Service dogs for Autism Spectrum Disorder: the experiences of caregivers in South Africa
- Authors: Martin, Emma Jeanne
- Date: 2022-04-07
- Subjects: Autism spectrum disorders South Africa , Service dogs South Africa , Animals Therapeutic use South Africa , Caregivers South Africa , Animals Therapeutic use Public opinion , Animal welfare South Africa , Children with autism spectrum disorders South Africa
- Language: English
- Type: Master's thesis , text
- Identifier: http://hdl.handle.net/10962/232855 , vital:50032
- Description: Autism spectrum disorder (ASD) is a neurodevelopmental disorder, most frequently diagnosed in childhood, with symptoms including deficits in social communication and interaction as well as restricted, repetitive patterns of behaviours, interests and activities. There is no known cure for ASD, with current treatment methods focussing upon reducing symptom severity. One such treatment method is the use of autism service dogs. Internationally, autism service dogs have been available for over two decades, while in South Africa they have only been available since 2015. A fair amount of internationally published data is available on autism service dogs, however, at the time of this research study, no data was available within South Africa. This study aimed to provide a baseline for research on autism service dogs within South Africa, by documenting the experiences of caregivers whose ASD children had been supplied with autism service dogs, with regard to the uses, effects, accessibility and public perception of the autism service dogs, as well as recommendations for future improvements of autism service dogs within South Africa. Lastly, inquiry into the welfare of the autism service dogs was sought. This study was qualitative in nature, with eight families who had been supplied with autism service dogs having chosen to participate. Data collection was achieved through one semi-structured interview with each family, which was then transcribed and thematically analysed using a hermeneutic phenomenological approach. Results indicated that autism service dogs were perceived as generally accessible, useful and beneficial for ASD children and their caregivers in a variety of ways, however, they were not without their challenges, with lifestyle adjustments and public perception being especially problematic. Participants also noted recommendations for possible future improvements. Lastly, welfare concerns for the autism service dogs relating to violent behaviour exhibited by ASD children was identified, raising the question of the suitability of service dogs for the ASD population. , Thesis (MA) -- Humanities, Psychology, 2022
- Full Text:
- Date Issued: 2022-04-07
- Authors: Martin, Emma Jeanne
- Date: 2022-04-07
- Subjects: Autism spectrum disorders South Africa , Service dogs South Africa , Animals Therapeutic use South Africa , Caregivers South Africa , Animals Therapeutic use Public opinion , Animal welfare South Africa , Children with autism spectrum disorders South Africa
- Language: English
- Type: Master's thesis , text
- Identifier: http://hdl.handle.net/10962/232855 , vital:50032
- Description: Autism spectrum disorder (ASD) is a neurodevelopmental disorder, most frequently diagnosed in childhood, with symptoms including deficits in social communication and interaction as well as restricted, repetitive patterns of behaviours, interests and activities. There is no known cure for ASD, with current treatment methods focussing upon reducing symptom severity. One such treatment method is the use of autism service dogs. Internationally, autism service dogs have been available for over two decades, while in South Africa they have only been available since 2015. A fair amount of internationally published data is available on autism service dogs, however, at the time of this research study, no data was available within South Africa. This study aimed to provide a baseline for research on autism service dogs within South Africa, by documenting the experiences of caregivers whose ASD children had been supplied with autism service dogs, with regard to the uses, effects, accessibility and public perception of the autism service dogs, as well as recommendations for future improvements of autism service dogs within South Africa. Lastly, inquiry into the welfare of the autism service dogs was sought. This study was qualitative in nature, with eight families who had been supplied with autism service dogs having chosen to participate. Data collection was achieved through one semi-structured interview with each family, which was then transcribed and thematically analysed using a hermeneutic phenomenological approach. Results indicated that autism service dogs were perceived as generally accessible, useful and beneficial for ASD children and their caregivers in a variety of ways, however, they were not without their challenges, with lifestyle adjustments and public perception being especially problematic. Participants also noted recommendations for possible future improvements. Lastly, welfare concerns for the autism service dogs relating to violent behaviour exhibited by ASD children was identified, raising the question of the suitability of service dogs for the ASD population. , Thesis (MA) -- Humanities, Psychology, 2022
- Full Text:
- Date Issued: 2022-04-07
A multispectral and machine learning approach to early stress classification in plants
- Authors: Poole, Louise Carmen
- Date: 2022-04-06
- Subjects: Machine learning , Neural networks (Computer science) , Multispectral imaging , Image processing , Plant stress detection
- Language: English
- Type: Master's thesis , text
- Identifier: http://hdl.handle.net/10962/232410 , vital:49989
- Description: Crop loss and failure can impact both a country’s economy and food security, often to devastating effects. As such, the importance of successfully detecting plant stresses early in their development is essential to minimize spread and damage to crop production. Identification of the stress and the stress-causing agent is the most critical and challenging step in plant and crop protection. With the development of and increase in ease of access to new equipment and technology in recent years, the use of spectroscopy in the early detection of plant diseases has become notably popular. This thesis narrows down the most suitable multispectral imaging techniques and machine learning algorithms for early stress detection. Datasets were collected of visible images and multispectral images. Dehydration was selected as the plant stress type for the main experiments, and data was collected from six plant species typically used in agriculture. Key contributions of this thesis include multispectral and visible datasets showing plant dehydration as well as a separate preliminary dataset on plant disease. Promising results on dehydration showed statistically significant accuracy improvements in the multispectral imaging compared to visible imaging for early stress detection, with multispectral input obtaining a 92.50% accuracy over visible input’s 77.50% on general plant species. The system was effective at stress detection on known plant species, with multispectral imaging introducing greater improvement to early stress detection than advanced stress detection. Furthermore, strong species discrimination was achieved when exclusively testing either early or advanced dehydration against healthy species. , Thesis (MSc) -- Faculty of Science, Ichthyology & Fisheries Sciences, 2022
- Full Text:
- Date Issued: 2022-04-06
- Authors: Poole, Louise Carmen
- Date: 2022-04-06
- Subjects: Machine learning , Neural networks (Computer science) , Multispectral imaging , Image processing , Plant stress detection
- Language: English
- Type: Master's thesis , text
- Identifier: http://hdl.handle.net/10962/232410 , vital:49989
- Description: Crop loss and failure can impact both a country’s economy and food security, often to devastating effects. As such, the importance of successfully detecting plant stresses early in their development is essential to minimize spread and damage to crop production. Identification of the stress and the stress-causing agent is the most critical and challenging step in plant and crop protection. With the development of and increase in ease of access to new equipment and technology in recent years, the use of spectroscopy in the early detection of plant diseases has become notably popular. This thesis narrows down the most suitable multispectral imaging techniques and machine learning algorithms for early stress detection. Datasets were collected of visible images and multispectral images. Dehydration was selected as the plant stress type for the main experiments, and data was collected from six plant species typically used in agriculture. Key contributions of this thesis include multispectral and visible datasets showing plant dehydration as well as a separate preliminary dataset on plant disease. Promising results on dehydration showed statistically significant accuracy improvements in the multispectral imaging compared to visible imaging for early stress detection, with multispectral input obtaining a 92.50% accuracy over visible input’s 77.50% on general plant species. The system was effective at stress detection on known plant species, with multispectral imaging introducing greater improvement to early stress detection than advanced stress detection. Furthermore, strong species discrimination was achieved when exclusively testing either early or advanced dehydration against healthy species. , Thesis (MSc) -- Faculty of Science, Ichthyology & Fisheries Sciences, 2022
- Full Text:
- Date Issued: 2022-04-06
Composition portfolio
- Authors: Lemmer, Elizabeth Kate
- Date: 2022-04
- Subjects: Composition (Music) , Music South Africa , COVID-19 (Disease) and the arts , Emotions in music , Violin music Scores , String quartets Scores , Chamber music Scores
- Language: English
- Type: Master's thesis , text , sheet music
- Identifier: http://hdl.handle.net/10962/232624 , vital:50008
- Description: In this portfolio I reflect on issues Covid-19 has brought to our communities and the possibilities of creating a brighter future. My music reflects the struggle that most people have faced in the last two years, the emotions and the conspiracies surrounding the experience, and the effect of solitude. In a time such as this it is almost inevitable that the music being composed is connected to the struggle in society at large. For ma composition is a journal of the heart. The pandemic has created a situation where most are out of touch with each other, have lost all previous routine and structure, where relationships are broken due to lack of personal contact, and almost everyone has unwillingly (or unwittingly) been thrust into self-reflection. Every day sees a new struggle to squeeze in all those pre-pandemic ideals so that some normalcy can be obtained, but this is not a time to be looking back. It’s a time to understand what we are going through, build new joy and excitement for this different life and learn to live the best we can with the opportunities we are given. There has not been a more important time to foster some form of connection with friends and family, and to be as strong and supportive as possible. The portfolio begins with a solo violin piece, Unwelcome Solitude, which exemplifies the loneliness and sadness during the various lockdowns over the last two years, with hints of the past and the difficulties in trying to resurrect pre-Covid-19 times. There are some unusual expressive markings to add to the descriptive effect within the piece. This is followed by The Pandemic, two serialism works: Panic and Pain scored for a string quartet. Both of these pieces apply a flexible use of serialism to emphasize out the emotional aspects of the music, and quite simply; the panic and the pain caused by Covid-19 and the country’s response to the pandemic as a whole. Finally there is a three movement chamber piece titled A Storm Series which quite literally represents the series of events that occur from the upcoming to the closure of a typical Highveld storm. Further than this, these pieces represent the series of events that occurred in South Africa from the first rumour of the Covid-19 virus starting to circle around the world, through the various lockdowns and progression of events in our country and abroad. The final movement of this series, Re-awakening, ends on a positive note representing the rainbow at the end of the storm, and the positive outlook for South Africa to keep persevering through the pandemic. , Thesis (MMus) -- Faculty of Humanities, Music and Musicology, 2022
- Full Text:
- Date Issued: 2022-04
- Authors: Lemmer, Elizabeth Kate
- Date: 2022-04
- Subjects: Composition (Music) , Music South Africa , COVID-19 (Disease) and the arts , Emotions in music , Violin music Scores , String quartets Scores , Chamber music Scores
- Language: English
- Type: Master's thesis , text , sheet music
- Identifier: http://hdl.handle.net/10962/232624 , vital:50008
- Description: In this portfolio I reflect on issues Covid-19 has brought to our communities and the possibilities of creating a brighter future. My music reflects the struggle that most people have faced in the last two years, the emotions and the conspiracies surrounding the experience, and the effect of solitude. In a time such as this it is almost inevitable that the music being composed is connected to the struggle in society at large. For ma composition is a journal of the heart. The pandemic has created a situation where most are out of touch with each other, have lost all previous routine and structure, where relationships are broken due to lack of personal contact, and almost everyone has unwillingly (or unwittingly) been thrust into self-reflection. Every day sees a new struggle to squeeze in all those pre-pandemic ideals so that some normalcy can be obtained, but this is not a time to be looking back. It’s a time to understand what we are going through, build new joy and excitement for this different life and learn to live the best we can with the opportunities we are given. There has not been a more important time to foster some form of connection with friends and family, and to be as strong and supportive as possible. The portfolio begins with a solo violin piece, Unwelcome Solitude, which exemplifies the loneliness and sadness during the various lockdowns over the last two years, with hints of the past and the difficulties in trying to resurrect pre-Covid-19 times. There are some unusual expressive markings to add to the descriptive effect within the piece. This is followed by The Pandemic, two serialism works: Panic and Pain scored for a string quartet. Both of these pieces apply a flexible use of serialism to emphasize out the emotional aspects of the music, and quite simply; the panic and the pain caused by Covid-19 and the country’s response to the pandemic as a whole. Finally there is a three movement chamber piece titled A Storm Series which quite literally represents the series of events that occur from the upcoming to the closure of a typical Highveld storm. Further than this, these pieces represent the series of events that occurred in South Africa from the first rumour of the Covid-19 virus starting to circle around the world, through the various lockdowns and progression of events in our country and abroad. The final movement of this series, Re-awakening, ends on a positive note representing the rainbow at the end of the storm, and the positive outlook for South Africa to keep persevering through the pandemic. , Thesis (MMus) -- Faculty of Humanities, Music and Musicology, 2022
- Full Text:
- Date Issued: 2022-04
The self and the impossible pursuit of justice in J.M. Coetzee’s "Waiting for the barbarians, disgrace and foe”
- Authors: Swanepoel, Elbie
- Date: 2022-04-07
- Subjects: Coetzee, J M, 1940- Criticism and interpretation , Coetzee, J M, 1940- Waiting for the barbarians , Coetzee, J M, 1940- Disgrace , Coetzee, J M, 1940- Foe , Ethics in literature , Deconstruction , Postmodernism (Literature) , Justice in literature
- Language: English
- Type: Master's thesis , text
- Identifier: http://hdl.handle.net/10962/232294 , vital:49979
- Description: In its engagement with J.M. Coetzee’s Waiting for the Barbarians, Disgrace and Foe, this thesis explores how the philosophies of Emmanuel Levinas and Jacques Derrida can be used as a framework for understanding the self’s relationship with the other. In contrast to postcolonial readings of these texts, this thesis does not consider the separation between the self and the other in terms of social or cultural differences but rather the radical alterity of the other that is perceived in the face-to-face encounter. This study aims to illustrate how the engagement with alterity exposes the instability of the self’s structures of knowledge that, in these instances, are grounded in the Western metaphysical tradition. The effects of the self’s encounter with the other are seen in the personal transformation of Coetzee’s protagonists whose initial flaws and problematic worldviews are revealed in the context of the injustices done to the other. Furthermore, the study examines the extent to which the self is complicit in the suffering of the other and how this ultimately complicates their pursuit of justice for them. While the focus of this thesis is primarily on the characters, it also shows how the writer’s careful treatment of otherness functions to confront and engage the reader with the alterity of the other and the ethical dilemmas inherent in attempting to conceptualise it. The study concludes that the protagonists’ engagement with others and their subsequent confrontation with themselves lead them to consider what an ethical response to the other might be. This ethical turn results in positive change, however ambiguously, in their thoughts about and behaviours toward other beings. , Thesis (MA) -- Faculty of Humanities, English Language and Linguistics, 2022
- Full Text:
- Date Issued: 2022-04-07
- Authors: Swanepoel, Elbie
- Date: 2022-04-07
- Subjects: Coetzee, J M, 1940- Criticism and interpretation , Coetzee, J M, 1940- Waiting for the barbarians , Coetzee, J M, 1940- Disgrace , Coetzee, J M, 1940- Foe , Ethics in literature , Deconstruction , Postmodernism (Literature) , Justice in literature
- Language: English
- Type: Master's thesis , text
- Identifier: http://hdl.handle.net/10962/232294 , vital:49979
