Ecological engineering on rocky shores: grazing, predation, nutrient availability and their influence on epifaunal communities
- Authors: Ndhlovu, Aldwin
- Date: 2016
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/3453 , vital:20500
- Description: “Ecosystem engineers modify, create/destroy habitat and directly/indirectly modulate availability of resources to other species by causing physical state changes to biotic and abiotic materials” (Jones et al, 1994, page 1). Previous studies have analysed top-down and bottom-up relationships to determine which form of regulation is key in controlling community composition. This study assessed the direct and indirect effects of top down and bottom up factors on the epifaunal communities of macro-algae. Epifauna are subject to the direct top-down effects of predation and bottom up effects of habitat availability. Habitat availability in turn experiences the direct top down effects of grazing and bottom up effects of nutrient availability due to upwelling. Grazing and upwelling may therefore have indirect effects on macro-algal epifauna. Four treatments (Procedural controls, Controls, Predator or Grazer exclusion) set out in a block design (n = 5) were monitored monthly for algal cover of the substratum for 12 months with the surface area of algal plants and epifaunal species composition and abundances assessed at the end of the experiment. The red alga Gelidium pristoides was selected as the ecosystem engineer as it is common, supports a diverse community of epiphytic animals and acts as a nursery for small epifaunal organisms. The experiment was run at two upwelling sites interspersed with two non-upwelling sites. Sites were separated on scales of 100km along approximately 500km of coastline. Dipping whole algae in dish washing liquid provided a strong relationship between their surface area and the weight of the film of dish washing liquid covering them. Surface area was strongly correlated to dry weight but neither surface area nor dry weight was correlated to algal cover of the substratum. Algal cover was influenced by the interactions of treatment with site (nested in upwelling) and upwelling. At all sites, treatments that allowed access to grazers, Grazer + and Control treatments, showed no significant differences and these two treatments had lower algal cover than Predator + and Closed treatments which did not differ from one another 3 [Grazer + = Control < Predator + = Closed]. A total of 44 epifaunal species were identified, with the predominant orders being Amphipoda and Isopoda. Primer results showed that only site had a significant effect on species composition, with sites that were further apart being more different. Site (nested in upwelling) had an effect on total epifaunal abundances when data were non-normalised. When total epifaunal abundances were normalised for algal cover of the substratum or algal surface area to provide density data, predation had no significant effect. Grazing did have a significant effect, but only when data were normalised to algal surface area, not cover, leading to the conclusion that indirect top-down factors through grazing of the sea weed are important in structuring epifaunal communities depending on how habitat availability is measured.
- Full Text:
- Authors: Ndhlovu, Aldwin
- Date: 2016
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/3453 , vital:20500
- Description: “Ecosystem engineers modify, create/destroy habitat and directly/indirectly modulate availability of resources to other species by causing physical state changes to biotic and abiotic materials” (Jones et al, 1994, page 1). Previous studies have analysed top-down and bottom-up relationships to determine which form of regulation is key in controlling community composition. This study assessed the direct and indirect effects of top down and bottom up factors on the epifaunal communities of macro-algae. Epifauna are subject to the direct top-down effects of predation and bottom up effects of habitat availability. Habitat availability in turn experiences the direct top down effects of grazing and bottom up effects of nutrient availability due to upwelling. Grazing and upwelling may therefore have indirect effects on macro-algal epifauna. Four treatments (Procedural controls, Controls, Predator or Grazer exclusion) set out in a block design (n = 5) were monitored monthly for algal cover of the substratum for 12 months with the surface area of algal plants and epifaunal species composition and abundances assessed at the end of the experiment. The red alga Gelidium pristoides was selected as the ecosystem engineer as it is common, supports a diverse community of epiphytic animals and acts as a nursery for small epifaunal organisms. The experiment was run at two upwelling sites interspersed with two non-upwelling sites. Sites were separated on scales of 100km along approximately 500km of coastline. Dipping whole algae in dish washing liquid provided a strong relationship between their surface area and the weight of the film of dish washing liquid covering them. Surface area was strongly correlated to dry weight but neither surface area nor dry weight was correlated to algal cover of the substratum. Algal cover was influenced by the interactions of treatment with site (nested in upwelling) and upwelling. At all sites, treatments that allowed access to grazers, Grazer + and Control treatments, showed no significant differences and these two treatments had lower algal cover than Predator + and Closed treatments which did not differ from one another 3 [Grazer + = Control < Predator + = Closed]. A total of 44 epifaunal species were identified, with the predominant orders being Amphipoda and Isopoda. Primer results showed that only site had a significant effect on species composition, with sites that were further apart being more different. Site (nested in upwelling) had an effect on total epifaunal abundances when data were non-normalised. When total epifaunal abundances were normalised for algal cover of the substratum or algal surface area to provide density data, predation had no significant effect. Grazing did have a significant effect, but only when data were normalised to algal surface area, not cover, leading to the conclusion that indirect top-down factors through grazing of the sea weed are important in structuring epifaunal communities depending on how habitat availability is measured.
