Grazing sequence pattern and species selection by cattle in the Dohne sourveld
- Authors: Daines, Thomas
- Date: 1976
- Subjects: Grasses -- Research -- South Africa -- Cape of Good Hope , Grasses -- South Africa -- Cape of Good Hope -- Identification , Grazing -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4257 , http://hdl.handle.net/10962/d1010955
- Description: A detailed investigation into the harvesting of the standing grass crop within camps by cattle showed the following: 1. Cattle have a definite order of preference for the components of the Dohne Sourveld grass sward. The most palatable species in order of preference (based on Corrected Species Importance rating) are Themeda triandra, Tristachya hispida, Andropogon appendiculatus, Alloteropsis semialata and Heteropogon contortus. The least preferred species is Elionurus argenteus. 2. The key species, which is defined as the most abundant and productive palatable species, has been identified as Themeda triandra. 3. In harvesting the grass crop, cattle not only have a set preference for species, but also have a set grazing sequence pattern. This can be divided into three main phases. On entering the camp the animals first select the species of their choice, "creaming" these plants (grazed less than 50%) to obtain the most nutritious feed. In their daily search for food they spread their grazing over an increasingly wider area and over a wider range of species. When they can no longer obtain their daily requirements from this "creaming" operation of the more preferred species they return to the most preferred species , which are then heavily grazed (more than 50%) producing the common pattern of area grazing within a camp. These areas increase in size as the cattle graze down the species of their choice, moving to less preferred species as soon as they can no longer obtain their daily intake requirements from the more preferred species. Finally when they have no alternative they graze the least preferred species. 4. Increasing the stocking density does not alter the grazing sequence pattern or change the order of preference for the component species in the sward. It only increases the rate of utilization of the more preferred species and the various phases in the grazing sequence pattern are reached more rapidly. 5. At higher stocking densities the palatable species are more evenly utilized than at lower stocking densities. 6. Cattle graze a greater variety of species when the sward is young and actively growing. As the maturity of the sward increases the cattle concentrate on the more preferred species and are more selective in their grazing. However, their order of preference remains the same. Species that are highly preferred early in the season retain their ranking when the sward is mature. The only exception to this rule is Alloteropsis semialata. Early in the growing season this species is high on the preference list, but as it matures less is taken until when fully mature, it is rejected by cattle. 7. Elionurus argenteus is the least preferred of all the species in the Dohne Sourveld. Cattle will graze this plant as a last resort when grazing a camp early in the season, but reject the plant when it is fully mature. 8. To retain vigour and production of the Dohne Sourveld results of this investigation support the view that grazing management should be based on the principle of controlled selective grazing. Having shown that the more preferred species are over-utilized when attempting to utilize the least preferred species any grazing management that calls for total utilization of all standing vegetation should be rejected. 9. The results of this investigation supports a multicamp system for the Dohne Sourveld where high stocking densities are employed. This will result in the rapid and even utilization of the more preferred species. Management should be based on short period of stay and long period of absence. Cattle should be moved as soon as the key species have been well utilized, but not overgrazed. Cattle should only be returned to the camp when key species have made adequate regrowth following grazing. 10. A method, that is simple to use, is proposed for determining utilization of the veld and key species at different times of the year using the relationship between percentage of ungrazed plants and utilization of the sward and of Themeda triandra, the key grazing species in the sward. 11. Results show that when rested camps are grazed after May, the number of Themeda triandra inflorescences are drastically reduced. Veld that is specifically rested for the production of Themeda triandra seed should be rested from March of the year preceding expected seeding.
- Full Text:
- Date Issued: 1976
- Authors: Daines, Thomas
- Date: 1976
- Subjects: Grasses -- Research -- South Africa -- Cape of Good Hope , Grasses -- South Africa -- Cape of Good Hope -- Identification , Grazing -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4257 , http://hdl.handle.net/10962/d1010955
- Description: A detailed investigation into the harvesting of the standing grass crop within camps by cattle showed the following: 1. Cattle have a definite order of preference for the components of the Dohne Sourveld grass sward. The most palatable species in order of preference (based on Corrected Species Importance rating) are Themeda triandra, Tristachya hispida, Andropogon appendiculatus, Alloteropsis semialata and Heteropogon contortus. The least preferred species is Elionurus argenteus. 2. The key species, which is defined as the most abundant and productive palatable species, has been identified as Themeda triandra. 3. In harvesting the grass crop, cattle not only have a set preference for species, but also have a set grazing sequence pattern. This can be divided into three main phases. On entering the camp the animals first select the species of their choice, "creaming" these plants (grazed less than 50%) to obtain the most nutritious feed. In their daily search for food they spread their grazing over an increasingly wider area and over a wider range of species. When they can no longer obtain their daily requirements from this "creaming" operation of the more preferred species they return to the most preferred species , which are then heavily grazed (more than 50%) producing the common pattern of area grazing within a camp. These areas increase in size as the cattle graze down the species of their choice, moving to less preferred species as soon as they can no longer obtain their daily intake requirements from the more preferred species. Finally when they have no alternative they graze the least preferred species. 4. Increasing the stocking density does not alter the grazing sequence pattern or change the order of preference for the component species in the sward. It only increases the rate of utilization of the more preferred species and the various phases in the grazing sequence pattern are reached more rapidly. 5. At higher stocking densities the palatable species are more evenly utilized than at lower stocking densities. 6. Cattle graze a greater variety of species when the sward is young and actively growing. As the maturity of the sward increases the cattle concentrate on the more preferred species and are more selective in their grazing. However, their order of preference remains the same. Species that are highly preferred early in the season retain their ranking when the sward is mature. The only exception to this rule is Alloteropsis semialata. Early in the growing season this species is high on the preference list, but as it matures less is taken until when fully mature, it is rejected by cattle. 7. Elionurus argenteus is the least preferred of all the species in the Dohne Sourveld. Cattle will graze this plant as a last resort when grazing a camp early in the season, but reject the plant when it is fully mature. 8. To retain vigour and production of the Dohne Sourveld results of this investigation support the view that grazing management should be based on the principle of controlled selective grazing. Having shown that the more preferred species are over-utilized when attempting to utilize the least preferred species any grazing management that calls for total utilization of all standing vegetation should be rejected. 9. The results of this investigation supports a multicamp system for the Dohne Sourveld where high stocking densities are employed. This will result in the rapid and even utilization of the more preferred species. Management should be based on short period of stay and long period of absence. Cattle should be moved as soon as the key species have been well utilized, but not overgrazed. Cattle should only be returned to the camp when key species have made adequate regrowth following grazing. 10. A method, that is simple to use, is proposed for determining utilization of the veld and key species at different times of the year using the relationship between percentage of ungrazed plants and utilization of the sward and of Themeda triandra, the key grazing species in the sward. 11. Results show that when rested camps are grazed after May, the number of Themeda triandra inflorescences are drastically reduced. Veld that is specifically rested for the production of Themeda triandra seed should be rested from March of the year preceding expected seeding.
- Full Text:
- Date Issued: 1976
Semantiese velde en die onderrig en aanleer van Xhosa-woordeskat
- Authors: Venter, Johannes Andreas
- Date: 1980
- Subjects: Xhosa language -- Semantics , Xhosa language -- Vocabulary , Xhosa language -- Study and teaching
- Language: Afrikaans
- Type: Thesis , Masters , MA
- Identifier: vital:3606 , http://hdl.handle.net/10962/d1003814 , Xhosa language -- Semantics , Xhosa language -- Vocabulary , Xhosa language -- Study and teaching
- Description: Uit Inleiding: Hoe belangrik is die aanleer van woordeskat by die verwerwing van 'n vreemde taal? Indien dit van besondere belang is, kan met reg gevra word: watter beginsels moet in ag geneem word by die opstel van metodes en tegnieke om die aanleer van die woordeskat met optimum effektiwiteit te laat plaasvind? Wat is die teoretiese basis vir sulke metodes en tegnieke? Hierdie is enkele vrae wat in hierdie ondersoek aan die orde sal kom. Die begrip "semantiese velde" of "betekenisvelde" is 'n idee wat in die jongste tyd heelwat aandag geniet by linguiste. Die konsep "betekenisveld" veronderstel twee kenmerke van die leksikon: 1. Dat die betekenisaspek van elke individuele leksikale item, kragtens kontras bestaan en dat hierdie kontras tussen betekeniskomponente van leksikale items in die leksikon teregkom, veral binne 'n betekenisveldsiening. 2. Dat die leksikon kragtens die relasies tussen die leksikale items 'n georganiseerde en gestruktureerde versameling is. In ons ondersoek sal dit dus hoofsaaklik gaan oor: 1. Bestaande metodes en tegnieke om woordeskat te onderrig. 2. Bestaande toerieë oor die gestruktureerdheid van woordeskat. 3. Die moontlikhede wat hierdie teorieë inhou, om die onderrig van woordeskat meer effektief te laat plaasvind.
- Full Text:
- Date Issued: 1980
- Authors: Venter, Johannes Andreas
- Date: 1980
- Subjects: Xhosa language -- Semantics , Xhosa language -- Vocabulary , Xhosa language -- Study and teaching
- Language: Afrikaans
- Type: Thesis , Masters , MA
- Identifier: vital:3606 , http://hdl.handle.net/10962/d1003814 , Xhosa language -- Semantics , Xhosa language -- Vocabulary , Xhosa language -- Study and teaching
- Description: Uit Inleiding: Hoe belangrik is die aanleer van woordeskat by die verwerwing van 'n vreemde taal? Indien dit van besondere belang is, kan met reg gevra word: watter beginsels moet in ag geneem word by die opstel van metodes en tegnieke om die aanleer van die woordeskat met optimum effektiwiteit te laat plaasvind? Wat is die teoretiese basis vir sulke metodes en tegnieke? Hierdie is enkele vrae wat in hierdie ondersoek aan die orde sal kom. Die begrip "semantiese velde" of "betekenisvelde" is 'n idee wat in die jongste tyd heelwat aandag geniet by linguiste. Die konsep "betekenisveld" veronderstel twee kenmerke van die leksikon: 1. Dat die betekenisaspek van elke individuele leksikale item, kragtens kontras bestaan en dat hierdie kontras tussen betekeniskomponente van leksikale items in die leksikon teregkom, veral binne 'n betekenisveldsiening. 2. Dat die leksikon kragtens die relasies tussen die leksikale items 'n georganiseerde en gestruktureerde versameling is. In ons ondersoek sal dit dus hoofsaaklik gaan oor: 1. Bestaande metodes en tegnieke om woordeskat te onderrig. 2. Bestaande toerieë oor die gestruktureerdheid van woordeskat. 3. Die moontlikhede wat hierdie teorieë inhou, om die onderrig van woordeskat meer effektief te laat plaasvind.
