An analysis of ways in which the South African tax system could be simplified
- Authors: Young, Gail Jeni
- Date: 2021-04
- Subjects: Taxation -- Law and legislation -- South Africa , Income tax -- Law and legislation -- South Africa , South African Revenue Service , Tax administration and procedure -- South Africa , Tax accounting -- South Africa
- Language: English
- Type: thesis , text , Masters , MCom
- Identifier: http://hdl.handle.net/10962/178235 , vital:42923
- Description: It has been said that the fundamental paradox of tax simplification is that, despite consensus, almost every year tax rules become more complex. This thesis considers tax simplification measures which have been implemented internationally, in order to provide a basis for an analysis of ways in which the South African tax system could be simplified. A doctrinal methodology is applied, and an analysis is carried out of possible tax simplification measures, based on the commentary of experts in the field of tax law. Simplification measures adopted in the United Kingdom, Australia, the United States of America, Egypt, and certain European countries are discussed, together with their possible adoption in South Africa. Tax simplification has a broad scope. This research identifies four areas in which the South African tax system could simplified: the simplification of tax legislation, addressing the role of accounting in the simplification process, reducing the number of taxes currently levied, and finally addressing the complexities evident in the SARS e-filing system. This thesis illustrates several measures which could be used to address the current areas of complexity. Re-writing tax legislation to assist the understanding of taxpayers is suggested. An increase in the inclusion rate for individuals of capital gains in taxable income from 40% to 60% is suggested, to compensate for the loss of revenue due to the recommended repeal of donations tax and estate duty. Aligning tax legislation with accounting standards is identified as a possible area for simplification, as there are many similarities between the two systems. To address the usability of SARS’ e-filing platform, suggestions are made regarding the further pre-population of returns, introducing e-invoicing and providing a “sandbox” function that taxpayers could use to familiarise themselves with how e-filing works. This research highlights tax simplification as a process that needs to be prioritized in order to achieve the associated benefits. , Thesis (MCom) -- Faculty of Commerce, Accounting, 2021
- Full Text:
- Date Issued: 2021-04
- Authors: Young, Gail Jeni
- Date: 2021-04
- Subjects: Taxation -- Law and legislation -- South Africa , Income tax -- Law and legislation -- South Africa , South African Revenue Service , Tax administration and procedure -- South Africa , Tax accounting -- South Africa
- Language: English
- Type: thesis , text , Masters , MCom
- Identifier: http://hdl.handle.net/10962/178235 , vital:42923
- Description: It has been said that the fundamental paradox of tax simplification is that, despite consensus, almost every year tax rules become more complex. This thesis considers tax simplification measures which have been implemented internationally, in order to provide a basis for an analysis of ways in which the South African tax system could be simplified. A doctrinal methodology is applied, and an analysis is carried out of possible tax simplification measures, based on the commentary of experts in the field of tax law. Simplification measures adopted in the United Kingdom, Australia, the United States of America, Egypt, and certain European countries are discussed, together with their possible adoption in South Africa. Tax simplification has a broad scope. This research identifies four areas in which the South African tax system could simplified: the simplification of tax legislation, addressing the role of accounting in the simplification process, reducing the number of taxes currently levied, and finally addressing the complexities evident in the SARS e-filing system. This thesis illustrates several measures which could be used to address the current areas of complexity. Re-writing tax legislation to assist the understanding of taxpayers is suggested. An increase in the inclusion rate for individuals of capital gains in taxable income from 40% to 60% is suggested, to compensate for the loss of revenue due to the recommended repeal of donations tax and estate duty. Aligning tax legislation with accounting standards is identified as a possible area for simplification, as there are many similarities between the two systems. To address the usability of SARS’ e-filing platform, suggestions are made regarding the further pre-population of returns, introducing e-invoicing and providing a “sandbox” function that taxpayers could use to familiarise themselves with how e-filing works. This research highlights tax simplification as a process that needs to be prioritized in order to achieve the associated benefits. , Thesis (MCom) -- Faculty of Commerce, Accounting, 2021
- Full Text:
- Date Issued: 2021-04
The effect of plant-derived dietary protein sources on cultured abalone Haliotis midae (L. 1758) digestive physiology
- Authors: Wright, Jason Geoffrey
- Date: 2021-04
- Subjects: Haliotis midae -- South Africa , Haliotis midae -- Nutrition -- South Africa , Haliotis midae -- Physiology -- South Africa , Haliotis midae -- South Africa -- Growth , Haliotis midae -- Digestive organs , Abalone culture -- South Africa , Plant proteins as feed
- Language: English
- Type: thesis , text , Masters , MSc
- Identifier: http://hdl.handle.net/10962/176803 , vital:42760
- Description: The growth and feed conversion ratio of farmed abalone Haliotis midae (L. 1758) fed a formulated diet varies in feeds with different protein sources. To better understand this, the effect that various combinations of dietary soybean meal (SBM), sunflower meal (SFM) and fishmeal (FM) had on the digestive efficiency of farmed H. midae when included in a formulated feed, were assessed. The aim of this study was to investigate the effect that plant-based proteins had on abalone digestion and gut-bacterial profile of cultured adult abalone when combined with fishmeal. This was done by analysing the chymotrypsin (protease) and cellulase (carbohydrase) digestive enzyme activities from whole-gut sections of farmed abalone that were fed one of four diets for 12 months: FM-only, SBM-only, fishmeal and soybean meal (FM-SBM), and fishmeal and sunflower meal (FM-SFM). There were significant interactions between the diets, sampling date, and sex of the abalone, which had an influence on the cellulase activities in the digestive tracts of the animals. Those fed the SBM diet had the highest cellulase activity by the end of the sampling period (ANOVA; df = 9; F = 2.9; P = 0.005). The significant interactions between diet and sampling date influenced the chymotrypsin activities of abalone. Animals fed the FM diet had the highest activity of chymotrypsin for most of the sampling period (ANOVA; df = 9; F = 2.5; P = 0.01). Therefore, diet did have an impact on the cellulase and chymotrypsin activities of abalone fed either combination diets (FM-SBM; FM-SFM) or single protein diets (FM; SBM). The presence of plant material such as cellulose fibres in the diets containing plant proteins may have influenced the cellulase activity levels of each treatment as it would have stimulated endogenous and exogenous cellulase production. However, treatments with the highest crude fibre content, SBM and FM-SFM, resulted in differing activities. The activity levels of chymotrypsin may have been impacted by the protein type, presence of protein inhibitors and temporal changes in utilisation. Abalone fed the FM diet exhibited the highest chymotrypsin activities on sampling day 182, which was in summer. Animals fed the treatment diets containing fishmeal also developed their reproductive tissues, and may explain the low chymotrypsin activities in abalone fed SBM-only. Additionally, the presence of allergenic compounds would have influenced enzyme activity, as they would have negatively affected the nutrient utilisation and absorptive capacity. Fluctuations in water temperature may have had an effect on enzyme activity, as activities were highest during summer, when seawater temperatures are most variable. A change to lowered water temperatures are known to trigger the growth of digestive epithelial tissue in abalone to allow for increased enzyme secretions and nutrient absorption (Schaeffer et al. 2013). The effect that plant protein inclusion in abalone diets had on the gut-microbiota was revealed by analysing the differences in gut-bacterial community profiles, through the use of metagenomic sequencing. The relative abundance of the phylum Verrucomicrobia, class Verrcomicrobiae and the genus Rubritalea were highest in the SBM diet. These bacterial groups were also influenced by the plant material from soybean meal, as hydrolysed cellulose is broken down by cellulases, and allowed for the proliferation of Rubritalea bacteria due to them using cellobiose as an energy source. The presence of Bacteroidetes was due to the phyla having bacterial species that can breakdown proteins and species that can break down carbohydrates. The animal protein present in the composition of the FM diet had a positive influence on proteolytic Bacteroidetes growth. The high levels of cellulose from the plant fibres in the soybean meal-only diet (SBM) promoted growth of saccharolytic Bacteroidetes. Tenericutes bacteria’s prominence was due to the higher plant fibres from the soybean meal as some Mycoplasma are known to degrade polysaccharides. Therefore, exposure to formulated feeds with high levels of these plant materials would allow for high proliferation. The thesis established that plant-derived dietary proteins in formulated feeds result in an effect on digestive enzyme activity and a difference in the community structure of gut bacteria in H. midae abalone. The results from the current research highlight the importance of studying abalone gut physiology when investigating the impacts of formulated feed composition, and can be used as an additional factor when determining the efficacy of a dietary component. Further research on the gut-bacterial groups and different digestive enzymes of H. midae abalone is encouraged, in order to create a holistic view on their response to dietary plant proteins inclusion in formulated feeds, thus reducing the need for fishmeal protein. , Thesis (MSc)-- Rhodes University, Faculty of Science, Department of Ichthyology and Fisheries Science, 2021