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Effect of lipid inclusion levels in aquafeed on carcass composition, quality change during storage and nutrient excretion in dusky kob (Argyrosomus japonicus)
- Authors: Ginindza, Nhlanhla Joseph
- Date: 2016
- Subjects: Aquaculture
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5387 , http://hdl.handle.net/10962/d1020854
- Description: Dusky kob, Argyrosomus japonicus, is an aquaculture species in South Africa that is in pilot commercial production. While the major nutrient requirements of the species are known, the advantages of incorporating formulated feeds into the diet of the species has yet to be fully explored. Research on formulated feed composition is required to: minimise input costs; improve the organoleptic properties and meat quality; and minimise nutrient loss, which contributes to environmental pollution. This study sought to test the impact of different lipid levels in aquafeeds fed to dusky kob juveniles by determining: (i) growth performance, feeding efficiency, proximate and fatty acid composition; (ii) chemical changes and shelf-life of refrigerated fish fillets; and (iii) metabolic rates and nitrogen excretion of juvenile dusky kob. And more...
- Full Text:
- Authors: Ginindza, Nhlanhla Joseph
- Date: 2016
- Subjects: Aquaculture
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5387 , http://hdl.handle.net/10962/d1020854
- Description: Dusky kob, Argyrosomus japonicus, is an aquaculture species in South Africa that is in pilot commercial production. While the major nutrient requirements of the species are known, the advantages of incorporating formulated feeds into the diet of the species has yet to be fully explored. Research on formulated feed composition is required to: minimise input costs; improve the organoleptic properties and meat quality; and minimise nutrient loss, which contributes to environmental pollution. This study sought to test the impact of different lipid levels in aquafeeds fed to dusky kob juveniles by determining: (i) growth performance, feeding efficiency, proximate and fatty acid composition; (ii) chemical changes and shelf-life of refrigerated fish fillets; and (iii) metabolic rates and nitrogen excretion of juvenile dusky kob. And more...
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Effects of the biocontrol agent, coelocephalapion camarae kissinger, galling on petiole tissues, plant growth and stored reserves in plant parts of two lantana camara L.(verbenaceae) varieties
- Authors: Kistensamy, Yoganambal
- Date: 2016
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/3126 , vital:20372
- Description: The agent evaluated in this study, Coelocephalapion camarae Kissinger (Brentidae), a petiole galling apionid, was released against Lantana camara L. (Verbenaceae) in South Africa and has the potential to significantly contribute to the control of this noxious weed. An important aspect of evaluating the effectiveness of a biocontrol agent; include the understanding of the mechanism in which the biocontrol agent causes damage to the plant and the plant’s response to this damage. Another aspect that was considered in evaluating the effects of the apionid was the varietal differences that exist within the weedy L. camara complex. Larval feeding of C. camarae damaged the tissue in the petioles causing gall formation and this was quantified on two common South African L. camara varieties (017 and 018). Up to 100% of the vascular tissue (xylem and phloem) of effected petioles was eaten by larvae, 25 days after ovipostion in both the L. camara varieties, effectively severing the vascular connection from the leaves. The effect of feeding and galling by different population densities of C. camarae, on biomass and total soluble sugar and starch concentrations of different plant parts was measured on these two varieties during autumn, and compared to a similar study, done during summer. Relatively low galling percentages were achieved in the experiments of this study. Plant growth was less affected by apionid feeding at similar galling levels, as higher galling densities in these trials were similar to those at low exposures in trials by Baars (2002). The dry weights of all individual and combined plant parts for lantana variety 017 was less for both adult density exposures after 70 days compared to the weights of its controls, although not statistically significant at P>0.05 The opposite effect, though barely noticeable was recorded for lantana variety 018; here, the dry weights of individual plant parts and as whole plants weighed more in the plants exposed to both densities of weevil feeding and galling after 70 days, compared to its controls. Coelocephalapion camarae herbivory may thus be more effective in inflicting damage on some L. camara varieties compared to others. The effects of late season carbohydrate storage revealed that, from early- to mid-autumn starch concentrations increased significantly in stems of both L. camara varieties and L. camara var. 018 had larger starch reserves for winter. In L. camara var. 018 stems, starch increased 52 times and concentrations doubled in stems of L. camara var 017. The increase in the sugar and decrease in starch concentrations in leaves of plants of both varieties exposed to apionids in this study was attributed to a possible reduction of available nitrogen and phosphorus, due to apionid feeding, whilst starch was reallocated within the plants to stems and roots. The increase in starch concentrations in stems of plants that were exposed to apionids may have been expected, as compensation for herbivory has been associated with, increases in photosynthetic rates and the mobilization of stored resources. Herbivory by the apionid early in the growing season may be easily compensated for by L. camara as there are nutrient flushes experienced by plants that allows the maximum uptake of nutrients facilitating recovery, whereas later in the season plants suffer lower nutrient availability and don’t recover so readily. Both early and late in the season the accumulated effects of C. camarae feeding over time will undoubtedly decrease fitness of most lantana varieties.
