v/v, pH from 2.8 to 3.6 and temperature between 22° and 32°. The experimental data obtained was used to derive a quadratic model for the retention time of captopril. The optimized method produced sharp peaks with good resolution (>2) for captopril and the internal standard with retention times of 3.1 and 6.2 min, respectively. The experimental data revealed that acetonitrile content in the mobile phase and pH are significant factors that affect the retention time and resolution of captopril. Normal probability plots revealed that the residual and predicted data fall approximately on a straight line, indicating that the experimental error for these studies was evenly distributed suggesting that the model could be used to navigate the design space. This approach is useful to expedite method development and optimization activities in analytical laboratories.
- Full Text:
- Date Issued: 2019
- Authors: Veerubhotla, Krishna , Walker, Roderick B
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/183525 , vital:44003 , xlink:href="10.4172/pharmaceutical-sciences.1000478"
- Description: The applicability of a quality by design framework for the development of a sensitive, simple and selective, stability-indicating reversed-phase high-performance liquid chromatography analytical method for the analysis of captopril was investigated. Design of experiments using a central composite design approach was used for method development. Twenty experimental runs were performed with acetonitrile content ranging between 28 and 36 % v/v, pH from 2.8 to 3.6 and temperature between 22° and 32°. The experimental data obtained was used to derive a quadratic model for the retention time of captopril. The optimized method produced sharp peaks with good resolution (>2) for captopril and the internal standard with retention times of 3.1 and 6.2 min, respectively. The experimental data revealed that acetonitrile content in the mobile phase and pH are significant factors that affect the retention time and resolution of captopril. Normal probability plots revealed that the residual and predicted data fall approximately on a straight line, indicating that the experimental error for these studies was evenly distributed suggesting that the model could be used to navigate the design space. This approach is useful to expedite method development and optimization activities in analytical laboratories.
- Full Text:
- Date Issued: 2019
The legalisation of prostitution in South Africa
- Authors: Vaveki, Vuyani Patrick
- Date: 2019
- Subjects: Prostitution|xLaw and legislation , Sex and law -- South Africa Prostitution -- South Africa Women -- Legal status, laws, etc
- Language: English
- Type: Thesis , Masters , LLM
- Identifier: http://hdl.handle.net/10948/43698 , vital:37034
- Description: Prostitution or Sex work has been a crime in the country for a number of decades. In earlier years sex work was not explicitly crminalised and the government relied on various laws to regulate and deal with sex work. With the passage of time sex work was formally regulated and dealt with specifically as a criminal offence by legislation. Those legislative measures still exist to ensure that sex work remains a crime in South Africa. Courts have on a number of occasion been tasked to consider the status of sex workers in the context of the human rights provided for by the Constitution of the Republic (both the interim and the final). In the two seminal cases of S v Jordan and others and Kylie v CCMA the courts approached the status of sex workers on the basis that even sex workers are entitled to the human rights enshrined in the Constitution. The Constitutional Court in Jordan, however refused to decriminalise sex work for those purposes holding that it is for the legislature to decide the issue of decriminalisation. Various interest groups have lobbied for the decriminalisation of sex work in order to give meaning to Constitutional rights of sex workers. The criminalisation of sex work appears to be a case of the state legislating morality and interfering with private individual matters. With a bad history of state interference in private affairs of individuals this practise should be guarded against in the Constitutional dispensation. Criminal law as such should have no application in private instances that cause no harm to any other person or state interests. It appears that the continued criminalisation of sex work is increasingly appearing to be without proper justification and as such it is recommended that the country adopts the New Zealand model of decriminalisation. This will ensure that the rights of sex workers are duly respected.
- Full Text:
- Date Issued: 2019
- Authors: Vaveki, Vuyani Patrick
- Date: 2019
- Subjects: Prostitution|xLaw and legislation , Sex and law -- South Africa Prostitution -- South Africa Women -- Legal status, laws, etc
- Language: English
- Type: Thesis , Masters , LLM
- Identifier: http://hdl.handle.net/10948/43698 , vital:37034
- Description: Prostitution or Sex work has been a crime in the country for a number of decades. In earlier years sex work was not explicitly crminalised and the government relied on various laws to regulate and deal with sex work. With the passage of time sex work was formally regulated and dealt with specifically as a criminal offence by legislation. Those legislative measures still exist to ensure that sex work remains a crime in South Africa. Courts have on a number of occasion been tasked to consider the status of sex workers in the context of the human rights provided for by the Constitution of the Republic (both the interim and the final). In the two seminal cases of S v Jordan and others and Kylie v CCMA the courts approached the status of sex workers on the basis that even sex workers are entitled to the human rights enshrined in the Constitution. The Constitutional Court in Jordan, however refused to decriminalise sex work for those purposes holding that it is for the legislature to decide the issue of decriminalisation. Various interest groups have lobbied for the decriminalisation of sex work in order to give meaning to Constitutional rights of sex workers. The criminalisation of sex work appears to be a case of the state legislating morality and interfering with private individual matters. With a bad history of state interference in private affairs of individuals this practise should be guarded against in the Constitutional dispensation. Criminal law as such should have no application in private instances that cause no harm to any other person or state interests. It appears that the continued criminalisation of sex work is increasingly appearing to be without proper justification and as such it is recommended that the country adopts the New Zealand model of decriminalisation. This will ensure that the rights of sex workers are duly respected.
- Full Text:
- Date Issued: 2019
The prediction of, and changes in,medullated fibre levels when processing mohair into top
- Authors: Van Zyl, Andreas Marius
- Date: 2019
- Subjects: Mohair Industry -- South Africa , Textile Fibers Testing
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/45767 , vital:38962
- Description: The prediction of, and changes in, medullated fibre levels during early stage processing of mohair, from greasy to top, have been studied. Commercial lots, representative of the South African and Basuto mohair clips, covering a wide range of properties, with respect to objectionable medullated (kemp type) fibres, length and fibre diameter, were sampled for testing at three different processing stages, viz. greasy, preparatory gilled sliver, and top. All samples were tested with an Optical Fibre Diameter Analyser (OFDA100) for medullated- and fibre diameter related properties. Various statistical analyses were conducted to determine the most significant correlations and best prediction of changes in medullated fibre levels, during processing. As expected, the medullated fibre levels of the Basuto lots were much higher than those of the Cape lots. Moreover, the inclusion or exclusion of flat fibres, in combination with other medullated fibres, resulted in significant differences in the outcome of some of the statistical analysis. It was found that flat fibre levels were highly correlated with the standard deviation of fibre diameter at all processing stages, and also, the greasy standard deviation of fibre diameter was the best predictor of flat fibre levels in the top. Further, the percentage reduction in flat fibres, from greasy to preparatory gilled sliver, was more than double that of the reduction in flat fibres from preparatory gilled sliver to top. Similarly, the percentage reduction in objectionable medullated (including flat) fibres, from greasy to preparatory gilled sliver, was about 1.7 times more than that of the reduction from preparatory gilled sliver to top.
- Full Text:
- Date Issued: 2019
- Authors: Van Zyl, Andreas Marius
- Date: 2019
- Subjects: Mohair Industry -- South Africa , Textile Fibers Testing
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/45767 , vital:38962
- Description: The prediction of, and changes in, medullated fibre levels during early stage processing of mohair, from greasy to top, have been studied. Commercial lots, representative of the South African and Basuto mohair clips, covering a wide range of properties, with respect to objectionable medullated (kemp type) fibres, length and fibre diameter, were sampled for testing at three different processing stages, viz. greasy, preparatory gilled sliver, and top. All samples were tested with an Optical Fibre Diameter Analyser (OFDA100) for medullated- and fibre diameter related properties. Various statistical analyses were conducted to determine the most significant correlations and best prediction of changes in medullated fibre levels, during processing. As expected, the medullated fibre levels of the Basuto lots were much higher than those of the Cape lots. Moreover, the inclusion or exclusion of flat fibres, in combination with other medullated fibres, resulted in significant differences in the outcome of some of the statistical analysis. It was found that flat fibre levels were highly correlated with the standard deviation of fibre diameter at all processing stages, and also, the greasy standard deviation of fibre diameter was the best predictor of flat fibre levels in the top. Further, the percentage reduction in flat fibres, from greasy to preparatory gilled sliver, was more than double that of the reduction in flat fibres from preparatory gilled sliver to top. Similarly, the percentage reduction in objectionable medullated (including flat) fibres, from greasy to preparatory gilled sliver, was about 1.7 times more than that of the reduction from preparatory gilled sliver to top.