- Description: In its engagement with J.M. Coetzee’s Waiting for the Barbarians, Disgrace and Foe, this thesis explores how the philosophies of Emmanuel Levinas and Jacques Derrida can be used as a framework for understanding the self’s relationship with the other. In contrast to postcolonial readings of these texts, this thesis does not consider the separation between the self and the other in terms of social or cultural differences but rather the radical alterity of the other that is perceived in the face-to-face encounter. This study aims to illustrate how the engagement with alterity exposes the instability of the self’s structures of knowledge that, in these instances, are grounded in the Western metaphysical tradition. The effects of the self’s encounter with the other are seen in the personal transformation of Coetzee’s protagonists whose initial flaws and problematic worldviews are revealed in the context of the injustices done to the other. Furthermore, the study examines the extent to which the self is complicit in the suffering of the other and how this ultimately complicates their pursuit of justice for them. While the focus of this thesis is primarily on the characters, it also shows how the writer’s careful treatment of otherness functions to confront and engage the reader with the alterity of the other and the ethical dilemmas inherent in attempting to conceptualise it. The study concludes that the protagonists’ engagement with others and their subsequent confrontation with themselves lead them to consider what an ethical response to the other might be. This ethical turn results in positive change, however ambiguously, in their thoughts about and behaviours toward other beings. , Thesis (MA) -- Faculty of Humanities, English Language and Linguistics, 2022
- Full Text:
- Date Issued: 2022-04-07
Enabling social learning to stimulate value creation towards a circular economy: the case of the Food for Us food redistribution mobile application development process
- Authors: Durr, Sarah Jane
- Date: 2020-04
- Subjects: Social learning South Africa Eastern Cape , Mobile apps , Circular economy South Africa Eastern Cape , Communities of practice South Africa Eastern Cape , Social networks South Africa Eastern Cape , Food for Us (Application software)
- Language: English
- Type: Master's thesis , text
- Identifier: http://hdl.handle.net/10962/245736 , vital:51401
- Description: This M.Ed. study investigates the social learning enabled by a food redistribution mobile application (app) project, Food for Us, in the Raymond Mhlaba municipality in the Eastern Cape, South Africa. Over an 18 month period, the Food for Us mobile app innovation project was piloted in two case study sites, Worcester, Western Cape, and the Raymond Mhlaba municipality, Eastern Cape, in South Africa, the latter being the focus of this study. In South Africa, one-third of the food produced for consumption is wasted; paradoxically, 26% of all households’ experience hunger. Food surplus occurs in many contexts, including communities of emerging small scale farmers, many of which are not able to find markets for their produce, resulting in wastage. In a time of mobile technology expansion, the wide infiltration of Internet-enabled smartphones into diverse communities has increased dramatically with the uptake of mobile apps being a key area of interest amongst environmental educators. The Food for Us app project aims to address the challenges of food insecurity and market access for smallscale farmers by creating an innovative technological solution in the form of a mobile app. This research project aimed to investigate the social learning that was enabled within the communities of practice that utilised and interacted with the Food for Us mobile app and Food for Us project support systems. Data was collected through a series of surveys, interviews and workshops and was analysed using Wenger, Trayner and de Laat’s (2011) Value Creation Framework. The Food for Us app pilot was not successful in the way that was originally anticipated by the Food for Us team; however, there were important social learning findings that emerged from the project which opened up a new way of looking at technological innovation in the supply chains with the small scale farming contexts. The key findings that emerged from this study indicated that technological innovation on its own is not effective in enabling deep social learning. When facilitated and supported by other networked social learning systems (such as WhatsApp group, workshops and course meetings), however, boundary crossing, intergenerational learning and network building emerged as important forms of value creation that can be enabled. Through the analysis it was noted that inhibiting factors such as app trial design, lack of critical mass participation and continued application software challenges, affected the development of value. These inhibiting factors informed recommendations around the need to develop strong social networked systems around technologically innovative solutions to promote the realisation of transformative value. , Thesis (MEd) -- Faculty of Education, Education, 2020
- Full Text:
- Date Issued: 2020-04
- Authors: Durr, Sarah Jane
- Date: 2020-04
- Subjects: Social learning South Africa Eastern Cape , Mobile apps , Circular economy South Africa Eastern Cape , Communities of practice South Africa Eastern Cape , Social networks South Africa Eastern Cape , Food for Us (Application software)
- Language: English
- Type: Master's thesis , text
- Identifier: http://hdl.handle.net/10962/245736 , vital:51401
- Description: This M.Ed. study investigates the social learning enabled by a food redistribution mobile application (app) project, Food for Us, in the Raymond Mhlaba municipality in the Eastern Cape, South Africa. Over an 18 month period, the Food for Us mobile app innovation project was piloted in two case study sites, Worcester, Western Cape, and the Raymond Mhlaba municipality, Eastern Cape, in South Africa, the latter being the focus of this study. In South Africa, one-third of the food produced for consumption is wasted; paradoxically, 26% of all households’ experience hunger. Food surplus occurs in many contexts, including communities of emerging small scale farmers, many of which are not able to find markets for their produce, resulting in wastage. In a time of mobile technology expansion, the wide infiltration of Internet-enabled smartphones into diverse communities has increased dramatically with the uptake of mobile apps being a key area of interest amongst environmental educators. The Food for Us app project aims to address the challenges of food insecurity and market access for smallscale farmers by creating an innovative technological solution in the form of a mobile app. This research project aimed to investigate the social learning that was enabled within the communities of practice that utilised and interacted with the Food for Us mobile app and Food for Us project support systems. Data was collected through a series of surveys, interviews and workshops and was analysed using Wenger, Trayner and de Laat’s (2011) Value Creation Framework. The Food for Us app pilot was not successful in the way that was originally anticipated by the Food for Us team; however, there were important social learning findings that emerged from the project which opened up a new way of looking at technological innovation in the supply chains with the small scale farming contexts. The key findings that emerged from this study indicated that technological innovation on its own is not effective in enabling deep social learning. When facilitated and supported by other networked social learning systems (such as WhatsApp group, workshops and course meetings), however, boundary crossing, intergenerational learning and network building emerged as important forms of value creation that can be enabled. Through the analysis it was noted that inhibiting factors such as app trial design, lack of critical mass participation and continued application software challenges, affected the development of value. These inhibiting factors informed recommendations around the need to develop strong social networked systems around technologically innovative solutions to promote the realisation of transformative value. , Thesis (MEd) -- Faculty of Education, Education, 2020
- Full Text:
- Date Issued: 2020-04
The diversity and dry season habitat associations of fish communities in the Kabompo River Basin, Upper Zambezi, Zambia
- Authors: Rennie, Craig Lawrence
- Date: 2022-04-06
- Subjects: Biodiversity Zambia Kabompo District , Ecology Zambia Kabompo District , Fish communities Zambia Kabompo District , Fishes Ecology Zambia Kabompo District , Freshwater habitats Zambia Kabompo District , Fishes Effect of human beings on Zambia Kabompo District , Fishes Climatic factors Zambia Kabompo District , Mesohabitat
- Language: English
- Type: Master's thesis , text
- Identifier: http://hdl.handle.net/10962/232261 , vital:49976
- Description: The Zambezian headwaters contain diverse fish communities which support thriving fisheries. This region and its fishes are under pressure from multiple anthropogenic threats, including overexploitation and large-scale developments with potential knock-on effects for the riparian communities. Previous studies have focused on known fisheries areas and the mainstem Zambezi River, neglecting large tributaries such as the Kabompo River. Consequently, little literature is available on the diversity and ecology of the fishes that inhabit these large tributaries, hindering the effective management and protection of biodiversity. This study aimed to fill the current knowledge gaps in the diversity and habitat associations of fish communities in the Upper Zambezi, using the Kabompo River as a case study. The first objective was to provide an updated checklist of the fishes of the Kabompo River basin using a compilation of historical data and field surveys. This study detailed the occurrence and distribution of 83 fish species within the Kabompo River basin. All these species have been recorded in the Upper Zambezi, with some of their ranges extending into the Middle (29 species) and Lower Zambezi (23 species) while others have more restricted distributions. The most diverse families were the Cyprinidae (26 species) and the Cichlidae (15 species). A number of potential undescribed species, whose taxonomic distinctiveness need further investigation were also collected. Taxonomic conflicts are also highlighted for some of the taxa that were previously considered to have broad geographic ranges or disjunct distributions. Consistent with findings from other studies within the region, the current taxonomy underestimates the diversity of fishes in the Kabompo River and Upper Zambezi. The second objective was to assess the habitat use of small-bodied fish communities during the low-flow period in 2019. Reconnaissance trips identified dominant mesohabitats along the middle Kabompo River around Jivundu. A total of 139 mesohabitats were sampled across the five dominant mesohabitats identified; Phragmites mauritianus, wood, rock, Vallisneria aethiopica and bare substrate. Catch per unit effort, species richness, Shannon diversity and Pielou’s evenness differed significantly between these mesohabitats. Twenty-six species showed significant associations (p < 0.05) with a specific mesohabitat type or environmental variable (current velocity or depth). Eight species were associated with the woody habitat, with three of these, E. radiatus, E. unitaeniatus, and P. ngamensis being almost exclusively associated with this habitat. Enteromius kerstenii, E. lineomaculatus and S. depressirostris were almost exclusively associated with P. mauritianus and represent potential indicator species for this habitat. A number of species were also with both P. mauritianus and woody habitats. Nine species showed statistically significant associations with the rocky mesohabitat, with Amphilius uranoscopus and Petrocephalus longicapitis, being almost exclusive to rocky sections of the river. Therefore, species such as A. uranoscopus are potential indicators for monitoring the integrity of rocky habitats under threat from sedimentation. The strong associations indicate that this comprehensive baseline may be valuable indicators/ proxies for identifying anthropogenic induced change in the Kabompo basin. This would provide a basis to determine fish responses to regional environmental changes associated with human activities. , Thesis (MSc) -- Faculty of Science, Ichthyology & Fisheries Science, 2022
- Full Text:
- Date Issued: 2022-04-06
- Authors: Rennie, Craig Lawrence
- Date: 2022-04-06
- Subjects: Biodiversity Zambia Kabompo District , Ecology Zambia Kabompo District , Fish communities Zambia Kabompo District , Fishes Ecology Zambia Kabompo District , Freshwater habitats Zambia Kabompo District , Fishes Effect of human beings on Zambia Kabompo District , Fishes Climatic factors Zambia Kabompo District , Mesohabitat
- Language: English
- Type: Master's thesis , text
- Identifier: http://hdl.handle.net/10962/232261 , vital:49976
- Description: The Zambezian headwaters contain diverse fish communities which support thriving fisheries. This region and its fishes are under pressure from multiple anthropogenic threats, including overexploitation and large-scale developments with potential knock-on effects for the riparian communities. Previous studies have focused on known fisheries areas and the mainstem Zambezi River, neglecting large tributaries such as the Kabompo River. Consequently, little literature is available on the diversity and ecology of the fishes that inhabit these large tributaries, hindering the effective management and protection of biodiversity. This study aimed to fill the current knowledge gaps in the diversity and habitat associations of fish communities in the Upper Zambezi, using the Kabompo River as a case study. The first objective was to provide an updated checklist of the fishes of the Kabompo River basin using a compilation of historical data and field surveys. This study detailed the occurrence and distribution of 83 fish species within the Kabompo River basin. All these species have been recorded in the Upper Zambezi, with some of their ranges extending into the Middle (29 species) and Lower Zambezi (23 species) while others have more restricted distributions. The most diverse families were the Cyprinidae (26 species) and the Cichlidae (15 species). A number of potential undescribed species, whose taxonomic distinctiveness need further investigation were also collected. Taxonomic conflicts are also highlighted for some of the taxa that were previously considered to have broad geographic ranges or disjunct distributions. Consistent with findings from other studies within the region, the current taxonomy underestimates the diversity of fishes in the Kabompo River and Upper Zambezi. The second objective was to assess the habitat use of small-bodied fish communities during the low-flow period in 2019. Reconnaissance trips identified dominant mesohabitats along the middle Kabompo River around Jivundu. A total of 139 mesohabitats were sampled across the five dominant mesohabitats identified; Phragmites mauritianus, wood, rock, Vallisneria aethiopica and bare substrate. Catch per unit effort, species richness, Shannon diversity and Pielou’s evenness differed significantly between these mesohabitats. Twenty-six species showed significant associations (p < 0.05) with a specific mesohabitat type or environmental variable (current velocity or depth). Eight species were associated with the woody habitat, with three of these, E. radiatus, E. unitaeniatus, and P. ngamensis being almost exclusively associated with this habitat. Enteromius kerstenii, E. lineomaculatus and S. depressirostris were almost exclusively associated with P. mauritianus and represent potential indicator species for this habitat. A number of species were also with both P. mauritianus and woody habitats. Nine species showed statistically significant associations with the rocky mesohabitat, with Amphilius uranoscopus and Petrocephalus longicapitis, being almost exclusive to rocky sections of the river. Therefore, species such as A. uranoscopus are potential indicators for monitoring the integrity of rocky habitats under threat from sedimentation. The strong associations indicate that this comprehensive baseline may be valuable indicators/ proxies for identifying anthropogenic induced change in the Kabompo basin. This would provide a basis to determine fish responses to regional environmental changes associated with human activities. , Thesis (MSc) -- Faculty of Science, Ichthyology & Fisheries Science, 2022
- Full Text:
- Date Issued: 2022-04-06
Adolescents and coaches/trainers perspectives of ergogenic sports supplement use within South African private high schools
- Authors: Butler, Nicholas John
- Date: 2022-04-06
- Subjects: Dietary supplements , Energy metabolism , Teenagers South Africa , Teenagers Physiology South Africa , Teenagers Substance use South Africa , Coaches (Athletics) South Africa , Athletic trainers South Africa , Private schools South Africa , Ergogenic aids
- Language: English
- Type: Master's thesis , text
- Identifier: http://hdl.handle.net/10962/232443 , vital:49992
- Description: Sports supplements, also referred to as ergogenic aids, are used because of the assertion that they can enhance physical or athletic performance and/or physical appearance. Commonly used sports supplements include creatines, proteins, amino acids, stimulants, and in some cases pro-hormones. There is a relatively high and increasing prevalence of sports supplement use by the general population globally and in South Africa, particularly among adolescents and young adults due to various factors. While some research has explored supplement use among adolescents in a school setting, no study has explored this across the private school system in South Africa. Additionally, given the important role that coaches/trainers play in adolescent development, it is critical to also understand the role that they play regarding adolescent supplement use, given that there has been limited research around this topic in South Africa. Therefore, there were two aims of this study; Firstly, this study explored the prevalence and perceptions (knowledge; attitudes; beliefs) of sports supplements among South African private high school adolescents. Secondly, this study explored the perceptions (knowledge; attitudes; application of knowledge) towards sports supplements among adolescent coaches/trainers in South African private high schools. Considering the dual aim of this study, this thesis was structured as a two-part research study. Both parts took the form of a cross-sectional design, using an online questionnaire to collect qualitative and quantitative data. In total, a cohort of n=50 adolescents and n=49 coaches/trainers participated. Adolescent participants reported a high prevalence of sports supplement use (62%) with their main reasons for using them being recovery and performance. Adolescents were primarily influenced/advised by friends and coaches/trainers to start using sports supplements. Coaches/trainers primarily relied on other coaches/trainers and internet advertising/sites as a main source of information. Less than half of the participants from both groups reported having any formal education or training related to sports nutrition or sports supplements. Both groups thought that these products are being misused by adolescents, which may account for why a portion of the adolescent participants reported experiencing adverse side-effects from using sports supplements, and a few coach/trainer participants reported witnessing this in their practice. This may be a result of the professionalisation of school sport which places pressure on athletes and their coaches/trainers to perform and may in turn be the reason why some adolescents reported that they would use, and some coaches/trainers reported they would recommend the use of sports supplements even if they were aware of risk/dangers involved. Thus, there is a need for education/training among South African high school adolescents and their coaches/trainers with respect to the use of sports supplements, so that they can make informed decisions from reliable sources of information or advice in order to use these products safely and effectively. , Thesis (MSc) -- Faculty of Science, Human Kinetics and Ergonomics, 2022