- Full Text:
- Authors: Kistensamy, Yoganambal
- Date: 2016
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/3126 , vital:20372
- Description: The agent evaluated in this study, Coelocephalapion camarae Kissinger (Brentidae), a petiole galling apionid, was released against Lantana camara L. (Verbenaceae) in South Africa and has the potential to significantly contribute to the control of this noxious weed. An important aspect of evaluating the effectiveness of a biocontrol agent; include the understanding of the mechanism in which the biocontrol agent causes damage to the plant and the plant’s response to this damage. Another aspect that was considered in evaluating the effects of the apionid was the varietal differences that exist within the weedy L. camara complex. Larval feeding of C. camarae damaged the tissue in the petioles causing gall formation and this was quantified on two common South African L. camara varieties (017 and 018). Up to 100% of the vascular tissue (xylem and phloem) of effected petioles was eaten by larvae, 25 days after ovipostion in both the L. camara varieties, effectively severing the vascular connection from the leaves. The effect of feeding and galling by different population densities of C. camarae, on biomass and total soluble sugar and starch concentrations of different plant parts was measured on these two varieties during autumn, and compared to a similar study, done during summer. Relatively low galling percentages were achieved in the experiments of this study. Plant growth was less affected by apionid feeding at similar galling levels, as higher galling densities in these trials were similar to those at low exposures in trials by Baars (2002). The dry weights of all individual and combined plant parts for lantana variety 017 was less for both adult density exposures after 70 days compared to the weights of its controls, although not statistically significant at P>0.05 The opposite effect, though barely noticeable was recorded for lantana variety 018; here, the dry weights of individual plant parts and as whole plants weighed more in the plants exposed to both densities of weevil feeding and galling after 70 days, compared to its controls. Coelocephalapion camarae herbivory may thus be more effective in inflicting damage on some L. camara varieties compared to others. The effects of late season carbohydrate storage revealed that, from early- to mid-autumn starch concentrations increased significantly in stems of both L. camara varieties and L. camara var. 018 had larger starch reserves for winter. In L. camara var. 018 stems, starch increased 52 times and concentrations doubled in stems of L. camara var 017. The increase in the sugar and decrease in starch concentrations in leaves of plants of both varieties exposed to apionids in this study was attributed to a possible reduction of available nitrogen and phosphorus, due to apionid feeding, whilst starch was reallocated within the plants to stems and roots. The increase in starch concentrations in stems of plants that were exposed to apionids may have been expected, as compensation for herbivory has been associated with, increases in photosynthetic rates and the mobilization of stored resources. Herbivory by the apionid early in the growing season may be easily compensated for by L. camara as there are nutrient flushes experienced by plants that allows the maximum uptake of nutrients facilitating recovery, whereas later in the season plants suffer lower nutrient availability and don’t recover so readily. Both early and late in the season the accumulated effects of C. camarae feeding over time will undoubtedly decrease fitness of most lantana varieties.
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Electrode surface modification using iron(II) phthalocyanine immobilized via electrografting and click chemistry and clicked onto azide-functionalized quantum dots: applications in electrocatalysis
- Authors: Nxele, Siphesihle Robin
- Date: 2016
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/3464 , vital:20501
- Description: Tetrakis(5-hexynoxy)Fe(II) phthalocyanine was used alone and in combination with quantum dots (QDs) in order to test the electrocatalytic ability with hydrazine and paraquat as the analytes of interest. This novel phthalocaynine was successfully synthesised and characterized using various characterisation techniques. The QDs used were the well-known core-shell CdSe/ZnS nanostructures. The fabrication of glassy carbon electrodes involved covalent attachment by electrochemical grafting and click chemistry for the first part of the work and the second part involved the conjugation of the synthesised QDs and the phthalocyanine by click chemistry. This approach of conjugating these nanostructures introduced another aspect of novelty to the work reported in this thesis. The immobilisation of this conjugate on a glassy carbon electrode (GCE) was achieved by adsorption. Characterisation techniques such as infrared spectroscopy, x-ray diffractometry, UV/vis spectroscopy, transmission electron microscopy and x-ray photoelectron spectroscopy were used to characterise the molecules and conjugates of interest. With respect to the electrocatalytic part of the work, electrode surface characterisation involved scanning electrochemical microscopy and cyclic voltammetry to determine changes in the nature of the surface as well as reactivity of the surface at different modification steps. Detection limits and the sensitivity determined for the electrocatalysts fabricated here proved to be an improvement compared to other reported work involving phthalocyanines and the test analytes chosen for application. With respect to the conjugate, the electrocatalytic ability was improved when the QDs and phthalocyanine were combined using click chemistry compared to using the phthalocyanine alone.