- Full Text:
- Date Issued: 1980
A hydrogeological investigation of Grahamstown, assessing both the dynamics and quality of the local groundwater system
- Authors: Smetherham, Kyle Norman
- Date: 2019
- Subjects: Hydrogeology -- South Africa -- Makhanda , Water quality -- South Africa -- Makhanda , Groundwater -- Quality -- South Africa -- Makhanda
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/94444 , vital:31045
- Description: In many parts of South Africa, complete allocation of surface water reservoirs together with current drought conditions has led to serious water shortages and subsequent awareness regarding the importance to save water. Grahamstown is no different, with water problems relating to low supply and high demand being compounded by insufficient treatment capacity and aging infrastructure. Groundwater is an alternative water resource that could potentially act as a supplementary and/or emergency supply to the town, reducing the reliability on surface reservoirs. Groundwater however, is a hidden resource and requires an understanding of various aquifer properties and continuous monitoring and modelling so not to permanently disrupt the natural system but rather achieve sustainable management. Grahamstown is situated towards the northern extent of the Cape Fold Belt (CFB) system, within a synclinal fold structure. The local geology forms two local aquifer systems beneath Grahamstown that directly influence both the dynamics and quality of the groundwater. These underground reservoirs are the Witpoort and Dwyka aquifers and can be described as a semi-confined, fractured, quartzitic sandstone aquifer and an unconfined, fractured, tillite aquifer, respectively. Separating these aquifer systems is a shale aquitard, although due to the fractured nature of the rocks in the region there is most likely some groundwater interaction between them. Evaluation of geological formations together with the monitoring of 31 local boreholes presented a valuable conceptualisation of the local system and allowed for the application of methods to estimate recharge. Recharge estimation is one of the most crucial factors when managing aquifer systems as it can be used to determine what proportion of rainfall contributes to the subsurface reservoir and therefore, the sustainable amount that can be extracted. Various methods have been developed to estimate recharge, however due to the uncertainty surrounding groundwater systems, especially fractured aquifers, it was important to apply multiple methods to validate results. The water-table fluctuation (WTF) and cumulative rainfall departure (CRD) are two methods that were used in the present study to determine recharge. These methods rely on water-table changes in boreholes and specifically how they respond to rainfall events. Along with the WTF and CRD methods, a modelling approach was also used to estimate recharge which focused on the dynamics of a natural groundwater outlet, termed the Fairview Spring. This natural spring system is located just outside the main town of Grahamstown, within the Witpoort aquifer system, and is an important water resource to many residents due to poor supply and quality of municipal water. Monitoring the discharge of this spring allowed for the development of a model which attempts to recreate the discharge conditions observed. Along with groundwater recharge, other processes added to the model include evapotranspiration, storage, interflow spring outflow and groundwater outflow. Several different model simulation scenarios provided valuable insight into the greater groundwater dynamics. In terms of groundwater quality, nine borehole samples and one spring sample were analysed for major ions (Ca, Na, K, Cl, Mg, SO4, HCO3), metals (Cu, Fe, Mn) as well as pH and electrical conductivity. Overall electrical conductivity levels and major ion concentrations were lower in the Witpoort aquifer indicating a better groundwater quality compared to that of the Dwyka aquifer. Of the three metals included in the analysis, Mn proved to be the most significant and the highest concentrations were produced for samples that intersected the shale aquitard unit, suggesting that Mn-containing groundwater is drawn from this geological layer. Development of a supplementary and/or emergency groundwater supply requires careful consideration of the geology, quantity, quality, and recharge in the study site. All these aspects were assessed as well as deliberation into the potential infrastructural costs involved. Through conceptualisation of the system; evidence gathered during basic monitoring; and a simple spring model, the current study aimed to explore certain management strategies and recommend potential options going forward. The hidden nature of the resource together with the heterogeneity of fracture networks creates an inevitable uncertainty surrounding the system. Proper development and management of the aquifer can only be achieved if the system is continually monitored, modelled and utilised sustainably.
- Full Text:
- Date Issued: 2019
- Authors: Smetherham, Kyle Norman
- Date: 2019
- Subjects: Hydrogeology -- South Africa -- Makhanda , Water quality -- South Africa -- Makhanda , Groundwater -- Quality -- South Africa -- Makhanda
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/94444 , vital:31045
- Description: In many parts of South Africa, complete allocation of surface water reservoirs together with current drought conditions has led to serious water shortages and subsequent awareness regarding the importance to save water. Grahamstown is no different, with water problems relating to low supply and high demand being compounded by insufficient treatment capacity and aging infrastructure. Groundwater is an alternative water resource that could potentially act as a supplementary and/or emergency supply to the town, reducing the reliability on surface reservoirs. Groundwater however, is a hidden resource and requires an understanding of various aquifer properties and continuous monitoring and modelling so not to permanently disrupt the natural system but rather achieve sustainable management. Grahamstown is situated towards the northern extent of the Cape Fold Belt (CFB) system, within a synclinal fold structure. The local geology forms two local aquifer systems beneath Grahamstown that directly influence both the dynamics and quality of the groundwater. These underground reservoirs are the Witpoort and Dwyka aquifers and can be described as a semi-confined, fractured, quartzitic sandstone aquifer and an unconfined, fractured, tillite aquifer, respectively. Separating these aquifer systems is a shale aquitard, although due to the fractured nature of the rocks in the region there is most likely some groundwater interaction between them. Evaluation of geological formations together with the monitoring of 31 local boreholes presented a valuable conceptualisation of the local system and allowed for the application of methods to estimate recharge. Recharge estimation is one of the most crucial factors when managing aquifer systems as it can be used to determine what proportion of rainfall contributes to the subsurface reservoir and therefore, the sustainable amount that can be extracted. Various methods have been developed to estimate recharge, however due to the uncertainty surrounding groundwater systems, especially fractured aquifers, it was important to apply multiple methods to validate results. The water-table fluctuation (WTF) and cumulative rainfall departure (CRD) are two methods that were used in the present study to determine recharge. These methods rely on water-table changes in boreholes and specifically how they respond to rainfall events. Along with the WTF and CRD methods, a modelling approach was also used to estimate recharge which focused on the dynamics of a natural groundwater outlet, termed the Fairview Spring. This natural spring system is located just outside the main town of Grahamstown, within the Witpoort aquifer system, and is an important water resource to many residents due to poor supply and quality of municipal water. Monitoring the discharge of this spring allowed for the development of a model which attempts to recreate the discharge conditions observed. Along with groundwater recharge, other processes added to the model include evapotranspiration, storage, interflow spring outflow and groundwater outflow. Several different model simulation scenarios provided valuable insight into the greater groundwater dynamics. In terms of groundwater quality, nine borehole samples and one spring sample were analysed for major ions (Ca, Na, K, Cl, Mg, SO4, HCO3), metals (Cu, Fe, Mn) as well as pH and electrical conductivity. Overall electrical conductivity levels and major ion concentrations were lower in the Witpoort aquifer indicating a better groundwater quality compared to that of the Dwyka aquifer. Of the three metals included in the analysis, Mn proved to be the most significant and the highest concentrations were produced for samples that intersected the shale aquitard unit, suggesting that Mn-containing groundwater is drawn from this geological layer. Development of a supplementary and/or emergency groundwater supply requires careful consideration of the geology, quantity, quality, and recharge in the study site. All these aspects were assessed as well as deliberation into the potential infrastructural costs involved. Through conceptualisation of the system; evidence gathered during basic monitoring; and a simple spring model, the current study aimed to explore certain management strategies and recommend potential options going forward. The hidden nature of the resource together with the heterogeneity of fracture networks creates an inevitable uncertainty surrounding the system. Proper development and management of the aquifer can only be achieved if the system is continually monitored, modelled and utilised sustainably.
- Full Text:
- Date Issued: 2019
Popular politics in the rural Western Cape, South Africa: a case study of Ruiterbos
- Authors: Ghedi Alasow, Jonis
- Date: 2019
- Subjects: Political participation -- South Africa -- Cape Town , South Africa -- Politics and government -- 1994- , Land tenure -- Political aspects -- South Africa , Land use, Rural -- Political aspects -- South Africa
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/96165 , vital:31246
- Description: This thesis argues that the philosophical foundations upon which human beings have been engaged have, across various schools of thought, made the mistake of presuming that some people are more modern than others. This suggestion is refuted throughout this thesis. To do this, intellectual traditions that take the fundamental rationality of all human beings as an indispensable starting point are engaged to argue for the need to acknowledge that everyone in the ‘now’ is indeed, of the ‘now’. This thesis connects these debates about modernity, rationality and humanity to the contemporary discussions around rural politics with particular reference to Ruiterbos in the Western Cape province of South Africa. By means of detailed empirical and ethnographic research, this thesis illustrates the issues around which people in Ruiterbos are politicised. Via this case study, the a priori assumption that rural politics will necessarily manifest itself only with respect to questions of land and agrarian reform or labour relations is complicated. The two issues around which people in Ruiterbos, during the time of this research, seem to be politicised – housing and education – are surfaced throughout this thesis. The thesis argues that the findings in this case study call for an expansion of the issues that are traditionally considered when the question of rural politics is raised. The often historicist approach that limits the possibilities for politics in rural areas should be suspended for an approach that takes popular politics and political agents in rural areas seriously. The thesis finally argues that the conclusions that are reached with respect to questions of modernity and rural politics ought to be adopted to allow for more detailed and thorough explanations of popular politics in places like Ruiterbos.
- Full Text:
- Date Issued: 2019
- Authors: Ghedi Alasow, Jonis
- Date: 2019
- Subjects: Political participation -- South Africa -- Cape Town , South Africa -- Politics and government -- 1994- , Land tenure -- Political aspects -- South Africa , Land use, Rural -- Political aspects -- South Africa
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/96165 , vital:31246
- Description: This thesis argues that the philosophical foundations upon which human beings have been engaged have, across various schools of thought, made the mistake of presuming that some people are more modern than others. This suggestion is refuted throughout this thesis. To do this, intellectual traditions that take the fundamental rationality of all human beings as an indispensable starting point are engaged to argue for the need to acknowledge that everyone in the ‘now’ is indeed, of the ‘now’. This thesis connects these debates about modernity, rationality and humanity to the contemporary discussions around rural politics with particular reference to Ruiterbos in the Western Cape province of South Africa. By means of detailed empirical and ethnographic research, this thesis illustrates the issues around which people in Ruiterbos are politicised. Via this case study, the a priori assumption that rural politics will necessarily manifest itself only with respect to questions of land and agrarian reform or labour relations is complicated. The two issues around which people in Ruiterbos, during the time of this research, seem to be politicised – housing and education – are surfaced throughout this thesis. The thesis argues that the findings in this case study call for an expansion of the issues that are traditionally considered when the question of rural politics is raised. The often historicist approach that limits the possibilities for politics in rural areas should be suspended for an approach that takes popular politics and political agents in rural areas seriously. The thesis finally argues that the conclusions that are reached with respect to questions of modernity and rural politics ought to be adopted to allow for more detailed and thorough explanations of popular politics in places like Ruiterbos.
- Full Text:
- Date Issued: 2019
Recovery and molecular identification of Aichi virus 1, enteric human bocaviruses and enteric human adenoviruses in untreated sewage and mussel samples collected in the Eastern Cape Province of South Africa
- Authors: Onosi, Oikwathaile
- Date: 2019
- Subjects: Sewage -- Analysis -- South Africa -- Eastern Cape , Sewage -- Microbiology -- South Africa -- Eastern Cape , Viral pollution of water -- South Africa -- Eastern Cape , Sewage disposal in rivers, lakes, etc. -- South Africa -- Eastern Cape , Enteroviruses -- South Africa -- Eastern Cape , Picornaviruses -- South Africa -- Eastern Cape , Aichi virus 1 , Parvoviruses -- South Africa -- Eastern Cape , Adenoviruses -- South Africa -- Eastern Cape
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/69456 , vital:29539
- Description: Gastroenteritis, commonly known as diarrhoeal disease, is one of the top killers responsible for substantial human morbidity and mortality especially in third world countries where most people do not have access to potable water and where hygiene levels are low. Many bacterial, viral and protozoal agents are known causes of gastroenteritis and viral gastroenteritis is responsible for over 70% of cases. Rotaviruses are the main causes of viral gastroenteritis and are responsible for most of the cases worldwide. Other viral agents associated with this disease include human noroviruses, Aichi virus 1, enteric human bocavirus, enteric human adenovirus and many other emerging viral agents such as klassivirus, Saffold virus, cosavirus and others. In 2009 the South African government introduced a rotavirus vaccine, RotaRixTM into the expanded programme on immunisation (EPI). More than a 50% decrease in diarrhoea related morbidity and mortality due to rotavirus infections was noted during surveillance studies on the efficacy of the vaccine. However, over 40% of cases of gastroenteritis are of unknown aetiology. The present study aimed to perform a preliminary study to investigate the presence of Aichi virus 1 and enteric human bocaviruses in the Eastern Cape Province by the use of molecular techniques. Furthermore, the study aimed to add to the limited molecular data about enteric adenoviruses in South Africa. Samples used in this study were swab samples collected from Belmont Valley Wastewater Treatment Plant in Grahamstown, South Africa, as well as mussel samples collected from the Swartkops River in Port Elizabeth, South Africa. Both raw sewage and shellfish give a broad idea of what microbes are circulating in the communities. In the present study, twenty swabs and twenty mussel samples were prepared by centrifugation, sonication and filtration. Samples were then subjected to transmission electron microscopy (TEM) analysis, for which the electron micrographs revealed presence of viral particles with diameters ranging from around 20 nm to just over 100 nm. Viral nucleic acids were extracted from 140 μL of the twenty swabs and twenty mussels samples using the QIAamp® Viral RNA Mini Kit, following manufacturer‟s instructions. For detection of Aichi virus 1 from the swab and mussel samples three reverse transcriptase- polymerase chain reaction (RT-PCR) assays using the Verso 1-Step RT-PCR Hot-Start Kit were developed. The first RT-PCR assay targeted amplification of the highly conserved 5′ UTR using published primers. However, despite many amplification attempts no positive results were obtained from both swab and mussel samples. It was only after the addition of DMSO (to a final concentration of 10%) that one swab sample was positive for this assay. In addition, a 2-step RT-PCR was developed using the Maxima H Minus First Strand cDNA Synthesis Kit. By using this 2-step RT-PCR assay, an additional swab sample was positive for the Aichi virus 1 5′ UTR. Using Basic Logarithm Alignment Search Tool (BLAST) analysis these two samples were 98% identical to an Aichi virus isolate from South Korea. The second one-step RT-PCR assay targeted amplification of the 266 bp partial 3CD coding region of Aichi virus 1 using published primers. By using this assay, positive results were obtained from both the swab and mussel samples, which when analysed by BLAST were all 99% identical to various Aichi virus 1 isolates in GenBank. A phylogenetic tree constructed based on this region showed that isolates from the present study clustered with Genotype B isolates in GenBank. The third assay was a semi-nested RT-PCR assay that targeted amplification of the hypervariable VP1 coding region of Aichi virus 1 using a combination of published primers and those designed in the present study. Amplicons which were 472 bp in size were produced from two swab samples. When analysed by BLAST, these two swab samples had percentage identities of 98% to an Aichi virus isolate from South Korea. A phylogenetic tree constructed based on this region showed that isolates from the present study clustered with Genotype B isolates in GenBank. This was consistent with phylogenetic results discussed above which were based on the partial 3CD region. For detection of enteric human bocaviruses from the swab and mussel samples a nested polymerase chain reaction (PCR) assay, using the Ampliqon Taq PCR kit (Ampliqon Bio Reagents and Molecular Diagnostics, Denmark) was developed based on PCR amplification of the 382 bp partial VP1/VP2 coding region using published primers. A total of six swab samples and six mussel samples were analysed for which five swabs and six mussel samples gave positive results. When analysed by BLAST, the swab samples had percentage identities of between 98% and 99% to an enteric human bocavirus 3 strain from China while the mussel samples were all 99% identical to an enteric human bocavirus 2 isolate from Australia. A phylogenetic tree constructed based on this VP1/VP2 region showed that isolates from the present study clustered with human bocavirus 2 and human bocavirus 3 isolates in GenBank for those isolated from swab samples and mussel samples respectively. Lastly, for detection of enteric human adenoviruses from the swab and mussel samples a nested PCR assay, using the Ampliqon Taq PCR kit (Ampliqon Bio Reagents and Molecular Diagnostics, Denmark) was developed. This reaction was based on PCR amplification of the 168 bp partial hexon coding region using published primers for which ten swab samples gave positive results. When analysed by BLAST, the swab samples had percentage identities of between 96% and 99% to enteric human adenoviruses in GenBank. A phylogenetic tree constructed based on the hexon coding region showed that isolates from the present study clustered with subtypes C, D and F which are associated with gastroenteritis worldwide. Despite several amplification attempts no positive results were obtained from mussel samples. The results from the present study show that Aichi virus 1, enteric bocaviruses and enteric adenoviruses are present in the Eastern Cape Province of South Africa. These viruses could possibly be responsible for enteric infections in South Africa. Although only a few samples were analysed, this study is the first to confirm the presence of Aichi virus 1 and enteric bocaviruses in South Africa and provides a platform for further investigation into prevalence and epidemiology of these viruses in the country.