- Full Text:
- Date Issued: 2021-04
- Authors: Wright, Jason Geoffrey
- Date: 2021-04
- Subjects: Haliotis midae -- South Africa , Haliotis midae -- Nutrition -- South Africa , Haliotis midae -- Physiology -- South Africa , Haliotis midae -- South Africa -- Growth , Haliotis midae -- Digestive organs , Abalone culture -- South Africa , Plant proteins as feed
- Language: English
- Type: thesis , text , Masters , MSc
- Identifier: http://hdl.handle.net/10962/176803 , vital:42760
- Description: The growth and feed conversion ratio of farmed abalone Haliotis midae (L. 1758) fed a formulated diet varies in feeds with different protein sources. To better understand this, the effect that various combinations of dietary soybean meal (SBM), sunflower meal (SFM) and fishmeal (FM) had on the digestive efficiency of farmed H. midae when included in a formulated feed, were assessed. The aim of this study was to investigate the effect that plant-based proteins had on abalone digestion and gut-bacterial profile of cultured adult abalone when combined with fishmeal. This was done by analysing the chymotrypsin (protease) and cellulase (carbohydrase) digestive enzyme activities from whole-gut sections of farmed abalone that were fed one of four diets for 12 months: FM-only, SBM-only, fishmeal and soybean meal (FM-SBM), and fishmeal and sunflower meal (FM-SFM). There were significant interactions between the diets, sampling date, and sex of the abalone, which had an influence on the cellulase activities in the digestive tracts of the animals. Those fed the SBM diet had the highest cellulase activity by the end of the sampling period (ANOVA; df = 9; F = 2.9; P = 0.005). The significant interactions between diet and sampling date influenced the chymotrypsin activities of abalone. Animals fed the FM diet had the highest activity of chymotrypsin for most of the sampling period (ANOVA; df = 9; F = 2.5; P = 0.01). Therefore, diet did have an impact on the cellulase and chymotrypsin activities of abalone fed either combination diets (FM-SBM; FM-SFM) or single protein diets (FM; SBM). The presence of plant material such as cellulose fibres in the diets containing plant proteins may have influenced the cellulase activity levels of each treatment as it would have stimulated endogenous and exogenous cellulase production. However, treatments with the highest crude fibre content, SBM and FM-SFM, resulted in differing activities. The activity levels of chymotrypsin may have been impacted by the protein type, presence of protein inhibitors and temporal changes in utilisation. Abalone fed the FM diet exhibited the highest chymotrypsin activities on sampling day 182, which was in summer. Animals fed the treatment diets containing fishmeal also developed their reproductive tissues, and may explain the low chymotrypsin activities in abalone fed SBM-only. Additionally, the presence of allergenic compounds would have influenced enzyme activity, as they would have negatively affected the nutrient utilisation and absorptive capacity. Fluctuations in water temperature may have had an effect on enzyme activity, as activities were highest during summer, when seawater temperatures are most variable. A change to lowered water temperatures are known to trigger the growth of digestive epithelial tissue in abalone to allow for increased enzyme secretions and nutrient absorption (Schaeffer et al. 2013). The effect that plant protein inclusion in abalone diets had on the gut-microbiota was revealed by analysing the differences in gut-bacterial community profiles, through the use of metagenomic sequencing. The relative abundance of the phylum Verrucomicrobia, class Verrcomicrobiae and the genus Rubritalea were highest in the SBM diet. These bacterial groups were also influenced by the plant material from soybean meal, as hydrolysed cellulose is broken down by cellulases, and allowed for the proliferation of Rubritalea bacteria due to them using cellobiose as an energy source. The presence of Bacteroidetes was due to the phyla having bacterial species that can breakdown proteins and species that can break down carbohydrates. The animal protein present in the composition of the FM diet had a positive influence on proteolytic Bacteroidetes growth. The high levels of cellulose from the plant fibres in the soybean meal-only diet (SBM) promoted growth of saccharolytic Bacteroidetes. Tenericutes bacteria’s prominence was due to the higher plant fibres from the soybean meal as some Mycoplasma are known to degrade polysaccharides. Therefore, exposure to formulated feeds with high levels of these plant materials would allow for high proliferation. The thesis established that plant-derived dietary proteins in formulated feeds result in an effect on digestive enzyme activity and a difference in the community structure of gut bacteria in H. midae abalone. The results from the current research highlight the importance of studying abalone gut physiology when investigating the impacts of formulated feed composition, and can be used as an additional factor when determining the efficacy of a dietary component. Further research on the gut-bacterial groups and different digestive enzymes of H. midae abalone is encouraged, in order to create a holistic view on their response to dietary plant proteins inclusion in formulated feeds, thus reducing the need for fishmeal protein. , Thesis (MSc)-- Rhodes University, Faculty of Science, Department of Ichthyology and Fisheries Science, 2021
- Full Text:
- Date Issued: 2021-04
How selected Grade 7 participants develop conceptual understanding in solving algebraic problems as a result of participating in a screencast intervention
- Authors: Wienekus, George Renier
- Date: 2021-04
- Subjects: Algebra -- Study and teaching -- South Africa , Mathematics -- Study and teaching (Elementary) -- South Africa , Problem solving in children , Algebra -- Ability testing , Algebra -- Computer-assisted instruction
- Language: English
- Type: thesis , text , Masters , MEd
- Identifier: http://hdl.handle.net/10962/176833 , vital:42763
- Description: This research project is an interventionist case study, oriented in the interpretive paradigm, which aims to investigate how selected Grade 7 participants develop conceptual understanding in solving algebraic problems as a result of participating in screencast interventions. The aim of my screencast intervention programme, which lies at the heart of this study, is to develop practices, inter alia, of how such devices and software may be “used to develop conceptual rather than procedural or decorative knowledge” (Larkin & Calder, 2015:1) in solving linear equations. The planned intervention was delivered in the form of a series of screencasts: these take the form of audio-video lessons with an emphasis on the visual impact, and were recorded using an application called Explain Everything. The screencast interventions were delivered via Google Classroom and included animations supported by such conceptual explanations of early algebra as are relevant to Grade 7 students, and in line with the South African Curriculum and Assessment Policy Statements - Department of Education, 2011. The fundamental components of an early algebraic equation that would be relevant to a Grade 7 student were considered and used to develop an analytic framework. This was based on a taxonomy designed according to four identified “clusters” in order to analyse the workings of the purposefully selected Grade 7 participants who were video recorded and questioned in a talk-aloud interview while they completed a post-intervention pencil-and-paper test. What emerges from this research project is that there is a significant need for specific and concentrated technology-based techniques, such as the interventions undertaken here, and that exploration and development in the field could benefit the delivery of a pedagogy for algebra. The pedagogical methods implemented and studied in the form of screencasts proved to be successful and were well received by the learners particularly in relation to the conceptualisation of “symbol sense” and transformation in early algebra. The structure and design of the screencast interventions were important in supporting the acquisition of these concepts and were demonstrated to be worthwhile tools for an epistemological application in a classroom or teaching context. , Thesis (MEd) -- Rhodes University, Faculty of Education, Education, 2021
- Full Text:
- Date Issued: 2021-04
- Authors: Wienekus, George Renier
- Date: 2021-04
- Subjects: Algebra -- Study and teaching -- South Africa , Mathematics -- Study and teaching (Elementary) -- South Africa , Problem solving in children , Algebra -- Ability testing , Algebra -- Computer-assisted instruction
- Language: English
- Type: thesis , text , Masters , MEd
- Identifier: http://hdl.handle.net/10962/176833 , vital:42763