- Full Text:
- Authors: Nxele, Siphesihle Robin
- Date: 2016
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/3464 , vital:20501
- Description: Tetrakis(5-hexynoxy)Fe(II) phthalocyanine was used alone and in combination with quantum dots (QDs) in order to test the electrocatalytic ability with hydrazine and paraquat as the analytes of interest. This novel phthalocaynine was successfully synthesised and characterized using various characterisation techniques. The QDs used were the well-known core-shell CdSe/ZnS nanostructures. The fabrication of glassy carbon electrodes involved covalent attachment by electrochemical grafting and click chemistry for the first part of the work and the second part involved the conjugation of the synthesised QDs and the phthalocyanine by click chemistry. This approach of conjugating these nanostructures introduced another aspect of novelty to the work reported in this thesis. The immobilisation of this conjugate on a glassy carbon electrode (GCE) was achieved by adsorption. Characterisation techniques such as infrared spectroscopy, x-ray diffractometry, UV/vis spectroscopy, transmission electron microscopy and x-ray photoelectron spectroscopy were used to characterise the molecules and conjugates of interest. With respect to the electrocatalytic part of the work, electrode surface characterisation involved scanning electrochemical microscopy and cyclic voltammetry to determine changes in the nature of the surface as well as reactivity of the surface at different modification steps. Detection limits and the sensitivity determined for the electrocatalysts fabricated here proved to be an improvement compared to other reported work involving phthalocyanines and the test analytes chosen for application. With respect to the conjugate, the electrocatalytic ability was improved when the QDs and phthalocyanine were combined using click chemistry compared to using the phthalocyanine alone.
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Exorcising the Past: History, Hauntings and Evil in Neo-Gothic Fiction
- Authors: Van der Wielen, Karlien
- Date: 2016
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2333 , http://hdl.handle.net/10962/d1021257
- Description: This thesis explores the conventions of both historical and Gothic fiction in order to investigate what seems to be a recurrent impulse to exorcise the past in what I define as contemporary Neo-Gothic fiction. It therefore attempts to establish a distinction between Neo-Gothic fiction and other forms of contemporary Gothic fiction by focusing on the treatment of history, the supernatural and the grand narrative of progress in three contemporary Gothic novels: The Little Stranger by Sarah Waters, The Historian by Elizabeth Kostova and The Accursed by Joyce Carol Oates. This thesis argues that the most potent manifestation of history can be found in the representation of the revenant in Neo-Gothic fiction, which exhibits a disruptive and evil ontology that problematises the exorcism of the past. Furthermore, the reactions of ‘modern’ characters to these revenants illustrate the imperative to exorcise the past, and therefore the treatment of history and the past is reflected in the interaction between the ‘modern’ characters and the Gothic revenants. Through this interaction as well as the parody of traditional Gothic and historical fiction conventions, Neo-Gothic fiction constructs a critique of the Enlightenment’s grand narrative of progress. Paradoxically, this constitutes Neo-Gothic fiction’s own attempt to exorcise the past, which it recognises in a simplified and reductive narrative of history propounded through the grand narrative of progress. This thesis therefore pays particular attention to the configuration of revenants as evil and ‘modern’ humans as good, and the disruption of this simple binary that is effected through Neo-Gothic fiction’s subversion of the grand narrative of progress. This focus allows for the theorisation of the revenant through Jacques Derrida’s notion of ‘hauntology’ and Julia Kristeva’s ‘the abject’, the investigation of the treatment of history in Neo-Gothic fiction and the exploration of very recent Gothic texts that have not yet received much critical attention.
- Full Text:
- Authors: Van der Wielen, Karlien
- Date: 2016
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2333 , http://hdl.handle.net/10962/d1021257
- Description: This thesis explores the conventions of both historical and Gothic fiction in order to investigate what seems to be a recurrent impulse to exorcise the past in what I define as contemporary Neo-Gothic fiction. It therefore attempts to establish a distinction between Neo-Gothic fiction and other forms of contemporary Gothic fiction by focusing on the treatment of history, the supernatural and the grand narrative of progress in three contemporary Gothic novels: The Little Stranger by Sarah Waters, The Historian by Elizabeth Kostova and The Accursed by Joyce Carol Oates. This thesis argues that the most potent manifestation of history can be found in the representation of the revenant in Neo-Gothic fiction, which exhibits a disruptive and evil ontology that problematises the exorcism of the past. Furthermore, the reactions of ‘modern’ characters to these revenants illustrate the imperative to exorcise the past, and therefore the treatment of history and the past is reflected in the interaction between the ‘modern’ characters and the Gothic revenants. Through this interaction as well as the parody of traditional Gothic and historical fiction conventions, Neo-Gothic fiction constructs a critique of the Enlightenment’s grand narrative of progress. Paradoxically, this constitutes Neo-Gothic fiction’s own attempt to exorcise the past, which it recognises in a simplified and reductive narrative of history propounded through the grand narrative of progress. This thesis therefore pays particular attention to the configuration of revenants as evil and ‘modern’ humans as good, and the disruption of this simple binary that is effected through Neo-Gothic fiction’s subversion of the grand narrative of progress. This focus allows for the theorisation of the revenant through Jacques Derrida’s notion of ‘hauntology’ and Julia Kristeva’s ‘the abject’, the investigation of the treatment of history in Neo-Gothic fiction and the exploration of very recent Gothic texts that have not yet received much critical attention.