- Full Text:
- Date Issued: 2019
A sociological investigation of conflict and its effects on employees performance at the Windhoek training centre
- Authors: Van Wyk, Deria
- Date: 2019
- Subjects: Conflict Management-- Namibia , Employee motivation
- Language: English
- Type: Thesis , Masters , Degree
- Identifier: http://hdl.handle.net/10948/45734 , vital:38959
- Description: Conflicts are an inevitable part of organizational life since the goals of different stakeholders such as managers and staff are often incompatible. Conflict in the workplace can be detrimental to progress, efficiency and performance. In order to create a productive workforce, effective conflict resolution strategies need to be implemented. This has often led to workplace harmony and productivity. If not managed effectively and discreetly, workplace relationships will suffer and consequently will result in disunity and chaos. A cohesive work environment promotes employee performance and organizational effectiveness. Poorly managing conflicts in the workplace can have adverse effects on the level and frequency of future conflicts and can negatively affect productivity, job performance. The purpose of this study is to investigate the causes and effects of conflict at the Windhoek Vocational Training Centre and to find workable solutions to manage the conflict in an effort to improve job satisfaction and employee performance. Performance of Vocational Instructors at the WVTC are not always up to standard due to certain factors. This study aims to identify these factors and find solutions to address these problems. The study has followed a qualitative approach which included individual interviews using an interview guide. Secondary sources which ranges from journal articles and scholarly books were used as per social sciences research requirements
- Full Text:
- Date Issued: 2019
- Authors: Van Wyk, Deria
- Date: 2019
- Subjects: Conflict Management-- Namibia , Employee motivation
- Language: English
- Type: Thesis , Masters , Degree
- Identifier: http://hdl.handle.net/10948/45734 , vital:38959
- Description: Conflicts are an inevitable part of organizational life since the goals of different stakeholders such as managers and staff are often incompatible. Conflict in the workplace can be detrimental to progress, efficiency and performance. In order to create a productive workforce, effective conflict resolution strategies need to be implemented. This has often led to workplace harmony and productivity. If not managed effectively and discreetly, workplace relationships will suffer and consequently will result in disunity and chaos. A cohesive work environment promotes employee performance and organizational effectiveness. Poorly managing conflicts in the workplace can have adverse effects on the level and frequency of future conflicts and can negatively affect productivity, job performance. The purpose of this study is to investigate the causes and effects of conflict at the Windhoek Vocational Training Centre and to find workable solutions to manage the conflict in an effort to improve job satisfaction and employee performance. Performance of Vocational Instructors at the WVTC are not always up to standard due to certain factors. This study aims to identify these factors and find solutions to address these problems. The study has followed a qualitative approach which included individual interviews using an interview guide. Secondary sources which ranges from journal articles and scholarly books were used as per social sciences research requirements
- Full Text:
- Date Issued: 2019
Plants, people, and place: complex, mutualistic, and co-evolving global patterns through time
- Authors: Van Wijk, Yvette Ethné
- Date: 2019
- Subjects: Ethnobotany -- South Africa -- Western Cape , Khoisan (African people) -- Ethnobotany , Human-plant relationships -- South Africa -- Western Cape , Plants -- Classification -- South Africa -- Western Cape , Plant remains (Archaeology) -- South Africa -- Western Cape , Ethnoscience -- South Africa -- Western Cape , Regression analysis
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/76575 , vital:30609
- Description: My thesis studies and analyses the suite of distinctive plant taxa which persist in small patches of vegetation growing in close association with archaeological habitation sites in the southern Cape, South Africa. The unexpected correlation and overlap between botanical taxa collected at 75 site complexes, and ethnobotanical data collected in collaboration with modern Khoi-San communities in the same area, is explored and interrogated. Although sparse, reports of the same suite of taxa recovered from archaeological excavations in the Cape provinces provides depth of time to the study, linking the past to the present. The three-way correlation of a suite of plants closely associated with humans and habitation sites through time, allows for triangulation of the data in order to validate and cross verify the results using more than one frame of reference. Both the plants and the knowledge about their uses have persisted in spite of historical attrition, and alienation of land and language, suffered by the Khoi-San over the past 300 years. Drawing on a large body of primary and secondary data, and using an interdisciplinary, abductive and pragmatic mixed methods approach, a pattern can be traced throughout Africa and globally. Regression analysis strongly indicates that the most ubiquitous taxa were selected for a purpose and are not randomly present in association with humans. Botanical, anthropological, and archaeological studies seldom focus on the inter-connectedness of people and plants at the sites they inhabited. Very little research into modern vegetation in close association with the sites has been undertaken, and vegetation mapping has not captured the occurrence of these site-specific small vegetation patches recorded during my surveys. The topographically, geologically, and vegetatively complex and varied southern Cape, and greater Cape area, is extremely rich in archaeological sites and history. This study suggests that the value of site-specific plant taxa to humans throughout the aeons of pre-agricultural history, persists into the present. Due to tolerance of a broad range of climatic and environmental variables, there is value in the study of these ancient and neglected useful plants in the face of climate change. That this vegetation is so closely associated with archaeological sites of cultural and historic importance confers an urgency to recognising the existence and significance of the distinctive and possibly anthropogenic vegetation surrounding the sites.
- Full Text:
- Date Issued: 2019
- Authors: Van Wijk, Yvette Ethné
- Date: 2019
- Subjects: Ethnobotany -- South Africa -- Western Cape , Khoisan (African people) -- Ethnobotany , Human-plant relationships -- South Africa -- Western Cape , Plants -- Classification -- South Africa -- Western Cape , Plant remains (Archaeology) -- South Africa -- Western Cape , Ethnoscience -- South Africa -- Western Cape , Regression analysis
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/76575 , vital:30609
- Description: My thesis studies and analyses the suite of distinctive plant taxa which persist in small patches of vegetation growing in close association with archaeological habitation sites in the southern Cape, South Africa. The unexpected correlation and overlap between botanical taxa collected at 75 site complexes, and ethnobotanical data collected in collaboration with modern Khoi-San communities in the same area, is explored and interrogated. Although sparse, reports of the same suite of taxa recovered from archaeological excavations in the Cape provinces provides depth of time to the study, linking the past to the present. The three-way correlation of a suite of plants closely associated with humans and habitation sites through time, allows for triangulation of the data in order to validate and cross verify the results using more than one frame of reference. Both the plants and the knowledge about their uses have persisted in spite of historical attrition, and alienation of land and language, suffered by the Khoi-San over the past 300 years. Drawing on a large body of primary and secondary data, and using an interdisciplinary, abductive and pragmatic mixed methods approach, a pattern can be traced throughout Africa and globally. Regression analysis strongly indicates that the most ubiquitous taxa were selected for a purpose and are not randomly present in association with humans. Botanical, anthropological, and archaeological studies seldom focus on the inter-connectedness of people and plants at the sites they inhabited. Very little research into modern vegetation in close association with the sites has been undertaken, and vegetation mapping has not captured the occurrence of these site-specific small vegetation patches recorded during my surveys. The topographically, geologically, and vegetatively complex and varied southern Cape, and greater Cape area, is extremely rich in archaeological sites and history. This study suggests that the value of site-specific plant taxa to humans throughout the aeons of pre-agricultural history, persists into the present. Due to tolerance of a broad range of climatic and environmental variables, there is value in the study of these ancient and neglected useful plants in the face of climate change. That this vegetation is so closely associated with archaeological sites of cultural and historic importance confers an urgency to recognising the existence and significance of the distinctive and possibly anthropogenic vegetation surrounding the sites.
- Full Text:
- Date Issued: 2019
The social construction of a racial identity on social media sites: a narrative inquiry
- Authors: van Vught, Chandré
- Date: 2019
- Subjects: Construction of Racial Identity , Colored people (South Africa) -- Psychological aspects Internet users -- Psychology Cyberspace -- Psychological aspects Social psychology
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10948/44169 , vital:37122
- Description: The present study aimed to enhance the understanding of the social construction of Coloured identity on social media sites from the perspective of individuals who identify themselves as Coloured. Furthermore, the study explored how the participants’ engagement on social media sites influenced the construction of their online identities. A qualitative research approach was utilised with narrative inquiry as the research design to explore the perceptions that the participants held about identity, and in particular about Coloured identity. The aim of the study was achieved as six participants were recruited through purposive and snowball sampling. The data collection method was individual semi-structured interviews, with the exception of one interview conducted with two participants. The findings were conceptualised according to credible literature sources and theories. Through the process of thematic analysis, the research yielded valuable findings. The study found that there was strong objection by one participant and ambivalence by other participants about the use of the term Coloured, and its association with identity due to the derogatory associations which stems from its origin. It was found that social media users who identify themselves as Coloured construct their online identities in such a way that it is consistent with their narration of their offline identities. Moreover, minimal importance was placed on racial identity online, as well as offline. However, the participants acknowledged that Coloured identity had predominantly been portrayed in accordance with negative stereotypes. The negative portrayals of Coloured identity were challenged, as these portrayals were not truthful to how the participants were socialised. Furthermore, there was a consensus among the participants that dominant narratives about Coloured identity must be de-constructed and re-constructed. As a social justice study, the present study challenged dominant constructs about Coloured identity in South Africa and is thus able to contribute towards heritage studies in vi South Africa. The significance of heritage studies in South Africa is paramount, as identity and heritage are interlinked. The study created meaning about the participants’ online identities, and thus created meaning of who they are on their social media platforms.
- Full Text:
- Date Issued: 2019
- Authors: van Vught, Chandré
- Date: 2019
- Subjects: Construction of Racial Identity , Colored people (South Africa) -- Psychological aspects Internet users -- Psychology Cyberspace -- Psychological aspects Social psychology
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10948/44169 , vital:37122
- Description: The present study aimed to enhance the understanding of the social construction of Coloured identity on social media sites from the perspective of individuals who identify themselves as Coloured. Furthermore, the study explored how the participants’ engagement on social media sites influenced the construction of their online identities. A qualitative research approach was utilised with narrative inquiry as the research design to explore the perceptions that the participants held about identity, and in particular about Coloured identity. The aim of the study was achieved as six participants were recruited through purposive and snowball sampling. The data collection method was individual semi-structured interviews, with the exception of one interview conducted with two participants. The findings were conceptualised according to credible literature sources and theories. Through the process of thematic analysis, the research yielded valuable findings. The study found that there was strong objection by one participant and ambivalence by other participants about the use of the term Coloured, and its association with identity due to the derogatory associations which stems from its origin. It was found that social media users who identify themselves as Coloured construct their online identities in such a way that it is consistent with their narration of their offline identities. Moreover, minimal importance was placed on racial identity online, as well as offline. However, the participants acknowledged that Coloured identity had predominantly been portrayed in accordance with negative stereotypes. The negative portrayals of Coloured identity were challenged, as these portrayals were not truthful to how the participants were socialised. Furthermore, there was a consensus among the participants that dominant narratives about Coloured identity must be de-constructed and re-constructed. As a social justice study, the present study challenged dominant constructs about Coloured identity in South Africa and is thus able to contribute towards heritage studies in vi South Africa. The significance of heritage studies in South Africa is paramount, as identity and heritage are interlinked. The study created meaning about the participants’ online identities, and thus created meaning of who they are on their social media platforms.
- Full Text:
- Date Issued: 2019
The relationship between perceived ethical leadership and employee life-satisfaction in South Africa
- Authors: van Rooyen, Uné
- Date: 2019
- Subjects: Leadership -- Moral and ethical aspects , Leadership Business ethics Social responsibility of business
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: http://hdl.handle.net/10948/44100 , vital:37110
- Description: Leadership behaviour has a significant impact on follower outcomes. How leaders are perceived in terms of ethical leadership and integrity may have an impact on follower well-being. This non-experimental, correlational study aimed to determine the relationships between Ethical Leadership, employee Life-satisfaction and Job-satisfaction in South Africa. Perceived Leader Integrity was used as an indicator of Ethical Leadership. Employing the survey method, Ethical Leadership was measured with the Perceived Leadership Integrity Scale (PLIS), Life-satisfaction was measured with the Satisfaction with Life Scale (SWLS) and Job-satisfaction was measured with the Michigan Organisational Assessment Questionnaire Jobsatisfaction Subscale (MOAQ-JSS). The sample consisted of lower and middle managers in various organisations across different geographical locations in South Africa. Data was analysed using descriptive and inferential statistics, including Cronbach’s alpha testing, Person Product Moment correlation calculations as well as Independent samples T-tests and ANOVA statistics. The results indicated a positive, yet negligible relationship between Perceived Leader Integrity and Life-satisfaction, and a fair positive relationship between Perceived Leader Integrity and Job-satisfaction, as well as between Lifesatisfaction and Job-satisfaction. Despite several limitations, the study contributes to the current body of knowledge regarding leadership and well-being, specifically in a South African context. Recommendations for future research include cultural considerations, and more specific populations groups, among others.