- Description: This research project is an interventionist case study, oriented in the interpretive paradigm, which aims to investigate how selected Grade 7 participants develop conceptual understanding in solving algebraic problems as a result of participating in screencast interventions. The aim of my screencast intervention programme, which lies at the heart of this study, is to develop practices, inter alia, of how such devices and software may be “used to develop conceptual rather than procedural or decorative knowledge” (Larkin & Calder, 2015:1) in solving linear equations. The planned intervention was delivered in the form of a series of screencasts: these take the form of audio-video lessons with an emphasis on the visual impact, and were recorded using an application called Explain Everything. The screencast interventions were delivered via Google Classroom and included animations supported by such conceptual explanations of early algebra as are relevant to Grade 7 students, and in line with the South African Curriculum and Assessment Policy Statements - Department of Education, 2011. The fundamental components of an early algebraic equation that would be relevant to a Grade 7 student were considered and used to develop an analytic framework. This was based on a taxonomy designed according to four identified “clusters” in order to analyse the workings of the purposefully selected Grade 7 participants who were video recorded and questioned in a talk-aloud interview while they completed a post-intervention pencil-and-paper test. What emerges from this research project is that there is a significant need for specific and concentrated technology-based techniques, such as the interventions undertaken here, and that exploration and development in the field could benefit the delivery of a pedagogy for algebra. The pedagogical methods implemented and studied in the form of screencasts proved to be successful and were well received by the learners particularly in relation to the conceptualisation of “symbol sense” and transformation in early algebra. The structure and design of the screencast interventions were important in supporting the acquisition of these concepts and were demonstrated to be worthwhile tools for an epistemological application in a classroom or teaching context. , Thesis (MEd) -- Rhodes University, Faculty of Education, Education, 2021
- Full Text:
- Date Issued: 2021-04
Development of a protocol for extracting and quantifying the concentration of thiafentanil in blesbok (Damaliscus pygargus phillipsi) matrices 72-74 hours post administration
- Authors: Webber, Judith Tracy
- Date: 2020
- Subjects: Uncatalogued
- Language: English
- Type: thesis , text , Masters , MSc
- Identifier: http://hdl.handle.net/10962/164738 , vital:41159
- Description: Thesis (MSc)--Rhodes University, Faculty of Science, Chemistry, 2020
- Full Text:
- Date Issued: 2020
- Authors: Webber, Judith Tracy
- Date: 2020
- Subjects: Uncatalogued
- Language: English
- Type: thesis , text , Masters , MSc
- Identifier: http://hdl.handle.net/10962/164738 , vital:41159
- Description: Thesis (MSc)--Rhodes University, Faculty of Science, Chemistry, 2020
- Full Text:
- Date Issued: 2020
Effects of organic and inorganic pollutants on the quality of river water and evaluation of possible negative effects on human health in the Eastern Cape Province
- Authors: Vumazonke, Sesethu
- Date: 2020-04
- Subjects: Uncatalogued
- Language: English
- Type: thesis , text , Masters , MSc (Pharmacy)
- Identifier: http://hdl.handle.net/10962/164727 , vital:41158
- Description: Thesis (MSc)--Rhodes University, Faculty of Pharmacy, Pharmaceutics, 2020
- Full Text:
- Date Issued: 2020-04
- Authors: Vumazonke, Sesethu
- Date: 2020-04
- Subjects: Uncatalogued
- Language: English
- Type: thesis , text , Masters , MSc (Pharmacy)
- Identifier: http://hdl.handle.net/10962/164727 , vital:41158
- Description: Thesis (MSc)--Rhodes University, Faculty of Pharmacy, Pharmaceutics, 2020
- Full Text:
- Date Issued: 2020-04
Hierdie keer gaan nie maklik wees nie
- Authors: Visser, Deon Claudius
- Date: 2021-04
- Subjects: Creative writing (Higher education) -- South Africa , Diaries -- Authorship , Short stories, Afrikaans -- 21st century , Afrikaans fiction -- 21st century , Afrikaans fiction -- History and criticism
- Language: Afrikaans
- Type: thesis , text , Masters , MA
- Identifier: http://hdl.handle.net/10962/178317 , vital:42929
- Description: My tesis bestaan uit twee versamelings van prosa wat verwant en in noue verband met mekaar tree. Die prosa is fragmentaries en kort maar verbind met ‟n oorkoepelende storie wat in beide Afrikaans en Engels voorgelê word. Die Afrikaanse deel van my tesis ondersoek die verlede, en die Engels die toekoms. My algemene bron van inspirasie vir die struktuur en voorlegging van die tesis word verkry vanaf die klassieke raamverteller konvensie soos gebruik in One Thousand and One Nights, hierdie konvensie maak gebruik van raamfragmente wat binne ‟n groter geheel gevind kan word. Dit is juis hierdie komplekse struktuur wat dit moontlik maak om tyd, hede en verlede asook die toekoms, te kan ondersoek en uit te beeld. Verder maak dit dit ook moontlik om gekoppelde herinneringe, gedagteneigings, en fantasieverhale te kan gebruik as die dryfkrag van die oorkoepelende storie. Met betrekking tot kontemporêre fiksie vind ek die meeste aanklank en invloed by Sandra Cisneros se boek House on Mango Street. Ek het by hierdie verhaal geleer hoe om vignette en kortverhale onafhanklik maar met ‟n motief-verbinding aan mekaar te koppel. Tematies gesproke handel my tesis oor herinneringe, nostalgie, familieverhoudings, die dood asook afsluiting en aanbeweging. In terme van hierdie temas vind ek dat Nathan Trantraal se Chokers en Survivors, en Noudat Slapende Honde deur Ronelda S. Kamfer my die meeste insae gee oor die verhouding tussen Afrikaans en Engels in die literatuur. Verder is Loftus Marais se taalgebruik en die vermenging van taal in Staan in die Algemeen Nader aan Vensters ook insiggewend. , Thesis (MA) -- Faculty of Humanities, School of Languages and Literatures, 2021
- Full Text:
- Date Issued: 2021-04
- Authors: Visser, Deon Claudius
- Date: 2021-04
- Subjects: Creative writing (Higher education) -- South Africa , Diaries -- Authorship , Short stories, Afrikaans -- 21st century , Afrikaans fiction -- 21st century , Afrikaans fiction -- History and criticism
- Language: Afrikaans
- Type: thesis , text , Masters , MA
- Identifier: http://hdl.handle.net/10962/178317 , vital:42929
- Description: My tesis bestaan uit twee versamelings van prosa wat verwant en in noue verband met mekaar tree. Die prosa is fragmentaries en kort maar verbind met ‟n oorkoepelende storie wat in beide Afrikaans en Engels voorgelê word. Die Afrikaanse deel van my tesis ondersoek die verlede, en die Engels die toekoms. My algemene bron van inspirasie vir die struktuur en voorlegging van die tesis word verkry vanaf die klassieke raamverteller konvensie soos gebruik in One Thousand and One Nights, hierdie konvensie maak gebruik van raamfragmente wat binne ‟n groter geheel gevind kan word. Dit is juis hierdie komplekse struktuur wat dit moontlik maak om tyd, hede en verlede asook die toekoms, te kan ondersoek en uit te beeld. Verder maak dit dit ook moontlik om gekoppelde herinneringe, gedagteneigings, en fantasieverhale te kan gebruik as die dryfkrag van die oorkoepelende storie. Met betrekking tot kontemporêre fiksie vind ek die meeste aanklank en invloed by Sandra Cisneros se boek House on Mango Street. Ek het by hierdie verhaal geleer hoe om vignette en kortverhale onafhanklik maar met ‟n motief-verbinding aan mekaar te koppel. Tematies gesproke handel my tesis oor herinneringe, nostalgie, familieverhoudings, die dood asook afsluiting en aanbeweging. In terme van hierdie temas vind ek dat Nathan Trantraal se Chokers en Survivors, en Noudat Slapende Honde deur Ronelda S. Kamfer my die meeste insae gee oor die verhouding tussen Afrikaans en Engels in die literatuur. Verder is Loftus Marais se taalgebruik en die vermenging van taal in Staan in die Algemeen Nader aan Vensters ook insiggewend. , Thesis (MA) -- Faculty of Humanities, School of Languages and Literatures, 2021
- Full Text:
- Date Issued: 2021-04
Healthcare issues in disaster management : preparedness in the pharmacy profession
- Authors: Vhiriri, Eunice Paidamoyo
- Date: 2021-04
- Subjects: To be added
- Language: English
- Type: thesis , text , Masters , MSc
- Identifier: http://hdl.handle.net/10962/178591 , vital:42953
- Description: Access restricted until April 2023. , Thesis (MSc) -- Faculty of Pharmacy, Pharmacy, 2021
- Full Text:
- Date Issued: 2021-04
- Authors: Vhiriri, Eunice Paidamoyo
- Date: 2021-04
- Subjects: To be added
- Language: English
- Type: thesis , text , Masters , MSc
- Identifier: http://hdl.handle.net/10962/178591 , vital:42953
- Description: Access restricted until April 2023. , Thesis (MSc) -- Faculty of Pharmacy, Pharmacy, 2021
- Full Text:
- Date Issued: 2021-04
Livelihood implications of a possible Ramsar declaration of the Swartkops estuary, Eastern Cape, South Africa
- Authors: Vembo, Glen Muchengeti
- Date: 2020
- Subjects: Uncatalogued
- Language: English
- Type: thesis , text , Masters , MSc
- Identifier: http://hdl.handle.net/10962/164715 , vital:41157
- Description: Thesis (MSc)--Rhodes University, Faculty of Science, Environmental Science, 2020
- Full Text:
- Date Issued: 2020
- Authors: Vembo, Glen Muchengeti
- Date: 2020
- Subjects: Uncatalogued
- Language: English
- Type: thesis , text , Masters , MSc
- Identifier: http://hdl.handle.net/10962/164715 , vital:41157
- Description: Thesis (MSc)--Rhodes University, Faculty of Science, Environmental Science, 2020
- Full Text:
- Date Issued: 2020
An assessment of the wild cyclopia subternata (vleitee) resource
- Authors: Van der Walt, Wouter
- Date: 2021-04
- Subjects: Legumes -- South Africa , Fynbos -- South Africa , Fynbos ecology -- South Africa , Fynbos -- Harvesting -- South Africa , Biodiversity conservation -- South Africa , Traditional ecological knowledge -- South Africa , Wild Cyclopia Subternata (Vleitee) , Honeybush tea industry