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Exploration, monetization, disillusion: a history of upstream oil development in the onshore Algoa basin
- Authors: James, Jonathan Scott
- Date: 2016
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/3870 , vital:20551
- Description: The onshore Algoa basin has, since the mid-1960s, been an area of interest for oil and gas exploration. Despite the general lack of knowledge and publicly available information on the topic, a large amount of geological and geophysical data has been collected on the region owing to the oil and gas exploration. The intended aim of this thesis is to compile and construct a historical narrative of the oil and gas exploration that took place within the onshore Algoa basin, and to then contextualize that localized narrative within the greater macro-narrative of the global oil and gas industry. This thesis is primarily concerned with the time period beginning in the early 1960s up to mid-2014, however reference is also made to events pre-1960. For the purposes of compartmentalizing the various areas of research covered, the thesis has been divided into three broad areas of interest: the geology of the onshore Algoa basin, the global oil market and its impact on exploration therein, and the attempts to monetize the leases that came to be purchased post-exploration. The narrative on the geology of the onshore Algoa basin is aimed at providing a summarized account of the most important details pertaining to the search for petroleum systems in simplified, yet accurate, language. The aspects of the geology which command the most attention are those which are necessary in functioning petroleum systems such as suitable permeabilities, porosities, reservoir rocks, trapping mechanisms and cap rocks. The global oil and gas market is also used to contextualize the search for oil and gas within the onshore Algoa basin and is explained against the backdrop of the global oil trade and the sanctions imposed on the apartheid state. Furthermore, the analysis of the attempts to monetize leases within the onshore Algoa basin will provide a financial reference point to the shortcomings of the exploration and monetization efforts. The purpose of this thesis is to construct a historical narrative of the onshore Algoa basin which not only gives an accurate portrayal of the exploration efforts that have taken place thus far, but to also provide a enough detail of those exploration efforts to indicate the future of the onshore Algoa basin as an exploration play.
- Full Text:
- Authors: James, Jonathan Scott
- Date: 2016
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/3870 , vital:20551
- Description: The onshore Algoa basin has, since the mid-1960s, been an area of interest for oil and gas exploration. Despite the general lack of knowledge and publicly available information on the topic, a large amount of geological and geophysical data has been collected on the region owing to the oil and gas exploration. The intended aim of this thesis is to compile and construct a historical narrative of the oil and gas exploration that took place within the onshore Algoa basin, and to then contextualize that localized narrative within the greater macro-narrative of the global oil and gas industry. This thesis is primarily concerned with the time period beginning in the early 1960s up to mid-2014, however reference is also made to events pre-1960. For the purposes of compartmentalizing the various areas of research covered, the thesis has been divided into three broad areas of interest: the geology of the onshore Algoa basin, the global oil market and its impact on exploration therein, and the attempts to monetize the leases that came to be purchased post-exploration. The narrative on the geology of the onshore Algoa basin is aimed at providing a summarized account of the most important details pertaining to the search for petroleum systems in simplified, yet accurate, language. The aspects of the geology which command the most attention are those which are necessary in functioning petroleum systems such as suitable permeabilities, porosities, reservoir rocks, trapping mechanisms and cap rocks. The global oil and gas market is also used to contextualize the search for oil and gas within the onshore Algoa basin and is explained against the backdrop of the global oil trade and the sanctions imposed on the apartheid state. Furthermore, the analysis of the attempts to monetize leases within the onshore Algoa basin will provide a financial reference point to the shortcomings of the exploration and monetization efforts. The purpose of this thesis is to construct a historical narrative of the onshore Algoa basin which not only gives an accurate portrayal of the exploration efforts that have taken place thus far, but to also provide a enough detail of those exploration efforts to indicate the future of the onshore Algoa basin as an exploration play.
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Exploring how grade 12 Physical Sciences learners make sense of the concepts of work and energy
- Authors: Mapfumo, Alfred Khumbulani
- Date: 2016
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: http://hdl.handle.net/10962/1363 , vital:20050
- Description: Physical Sciences is one of the subjects in which students perform most poorly in the National Senior Certificate examinations. For example, in the Eastern Cape in 2013, a mere 29.9% of the candidates who sat for the Physical Sciences National Senior Certificate examination managed to achieve a mark of 40% or above (Department of Basic Education, 2014). According to the Chief Markers’ reports (ibid), questions on the topic of Work, Energy and Power are amongst the most poorly answered in the National Senior Certificate examinations. This fact triggered my interest to explore how grade 12 Physical Sciences learners make sense of the concepts of Work and Energy with particular emphasis on the work-energy theorem and its application in problem solving. I carried out the study in a village school in the Queenstown district. The study adopted an interpretive paradigm in which the case study approach was used. Data were generated using a diagnostic test, focus group interviews, video-recorded lessons, analysis of learner journals and a summative test. Analysis of the qualitative data involved identifying themes from the data and using analytical statements that answered the research questions. The study was informed by Vygotsky’s (1978) social constructivism theory, and in particular, the notions of the mediation of learning and the Zone of Proximal Development (ZPD). Learners were given tasks on the work-energy theorem and related concepts and these were designed in such a way that they were situated in the learners’ ZPD, since this is where most powerful learning takes place (Thompson, 2013). The findings of the study revealed that grade 12 Physical Sciences learners do not have sufficient prior knowledge on concepts related to the work-energy theory to successfully make sense of the work-energy theorem. The other finding is that learners construct knowledge of the work-energy theorem and its application collaboratively through group work. In the group discussions learners used isiXhosa and this enhanced their sense making. A number of challenges that make it difficult for learners to solve problems using the work-energy theorem were identified.