- Full Text:
- Date Issued: 2019
- Authors: Onosi, Oikwathaile
- Date: 2019
- Subjects: Sewage -- Analysis -- South Africa -- Eastern Cape , Sewage -- Microbiology -- South Africa -- Eastern Cape , Viral pollution of water -- South Africa -- Eastern Cape , Sewage disposal in rivers, lakes, etc. -- South Africa -- Eastern Cape , Enteroviruses -- South Africa -- Eastern Cape , Picornaviruses -- South Africa -- Eastern Cape , Aichi virus 1 , Parvoviruses -- South Africa -- Eastern Cape , Adenoviruses -- South Africa -- Eastern Cape
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/69456 , vital:29539
- Description: Gastroenteritis, commonly known as diarrhoeal disease, is one of the top killers responsible for substantial human morbidity and mortality especially in third world countries where most people do not have access to potable water and where hygiene levels are low. Many bacterial, viral and protozoal agents are known causes of gastroenteritis and viral gastroenteritis is responsible for over 70% of cases. Rotaviruses are the main causes of viral gastroenteritis and are responsible for most of the cases worldwide. Other viral agents associated with this disease include human noroviruses, Aichi virus 1, enteric human bocavirus, enteric human adenovirus and many other emerging viral agents such as klassivirus, Saffold virus, cosavirus and others. In 2009 the South African government introduced a rotavirus vaccine, RotaRixTM into the expanded programme on immunisation (EPI). More than a 50% decrease in diarrhoea related morbidity and mortality due to rotavirus infections was noted during surveillance studies on the efficacy of the vaccine. However, over 40% of cases of gastroenteritis are of unknown aetiology. The present study aimed to perform a preliminary study to investigate the presence of Aichi virus 1 and enteric human bocaviruses in the Eastern Cape Province by the use of molecular techniques. Furthermore, the study aimed to add to the limited molecular data about enteric adenoviruses in South Africa. Samples used in this study were swab samples collected from Belmont Valley Wastewater Treatment Plant in Grahamstown, South Africa, as well as mussel samples collected from the Swartkops River in Port Elizabeth, South Africa. Both raw sewage and shellfish give a broad idea of what microbes are circulating in the communities. In the present study, twenty swabs and twenty mussel samples were prepared by centrifugation, sonication and filtration. Samples were then subjected to transmission electron microscopy (TEM) analysis, for which the electron micrographs revealed presence of viral particles with diameters ranging from around 20 nm to just over 100 nm. Viral nucleic acids were extracted from 140 μL of the twenty swabs and twenty mussels samples using the QIAamp® Viral RNA Mini Kit, following manufacturer‟s instructions. For detection of Aichi virus 1 from the swab and mussel samples three reverse transcriptase- polymerase chain reaction (RT-PCR) assays using the Verso 1-Step RT-PCR Hot-Start Kit were developed. The first RT-PCR assay targeted amplification of the highly conserved 5′ UTR using published primers. However, despite many amplification attempts no positive results were obtained from both swab and mussel samples. It was only after the addition of DMSO (to a final concentration of 10%) that one swab sample was positive for this assay. In addition, a 2-step RT-PCR was developed using the Maxima H Minus First Strand cDNA Synthesis Kit. By using this 2-step RT-PCR assay, an additional swab sample was positive for the Aichi virus 1 5′ UTR. Using Basic Logarithm Alignment Search Tool (BLAST) analysis these two samples were 98% identical to an Aichi virus isolate from South Korea. The second one-step RT-PCR assay targeted amplification of the 266 bp partial 3CD coding region of Aichi virus 1 using published primers. By using this assay, positive results were obtained from both the swab and mussel samples, which when analysed by BLAST were all 99% identical to various Aichi virus 1 isolates in GenBank. A phylogenetic tree constructed based on this region showed that isolates from the present study clustered with Genotype B isolates in GenBank. The third assay was a semi-nested RT-PCR assay that targeted amplification of the hypervariable VP1 coding region of Aichi virus 1 using a combination of published primers and those designed in the present study. Amplicons which were 472 bp in size were produced from two swab samples. When analysed by BLAST, these two swab samples had percentage identities of 98% to an Aichi virus isolate from South Korea. A phylogenetic tree constructed based on this region showed that isolates from the present study clustered with Genotype B isolates in GenBank. This was consistent with phylogenetic results discussed above which were based on the partial 3CD region. For detection of enteric human bocaviruses from the swab and mussel samples a nested polymerase chain reaction (PCR) assay, using the Ampliqon Taq PCR kit (Ampliqon Bio Reagents and Molecular Diagnostics, Denmark) was developed based on PCR amplification of the 382 bp partial VP1/VP2 coding region using published primers. A total of six swab samples and six mussel samples were analysed for which five swabs and six mussel samples gave positive results. When analysed by BLAST, the swab samples had percentage identities of between 98% and 99% to an enteric human bocavirus 3 strain from China while the mussel samples were all 99% identical to an enteric human bocavirus 2 isolate from Australia. A phylogenetic tree constructed based on this VP1/VP2 region showed that isolates from the present study clustered with human bocavirus 2 and human bocavirus 3 isolates in GenBank for those isolated from swab samples and mussel samples respectively. Lastly, for detection of enteric human adenoviruses from the swab and mussel samples a nested PCR assay, using the Ampliqon Taq PCR kit (Ampliqon Bio Reagents and Molecular Diagnostics, Denmark) was developed. This reaction was based on PCR amplification of the 168 bp partial hexon coding region using published primers for which ten swab samples gave positive results. When analysed by BLAST, the swab samples had percentage identities of between 96% and 99% to enteric human adenoviruses in GenBank. A phylogenetic tree constructed based on the hexon coding region showed that isolates from the present study clustered with subtypes C, D and F which are associated with gastroenteritis worldwide. Despite several amplification attempts no positive results were obtained from mussel samples. The results from the present study show that Aichi virus 1, enteric bocaviruses and enteric adenoviruses are present in the Eastern Cape Province of South Africa. These viruses could possibly be responsible for enteric infections in South Africa. Although only a few samples were analysed, this study is the first to confirm the presence of Aichi virus 1 and enteric bocaviruses in South Africa and provides a platform for further investigation into prevalence and epidemiology of these viruses in the country.
- Full Text:
- Date Issued: 2019
Cranial ontogeny of the sole, dagetichthys marginatus (soleidae), with considerations on the feeding ability of larvae and early juveniles
- Ende, Stephan Siegfried Werner
- Authors: Ende, Stephan Siegfried Werner
- Date: 2008
- Subjects: Soleidae , Fishes -- Larvae -- Food , Flatfishes -- Nutrition , Artemia
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5250 , http://hdl.handle.net/10962/d1005093 , Soleidae , Fishes -- Larvae -- Food , Flatfishes -- Nutrition , Artemia
- Description: The overall aim of this study was to gain a better understanding of the feeding mechanisms of the larvae and early juveniles of the sole, Dagetichthys marginatus (Soleidae), with which to assess the suitability of current feeding protocols and to facilitate the development of an appropriate pelleted feed. This was achieved by examining the ontogeny of the cranium of laboratory reared sole, with particular emphasis on those elements associated with feeding and by comparing the cranium of juvenile fish with that of adult fish. At 4 dah (days after hatch) Dagetichthys marginatus larvae develop the first rudimentary branchial arches that facilitates the capture and ingestion of food items. Subsequent development of cranial structures, such as the oral jaws, suspensorium, neurocranium, hyoid and branchial arches and the opercular apparatus enables the larvae, at 16 dah, to switch from ram feeding to suction feeding on live prey. The use of live Artemia nauplii from 4 to 16 dah is therefore appropriate. The first morphological asymmetries developed at 16 dah in the dentaries and at 22 dah the maxillae and the premaxillae began to show asymmetries. Teeth were present only on the blind side of the oral jaw elements and during this period (16 to 22 dah) the existing elements began to ossify. From 16 to 35 dah the standard feeding protocol consists of a combination of pelagic (Artemia metanauplii) and benthic prey (dead, frozen Artemia nauplii) and from 25 dah onwards a sinking pellet is provided. The time (dah) at which frozen Artemia and sinking pellets were provided, appropriately corresponded to the initiation of benthic feeding behaviour. However at this stage the use of pelagic Artemia metanauplii is inappropriate and unnecessary. At 31 dah the cranial morphology resembled that of adult fish. Adult D. marginatus display extreme asymmetries among the elements of the oral jaws, the suspensorium and certain elements of the neurocranium. Elements on the blind side are larger and more robust than those on the ocular side and are adapted for feeding, while those on the ocular side appear to have a respiratory function. From 31 dah the cranial elements are identical to those of adult fish, suggesting that no further feeding behavioural changes occurred and that a sinking pellet, of which the nutrient composition meets the requirements of the fish, would be appropriate for ongrowing.