- Full Text:
- Date Issued: 2022-04-06
- Authors: Butler, Nicholas John
- Date: 2022-04-06
- Subjects: Dietary supplements , Energy metabolism , Teenagers South Africa , Teenagers Physiology South Africa , Teenagers Substance use South Africa , Coaches (Athletics) South Africa , Athletic trainers South Africa , Private schools South Africa , Ergogenic aids
- Language: English
- Type: Master's thesis , text
- Identifier: http://hdl.handle.net/10962/232443 , vital:49992
- Description: Sports supplements, also referred to as ergogenic aids, are used because of the assertion that they can enhance physical or athletic performance and/or physical appearance. Commonly used sports supplements include creatines, proteins, amino acids, stimulants, and in some cases pro-hormones. There is a relatively high and increasing prevalence of sports supplement use by the general population globally and in South Africa, particularly among adolescents and young adults due to various factors. While some research has explored supplement use among adolescents in a school setting, no study has explored this across the private school system in South Africa. Additionally, given the important role that coaches/trainers play in adolescent development, it is critical to also understand the role that they play regarding adolescent supplement use, given that there has been limited research around this topic in South Africa. Therefore, there were two aims of this study; Firstly, this study explored the prevalence and perceptions (knowledge; attitudes; beliefs) of sports supplements among South African private high school adolescents. Secondly, this study explored the perceptions (knowledge; attitudes; application of knowledge) towards sports supplements among adolescent coaches/trainers in South African private high schools. Considering the dual aim of this study, this thesis was structured as a two-part research study. Both parts took the form of a cross-sectional design, using an online questionnaire to collect qualitative and quantitative data. In total, a cohort of n=50 adolescents and n=49 coaches/trainers participated. Adolescent participants reported a high prevalence of sports supplement use (62%) with their main reasons for using them being recovery and performance. Adolescents were primarily influenced/advised by friends and coaches/trainers to start using sports supplements. Coaches/trainers primarily relied on other coaches/trainers and internet advertising/sites as a main source of information. Less than half of the participants from both groups reported having any formal education or training related to sports nutrition or sports supplements. Both groups thought that these products are being misused by adolescents, which may account for why a portion of the adolescent participants reported experiencing adverse side-effects from using sports supplements, and a few coach/trainer participants reported witnessing this in their practice. This may be a result of the professionalisation of school sport which places pressure on athletes and their coaches/trainers to perform and may in turn be the reason why some adolescents reported that they would use, and some coaches/trainers reported they would recommend the use of sports supplements even if they were aware of risk/dangers involved. Thus, there is a need for education/training among South African high school adolescents and their coaches/trainers with respect to the use of sports supplements, so that they can make informed decisions from reliable sources of information or advice in order to use these products safely and effectively. , Thesis (MSc) -- Faculty of Science, Human Kinetics and Ergonomics, 2022
- Full Text:
- Date Issued: 2022-04-06
The influence of financial socialisation agents on financial knowledge, financial self-efficacy and financial behaviour among South African consumers
- Authors: Maswena, Kaelo
- Date: 2022-04-06
- Subjects: Financial literacy South Africa , Finance, Personal South Africa , Budgets, Personal South Africa , Consumer behavior South Africa , Consumers Attitudes , Life skills South Africa , Social learning South Africa , Self-control South Africa , Socialization South Africa , Financial socialisation agents
- Language: English
- Type: Master's thesis , text
- Identifier: http://hdl.handle.net/10962/232421 , vital:49990
- Description: There is a need to promote positive financial behaviour in South Africa. According to the Human Sciences Research Council (2018), South African financial behaviour culture emphasises a financially vulnerable nation in terms of not having enough income for future planning and lacking financial self-control. In its key role in influencing financial behaviour, financial socialisation, which is characterised by interactions with indirect, or purposive financial education and communication of financial norms influencing financial behaviours, attitudes, knowledge, capabilities, and self-efficacy of consumers, is the topic of this study. The purpose of the study was to investigate the influence of financial socialisation agents on financial (actual and self-assessed) knowledge, financial self-efficacy and financial behaviour among South African consumers. Based on Glenn’s (2018) framework, Xiao et al. (2009) socialisation and Moschis et al. (1978) consumer socialisation theory, the financial socialisation theoretical framework is provided for this study. Literature review provided an overview of past studies on the concepts of financial socialisation, financial (actual and self-assessed) knowledge, financial self-efficacy and financial behaviour. Therefore, a positivistic research paradigm was adopted, which used a cross-sectional correlational research methodology. This study analysed data primarily collected by a questionnaire survey of South African social attitudes to financial literacy by the Human Sciences Research Council (2011), using a multi-staged sampling technique in all South African provinces of consumers of 16 years and older. Descriptive statistics showed that most respondents were black African females between the ages of 26 and 35 years. Most held Matric certificates and were in paid employment for 30 hours or more per week. Most respondents considered family to be the most influential financial socialisation agent, followed by friends, then the bank. Actual financial knowledge of respondents, was indicated as relatively high. Results on self-assessed financial knowledge showed that most of the respondents considered their level of financial knowledge to be neutral. Using Pearson product-moment correlations to measure the strength and correlations of relationships, positive significant correlations were found between financial socialisation agents, financial (actual and self-assessed) knowledge and financial self-efficacy, while a negative and insignificant correlation was found between financial socialisation agents and financial behaviour. Multiple regression analysis results testing the hypotheses of the study demonstrated that financial socialisation agents have a significant positive influence on financial (actual and self-assessed) knowledge and financial self-efficacy; a significant influence on financial behaviour was not reported. Self-assessed financial knowledge showed a positive significant influence on financial self-efficacy and actual financial knowledge had an insignificant negative influence on financial self-efficacy. Actual financial knowledge had a significant positive influence on financial behaviour, whereby a positive yet insignificant relationship was found between self-assessed knowledge and financial behaviour. In the end, recommendations for the results indicate that financial educators need to develop a financial education plan that will include other content areas of financial knowledge such as identified by Huston (2010) and Lusardi and Mitchell (2011); the most important recommendation would be to help consumers have an accurate understanding of their own level of financial knowledge and to improve financial self-efficacy in consumers, financial socialisation experiences such as offering encouragement to open a bank account, to save and invest money, and presenting opportunities to practise financial skills, may increase consumers’ self-efficacy and lead to positive financial behaviours. , Thesis (MCom) -- Faculty of Commerce, Management, 2022
- Full Text:
- Date Issued: 2022-04-06
- Authors: Maswena, Kaelo
- Date: 2022-04-06
- Subjects: Financial literacy South Africa , Finance, Personal South Africa , Budgets, Personal South Africa , Consumer behavior South Africa , Consumers Attitudes , Life skills South Africa , Social learning South Africa , Self-control South Africa , Socialization South Africa , Financial socialisation agents
- Language: English
- Type: Master's thesis , text
- Identifier: http://hdl.handle.net/10962/232421 , vital:49990
- Description: There is a need to promote positive financial behaviour in South Africa. According to the Human Sciences Research Council (2018), South African financial behaviour culture emphasises a financially vulnerable nation in terms of not having enough income for future planning and lacking financial self-control. In its key role in influencing financial behaviour, financial socialisation, which is characterised by interactions with indirect, or purposive financial education and communication of financial norms influencing financial behaviours, attitudes, knowledge, capabilities, and self-efficacy of consumers, is the topic of this study. The purpose of the study was to investigate the influence of financial socialisation agents on financial (actual and self-assessed) knowledge, financial self-efficacy and financial behaviour among South African consumers. Based on Glenn’s (2018) framework, Xiao et al. (2009) socialisation and Moschis et al. (1978) consumer socialisation theory, the financial socialisation theoretical framework is provided for this study. Literature review provided an overview of past studies on the concepts of financial socialisation, financial (actual and self-assessed) knowledge, financial self-efficacy and financial behaviour. Therefore, a positivistic research paradigm was adopted, which used a cross-sectional correlational research methodology. This study analysed data primarily collected by a questionnaire survey of South African social attitudes to financial literacy by the Human Sciences Research Council (2011), using a multi-staged sampling technique in all South African provinces of consumers of 16 years and older. Descriptive statistics showed that most respondents were black African females between the ages of 26 and 35 years. Most held Matric certificates and were in paid employment for 30 hours or more per week. Most respondents considered family to be the most influential financial socialisation agent, followed by friends, then the bank. Actual financial knowledge of respondents, was indicated as relatively high. Results on self-assessed financial knowledge showed that most of the respondents considered their level of financial knowledge to be neutral. Using Pearson product-moment correlations to measure the strength and correlations of relationships, positive significant correlations were found between financial socialisation agents, financial (actual and self-assessed) knowledge and financial self-efficacy, while a negative and insignificant correlation was found between financial socialisation agents and financial behaviour. Multiple regression analysis results testing the hypotheses of the study demonstrated that financial socialisation agents have a significant positive influence on financial (actual and self-assessed) knowledge and financial self-efficacy; a significant influence on financial behaviour was not reported. Self-assessed financial knowledge showed a positive significant influence on financial self-efficacy and actual financial knowledge had an insignificant negative influence on financial self-efficacy. Actual financial knowledge had a significant positive influence on financial behaviour, whereby a positive yet insignificant relationship was found between self-assessed knowledge and financial behaviour. In the end, recommendations for the results indicate that financial educators need to develop a financial education plan that will include other content areas of financial knowledge such as identified by Huston (2010) and Lusardi and Mitchell (2011); the most important recommendation would be to help consumers have an accurate understanding of their own level of financial knowledge and to improve financial self-efficacy in consumers, financial socialisation experiences such as offering encouragement to open a bank account, to save and invest money, and presenting opportunities to practise financial skills, may increase consumers’ self-efficacy and lead to positive financial behaviours. , Thesis (MCom) -- Faculty of Commerce, Management, 2022
- Full Text:
- Date Issued: 2022-04-06
The invasion autecology of Iris pseudacorus L. (Iridaceae) in South Africa
- Authors: Sandenbergh, Emma
- Date: 2022-04-06
- Subjects: Iris pseudacorus South Africa , Invasive plants South Africa , Aquatic weeds South Africa , Plant genetics South Africa , Freshwater ecology South Africa , Iris pseudacorus Geographical distribution , Phytogeography
- Language: English
- Type: Master's thesis , text
- Identifier: http://hdl.handle.net/10962/232272 , vital:49977
- Description: Iris pseudacorus L. (Iridaceae) is an emergent aquatic macrophyte originating from Europe, north Africa, and western Asia, and is becoming an increasingly problematic invader in South Africa. By forming dense rhizomatic mats in the absence of natural enemies, I. pseudacorus outcompetes co-occurring indigenous biota, causing serious environmental and socioeconomic challenges. Iris pseudacorus is a declared invader in South Africa, Argentina, New Zealand, the United States of America, and Canada, but little information is known regarding the species’ invasive potential, particularly in the southern hemisphere, hindering the effectiveness of control efforts. This study addresses this knowledge gap in a South African context, providing valuable insight into the invasion autecology of I. pseudacorus in South Africa. For effective management and control of I. pseudacorus in South Africa and the global south, its distribution and invasive potential must be determined, and its population genetics understood. Hence, this study aimed to map the current confirmed distribution of I. pseudacorus populations in South Africa, investigating the relative abundance of I. pseudacorus individuals in each population, and comparing their sexual reproductive outputs. Moreover, this study assessed the competitive interactions between I. pseudacorus and co-occurring native species T. capensis, and examined the genetic diversity present between and within South African I. pseudacorus populations. Through field surveys, I. pseudacorus infestations were confirmed in eight of the country’s nine provinces, with the highest number of infestations recorded in the urban hubs, and greatest population abundances reported in the warmer, wetter regions of South Africa. These surveys indicated that South African I. pseudacorus populations have enhanced their sexual reproductive output relative to native range populations, and a germination rate of ~ 83 % was determined in the laboratory. The results of a common garden competition experiment indicated that T. capensis may be a superior competitor over I. pseudacorus, but this was not supported by field observations, and may be a result of the short duration of the experiment. Using inter-simple sequence repeats (ISSRs), high genetic diversity was observed within and between populations of I. pseudacorus, indicating the employment of sexual reproductive strategies, and providing evidence for gene-flow between and within populations. Moreover, a weak negative correlation was observed between geographic distance and genetic similarity, ii indicating a largely anthropogenic spread of I. pseudacorus, and suggesting the occurrence of fewer founding events than reported in the United States. This study provides useful insight into the invasion autecology of I. pseudacorus in South Africa, contributing to the ongoing research surrounding I. pseudacorus invasions worldwide, particularly in the southern hemisphere. These results contribute to the development of appropriate adaptive and integrated management strategies to control I. pseudacorus invasions in South Africa, and should be implemented before South African I. pseudacorus infestations reach the severity observed elsewhere. , Thesis (MSc) -- Faculty of Science, Botany, 2022
- Full Text:
- Date Issued: 2022-04-06
- Authors: Sandenbergh, Emma
- Date: 2022-04-06
- Subjects: Iris pseudacorus South Africa , Invasive plants South Africa , Aquatic weeds South Africa , Plant genetics South Africa , Freshwater ecology South Africa , Iris pseudacorus Geographical distribution , Phytogeography
- Language: English
- Type: Master's thesis , text
- Identifier: http://hdl.handle.net/10962/232272 , vital:49977