- Language: English
- Type: thesis , text , Masters , MSc
- Identifier: http://hdl.handle.net/10962/176874 , vital:42767
- Description: Cyclopia spp. is used for the production of Honeybush tea, an herbal tea which is used in many cases as a substitute for rooibos tea. The wild harvesting of this fynbos plant still brings in up to 85% of the annual crop and as such needs to be carefully monitored in order to avoid over harvesting and the destruction of biodiversity within the Eastern and Western Cape mountain regions of Southern Africa. Due to the concerns of overharvesting and unsuitable use of the wild resource issues of supply security have been raised. There is a lack of formal knowledge relating to the plant, its harvesting, the industry and its economic potential. This study aimed to amend this scarcity by contributing to the knowledge of C. subternata as a wild harvested plant, the physical environment favoured by C. subternata, sustainable use through harvesting of the wild plant and harvesting methods specific to this honeybush species. The research concludes by presenting a guideline for best harvest practices of the wild C. subternata plant. , Thesis (MSc) -- Faculty of Science, Department of Geography, 2021
- Full Text:
- Date Issued: 2021-04
- Authors: Van der Walt, Wouter
- Date: 2021-04
- Subjects: Legumes -- South Africa , Fynbos -- South Africa , Fynbos ecology -- South Africa , Fynbos -- Harvesting -- South Africa , Biodiversity conservation -- South Africa , Traditional ecological knowledge -- South Africa , Wild Cyclopia Subternata (Vleitee) , Honeybush tea industry
- Language: English
- Type: thesis , text , Masters , MSc
- Identifier: http://hdl.handle.net/10962/176874 , vital:42767
- Description: Cyclopia spp. is used for the production of Honeybush tea, an herbal tea which is used in many cases as a substitute for rooibos tea. The wild harvesting of this fynbos plant still brings in up to 85% of the annual crop and as such needs to be carefully monitored in order to avoid over harvesting and the destruction of biodiversity within the Eastern and Western Cape mountain regions of Southern Africa. Due to the concerns of overharvesting and unsuitable use of the wild resource issues of supply security have been raised. There is a lack of formal knowledge relating to the plant, its harvesting, the industry and its economic potential. This study aimed to amend this scarcity by contributing to the knowledge of C. subternata as a wild harvested plant, the physical environment favoured by C. subternata, sustainable use through harvesting of the wild plant and harvesting methods specific to this honeybush species. The research concludes by presenting a guideline for best harvest practices of the wild C. subternata plant. , Thesis (MSc) -- Faculty of Science, Department of Geography, 2021
- Full Text:
- Date Issued: 2021-04
Hop as an anti-cancer drug target
- Vaaltyn, Michaelone Chantelle
- Authors: Vaaltyn, Michaelone Chantelle
- Date: 2020
- Subjects: Uncatalogued
- Language: English
- Type: thesis , text , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/164704 , vital:41156 , doi:10.21504/10962/164704
- Description: Thesis (PhD)--Rhodes University, Biochemistry and Microbiology, 2020
- Full Text:
- Date Issued: 2020
- Authors: Vaaltyn, Michaelone Chantelle
- Date: 2020
- Subjects: Uncatalogued
- Language: English
- Type: thesis , text , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/164704 , vital:41156 , doi:10.21504/10962/164704
- Description: Thesis (PhD)--Rhodes University, Biochemistry and Microbiology, 2020
- Full Text:
- Date Issued: 2020
Multiplexed Mass Spectrometry: Single, On-Bead, Detection Analysis Using MALDI-TOF MS
- Authors: Twala, Busisiwe Victoria
- Date: 2020
- Subjects: Uncatalogued
- Language: English
- Type: thesis , text , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/164693 , vital:41155 , doi:10.21504/10962/164693
- Description: Thesis (PhD)--Rhodes University, Biochemistry and Microbiology, 2020
- Full Text:
- Date Issued: 2020
- Authors: Twala, Busisiwe Victoria
- Date: 2020
- Subjects: Uncatalogued
- Language: English
- Type: thesis , text , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/164693 , vital:41155 , doi:10.21504/10962/164693
- Description: Thesis (PhD)--Rhodes University, Biochemistry and Microbiology, 2020
- Full Text:
- Date Issued: 2020
A narrative study of students’ and staff’s experiences of living with HIV and AIDS at Rhodes University
- Authors: Tsope, Lindiwe
- Date: 2021-04
- Subjects: AIDS (Disease) South Africa Makhanda , HIV infections South Africa Makhanda , College students Health and hygiene South Africa Makhanda , Universities and colleges South Africa Makhanda Employees Health and hygiene , Stigma (Social psychology) , AIDS (Disease) Social aspects South Africa Makhanda , HIV infections Social aspects South Africa Makhanda , AIDS (Disease) Psychological aspects , HIV infections Psychological aspects , Health counseling South Africa Makhanda , Discourse analysis, Narrative
- Language: English
- Type: thesis , text , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/176894 , vital:42769 , 10.21504/10962/176894
- Description: A narrative study of students’ and staff’s experiences of living with HIV and AIDS at Rhodes University Research on HIV and AIDS in university settings, especially research exploring the experience of living with the disease, has been minimal. As a response to the knowledge and research gaps, this thesis is a qualitative study involving students and staff living with HIV (LWH) and accessing treatment (ART) at the Rhodes University Health Care Centre. This study explored the personal and social symbolisms as well as meanings attached to living with HIV, through in-depth interviews with ten students and staff living with HIV, all purposively sampled and recruited through the Rhodes University Health Care Centre. Using social constructionism, symbolic interactionism and the theory of biographical disruption, the narratives revealed a positive and inspirational side of living with HIV and AIDS – especially emphasizing that PLWHA do not have to surrender to the deadly narrative of the disease. It became evident that stigma, both internal and external, largely influences illness narratives. Furthermore, the study revealed the social reconstruction of life narratives both in order to understand the illness in terms of past social experiences and to reaffirm the impression that life has a course and the self has a purpose. All participants found that accessing treatment from the Rhodes University Health Care Centre positively influenced their experiences of adherence and reconstruction of narratives. The study indicates that HIV-related interventions in place at the university need to pay more attention to the psychosocial needs of PLWH, involvement of PWLH, as well as keeping up with the continuously changing global HIV narrative. The study argues for more attention to in-depth experiences and personal narratives in HIV and AIDS, and PLWHA education at Rhodes University. , Thesis (PhD) -- Humanities, Department of Sociology, 2021
- Full Text:
- Date Issued: 2021-04
- Authors: Tsope, Lindiwe
- Date: 2021-04
- Subjects: AIDS (Disease) South Africa Makhanda , HIV infections South Africa Makhanda , College students Health and hygiene South Africa Makhanda , Universities and colleges South Africa Makhanda Employees Health and hygiene , Stigma (Social psychology) , AIDS (Disease) Social aspects South Africa Makhanda , HIV infections Social aspects South Africa Makhanda , AIDS (Disease) Psychological aspects , HIV infections Psychological aspects , Health counseling South Africa Makhanda , Discourse analysis, Narrative
- Language: English
- Type: thesis , text , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/176894 , vital:42769 , 10.21504/10962/176894
- Description: A narrative study of students’ and staff’s experiences of living with HIV and AIDS at Rhodes University Research on HIV and AIDS in university settings, especially research exploring the experience of living with the disease, has been minimal. As a response to the knowledge and research gaps, this thesis is a qualitative study involving students and staff living with HIV (LWH) and accessing treatment (ART) at the Rhodes University Health Care Centre. This study explored the personal and social symbolisms as well as meanings attached to living with HIV, through in-depth interviews with ten students and staff living with HIV, all purposively sampled and recruited through the Rhodes University Health Care Centre. Using social constructionism, symbolic interactionism and the theory of biographical disruption, the narratives revealed a positive and inspirational side of living with HIV and AIDS – especially emphasizing that PLWHA do not have to surrender to the deadly narrative of the disease. It became evident that stigma, both internal and external, largely influences illness narratives. Furthermore, the study revealed the social reconstruction of life narratives both in order to understand the illness in terms of past social experiences and to reaffirm the impression that life has a course and the self has a purpose. All participants found that accessing treatment from the Rhodes University Health Care Centre positively influenced their experiences of adherence and reconstruction of narratives. The study indicates that HIV-related interventions in place at the university need to pay more attention to the psychosocial needs of PLWH, involvement of PWLH, as well as keeping up with the continuously changing global HIV narrative. The study argues for more attention to in-depth experiences and personal narratives in HIV and AIDS, and PLWHA education at Rhodes University. , Thesis (PhD) -- Humanities, Department of Sociology, 2021