- Full Text:
- Date Issued: 2008
- Authors: Ende, Stephan Siegfried Werner
- Date: 2008
- Subjects: Soleidae , Fishes -- Larvae -- Food , Flatfishes -- Nutrition , Artemia
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5250 , http://hdl.handle.net/10962/d1005093 , Soleidae , Fishes -- Larvae -- Food , Flatfishes -- Nutrition , Artemia
- Description: The overall aim of this study was to gain a better understanding of the feeding mechanisms of the larvae and early juveniles of the sole, Dagetichthys marginatus (Soleidae), with which to assess the suitability of current feeding protocols and to facilitate the development of an appropriate pelleted feed. This was achieved by examining the ontogeny of the cranium of laboratory reared sole, with particular emphasis on those elements associated with feeding and by comparing the cranium of juvenile fish with that of adult fish. At 4 dah (days after hatch) Dagetichthys marginatus larvae develop the first rudimentary branchial arches that facilitates the capture and ingestion of food items. Subsequent development of cranial structures, such as the oral jaws, suspensorium, neurocranium, hyoid and branchial arches and the opercular apparatus enables the larvae, at 16 dah, to switch from ram feeding to suction feeding on live prey. The use of live Artemia nauplii from 4 to 16 dah is therefore appropriate. The first morphological asymmetries developed at 16 dah in the dentaries and at 22 dah the maxillae and the premaxillae began to show asymmetries. Teeth were present only on the blind side of the oral jaw elements and during this period (16 to 22 dah) the existing elements began to ossify. From 16 to 35 dah the standard feeding protocol consists of a combination of pelagic (Artemia metanauplii) and benthic prey (dead, frozen Artemia nauplii) and from 25 dah onwards a sinking pellet is provided. The time (dah) at which frozen Artemia and sinking pellets were provided, appropriately corresponded to the initiation of benthic feeding behaviour. However at this stage the use of pelagic Artemia metanauplii is inappropriate and unnecessary. At 31 dah the cranial morphology resembled that of adult fish. Adult D. marginatus display extreme asymmetries among the elements of the oral jaws, the suspensorium and certain elements of the neurocranium. Elements on the blind side are larger and more robust than those on the ocular side and are adapted for feeding, while those on the ocular side appear to have a respiratory function. From 31 dah the cranial elements are identical to those of adult fish, suggesting that no further feeding behavioural changes occurred and that a sinking pellet, of which the nutrient composition meets the requirements of the fish, would be appropriate for ongrowing.
- Full Text:
- Date Issued: 2008
Structure and interaction studies of beta-amyloid in the search for new lead compounds for the treatment of Alzheimer’s disease
- Authors: Mtini, Onke
- Date: 2020
- Subjects: Alzheimer's disease -- Chemotherapy , Alzheimer's disease -- Treatment , Amyloid beta-protein , Oxidative stress , Protein binding , South African Natural Compounds Database
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/167574 , vital:41493
- Description: Alzheimer’s disease (AD) is the most devastating neurodegenerative disorder that effects the aging population worldwide. In this study three hypotheses of AD are explored, the β-amyloid cascade hypothesis, the β-amyloid metal binding hypothesis and the oxidative stress hypothesis are explored. In the first case compounds from the South African Natural Compounds Database (SANCDB) are docked to models of β-amyloid fibrils and the properties of these fibrils under pulling simulations are compared to a known small molecule disruptor of β-amyloid, wgx-50. In these simulations SANCDB compounds are identified that disrupt β-amyloid in a similar manner to wgx-50. In these simulations the disruption to the free energy of binding of chains to the fibrils is quantified. For metal binding and oxidative stress hypotheses, problems in simulation arise due to only fragments of β-amyloid being present in the Research Collaboratory for Structural Bioinformatics protein data bank (RCSB PDB), as determined from NMR experiments. In this work, β-amyloid is set up under periodic boundary conditions to simulate a fibril under reasonable computational time. Within these periodic boundary conditions, β-amyloid has been solvated in copper and zinc rich environments and diffusion of these metals around the fibrils has been explored. The localization of these metals (in simulation only using van der Waal’s and electrostatic terms) around the fibril has led us to explore other possible metal binding sites. Metal bound to the infinite fibril has been optimized at the QM/MM level and some of the reactive oxygen species in the presence of the fibril are quantified.
- Full Text:
- Date Issued: 2020
- Authors: Mtini, Onke
- Date: 2020
- Subjects: Alzheimer's disease -- Chemotherapy , Alzheimer's disease -- Treatment , Amyloid beta-protein , Oxidative stress , Protein binding , South African Natural Compounds Database
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/167574 , vital:41493
- Description: Alzheimer’s disease (AD) is the most devastating neurodegenerative disorder that effects the aging population worldwide. In this study three hypotheses of AD are explored, the β-amyloid cascade hypothesis, the β-amyloid metal binding hypothesis and the oxidative stress hypothesis are explored. In the first case compounds from the South African Natural Compounds Database (SANCDB) are docked to models of β-amyloid fibrils and the properties of these fibrils under pulling simulations are compared to a known small molecule disruptor of β-amyloid, wgx-50. In these simulations SANCDB compounds are identified that disrupt β-amyloid in a similar manner to wgx-50. In these simulations the disruption to the free energy of binding of chains to the fibrils is quantified. For metal binding and oxidative stress hypotheses, problems in simulation arise due to only fragments of β-amyloid being present in the Research Collaboratory for Structural Bioinformatics protein data bank (RCSB PDB), as determined from NMR experiments. In this work, β-amyloid is set up under periodic boundary conditions to simulate a fibril under reasonable computational time. Within these periodic boundary conditions, β-amyloid has been solvated in copper and zinc rich environments and diffusion of these metals around the fibrils has been explored. The localization of these metals (in simulation only using van der Waal’s and electrostatic terms) around the fibril has led us to explore other possible metal binding sites. Metal bound to the infinite fibril has been optimized at the QM/MM level and some of the reactive oxygen species in the presence of the fibril are quantified.
- Full Text:
- Date Issued: 2020
Narratiewe strategieë by die ondersoek van die verlede in twee romans, naamlik Lijken op liefde (1997) deur Astrid H. Roemer en Duiwelskloof (1998) deur André P. Brink
- Authors: Potgieter, Maretha
- Date: 2002
- Subjects: Roemer, Astrid. Lijken op liefde , Brink, André Philippus, 1935- Duiwelskloof
- Language: Afrikaans
- Type: Thesis , Masters , MA
- Identifier: vital:3578 , http://hdl.handle.net/10962/d1002151 , Roemer, Astrid. Lijken op liefde , Brink, André Philippus, 1935- Duiwelskloof
- Description: This study investigates some of the narrative strategies used by two novels, namely Lijken op Liefde (1997) by the Surinam born author Astrid H. Roemer and Duiwelskloof (1998) by the South African André P. Brink, in their exploration of and dialogue with traumatic pasts. Both texts are written within so-called postcolonial time frames, delve into the personal and collective past and attempt to provide a corrective on knowledges that used to be deemed not useful, unimportant or have been forgotten by official historiography. The theoretical base of the study is an eclectic mixture of both postcolonial and postmodern theories, throwing light on the strategies employed by these novels in order to understand, problematise and creatively exploit the past. , Hierdie studie kyk na sommige van die narratiewe strategieë binne twee romans, naamlik Lijken op Liefde (1997) deur die Surinaams-gebore outeur Astrid H. Roemer en Duiwelskloof (1998) deur die Suid-Afrikaner André P. Brink, in hulle ondersoek na en dialoog met die traumatiese verlede. Beide tekste is geskryf binne sogenaamde postkoloniale tydvakke, delf in die persoonlike en kollektiewe verlede, en verskaf ’n korrektief op die dinge wat as onbruikbaar of onbelangrik beskou is, of vergete geraak het binne die offisiële historiografie. Die teoretiese basis van die studie is ’n eklektiese mengsel van beide postkoloniale en postmoderne teorieë wat lig werp op die strategieë wat hierdie tekste gebruik om die verlede te verstaan, te problematiseer en kreatief te ontgin.
- Full Text:
- Date Issued: 2002
- Authors: Potgieter, Maretha
- Date: 2002
- Subjects: Roemer, Astrid. Lijken op liefde , Brink, André Philippus, 1935- Duiwelskloof
- Language: Afrikaans
- Type: Thesis , Masters , MA
- Identifier: vital:3578 , http://hdl.handle.net/10962/d1002151 , Roemer, Astrid. Lijken op liefde , Brink, André Philippus, 1935- Duiwelskloof
- Description: This study investigates some of the narrative strategies used by two novels, namely Lijken op Liefde (1997) by the Surinam born author Astrid H. Roemer and Duiwelskloof (1998) by the South African André P. Brink, in their exploration of and dialogue with traumatic pasts. Both texts are written within so-called postcolonial time frames, delve into the personal and collective past and attempt to provide a corrective on knowledges that used to be deemed not useful, unimportant or have been forgotten by official historiography. The theoretical base of the study is an eclectic mixture of both postcolonial and postmodern theories, throwing light on the strategies employed by these novels in order to understand, problematise and creatively exploit the past. , Hierdie studie kyk na sommige van die narratiewe strategieë binne twee romans, naamlik Lijken op Liefde (1997) deur die Surinaams-gebore outeur Astrid H. Roemer en Duiwelskloof (1998) deur die Suid-Afrikaner André P. Brink, in hulle ondersoek na en dialoog met die traumatiese verlede. Beide tekste is geskryf binne sogenaamde postkoloniale tydvakke, delf in die persoonlike en kollektiewe verlede, en verskaf ’n korrektief op die dinge wat as onbruikbaar of onbelangrik beskou is, of vergete geraak het binne die offisiële historiografie. Die teoretiese basis van die studie is ’n eklektiese mengsel van beide postkoloniale en postmoderne teorieë wat lig werp op die strategieë wat hierdie tekste gebruik om die verlede te verstaan, te problematiseer en kreatief te ontgin.
- Full Text:
- Date Issued: 2002
Issues and challenges facing school libraries: a case study of selected primary schools in Gauteng Province, South Africa
- Paton-Ash, Margaret Sanderson
- Authors: Paton-Ash, Margaret Sanderson
- Date: 2012
- Subjects: School libraries -- South Africa -- Gauteng Libraries and state -- South Africa -- Gauteng Libraries and schools -- South Africa -- Gauteng Library planning -- South Africa -- Gauteng Libraries and education -- South Africa -- Gauteng
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1660 , http://hdl.handle.net/10962/d1003543
- Description: Fewer than 8% of schools in South Africa have functioning libraries. There is no national policy for school libraries which compels School Governing Bodies and principals to have a library in their schools. This qualitative study, based on grounded theory, investigated ten primary schools in Gauteng that had libraries, or were in the process of setting up a library with the intention of providing a rich description of the issues and challenges facing these schools. The schools were chosen on the basis of location (Soweto and Johannesburg), and the school fees that were paid in a continuum from low/no fee paying schools to the fee paying ex Model-C schools. The resourcing of the school library, the operation of the school library and the role of the library were examined. The findings highlight the lack of a national policy, of school library posts, the theft of computers as a result of the lack of security, as well as the lack of understanding by teachers of the role the library in teaching and learning. Furthermore, there appears to be a disjuncture between the trends evident in the international literature on school libraries and what is actually happening in the primary school libraries in my study. Most significantly low/no fee paying schools with libraries were the exception and those that did have libraries were as a result of the enthusiasm and efforts of one or two individuals with the backing of the principal. Ex-Model C schools had the advantage in terms of the provision and staffing of school libraries as they had the funds to support them and, in some cases, a school librarian, provided that the principal supported the idea of a school library. In all the schools, the belief in the importance of the library regarding reading and literacy was the main motivating factor in establishing or maintaining the school library. A growing public awareness of the value of school libraries was an encouraging trend that emerged from my study.
- Full Text:
- Date Issued: 2012
- Authors: Paton-Ash, Margaret Sanderson
- Date: 2012
- Subjects: School libraries -- South Africa -- Gauteng Libraries and state -- South Africa -- Gauteng Libraries and schools -- South Africa -- Gauteng Library planning -- South Africa -- Gauteng Libraries and education -- South Africa -- Gauteng
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1660 , http://hdl.handle.net/10962/d1003543
- Description: Fewer than 8% of schools in South Africa have functioning libraries. There is no national policy for school libraries which compels School Governing Bodies and principals to have a library in their schools. This qualitative study, based on grounded theory, investigated ten primary schools in Gauteng that had libraries, or were in the process of setting up a library with the intention of providing a rich description of the issues and challenges facing these schools. The schools were chosen on the basis of location (Soweto and Johannesburg), and the school fees that were paid in a continuum from low/no fee paying schools to the fee paying ex Model-C schools. The resourcing of the school library, the operation of the school library and the role of the library were examined. The findings highlight the lack of a national policy, of school library posts, the theft of computers as a result of the lack of security, as well as the lack of understanding by teachers of the role the library in teaching and learning. Furthermore, there appears to be a disjuncture between the trends evident in the international literature on school libraries and what is actually happening in the primary school libraries in my study. Most significantly low/no fee paying schools with libraries were the exception and those that did have libraries were as a result of the enthusiasm and efforts of one or two individuals with the backing of the principal. Ex-Model C schools had the advantage in terms of the provision and staffing of school libraries as they had the funds to support them and, in some cases, a school librarian, provided that the principal supported the idea of a school library. In all the schools, the belief in the importance of the library regarding reading and literacy was the main motivating factor in establishing or maintaining the school library. A growing public awareness of the value of school libraries was an encouraging trend that emerged from my study.