- Full Text:
- Authors: Mapfumo, Alfred Khumbulani
- Date: 2016
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: http://hdl.handle.net/10962/1363 , vital:20050
- Description: Physical Sciences is one of the subjects in which students perform most poorly in the National Senior Certificate examinations. For example, in the Eastern Cape in 2013, a mere 29.9% of the candidates who sat for the Physical Sciences National Senior Certificate examination managed to achieve a mark of 40% or above (Department of Basic Education, 2014). According to the Chief Markers’ reports (ibid), questions on the topic of Work, Energy and Power are amongst the most poorly answered in the National Senior Certificate examinations. This fact triggered my interest to explore how grade 12 Physical Sciences learners make sense of the concepts of Work and Energy with particular emphasis on the work-energy theorem and its application in problem solving. I carried out the study in a village school in the Queenstown district. The study adopted an interpretive paradigm in which the case study approach was used. Data were generated using a diagnostic test, focus group interviews, video-recorded lessons, analysis of learner journals and a summative test. Analysis of the qualitative data involved identifying themes from the data and using analytical statements that answered the research questions. The study was informed by Vygotsky’s (1978) social constructivism theory, and in particular, the notions of the mediation of learning and the Zone of Proximal Development (ZPD). Learners were given tasks on the work-energy theorem and related concepts and these were designed in such a way that they were situated in the learners’ ZPD, since this is where most powerful learning takes place (Thompson, 2013). The findings of the study revealed that grade 12 Physical Sciences learners do not have sufficient prior knowledge on concepts related to the work-energy theory to successfully make sense of the work-energy theorem. The other finding is that learners construct knowledge of the work-energy theorem and its application collaboratively through group work. In the group discussions learners used isiXhosa and this enhanced their sense making. A number of challenges that make it difficult for learners to solve problems using the work-energy theorem were identified.
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Exploring perceptions on aesthetics and emotional labour experienced by women working in two different clothing retail shops in Port Elizabeth and Grahamstown
- Authors: Dalikeni, Tawonga
- Date: 2016
- Language: English
- Type: Thesis , Masters , MSocSc
- Identifier: http://hdl.handle.net/10962/3750 , vital:20541
- Description: The retail industry is the fastest growing sector in the economy contributing trillions towards the global revenue. In a post-apartheid South African economy that is experiencing increased buying power, the clothing retail sector to be specific is consequently flourishing. However, the economy is faced by structural adjustments; an accompanying concern is how foreign direct investments and pressures of globalization impact the operation of clothing retail shops. The main focus of this thesis based on the qualitative research methodology is emotional and aesthetic labour being experienced by women working in two clothing retail shops in Port Elizabeth and Grahamstown. Empirical data shows that emotional labour is a dominant form of labour in the clothing retail shops under investigation. The women working as sales assistants are trained to exude a certain emotional aura when dealing with customers to build a relationship that will encourage the customer to purchase from the shop. Aesthetic labour on the other hand is an important public relations strategy used as sales assistants dress in a way that represents their company brand. Edgars employees dress elegantly because they focus more on formal dressing whilst Mr Price employees dress more casually because they focus on casual and relaxed fashion. Besides these external attributes, the study showed that certain aspects of the job are fairly similar. With codes of happiness and strings of dissatisfaction towards their job requirements, the women’s social lives suffer the atrocities of their long working hours and limited off-duty days.
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- Authors: Dalikeni, Tawonga
- Date: 2016
- Language: English
- Type: Thesis , Masters , MSocSc
- Identifier: http://hdl.handle.net/10962/3750 , vital:20541
- Description: The retail industry is the fastest growing sector in the economy contributing trillions towards the global revenue. In a post-apartheid South African economy that is experiencing increased buying power, the clothing retail sector to be specific is consequently flourishing. However, the economy is faced by structural adjustments; an accompanying concern is how foreign direct investments and pressures of globalization impact the operation of clothing retail shops. The main focus of this thesis based on the qualitative research methodology is emotional and aesthetic labour being experienced by women working in two clothing retail shops in Port Elizabeth and Grahamstown. Empirical data shows that emotional labour is a dominant form of labour in the clothing retail shops under investigation. The women working as sales assistants are trained to exude a certain emotional aura when dealing with customers to build a relationship that will encourage the customer to purchase from the shop. Aesthetic labour on the other hand is an important public relations strategy used as sales assistants dress in a way that represents their company brand. Edgars employees dress elegantly because they focus more on formal dressing whilst Mr Price employees dress more casually because they focus on casual and relaxed fashion. Besides these external attributes, the study showed that certain aspects of the job are fairly similar. With codes of happiness and strings of dissatisfaction towards their job requirements, the women’s social lives suffer the atrocities of their long working hours and limited off-duty days.