- Full Text:
- Date Issued: 2019
The relationship between perceived ethical leadership and employee life-satisfaction in South Africa
- Authors: van Rooyen, Uné
- Date: 2019
- Subjects: Leadership -- Moral and ethical aspects , Leadership Business ethics Social responsibility of business
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: http://hdl.handle.net/10948/44100 , vital:37110
- Description: Leadership behaviour has a significant impact on follower outcomes. How leaders are perceived in terms of ethical leadership and integrity may have an impact on follower well-being. This non-experimental, correlational study aimed to determine the relationships between Ethical Leadership, employee Life-satisfaction and Job-satisfaction in South Africa. Perceived Leader Integrity was used as an indicator of Ethical Leadership. Employing the survey method, Ethical Leadership was measured with the Perceived Leadership Integrity Scale (PLIS), Life-satisfaction was measured with the Satisfaction with Life Scale (SWLS) and Job-satisfaction was measured with the Michigan Organisational Assessment Questionnaire Jobsatisfaction Subscale (MOAQ-JSS). The sample consisted of lower and middle managers in various organisations across different geographical locations in South Africa. Data was analysed using descriptive and inferential statistics, including Cronbach’s alpha testing, Person Product Moment correlation calculations as well as Independent samples T-tests and ANOVA statistics. The results indicated a positive, yet negligible relationship between Perceived Leader Integrity and Life-satisfaction, and a fair positive relationship between Perceived Leader Integrity and Job-satisfaction, as well as between Lifesatisfaction and Job-satisfaction. Despite several limitations, the study contributes to the current body of knowledge regarding leadership and well-being, specifically in a South African context. Recommendations for future research include cultural considerations, and more specific populations groups, among others.
- Full Text:
- Date Issued: 2019
Systematic review of rural health development research in South Africa
- Authors: van Rooyen, Rize Dorothea
- Date: 2019
- Subjects: Rural health services -- South Africa , Rural development -- South Africa Health -- Research -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10948/44112 , vital:37112
- Description: The challenges presented by the contextual realities of rurality on the South African rural health care system are important to the understanding of the poor health outcomes of these populations. Nonetheless, much research has been done on South African rural health. The vast amount of information, studies and policies regarding South African rural health, and its development made it ideal to be studied by systematic review. This systematic review through its adaption of a mixed methods approach, reviewed a sample of the South African rural health development research outputs between 2013 and 2018, in addition to practitioner-led research and policies. Twelve key systematic review steps were developed to assist in executing the research. In addition, a complete research protocol was part of the systematic review steps. The review protocol indicated the strategies utilised in the scoping searches, data collection and synthesis processes of the review. The findings of this research consisted of three synthesis processes. The first synthesis consisted of the presentation of the qualitative findings and the interpretation thereof. The second synthesis process compared the key themes extracted from the data outputs to those extracted from the grey literature, and the third synthesis integrated the quantitative and qualitative findings into a single review. The review found that although research and practice were aligned to an extent, there were important areas of research, which had been largely overlooked. These included areas such as participation of advocacy, training and education as well as rural-proofing. It further showed that academic research in the field of rural health development relied heavily on participant dependent research methods thereby limiting the exposure of researchers to the phenomena being studied. This review’s methodology and protocol could serve as a guideline for future researchers. The prioritisation of rural health needs and the inclusion of rurality as a variable in South African healthcare policy and strategy is essential in health development research.
- Full Text:
- Date Issued: 2019
- Authors: van Rooyen, Rize Dorothea
- Date: 2019
- Subjects: Rural health services -- South Africa , Rural development -- South Africa Health -- Research -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10948/44112 , vital:37112
- Description: The challenges presented by the contextual realities of rurality on the South African rural health care system are important to the understanding of the poor health outcomes of these populations. Nonetheless, much research has been done on South African rural health. The vast amount of information, studies and policies regarding South African rural health, and its development made it ideal to be studied by systematic review. This systematic review through its adaption of a mixed methods approach, reviewed a sample of the South African rural health development research outputs between 2013 and 2018, in addition to practitioner-led research and policies. Twelve key systematic review steps were developed to assist in executing the research. In addition, a complete research protocol was part of the systematic review steps. The review protocol indicated the strategies utilised in the scoping searches, data collection and synthesis processes of the review. The findings of this research consisted of three synthesis processes. The first synthesis consisted of the presentation of the qualitative findings and the interpretation thereof. The second synthesis process compared the key themes extracted from the data outputs to those extracted from the grey literature, and the third synthesis integrated the quantitative and qualitative findings into a single review. The review found that although research and practice were aligned to an extent, there were important areas of research, which had been largely overlooked. These included areas such as participation of advocacy, training and education as well as rural-proofing. It further showed that academic research in the field of rural health development relied heavily on participant dependent research methods thereby limiting the exposure of researchers to the phenomena being studied. This review’s methodology and protocol could serve as a guideline for future researchers. The prioritisation of rural health needs and the inclusion of rurality as a variable in South African healthcare policy and strategy is essential in health development research.
- Full Text:
- Date Issued: 2019
Effect of a web-based visual skills training programme on the visual performance of rugby players
- van Rensburg, Justine Jansen
- Authors: van Rensburg, Justine Jansen
- Date: 2019
- Subjects: Rugby football -- South Africa -- Physiological aspects , Physical education and training Performance Sports -- Physiological aspects
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10948/42273 , vital:36641
- Description: With ever increasing important expectations being placed on professional sportsmen and women and, with the main emphasis on winning at all costs, the role of how vision can contribute to sports performance has been under the spotlight in the last few decades. While sport vision programmes can potentially play a vital role in improving sports performance, the efficacy of visual skills training on performance, however, has not been convincingly demonstrated and therefore is still debatable. The primary aim of this study was to investigate the effectiveness of a web-based visual skills training programme on the visual skills performance of NMU Varsity Cup rugby players. The specific visual skills included accommodation, saccadic eye movement, reaction time and peripheral awareness. The study was quasi-experimental in nature and utilized a quantitative approach. A total number of 23 participants that met the inclusion criteria were included in the study by means of purposive sampling. Optometric assessments, on the advice of an optometrist, were conducted to ensure “normal” vision among the participants included in the study. A systematic procedure was employed based on the pre-test to allocate the 23 participants to either a control group (CG) (n=8), an experimental group one (EG1) (n=9) and an experimental group two (EG2) (n=6). The two experimental groups underwent four weeks of visual skills training with the EG1 receiving the web-based visual skills training and EG2 receiving the dynamic visual skills training. The tests used consisted of the Hart Near Far Rock Chart, a Saccadic eye movement chart, simple reaction time and choice reaction time as well as the Batak Pro (Accumulator test). Pre- and post-test scores showed some differences but no statistically significant (p<0.05) differences were found between the three groups for any of the tests conducted. Overall the experimental groups produced larger (non-significant) either pre- to post-test mean differences or post-test results than the control group for six of the seven tests implemented. The findings of this study using a web-based visual skills training programme presented no statistically significant improvements nor better results than the dynamic visual skill training programme in respect of visual skill performance of NMU Varsity rugby players.
- Full Text:
- Date Issued: 2019
- Authors: van Rensburg, Justine Jansen
- Date: 2019
- Subjects: Rugby football -- South Africa -- Physiological aspects , Physical education and training Performance Sports -- Physiological aspects
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10948/42273 , vital:36641
- Description: With ever increasing important expectations being placed on professional sportsmen and women and, with the main emphasis on winning at all costs, the role of how vision can contribute to sports performance has been under the spotlight in the last few decades. While sport vision programmes can potentially play a vital role in improving sports performance, the efficacy of visual skills training on performance, however, has not been convincingly demonstrated and therefore is still debatable. The primary aim of this study was to investigate the effectiveness of a web-based visual skills training programme on the visual skills performance of NMU Varsity Cup rugby players. The specific visual skills included accommodation, saccadic eye movement, reaction time and peripheral awareness. The study was quasi-experimental in nature and utilized a quantitative approach. A total number of 23 participants that met the inclusion criteria were included in the study by means of purposive sampling. Optometric assessments, on the advice of an optometrist, were conducted to ensure “normal” vision among the participants included in the study. A systematic procedure was employed based on the pre-test to allocate the 23 participants to either a control group (CG) (n=8), an experimental group one (EG1) (n=9) and an experimental group two (EG2) (n=6). The two experimental groups underwent four weeks of visual skills training with the EG1 receiving the web-based visual skills training and EG2 receiving the dynamic visual skills training. The tests used consisted of the Hart Near Far Rock Chart, a Saccadic eye movement chart, simple reaction time and choice reaction time as well as the Batak Pro (Accumulator test). Pre- and post-test scores showed some differences but no statistically significant (p<0.05) differences were found between the three groups for any of the tests conducted. Overall the experimental groups produced larger (non-significant) either pre- to post-test mean differences or post-test results than the control group for six of the seven tests implemented. The findings of this study using a web-based visual skills training programme presented no statistically significant improvements nor better results than the dynamic visual skill training programme in respect of visual skill performance of NMU Varsity rugby players.