- Full Text:
- Date Issued: 2012
A discourse analysis of print media constructions of 'Muslim' people in British newspapers
- Authors: Nanabawa, Sumaiya
- Date: 2013
- Subjects: Muslims -- Great Britain -- Public opinion Islam -- Great Britain -- Public opinion Racism in mass media Mass media -- Political aspects -- Great Britain Mass media -- Social aspects -- Great Britain Journalism -- Social aspects Journalism, Commercial -- Great Britain
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3132 , http://hdl.handle.net/10962/d1006767
- Description: This research study aimed to examine how the identity of ' Muslim' people is constructed in British print media today, and whether or not these constructions promote or undermine a xeno-racist project. The research draws on the idea that identity is partly constructed through representation, with an emphasis on how language can be used to construct and position people in different ways. Using a social constructionist paradigm, the study further considers the role that print media has in providing a discursive field within which the construction and reproduction of racist attitudes and ideologies in contemporary global society can take place. Sixty-five newspaper articles were selected from the online archives of British newspapers, The Guardian and The Daily Telegraph using systematic random sampling. These were analysed using the six stages of Foucauldian discourse analysis outlined by Carla Willig. To provide a more fruitful account, the analysis also incorporated the methods of Potter and Wetherell whose focus is on the function of discourse, as well as van Langenhove and Harre's focus on subject positioning, and Parker's use of Foucauldian analysis which looks at power distributions. The analysis revealed that Muslims are discursively constructed as a direct politicised or terror threat, often drawing on discourses of sharia law, and Muslim-Christian relationships. They are also constructed as a cultural threat, drawing on discourses of isolation, oppressed women, the veil/headscarf, identity, visibility and integration. The analysis also showed some variation in constructions, and these extended from the racialization of Muslims to showing the compatibility between Islamic and western values. This study discusses the form these different constructions take and the possible implications these constructions might have in contributing toward a prejudiced and largely negative image of Islam and Muslims.
- Full Text:
- Date Issued: 2013
- Authors: Nanabawa, Sumaiya
- Date: 2013
- Subjects: Muslims -- Great Britain -- Public opinion Islam -- Great Britain -- Public opinion Racism in mass media Mass media -- Political aspects -- Great Britain Mass media -- Social aspects -- Great Britain Journalism -- Social aspects Journalism, Commercial -- Great Britain
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3132 , http://hdl.handle.net/10962/d1006767
- Description: This research study aimed to examine how the identity of ' Muslim' people is constructed in British print media today, and whether or not these constructions promote or undermine a xeno-racist project. The research draws on the idea that identity is partly constructed through representation, with an emphasis on how language can be used to construct and position people in different ways. Using a social constructionist paradigm, the study further considers the role that print media has in providing a discursive field within which the construction and reproduction of racist attitudes and ideologies in contemporary global society can take place. Sixty-five newspaper articles were selected from the online archives of British newspapers, The Guardian and The Daily Telegraph using systematic random sampling. These were analysed using the six stages of Foucauldian discourse analysis outlined by Carla Willig. To provide a more fruitful account, the analysis also incorporated the methods of Potter and Wetherell whose focus is on the function of discourse, as well as van Langenhove and Harre's focus on subject positioning, and Parker's use of Foucauldian analysis which looks at power distributions. The analysis revealed that Muslims are discursively constructed as a direct politicised or terror threat, often drawing on discourses of sharia law, and Muslim-Christian relationships. They are also constructed as a cultural threat, drawing on discourses of isolation, oppressed women, the veil/headscarf, identity, visibility and integration. The analysis also showed some variation in constructions, and these extended from the racialization of Muslims to showing the compatibility between Islamic and western values. This study discusses the form these different constructions take and the possible implications these constructions might have in contributing toward a prejudiced and largely negative image of Islam and Muslims.
- Full Text:
- Date Issued: 2013
Normative indicators for an isiXhosa-speaking population with disadvantaged education for tests of hand motor function and verbal fluency
- Authors: Da Silva Pita, Anita
- Date: 2012
- Subjects: Neuropsychological tests Hand -- Movements People with social disabilities -- Language People with social disabilities -- Education
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2959 , http://hdl.handle.net/10962/d1002468
- Description: The aim of the study was to obtain preliminary normative data for two tests of hand motor function (Successive Finger Tapping and Purdue Pegboard tests) and two tests of verbal fluency ("S"-Words-In-One-Minute and Words-In-One-Minute), administered in English, on a non-clinical sample of black, isiXhosa-speaking unskilled workers with a background of relatively disadvantaged former DET education (N = 33). The sample was equally distributed for gender; educational level was restricted to 11 - 12 years; age range was 18 - 40 years divided further into two age categories (18 - 29 and 30 - 40 years). Results of t-test comparative analyses revealed significant age effects on both trials of the Successive Finger Tapping test in the direction of the younger age group outperforming the older age group, and a marginal but consistent tendency towards poorer performance at an earlier age stage than proposed by the available literature, for the Purdue Pegboard, "S"Words- In-One-Minute and Words-In-One-Minute. Gender effects were only in evidence on the Purdue Pegboard in the direction of females outperforming males. A descriptive comparison of the norms acquired for the present study with available normative data for English first language speaking populations with higher levels and/ or relatively advantaged quality of education revealed consistently poorer performance for the present study. The findings highlight the effect of relatively low levels and/ or poor quality of education on both verbal and non-verbal neuropsychological test performance and confirm the need for demographically specific normative data.
- Full Text:
- Date Issued: 2012
- Authors: Da Silva Pita, Anita
- Date: 2012
- Subjects: Neuropsychological tests Hand -- Movements People with social disabilities -- Language People with social disabilities -- Education
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2959 , http://hdl.handle.net/10962/d1002468
- Description: The aim of the study was to obtain preliminary normative data for two tests of hand motor function (Successive Finger Tapping and Purdue Pegboard tests) and two tests of verbal fluency ("S"-Words-In-One-Minute and Words-In-One-Minute), administered in English, on a non-clinical sample of black, isiXhosa-speaking unskilled workers with a background of relatively disadvantaged former DET education (N = 33). The sample was equally distributed for gender; educational level was restricted to 11 - 12 years; age range was 18 - 40 years divided further into two age categories (18 - 29 and 30 - 40 years). Results of t-test comparative analyses revealed significant age effects on both trials of the Successive Finger Tapping test in the direction of the younger age group outperforming the older age group, and a marginal but consistent tendency towards poorer performance at an earlier age stage than proposed by the available literature, for the Purdue Pegboard, "S"Words- In-One-Minute and Words-In-One-Minute. Gender effects were only in evidence on the Purdue Pegboard in the direction of females outperforming males. A descriptive comparison of the norms acquired for the present study with available normative data for English first language speaking populations with higher levels and/ or relatively advantaged quality of education revealed consistently poorer performance for the present study. The findings highlight the effect of relatively low levels and/ or poor quality of education on both verbal and non-verbal neuropsychological test performance and confirm the need for demographically specific normative data.
- Full Text:
- Date Issued: 2012
Black university students’ experiences of negotiating their social identity in a historically white university
- Authors: Mogotsi, Opelo Petunia
- Date: 2018
- Subjects: Corporate culture -- South Africa , Social integration -- South Africa , Race discrimination -- South Africa , Segregation in higher education -- South Africa , Group identity -- South Africa , College students, Black -- South Africa , Biko, Steve, 1946-1977 , Fanon, Frantz, 1925-1961
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/62416 , vital:28174
- Description: This thesis seeks to explore the social identity of black students in a historically white university. Since 1994, South African government has been promulgating pieces of legislation aimed at ensuring racial integration, and indirectly enforcing acculturation in historically white universities. Studies have proven that institutional cultures in historically white universities alienate and exclude black students’ identities. These students’ sense of social identity, which includes amongst others; culture, heritage, language and traditions, and consequently self-esteem and self-concept is altered in these institutions. Research has been scant regarding the shape and form that black students’ identity assume when they get to these spaces. Face to face interviews were used to collect data and thematic analysis was used for data analysis. The Social Identity and the Acculturation models were used to explore the experiences of black students in negotiating their social identities in a historically white university. Evoking Steve Biko’s analysis of ‘artificial integration’, it was illustrated how the ‘integration’ narrative sought to discard the identity of black students and psychologically enforce a simulation of black students into white established identities. The main themes discussed indicated that black students in this study had social identity and identity challenges in a historically white university. This study has implications for policy development as I hope to theoretically sensitize historically white universities to (apart from mere opening of spaces of learning) understand the social identity challenges of black students.
- Full Text:
- Date Issued: 2018
- Authors: Mogotsi, Opelo Petunia
- Date: 2018
- Subjects: Corporate culture -- South Africa , Social integration -- South Africa , Race discrimination -- South Africa , Segregation in higher education -- South Africa , Group identity -- South Africa , College students, Black -- South Africa , Biko, Steve, 1946-1977 , Fanon, Frantz, 1925-1961
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/62416 , vital:28174
- Description: This thesis seeks to explore the social identity of black students in a historically white university. Since 1994, South African government has been promulgating pieces of legislation aimed at ensuring racial integration, and indirectly enforcing acculturation in historically white universities. Studies have proven that institutional cultures in historically white universities alienate and exclude black students’ identities. These students’ sense of social identity, which includes amongst others; culture, heritage, language and traditions, and consequently self-esteem and self-concept is altered in these institutions. Research has been scant regarding the shape and form that black students’ identity assume when they get to these spaces. Face to face interviews were used to collect data and thematic analysis was used for data analysis. The Social Identity and the Acculturation models were used to explore the experiences of black students in negotiating their social identities in a historically white university. Evoking Steve Biko’s analysis of ‘artificial integration’, it was illustrated how the ‘integration’ narrative sought to discard the identity of black students and psychologically enforce a simulation of black students into white established identities. The main themes discussed indicated that black students in this study had social identity and identity challenges in a historically white university. This study has implications for policy development as I hope to theoretically sensitize historically white universities to (apart from mere opening of spaces of learning) understand the social identity challenges of black students.
- Full Text:
- Date Issued: 2018
Synthesis of silver nanoparticles and their role against human and Plasmodium falciparum leucine aminopeptidase
- Authors: Mnkandhla, Dumisani
- Date: 2015
- Subjects: Silver , Nanoparticles , Plasmodium falciparum , Leucine aminopeptidase , Antimalarials , Nanotechnology
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4150 , http://hdl.handle.net/10962/d1017911
- Description: Antimalarial drug discovery remains a challenging endeavour as malaria parasites continue to develop resistance to drugs, including those which are currently the last line of defence against the disease. Plasmodium falciparum is the most virulent of the malaria parasites and it delivers its deadliest impact during the erythrocytic stages of the parasite’s life cycle; a stage characterised by elevated catabolism of haemoglobin and anabolism of parasite proteins. The present study investigates the use of nanotechnology in the form of metallic silver nanoparticles (AgNPs) against P. falciparum leucine aminopeptidase (PfLAP), a validated biomedical target involved in haemoglobin metabolism. AgNPs were also tested against the human homolog cytosolic Homo sapiens leucine aminopeptidase (HsLAP) to ascertain their selective abilities. PfLAP and HsLAP were successfully expressed in Escherichia coli BL21(DE3) cells. PfLAP showed optimal thermal stability at 25 °C and optimal pH stability at pH 8.0 with a Km of 42.7 mM towards leucine-p-nitroanilide (LpNA) and a Vmax of 59.9 μmol.ml⁻¹.min⁻¹. HsLAP was optimally stable at 37 °C and at pH 7.0 with a Km of 16.7 mM and a Vmax of 17.2 μmol.ml⁻¹.min⁻¹. Both enzymes exhibited optimal activity in the presence of 2 mM Mn²⁺. On interaction with polyvinylpyrrolidone (PVP) stabilised AgNPs, both enzymes were inhibited to differing extents with PfLAP losing three fold of its catalytic efficiency relative to HsLAP. These results show the ability of AgNPs to selectively inhibit PfLAP whilst having much lesser effects on its human homolog. With the use of available targeting techniques, the present study shows the potential use of nanotechnology based approaches as “silver bullets” that can target PfLAP without adversely affecting the host. However further research needs to be conducted to better understand the mechanisms of AgNP action, drug targeting and the health and safety issues associated with nanotechnology use.