- Full Text:
- Date Issued: 2021-04
The development of an ionospheric storm-time index for the South African region
- Authors: Tshisaphungo, Mpho
- Date: 2021-04
- Subjects: Ionospheric storms -- South Africa , Global Positioning System , Neural networks (Computer science) , Regression analysis , Ionosondes , Auroral electrojet , Geomagnetic indexes , Magnetic storms -- South Africa
- Language: English
- Type: thesis , text , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/178409 , vital:42937 , 10.21504/10962/178409
- Description: This thesis presents the development of a regional ionospheric storm-time model which forms the foundation of an index to provide a quick view of the ionospheric storm effects over South African mid-latitude region. The model is based on the foF2 measurements from four South African ionosonde stations. The data coverage for the model development over Grahamstown (33.3◦S, 26.5◦E), Hermanus (34.42◦S, 19.22◦E), Louisvale (28.50◦S, 21.20◦E), and Madimbo (22.39◦S, 30.88◦E) is 1996-2016, 2009-2016, 2000-2016, and 2000-2016 respectively. Data from the Global Positioning System (GPS) and radio occultation (RO) technique were used during validation. As the measure of either positive or negative storm effect, the variation of the critical frequency of the F2 layer (foF2) from the monthly median values (denoted as _foF2) is modeled. The modeling of _foF2 is based on only storm time data with the criteria of Dst 6 -50 nT and Kp > 4. The modeling methods used in the study were artificial neural network (ANN), linear regression (LR) and polynomial functions. The approach taken was to first test the modeling techniques on a single station before expanding the study to cover the regional aspect. The single station modeling was developed based on ionosonde data over Grahamstown. The inputs for the model which related to seasonal variation, diurnal variation, geomagnetic activity and solar activity were considered. For the geomagnetic activity, three indices namely; the symmetric disturbance in the horizontal component of the Earth’s magnetic field (SYM − H), the Auroral Electrojet (AE) index and local geomagnetic index A, were included as inputs. The performance of a single station model revealed that, of the three geomagnetic indices, SYM − H index has the largest contribution of 41% and 54% based on ANN and LR techniques respectively. The average correlation coefficients (R) for both ANN and LR models was 0.8, when validated during the selected storms falling within the period of model development. When validated using storms that fall outside the period of model development, the model gave R values of 0.6 and 0.5 for ANN and LR respectively. In addition, the GPS total electron content (TEC) derived measurements were used to estimate foF2 data. This is because there are more GPS receivers than ionosonde locations and the utilisation of this data increases the spatial coverage of the regional model. The estimation of foF2 from GPS TEC was done at GPS-ionosonde co-locations using polynomial functions. The average R values of 0.69 and 0.65 were obtained between actual and derived _foF2 over the co-locations and other GPS stations respectively. Validation of GPS TEC derived foF2 with RO data over regions out of ionospheric pierce points coverage with respect to ionosonde locations gave R greater than 0.9 for the selected storm period of 4-8 August 2011. The regional storm-time model was then developed based on the ANN technique using the four South African ionosonde stations. The maximum and minimum R values of 0.6 and 0.5 were obtained over ionosonde and GPS locations respectively. This model forms the basis towards the regional ionospheric storm-time index. , Thesis (PhD) -- Faculty of Science, Physics and Electronics, 2021
- Full Text:
- Date Issued: 2021-04
- Authors: Tshisaphungo, Mpho
- Date: 2021-04
- Subjects: Ionospheric storms -- South Africa , Global Positioning System , Neural networks (Computer science) , Regression analysis , Ionosondes , Auroral electrojet , Geomagnetic indexes , Magnetic storms -- South Africa
- Language: English
- Type: thesis , text , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/178409 , vital:42937 , 10.21504/10962/178409
- Description: This thesis presents the development of a regional ionospheric storm-time model which forms the foundation of an index to provide a quick view of the ionospheric storm effects over South African mid-latitude region. The model is based on the foF2 measurements from four South African ionosonde stations. The data coverage for the model development over Grahamstown (33.3◦S, 26.5◦E), Hermanus (34.42◦S, 19.22◦E), Louisvale (28.50◦S, 21.20◦E), and Madimbo (22.39◦S, 30.88◦E) is 1996-2016, 2009-2016, 2000-2016, and 2000-2016 respectively. Data from the Global Positioning System (GPS) and radio occultation (RO) technique were used during validation. As the measure of either positive or negative storm effect, the variation of the critical frequency of the F2 layer (foF2) from the monthly median values (denoted as _foF2) is modeled. The modeling of _foF2 is based on only storm time data with the criteria of Dst 6 -50 nT and Kp > 4. The modeling methods used in the study were artificial neural network (ANN), linear regression (LR) and polynomial functions. The approach taken was to first test the modeling techniques on a single station before expanding the study to cover the regional aspect. The single station modeling was developed based on ionosonde data over Grahamstown. The inputs for the model which related to seasonal variation, diurnal variation, geomagnetic activity and solar activity were considered. For the geomagnetic activity, three indices namely; the symmetric disturbance in the horizontal component of the Earth’s magnetic field (SYM − H), the Auroral Electrojet (AE) index and local geomagnetic index A, were included as inputs. The performance of a single station model revealed that, of the three geomagnetic indices, SYM − H index has the largest contribution of 41% and 54% based on ANN and LR techniques respectively. The average correlation coefficients (R) for both ANN and LR models was 0.8, when validated during the selected storms falling within the period of model development. When validated using storms that fall outside the period of model development, the model gave R values of 0.6 and 0.5 for ANN and LR respectively. In addition, the GPS total electron content (TEC) derived measurements were used to estimate foF2 data. This is because there are more GPS receivers than ionosonde locations and the utilisation of this data increases the spatial coverage of the regional model. The estimation of foF2 from GPS TEC was done at GPS-ionosonde co-locations using polynomial functions. The average R values of 0.69 and 0.65 were obtained between actual and derived _foF2 over the co-locations and other GPS stations respectively. Validation of GPS TEC derived foF2 with RO data over regions out of ionospheric pierce points coverage with respect to ionosonde locations gave R greater than 0.9 for the selected storm period of 4-8 August 2011. The regional storm-time model was then developed based on the ANN technique using the four South African ionosonde stations. The maximum and minimum R values of 0.6 and 0.5 were obtained over ionosonde and GPS locations respectively. This model forms the basis towards the regional ionospheric storm-time index. , Thesis (PhD) -- Faculty of Science, Physics and Electronics, 2021
- Full Text:
- Date Issued: 2021-04
Design of pH Sensitive Electrochemical Sensor for Catecholamine Neurotransmitters Detection and the Screening Off of Ascorbic Acid
- Tshenkeng, Keamogetse Tebogo Charlotte
- Authors: Tshenkeng, Keamogetse Tebogo Charlotte
- Date: 2021-10-29
- Subjects: Catecholamines , Electrochemical sensors , Neurotransmitters , Vitamin C , Cobalt , Phthalocyanines , Cobalt (II) tetra-(3-carboxyphenoxy) phthalocyanine (CoTCPhOPc)
- Language: English
- Type: thesis , text
- Identifier: http://hdl.handle.net/10962/176921 , vital:42772
- Description: This study presents the synthesis of cobalt (II) tetra-(3-carboxyphenoxy) phthalocyanine (CoTCPhOPc) through the cyclotetramerization of 4-(3-carboxyphe-noxy)phthalonitrile and its full characterization using Fourier transform infrared (FT-IR) spectroscopy, ultraviolet-visible (UV-vis) spectroscopy, magnetic circular dichroism (MCD) spectroscopy, elemental analysis and mass spectrometry. The CoTCPhOPc was then immobilized onto phenylethylamino (PEA) pre-grafted gold electrode surface, Au-PEA using amide coupling reaction through a reaction with NHS and DCC to obtain Au-PEA-CoTCPhOPc. This yielded pH sensitive thin films due to the terminal carboxylic acid (–COOH) functional groups. Electrochemical and surface characterization was conducted to confirm the modification of the bare Au with PEA thin film (Au-PEA) and amide coupling of CoTCPhOPc (Au-PEA-CoTCPhOPc). The Au-PEA-CoTCPhOPc electrode was shown to possess pH selective properties towards negatively charged [Fe(CN)6]3-/4- and positively charged [Ru(NH3)6]2+/3+ redox probes. Au-PEA-CoTCPhOPc electrode surface enabled the detection of catecholamine neurotransmitters (dopamine, norepinephrine and epinephrine) and the screening off of ascorbic acid by means of pH sensitive functional groups. Bare Au and Au-PEA electrodes exhibited electro-oxidation and electroreduction of catecholamine neuro-transmitters and ascorbic acid at higher potentials compared to Au-PEA-CoTCPhOPc. There was no electro-oxidation or electroreduction of ascorbic acid at Au-PEA-CoTCPhOPc. For Au-PEA-CoTCPhOPc, excellent electrocatalytic oxidation with the limit of detection (LoD) determined using 3σ was found to be 1.32 (0.95), 2.11 (1.78) and 3.08 μM for electro-oxidation and electroreduction (in brackets) of dopamine, norepinephrine and epinephrine respectively. The limit of quantification (LoQ) was determined using 10σ and found to be 4.41 (3.17), 7.02 (5.93) and 10.3 μM electro-oxidation and electroreduction (in brackets) for dopamine, norepinephrine and epinephrine respectively. The Au-PEA-CoTCPhOPc thin film was shown to screen off ascorbic acid as no electrocatalytic oxidation was observed for up to 100.0 μM concentration. , Thesis (MSc) -- Faculty of Science, Department of Chemistry, 2021