- Full Text:
- Date Issued: 2019
Mechanisms and modes of β-N-methylamino-lalanine neurotoxicity: the basis for designing therapies
- Authors: Van Onselen, Rianita
- Date: 2019
- Subjects: Cyanobacteria , Amino acids -- Toxicology , Neurotoxic agents
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/32971 , vital:32483
- Description: Since the discovery of the non-canonical amino acid β-N-methylamino-L-alanine (BMAA) and the demonstration of its acute neurotoxicity in chicks and rats, it has been postulated that BMAA might contribute to the development of neurodegenerative diseases worldwide due to its presence in numerous aquatic and terrestrial food webs. This hypothesized link was widely criticized because of the inability to reproduce symptoms in a BMAA-exposed animal model that resembled the symptoms observed in humans, and for the inability to achieve significant levels of toxicity in in vitro models via the postulated mechanisms of toxicity. The most widely described mechanism of BMAA toxicity was excitotoxicity by over-excitation of ionotropic and/or metabotropic glutamate receptors following activation by BMAA. However, the excitotoxic potency of BMAA is much lower than those of other known excitotoxins and it was not known whether BMAA could accumulate in significant concentrations in synapses to cause the said excitotoxicity. Therefore, uptake of BMAA into synaptic vesicles from where it can be released into synapses in high concentrations, was investigated and it was found that, unlike the uptake that was observed for glutamate, BMAA was not taken up into synaptic vesicles. This discovery suggests that BMAA is not released into synapses via synaptic vesicles and that excitotoxicity is an unlikely mechanism of BMAA toxicity in mammalian systems. Misincorporation of BMAA into proteins in the place of L-serine was suggested to be an important mechanism of BMAA toxicity that could lead to protein misfolding and the subsequent protein aggregates that are typically found in the central nervous system (CNS) of neurodegenerative disease patients. However, previous studies in prokaryotes and in a rat pheochromocytoma PC12 cell line showed that misincorporation of BMAA does not occur to any significant extent. However, these studies were criticized for not using human-derived model systems to show that misincorporation does not occur, and it was argued that due to differences in mitochondrial protein synthesis mechanisms, misincorporation of BMAA into human proteins could not be ruled out as a possible mechanism of toxicity. Therefore, misincorporation of BMAA was investigated in a number of human-derived non-neuronal cell lines and directly compared to the misincorporation of other known amino acid analogues. No evidence of misincorporation of BMAA into these cell lines was obtained and therefore it was concluded that misincorporation of BMAA into proteins does not occur in human-derived cell models. Although misincorporation of BMAA into proteins was refuted as a mechanism of toxicity, the strong interactions between BMAA and proteins that require extensive purification procedures to remove the associated BMAA, could not be discounted as a possible contributor to the toxicity of BMAA. Cell-free interactions between BMAA and enzymes, which resulted in reduced activity, were described previously but the nature of these interactions was never determined. Therefore, the direct interactions between BMAA and a range of commercial proteins and melanin (that is known to also have a strong affinity for BMAA) were investigated in an attempt to describe the nature of these interactions. It was discovered that BMAA has a high affinity for hydroxyl groups, and that if these hydroxyl groups in the form of hydroxyl containing amino acid residues occurred in important regulatory or active sites of proteins, BMAA reduced the enzyme activity. Catalase was subsequently selected as an important enzyme required for the maintenance of the delicate reactive oxygen species (ROS) balance in the CNS, to test the effect of BMAA on the activity of the enzyme. BMAA inhibited a human commercial extract of catalase in a cell free system, and this inhibition appeared to be non-competitive in nature. Subsequently, catalase in an extract from a human cell line was also shown to be inhibited by BMAA and it was concluded that this BMAA induced inhibition of catalase could be an important contributor to the toxicity of BMAA in in vivo systems. The affinity of BMAA for hydroxyl groups, especially the reactive L-tyrosine side chain hydroxyl, was recognized as a possible mechanism that can be utilized to protect against the toxicity of BMAA. It was subsequently shown that excess concentrations of L-serine and L-tyrosine could protect against the BMAA-induced enzyme inhibition and improper folding of proteins in a cell-free system. By administering an equimolar concentration of either L-phenylalanine (the soluble precursor of L-tyrosine) or L-serine an hour before administration of BMAA in a rat model, the BMAA-induced neurotoxicity was greatly reduced, especially by treatment with L-phenylalanine, which resulted in a decrease of between 60-70% in the observed neuropathologies. It was recognized that the protection offered by L-phenylalanine was greater than would be expected if protection was by virtue of direct hydroxyl binding alone and it was subsequently hypothesized that the conversion of L-phenylalanine to dopamine could have contributed to the observed protection. Subsequently, the possible protection offered by dopamine, administered as L-DOPA, against BMAA neurotoxicity was investigated in the same neonatal rat model and compared to the protection offered by L-tyrosine. It was discovered that dopamine protected against the BMAAinduced neuronal cell losses in the hippocampus, striatum and spinal cord but it was not as efficient as L-tyrosine in protection against the BMAA-induced proteinopathies, suggesting two distinct mechanisms of BMAA toxicity, one of which is a depletion of dopamine, which had not been previously described. Finally, the nature of the BMAA-induced dopamine depletion was investigated by administering BMAA in combination with other dopaminergic modifiers viz. apomorphine (a D1/D2 receptor agonist), a dopamine transporter inhibitor (GBR12783) and reserpine (a vesicular monoamine transporter -VMAT2- inhibitor) to the neonatal rat model in an attempt to describe how BMAA functions as a dopaminergic toxin. Based on these results it was concluded that BMAA inhibits uptake of dopamine into synaptic vesicles by inhibiting VMAT2-mediated uptake of dopamine, which causes neuronal loss in the hippocampus, striatum and substantia nigra pars compacta, and that the BMAA-induced inhibition of catalase contributes significantly to the toxicity of BMAA by causing an accumulation of hydrogen peroxide in the hippocampus, striatum and spinal cord, which results in extensive neuronal damage in these areas. This work was the first to thoroughly investigate the mechanisms that explain the observed pathologies caused by BMAA in an in vivo model, and was the first to suggest that BMAA can reduce the dopamine in the CNS by inhibiting VMAT2-mediated uptake of dopamine into synaptic vesicles, and increase damage by reactive oxygen species by inhibiting catalase. BMAA is therefore a multimechanistic and multimodal.
- Full Text:
- Date Issued: 2019
- Authors: Van Onselen, Rianita
- Date: 2019
- Subjects: Cyanobacteria , Amino acids -- Toxicology , Neurotoxic agents
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/32971 , vital:32483
- Description: Since the discovery of the non-canonical amino acid β-N-methylamino-L-alanine (BMAA) and the demonstration of its acute neurotoxicity in chicks and rats, it has been postulated that BMAA might contribute to the development of neurodegenerative diseases worldwide due to its presence in numerous aquatic and terrestrial food webs. This hypothesized link was widely criticized because of the inability to reproduce symptoms in a BMAA-exposed animal model that resembled the symptoms observed in humans, and for the inability to achieve significant levels of toxicity in in vitro models via the postulated mechanisms of toxicity. The most widely described mechanism of BMAA toxicity was excitotoxicity by over-excitation of ionotropic and/or metabotropic glutamate receptors following activation by BMAA. However, the excitotoxic potency of BMAA is much lower than those of other known excitotoxins and it was not known whether BMAA could accumulate in significant concentrations in synapses to cause the said excitotoxicity. Therefore, uptake of BMAA into synaptic vesicles from where it can be released into synapses in high concentrations, was investigated and it was found that, unlike the uptake that was observed for glutamate, BMAA was not taken up into synaptic vesicles. This discovery suggests that BMAA is not released into synapses via synaptic vesicles and that excitotoxicity is an unlikely mechanism of BMAA toxicity in mammalian systems. Misincorporation of BMAA into proteins in the place of L-serine was suggested to be an important mechanism of BMAA toxicity that could lead to protein misfolding and the subsequent protein aggregates that are typically found in the central nervous system (CNS) of neurodegenerative disease patients. However, previous studies in prokaryotes and in a rat pheochromocytoma PC12 cell line showed that misincorporation of BMAA does not occur to any significant extent. However, these studies were criticized for not using human-derived model systems to show that misincorporation does not occur, and it was argued that due to differences in mitochondrial protein synthesis mechanisms, misincorporation of BMAA into human proteins could not be ruled out as a possible mechanism of toxicity. Therefore, misincorporation of BMAA was investigated in a number of human-derived non-neuronal cell lines and directly compared to the misincorporation of other known amino acid analogues. No evidence of misincorporation of BMAA into these cell lines was obtained and therefore it was concluded that misincorporation of BMAA into proteins does not occur in human-derived cell models. Although misincorporation of BMAA into proteins was refuted as a mechanism of toxicity, the strong interactions between BMAA and proteins that require extensive purification procedures to remove the associated BMAA, could not be discounted as a possible contributor to the toxicity of BMAA. Cell-free interactions between BMAA and enzymes, which resulted in reduced activity, were described previously but the nature of these interactions was never determined. Therefore, the direct interactions between BMAA and a range of commercial proteins and melanin (that is known to also have a strong affinity for BMAA) were investigated in an attempt to describe the nature of these interactions. It was discovered that BMAA has a high affinity for hydroxyl groups, and that if these hydroxyl groups in the form of hydroxyl containing amino acid residues occurred in important regulatory or active sites of proteins, BMAA reduced the enzyme activity. Catalase was subsequently selected as an important enzyme required for the maintenance of the delicate reactive oxygen species (ROS) balance in the CNS, to test the effect of BMAA on the activity of the enzyme. BMAA inhibited a human commercial extract of catalase in a cell free system, and this inhibition appeared to be non-competitive in nature. Subsequently, catalase in an extract from a human cell line was also shown to be inhibited by BMAA and it was concluded that this BMAA induced inhibition of catalase could be an important contributor to the toxicity of BMAA in in vivo systems. The affinity of BMAA for hydroxyl groups, especially the reactive L-tyrosine side chain hydroxyl, was recognized as a possible mechanism that can be utilized to protect against the toxicity of BMAA. It was subsequently shown that excess concentrations of L-serine and L-tyrosine could protect against the BMAA-induced enzyme inhibition and improper folding of proteins in a cell-free system. By administering an equimolar concentration of either L-phenylalanine (the soluble precursor of L-tyrosine) or L-serine an hour before administration of BMAA in a rat model, the BMAA-induced neurotoxicity was greatly reduced, especially by treatment with L-phenylalanine, which resulted in a decrease of between 60-70% in the observed neuropathologies. It was recognized that the protection offered by L-phenylalanine was greater than would be expected if protection was by virtue of direct hydroxyl binding alone and it was subsequently hypothesized that the conversion of L-phenylalanine to dopamine could have contributed to the observed protection. Subsequently, the possible protection offered by dopamine, administered as L-DOPA, against BMAA neurotoxicity was investigated in the same neonatal rat model and compared to the protection offered by L-tyrosine. It was discovered that dopamine protected against the BMAAinduced neuronal cell losses in the hippocampus, striatum and spinal cord but it was not as efficient as L-tyrosine in protection against the BMAA-induced proteinopathies, suggesting two distinct mechanisms of BMAA toxicity, one of which is a depletion of dopamine, which had not been previously described. Finally, the nature of the BMAA-induced dopamine depletion was investigated by administering BMAA in combination with other dopaminergic modifiers viz. apomorphine (a D1/D2 receptor agonist), a dopamine transporter inhibitor (GBR12783) and reserpine (a vesicular monoamine transporter -VMAT2- inhibitor) to the neonatal rat model in an attempt to describe how BMAA functions as a dopaminergic toxin. Based on these results it was concluded that BMAA inhibits uptake of dopamine into synaptic vesicles by inhibiting VMAT2-mediated uptake of dopamine, which causes neuronal loss in the hippocampus, striatum and substantia nigra pars compacta, and that the BMAA-induced inhibition of catalase contributes significantly to the toxicity of BMAA by causing an accumulation of hydrogen peroxide in the hippocampus, striatum and spinal cord, which results in extensive neuronal damage in these areas. This work was the first to thoroughly investigate the mechanisms that explain the observed pathologies caused by BMAA in an in vivo model, and was the first to suggest that BMAA can reduce the dopamine in the CNS by inhibiting VMAT2-mediated uptake of dopamine into synaptic vesicles, and increase damage by reactive oxygen species by inhibiting catalase. BMAA is therefore a multimechanistic and multimodal.