- Full Text:
- Date Issued: 2015
- Authors: Mnkandhla, Dumisani
- Date: 2015
- Subjects: Silver , Nanoparticles , Plasmodium falciparum , Leucine aminopeptidase , Antimalarials , Nanotechnology
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4150 , http://hdl.handle.net/10962/d1017911
- Description: Antimalarial drug discovery remains a challenging endeavour as malaria parasites continue to develop resistance to drugs, including those which are currently the last line of defence against the disease. Plasmodium falciparum is the most virulent of the malaria parasites and it delivers its deadliest impact during the erythrocytic stages of the parasite’s life cycle; a stage characterised by elevated catabolism of haemoglobin and anabolism of parasite proteins. The present study investigates the use of nanotechnology in the form of metallic silver nanoparticles (AgNPs) against P. falciparum leucine aminopeptidase (PfLAP), a validated biomedical target involved in haemoglobin metabolism. AgNPs were also tested against the human homolog cytosolic Homo sapiens leucine aminopeptidase (HsLAP) to ascertain their selective abilities. PfLAP and HsLAP were successfully expressed in Escherichia coli BL21(DE3) cells. PfLAP showed optimal thermal stability at 25 °C and optimal pH stability at pH 8.0 with a Km of 42.7 mM towards leucine-p-nitroanilide (LpNA) and a Vmax of 59.9 μmol.ml⁻¹.min⁻¹. HsLAP was optimally stable at 37 °C and at pH 7.0 with a Km of 16.7 mM and a Vmax of 17.2 μmol.ml⁻¹.min⁻¹. Both enzymes exhibited optimal activity in the presence of 2 mM Mn²⁺. On interaction with polyvinylpyrrolidone (PVP) stabilised AgNPs, both enzymes were inhibited to differing extents with PfLAP losing three fold of its catalytic efficiency relative to HsLAP. These results show the ability of AgNPs to selectively inhibit PfLAP whilst having much lesser effects on its human homolog. With the use of available targeting techniques, the present study shows the potential use of nanotechnology based approaches as “silver bullets” that can target PfLAP without adversely affecting the host. However further research needs to be conducted to better understand the mechanisms of AgNP action, drug targeting and the health and safety issues associated with nanotechnology use.
- Full Text:
- Date Issued: 2015
Governance and management of urban trees and green spaces in South Africa: ensuring benefits to local people and the environment
- Authors: Chishaleshale, Mwale
- Date: 2013
- Subjects: Trees in cities -- South Africa , Urban forestry -- South Africa , Community forestry -- South Africa , City planning -- South Africa , Human-plant relationships -- South Africa , Urban ecology (Biology -- South Africa , Urban ecology (Sociology) -- South Africa , Natural resources -- South Africa , Trees in cities -- Law and legislation -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4739 , http://hdl.handle.net/10962/d1006035 , Trees in cities -- South Africa , Urban forestry -- South Africa , Community forestry -- South Africa , City planning -- South Africa , Human-plant relationships -- South Africa , Urban ecology (Biology -- South Africa , Urban ecology (Sociology) -- South Africa , Natural resources -- South Africa , Trees in cities -- Law and legislation -- South Africa
- Description: In the face of rapid urbanization and global climate change, urban trees and green spaces (UTGS) can contribute to the welfare of people and the urban environment. Urban trees and green spaces can assist to address urbanization challenges related to environmental degradation. While functions of UTGS have been well documented in the developed world, they have not yet received full attention in much of sub-Saharan Africa. Consequently, UTGS are under threat from urban development and fragmentation. Notably, the problems associated with UTGS also fall into the governance realm and indications are that poor governance and management of UTGS can negatively influence the potential benefits of UTGS to local people and the environment. This formed a basis for this research. The main objective of the study was to determine the current governance and management approaches to UTGS in South Africa. Through document search and review, the study determined the governance institutions influencing UTGS at national level and at provincial level (in the Limpopo and Eastern Cape Provinces). Face-to-face and online survey methods were used to determine the extent to which 28 local municipalities had adopted planned, systematic and integrated management of UTGS. The snowball approach was used to determine the key actors involved in UTGS activities and interviews were conducted to establish the roles and capabilities of these actors. A total of 540 household interviews were conducted to determine the institutional factors influencing local peoples’ ability to access, plant and use UTGS. The findings of the study showed that UTGS have not been adequately covered in existing governance institutions and practice at national and provincial levels. Local government municipalities were not managing their UTGS in a planned or systematic manner due to constraining factors such as insufficient funds, insufficient personnel, lack of equipment and lack of political support. Only 7.1 % of the surveyed municipalities had an urban tree management plan and an estimate of the urban tree stock; 32.1 % had tree policies; 28.6 % had tree bylaws; 21.4 % had tree planting schedules; 10.7 % had tree maintenance schedules and only 3.6 % had tree inspection schedules. Key actors involved in UTGS activities differed among levels of government. The actors included national and provincial government departments, local government municipalities, Non-Governmental Organizations, private sector companies and local volunteers. Most of the actors, however, either planted trees or provided tree seedlings to municipalities and the local people. Tenure security was a key institutional factor affecting peoples’ ability to plant, use or even remove trees from their residential plots. The same applied to trees in the streets and public parks. Whereas most respondents did not require permission to plant (79.8 %) or remove (75 %) trees on their residential plots, a majority of them required permission to plant and remove trees from streets (over 70 %) and public parks (over 80 %). However, with regard to planting and removing urban trees in public open spaces, 54% of the respondents indicated that permission was not required suggesting a lack of clarity among local residents on the issue. Overall, the findings of this study indicate that there is no political recognition and support for UTGS at almost all levels of government. This has resulted in the lack of incorporation of UTGS in urban planning and development and has caused UTGS to receive limited funding to permit planned and systematic management. Given the current rates of urbanization and urban development, the lowly prioritised UTGS are vulnerable to exploitation. To conserve UTGS and promote their potential contribution to local people and the environment, UTGS must be recognized and placed on political and development agendas. There is a need to develop national guidelines for UTGS management, assess the extent of the urban forest resource in local municipalities, clearly define the roles and capabilities of different actors, integrate UTGS in the urban planning and development system, and most of all seek to involve the local people in overall management and governance of UTGS.
- Full Text:
- Date Issued: 2013
- Authors: Chishaleshale, Mwale
- Date: 2013
- Subjects: Trees in cities -- South Africa , Urban forestry -- South Africa , Community forestry -- South Africa , City planning -- South Africa , Human-plant relationships -- South Africa , Urban ecology (Biology -- South Africa , Urban ecology (Sociology) -- South Africa , Natural resources -- South Africa , Trees in cities -- Law and legislation -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4739 , http://hdl.handle.net/10962/d1006035 , Trees in cities -- South Africa , Urban forestry -- South Africa , Community forestry -- South Africa , City planning -- South Africa , Human-plant relationships -- South Africa , Urban ecology (Biology -- South Africa , Urban ecology (Sociology) -- South Africa , Natural resources -- South Africa , Trees in cities -- Law and legislation -- South Africa
- Description: In the face of rapid urbanization and global climate change, urban trees and green spaces (UTGS) can contribute to the welfare of people and the urban environment. Urban trees and green spaces can assist to address urbanization challenges related to environmental degradation. While functions of UTGS have been well documented in the developed world, they have not yet received full attention in much of sub-Saharan Africa. Consequently, UTGS are under threat from urban development and fragmentation. Notably, the problems associated with UTGS also fall into the governance realm and indications are that poor governance and management of UTGS can negatively influence the potential benefits of UTGS to local people and the environment. This formed a basis for this research. The main objective of the study was to determine the current governance and management approaches to UTGS in South Africa. Through document search and review, the study determined the governance institutions influencing UTGS at national level and at provincial level (in the Limpopo and Eastern Cape Provinces). Face-to-face and online survey methods were used to determine the extent to which 28 local municipalities had adopted planned, systematic and integrated management of UTGS. The snowball approach was used to determine the key actors involved in UTGS activities and interviews were conducted to establish the roles and capabilities of these actors. A total of 540 household interviews were conducted to determine the institutional factors influencing local peoples’ ability to access, plant and use UTGS. The findings of the study showed that UTGS have not been adequately covered in existing governance institutions and practice at national and provincial levels. Local government municipalities were not managing their UTGS in a planned or systematic manner due to constraining factors such as insufficient funds, insufficient personnel, lack of equipment and lack of political support. Only 7.1 % of the surveyed municipalities had an urban tree management plan and an estimate of the urban tree stock; 32.1 % had tree policies; 28.6 % had tree bylaws; 21.4 % had tree planting schedules; 10.7 % had tree maintenance schedules and only 3.6 % had tree inspection schedules. Key actors involved in UTGS activities differed among levels of government. The actors included national and provincial government departments, local government municipalities, Non-Governmental Organizations, private sector companies and local volunteers. Most of the actors, however, either planted trees or provided tree seedlings to municipalities and the local people. Tenure security was a key institutional factor affecting peoples’ ability to plant, use or even remove trees from their residential plots. The same applied to trees in the streets and public parks. Whereas most respondents did not require permission to plant (79.8 %) or remove (75 %) trees on their residential plots, a majority of them required permission to plant and remove trees from streets (over 70 %) and public parks (over 80 %). However, with regard to planting and removing urban trees in public open spaces, 54% of the respondents indicated that permission was not required suggesting a lack of clarity among local residents on the issue. Overall, the findings of this study indicate that there is no political recognition and support for UTGS at almost all levels of government. This has resulted in the lack of incorporation of UTGS in urban planning and development and has caused UTGS to receive limited funding to permit planned and systematic management. Given the current rates of urbanization and urban development, the lowly prioritised UTGS are vulnerable to exploitation. To conserve UTGS and promote their potential contribution to local people and the environment, UTGS must be recognized and placed on political and development agendas. There is a need to develop national guidelines for UTGS management, assess the extent of the urban forest resource in local municipalities, clearly define the roles and capabilities of different actors, integrate UTGS in the urban planning and development system, and most of all seek to involve the local people in overall management and governance of UTGS.
- Full Text:
- Date Issued: 2013
The concept of "the people" in liberation theology
- Authors: Menatsi, Richard
- Date: 1994
- Subjects: Liberation theology , Poor -- Religious aspects , Poverty -- Religious aspects -- Christianity , Government, Resistance to -- Religious aspects -- Christianity
- Language: English
- Type: Thesis , Masters , MTh
- Identifier: vital:1297 , http://hdl.handle.net/10962/d1015654
- Description: The concept of "the people" has become a key concept within the work of several Latin American theologians, Korean Minjung theologians and South African theologians. When liberation theologians use the concept of "the people" in their literature they do so with a lack of clarity, to the extent that the exact meaning of the term is obscure. In their usage of the concept "the people" liberation theologians come up with differing and at times contradictory meanings, particularly as regards the concrete and symbolic meanings of the concept. This thesis sets out to investigate the use of the concept "the people" by liberation theologians by consulting a selection from Latin American theology, Korean Minjung theology, South African liberation theology and Marxism, to detect its influence on the use of this notion. A general overview of the thesis indicates the following. The first chapter provides a detailed analysis of the concept of "the people" in the work of different liberation theologians. Chapter two considers "the people" in relation to poverty and oppression. The third chapter deals with "the people" as subjects of history. In the fourth chapter "the people" as a concept is developed in relation to belief within the Christian church. The final chapter is an evaluation. The thesis reveals that the following characteristics are central to "the people", they are poor and oppressed but are also inclusive of all those persons who identify and actively support the struggle against poverty and oppression. "The people" are subjects of their own history, finally they are Christian believers.