- Description: Iris pseudacorus L. (Iridaceae) is an emergent aquatic macrophyte originating from Europe, north Africa, and western Asia, and is becoming an increasingly problematic invader in South Africa. By forming dense rhizomatic mats in the absence of natural enemies, I. pseudacorus outcompetes co-occurring indigenous biota, causing serious environmental and socioeconomic challenges. Iris pseudacorus is a declared invader in South Africa, Argentina, New Zealand, the United States of America, and Canada, but little information is known regarding the species’ invasive potential, particularly in the southern hemisphere, hindering the effectiveness of control efforts. This study addresses this knowledge gap in a South African context, providing valuable insight into the invasion autecology of I. pseudacorus in South Africa. For effective management and control of I. pseudacorus in South Africa and the global south, its distribution and invasive potential must be determined, and its population genetics understood. Hence, this study aimed to map the current confirmed distribution of I. pseudacorus populations in South Africa, investigating the relative abundance of I. pseudacorus individuals in each population, and comparing their sexual reproductive outputs. Moreover, this study assessed the competitive interactions between I. pseudacorus and co-occurring native species T. capensis, and examined the genetic diversity present between and within South African I. pseudacorus populations. Through field surveys, I. pseudacorus infestations were confirmed in eight of the country’s nine provinces, with the highest number of infestations recorded in the urban hubs, and greatest population abundances reported in the warmer, wetter regions of South Africa. These surveys indicated that South African I. pseudacorus populations have enhanced their sexual reproductive output relative to native range populations, and a germination rate of ~ 83 % was determined in the laboratory. The results of a common garden competition experiment indicated that T. capensis may be a superior competitor over I. pseudacorus, but this was not supported by field observations, and may be a result of the short duration of the experiment. Using inter-simple sequence repeats (ISSRs), high genetic diversity was observed within and between populations of I. pseudacorus, indicating the employment of sexual reproductive strategies, and providing evidence for gene-flow between and within populations. Moreover, a weak negative correlation was observed between geographic distance and genetic similarity, ii indicating a largely anthropogenic spread of I. pseudacorus, and suggesting the occurrence of fewer founding events than reported in the United States. This study provides useful insight into the invasion autecology of I. pseudacorus in South Africa, contributing to the ongoing research surrounding I. pseudacorus invasions worldwide, particularly in the southern hemisphere. These results contribute to the development of appropriate adaptive and integrated management strategies to control I. pseudacorus invasions in South Africa, and should be implemented before South African I. pseudacorus infestations reach the severity observed elsewhere. , Thesis (MSc) -- Faculty of Science, Botany, 2022
- Full Text:
- Date Issued: 2022-04-06
The application of a simple decision support system to address water quality contestations in the Vaal Barrage catchment, South Africa
- Authors: Chili, Asanda Sandra
- Date: 2022-04
- Subjects: Vaal Barrage (South Africa : Reservoir) , Decision support systems South Africa Vaal Barrage (Reservoir) , Water Pollution Law and legislation South Africa , Water quality South Africa Vaal Barrage (Reservoir) , Water use Law and legislation South Africa Vaal Barrage (Reservoir) , Urban watersheds South Africa Vaal Barrage (Reservoir) , Watershed management South Africa Vaal Barrage (Reservoir) , Water use licences (WUL)
- Language: English
- Type: Master's thesis , text
- Identifier: http://hdl.handle.net/10962/232204 , vital:49971
- Description: Deteriorating environmental water quality is one of the complex challenges in South Africa that threaten freshwater ecosystem health and functionality. An emerging concern is the contestation of water quality regulatory instruments such as standards in water use licences (WUL), and the resource quality objectives. In the Vaal Barrage catchment where this study was undertaken these contestations were evident, suggesting the need for both technical and social solutions to water quality changes in socio-ecological systems. The Vaal Barrage catchment within the lower section of the Upper Vaal is a highly developed, urbanised, and complex catchment supporting and contributing to the social-economic development of Gauteng Province and the entire country, as the Upper Vaal contribute 20% to the Gross Domestic Product of South Africa. This study explores the motivations for stakeholders’ contestations of water quality regulatory instruments in order to contribute to ways in which water resource users and regulators can collaboratively address water quality challenges in the Vaal Barrage catchment. The study also explores water quality scenarios and their ecological and management implications. Document analysis, participant observations and a semi-structured questionnaire were deployed to explore stakeholders’ motivations, values, and perceptions of the water quality regulatory instruments. The results were triangulated to gain better insights into research participants responses. To explore water quality management scenarios, the study applied a water quality systems assessment model Decision Support System (DSS). The DSS was recently developed as part of a bigger project within the Vaal Barrage catchment. Regarding stakeholders’ motivation for contesting water quality regulatory instruments in the catchment, the results revealed a perceived lack of scientific credibility and defensibility in the processes used for deriving standards in WUL, a lack of transparent linkage between the WUL and resource quality objectives, and the increased need for stakeholder engagement in the resource quality objective formulation process. Furthermore, the study revealed punitive measures, education and awareness, self-regulation as mechanisms to encourage compliance. The applied DSS results showed that high nutrient loads, sulphate and total dissolved solids sourced from upstream catchments contribute to water quality deterioration in the Vaal Barrage catchment. The results also showed that the Vaal Barrage catchment could not host additional licence emitters because of TDS, phosphate and nitrate levels, which pose a serious risk to the ecology of the Vaal Barrage catchment, indicating that system had exceeded its assimilative capacity for critical water quality variables. Lastly, the results evidenced the need for collaborative action by the waste emitters within the Vaal Barrage catchment, particularly collaboration between upstream and downstream waste emitters. The study has far-reaching implications for water quality management in South Africa. These include i) the need for transparent and open processes and methods for deriving standards in water use licence, ii) the need for a water quality DSS that recognises catchment hydrological complexity in deriving standards in WUL, and for linking WUL and Resource Quality Objectives (RQOs), iii) collaboration between resources users, and between the resources users and the regulators to bring pollution to acceptable levels and iv) both social and technical solutions are necessary for managing water quality challenge, particularly in a highly developed catchment such as the Vaal Barrage system. , Thesis (MSc) -- Faculty of Science, Institute for Water Research, 2022
- Full Text:
- Date Issued: 2022-04
- Authors: Chili, Asanda Sandra
- Date: 2022-04
- Subjects: Vaal Barrage (South Africa : Reservoir) , Decision support systems South Africa Vaal Barrage (Reservoir) , Water Pollution Law and legislation South Africa , Water quality South Africa Vaal Barrage (Reservoir) , Water use Law and legislation South Africa Vaal Barrage (Reservoir) , Urban watersheds South Africa Vaal Barrage (Reservoir) , Watershed management South Africa Vaal Barrage (Reservoir) , Water use licences (WUL)
- Language: English
- Type: Master's thesis , text
- Identifier: http://hdl.handle.net/10962/232204 , vital:49971
- Description: Deteriorating environmental water quality is one of the complex challenges in South Africa that threaten freshwater ecosystem health and functionality. An emerging concern is the contestation of water quality regulatory instruments such as standards in water use licences (WUL), and the resource quality objectives. In the Vaal Barrage catchment where this study was undertaken these contestations were evident, suggesting the need for both technical and social solutions to water quality changes in socio-ecological systems. The Vaal Barrage catchment within the lower section of the Upper Vaal is a highly developed, urbanised, and complex catchment supporting and contributing to the social-economic development of Gauteng Province and the entire country, as the Upper Vaal contribute 20% to the Gross Domestic Product of South Africa. This study explores the motivations for stakeholders’ contestations of water quality regulatory instruments in order to contribute to ways in which water resource users and regulators can collaboratively address water quality challenges in the Vaal Barrage catchment. The study also explores water quality scenarios and their ecological and management implications. Document analysis, participant observations and a semi-structured questionnaire were deployed to explore stakeholders’ motivations, values, and perceptions of the water quality regulatory instruments. The results were triangulated to gain better insights into research participants responses. To explore water quality management scenarios, the study applied a water quality systems assessment model Decision Support System (DSS). The DSS was recently developed as part of a bigger project within the Vaal Barrage catchment. Regarding stakeholders’ motivation for contesting water quality regulatory instruments in the catchment, the results revealed a perceived lack of scientific credibility and defensibility in the processes used for deriving standards in WUL, a lack of transparent linkage between the WUL and resource quality objectives, and the increased need for stakeholder engagement in the resource quality objective formulation process. Furthermore, the study revealed punitive measures, education and awareness, self-regulation as mechanisms to encourage compliance. The applied DSS results showed that high nutrient loads, sulphate and total dissolved solids sourced from upstream catchments contribute to water quality deterioration in the Vaal Barrage catchment. The results also showed that the Vaal Barrage catchment could not host additional licence emitters because of TDS, phosphate and nitrate levels, which pose a serious risk to the ecology of the Vaal Barrage catchment, indicating that system had exceeded its assimilative capacity for critical water quality variables. Lastly, the results evidenced the need for collaborative action by the waste emitters within the Vaal Barrage catchment, particularly collaboration between upstream and downstream waste emitters. The study has far-reaching implications for water quality management in South Africa. These include i) the need for transparent and open processes and methods for deriving standards in water use licence, ii) the need for a water quality DSS that recognises catchment hydrological complexity in deriving standards in WUL, and for linking WUL and Resource Quality Objectives (RQOs), iii) collaboration between resources users, and between the resources users and the regulators to bring pollution to acceptable levels and iv) both social and technical solutions are necessary for managing water quality challenge, particularly in a highly developed catchment such as the Vaal Barrage system. , Thesis (MSc) -- Faculty of Science, Institute for Water Research, 2022
- Full Text:
- Date Issued: 2022-04
The use of the cochineal insect, Dactylopius tomentosus Lamarck, as a biological control agent for the invasive alien thistle cholla, Cylindropuntia pallida (Rose) F.M. Knuth in South Africa
- Authors: Zozo, Ekhona
- Date: 2022-04-06
- Subjects: Cochineal insect , Thistles Biological control South Africa , Alien plants South Africa , Invasive plants South Africa , Cactus South Africa , Biological assay
- Language: English
- Type: Master's thesis , text
- Identifier: http://hdl.handle.net/10962/233823 , vital:50131
- Description: Cylindropuntia pallida (Rose) F.M. Knuth (Cactaceae) is an invasive alien plant in South Africa indigenous in the southern U.S.A. and Mexico. Large infestations of this species can be found in the Kalahari and arid Karoo regions of South Africa, which is also present in Namibia. Because it is a very spiny cactus, dense infestations have a negative impact on agriculture and natural ecosystems. This cactus has become naturalised to the extent that eradication is impossible and the negative impacts are steadily increasing due to its increasing distribution and density. The cochineal insect, Dactylopius tomentosus Lamarck (Dactylopiidae), is native in Mexico and parts of North America, such as Texas, Arizona, and New Mexico in the U.S.A. This cochineal species is highly specialized and associated only with Cylindropuntia species, a group of cacti that are primarily restricted to the same areas. It has been introduced into Australia and South Africa as a biological control agent to control various invasive alien Cylindropuntia species. This cochineal species has several biotypes specific to certain Cylindropuntia species hosts. A biotype is a clade that cannot be differentiated morphologically from others but has different host ranges and impacts depending on the host plant species. Included amongst biotypes that have been released in South Africa are D. tomentosus ‘imbricata’ and D. tomentosus ‘cholla’ for the biological control of Cylindropuntia imbricata (Haw.) F.M. Knuth (Cactaceae) and Cylindropuntia fulgida (Engelmann) F.M. Knuth var. mamillata (Schott ex Engelmann) Backeb. (Cactaceae), respectively. These biotypes have resulted in both host plants being under substantial control in South Africa. The first part of this thesis evaluated which of the two D. tomentosus biotypes already in use in South Africa could be an effective biological control agent for C. pallida. This was done by assessing the fitness of the cochineals on the three cactus species and assessing the impact that each of the cochineals has on each of the target weed species. Should these biotypes prove ineffective, there is a third biotype, namely D. tomentosus ‘californica var. parkerii’, which researchers in Australia have worked on and have found to be suitably host-specific for release in Australia and suitably damaging to C. pallida in that country. Therefore, this new biotype could be released in South Africa if it is required. Sexually compatible biological control agents, especially those closely related and occurring in close spatial proximity to one another, may interbreed and the impacts of this hybridisation are difficult to predict. It is important to understand the outcomes of the hybridisation of cochineal because it can affect the impact of the biological control agents and thus the control of the target weed. The second part of this thesis investigated the impacts of the hybridisation of the two cochineal biotypes by assessing the damage the agents would have on the target weed, and on C. imbricata and C. fulgida var. mamillata, in the presence of one or both cochineal biotypes. The ‘cholla’ biotype performed better on C. pallida than the ‘imbricata’ biotype, but neither biotype could control C. pallida to an extent similar to the control they provide for their respective target weeds, C. imbricata and C. fulgida var. mamillata. Both the ‘cholla’ biotype and hybrids of the two biotypes of cochineal were effective at killing C. pallida when both C. imbricata and C. fulgida var. mamillata were also present. This suggests that the ‘cholla’ or hybrids may be effective at controlling C. pallida when either C. imbricata or C. fulgida var. mamillata are also present in the field due to the high population density of cochineal that results under these circumstances. There are, however, many C. pallida infestations in South Africa where the plant is problematic and is isolated from other Cylindropuntia species, and these populations are unlikely to be controlled by the ‘cholla’ biotype or the hybrids. Neither of the cochineal biotypes that are used for biological control in South Africa are suitably damaging to C. pallida to warrant their use as biological control agents for this species. Dactylopius tomentosus ‘californica var. parkerii’ is therefore recommended for release based on its host-specificity and impact to C. pallida in Australia. , Thesis (PhD) -- Faculty of Science, Zoology and Entomology, 2022
- Full Text:
- Date Issued: 2022-04-06
- Authors: Zozo, Ekhona
- Date: 2022-04-06
- Subjects: Cochineal insect , Thistles Biological control South Africa , Alien plants South Africa , Invasive plants South Africa , Cactus South Africa , Biological assay
- Language: English
- Type: Master's thesis , text
- Identifier: http://hdl.handle.net/10962/233823 , vital:50131
- Description: Cylindropuntia pallida (Rose) F.M. Knuth (Cactaceae) is an invasive alien plant in South Africa indigenous in the southern U.S.A. and Mexico. Large infestations of this species can be found in the Kalahari and arid Karoo regions of South Africa, which is also present in Namibia. Because it is a very spiny cactus, dense infestations have a negative impact on agriculture and natural ecosystems. This cactus has become naturalised to the extent that eradication is impossible and the negative impacts are steadily increasing due to its increasing distribution and density. The cochineal insect, Dactylopius tomentosus Lamarck (Dactylopiidae), is native in Mexico and parts of North America, such as Texas, Arizona, and New Mexico in the U.S.A. This cochineal species is highly specialized and associated only with Cylindropuntia species, a group of cacti that are primarily restricted to the same areas. It has been introduced into Australia and South Africa as a biological control agent to control various invasive alien Cylindropuntia species. This cochineal species has several biotypes specific to certain Cylindropuntia species hosts. A biotype is a clade that cannot be differentiated morphologically from others but has different host ranges and impacts depending on the host plant species. Included amongst biotypes that have been released in South Africa are D. tomentosus ‘imbricata’ and D. tomentosus ‘cholla’ for the biological control of Cylindropuntia imbricata (Haw.) F.M. Knuth (Cactaceae) and Cylindropuntia fulgida (Engelmann) F.M. Knuth var. mamillata (Schott ex Engelmann) Backeb. (Cactaceae), respectively. These biotypes have resulted in both host plants being under substantial control in South Africa. The first part of this thesis evaluated which of the two D. tomentosus biotypes already in use in South Africa could be an effective biological control agent for C. pallida. This was done by assessing the fitness of the cochineals on the three cactus species and assessing the impact that each of the cochineals has on each of the target weed species. Should these biotypes prove ineffective, there is a third biotype, namely D. tomentosus ‘californica var. parkerii’, which researchers in Australia have worked on and have found to be suitably host-specific for release in Australia and suitably damaging to C. pallida in that country. Therefore, this new biotype could be released in South Africa if it is required. Sexually compatible biological control agents, especially those closely related and occurring in close spatial proximity to one another, may interbreed and the impacts of this hybridisation are difficult to predict. It is important to understand the outcomes of the hybridisation of cochineal because it can affect the impact of the biological control agents and thus the control of the target weed. The second part of this thesis investigated the impacts of the hybridisation of the two cochineal biotypes by assessing the damage the agents would have on the target weed, and on C. imbricata and C. fulgida var. mamillata, in the presence of one or both cochineal biotypes. The ‘cholla’ biotype performed better on C. pallida than the ‘imbricata’ biotype, but neither biotype could control C. pallida to an extent similar to the control they provide for their respective target weeds, C. imbricata and C. fulgida var. mamillata. Both the ‘cholla’ biotype and hybrids of the two biotypes of cochineal were effective at killing C. pallida when both C. imbricata and C. fulgida var. mamillata were also present. This suggests that the ‘cholla’ or hybrids may be effective at controlling C. pallida when either C. imbricata or C. fulgida var. mamillata are also present in the field due to the high population density of cochineal that results under these circumstances. There are, however, many C. pallida infestations in South Africa where the plant is problematic and is isolated from other Cylindropuntia species, and these populations are unlikely to be controlled by the ‘cholla’ biotype or the hybrids. Neither of the cochineal biotypes that are used for biological control in South Africa are suitably damaging to C. pallida to warrant their use as biological control agents for this species. Dactylopius tomentosus ‘californica var. parkerii’ is therefore recommended for release based on its host-specificity and impact to C. pallida in Australia. , Thesis (PhD) -- Faculty of Science, Zoology and Entomology, 2022