- Full Text:
- Date Issued: 2019
A comparison of different strategies to control pests and diseases in Brassica spp. production in the Western Cape
- Van Niekerk, Abraham Johannes
- Authors: Van Niekerk, Abraham Johannes
- Date: 2019
- Subjects: Pesticides , Pests -- Control Agricultural pests , Plant diseases
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: http://hdl.handle.net/10948/44122 , vital:37113
- Description: Brassica spp. are cultivated all over the world, commercial species include: cabbage, broccoli, kale, kohlrabi and turnip. In this study the focus was on broccoli (Brassica oleracea) production in the Western Cape province of South Africa and its economically important pests and diseases: sugar beet cyst nematode (Heterodera schachtii), diamondback moth (Plutella xylostella), white blister (Albugo candida) and clubroot (Plasmodiophora brassicae), and the different methods to control these pests and diseases. The control methods focused on in this study included a commercial chemical control programme, a biological control programme and a holistic approach. Other factors were bio-fumigation and chemical fumigation and different crop rotation practices including rotation crops versus no rotation crops. The experimental design was a strip split plot design, with different pest and disease management strategies as the main plot treatment and fumigation and rotation treatment combinations arranged in strips across the main plot treatments. The main plot design was a randomized complete block with four programmes (Control, Holistic, Chemical and Biological) replicated four times and laid out in a Randomised Complete Block Design (RCBD). The treatment design of the strip plot factors was a 2x2 factorial with two fumigations (fumigated chemically and fumigated biologically) and two rotations (crop rotated and monoculture) randomly allocated across main plot treatments. Each experimental unit consisted of 40 plants. Plants were evaluated weekly for the incidence of white blister and diamondback moth. Incidences of clubroot and white blister infection of heads of broccoli were recorded 78 days after planting. Baseline soil samples were analysed to establish the soil chemical properties. Post-trial soil samples were also analysed to investigate the effect of the different practices and programmes on the soil chemical properties. Nematodes were extracted pre-trial and post-trial, and the effect of fumigation and crop rotation on plant parasitic nematodes and the nematode population diversity investigated. In the post-trial soil chemical analysis, a significantly higher concentration of Na was recorded for the biological programme when crop rotation was included compared to the no rotation treatment. The concentration of K was also significantly higher in the no rotation compared to the rotation treatment. The nematode results showed very high numbers of bacterial feeders in all the samples. Overall nematode diversity was lacking and showed very few fungal feeders, omnivores and predators. The nematode indices for all of the samples showed that nematodes were highly enriched and unstructured. Of the plant parasitic nematodes, only Heterodera spp. were obtained in the pre-trial analysis, and incidences of these nematodes were lower at the end of the trial. Low numbers of other plant parasitic nematodes viz. Pratylenchus, Paratrichodorus and Tylenchorhynchus were reported for the post-trial analysis of the soil. Because of the low numbers of plant parasitic nematodes, it was not possible to analyse the data statistically. With regard to diamondback moth and the fungal diseases, crop rotation and fumigation did not significantly affect the incidence of white blister and diamondback moth. A significant “days after planting by control programme” interaction was reported for the incidence of white blister on foliage and the incidence of diamondback moth. All three control programmes significantly reduced the incidence of diamondback moth with the chemical programme being significantly more effective than the other two programmes. All three programmes also significantly reduced the incidence of white blister on foliage and the holistic and biological programmes significantly reduced the incidence of white blister on broccoli heads with the holistic programme being significantly more effective than the biological programme. There was no clubroot infection in the trial for any of the treatments. Results of this study showed that it is possible to manage diseases and pests of broccoli using a holistic approach. However, long term trials are needed to confirm the results obtained in this study.
- Full Text:
- Date Issued: 2019
- Authors: Van Niekerk, Abraham Johannes
- Date: 2019
- Subjects: Pesticides , Pests -- Control Agricultural pests , Plant diseases
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: http://hdl.handle.net/10948/44122 , vital:37113
- Description: Brassica spp. are cultivated all over the world, commercial species include: cabbage, broccoli, kale, kohlrabi and turnip. In this study the focus was on broccoli (Brassica oleracea) production in the Western Cape province of South Africa and its economically important pests and diseases: sugar beet cyst nematode (Heterodera schachtii), diamondback moth (Plutella xylostella), white blister (Albugo candida) and clubroot (Plasmodiophora brassicae), and the different methods to control these pests and diseases. The control methods focused on in this study included a commercial chemical control programme, a biological control programme and a holistic approach. Other factors were bio-fumigation and chemical fumigation and different crop rotation practices including rotation crops versus no rotation crops. The experimental design was a strip split plot design, with different pest and disease management strategies as the main plot treatment and fumigation and rotation treatment combinations arranged in strips across the main plot treatments. The main plot design was a randomized complete block with four programmes (Control, Holistic, Chemical and Biological) replicated four times and laid out in a Randomised Complete Block Design (RCBD). The treatment design of the strip plot factors was a 2x2 factorial with two fumigations (fumigated chemically and fumigated biologically) and two rotations (crop rotated and monoculture) randomly allocated across main plot treatments. Each experimental unit consisted of 40 plants. Plants were evaluated weekly for the incidence of white blister and diamondback moth. Incidences of clubroot and white blister infection of heads of broccoli were recorded 78 days after planting. Baseline soil samples were analysed to establish the soil chemical properties. Post-trial soil samples were also analysed to investigate the effect of the different practices and programmes on the soil chemical properties. Nematodes were extracted pre-trial and post-trial, and the effect of fumigation and crop rotation on plant parasitic nematodes and the nematode population diversity investigated. In the post-trial soil chemical analysis, a significantly higher concentration of Na was recorded for the biological programme when crop rotation was included compared to the no rotation treatment. The concentration of K was also significantly higher in the no rotation compared to the rotation treatment. The nematode results showed very high numbers of bacterial feeders in all the samples. Overall nematode diversity was lacking and showed very few fungal feeders, omnivores and predators. The nematode indices for all of the samples showed that nematodes were highly enriched and unstructured. Of the plant parasitic nematodes, only Heterodera spp. were obtained in the pre-trial analysis, and incidences of these nematodes were lower at the end of the trial. Low numbers of other plant parasitic nematodes viz. Pratylenchus, Paratrichodorus and Tylenchorhynchus were reported for the post-trial analysis of the soil. Because of the low numbers of plant parasitic nematodes, it was not possible to analyse the data statistically. With regard to diamondback moth and the fungal diseases, crop rotation and fumigation did not significantly affect the incidence of white blister and diamondback moth. A significant “days after planting by control programme” interaction was reported for the incidence of white blister on foliage and the incidence of diamondback moth. All three control programmes significantly reduced the incidence of diamondback moth with the chemical programme being significantly more effective than the other two programmes. All three programmes also significantly reduced the incidence of white blister on foliage and the holistic and biological programmes significantly reduced the incidence of white blister on broccoli heads with the holistic programme being significantly more effective than the biological programme. There was no clubroot infection in the trial for any of the treatments. Results of this study showed that it is possible to manage diseases and pests of broccoli using a holistic approach. However, long term trials are needed to confirm the results obtained in this study.
- Full Text:
- Date Issued: 2019
Isolation and characterisation of a channel inhibitor from Bunodosoma capense
- Authors: Van Losenoord, Wynand
- Date: 2019
- Subjects: Bioactive compounds , Potassium channels Medical microbiology
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/44134 , vital:37114
- Description: Voltage gated ion channels have recently become a subject of investigation as possible pharmaceutical targets. Research has linked the activity of ion channels directly to antiinflammatory pathways, energy homeostasis, cancer proliferation and painful diabetic neuropathy. Sea anemones secrete a diverse array of bioactive compounds including potassium and sodium channel inhibitors. A novel sodium channel inhibitor (molecular mass of 4619.7 ± 0.6 Da) with a predicted sequence: CLCNSDGPSV RGNTLSGILW LAGCPSGWHN CKKHKPTIGW CCK was isolated from Bunodosoma capense using a modified stimulation technique to induce the secretion of the neurotoxin rich mucus confirmed by an Artemia nauplii swimming assay. The peptide purification combined size-exclusion and reverse-phase high performance liquid chromatography. A thallium-based ion flux assay confirmed the presence of a sodium channel inhibitor and purity was determined using a modified tricine SDS-PAGE system. The peptide isolated indicated a tight conformation with the presence of multiple disulfide bonds in a cystine knot conformation. An IC50 value of 26 nM was determined for sodium channel inhibition on MCF-7 cells, indicating increased toxicity in comparison to sodium channel inhibitors previously isolated from Bunodosoma species.
- Full Text:
- Date Issued: 2019
- Authors: Van Losenoord, Wynand
- Date: 2019
- Subjects: Bioactive compounds , Potassium channels Medical microbiology
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/44134 , vital:37114
- Description: Voltage gated ion channels have recently become a subject of investigation as possible pharmaceutical targets. Research has linked the activity of ion channels directly to antiinflammatory pathways, energy homeostasis, cancer proliferation and painful diabetic neuropathy. Sea anemones secrete a diverse array of bioactive compounds including potassium and sodium channel inhibitors. A novel sodium channel inhibitor (molecular mass of 4619.7 ± 0.6 Da) with a predicted sequence: CLCNSDGPSV RGNTLSGILW LAGCPSGWHN CKKHKPTIGW CCK was isolated from Bunodosoma capense using a modified stimulation technique to induce the secretion of the neurotoxin rich mucus confirmed by an Artemia nauplii swimming assay. The peptide purification combined size-exclusion and reverse-phase high performance liquid chromatography. A thallium-based ion flux assay confirmed the presence of a sodium channel inhibitor and purity was determined using a modified tricine SDS-PAGE system. The peptide isolated indicated a tight conformation with the presence of multiple disulfide bonds in a cystine knot conformation. An IC50 value of 26 nM was determined for sodium channel inhibition on MCF-7 cells, indicating increased toxicity in comparison to sodium channel inhibitors previously isolated from Bunodosoma species.
- Full Text:
- Date Issued: 2019
Purification and biochemical characterisation of a putative sodium channel agonist secreted from the South African Knobbly sea anemone Bunodosoma capense
- van Losenoord, Wynand, Krause, Jason, Parker-Nance, Shirley, Krause, Rui W M, Stoychey, Stoyan, Frost, Carminita L
- Authors: van Losenoord, Wynand , Krause, Jason , Parker-Nance, Shirley , Krause, Rui W M , Stoychey, Stoyan , Frost, Carminita L
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/194082 , vital:45421 , xlink:href="https://doi.org/10.1016/j.toxicon.2019.06.222"
- Description: Voltage gated ion channels have become a subject of investigation as possible pharmaceutical targets. Research has linked the activity of ion channels directly to anti-inflammatory pathways, energy homeostasis, cancer proliferation and painful diabetic neuropathy. Sea anemones secrete a diverse array of bioactive compounds including potassium and sodium channel toxins. A putative novel sodium channel agonist (molecular mass of 4619.7 Da) with a predicted sequence: CLCNSDGPSV RGNTLSGILW LAGCPSGWHN CKKHKPTIGW CCK was isolated from Bunodosoma capense using a modified stimulation technique to induce the secretion of the neurotoxin rich mucus confirmed by an Artemia nauplii bio-assay. The peptide purification combined size-exclusion and reverse-phase high performance liquid chromatography. A thallium-based ion flux assay confirmed the presence of a sodium channel agonist/inhibitor and purity was determined using a modified tricine SDS-PAGE system. The peptide isolated indicated the presence of multiple disulfide bonds in a tight β-defensin cystine conformation. An IC50 value of 26 nM was determined for total channel inhibition on MCF-7 cells. The unique putative sodium channel agonist initiating with a cystine bond indicates a divergent evolution to those previously isolated from Bunodosoma species.