- Full Text:
- Date Issued: 1994
- Authors: Menatsi, Richard
- Date: 1994
- Subjects: Liberation theology , Poor -- Religious aspects , Poverty -- Religious aspects -- Christianity , Government, Resistance to -- Religious aspects -- Christianity
- Language: English
- Type: Thesis , Masters , MTh
- Identifier: vital:1297 , http://hdl.handle.net/10962/d1015654
- Description: The concept of "the people" has become a key concept within the work of several Latin American theologians, Korean Minjung theologians and South African theologians. When liberation theologians use the concept of "the people" in their literature they do so with a lack of clarity, to the extent that the exact meaning of the term is obscure. In their usage of the concept "the people" liberation theologians come up with differing and at times contradictory meanings, particularly as regards the concrete and symbolic meanings of the concept. This thesis sets out to investigate the use of the concept "the people" by liberation theologians by consulting a selection from Latin American theology, Korean Minjung theology, South African liberation theology and Marxism, to detect its influence on the use of this notion. A general overview of the thesis indicates the following. The first chapter provides a detailed analysis of the concept of "the people" in the work of different liberation theologians. Chapter two considers "the people" in relation to poverty and oppression. The third chapter deals with "the people" as subjects of history. In the fourth chapter "the people" as a concept is developed in relation to belief within the Christian church. The final chapter is an evaluation. The thesis reveals that the following characteristics are central to "the people", they are poor and oppressed but are also inclusive of all those persons who identify and actively support the struggle against poverty and oppression. "The people" are subjects of their own history, finally they are Christian believers.
- Full Text:
- Date Issued: 1994
Understanding development aid and state autonomy : the case of European Union budget support to Mozambique
- Authors: Ndlovu, Ana Admiração
- Date: 2014
- Subjects: Economic assistance, European -- Mozambique , Economic development -- Mozambique , Mozambique -- Economic conditions , Autonomy , Budget -- Mozambique
- Language: English
- Type: Thesis , Masters , MSocSc
- Identifier: vital:3378 , http://hdl.handle.net/10962/d1013218
- Description: Post-colonial states in Africa continue to pursue nation-building and socio-economic development. This process is taking place with the sustained support of global agencies in terms of development cooperation, assistance and aid. Insofar as an endogenous development path which speaks to national priorities can be formulated and implemented by post-colonial states, their relationship with these agencies raises serious questions about such a path if the relationship entails dependence and indeed subordination of post-colonial states. This raises important questions about state autonomy under post-colonial conditions and the possibility of autonomy being compromised. In this light, the thesis examines European Union budget support to Mozambique and, in particular, the relationship between EU budget support and Mozambique state autonomy in pursuing national development. This is particularly pertinent given the massive dependence of the Mozambican state on foreign funding (notably EU funding) with specific regard to the national budget. Despite the broad claims existing in the prevailing literature that nation-state autonomy is seriously undermined in and through the international development system, the thesis argues against reductionist arguments that simply posit post-colonial states as mere instruments of global forces. This system, including European Union budget support, does indeed set the conditions of existence for post-colonial states such as Mozambique. But autonomy is necessarily relative and is subject to different forms and degrees. Ultimately, it is through empirical investigation that the specific form and degree of autonomy can be pinpointed and understood. The thesis contributes to this endeavour and suggests that the relationship between European budget support and Mozambican state autonomy is more complex and tension-riddled than the prevailing literature would seem to suggest.
- Full Text:
- Date Issued: 2014
- Authors: Ndlovu, Ana Admiração
- Date: 2014
- Subjects: Economic assistance, European -- Mozambique , Economic development -- Mozambique , Mozambique -- Economic conditions , Autonomy , Budget -- Mozambique
- Language: English
- Type: Thesis , Masters , MSocSc
- Identifier: vital:3378 , http://hdl.handle.net/10962/d1013218
- Description: Post-colonial states in Africa continue to pursue nation-building and socio-economic development. This process is taking place with the sustained support of global agencies in terms of development cooperation, assistance and aid. Insofar as an endogenous development path which speaks to national priorities can be formulated and implemented by post-colonial states, their relationship with these agencies raises serious questions about such a path if the relationship entails dependence and indeed subordination of post-colonial states. This raises important questions about state autonomy under post-colonial conditions and the possibility of autonomy being compromised. In this light, the thesis examines European Union budget support to Mozambique and, in particular, the relationship between EU budget support and Mozambique state autonomy in pursuing national development. This is particularly pertinent given the massive dependence of the Mozambican state on foreign funding (notably EU funding) with specific regard to the national budget. Despite the broad claims existing in the prevailing literature that nation-state autonomy is seriously undermined in and through the international development system, the thesis argues against reductionist arguments that simply posit post-colonial states as mere instruments of global forces. This system, including European Union budget support, does indeed set the conditions of existence for post-colonial states such as Mozambique. But autonomy is necessarily relative and is subject to different forms and degrees. Ultimately, it is through empirical investigation that the specific form and degree of autonomy can be pinpointed and understood. The thesis contributes to this endeavour and suggests that the relationship between European budget support and Mozambican state autonomy is more complex and tension-riddled than the prevailing literature would seem to suggest.
- Full Text:
- Date Issued: 2014
Understanding of the underlying resistance mechanism of the Kat-G protein against isoniazid in Mycobacterium tuberculosis using bioinformatics approaches
- Authors: Barozi, Victor
- Date: 2020
- Subjects: Mycobacterium tuberculosis , Isoniazid , Drug resistance in microorganisms , Proteins -- Microbiology
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/146592 , vital:38540
- Description: Tuberculosis (TB) is a multi-organ infection caused by rod-shaped acid-fast Mycobacterium tuberculosis. The World Health Organization (WHO) ranks TB among the top 10 fatal infections and the leading the cause of death from a single infection. In 2017, TB was responsible for an estimated 1.3 million deaths among both the HIV negative and positive populations worldwide (WHO, 2018). Approximately 23% (roughly 1.7 billion) of the world’s population is estimated to have latent TB with a high risk of reverting to active TB infection. In 2017, an estimated 558,000 people developed drug resistant TB worldwide with 82% of the cases being multi-drug resistant TB (WHO, 2018). South Africa is ranked among the 30 high TB burdened countries with a TB incidence of 322,000 cases in 2017 accounting for 3% of the world’s TB cases. TB is curable and is clinically managed through a combination of intensive and continuation phases of first-line drugs (isoniazid, rifampicin, ethambutol, and pyrazinamide). Second-line drugs which include fluoroquinolones, injectable aminoglycoside and injectable polypeptides are used in cases of first line drug resistance. The third-line drugs include amoxicillin, clofazimine, linezolid and imipenem. These have variable but unproven efficacy to TB and are the last resort in cases of total drug resistance (Jilani et al., 2019). TB drug resistance to first-line drugs especially isoniazid in M. tuberculosis has been attributed to single nucleotide polymorphisms (SNPs) in the catalase peroxidase enzyme (katG), a protein important in the activation of the pro-drug isoniazid. The SNPs especially at position 315 of the katG enzyme are believed to reduce the sensitivity of the M. tuberculosis to isoniazid while still maintaining the enzyme’s catalytic activity - a mechanism not completely understood. KatG protein is important for protecting the bacteria from hydro peroxides and hydroxyl radicals present in an aerobic environment. This study focused on understanding the mechanism of isoniazid drug resistance in M. tuberculosis as a result of high confidence mutations in the katG through modelling the enzyme with its respective variants, performing MD simulations to explore the protein behaviour, calculating the dynamic residue network analysis (DRN) of the variants in respect to the wild type katG and finally performing alanine scanning. From the MD simulations, it was observed that the high confidence mutations i.e. S140R, S140N, G279D, G285D, S315T, S315I, S315R, S315N, G316D, S457I and G593D were not only reducing the backbone flexibility of the protein but also reducing the protein’s conformational variation and space. All the variant protein structures were observed to be more compact compared to the wild type. Residue fluctuation results indicated reduced residue flexibility across all variants in the loop region (position 26-110) responsible for katG dimerization. In addition, mutation S315T is believed to reduce the size of the active site access channel in the protein. From the DRN data, residues in the interface region between the N and C-terminal domains were observed to gain importance in the variants irrespective of the mutation location indicating an allosteric effect of the mutations on the interface region. Alanine scanning results established that residue Leucine at position 48 was not only important in the protein communication but also a destabilizing residue across all the variants. The study not only demonstrated change in the protein behaviour but also showed allosteric effect of the mutations in the katG protein.
- Full Text:
- Date Issued: 2020
- Authors: Barozi, Victor
- Date: 2020
- Subjects: Mycobacterium tuberculosis , Isoniazid , Drug resistance in microorganisms , Proteins -- Microbiology
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/146592 , vital:38540
- Description: Tuberculosis (TB) is a multi-organ infection caused by rod-shaped acid-fast Mycobacterium tuberculosis. The World Health Organization (WHO) ranks TB among the top 10 fatal infections and the leading the cause of death from a single infection. In 2017, TB was responsible for an estimated 1.3 million deaths among both the HIV negative and positive populations worldwide (WHO, 2018). Approximately 23% (roughly 1.7 billion) of the world’s population is estimated to have latent TB with a high risk of reverting to active TB infection. In 2017, an estimated 558,000 people developed drug resistant TB worldwide with 82% of the cases being multi-drug resistant TB (WHO, 2018). South Africa is ranked among the 30 high TB burdened countries with a TB incidence of 322,000 cases in 2017 accounting for 3% of the world’s TB cases. TB is curable and is clinically managed through a combination of intensive and continuation phases of first-line drugs (isoniazid, rifampicin, ethambutol, and pyrazinamide). Second-line drugs which include fluoroquinolones, injectable aminoglycoside and injectable polypeptides are used in cases of first line drug resistance. The third-line drugs include amoxicillin, clofazimine, linezolid and imipenem. These have variable but unproven efficacy to TB and are the last resort in cases of total drug resistance (Jilani et al., 2019). TB drug resistance to first-line drugs especially isoniazid in M. tuberculosis has been attributed to single nucleotide polymorphisms (SNPs) in the catalase peroxidase enzyme (katG), a protein important in the activation of the pro-drug isoniazid. The SNPs especially at position 315 of the katG enzyme are believed to reduce the sensitivity of the M. tuberculosis to isoniazid while still maintaining the enzyme’s catalytic activity - a mechanism not completely understood. KatG protein is important for protecting the bacteria from hydro peroxides and hydroxyl radicals present in an aerobic environment. This study focused on understanding the mechanism of isoniazid drug resistance in M. tuberculosis as a result of high confidence mutations in the katG through modelling the enzyme with its respective variants, performing MD simulations to explore the protein behaviour, calculating the dynamic residue network analysis (DRN) of the variants in respect to the wild type katG and finally performing alanine scanning. From the MD simulations, it was observed that the high confidence mutations i.e. S140R, S140N, G279D, G285D, S315T, S315I, S315R, S315N, G316D, S457I and G593D were not only reducing the backbone flexibility of the protein but also reducing the protein’s conformational variation and space. All the variant protein structures were observed to be more compact compared to the wild type. Residue fluctuation results indicated reduced residue flexibility across all variants in the loop region (position 26-110) responsible for katG dimerization. In addition, mutation S315T is believed to reduce the size of the active site access channel in the protein. From the DRN data, residues in the interface region between the N and C-terminal domains were observed to gain importance in the variants irrespective of the mutation location indicating an allosteric effect of the mutations on the interface region. Alanine scanning results established that residue Leucine at position 48 was not only important in the protein communication but also a destabilizing residue across all the variants. The study not only demonstrated change in the protein behaviour but also showed allosteric effect of the mutations in the katG protein.
- Full Text:
- Date Issued: 2020
Studies in the thiophenol mediated substitution and reductive dehalogenation of 3 bromoacetylcoumarins
- Authors: Magwenzi, Faith N
- Date: 2017
- Subjects: 3-bromoacetylcoumarins , Coumarins , Halogens -- Decontamination , Thiols , Plasmodium falciparum , Malaria -- Chemotherapy
- Language: English
- Type: Thesis , Masters , MPharm
- Identifier: http://hdl.handle.net/10962/45769 , vital:25546
- Description: A previous study conducted by our group identified indolyl-3-ethanone-a-thioethers (2.1a and 2.1b) as non-toxic, nanomolar, in vitro inhibitors of Plasmodium falciparum. Since the coumarin scaffold is associated with numerous biologically active compounds including antiprotozoal, anti-viral, anti-bacterial, and anti-inflammatory agents we were prompted to investigate coumaryl-3-ethanone-a-thioethers (2.1c) inspired by the activity of 2.1a and 2.1b against P. falciparum. We proposed a three-step synthesis of our target compounds 2.1c. The first step involved the Knoevenagel synthesis of 3-acetyl coumarins (2.3.1a - e) followed by a selective a-bromination to yield 3-bromoacetyl coumarin (2.2a). The final proposed step involved the nucleophilic displacement of the bromine by appropriately substituted thiophenols in either the presence or absence of base (K2CO3). Our initial findings revealed an unexpected major reductive dehalogenation of 2.2a into 2.3.1a. Further investigation revealed a close relationship between the electron withdrawing or donating nature of the thiophenol substituents and the relative formation of nucleophilic substitution or reductive dehalogenation products. Desired thioether products were obtained in higher yields when thiophenol was substituted with electron donating groups i.e. more nucleophilic thiophenols, while conversely, electron withdrawing substituents (i.e. lowered nucleophilicity) resulted in an increase of reductive dehalogenation. Furthermore, these results were consistent when experiments were conducted using either 2 or 1.2 equivalents of thiophenols which was an important observation in the context of two previous studies, by Oki et. al. and Israel et. al. Oki proposed that dehalogenation of a-chloro carbonyls occurs via sequential nucleophilic displacement of a-thioethers, while the study of Israel concluded that the dehalogenation of a-iodo carbonyls occurred in a single discreet step. Finally, in an effort to enhance nucleophilic substitution through the addition of K2CO3, we observed a Robinson annulation resulting in previously undescribed C-8 thiophenol functionalised dibenzo[b,d]pyran-6-ones (3.4a - e). In the introduction to this thesis, we briefly summarise the utility of coumarins in medicinal chemistry and related fields. Chapter two describes the rationalisation of our original research question and a retrosynthetic analysis of our desired compounds, followed by an initial description of the unexpected reductive dehalogenation. Chapter 3, begins with a brief review of reductive dehalogenation of a-halocarbonyls, and is followed by an analysis and discussion of our results in the context of the studies by Israel et. al. and Oki et. al.