- Full Text:
- Date Issued: 2022-04-06
Pink Concrete
- Authors: Curr, Jill Alexandra
- Date: 2022-04-07
- Subjects: Creative writing (Higher education) South Africa , Diaries -- Authorship , South African fiction (English) 21st century , English fiction History and criticism , Nigerian fiction (English) History and criticism , Argentine fiction History and criticism , Angolan fiction (Portuguese) History and criticism
- Language: English
- Type: Master's thesis , text
- Identifier: http://hdl.handle.net/10962/232388 , vital:49987
- Description: (From Reader Report Reflection) - I started this course believing I was not a writer. I knew that I loved to write, I knew that it was innate to how I perceived the world. I had written a novel previously, it was an outpouring, uncontrollable imagination spew. I was often scared and doubted myself throughout writing it, but I took comfort in my reading. I picked up all the classics, modern and old, rewriting the words into notebooks alongside my own, retracing the sounds, the rhythms, the symbols and their little links, the pauses. I collected pieces rereading them with reverence, my fingers curling over the lines sunken into the page. I didn’t understand what I was doing, it felt natural to hide in the skirts of other writers peering behind the curtain to see how they built the illusion. And yet, even after finishing my novel I still didn’t think I was a writer; it was a hobby, it was something extra to me, a backpack I could take off and on. I denied what was innate, and said it was not that important to me. I applied for this Master’s in Creative Writing (MACW)7 course because I wanted external validation on my first novel and an application was probably the only way, I was going to get someone to read it. It is sad and stunted that I needed this external validation to believe I could try, to believe that I could learn to control this compulsion, to believe that I could become a writer. In our first course contact week,8 lecturers and supervisors kept saying again again that we were already writers, that this is what we are. I was scared of this, that they would find out I was not really meant to be here. Writing, taking those solitary thoughts that are too much for my skull and making them real, something tangible; this is how I move through my existence. I take pieces of myself and paste them to the page, otherwise the thoughts build up like snow around a car until you are suffocating in an icebox. And by removing this part of myself to just a hobby, a silly backpack that I can pick up and put down, was just me running away. This MACW course gave me the tools to tap into what I am, that I have a why that I must write to and that I have an audience for this why. By sharing pieces of myself, I make them real again, something I can study, tracing their edges, their dark underbelly, the light hillocks. I sat with my fear for two years slowly, piece by piece, cracking it open. I learnt to love my voice and believe in it without needing external validation, without needing the gold star of acceptance, because I accept and love what I am trying to build with my writing. , Thesis (MACW) -- Faculty of Arts, School of Languages and Literatures, 2022
- Full Text:
- Date Issued: 2022-04-07
- Authors: Curr, Jill Alexandra
- Date: 2022-04-07
- Subjects: Creative writing (Higher education) South Africa , Diaries -- Authorship , South African fiction (English) 21st century , English fiction History and criticism , Nigerian fiction (English) History and criticism , Argentine fiction History and criticism , Angolan fiction (Portuguese) History and criticism
- Language: English
- Type: Master's thesis , text
- Identifier: http://hdl.handle.net/10962/232388 , vital:49987
- Description: (From Reader Report Reflection) - I started this course believing I was not a writer. I knew that I loved to write, I knew that it was innate to how I perceived the world. I had written a novel previously, it was an outpouring, uncontrollable imagination spew. I was often scared and doubted myself throughout writing it, but I took comfort in my reading. I picked up all the classics, modern and old, rewriting the words into notebooks alongside my own, retracing the sounds, the rhythms, the symbols and their little links, the pauses. I collected pieces rereading them with reverence, my fingers curling over the lines sunken into the page. I didn’t understand what I was doing, it felt natural to hide in the skirts of other writers peering behind the curtain to see how they built the illusion. And yet, even after finishing my novel I still didn’t think I was a writer; it was a hobby, it was something extra to me, a backpack I could take off and on. I denied what was innate, and said it was not that important to me. I applied for this Master’s in Creative Writing (MACW)7 course because I wanted external validation on my first novel and an application was probably the only way, I was going to get someone to read it. It is sad and stunted that I needed this external validation to believe I could try, to believe that I could learn to control this compulsion, to believe that I could become a writer. In our first course contact week,8 lecturers and supervisors kept saying again again that we were already writers, that this is what we are. I was scared of this, that they would find out I was not really meant to be here. Writing, taking those solitary thoughts that are too much for my skull and making them real, something tangible; this is how I move through my existence. I take pieces of myself and paste them to the page, otherwise the thoughts build up like snow around a car until you are suffocating in an icebox. And by removing this part of myself to just a hobby, a silly backpack that I can pick up and put down, was just me running away. This MACW course gave me the tools to tap into what I am, that I have a why that I must write to and that I have an audience for this why. By sharing pieces of myself, I make them real again, something I can study, tracing their edges, their dark underbelly, the light hillocks. I sat with my fear for two years slowly, piece by piece, cracking it open. I learnt to love my voice and believe in it without needing external validation, without needing the gold star of acceptance, because I accept and love what I am trying to build with my writing. , Thesis (MACW) -- Faculty of Arts, School of Languages and Literatures, 2022
- Full Text:
- Date Issued: 2022-04-07
Magnitude
- Authors: Seddon, Deborah Ann
- Date: 2022-04-07
- Subjects: Creative writing (Higher education) South Africa , Zimbabwean poetry (English) 21st century , Diaries -- Authorship , Polish literature 21st century History and criticism , English poetry 20th century History and criticism , English literature Irish authors History and criticism , American poetry 21st century History and criticism
- Language: English
- Type: Master's thesis , text
- Identifier: http://hdl.handle.net/10962/234400 , vital:50192
- Description: My thesis is a collection of lyric, narrative, and prose poetry directed towards two forms of death – physical death and the disavowal of the self. Many poems focus on the death of my mother, and the work required after loss to sort through a family’s life in my Harare childhood home. This associative exploration draws together childhood memories, encounters with physical objects, letters, and songs, as well as with the city and its people. Tadeusz Rózewicz’s Mother Departs has influenced my approach to writing of my mother’s death, particularly how to grant her a voice in the telling. I also draw on the poetry of Harmony Holiday and Pascal Petite, in their attention to the complexities and emotional dangers of the mother-daughter bond. Other poems draw on the work of Adrienne Rich, Audre Lorde, Judy Grahn, Ocean Vuong, and Saeed Jones, in terms of imagining queer life into poetry, the use of the erotic as a means of empowerment, and developing a queer political identity, to examine various aspects of queer love, including the heartaches associated with self-denial. , Thesis (MA) -- Faculty of Humanities, School of Languages and Literatures, 2022
- Full Text:
- Date Issued: 2022-04-07
- Authors: Seddon, Deborah Ann
- Date: 2022-04-07
- Subjects: Creative writing (Higher education) South Africa , Zimbabwean poetry (English) 21st century , Diaries -- Authorship , Polish literature 21st century History and criticism , English poetry 20th century History and criticism , English literature Irish authors History and criticism , American poetry 21st century History and criticism
- Language: English
- Type: Master's thesis , text
- Identifier: http://hdl.handle.net/10962/234400 , vital:50192
- Description: My thesis is a collection of lyric, narrative, and prose poetry directed towards two forms of death – physical death and the disavowal of the self. Many poems focus on the death of my mother, and the work required after loss to sort through a family’s life in my Harare childhood home. This associative exploration draws together childhood memories, encounters with physical objects, letters, and songs, as well as with the city and its people. Tadeusz Rózewicz’s Mother Departs has influenced my approach to writing of my mother’s death, particularly how to grant her a voice in the telling. I also draw on the poetry of Harmony Holiday and Pascal Petite, in their attention to the complexities and emotional dangers of the mother-daughter bond. Other poems draw on the work of Adrienne Rich, Audre Lorde, Judy Grahn, Ocean Vuong, and Saeed Jones, in terms of imagining queer life into poetry, the use of the erotic as a means of empowerment, and developing a queer political identity, to examine various aspects of queer love, including the heartaches associated with self-denial. , Thesis (MA) -- Faculty of Humanities, School of Languages and Literatures, 2022
- Full Text:
- Date Issued: 2022-04-07
Visualisation processes in teaching patterns and their generalisation: perceptions and experiences from senior phase mathematics teachers
- Authors: Chatima, Simon
- Date: 2022-04-08
- Subjects: Visual learning South Africa Eastern Cape , Mathematics Study and teaching (Secondary) South Africa Eastern Cape , Mathematics teachers South Africa Eastern Cape Attitudes , Sequences (Mathematics) Study and teaching (Secondary) South Africa Eastern Cape , Constructivism (Education) South Africa Eastern Cape , Mathematics teachers In-service training South Africa Eastern Cape , VIPRO MATHS Project
- Language: English
- Type: Master's thesis , text
- Identifier: http://hdl.handle.net/10962/232936 , vital:50039
- Description: This study investigated how senior phase mathematics teachers used visualisation approaches to teach patterns and their generalisation as a result of an intervention programme. This project is an integral component of the VIPRO MATHS Project and one of a number of post-graduate research projects which has a particular focus on visualisation processes in mathematics education in the Southern African region. This case study of Senior Phase mathematics teachers in the Chris Hani West District (CHW) in the Eastern Cape Province of South Africa used a social constructivist theory. The study is grounded within an interpretive paradigm explanatory qualitative method design. It surveyed thirty-seven Senior Phase mathematics teachers from schools in the CHW district to get an idea of how teachers teach patterns and their generalisation, prior to an intervention process. After the survey, nine teachers were purposively selected to take part in an intervention programme. They were then observed (teaching) and interviewed to get their perceptions about what factors enable and/or constrain the teaching of patterns and their generalisation when visualisation approaches were used. The data from the survey questionnaire responses, the lesson observations and the interviews were analysed qualitatively. The findings from the survey questionnaire responses revealed that teachers in CHW district value the use of visualisation approaches, although they used visuals to teach patterns in a way that lacked depth, skill and rigor prior to the intervention. Challenges such as difficulty in keeping abreast with the prescribed syllabus, the lack of resources, time constraints, and the limited knowledge of algebra learners have for successfully transferring pictorial representations to symbolic presentations, emerged from the survey data. This necessitated the need for an intervention which focused on the use of a variety of visual strategies and tools to teach patterns and their generalisation effectively. Data from lesson observations showed that all observed participant teachers used visuals to generate image- related questions and created platforms for lively classroom discussions. The teachers used the generated questions to build on learners’ prior knowledge and to promote learner understanding of pattern dynamics that stem from pictorial representations. The data from the interviews revealed that teachers’ perceptions had drastically changed after the intervention. This was because they were now equipped and empowered to effectively make use of visual strategies that enabled them to: build on learners’ prior knowledge, to manipulate visuals for the purpose of prompting learning, develop cognitive perception in learners, cultivate learner innovation and originality and enhance problem solving techniques. This study concludes that the use of visuals enhanced conceptual teaching of patterns and their generalisation in the observed participants. This has the potential to provide mathematics education researchers and curriculum developers with a strong basis to include visualisation processes and strategies into the design of policy documents and to initiate further research efforts. The implications for the teachers are that learners need to be taught ways to create and interpret visual representations in order to understand the dynamics of transferring a pictorial pattern to its resultant symbolic representation expressing pattern regularity. It is also hoped that the results of this study will be utilised by mathematics subject advisers and teacher training institutions to improve the teaching of patterns and their generalisation. , Thesis (MEd) -- Faculty of Education, Education, 2022
- Full Text:
- Date Issued: 2022-04-08
- Authors: Chatima, Simon
- Date: 2022-04-08
- Subjects: Visual learning South Africa Eastern Cape , Mathematics Study and teaching (Secondary) South Africa Eastern Cape , Mathematics teachers South Africa Eastern Cape Attitudes , Sequences (Mathematics) Study and teaching (Secondary) South Africa Eastern Cape , Constructivism (Education) South Africa Eastern Cape , Mathematics teachers In-service training South Africa Eastern Cape , VIPRO MATHS Project
- Language: English
- Type: Master's thesis , text
- Identifier: http://hdl.handle.net/10962/232936 , vital:50039
- Description: This study investigated how senior phase mathematics teachers used visualisation approaches to teach patterns and their generalisation as a result of an intervention programme. This project is an integral component of the VIPRO MATHS Project and one of a number of post-graduate research projects which has a particular focus on visualisation processes in mathematics education in the Southern African region. This case study of Senior Phase mathematics teachers in the Chris Hani West District (CHW) in the Eastern Cape Province of South Africa used a social constructivist theory. The study is grounded within an interpretive paradigm explanatory qualitative method design. It surveyed thirty-seven Senior Phase mathematics teachers from schools in the CHW district to get an idea of how teachers teach patterns and their generalisation, prior to an intervention process. After the survey, nine teachers were purposively selected to take part in an intervention programme. They were then observed (teaching) and interviewed to get their perceptions about what factors enable and/or constrain the teaching of patterns and their generalisation when visualisation approaches were used. The data from the survey questionnaire responses, the lesson observations and the interviews were analysed qualitatively. The findings from the survey questionnaire responses revealed that teachers in CHW district value the use of visualisation approaches, although they used visuals to teach patterns in a way that lacked depth, skill and rigor prior to the intervention. Challenges such as difficulty in keeping abreast with the prescribed syllabus, the lack of resources, time constraints, and the limited knowledge of algebra learners have for successfully transferring pictorial representations to symbolic presentations, emerged from the survey data. This necessitated the need for an intervention which focused on the use of a variety of visual strategies and tools to teach patterns and their generalisation effectively. Data from lesson observations showed that all observed participant teachers used visuals to generate image- related questions and created platforms for lively classroom discussions. The teachers used the generated questions to build on learners’ prior knowledge and to promote learner understanding of pattern dynamics that stem from pictorial representations. The data from the interviews revealed that teachers’ perceptions had drastically changed after the intervention. This was because they were now equipped and empowered to effectively make use of visual strategies that enabled them to: build on learners’ prior knowledge, to manipulate visuals for the purpose of prompting learning, develop cognitive perception in learners, cultivate learner innovation and originality and enhance problem solving techniques. This study concludes that the use of visuals enhanced conceptual teaching of patterns and their generalisation in the observed participants. This has the potential to provide mathematics education researchers and curriculum developers with a strong basis to include visualisation processes and strategies into the design of policy documents and to initiate further research efforts. The implications for the teachers are that learners need to be taught ways to create and interpret visual representations in order to understand the dynamics of transferring a pictorial pattern to its resultant symbolic representation expressing pattern regularity. It is also hoped that the results of this study will be utilised by mathematics subject advisers and teacher training institutions to improve the teaching of patterns and their generalisation. , Thesis (MEd) -- Faculty of Education, Education, 2022