- Full Text:
- Date Issued: 2019
- Authors: van Losenoord, Wynand , Krause, Jason , Parker-Nance, Shirley , Krause, Rui W M , Stoychey, Stoyan , Frost, Carminita L
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/194082 , vital:45421 , xlink:href="https://doi.org/10.1016/j.toxicon.2019.06.222"
- Description: Voltage gated ion channels have become a subject of investigation as possible pharmaceutical targets. Research has linked the activity of ion channels directly to anti-inflammatory pathways, energy homeostasis, cancer proliferation and painful diabetic neuropathy. Sea anemones secrete a diverse array of bioactive compounds including potassium and sodium channel toxins. A putative novel sodium channel agonist (molecular mass of 4619.7 Da) with a predicted sequence: CLCNSDGPSV RGNTLSGILW LAGCPSGWHN CKKHKPTIGW CCK was isolated from Bunodosoma capense using a modified stimulation technique to induce the secretion of the neurotoxin rich mucus confirmed by an Artemia nauplii bio-assay. The peptide purification combined size-exclusion and reverse-phase high performance liquid chromatography. A thallium-based ion flux assay confirmed the presence of a sodium channel agonist/inhibitor and purity was determined using a modified tricine SDS-PAGE system. The peptide isolated indicated the presence of multiple disulfide bonds in a tight β-defensin cystine conformation. An IC50 value of 26 nM was determined for total channel inhibition on MCF-7 cells. The unique putative sodium channel agonist initiating with a cystine bond indicates a divergent evolution to those previously isolated from Bunodosoma species.
- Full Text:
- Date Issued: 2019
Perceptions on the efficacy of equine assisted play therapy™ in addressing low self-esteem of young bullied children
- Authors: Van Loggerenberg, Monique
- Date: 2019
- Subjects: Animals -- Therapeutic use , Play therapy Bullying Self-esteem -- South Africa Educational psychology -- South Africa
- Language: English
- Type: Thesis , Doctoral , DEd
- Identifier: http://hdl.handle.net/10948/44179 , vital:37126
- Description: During the past decade, a surge of research emerged regarding the human-animal bond and how interactions with animals could be beneficial to both humans and animals on emotional, cognitive and biological levels. However, amongst others, a gap in literature on the experiences and perceptions of participants involved in animal assisted therapy programmes remain. This research focused on a specific population (bully victims presenting with low self-esteem in the middle childhood phase), also reflecting the perceptions of parties not directly involved in therapy, such as parents and teachers. This research adhered to strict ethical standards in accordance to NMU’s Ethical guidelines as well as in accordance to guidelines provided by the International Institute of Animal Assisted Play Therapy™. The welfare of both the horse and humans involved in this study was deemed equally important. Based upon the Gestalt therapy theory, the therapees were given the opportunity to explore alternatives, be creative and reveal specific therapeutic elements needing attention during each session. The focus was on building a therapeutic relationship in which the therapees could trust themselves, the therapist and horse to find the answers they needed and obtain the necessary skills to overcome feelings of helplessness when being bullied. Therapees presenting with low self-esteem results in specific vulnerability as it can be both the cause of being bullied or lead to being bullied. During the Equine Assisted Play Therapy™ (EAPT™) sessions the disempowered victim was allowed the opportunity to succeed in being assertive. Such children in therapy were given the opportunity to take centre-stage without being made fun of, whilst being encouraged to try out new behaviour and experience personal change. This study highlighted the perceptions of parents and teachers and the lived experiences of bully-victims. Exploring the efficacy of a relatively new therapeutic method, EAPT™ in addressing the low self-esteem levels and subsequent behaviour in the children who participated in this form of therapy, showed promising results in increasing self-esteem levels and positive behavioural changes in therapees.
- Full Text:
- Date Issued: 2019
- Authors: Van Loggerenberg, Monique
- Date: 2019
- Subjects: Animals -- Therapeutic use , Play therapy Bullying Self-esteem -- South Africa Educational psychology -- South Africa
- Language: English
- Type: Thesis , Doctoral , DEd
- Identifier: http://hdl.handle.net/10948/44179 , vital:37126
- Description: During the past decade, a surge of research emerged regarding the human-animal bond and how interactions with animals could be beneficial to both humans and animals on emotional, cognitive and biological levels. However, amongst others, a gap in literature on the experiences and perceptions of participants involved in animal assisted therapy programmes remain. This research focused on a specific population (bully victims presenting with low self-esteem in the middle childhood phase), also reflecting the perceptions of parties not directly involved in therapy, such as parents and teachers. This research adhered to strict ethical standards in accordance to NMU’s Ethical guidelines as well as in accordance to guidelines provided by the International Institute of Animal Assisted Play Therapy™. The welfare of both the horse and humans involved in this study was deemed equally important. Based upon the Gestalt therapy theory, the therapees were given the opportunity to explore alternatives, be creative and reveal specific therapeutic elements needing attention during each session. The focus was on building a therapeutic relationship in which the therapees could trust themselves, the therapist and horse to find the answers they needed and obtain the necessary skills to overcome feelings of helplessness when being bullied. Therapees presenting with low self-esteem results in specific vulnerability as it can be both the cause of being bullied or lead to being bullied. During the Equine Assisted Play Therapy™ (EAPT™) sessions the disempowered victim was allowed the opportunity to succeed in being assertive. Such children in therapy were given the opportunity to take centre-stage without being made fun of, whilst being encouraged to try out new behaviour and experience personal change. This study highlighted the perceptions of parents and teachers and the lived experiences of bully-victims. Exploring the efficacy of a relatively new therapeutic method, EAPT™ in addressing the low self-esteem levels and subsequent behaviour in the children who participated in this form of therapy, showed promising results in increasing self-esteem levels and positive behavioural changes in therapees.
- Full Text:
- Date Issued: 2019
The relationship between psychological capital and work engagement among educators in Port Elizabeth
- Authors: Van Kerkhof, Michelle
- Date: 2019
- Subjects: Human capital -- Psychological aspects , Psychology, Industrial Employees -- Psychology Management|xPsychological aspects
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10948/44145 , vital:37117
- Description: Psychological Capital (PsyCap) and work engagement (WE) are both positive constructs which research shows has an advantageous effect on the performance of the organisation. The educational system, and in particular the job of the educator, remains an important field of study as 80% of schools in South Africa are deemed dysfunctional (Spaull, 2013). Although educators face numerous challenges, there are still educators who remain determined in their work role. This research used a cross-sectional design, using a composite questionnaire to measure PsyCap and WE. The self-report questionnaires were distributed to a sample of educators (n=106) of which 53% were from private schools and 47% were from public schools in Port Elizabeth. Various studies both locally and abroad confirm the reliability and validity of the PCQ-24 and UWES-9 measures utilised in this study. The present study aimed to determine the relationship between PsyCap and WE of educators. The relationship between PsyCap and WE was assessed using Pearson correlation and multiple regression analysis. Furthermore, it also considered whether a significant distinction exists among the PsyCap and WE levels of private and public schools in Port Elizabeth. A t-test was used to establish the difference among the levels of PsyCap and WE of private and public school teachers. As indicated by previous research, the current study uncovered that PsyCap predicts WE, exhibiting a positive relationship among the constructs. In addition, this study found that there was a difference among the PsyCap and WE levels of private and public school teachers in Port Elizabeth.
- Full Text:
- Date Issued: 2019
The relationship between psychological capital and work engagement among educators in Port Elizabeth
- Authors: Van Kerkhof, Michelle
- Date: 2019
- Subjects: Human capital -- Psychological aspects , Psychology, Industrial Employees -- Psychology Management|xPsychological aspects
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10948/44145 , vital:37117
- Description: Psychological Capital (PsyCap) and work engagement (WE) are both positive constructs which research shows has an advantageous effect on the performance of the organisation. The educational system, and in particular the job of the educator, remains an important field of study as 80% of schools in South Africa are deemed dysfunctional (Spaull, 2013). Although educators face numerous challenges, there are still educators who remain determined in their work role. This research used a cross-sectional design, using a composite questionnaire to measure PsyCap and WE. The self-report questionnaires were distributed to a sample of educators (n=106) of which 53% were from private schools and 47% were from public schools in Port Elizabeth. Various studies both locally and abroad confirm the reliability and validity of the PCQ-24 and UWES-9 measures utilised in this study. The present study aimed to determine the relationship between PsyCap and WE of educators. The relationship between PsyCap and WE was assessed using Pearson correlation and multiple regression analysis. Furthermore, it also considered whether a significant distinction exists among the PsyCap and WE levels of private and public schools in Port Elizabeth. A t-test was used to establish the difference among the levels of PsyCap and WE of private and public school teachers. As indicated by previous research, the current study uncovered that PsyCap predicts WE, exhibiting a positive relationship among the constructs. In addition, this study found that there was a difference among the PsyCap and WE levels of private and public school teachers in Port Elizabeth.
- Full Text:
- Date Issued: 2019
Students’ experiences and perceptions of racial prejudice and discrimination on social networking sites
- Authors: Van Graan, Christelle
- Date: 2019
- Subjects: Online social networks--Psychological aspects , Internet users -- Psychology Cyberspace -- Psychological aspects Racism -- Psychological aspects Social psychology
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10948/44158 , vital:37119
- Description: The present study set out to enhance the understanding of racial prejudice and discrimination on social networking websites or ‘sites’ from the perspective of university students. The research focused on discovering the perceived determinant factors of online racial prejudice and discrimination, as well as the impact social networking sites have on such behaviour. A qualitative research design was selected, which utilised the grounded theory method to explore and describe the experiences and perceptions of the eight participants recruited by means of purposive sampling. The aim of the study was achieved through individual semi-structured interviews and a concept definition questionnaire as data collection tools. The findings were compared to major extant theories and literature to determine whether existing explanations for the occurrence of this online behaviour is sufficient to account for this phenomenon. Using an iterative process of thematic analysis, the findings revealed several perceived factors that contribute to this behaviour. It was found that social networking site users, in all their psychological, psychosocial and cognitive attributes, are the primary source for this behaviour. Moreover, online racial prejudice and discrimination is initiated by the use of these platforms and their facilitative features, which has a perceived negative impact on social and racial relations. Grounded in the research data, an explanatory theory was formulated of individuals’ perceived behaviour on social networking sites, specifically pertaining to racial prejudice and discrimination, as well as to how this negatively manifests and causes racial division in society.