- Full Text:
- Date Issued: 2017
- Authors: Magwenzi, Faith N
- Date: 2017
- Subjects: 3-bromoacetylcoumarins , Coumarins , Halogens -- Decontamination , Thiols , Plasmodium falciparum , Malaria -- Chemotherapy
- Language: English
- Type: Thesis , Masters , MPharm
- Identifier: http://hdl.handle.net/10962/45769 , vital:25546
- Description: A previous study conducted by our group identified indolyl-3-ethanone-a-thioethers (2.1a and 2.1b) as non-toxic, nanomolar, in vitro inhibitors of Plasmodium falciparum. Since the coumarin scaffold is associated with numerous biologically active compounds including antiprotozoal, anti-viral, anti-bacterial, and anti-inflammatory agents we were prompted to investigate coumaryl-3-ethanone-a-thioethers (2.1c) inspired by the activity of 2.1a and 2.1b against P. falciparum. We proposed a three-step synthesis of our target compounds 2.1c. The first step involved the Knoevenagel synthesis of 3-acetyl coumarins (2.3.1a - e) followed by a selective a-bromination to yield 3-bromoacetyl coumarin (2.2a). The final proposed step involved the nucleophilic displacement of the bromine by appropriately substituted thiophenols in either the presence or absence of base (K2CO3). Our initial findings revealed an unexpected major reductive dehalogenation of 2.2a into 2.3.1a. Further investigation revealed a close relationship between the electron withdrawing or donating nature of the thiophenol substituents and the relative formation of nucleophilic substitution or reductive dehalogenation products. Desired thioether products were obtained in higher yields when thiophenol was substituted with electron donating groups i.e. more nucleophilic thiophenols, while conversely, electron withdrawing substituents (i.e. lowered nucleophilicity) resulted in an increase of reductive dehalogenation. Furthermore, these results were consistent when experiments were conducted using either 2 or 1.2 equivalents of thiophenols which was an important observation in the context of two previous studies, by Oki et. al. and Israel et. al. Oki proposed that dehalogenation of a-chloro carbonyls occurs via sequential nucleophilic displacement of a-thioethers, while the study of Israel concluded that the dehalogenation of a-iodo carbonyls occurred in a single discreet step. Finally, in an effort to enhance nucleophilic substitution through the addition of K2CO3, we observed a Robinson annulation resulting in previously undescribed C-8 thiophenol functionalised dibenzo[b,d]pyran-6-ones (3.4a - e). In the introduction to this thesis, we briefly summarise the utility of coumarins in medicinal chemistry and related fields. Chapter two describes the rationalisation of our original research question and a retrosynthetic analysis of our desired compounds, followed by an initial description of the unexpected reductive dehalogenation. Chapter 3, begins with a brief review of reductive dehalogenation of a-halocarbonyls, and is followed by an analysis and discussion of our results in the context of the studies by Israel et. al. and Oki et. al.
- Full Text:
- Date Issued: 2017
The development of an instrument to measure intrapreneurship: entrepreneurship within the corporate setting
- Authors: Hill, Marguerite Elizabeth
- Date: 2003
- Subjects: Entrepreneurship , Psychology, Industrial , Organizational change
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2991 , http://hdl.handle.net/10962/d1002500 , Entrepreneurship , Psychology, Industrial , Organizational change
- Description: “Intrapreneurship is not a choice, it is the only survival attitude” (Pinchot, 2000, p.75). In 1985 Pinchot coined the term ‘intrapreneurship’, short for intra-corporate entrepreneurship, which describes the practice of entrepreneurship within organisations. Intrapreneurship is increasingly becoming a term used in the business world to describe organisations that are willing to pursue opportunities, initiate actions, and emphasise new, innovative products or services. Due to the dynamic nature of modern organisations, it is imperative that organisations and their managers remain receptive to new ideas, approaches and attitudes. It is therefore the belief that rapid and cost-effective innovation is the primary source of lasting competitive advantage in the twenty-first century, leaving organisations no alternative but to become intrapreneurial or cease to exist. This thesis focuses on this need and examines ways in which intrapreneurship can be measured in organisations in order to provide a benchmark for further organisational development. A questionnaire (known as the Intrapreneurial Intensity Index) was designed and distributed to a sample of 500 employees working in large South African organisations, which classified themselves as ‘forward-thinking’ and aimed for an intrapreneurial ‘type of thinking’. The results obtained from these questionnaires underwent item analysis, after which the questionnaire was redesigned in an electronic format. A pilot case study was then conducted in order to test the reliability of the instrument. Finally the questionnaire was redistributed to a sample of six organisations that are viewed as being ‘intrapreneurial’ and two that are regarded as being ‘non-intrapreneurial’. The data from this sample was used to test the validity of the Intrapreneurial Intensity Index and to demonstrate its application. This study resulted in an instrument that can be used to ascertain the intensity of intrapreneurship present in a large organisation. Specifically, this instrument can provide an overall view of the organisation’s intrapreneurial ability, as well as identify the specific areas in the organisation that require change or modification in order to become more intrapreneurial. This instrument provides a valuable means of identifying areas in need of organisational change, by determining an organisation’s intrapreneurial properties in the organisation’s core areas.
- Full Text:
- Date Issued: 2003
- Authors: Hill, Marguerite Elizabeth
- Date: 2003
- Subjects: Entrepreneurship , Psychology, Industrial , Organizational change
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2991 , http://hdl.handle.net/10962/d1002500 , Entrepreneurship , Psychology, Industrial , Organizational change
- Description: “Intrapreneurship is not a choice, it is the only survival attitude” (Pinchot, 2000, p.75). In 1985 Pinchot coined the term ‘intrapreneurship’, short for intra-corporate entrepreneurship, which describes the practice of entrepreneurship within organisations. Intrapreneurship is increasingly becoming a term used in the business world to describe organisations that are willing to pursue opportunities, initiate actions, and emphasise new, innovative products or services. Due to the dynamic nature of modern organisations, it is imperative that organisations and their managers remain receptive to new ideas, approaches and attitudes. It is therefore the belief that rapid and cost-effective innovation is the primary source of lasting competitive advantage in the twenty-first century, leaving organisations no alternative but to become intrapreneurial or cease to exist. This thesis focuses on this need and examines ways in which intrapreneurship can be measured in organisations in order to provide a benchmark for further organisational development. A questionnaire (known as the Intrapreneurial Intensity Index) was designed and distributed to a sample of 500 employees working in large South African organisations, which classified themselves as ‘forward-thinking’ and aimed for an intrapreneurial ‘type of thinking’. The results obtained from these questionnaires underwent item analysis, after which the questionnaire was redesigned in an electronic format. A pilot case study was then conducted in order to test the reliability of the instrument. Finally the questionnaire was redistributed to a sample of six organisations that are viewed as being ‘intrapreneurial’ and two that are regarded as being ‘non-intrapreneurial’. The data from this sample was used to test the validity of the Intrapreneurial Intensity Index and to demonstrate its application. This study resulted in an instrument that can be used to ascertain the intensity of intrapreneurship present in a large organisation. Specifically, this instrument can provide an overall view of the organisation’s intrapreneurial ability, as well as identify the specific areas in the organisation that require change or modification in order to become more intrapreneurial. This instrument provides a valuable means of identifying areas in need of organisational change, by determining an organisation’s intrapreneurial properties in the organisation’s core areas.
- Full Text:
- Date Issued: 2003
A contribution to the petrology of kimberlites
- Authors: Kruger, Floris Johan
- Date: 1978 , 2013-10-17
- Subjects: Kimberlite -- Africa, Southern , Petrology , Igneous rocks -- Inclusions
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5024 , http://hdl.handle.net/10962/d1006886 , Kimberlite -- Africa, Southern , Petrology , Igneous rocks -- Inclusions
- Description: The petrogenetic relationships of the different varieties of kimberlite in the De Beers Mine and Letseng-Ia-terai composite diatremes have been investigated using petrographic and chemical methods. Kimberlites in the Letseng-Ia-terai diatreme were found to be strongly contaminated by crustal material, mainly basalt. A method to correct for the effects of the contamination has been developed and applied to these kimberlites. Using the corrected data, the four kimberlite types in each group appear to be related to each other by crystal/liquid fractionation models. However the two groups cannot be related to each other. The De Beer Mine has two varieties of kimberlite, a monticellite apatite and calcite rich variety which intruded first, and a phlogopite rich type forming a discrete cylindrical body within the earlier kimberlite. These two kimberlites do not appear to be related by any of the fractionation models discussed. An examination of the data from this work and published sources, suggests that kimberlites are derived from below the low velocity zone by small degrees of partial melting involving garnet lherzolite with subordinate phlogopite and carbonate. Diamonds are probably incorporated as xenocrysts in the magma. Upward movement and emplacement of kimberlite appears to have been very rapid. The diatremes were probably eroded and shaped by gas, derived from the kimberlite magma, escaping to surface along weak zones in the earth's crust. Xenoliths of crustal material incorporated in the kimberlite on intrusion have also been studied and various features due to alteration by the magma are described, including the formation of natrolite and cebollite. The latter is a rare mineral that has not been described from kimberlite before. , KMBT_363 , Adobe Acrobat 9.54 Paper Capture Plug-in
- Full Text:
- Date Issued: 1978
- Authors: Kruger, Floris Johan
- Date: 1978 , 2013-10-17
- Subjects: Kimberlite -- Africa, Southern , Petrology , Igneous rocks -- Inclusions
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5024 , http://hdl.handle.net/10962/d1006886 , Kimberlite -- Africa, Southern , Petrology , Igneous rocks -- Inclusions
- Description: The petrogenetic relationships of the different varieties of kimberlite in the De Beers Mine and Letseng-Ia-terai composite diatremes have been investigated using petrographic and chemical methods. Kimberlites in the Letseng-Ia-terai diatreme were found to be strongly contaminated by crustal material, mainly basalt. A method to correct for the effects of the contamination has been developed and applied to these kimberlites. Using the corrected data, the four kimberlite types in each group appear to be related to each other by crystal/liquid fractionation models. However the two groups cannot be related to each other. The De Beer Mine has two varieties of kimberlite, a monticellite apatite and calcite rich variety which intruded first, and a phlogopite rich type forming a discrete cylindrical body within the earlier kimberlite. These two kimberlites do not appear to be related by any of the fractionation models discussed. An examination of the data from this work and published sources, suggests that kimberlites are derived from below the low velocity zone by small degrees of partial melting involving garnet lherzolite with subordinate phlogopite and carbonate. Diamonds are probably incorporated as xenocrysts in the magma. Upward movement and emplacement of kimberlite appears to have been very rapid. The diatremes were probably eroded and shaped by gas, derived from the kimberlite magma, escaping to surface along weak zones in the earth's crust. Xenoliths of crustal material incorporated in the kimberlite on intrusion have also been studied and various features due to alteration by the magma are described, including the formation of natrolite and cebollite. The latter is a rare mineral that has not been described from kimberlite before. , KMBT_363 , Adobe Acrobat 9.54 Paper Capture Plug-in
- Full Text:
- Date Issued: 1978