- Full Text:
- Date Issued: 2022-04-08
A Smaller Circle
- Authors: Bhikha, Nasira
- Date: 2022-04
- Subjects: Creative writing (Higher education) South Africa , South African fiction (English) 21st century , Short stories, South African (English) 21st century , Diaries -- Authorship , Autobiography , Short stories, English History and criticism , American fiction History and criticism , Mexican fiction History and criticism
- Language: English
- Type: Master's thesis , text
- Identifier: http://hdl.handle.net/10962/232427 , vital:49991
- Description: My thesis is a collection of prose forms weaving my identity as a South African woman of colour, my observations of life through personal, cultural and sociological lenses, where traditions are constantly challenged and evolving. The collection focuses on the untold and unresolved, using fiction as a tool of pushback and psychological reflection. I am motivated by writers who use what I would term reflective expressionism to evoke empathy by tapping into innate, universal emotions. In particular Tiff Holland’s vivid telling of family in the novella Betty Superman where she navigates complex relationships, and bell hooks’ memoirs Bone Black: Memories of Girlhood written as poetic vignettes in fluctuating points of view to draw attention to the intricacies of social structures. Joanna Walsh’s Vertigo has strongly influenced my approach to writing through her compelling imagery and use of motif in fragmented prose that delves into the psyche of her characters. I am also inspired by Lidia Yuknavitch’s visceral use of language, identifying with her invitation: “You deserve to sit at the table. The radiance falls on all of us.” , Thesis (MACW) -- Faculty of Humanities, School of Languages, 2022
- Full Text:
- Date Issued: 2022-04
- Authors: Bhikha, Nasira
- Date: 2022-04
- Subjects: Creative writing (Higher education) South Africa , South African fiction (English) 21st century , Short stories, South African (English) 21st century , Diaries -- Authorship , Autobiography , Short stories, English History and criticism , American fiction History and criticism , Mexican fiction History and criticism
- Language: English
- Type: Master's thesis , text
- Identifier: http://hdl.handle.net/10962/232427 , vital:49991
- Description: My thesis is a collection of prose forms weaving my identity as a South African woman of colour, my observations of life through personal, cultural and sociological lenses, where traditions are constantly challenged and evolving. The collection focuses on the untold and unresolved, using fiction as a tool of pushback and psychological reflection. I am motivated by writers who use what I would term reflective expressionism to evoke empathy by tapping into innate, universal emotions. In particular Tiff Holland’s vivid telling of family in the novella Betty Superman where she navigates complex relationships, and bell hooks’ memoirs Bone Black: Memories of Girlhood written as poetic vignettes in fluctuating points of view to draw attention to the intricacies of social structures. Joanna Walsh’s Vertigo has strongly influenced my approach to writing through her compelling imagery and use of motif in fragmented prose that delves into the psyche of her characters. I am also inspired by Lidia Yuknavitch’s visceral use of language, identifying with her invitation: “You deserve to sit at the table. The radiance falls on all of us.” , Thesis (MACW) -- Faculty of Humanities, School of Languages, 2022
- Full Text:
- Date Issued: 2022-04
Towards qualifications for environmental practitioners: a study of roles and competencies of entry level environmental managers
- Authors: Dingela, Mcebisi Sidwell
- Date: 2002-04
- Subjects: Environmental management South Africa , Environmental policy South Africa , Environmental education South Africa , Vocational qualifications South Africa , Educational equalization South Africa , Occupational training South Africa , Training needs South Africa , National Qualifications Framework (NQF)
- Language: English
- Type: Master's thesis , text
- Identifier: http://hdl.handle.net/10962/245616 , vital:51388
- Description: The decision by the previous apartheid governments to deprive the black population of quality education and training has dealt both the people (student and workers) and the economy of this country a severe blow. That blow is demonstrated by the current lack of skills among the majority of people of this country, particularly the black workers who constitute the majority of the workforce. The post-apartheid government is making a strong attempt at redressing the past injustices in all its forms, of particular interest in this research project, the endeavours in the education and training sphere, specifically developments associated with the National Qualifications Framework. The passing into law of the South African Qualifications Act of 1995 and the formulation of the National Qualification Framework represent significant milestones towards redressing current education and training imbalances. In order to actualise the promises of these policies and laws, new qualifications will have to be developed. This research project explores training needs of environmental practitioners in three different contexts employing a combination of research methods, i.e. Case Study and a Survey. The research project sought to identify the roles and training needs of environmental management practitioners in fulfilling their job demands as well as for career advancement. The research also sought to identify through a survey training courses currently on offer in South Africa in the environmental management field. The cases revealed a range of roles and competencies required by 'entry-level' environmental managers. Of note was the observation that these roles were broader than what the traditional perspectives on environmental management might suggest, and competencies required included several social skills, in addition to various technical skills. The survey revealed a strong leaning towards technical competence among the majority of available training courses in environmental management; and that technical emphasis remained the case even among those courses that appeared to include at least one 'social' dimension. It thus seems that this emphasis on technical competence is not consistent with the job demands of the three studied environmental management practitioners. The research identified a need for an encompassing (broad) course or qualification at 'entry level' that would take into account the realities on the ground as they confront these practitioners on a daily basis. Such training will provide practitioners with the necessary competencies to function in this seemingly evolving field of environmental management. Suggestions to inform the development of an entry-level qualification or training programme are made as part of the recommendations flowing from the research findings. The suggested qualification 'framework' is based on generic areas identified among the research participants. More work is needed though in order to translate the suggestion into an accredited qualification. , Thesis (MEd) -- Faculty of Education, Education, 2002
- Full Text:
- Date Issued: 2002-04
- Authors: Dingela, Mcebisi Sidwell
- Date: 2002-04
- Subjects: Environmental management South Africa , Environmental policy South Africa , Environmental education South Africa , Vocational qualifications South Africa , Educational equalization South Africa , Occupational training South Africa , Training needs South Africa , National Qualifications Framework (NQF)
- Language: English
- Type: Master's thesis , text
- Identifier: http://hdl.handle.net/10962/245616 , vital:51388
- Description: The decision by the previous apartheid governments to deprive the black population of quality education and training has dealt both the people (student and workers) and the economy of this country a severe blow. That blow is demonstrated by the current lack of skills among the majority of people of this country, particularly the black workers who constitute the majority of the workforce. The post-apartheid government is making a strong attempt at redressing the past injustices in all its forms, of particular interest in this research project, the endeavours in the education and training sphere, specifically developments associated with the National Qualifications Framework. The passing into law of the South African Qualifications Act of 1995 and the formulation of the National Qualification Framework represent significant milestones towards redressing current education and training imbalances. In order to actualise the promises of these policies and laws, new qualifications will have to be developed. This research project explores training needs of environmental practitioners in three different contexts employing a combination of research methods, i.e. Case Study and a Survey. The research project sought to identify the roles and training needs of environmental management practitioners in fulfilling their job demands as well as for career advancement. The research also sought to identify through a survey training courses currently on offer in South Africa in the environmental management field. The cases revealed a range of roles and competencies required by 'entry-level' environmental managers. Of note was the observation that these roles were broader than what the traditional perspectives on environmental management might suggest, and competencies required included several social skills, in addition to various technical skills. The survey revealed a strong leaning towards technical competence among the majority of available training courses in environmental management; and that technical emphasis remained the case even among those courses that appeared to include at least one 'social' dimension. It thus seems that this emphasis on technical competence is not consistent with the job demands of the three studied environmental management practitioners. The research identified a need for an encompassing (broad) course or qualification at 'entry level' that would take into account the realities on the ground as they confront these practitioners on a daily basis. Such training will provide practitioners with the necessary competencies to function in this seemingly evolving field of environmental management. Suggestions to inform the development of an entry-level qualification or training programme are made as part of the recommendations flowing from the research findings. The suggested qualification 'framework' is based on generic areas identified among the research participants. More work is needed though in order to translate the suggestion into an accredited qualification. , Thesis (MEd) -- Faculty of Education, Education, 2002
- Full Text:
- Date Issued: 2002-04
Large and multi scale mechanistic modeling of Diels-Alder reactions
- Authors: Isamura, Bienfait Kabuyaya
- Date: 2022-04-06
- Subjects: Computational chemistry , Diels-Alder reaction , Python (Computer program language) , Reaction force theory , Fullerenes , Diolefins , AMADAR (Automated workflow for Mechanistic Analysis of Diels-Alder Reactions , ONIOM
- Language: English
- Type: Master's thesis , text
- Identifier: http://hdl.handle.net/10962/232317 , vital:49981
- Description: The [4+2] cycloaddition reaction between conjugated dienes and substituted alkenes is known as the Diels-Alder (DA) reaction, in honor of two German chemists, Otto Diels and Kurt Alder, who first reported this marvelous chemical transformation. The DA reaction is one of the most popular reactions in organic chemistry, allowing for the regio- and stereospecific establishment of six-membered rings with up to four stereogenic centers. This pericyclic reaction has found many applications in areas as diverse as natural products chemistry, polymer chemistry, and agrochemistry. Over the past decades, the mechanism of the Diels-Alder (DA) reaction has been the subject of numerous studies, dealing with questions as diverse as the mechanistic pathway, the synchronicity, the use of catalysts, the effect of solvents and salts, etc. On the other hand, as an example, fullerenes (and particularly [60] fullerene) have been found to act as good dienophiles in DA reactions to the extent that many functionalized fullerenes with interesting applications are still synthesized by reacting C60 with dienes. However, despite the very abundant literature about the mechanism of the DA reaction, some pertinent questions have been still pending, including, without being restricted to, the prediction of transition state (TS) geometries and the modeling of DA reactions involving large systems, such as those of C60 fullerene. It must be emphasized that TSs are not easy to predict and the main reason is that many existing algorithms require that the search is initiated from a good starting point (guess TS), which must be very similar to the actual TS. This problem is even more difficult when many TSs are to be located as may be the case in large-scale studies. Moreover, due to the large size of the C60 molecule, the usage of accurate high-level computational methods in the investigation of its reactivity towards dienes is computationally costly, implying the need to find the best threshold between accuracy and computational cost. Therefore, the present study was carried out to contribute to solving the problems of large-scale prediction of DA transition state geometries and the multi-scale modeling of C60 fullerene DA reactions. To address the first problem (large-scale prediction of TSs), we have developed a python program named “AMADAR”, which predicts an unlimited number of DA transition states, using only the SMILES strings of the cycloadducts. AMADAR is customizable and allows for the description of intramolecular DA reactions as well as systems resulting in competing paths. In addition, The AMADAR tool contains two separate modules that perform reaction force analyses and atomic decomposition of energy derivatives from the predicted Intrinsic Reaction Coordinates (IRC) paths. The performance of AMADAR was assessed using 2000 DA cycloadducts and showed a success rate of ~ 95%. Most of the errors were due to basis set inconsistencies or convergence issues that we are still working on. Furthermore, a set of 150 IRC paths generated by the AMADAR program were analyzed to get insight into the (a)synchronicity of DA reactions. This investigation confirmed that the reaction force constant 𝜅 (second derivatives of the system energy with respect to the reaction coordinate) was a good indicator of synchronicity in DA reactions. A close inspection of the profile of 𝜅 has enabled us to propose an alternative classification of DA reactions based on their synchronicity degree, in terms of (quasi)-synchronous, moderate asynchronous, asynchronous, and likely two-steps DA reactions. Natural population analyses seemed to indicate that the global maximum of the reaction force constant could be identified with the formation of all the bonds in the reaction site. Finally, the atomic resolution of energy derivatives suggested that the mechanism of the DA reaction involves two inner elementary processes associated with the formation of each C-C bond. A striking mechanistic difference between synchronous and asynchronous DA reactions emerging from this study is that, in asynchronous reactions, the driving and retarding forces are mainly caused by the fast and slow-forming bonds (elementary process) respectively, while in the case of synchronous ones both elementary processes retard and drive the process concomitantly and equivalently. Regarding the DA reaction of C60 fullerene that was considered to illustrate the problem of multiscale modeling, we have constructed 12 ONIOM2 and 10 ONIOM3 models combining five semi-empirical methods (AM1, PM3, PM3MM, PDDG, PM6) and the LDA(SVWN) functional in conjunction with the B3LYP/6-31G(d) level. Then, their accuracy and efficiency were assessed in comparison with the pure B3LYP/6-31G(d) level considering first the DA reaction between C60 and cyclopentadiene whose experimental data are available. Further, different DFT functionals were employed in place of the B3LYP functional to describe the higher-layer of the best ONIOM partition, and the results obtained were compared to experimental data. At this step, the ONIOM2(M06-2X/6-31 G(d): SVWN/STO-3G) model, where the higher layer encompasses the diene and pyracyclene portion of C60, was found to provide the best tradeoff between accuracy and cost, with respect to experimental data. This model showed errors lower than 2.6 and 2.0 kcal/mol for the estimation of the activation and reaction enthalpies respectively. We have also demonstrated, by comparing several ONIOM2(DFT/6-31G(d): SVWN/STO-3G) models, the importance of dispersion corrections in the accurate estimation of reaction and activation energies. Finally, we have considered a set of 21 dienes, including anthracene, 1,3-butadiene, 1,3-cyclopentadiene, furan, thiophene, selenothiophene, pyrrole and their mono-cyano and hydroxyl derivatives to get insight into the DA reaction of C60 using the best ONIOM2(M06-2X/6-31 G(d): SVWN/STO-3G) model. For a given diene and its derivatives, the analysis of frontier molecular orbitals provides a consistent explanation for the substituent effect on the activation barrier. It revealed that electron-donating (withdrawing) groups such as -OH (–CN) cut down on the activation barrier of the reaction by lowering (extending) of the HOMOdiene – LUMOC60 gap and consequently enhancing (weakening) the interaction between the two reactants. Further, the decomposition of the activation energy into the strain and interaction components suggested that, for a given diene, electron-donating groups (here –OH) diminish the height of the activation barrier not only by favoring the attractive interaction between the diene and C60, but also by reducing the strain energy of the system; the opposite effect is observed for electron-withdrawing groups (here –CN). In contrast with some previous findings on typical DA reactions, we could not infer any general rule applicable to the entire dataset for the prediction of activation energies because the latter does not correlate well with either of the TS polarity, electrophilicity of the diene, or the reaction energy. , Thesis (MSc) -- Faculty of Science, Chemistry, 2022