- Full Text:
- Date Issued: 2021-10-29
- Authors: Tshenkeng, Keamogetse Tebogo Charlotte
- Date: 2021-10-29
- Subjects: Catecholamines , Electrochemical sensors , Neurotransmitters , Vitamin C , Cobalt , Phthalocyanines , Cobalt (II) tetra-(3-carboxyphenoxy) phthalocyanine (CoTCPhOPc)
- Language: English
- Type: thesis , text
- Identifier: http://hdl.handle.net/10962/176921 , vital:42772
- Description: This study presents the synthesis of cobalt (II) tetra-(3-carboxyphenoxy) phthalocyanine (CoTCPhOPc) through the cyclotetramerization of 4-(3-carboxyphe-noxy)phthalonitrile and its full characterization using Fourier transform infrared (FT-IR) spectroscopy, ultraviolet-visible (UV-vis) spectroscopy, magnetic circular dichroism (MCD) spectroscopy, elemental analysis and mass spectrometry. The CoTCPhOPc was then immobilized onto phenylethylamino (PEA) pre-grafted gold electrode surface, Au-PEA using amide coupling reaction through a reaction with NHS and DCC to obtain Au-PEA-CoTCPhOPc. This yielded pH sensitive thin films due to the terminal carboxylic acid (–COOH) functional groups. Electrochemical and surface characterization was conducted to confirm the modification of the bare Au with PEA thin film (Au-PEA) and amide coupling of CoTCPhOPc (Au-PEA-CoTCPhOPc). The Au-PEA-CoTCPhOPc electrode was shown to possess pH selective properties towards negatively charged [Fe(CN)6]3-/4- and positively charged [Ru(NH3)6]2+/3+ redox probes. Au-PEA-CoTCPhOPc electrode surface enabled the detection of catecholamine neurotransmitters (dopamine, norepinephrine and epinephrine) and the screening off of ascorbic acid by means of pH sensitive functional groups. Bare Au and Au-PEA electrodes exhibited electro-oxidation and electroreduction of catecholamine neuro-transmitters and ascorbic acid at higher potentials compared to Au-PEA-CoTCPhOPc. There was no electro-oxidation or electroreduction of ascorbic acid at Au-PEA-CoTCPhOPc. For Au-PEA-CoTCPhOPc, excellent electrocatalytic oxidation with the limit of detection (LoD) determined using 3σ was found to be 1.32 (0.95), 2.11 (1.78) and 3.08 μM for electro-oxidation and electroreduction (in brackets) of dopamine, norepinephrine and epinephrine respectively. The limit of quantification (LoQ) was determined using 10σ and found to be 4.41 (3.17), 7.02 (5.93) and 10.3 μM electro-oxidation and electroreduction (in brackets) for dopamine, norepinephrine and epinephrine respectively. The Au-PEA-CoTCPhOPc thin film was shown to screen off ascorbic acid as no electrocatalytic oxidation was observed for up to 100.0 μM concentration. , Thesis (MSc) -- Faculty of Science, Department of Chemistry, 2021
- Full Text:
- Date Issued: 2021-10-29
The reproductive performance, demography and spatial ecology of an extralimital white rhinoceros population
- Authors: Truter, Anja
- Date: 2021-04
- Subjects: White rhinoceros -- South Africa -- Eastern Cape , White rhinoceros -- Effect of poaching on -- South Africa -- Eastern Cape , White rhinoceros -- South Africa -- Eastern Cape -- Reproduction , White rhinoceros -- Dispersal -- South Africa -- Eastern Cape , White rhinoceros -- Food -- South Africa -- Eastern Cape , White rhinoceros -- Behavior -- South Africa -- Eastern Cape , Spatial ecology -- South Africa -- Eastern Cape , Animal populations -- South Africa -- Eastern Cape , Endangered species -- South Africa -- Eastern Cape , Spatial behavior in animals -- South Africa -- Eastern Cape , Shamwari Game Reserve (South Africa)
- Language: English
- Type: thesis , text , Master , MSc
- Identifier: http://hdl.handle.net/10962/177975 , vital:42895
- Description: The white rhinoceros (Ceratotherium simum) (hereafter rhino) is under threat of becoming extinct due to continued poaching for its horns. In South Africa and elsewhere in Africa private landowners have, over the last few decades, contributed to the conservation of various species, including rhinos, even in areas where they have not occurred historically (i.e., where they are extralimital). Unfortunately, very few studies have investigated the conservation contribution of extralimital white rhinos on private reserves to the overall meta-population and/or their reproductive performance. The first aim of my study was therefore to determine whether or not the white rhinos introduced to a private game reserve in the Eastern Cape Province in 1992 have been successful from a reproductive perspective. I calculated inter-calving intervals, age at first calving, conception period, sex ratio, fecundity and fertility rates for white rhinos over this 28-year period. The average annual population growth rate for the rhinos was 10%, which is higher than the recommended 5% by the Rhino Management Group. Trends in density-dependent parameters such as age at first calving and inter-calving intervals also indicated that my study population is still well below carrying capacity for white rhinos and is contributing positively to white rhino conservation in South Africa. The second aim of my study was to investigate home range size and vegetation preferences of white rhinos. Home ranges were mostly larger for all age groups compared to rhinos in their native range. Previously cultivated lands (dominated by several grass species) were preferred by all rhino age groups. The rehabilitation of these previous agricultural-based pastures has likely contributed to the successful introduction of the white rhino as an extralimital megaherbivore in the Eastern Cape. I conclude that although extralimital white rhino populations in the Eastern Cape can be successful from a reproductive perspective, their potential impact on the indigenous biodiversity of the region should be a key future research priority. , Thesis (MSc) -- Faculty of Science, Zoology and Entomology, 2021
- Full Text:
- Date Issued: 2021-04
- Authors: Truter, Anja
- Date: 2021-04
- Subjects: White rhinoceros -- South Africa -- Eastern Cape , White rhinoceros -- Effect of poaching on -- South Africa -- Eastern Cape , White rhinoceros -- South Africa -- Eastern Cape -- Reproduction , White rhinoceros -- Dispersal -- South Africa -- Eastern Cape , White rhinoceros -- Food -- South Africa -- Eastern Cape , White rhinoceros -- Behavior -- South Africa -- Eastern Cape , Spatial ecology -- South Africa -- Eastern Cape , Animal populations -- South Africa -- Eastern Cape , Endangered species -- South Africa -- Eastern Cape , Spatial behavior in animals -- South Africa -- Eastern Cape , Shamwari Game Reserve (South Africa)
- Language: English
- Type: thesis , text , Master , MSc
- Identifier: http://hdl.handle.net/10962/177975 , vital:42895
- Description: The white rhinoceros (Ceratotherium simum) (hereafter rhino) is under threat of becoming extinct due to continued poaching for its horns. In South Africa and elsewhere in Africa private landowners have, over the last few decades, contributed to the conservation of various species, including rhinos, even in areas where they have not occurred historically (i.e., where they are extralimital). Unfortunately, very few studies have investigated the conservation contribution of extralimital white rhinos on private reserves to the overall meta-population and/or their reproductive performance. The first aim of my study was therefore to determine whether or not the white rhinos introduced to a private game reserve in the Eastern Cape Province in 1992 have been successful from a reproductive perspective. I calculated inter-calving intervals, age at first calving, conception period, sex ratio, fecundity and fertility rates for white rhinos over this 28-year period. The average annual population growth rate for the rhinos was 10%, which is higher than the recommended 5% by the Rhino Management Group. Trends in density-dependent parameters such as age at first calving and inter-calving intervals also indicated that my study population is still well below carrying capacity for white rhinos and is contributing positively to white rhino conservation in South Africa. The second aim of my study was to investigate home range size and vegetation preferences of white rhinos. Home ranges were mostly larger for all age groups compared to rhinos in their native range. Previously cultivated lands (dominated by several grass species) were preferred by all rhino age groups. The rehabilitation of these previous agricultural-based pastures has likely contributed to the successful introduction of the white rhino as an extralimital megaherbivore in the Eastern Cape. I conclude that although extralimital white rhino populations in the Eastern Cape can be successful from a reproductive perspective, their potential impact on the indigenous biodiversity of the region should be a key future research priority. , Thesis (MSc) -- Faculty of Science, Zoology and Entomology, 2021
- Full Text:
- Date Issued: 2021-04
The effect of various substrate pretreatment methods on the enzymatic degradability of a Eucalyptus sp. – a potential feedstock for producing fermentable sugars
- Authors: Thoresen, Mariska
- Date: 2021-04
- Subjects: To be added
- Language: English
- Type: thesis , text , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/178580 , vital:42952
- Description: Access restricted until April 2022. , Thesis (PhD) -- Faculty of Science, Biochemistry and Microbiology, 2021
- Full Text:
- Date Issued: 2021-04