- Full Text:
- Date Issued: 2019
- Authors: Van Graan, Christelle
- Date: 2019
- Subjects: Online social networks--Psychological aspects , Internet users -- Psychology Cyberspace -- Psychological aspects Racism -- Psychological aspects Social psychology
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10948/44158 , vital:37119
- Description: The present study set out to enhance the understanding of racial prejudice and discrimination on social networking websites or ‘sites’ from the perspective of university students. The research focused on discovering the perceived determinant factors of online racial prejudice and discrimination, as well as the impact social networking sites have on such behaviour. A qualitative research design was selected, which utilised the grounded theory method to explore and describe the experiences and perceptions of the eight participants recruited by means of purposive sampling. The aim of the study was achieved through individual semi-structured interviews and a concept definition questionnaire as data collection tools. The findings were compared to major extant theories and literature to determine whether existing explanations for the occurrence of this online behaviour is sufficient to account for this phenomenon. Using an iterative process of thematic analysis, the findings revealed several perceived factors that contribute to this behaviour. It was found that social networking site users, in all their psychological, psychosocial and cognitive attributes, are the primary source for this behaviour. Moreover, online racial prejudice and discrimination is initiated by the use of these platforms and their facilitative features, which has a perceived negative impact on social and racial relations. Grounded in the research data, an explanatory theory was formulated of individuals’ perceived behaviour on social networking sites, specifically pertaining to racial prejudice and discrimination, as well as to how this negatively manifests and causes racial division in society.
- Full Text:
- Date Issued: 2019
The hypolithic invertebrate community in the eastern Karoo: the role of rock size, microclimate and recolonization
- Authors: Van der Westhuizen, Tara
- Date: 2019
- Subjects: Habitat (Ecology) -- South Africa -- Karoo , Biotic communities -- South Africa -- Karoo Invertebrates Ecosystem management -- South Africa -- Karoo Soil microbial ecology
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/44191 , vital:37128
- Description: Hypolithic habitats are important for the persistence of fauna that utilize these habitats as refuges and resource patches. Little is known, however, about the composition and structure of this community in the semi-arid Karoo. The current study therefore aims to explore the patterns and processes behind hypolithic communities, through determining the effect of rock size and baboon presence on the hypolithic community, the influence of rock size on the microclimate experienced under rocks, as well as determining the short- (over five days) and long- (over 12 months) term colonisation of the hypolithic habitat following a rock rolling disturbance, in a semi-arid Karoo environment. The hypolithic fauna encountered, and the temperature and moisture content experienced under a range of rock sizes were measured. Additionally, hypolithic fauna under rocks that were rolled to mimic rock rolling by baboons were sampled after a set period (i.e. over five days and 12 months). Large rocks were found to provide a more stable microclimate than small rocks. The probability of hypolithic fauna presence was influenced by rock size and season, and hypolithic fauna abundance (except in the dry season), richness, body size and biomass did not correlate with rock size. Additionally, the probability of detecting hypolithic fauna under intermediate sized and larger rocks was greater in the presence of baboons than in the absence of baboons, and in the presence of baboons hypolithic fauna richness increased with rock size. Furthermore, it was shown that hypolithic fauna abundance and biomass did not differ under rolled rocks over a short- (i.e. over five days) or long- (i.e. over 12 months) term period. The short-term colonisation of hypolithic habitats was not influenced by season or rock density. Lastly, most of the change in hypolithic community composition (over 12 months) occurred in the first three months and thereafter the hypolithic community composition approached pre-disturbance levels in month 12. The hypolithic habitat was shown to be influenced by a variety of conditions and processes affecting hypolithic community composition and structure. This study therefore contributes to our understanding of the hypolithic invertebrate community in the eastern Karoo, and the influence of rock size, baboon presence, microclimate and colonisation on hypolithic community composition and structure.
- Full Text:
- Date Issued: 2019
- Authors: Van der Westhuizen, Tara
- Date: 2019
- Subjects: Habitat (Ecology) -- South Africa -- Karoo , Biotic communities -- South Africa -- Karoo Invertebrates Ecosystem management -- South Africa -- Karoo Soil microbial ecology
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/44191 , vital:37128
- Description: Hypolithic habitats are important for the persistence of fauna that utilize these habitats as refuges and resource patches. Little is known, however, about the composition and structure of this community in the semi-arid Karoo. The current study therefore aims to explore the patterns and processes behind hypolithic communities, through determining the effect of rock size and baboon presence on the hypolithic community, the influence of rock size on the microclimate experienced under rocks, as well as determining the short- (over five days) and long- (over 12 months) term colonisation of the hypolithic habitat following a rock rolling disturbance, in a semi-arid Karoo environment. The hypolithic fauna encountered, and the temperature and moisture content experienced under a range of rock sizes were measured. Additionally, hypolithic fauna under rocks that were rolled to mimic rock rolling by baboons were sampled after a set period (i.e. over five days and 12 months). Large rocks were found to provide a more stable microclimate than small rocks. The probability of hypolithic fauna presence was influenced by rock size and season, and hypolithic fauna abundance (except in the dry season), richness, body size and biomass did not correlate with rock size. Additionally, the probability of detecting hypolithic fauna under intermediate sized and larger rocks was greater in the presence of baboons than in the absence of baboons, and in the presence of baboons hypolithic fauna richness increased with rock size. Furthermore, it was shown that hypolithic fauna abundance and biomass did not differ under rolled rocks over a short- (i.e. over five days) or long- (i.e. over 12 months) term period. The short-term colonisation of hypolithic habitats was not influenced by season or rock density. Lastly, most of the change in hypolithic community composition (over 12 months) occurred in the first three months and thereafter the hypolithic community composition approached pre-disturbance levels in month 12. The hypolithic habitat was shown to be influenced by a variety of conditions and processes affecting hypolithic community composition and structure. This study therefore contributes to our understanding of the hypolithic invertebrate community in the eastern Karoo, and the influence of rock size, baboon presence, microclimate and colonisation on hypolithic community composition and structure.
- Full Text:
- Date Issued: 2019
Intercountry adoption and alternative care in South Africa: a model for determining placement in the best interests of the child
- Authors: Van der Walt, Glynis Trow
- Date: 2019
- Subjects: Intercountry adoption -- South Africa , ntercountry adoption -- Law and legislation Interethnic adoption -- South Africa Interracial adoption -- South Africa Children (International law) Children -- Legal status, laws, etc
- Language: English
- Type: Thesis , Doctoral , LLD
- Identifier: http://hdl.handle.net/10948/44202 , vital:37129
- Description: The concept that the family forms the foundation of our society is well established in national and international law.1 The family unit provides a child with a sense of security and identity.2 Moreover, the family as a unit plays a pivotal role in the upbringing of children, enabling them to develop to their full potential.3 Children who have inadequate or no parental care are clearly at risk of being denied such a nurturing environment. The large number of orphaned children following the devastating effects of World War II highlighted the serious need for countries to consider appropriate alternative placement for such children.5 Recognising the importance of the family unit, the Universal Declaration of Human Rights (UDHR) expressly acknowledges the family as the “natural and fundamental group unit of society”.6 Article 16 of the UDHR further states that the family unit is entitled to protection by the state and society.7 However, the vulnerability of parents, families and children has been intensified by recent global, regional and national developments, including the global economic crisis, devastating consequences of the HIV/AIDS pandemic, widespread poverty,8 unwanted pregnancies,9 child abandonment,10 rapid urbanisation, and the increased migration of adults and children into and within South Africa in search of economic and political refuge.11 In particular, the impact of the HIV pandemic on children in South Africa cannot be understated. South Africa has the largest percentage of HIV/AIDS-infected persons in the world, resulting in many children in South Africa being deprived of a family environment. The importance of family and the role it must play in caring for a child cannot be doubted, and both the national law of South Africa and international law bear testimony to this. Accordingly, it is understandable that the biological family remains the primary favoured unit of care for a child. Where, for whatever reason, the natural family fails or is unavailable to care for the child concerned, national and international law make provision for the care of an orphaned and/or abandoned child (OAC). Family forms are changing around the world, and South Africa is typical in several respects. Diverse family arrangements and household forms are recognised as providing a family-type environment for a South African child. In understanding the meaning of “family” in South Africa it must be noted that the family may extend beyond the biological parents of a child to a multi-generational network of people who are linked by blood, including grandparents, aunts, uncles and cousins. Relationship can also include non-blood relationships as in the instance of relationship through the ties of marriage or ties of co-residence. Whilst not exclusive to South Africa, it must also be noted in South Africa under apartheid regime, policies and practices were designed specifically to protect the nuclear family. The Department of Social Development (DSD) drafted the White Paper on Families and this was approved in 2013. The White Paper made conscious strides in granting recognition to a diversity of family forms in South Africa. It departed from the assumptions held of Western or nuclear families only as a norm. It is in light of this diversity that the concept “family” must be read in this research. Consideration of placing a child in appropriate alternative care must be contemplated in light of the context of the human rights movement and the development and recognition of the rights of a child in his or her own right.
- Full Text:
- Date Issued: 2019
- Authors: Van der Walt, Glynis Trow
- Date: 2019
- Subjects: Intercountry adoption -- South Africa , ntercountry adoption -- Law and legislation Interethnic adoption -- South Africa Interracial adoption -- South Africa Children (International law) Children -- Legal status, laws, etc
- Language: English
- Type: Thesis , Doctoral , LLD
- Identifier: http://hdl.handle.net/10948/44202 , vital:37129
- Description: The concept that the family forms the foundation of our society is well established in national and international law.1 The family unit provides a child with a sense of security and identity.2 Moreover, the family as a unit plays a pivotal role in the upbringing of children, enabling them to develop to their full potential.3 Children who have inadequate or no parental care are clearly at risk of being denied such a nurturing environment. The large number of orphaned children following the devastating effects of World War II highlighted the serious need for countries to consider appropriate alternative placement for such children.5 Recognising the importance of the family unit, the Universal Declaration of Human Rights (UDHR) expressly acknowledges the family as the “natural and fundamental group unit of society”.6 Article 16 of the UDHR further states that the family unit is entitled to protection by the state and society.7 However, the vulnerability of parents, families and children has been intensified by recent global, regional and national developments, including the global economic crisis, devastating consequences of the HIV/AIDS pandemic, widespread poverty,8 unwanted pregnancies,9 child abandonment,10 rapid urbanisation, and the increased migration of adults and children into and within South Africa in search of economic and political refuge.11 In particular, the impact of the HIV pandemic on children in South Africa cannot be understated. South Africa has the largest percentage of HIV/AIDS-infected persons in the world, resulting in many children in South Africa being deprived of a family environment. The importance of family and the role it must play in caring for a child cannot be doubted, and both the national law of South Africa and international law bear testimony to this. Accordingly, it is understandable that the biological family remains the primary favoured unit of care for a child. Where, for whatever reason, the natural family fails or is unavailable to care for the child concerned, national and international law make provision for the care of an orphaned and/or abandoned child (OAC). Family forms are changing around the world, and South Africa is typical in several respects. Diverse family arrangements and household forms are recognised as providing a family-type environment for a South African child. In understanding the meaning of “family” in South Africa it must be noted that the family may extend beyond the biological parents of a child to a multi-generational network of people who are linked by blood, including grandparents, aunts, uncles and cousins. Relationship can also include non-blood relationships as in the instance of relationship through the ties of marriage or ties of co-residence. Whilst not exclusive to South Africa, it must also be noted in South Africa under apartheid regime, policies and practices were designed specifically to protect the nuclear family. The Department of Social Development (DSD) drafted the White Paper on Families and this was approved in 2013. The White Paper made conscious strides in granting recognition to a diversity of family forms in South Africa. It departed from the assumptions held of Western or nuclear families only as a norm. It is in light of this diversity that the concept “family” must be read in this research. Consideration of placing a child in appropriate alternative care must be contemplated in light of the context of the human rights movement and the development and recognition of the rights of a child in his or her own right.