- Full Text:
- Date Issued: 2022-04-06
- Authors: Isamura, Bienfait Kabuyaya
- Date: 2022-04-06
- Subjects: Computational chemistry , Diels-Alder reaction , Python (Computer program language) , Reaction force theory , Fullerenes , Diolefins , AMADAR (Automated workflow for Mechanistic Analysis of Diels-Alder Reactions , ONIOM
- Language: English
- Type: Master's thesis , text
- Identifier: http://hdl.handle.net/10962/232317 , vital:49981
- Description: The [4+2] cycloaddition reaction between conjugated dienes and substituted alkenes is known as the Diels-Alder (DA) reaction, in honor of two German chemists, Otto Diels and Kurt Alder, who first reported this marvelous chemical transformation. The DA reaction is one of the most popular reactions in organic chemistry, allowing for the regio- and stereospecific establishment of six-membered rings with up to four stereogenic centers. This pericyclic reaction has found many applications in areas as diverse as natural products chemistry, polymer chemistry, and agrochemistry. Over the past decades, the mechanism of the Diels-Alder (DA) reaction has been the subject of numerous studies, dealing with questions as diverse as the mechanistic pathway, the synchronicity, the use of catalysts, the effect of solvents and salts, etc. On the other hand, as an example, fullerenes (and particularly [60] fullerene) have been found to act as good dienophiles in DA reactions to the extent that many functionalized fullerenes with interesting applications are still synthesized by reacting C60 with dienes. However, despite the very abundant literature about the mechanism of the DA reaction, some pertinent questions have been still pending, including, without being restricted to, the prediction of transition state (TS) geometries and the modeling of DA reactions involving large systems, such as those of C60 fullerene. It must be emphasized that TSs are not easy to predict and the main reason is that many existing algorithms require that the search is initiated from a good starting point (guess TS), which must be very similar to the actual TS. This problem is even more difficult when many TSs are to be located as may be the case in large-scale studies. Moreover, due to the large size of the C60 molecule, the usage of accurate high-level computational methods in the investigation of its reactivity towards dienes is computationally costly, implying the need to find the best threshold between accuracy and computational cost. Therefore, the present study was carried out to contribute to solving the problems of large-scale prediction of DA transition state geometries and the multi-scale modeling of C60 fullerene DA reactions. To address the first problem (large-scale prediction of TSs), we have developed a python program named “AMADAR”, which predicts an unlimited number of DA transition states, using only the SMILES strings of the cycloadducts. AMADAR is customizable and allows for the description of intramolecular DA reactions as well as systems resulting in competing paths. In addition, The AMADAR tool contains two separate modules that perform reaction force analyses and atomic decomposition of energy derivatives from the predicted Intrinsic Reaction Coordinates (IRC) paths. The performance of AMADAR was assessed using 2000 DA cycloadducts and showed a success rate of ~ 95%. Most of the errors were due to basis set inconsistencies or convergence issues that we are still working on. Furthermore, a set of 150 IRC paths generated by the AMADAR program were analyzed to get insight into the (a)synchronicity of DA reactions. This investigation confirmed that the reaction force constant 𝜅 (second derivatives of the system energy with respect to the reaction coordinate) was a good indicator of synchronicity in DA reactions. A close inspection of the profile of 𝜅 has enabled us to propose an alternative classification of DA reactions based on their synchronicity degree, in terms of (quasi)-synchronous, moderate asynchronous, asynchronous, and likely two-steps DA reactions. Natural population analyses seemed to indicate that the global maximum of the reaction force constant could be identified with the formation of all the bonds in the reaction site. Finally, the atomic resolution of energy derivatives suggested that the mechanism of the DA reaction involves two inner elementary processes associated with the formation of each C-C bond. A striking mechanistic difference between synchronous and asynchronous DA reactions emerging from this study is that, in asynchronous reactions, the driving and retarding forces are mainly caused by the fast and slow-forming bonds (elementary process) respectively, while in the case of synchronous ones both elementary processes retard and drive the process concomitantly and equivalently. Regarding the DA reaction of C60 fullerene that was considered to illustrate the problem of multiscale modeling, we have constructed 12 ONIOM2 and 10 ONIOM3 models combining five semi-empirical methods (AM1, PM3, PM3MM, PDDG, PM6) and the LDA(SVWN) functional in conjunction with the B3LYP/6-31G(d) level. Then, their accuracy and efficiency were assessed in comparison with the pure B3LYP/6-31G(d) level considering first the DA reaction between C60 and cyclopentadiene whose experimental data are available. Further, different DFT functionals were employed in place of the B3LYP functional to describe the higher-layer of the best ONIOM partition, and the results obtained were compared to experimental data. At this step, the ONIOM2(M06-2X/6-31 G(d): SVWN/STO-3G) model, where the higher layer encompasses the diene and pyracyclene portion of C60, was found to provide the best tradeoff between accuracy and cost, with respect to experimental data. This model showed errors lower than 2.6 and 2.0 kcal/mol for the estimation of the activation and reaction enthalpies respectively. We have also demonstrated, by comparing several ONIOM2(DFT/6-31G(d): SVWN/STO-3G) models, the importance of dispersion corrections in the accurate estimation of reaction and activation energies. Finally, we have considered a set of 21 dienes, including anthracene, 1,3-butadiene, 1,3-cyclopentadiene, furan, thiophene, selenothiophene, pyrrole and their mono-cyano and hydroxyl derivatives to get insight into the DA reaction of C60 using the best ONIOM2(M06-2X/6-31 G(d): SVWN/STO-3G) model. For a given diene and its derivatives, the analysis of frontier molecular orbitals provides a consistent explanation for the substituent effect on the activation barrier. It revealed that electron-donating (withdrawing) groups such as -OH (–CN) cut down on the activation barrier of the reaction by lowering (extending) of the HOMOdiene – LUMOC60 gap and consequently enhancing (weakening) the interaction between the two reactants. Further, the decomposition of the activation energy into the strain and interaction components suggested that, for a given diene, electron-donating groups (here –OH) diminish the height of the activation barrier not only by favoring the attractive interaction between the diene and C60, but also by reducing the strain energy of the system; the opposite effect is observed for electron-withdrawing groups (here –CN). In contrast with some previous findings on typical DA reactions, we could not infer any general rule applicable to the entire dataset for the prediction of activation energies because the latter does not correlate well with either of the TS polarity, electrophilicity of the diene, or the reaction energy. , Thesis (MSc) -- Faculty of Science, Chemistry, 2022
- Full Text:
- Date Issued: 2022-04-06
Wild Honeybush (Cyclopia intermedia) augmentation
- Authors: Michau, Paul-Luc
- Date: 2022-04-06
- Subjects: Herbal teas South Africa Joubertina , Tea trade South Africa Joubertina , Legumes Harvesting South Africa Joubertina , Legumes Planting South Africa Joubertina , Sustainable development South Africa Joubertina , Economic development Environmental aspects South Africa Joubertina , Natural resources Management South Africa Joubertina , Wild Honeybush (Cyclopia intermedia)
- Language: English
- Type: Master's thesis , text
- Identifier: http://hdl.handle.net/10962/232635 , vital:50009
- Description: Honeybush (Cyclopia spp.) is an endemic legume to the fynbos region of South Africa, and certain species of the genus are used to make health tonics. There are growing international markets for such products and, currently, wild populations of the species Cyclopia intermedia are disproportionately relied upon to support this increase. Due to the sensitivity and ecological complexity of the resource, serious concerns about sustainability and regulation have arisen. The social landscape of the resource is equally as complex, and solutions for alleviating pressure on wild populations, such as reducing or banning harvesting, and switching to commercial cultivation are untenable in every case. A possible option, which has been used in the wildflower industry, is to augment (increase) wild populations by planting seeds or seedlings directly into the veld. The main focus of this research was to explore the viability of using augmentation to boost wild populations of C. intermedia through field trials. In support of this broad aim, research objectives addressed understanding the ecological habitat conditions of the species, quantifying the economic potential of augmentation, characterizing wild populations and conducting seed germination tests. GIS methods were used to locate sites most representative of natural conditions on different post-fire aged veld on a farm in the Kouga mountains. The study characterized habitat conditions by collecting soil and vegetation samples at plots where honeybush was present and absent within close proximity. Vegetation diversity was only slightly higher in presence plots, and no clear pattern between absence and presence plots was observed for soil properties. However, post-fire site age did significantly influence certain nutrient levels. The augmentation trial results indicate that seedlings have a much higher survival rate than seeds on average. Survival success varied unpredictably between plots where wild honeybush was already present and adjacent plots where it was absent. Post-fire site age influenced seedling growth and seed survival positively with the newly burnt plots showing the best growth rates overall. The cost-benefit analysis reveals that seeds are a better option as they require low-cost inputs and carry less risk, unlike seedlings which may have higher survival but are more expensive. The study recommends using trials to assess survival before choosing an option. Out of five natural populations of honeybush that were assessed only one showed seedling recruitment and three young plants were found between two of the other sites. Growth characteristics of populations showed expected variability based on site conditions and disturbance history. Growth appears to be rapid in the first-year post disturbance, thereafter slowing down. Average stem numbers and basal circumference increased concurrently for both harvested and unharvested populations. Due to the influence of natural conditions such as slope aspect and soil properties on plant morphology, it is best to compare harvested and unharvested individuals from the same site and preferably within close proximity to minimize such differences. Using seed sourced from the same parent population is critical to preserving genetic integrity and little is understood about germination characteristics from wild C. intermedia populations. The study tested germination rates between green and brown seed and alternative collection methods. When comparisons were done within farms on two occasions collection and seed colour did have a significant influence. Overall, the influence of which farm the seeds were collected from appeared to play the biggest role in determining germination. , Thesis (MSc) -- Faculty of Science, Geography, 2022
- Full Text:
- Date Issued: 2022-04-06
- Authors: Michau, Paul-Luc
- Date: 2022-04-06
- Subjects: Herbal teas South Africa Joubertina , Tea trade South Africa Joubertina , Legumes Harvesting South Africa Joubertina , Legumes Planting South Africa Joubertina , Sustainable development South Africa Joubertina , Economic development Environmental aspects South Africa Joubertina , Natural resources Management South Africa Joubertina , Wild Honeybush (Cyclopia intermedia)
- Language: English
- Type: Master's thesis , text
- Identifier: http://hdl.handle.net/10962/232635 , vital:50009
- Description: Honeybush (Cyclopia spp.) is an endemic legume to the fynbos region of South Africa, and certain species of the genus are used to make health tonics. There are growing international markets for such products and, currently, wild populations of the species Cyclopia intermedia are disproportionately relied upon to support this increase. Due to the sensitivity and ecological complexity of the resource, serious concerns about sustainability and regulation have arisen. The social landscape of the resource is equally as complex, and solutions for alleviating pressure on wild populations, such as reducing or banning harvesting, and switching to commercial cultivation are untenable in every case. A possible option, which has been used in the wildflower industry, is to augment (increase) wild populations by planting seeds or seedlings directly into the veld. The main focus of this research was to explore the viability of using augmentation to boost wild populations of C. intermedia through field trials. In support of this broad aim, research objectives addressed understanding the ecological habitat conditions of the species, quantifying the economic potential of augmentation, characterizing wild populations and conducting seed germination tests. GIS methods were used to locate sites most representative of natural conditions on different post-fire aged veld on a farm in the Kouga mountains. The study characterized habitat conditions by collecting soil and vegetation samples at plots where honeybush was present and absent within close proximity. Vegetation diversity was only slightly higher in presence plots, and no clear pattern between absence and presence plots was observed for soil properties. However, post-fire site age did significantly influence certain nutrient levels. The augmentation trial results indicate that seedlings have a much higher survival rate than seeds on average. Survival success varied unpredictably between plots where wild honeybush was already present and adjacent plots where it was absent. Post-fire site age influenced seedling growth and seed survival positively with the newly burnt plots showing the best growth rates overall. The cost-benefit analysis reveals that seeds are a better option as they require low-cost inputs and carry less risk, unlike seedlings which may have higher survival but are more expensive. The study recommends using trials to assess survival before choosing an option. Out of five natural populations of honeybush that were assessed only one showed seedling recruitment and three young plants were found between two of the other sites. Growth characteristics of populations showed expected variability based on site conditions and disturbance history. Growth appears to be rapid in the first-year post disturbance, thereafter slowing down. Average stem numbers and basal circumference increased concurrently for both harvested and unharvested populations. Due to the influence of natural conditions such as slope aspect and soil properties on plant morphology, it is best to compare harvested and unharvested individuals from the same site and preferably within close proximity to minimize such differences. Using seed sourced from the same parent population is critical to preserving genetic integrity and little is understood about germination characteristics from wild C. intermedia populations. The study tested germination rates between green and brown seed and alternative collection methods. When comparisons were done within farms on two occasions collection and seed colour did have a significant influence. Overall, the influence of which farm the seeds were collected from appeared to play the biggest role in determining germination. , Thesis (MSc) -- Faculty of Science, Geography, 2022
- Full Text:
- Date Issued: 2022-04-06
Statistical and Mathematical Learning: an application to fraud detection and prevention
- Authors: Hamlomo, Sisipho
- Date: 2022-04-06
- Subjects: Credit card fraud , Bootstrap (Statistics) , Support vector machines , Neural networks (Computer science) , Decision trees , Machine learning , Cross-validation , Imbalanced data
- Language: English
- Type: Master's thesis , text
- Identifier: http://hdl.handle.net/10962/233795 , vital:50128
- Description: Credit card fraud is an ever-growing problem. There has been a rapid increase in the rate of fraudulent activities in recent years resulting in a considerable loss to several organizations, companies, and government agencies. Many researchers have focused on detecting fraudulent behaviours early using advanced machine learning techniques. However, credit card fraud detection is not a straightforward task since fraudulent behaviours usually differ for each attempt and the dataset is highly imbalanced, that is, the frequency of non-fraudulent cases outnumbers the frequency of fraudulent cases. In the case of the European credit card dataset, we have a ratio of approximately one fraudulent case to five hundred and seventy-eight non-fraudulent cases. Different methods were implemented to overcome this problem, namely random undersampling, one-sided sampling, SMOTE combined with Tomek links and parameter tuning. Predictive classifiers, namely logistic regression, decision trees, k-nearest neighbour, support vector machine and multilayer perceptrons, are applied to predict if a transaction is fraudulent or non-fraudulent. The model's performance is evaluated based on recall, precision, F1-score, the area under receiver operating characteristics curve, geometric mean and Matthew correlation coefficient. The results showed that the logistic regression classifier performed better than other classifiers except when the dataset was oversampled. , Thesis (MSc) -- Faculty of Science, Statistics, 2022
- Full Text:
- Date Issued: 2022-04-06
- Authors: Hamlomo, Sisipho
- Date: 2022-04-06
- Subjects: Credit card fraud , Bootstrap (Statistics) , Support vector machines , Neural networks (Computer science) , Decision trees , Machine learning , Cross-validation , Imbalanced data
- Language: English
- Type: Master's thesis , text
- Identifier: http://hdl.handle.net/10962/233795 , vital:50128