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Exploring teacher leadership: A case study at a senior secondary school in the Ohangwena region, Namibia
- Authors: Hamatwi, Isak
- Date: 2016
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: http://hdl.handle.net/10962/1275 , vital:20042
- Description: Leadership has been for long thought to centre on the actions of a positional head of the organisation crafting the vision and influencing followers’ behaviour based on his/her charisma and legal authority in a quest to achieve the set goals (Christie, 2010). However, contemporary views “emphasise leadership as relational” (Van der Mescht & Tyala, 2008, p. 226) and focuses more on the practice while taking form “in the interactions between leaders and followers” (Spillane, 2005, p. 146). Looking through the lens of distributed leadership and using the Grant’s (2008; 2012) model of teacher leadership as a data analytical tool, this research study aimed to explore the enactment of teacher leadership at a secondary school in the Ohangwena region, Namibia. The motivation of this research study was twofold; one, it was due to my personal interest in getting a deeper understanding of what constituted teacher leadership as a concept which is gaining momentum in the educational leadership discipline; two, it was due to the evident knowledge gap existing on the concept of teacher leadership as there seemed to be very less research done on the concept. Using observation schedules, survey questionnaires, semi-structured interview schedules and analysing documents as data collecting tools, the study was geared towards answering four research questions which were driving the study, namely; i) In what ways do teachers participate in the leadership activities of the school? ii) What is the nature of the relations of these leadership activities? iii) What factors that may constrain the leadership activities of these teachers? iv) How do the principal and the School Management Team (SMT) encourage teacher leadership at the school? The study was of a qualitative nature located in the interpretive paradigm. A purposive sampling method was used to select research participants The findings of the study indicated that the research participants had a general understanding of what teacher leadership entails. Teachers enacted leadership across the four zones of Grant’s (2008; 2012) model of teacher leadership, though with very limited teacher leadership enactment in zone four. Zones one, two and three proved to be the popular media of teacher leadership enactment wherein teachers led in their classrooms enforcing discipline, serving as guides and caregivers to their learners (zone one). Teachers then extended their leadership outside their classrooms where they served as decision makers, curriculum developers for knowledge enhancement through reflective teaching and sport coaches (zone two). In Zone three, teachers led in committees’ structures, as mentors of learners, policy makers and as models of good practice. Zone four was the least media of teacher leadership. The data pointed to a host of factors that prevented teachers to assume leadership at the case study school, namely; ignorance and fear for accountability, policy and regulatory limitations, time limitations, limited skills and teachers as barriers to teacher leadership in terms of apathy, lack of confidence, negative attitude and anti-social behaviours as well as professional jealous. Nevertheless, the principal and the SMT emerged as catalysts for teacher leadership at the school as they enabled teacher leadership in a number of ways, namely, through delegation, motivation, free choice, open engagement, moral support and interdependence leadership practices. In the final analysis, the findings revealed that, leadership at the case study school was manifested as spontaneous collaborated leadership practices through institutionalised practices embarked upon with intuitive working relationships.
- Full Text:
- Authors: Hamatwi, Isak
- Date: 2016
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: http://hdl.handle.net/10962/1275 , vital:20042
- Description: Leadership has been for long thought to centre on the actions of a positional head of the organisation crafting the vision and influencing followers’ behaviour based on his/her charisma and legal authority in a quest to achieve the set goals (Christie, 2010). However, contemporary views “emphasise leadership as relational” (Van der Mescht & Tyala, 2008, p. 226) and focuses more on the practice while taking form “in the interactions between leaders and followers” (Spillane, 2005, p. 146). Looking through the lens of distributed leadership and using the Grant’s (2008; 2012) model of teacher leadership as a data analytical tool, this research study aimed to explore the enactment of teacher leadership at a secondary school in the Ohangwena region, Namibia. The motivation of this research study was twofold; one, it was due to my personal interest in getting a deeper understanding of what constituted teacher leadership as a concept which is gaining momentum in the educational leadership discipline; two, it was due to the evident knowledge gap existing on the concept of teacher leadership as there seemed to be very less research done on the concept. Using observation schedules, survey questionnaires, semi-structured interview schedules and analysing documents as data collecting tools, the study was geared towards answering four research questions which were driving the study, namely; i) In what ways do teachers participate in the leadership activities of the school? ii) What is the nature of the relations of these leadership activities? iii) What factors that may constrain the leadership activities of these teachers? iv) How do the principal and the School Management Team (SMT) encourage teacher leadership at the school? The study was of a qualitative nature located in the interpretive paradigm. A purposive sampling method was used to select research participants The findings of the study indicated that the research participants had a general understanding of what teacher leadership entails. Teachers enacted leadership across the four zones of Grant’s (2008; 2012) model of teacher leadership, though with very limited teacher leadership enactment in zone four. Zones one, two and three proved to be the popular media of teacher leadership enactment wherein teachers led in their classrooms enforcing discipline, serving as guides and caregivers to their learners (zone one). Teachers then extended their leadership outside their classrooms where they served as decision makers, curriculum developers for knowledge enhancement through reflective teaching and sport coaches (zone two). In Zone three, teachers led in committees’ structures, as mentors of learners, policy makers and as models of good practice. Zone four was the least media of teacher leadership. The data pointed to a host of factors that prevented teachers to assume leadership at the case study school, namely; ignorance and fear for accountability, policy and regulatory limitations, time limitations, limited skills and teachers as barriers to teacher leadership in terms of apathy, lack of confidence, negative attitude and anti-social behaviours as well as professional jealous. Nevertheless, the principal and the SMT emerged as catalysts for teacher leadership at the school as they enabled teacher leadership in a number of ways, namely, through delegation, motivation, free choice, open engagement, moral support and interdependence leadership practices. In the final analysis, the findings revealed that, leadership at the case study school was manifested as spontaneous collaborated leadership practices through institutionalised practices embarked upon with intuitive working relationships.