- Full Text:
- Date Issued: 2019
The influence of multinational corporations in promoting foreign direct investment in the South African business environment
- Van der Berg, Jan Gabriel Mara
- Authors: Van der Berg, Jan Gabriel Mara
- Date: 2019
- Subjects: Investments, Foreign -- South Africa , Business enterprises Business Organisations Industrial promotion
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/44213 , vital:37131
- Description: One of the major driving forces behind international trade over the past thirty years has been Foreign Direct Investment (FDI). Due to the importance of FDI, a vast amount of research has been conducted on the various elements that make up FDI. There has also been widespread research done to measure the impact of FDI on host countries, and attempts have been made to determine the long-term benefits thereof. Despite the existent research on FDI, there is a dearth of literature on the unique situation in South Africa (due to the country’s fragmented past) and the impact of FDI on the South African economy. This study attempts to address this research gap and to add to the existent body of knowledge on FDI market entry. Thus, the primary objective of this study was to examine the impact of multinational corporations (MNCs) in promoting the entry of FDIs in South Africa, and the effectiveness of these investments in the South African business environment. The comprehensive literature review in this study included a discussion of the background to the pre- and post-apartheid South African economy, and the various efforts made by the South African government to facilitate sustainable economic growth through various economic policies. FDI was identified as one of the four major indicators of economic growth and was therefore investigated as a concept, strategy and driver of change. The South African marketing environment was analysed in order to assist in the identification of variables that are conducive to FDI. The final section of the literature review utilised three cases to better illustrate and understand the different challenges, market entry strategies and long-term implications of FDI. In this study, the independent variables (international marketing environment, stakeholder intervention, government considerations, resources and FDI incentives) were identified as influencing the mediating variable (FDI market entry strategy) and the dependent variables (competitiveness, sustainability, trade agreements and commitment of traders). These independent variables were selected to construct a hypothesised model and the research hypotheses. To this end, an empirical investigation was conducted, the measuring instrument used in this investigation was a questionnaire, which was assembled with the help of insights gained from secondary sources. The study respondents were selected through convenience sampling. A total of 210 respondents participated in the study, and 165 useable questionnaires were subjected to statistical analysis. The data collected for this study was subjected to five phases of analysis: exploratory factor analysis to assess validity; Cronbach’s alpha was used to test for internal consistency reliability; descriptive statistics to describe the fundamental features of the data by providing a statistical summary and analysis; and the nine hypotheses pertaining to the relationships between different variables were assessed using inferential statistical procedures, Pearson’s product correlation and regression analysis. This led to the adaptation of the hypothesised model and the hypotheses so as to indicate the changes resulting from the EFA. The findings of this study reveals that external stakeholder intervention as well as FDI incentives and resources effectively influence FDI market entry strategy in the South African business environment. The study results further reveal that the promotion of FDI market entry strategy positively influences competitiveness, sustainability, trade agreements and commitment of traders in the South African business environment. For MNCs to be successful in the expansion of FDI market entry strategy in the South African business environment, the study recommends that it is important to consider the availability of potential local partners, proximity to trading routes, reduction of the costs involved in supplying the market, the effect of tariff barriers and a competitive domestic economy. It is further recommended that MNCs need to focus on the utilisation of reliable and effective equipment in order to enable the productive management of operations in the South African business environment. The study also recommends the South African business environment as a strategic investment destination for the promotion of FDI market entry strategy as it offers low production costs in particular trading locations. This study has contributed to the field of FDI and the FDI market entry strategies employed by MNCs in South Africa. The research findings identified the international marketing (SLEPTS) factors through an assessment of the South African marketing environment, as these factors are deemed important for FDI to occur. The study also highlights the critical international marketing factors that could be used to improve local conditions through a mixture of incentives and policy re-alignment, so as to be more conducive to attracting large scale FDI. The hypothesised model developed for this study contributed to identifying the influence of external stakeholders on the successful market entry of FDI into South Africa, a critical element that MNCs usually only identify after market entry is complete. Evidence from the study shows that the South African government should direct FDI incentives towards those sectors in the economy that stand to benefit the most from the spill-over effects of FDI, in order to maximise the impact of FDI on the local economy. The research also indicates that elements such as restrictive legislation and government corruption may, to a certain degree, hinder FDI; therefore, these issues need to be addressed through legislation. It is recommended that all local efforts to attract FDI are industry or sector focussed, and that they are guided by government policies towards the greater benefit of the South African economy. Furthermore, the study found that the relationship between the host country and the MNC is critical to achieving sustainability in the long-term; therefore, it is suggested that the South African government improves its relationship with local businesses and MNCs that are looking to invest in South Africa. To conclude, it was found that South Africa has a very important role to play in attracting global FDI to Africa, as it has an accessible market based on geographic location, trade channels and traditional linkages with African and European networks.
- Full Text:
- Date Issued: 2019
- Authors: Van der Berg, Jan Gabriel Mara
- Date: 2019
- Subjects: Investments, Foreign -- South Africa , Business enterprises Business Organisations Industrial promotion
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/44213 , vital:37131
- Description: One of the major driving forces behind international trade over the past thirty years has been Foreign Direct Investment (FDI). Due to the importance of FDI, a vast amount of research has been conducted on the various elements that make up FDI. There has also been widespread research done to measure the impact of FDI on host countries, and attempts have been made to determine the long-term benefits thereof. Despite the existent research on FDI, there is a dearth of literature on the unique situation in South Africa (due to the country’s fragmented past) and the impact of FDI on the South African economy. This study attempts to address this research gap and to add to the existent body of knowledge on FDI market entry. Thus, the primary objective of this study was to examine the impact of multinational corporations (MNCs) in promoting the entry of FDIs in South Africa, and the effectiveness of these investments in the South African business environment. The comprehensive literature review in this study included a discussion of the background to the pre- and post-apartheid South African economy, and the various efforts made by the South African government to facilitate sustainable economic growth through various economic policies. FDI was identified as one of the four major indicators of economic growth and was therefore investigated as a concept, strategy and driver of change. The South African marketing environment was analysed in order to assist in the identification of variables that are conducive to FDI. The final section of the literature review utilised three cases to better illustrate and understand the different challenges, market entry strategies and long-term implications of FDI. In this study, the independent variables (international marketing environment, stakeholder intervention, government considerations, resources and FDI incentives) were identified as influencing the mediating variable (FDI market entry strategy) and the dependent variables (competitiveness, sustainability, trade agreements and commitment of traders). These independent variables were selected to construct a hypothesised model and the research hypotheses. To this end, an empirical investigation was conducted, the measuring instrument used in this investigation was a questionnaire, which was assembled with the help of insights gained from secondary sources. The study respondents were selected through convenience sampling. A total of 210 respondents participated in the study, and 165 useable questionnaires were subjected to statistical analysis. The data collected for this study was subjected to five phases of analysis: exploratory factor analysis to assess validity; Cronbach’s alpha was used to test for internal consistency reliability; descriptive statistics to describe the fundamental features of the data by providing a statistical summary and analysis; and the nine hypotheses pertaining to the relationships between different variables were assessed using inferential statistical procedures, Pearson’s product correlation and regression analysis. This led to the adaptation of the hypothesised model and the hypotheses so as to indicate the changes resulting from the EFA. The findings of this study reveals that external stakeholder intervention as well as FDI incentives and resources effectively influence FDI market entry strategy in the South African business environment. The study results further reveal that the promotion of FDI market entry strategy positively influences competitiveness, sustainability, trade agreements and commitment of traders in the South African business environment. For MNCs to be successful in the expansion of FDI market entry strategy in the South African business environment, the study recommends that it is important to consider the availability of potential local partners, proximity to trading routes, reduction of the costs involved in supplying the market, the effect of tariff barriers and a competitive domestic economy. It is further recommended that MNCs need to focus on the utilisation of reliable and effective equipment in order to enable the productive management of operations in the South African business environment. The study also recommends the South African business environment as a strategic investment destination for the promotion of FDI market entry strategy as it offers low production costs in particular trading locations. This study has contributed to the field of FDI and the FDI market entry strategies employed by MNCs in South Africa. The research findings identified the international marketing (SLEPTS) factors through an assessment of the South African marketing environment, as these factors are deemed important for FDI to occur. The study also highlights the critical international marketing factors that could be used to improve local conditions through a mixture of incentives and policy re-alignment, so as to be more conducive to attracting large scale FDI. The hypothesised model developed for this study contributed to identifying the influence of external stakeholders on the successful market entry of FDI into South Africa, a critical element that MNCs usually only identify after market entry is complete. Evidence from the study shows that the South African government should direct FDI incentives towards those sectors in the economy that stand to benefit the most from the spill-over effects of FDI, in order to maximise the impact of FDI on the local economy. The research also indicates that elements such as restrictive legislation and government corruption may, to a certain degree, hinder FDI; therefore, these issues need to be addressed through legislation. It is recommended that all local efforts to attract FDI are industry or sector focussed, and that they are guided by government policies towards the greater benefit of the South African economy. Furthermore, the study found that the relationship between the host country and the MNC is critical to achieving sustainability in the long-term; therefore, it is suggested that the South African government improves its relationship with local businesses and MNCs that are looking to invest in South Africa. To conclude, it was found that South Africa has a very important role to play in attracting global FDI to Africa, as it has an accessible market based on geographic location, trade channels and traditional linkages with African and European networks.
- Full Text:
- Date Issued: 2019