- Description: Credit card fraud is an ever-growing problem. There has been a rapid increase in the rate of fraudulent activities in recent years resulting in a considerable loss to several organizations, companies, and government agencies. Many researchers have focused on detecting fraudulent behaviours early using advanced machine learning techniques. However, credit card fraud detection is not a straightforward task since fraudulent behaviours usually differ for each attempt and the dataset is highly imbalanced, that is, the frequency of non-fraudulent cases outnumbers the frequency of fraudulent cases. In the case of the European credit card dataset, we have a ratio of approximately one fraudulent case to five hundred and seventy-eight non-fraudulent cases. Different methods were implemented to overcome this problem, namely random undersampling, one-sided sampling, SMOTE combined with Tomek links and parameter tuning. Predictive classifiers, namely logistic regression, decision trees, k-nearest neighbour, support vector machine and multilayer perceptrons, are applied to predict if a transaction is fraudulent or non-fraudulent. The model's performance is evaluated based on recall, precision, F1-score, the area under receiver operating characteristics curve, geometric mean and Matthew correlation coefficient. The results showed that the logistic regression classifier performed better than other classifiers except when the dataset was oversampled. , Thesis (MSc) -- Faculty of Science, Statistics, 2022
- Full Text:
- Date Issued: 2022-04-06
Characterising the sleep-wake behaviour of adolescents in a sample of South African high school students in Makhanda, Eastern Cape
- Authors: Mandondo, Nathasha Luleka
- Date: 2021-10-29
- Subjects: Sleep-wake cycle South Africa Makhanda , Sleep deprivation South Africa Makhanda , Academic achievement South Africa Makhanda , Mood (Psychology) South Africa Makhanda , High school students Conduct of life , Teenagers Health and hygiene South Africa Makhanda , Teenagers Sleep South Africa Makhanda , Depression in adolescence South Africa Makhanda
- Language: English
- Type: Master's thesis , text
- Identifier: http://hdl.handle.net/10962/245714 , vital:51398
- Description: Sleep plays a significant role during adolescence. Overall, sleep is essential for growth and development, cognitive function, memory consolidation, concentration, alertness, mental and physical health, as well as the overall quality of life. During adolescence though, sleep-wake behaviour has been shown to undergo drastic changes, progressing from the early ages of 11-13 years through to late adolescence while attending school. During this period, adolescents experience later bedtimes, earlier waketimes, and less than recommended sleep durations, especially on weekdays during the school term. On weekends, however, adolescents tend to further delay their bed and wake times, resulting in discrepancies between week-and-weekend sleep-wake behavior. These changes are driven by a variety of systemic factors, that include biological, psychosocial, school, and behavioural changes that adolescents experience. The interaction of systematic factors has been described as the “Perfect Storm of insufficient and inappropriately-timed sleep” (Carskadon, 2011a; Crowley et al., 2018). While previous research on adolescent sleep has been focused mainly in countries of the Global North, there has been comparatively less research in the Global South, particularly in countries like South Africa, and in out of large city centres like Johannesburg and Cape Town. It is also not known what the impact of certain demographic factors, such as learner sex, boarding/day schooling, and public/private schooling is on sleep-wake habits. Therefore, the purpose of this study was to explore the sleep-wake behaviour of a sample of late adolescents from public and private schools in Makhanda in the Eastern Cape of South Africa and to make comparisons between different groups within. Method: This study is comprised of two phases. Phase one adopted a cross-sectional design to characterise Grade 12 learners' (final year students) sleep-wake behaviour across various public and private schools. This was achieved through the administration of an amended version of the School Sleep Habits Survey (SSHS). The SSHS included questions that capture demographic information, academic performance, sleep duration at different times of the week and also incorporated scales to assess daytime sleepiness, sleep-wake behavior problems, depressive mood, and chronotype. Phase two adopted an observational descriptive design. The sleep-wake behaviour of a sample of Grade 11 learners was tracked for 9 days using the Core Consensus Sleep Diary and Actigraphy. Data were not normally distributed and were thus analysed using non-parametric statistics and all data were displayed as the median and interquartile range (no 1-3). Results: Analysed surveys totalled 231. All participants were Grade 12s (final year of high school), aged between 17-19, from three private schools (n=152) and two public schools (n=79). The sample consisted of students identifying as females (n=94) and males (n=137). Participants self-identified as either Black/African (n=73), White (n=125), Colored (n=32) and as Indian (n=1). Over half of the sample lived in boarding houses/hostels (n=130) and slightly less than half (n=95) were day scholars. For Phase One, the median obtained for self-reported sleep duration on weekdays was 07hrs (06hrs-07hrs:18min) and 08hrs (07hrs-09hrs) on the weekend (p<0.01; z=10). The median for self-reported bedtime on weeknights was 11:00 (10:30-11:30) p.m., while on the weekends, it was an hour later i.e., 12:00 a.m. (11:00 p.m. -12:37 a.m.; p<0.01; z=9.4). Self-reported waketime on weekdays was 06:20 (06:00-06:30) a.m. and it was one-hour forty minutes later on weekends i.e., 08:00 (07:00-09:00) a.m. (p<0.01; z=13). With regards to sex differences on school mornings, females reported waking up 14 minutes later than their male counterparts (p<0.01; z=-3.1). On school mornings, day scholars reported significantly earlier waketimes than boarders (p<0.01; z=8.1). The opposite was found on weekends with day scholars reporting significantly later waketimes than boarders (p<0.01; z=-4.1) while day scholars reported going to bed significantly later than boarders during weekends (p<0.01; z=-2.7). There were noteworthy differences between types of schools with public school learners reporting earlier bed (p<0.01; z=3.9) and wake times (p<0.01; z=10) than private school learners on weekdays. On the weekend, however, public school learners reporting later bed (p=0.01; z=-2.7) and wake times (p<0.01; z=-4.4) than private school learners. Overall, the Grade 12 learners scored 12 (11-15) on the depressed mood scale indicating a trend towards high self-reported depressive symptoms, and 26 (23-30) on the ME scale, which demonstrated that this sample population reflects a preference for neither evenings nor mornings. The majority (75 %; n=174) of the Grade12 learners perceived themselves as getting too little sleep, 59% (n=134) reported waking up at least once during the night and 92% (n=213) reported experiencing varying degrees of daytime sleepiness. There was a relationship between caffeine consumption and usage of electronic devices (EDs) before bedtime and some sleep parameters. Specifically, the frequency of consumption of coffee/tea and soda had a medium and positive correlation with sleep onset latency as well as to the scale of sleep-wake problems. Academic performance was also positively and significantly correlated with self-reported mean weekday waketime and negatively correlated with mean weekend sleep duration as well as Weekend Waketime Delay (WWD). For Phase Two, the median self-reported sleep duration for 14 female boarders recorded in sleep diaries i.e.,07:32 (07:22-07:55) and the total sleep time (TST) recorded by the actigraphy i.e., 07:06 (06:54-07:35) and was less than the recommended sleep duration of 8-10 hours for adolescents and not significantly different (p=0.18; z=1.3). However, median sleep duration on the weekend was significantly longer on both actigraphs (08:16; 07:22-08:40) and sleep diaries (08:24; 07:59-08:51) and not significantly different (p=0.3; z=1.1). Overall, bedtimes, waketimes, and sleep onset latency, for both weekdays and weekends, did not differ significantly between the sleep diary responses and actigraph recordings. Discussion: Adolescents in this cohort, like many around the world report weekday sleep durations that are shorter than the recommended 8-10 hours. This may probably partly be explained by later bedtimes influenced by academic obligations, bedtime autonomy, and screen time as well as early waketimes influenced by school start times as indicated in the reasons given for bedtimes. Insufficient sleep during school nights, in this cohort, likely resulted in an accumulated sleep debt which may explain the extended sleep duration and later waketimes on weekends. Weekday waketimes were probably determined by commuting and school-related demands, specifically, school start times as indicated in the reasons given for waketimes. Thus, the results of this study do, in part, align with the factors outlined in the Perfect Storm model of poorly timed and insufficient sleep in adolescents proposed by Carskadon (2011a). Personal characteristics or contextual factors, such as being a boarder or a day scholar, attending a public or private school as well sex differences, accompanied by lifestyle factors such as the consumption of caffeine and usage of electrical devices may have interacted and influenced bed and wake times, resulting in what has been termed “a Perfect Storm of insufficient and inappropriately-timed sleep” in this cohort. Conclusion: The current study provided new insight into the sleep-wake behaviour of late adolescents in Makhanda, Eastern Cape of South Africa. More research is encouraged in the South African context. This knowledge can be used to implement contextually appropriate sleep hygiene education programs in the school curriculum and on an individual level. Furthermore, the results point to the fact that early school start times, in concert with other lifestyle and personal factors may be contributing to insufficient sleep in this group. These results, therefore, highlight the need for schools in this context to consider interventions such as delaying school start times to possibly improve sleep in this context. , Thesis (MSc) -- Faculty of Science, Human Kinetics and Ergonomics, 2021
- Full Text:
- Date Issued: 2021-10-29
- Authors: Mandondo, Nathasha Luleka
- Date: 2021-10-29
- Subjects: Sleep-wake cycle South Africa Makhanda , Sleep deprivation South Africa Makhanda , Academic achievement South Africa Makhanda , Mood (Psychology) South Africa Makhanda , High school students Conduct of life , Teenagers Health and hygiene South Africa Makhanda , Teenagers Sleep South Africa Makhanda , Depression in adolescence South Africa Makhanda
- Language: English
- Type: Master's thesis , text
- Identifier: http://hdl.handle.net/10962/245714 , vital:51398
- Description: Sleep plays a significant role during adolescence. Overall, sleep is essential for growth and development, cognitive function, memory consolidation, concentration, alertness, mental and physical health, as well as the overall quality of life. During adolescence though, sleep-wake behaviour has been shown to undergo drastic changes, progressing from the early ages of 11-13 years through to late adolescence while attending school. During this period, adolescents experience later bedtimes, earlier waketimes, and less than recommended sleep durations, especially on weekdays during the school term. On weekends, however, adolescents tend to further delay their bed and wake times, resulting in discrepancies between week-and-weekend sleep-wake behavior. These changes are driven by a variety of systemic factors, that include biological, psychosocial, school, and behavioural changes that adolescents experience. The interaction of systematic factors has been described as the “Perfect Storm of insufficient and inappropriately-timed sleep” (Carskadon, 2011a; Crowley et al., 2018). While previous research on adolescent sleep has been focused mainly in countries of the Global North, there has been comparatively less research in the Global South, particularly in countries like South Africa, and in out of large city centres like Johannesburg and Cape Town. It is also not known what the impact of certain demographic factors, such as learner sex, boarding/day schooling, and public/private schooling is on sleep-wake habits. Therefore, the purpose of this study was to explore the sleep-wake behaviour of a sample of late adolescents from public and private schools in Makhanda in the Eastern Cape of South Africa and to make comparisons between different groups within. Method: This study is comprised of two phases. Phase one adopted a cross-sectional design to characterise Grade 12 learners' (final year students) sleep-wake behaviour across various public and private schools. This was achieved through the administration of an amended version of the School Sleep Habits Survey (SSHS). The SSHS included questions that capture demographic information, academic performance, sleep duration at different times of the week and also incorporated scales to assess daytime sleepiness, sleep-wake behavior problems, depressive mood, and chronotype. Phase two adopted an observational descriptive design. The sleep-wake behaviour of a sample of Grade 11 learners was tracked for 9 days using the Core Consensus Sleep Diary and Actigraphy. Data were not normally distributed and were thus analysed using non-parametric statistics and all data were displayed as the median and interquartile range (no 1-3). Results: Analysed surveys totalled 231. All participants were Grade 12s (final year of high school), aged between 17-19, from three private schools (n=152) and two public schools (n=79). The sample consisted of students identifying as females (n=94) and males (n=137). Participants self-identified as either Black/African (n=73), White (n=125), Colored (n=32) and as Indian (n=1). Over half of the sample lived in boarding houses/hostels (n=130) and slightly less than half (n=95) were day scholars. For Phase One, the median obtained for self-reported sleep duration on weekdays was 07hrs (06hrs-07hrs:18min) and 08hrs (07hrs-09hrs) on the weekend (p<0.01; z=10). The median for self-reported bedtime on weeknights was 11:00 (10:30-11:30) p.m., while on the weekends, it was an hour later i.e., 12:00 a.m. (11:00 p.m. -12:37 a.m.; p<0.01; z=9.4). Self-reported waketime on weekdays was 06:20 (06:00-06:30) a.m. and it was one-hour forty minutes later on weekends i.e., 08:00 (07:00-09:00) a.m. (p<0.01; z=13). With regards to sex differences on school mornings, females reported waking up 14 minutes later than their male counterparts (p<0.01; z=-3.1). On school mornings, day scholars reported significantly earlier waketimes than boarders (p<0.01; z=8.1). The opposite was found on weekends with day scholars reporting significantly later waketimes than boarders (p<0.01; z=-4.1) while day scholars reported going to bed significantly later than boarders during weekends (p<0.01; z=-2.7). There were noteworthy differences between types of schools with public school learners reporting earlier bed (p<0.01; z=3.9) and wake times (p<0.01; z=10) than private school learners on weekdays. On the weekend, however, public school learners reporting later bed (p=0.01; z=-2.7) and wake times (p<0.01; z=-4.4) than private school learners. Overall, the Grade 12 learners scored 12 (11-15) on the depressed mood scale indicating a trend towards high self-reported depressive symptoms, and 26 (23-30) on the ME scale, which demonstrated that this sample population reflects a preference for neither evenings nor mornings. The majority (75 %; n=174) of the Grade12 learners perceived themselves as getting too little sleep, 59% (n=134) reported waking up at least once during the night and 92% (n=213) reported experiencing varying degrees of daytime sleepiness. There was a relationship between caffeine consumption and usage of electronic devices (EDs) before bedtime and some sleep parameters. Specifically, the frequency of consumption of coffee/tea and soda had a medium and positive correlation with sleep onset latency as well as to the scale of sleep-wake problems. Academic performance was also positively and significantly correlated with self-reported mean weekday waketime and negatively correlated with mean weekend sleep duration as well as Weekend Waketime Delay (WWD). For Phase Two, the median self-reported sleep duration for 14 female boarders recorded in sleep diaries i.e.,07:32 (07:22-07:55) and the total sleep time (TST) recorded by the actigraphy i.e., 07:06 (06:54-07:35) and was less than the recommended sleep duration of 8-10 hours for adolescents and not significantly different (p=0.18; z=1.3). However, median sleep duration on the weekend was significantly longer on both actigraphs (08:16; 07:22-08:40) and sleep diaries (08:24; 07:59-08:51) and not significantly different (p=0.3; z=1.1). Overall, bedtimes, waketimes, and sleep onset latency, for both weekdays and weekends, did not differ significantly between the sleep diary responses and actigraph recordings. Discussion: Adolescents in this cohort, like many around the world report weekday sleep durations that are shorter than the recommended 8-10 hours. This may probably partly be explained by later bedtimes influenced by academic obligations, bedtime autonomy, and screen time as well as early waketimes influenced by school start times as indicated in the reasons given for bedtimes. Insufficient sleep during school nights, in this cohort, likely resulted in an accumulated sleep debt which may explain the extended sleep duration and later waketimes on weekends. Weekday waketimes were probably determined by commuting and school-related demands, specifically, school start times as indicated in the reasons given for waketimes. Thus, the results of this study do, in part, align with the factors outlined in the Perfect Storm model of poorly timed and insufficient sleep in adolescents proposed by Carskadon (2011a). Personal characteristics or contextual factors, such as being a boarder or a day scholar, attending a public or private school as well sex differences, accompanied by lifestyle factors such as the consumption of caffeine and usage of electrical devices may have interacted and influenced bed and wake times, resulting in what has been termed “a Perfect Storm of insufficient and inappropriately-timed sleep” in this cohort. Conclusion: The current study provided new insight into the sleep-wake behaviour of late adolescents in Makhanda, Eastern Cape of South Africa. More research is encouraged in the South African context. This knowledge can be used to implement contextually appropriate sleep hygiene education programs in the school curriculum and on an individual level. Furthermore, the results point to the fact that early school start times, in concert with other lifestyle and personal factors may be contributing to insufficient sleep in this group. These results, therefore, highlight the need for schools in this context to consider interventions such as delaying school start times to possibly improve sleep in this context. , Thesis (MSc) -- Faculty of Science, Human Kinetics and Ergonomics, 2021
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- Date Issued: 2021-10-29