- Authors: Thoresen, Mariska
- Date: 2021-04
- Subjects: To be added
- Language: English
- Type: thesis , text , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/178580 , vital:42952
- Description: Access restricted until April 2022. , Thesis (PhD) -- Faculty of Science, Biochemistry and Microbiology, 2021
- Full Text:
- Date Issued: 2021-04
Alternative approach to controlling citrus black spot disease
- Authors: Thabede, Jahman Thabo
- Date: 2021-04
- Subjects: To be added
- Language: English
- Type: thesis , text , Masters , MSc
- Identifier: http://hdl.handle.net/10962/178569 , vital:42951
- Description: Access restricted until April 2022. , Thesis (MSc) -- Faculty of Science, Biochemistry and Microbiology, 2021
- Full Text:
- Date Issued: 2021-04
- Authors: Thabede, Jahman Thabo
- Date: 2021-04
- Subjects: To be added
- Language: English
- Type: thesis , text , Masters , MSc
- Identifier: http://hdl.handle.net/10962/178569 , vital:42951
- Description: Access restricted until April 2022. , Thesis (MSc) -- Faculty of Science, Biochemistry and Microbiology, 2021
- Full Text:
- Date Issued: 2021-04
Baculovirus synergism for improved management of false codling moth Thaumatotibia leucotreta Meyr. (Lepidoptera: Tortricidae)
- Authors: Taylor, David Graham
- Date: 2021-04
- Subjects: Baculoviruses , Cryptophlebia leucotreta , Cryptophlebia leucotreta -- Biological control , Biological pest control agents , Citrus -- Diseases and pests , Codling moth , Cryptophlebia peltastica nucleopolyhedrovirus (CrpeNPV)
- Language: English
- Type: thesis , text , Masters , MSc
- Identifier: http://hdl.handle.net/10962/176942 , vital:42774
- Description: Baculoviruses are an environmentally friendly and effective agent for managing lepidopteran pests. This includes the management of Thaumatotibia leucotreta (Meyrick) (Lepidoptera: Tortricidae), a serious pest of citrus in Southern Africa and a major threat to the South African citrus export industry. For more than 15 years, CrleGV-SA- based biopesticides have been used as part of an integrated pest management strategy for the control of T. leucotreta in citrus orchards in South Africa, under the names Cryptogran™ and Cryptex®. While these biopesticides have been effective during this period, there are some areas in which baculovirus use could potentially be improved. Baculoviruses are notoriously slow to kill in comparison to chemical-based pesticides, and lately, pest resistance to baculoviruses has become a major concern with the development of resistance by Cydia pomonella (Linnaeus) (Lepidoptera: Tortricidae) to its granulovirus occurring in the field in Europe. The consistent use of CrleGV-SA for more than 15 years in the field has raised concern that T. leucotreta could develop resistance to this virus, and has made it necessary to alter baculovirus-based management strategies to prevent this from occurring. A second baculovirus, Cryptophlebia peltastica nucleopolyhedrovirus (CrpeNPV), has recently been isolated and was shown to be effective against T. leucotreta. However, the interactions between CrleGV-SA and CrpeNPV are not yet understood and so it is important to test these interactions before both viruses are applied on the same orchards. Not only is it important to know whether these viruses could negatively impact each other, but it is also important to test whether they could interact synergistically. A synergistic interaction could not only provide a potential tool for the management of resistance, but it could also be exploited to improve baculovirus-based management of T. leucotreta. In this study, a stock of CrleGV-SA was purified by glycerol gradient centrifugation from T. leucotreta cadavers, while a stock of CrpeNPV purified from Cryptophlebia peltastica (Meyrick) (Lepidoptera: Tortricidae) cadavers was provided by River Bioscience (Pty) Ltd. These stocks were screened for purity by a multiplex polymerase chain reaction (mPCR) protocol designed to detect CrleGV-SA and CrpeNPV. The occlusion body (OB) density was then calculated using darkfield microscopy and a counting chamber. Both stocks were shown to be pure within the limits of the mPCR protocol, and the CrleGV-SA and CrpeNPV stocks were calculated to contain 3.08 × 1011 OBs/mL and 1.92 × 1011 OBs/mL respectively The first aspect of the interaction between CrleGV-SA and CrpeNPV that was investigated was the dose mortality, in terms of lethal concentration. This was calculated using 7-day surface-dose biological assays for each virus and a 1:1 mixture of OBs of the two against T. leucotreta neonates. The lethal concentrations of each treatment required to kill 50 % of larvae (LC50) and 90 % of larvae (LC90) for each treatment were then calculated and compared using a probit regression. The mixed infection performed significantly better than either virus by itself, while each virus by itself did not differ significantly from the other. The LC50 for CrleGV-SA, CrpeNPV and the mixed infection were 1.53 × 104 OBs/mL, 1.15 × 104 OBs/mL and 4.38 × 103 OBs/mL respectively. The LC90 of CrleGV-SA, CrpeNPV and the mixed infection were calculated to be 4.10 × 105 OBs/mL, 1.05 × 105 OBs/mL, and 4.09 × 104 OBs/mL respectively. The second aspect of the interaction between CrleGV-SA and CrpeNPV that was investigated was the speed of kill. A time-response biological assay protocol was created that allowed for effective observation of the larvae. This was then used to generate time-mortality data that were analysed by a logit regression function to calculate and compare the treatments at the time of 50 % larval mortality (LT50) and the time of 90 % mortality (LT90). Each virus by itself did not differ significantly from the other, while the mixed infection took significantly longer to kill 50 % and 90 % of the larvae, suggesting that there is competition for resources between viruses during the secondary, systemic phase of infection. The LT50 for CrleGV-SA, CrpeNPV and the mixed infection were 117.5 hours, 113.5 hours and 139.0 hours respectively. The LT90 for CrleGV-SA, CrpeNPV and the mixed infection were 153.2 hours, 159.3, and 193.4 hours respectively. Finally, the composition of OBs recovered from the cadavers produced by the time-response biological assays were investigated by mPCR. A method for extracting gDNA from OBs in neonate-sized T. leucotreta larvae is described. The presence of CrpeNPV along with CrleGV-SA was noted in 4 out of 9 larvae inoculated with only CrleGV-SA. The presence of CrleGV-SA as well as CrpeNPV was noted in all but one larva inoculated with only CrpeNPV, and both CrleGV-SA and CrpeNPV were noted in all but one larva inoculated with a 1:1 mixture of the two, with one larva only being positive for CrleGV-SA. This suggests either stock contamination or the presence of covert infections of CrleGV-SA and CrpeNPV in the T. leucotreta population used in this study. This is the second study to report an improved lethal concentration of a mixed infection of CrleGV-SA and CrpeNPV against T. leucotreta neonates, and the first study to report the slower speed of kill of a mixed infection of CrleGV-SA and CrpeNPV against T. leucotreta neonates. While the improved lethal concentration of the mixed infection is a promising step in the future improvement of baculovirus-based biopesticides, it is at the cost of a slower speed of kill. , Thesis (MSc) -- Faculty of Science, Department of Zoology and Entomology, 2021
- Full Text:
- Date Issued: 2021-04
- Authors: Taylor, David Graham
- Date: 2021-04
- Subjects: Baculoviruses , Cryptophlebia leucotreta , Cryptophlebia leucotreta -- Biological control , Biological pest control agents , Citrus -- Diseases and pests , Codling moth , Cryptophlebia peltastica nucleopolyhedrovirus (CrpeNPV)
- Language: English
- Type: thesis , text , Masters , MSc
- Identifier: http://hdl.handle.net/10962/176942 , vital:42774
- Description: Baculoviruses are an environmentally friendly and effective agent for managing lepidopteran pests. This includes the management of Thaumatotibia leucotreta (Meyrick) (Lepidoptera: Tortricidae), a serious pest of citrus in Southern Africa and a major threat to the South African citrus export industry. For more than 15 years, CrleGV-SA- based biopesticides have been used as part of an integrated pest management strategy for the control of T. leucotreta in citrus orchards in South Africa, under the names Cryptogran™ and Cryptex®. While these biopesticides have been effective during this period, there are some areas in which baculovirus use could potentially be improved. Baculoviruses are notoriously slow to kill in comparison to chemical-based pesticides, and lately, pest resistance to baculoviruses has become a major concern with the development of resistance by Cydia pomonella (Linnaeus) (Lepidoptera: Tortricidae) to its granulovirus occurring in the field in Europe. The consistent use of CrleGV-SA for more than 15 years in the field has raised concern that T. leucotreta could develop resistance to this virus, and has made it necessary to alter baculovirus-based management strategies to prevent this from occurring. A second baculovirus, Cryptophlebia peltastica nucleopolyhedrovirus (CrpeNPV), has recently been isolated and was shown to be effective against T. leucotreta. However, the interactions between CrleGV-SA and CrpeNPV are not yet understood and so it is important to test these interactions before both viruses are applied on the same orchards. Not only is it important to know whether these viruses could negatively impact each other, but it is also important to test whether they could interact synergistically. A synergistic interaction could not only provide a potential tool for the management of resistance, but it could also be exploited to improve baculovirus-based management of T. leucotreta. In this study, a stock of CrleGV-SA was purified by glycerol gradient centrifugation from T. leucotreta cadavers, while a stock of CrpeNPV purified from Cryptophlebia peltastica (Meyrick) (Lepidoptera: Tortricidae) cadavers was provided by River Bioscience (Pty) Ltd. These stocks were screened for purity by a multiplex polymerase chain reaction (mPCR) protocol designed to detect CrleGV-SA and CrpeNPV. The occlusion body (OB) density was then calculated using darkfield microscopy and a counting chamber. Both stocks were shown to be pure within the limits of the mPCR protocol, and the CrleGV-SA and CrpeNPV stocks were calculated to contain 3.08 × 1011 OBs/mL and 1.92 × 1011 OBs/mL respectively The first aspect of the interaction between CrleGV-SA and CrpeNPV that was investigated was the dose mortality, in terms of lethal concentration. This was calculated using 7-day surface-dose biological assays for each virus and a 1:1 mixture of OBs of the two against T. leucotreta neonates. The lethal concentrations of each treatment required to kill 50 % of larvae (LC50) and 90 % of larvae (LC90) for each treatment were then calculated and compared using a probit regression. The mixed infection performed significantly better than either virus by itself, while each virus by itself did not differ significantly from the other. The LC50 for CrleGV-SA, CrpeNPV and the mixed infection were 1.53 × 104 OBs/mL, 1.15 × 104 OBs/mL and 4.38 × 103 OBs/mL respectively. The LC90 of CrleGV-SA, CrpeNPV and the mixed infection were calculated to be 4.10 × 105 OBs/mL, 1.05 × 105 OBs/mL, and 4.09 × 104 OBs/mL respectively. The second aspect of the interaction between CrleGV-SA and CrpeNPV that was investigated was the speed of kill. A time-response biological assay protocol was created that allowed for effective observation of the larvae. This was then used to generate time-mortality data that were analysed by a logit regression function to calculate and compare the treatments at the time of 50 % larval mortality (LT50) and the time of 90 % mortality (LT90). Each virus by itself did not differ significantly from the other, while the mixed infection took significantly longer to kill 50 % and 90 % of the larvae, suggesting that there is competition for resources between viruses during the secondary, systemic phase of infection. The LT50 for CrleGV-SA, CrpeNPV and the mixed infection were 117.5 hours, 113.5 hours and 139.0 hours respectively. The LT90 for CrleGV-SA, CrpeNPV and the mixed infection were 153.2 hours, 159.3, and 193.4 hours respectively. Finally, the composition of OBs recovered from the cadavers produced by the time-response biological assays were investigated by mPCR. A method for extracting gDNA from OBs in neonate-sized T. leucotreta larvae is described. The presence of CrpeNPV along with CrleGV-SA was noted in 4 out of 9 larvae inoculated with only CrleGV-SA. The presence of CrleGV-SA as well as CrpeNPV was noted in all but one larva inoculated with only CrpeNPV, and both CrleGV-SA and CrpeNPV were noted in all but one larva inoculated with a 1:1 mixture of the two, with one larva only being positive for CrleGV-SA. This suggests either stock contamination or the presence of covert infections of CrleGV-SA and CrpeNPV in the T. leucotreta population used in this study. This is the second study to report an improved lethal concentration of a mixed infection of CrleGV-SA and CrpeNPV against T. leucotreta neonates, and the first study to report the slower speed of kill of a mixed infection of CrleGV-SA and CrpeNPV against T. leucotreta neonates. While the improved lethal concentration of the mixed infection is a promising step in the future improvement of baculovirus-based biopesticides, it is at the cost of a slower speed of kill. , Thesis (MSc) -- Faculty of Science, Department of Zoology and Entomology, 2021
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- Date Issued: 2021-04
The Influence of Clientelism on the Informal Sector in Zimbabwe : a Case Study of Glen View 8 Complex, Harare
- Authors: Tandire, Justin
- Date: 2021-04
- Subjects: Patron and client -- Zimbabwe -- Harare , Informal sector (Economics) -- Zimbabwe -- Harare , Informal sector (Economics) -- Political aspects -- Zimbabwe -- Harare , Patronage, Political -- Zimbabwe -- Harare , ZANU-PF (Organization : Zimbabwe) , Zimbabwe -- Social conditions , Glen View Complex 8 (Zimbabwe)
- Language: English
- Type: thesis , text , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/177986 , vital:42896 , 10.21504/10962/177986
- Description: This study focuses on the influence of clientelism in the informal sector of Zimbabwe in Glen View 8 (Complex). The study used the case of Glen view 8 (complex) in Harare Province. The study focused on political dynamics in the informal sector; livelihood strategies employed by informal sector operators; manifestation of “Big Men”, social networks in the informal sector; and different strategies employed by operators to overcome the problems of political manipulation, clientelism and patronage. It employs a qualitative research methodology to enable a nuanced comprehension of the clientelistic relationships that take place in the informal sector of Zimbabwe. Through in-depth interviews, focus group discussions, narratives and in-depth interviews with key informants, the study explored the clientelistic nature of the informal sector. The major findings of the study are that the informal sector in Zimbabwe is influenced by political patronage. It was established that patronage influences the informal sector in Zimbabwe in general and at Glen View Complex 8 in particular. Some of the operators revealed that patronage negatively affects their business as they are sometimes forced to attend political party meetings either at the complex or at ZANU-PF star rallies in town. The operators experience a plethora of problems such as lack of security, poor sanitation, stiff competition, poor infrastructure, lack of insurance and fire outbreaks. It has been revealed that most of the problems experienced at the complex are a result of the politicisation of the informal sector particularly by the ZANU-PF party. Operators at the complex have described the politicisation of the informal sector as a major drawback to their efforts of realising maximum benefits from their work. Therefore, the thrust of this thesis is premised on the de-politicisation of the informal sector as the starting point in the transformation of the activities of the operators. , Thesis (PhD) -- Faculty of Humanities, Sociology, 2021
- Full Text:
- Date Issued: 2021-04
- Authors: Tandire, Justin
- Date: 2021-04
- Subjects: Patron and client -- Zimbabwe -- Harare , Informal sector (Economics) -- Zimbabwe -- Harare , Informal sector (Economics) -- Political aspects -- Zimbabwe -- Harare , Patronage, Political -- Zimbabwe -- Harare , ZANU-PF (Organization : Zimbabwe) , Zimbabwe -- Social conditions , Glen View Complex 8 (Zimbabwe)
- Language: English
- Type: thesis , text , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/177986 , vital:42896 , 10.21504/10962/177986
- Description: This study focuses on the influence of clientelism in the informal sector of Zimbabwe in Glen View 8 (Complex). The study used the case of Glen view 8 (complex) in Harare Province. The study focused on political dynamics in the informal sector; livelihood strategies employed by informal sector operators; manifestation of “Big Men”, social networks in the informal sector; and different strategies employed by operators to overcome the problems of political manipulation, clientelism and patronage. It employs a qualitative research methodology to enable a nuanced comprehension of the clientelistic relationships that take place in the informal sector of Zimbabwe. Through in-depth interviews, focus group discussions, narratives and in-depth interviews with key informants, the study explored the clientelistic nature of the informal sector. The major findings of the study are that the informal sector in Zimbabwe is influenced by political patronage. It was established that patronage influences the informal sector in Zimbabwe in general and at Glen View Complex 8 in particular. Some of the operators revealed that patronage negatively affects their business as they are sometimes forced to attend political party meetings either at the complex or at ZANU-PF star rallies in town. The operators experience a plethora of problems such as lack of security, poor sanitation, stiff competition, poor infrastructure, lack of insurance and fire outbreaks. It has been revealed that most of the problems experienced at the complex are a result of the politicisation of the informal sector particularly by the ZANU-PF party. Operators at the complex have described the politicisation of the informal sector as a major drawback to their efforts of realising maximum benefits from their work. Therefore, the thrust of this thesis is premised on the de-politicisation of the informal sector as the starting point in the transformation of the activities of the operators. , Thesis (PhD) -- Faculty of Humanities, Sociology, 2021
- Full Text:
- Date Issued: 2021-04
A novel Arf GTPase assay for antimalarial drug discovery
- Authors: Swart, Tarryn
- Date: 2021-04
- Subjects: To be added
- Language: English
- Type: thesis , text , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/178558 , vital:42950
- Description: Access restricted until April 2022. , Thesis (PhD) -- Faculty of Science, Biochemistry and Microbiology, 2021
- Full Text:
- Date Issued: 2021-04
- Authors: Swart, Tarryn
- Date: 2021-04
- Subjects: To be added
- Language: English
- Type: thesis , text , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/178558 , vital:42950
- Description: Access restricted until April 2022. , Thesis (PhD) -- Faculty of Science, Biochemistry and Microbiology, 2021
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- Date Issued: 2021-04