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Exploring the course-led development of a learning network as a community of practice around a shared interest of rainwater harvesting and conservation agricultural practices: a case study in the Amathole District in the Eastern Cape, South Africa
- Authors: Weaver, Kim Nichole
- Date: 2016
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: http://hdl.handle.net/10962/1184 , vital:20032
- Description: South Africa has water and food security challenges, especially the Eastern Cape Province where there is a high level of poverty. These challenges place heavy pressure on the agricultural sector as it is the main user of the allocated water in the country. Rainwater harvesting and conservation (RWH&C) practices are explored as a response to these challenges, however information on these practices is not readily available to rural farmers. Agricultural extension has been moving from a top down approach towards a more participatory, collaborative process where what farmers need and want is considered. These participatory approaches need to be explored to enable change in farmer’s practice. This research forms part of a Water Resource Commission (WRC) project, Amanzi for Food. (Project K5/2277). The project has the explicit intention of supporting the use of two sets of WRC materials on RWH&C and expanding the learning of these practices through a courseled process within a learning network structure centred around an agricultural college. The network was established with a participatory, applied training of trainer’s course that supports and expands knowledge of RWH&C practices amongst network members from different groups within the sector; farmers, trainers, researchers and educators. My main research question was to investigate the process of cultivating a learning network amongst different agricultural actors through a course-led initiative to strengthen the engagement with RWH&C practices. To address this research I used focus group discussions, course observations, participant interviews, participant questionnaires and participant assignment progress to generate data. These data were analysed using Wenger’s theory of communities of practice to gauge levels of engagement, participation and learning. Main findings of the study are that the course-led activation of the learning network supported the community of practice members to share their personal experience and achieve social competence in the learning of RWH&C agricultural practices in their context.
- Full Text:
- Authors: Weaver, Kim Nichole
- Date: 2016
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: http://hdl.handle.net/10962/1184 , vital:20032
- Description: South Africa has water and food security challenges, especially the Eastern Cape Province where there is a high level of poverty. These challenges place heavy pressure on the agricultural sector as it is the main user of the allocated water in the country. Rainwater harvesting and conservation (RWH&C) practices are explored as a response to these challenges, however information on these practices is not readily available to rural farmers. Agricultural extension has been moving from a top down approach towards a more participatory, collaborative process where what farmers need and want is considered. These participatory approaches need to be explored to enable change in farmer’s practice. This research forms part of a Water Resource Commission (WRC) project, Amanzi for Food. (Project K5/2277). The project has the explicit intention of supporting the use of two sets of WRC materials on RWH&C and expanding the learning of these practices through a courseled process within a learning network structure centred around an agricultural college. The network was established with a participatory, applied training of trainer’s course that supports and expands knowledge of RWH&C practices amongst network members from different groups within the sector; farmers, trainers, researchers and educators. My main research question was to investigate the process of cultivating a learning network amongst different agricultural actors through a course-led initiative to strengthen the engagement with RWH&C practices. To address this research I used focus group discussions, course observations, participant interviews, participant questionnaires and participant assignment progress to generate data. These data were analysed using Wenger’s theory of communities of practice to gauge levels of engagement, participation and learning. Main findings of the study are that the course-led activation of the learning network supported the community of practice members to share their personal experience and achieve social competence in the learning of RWH&C agricultural practices in their context.
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Exploring the influence of learners’ participation in an after-school science enrichment programme on their disposition towards science: a case study of Khanya Maths and Science Club
- Authors: Agunbiade, Esther Arinola
- Date: 2016
- Subjects: Mathematics -- Study and teaching Science -- Study and teaching After-school programs Academic achievement
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: http://hdl.handle.net/10962/334 , vital:19949
- Description: The ongoing advancement of science and technology is creating an increasing need for more entrants into science oriented careers. However, numerous studies have fueled growing concerns regarding the poor achievement of learners in science. Over the years, science education researchers have emphasized the importance of the affective domain of learning as a central component of strategies used to address learners’ lack of interest and poor achievement in science. In the literature, the affective domain is characterized by constructs such as disposition, attitude, interest, and motivation. Studies showing a correlation between the affective domain and academic achievement suggest that nurturing a positive disposition towards science is an antecedent to learners’ improved science achievement and entering science fields. This study focuses on the ‘disposition’ aspect of the affective domain, and follows in the path of earlier studies which use the term interchangeably with ‘attitude’. Learners’ experiences in a particular science education environment influence the development of a positive or negative disposition towards science. However, there is a need to explore the factors in the learning environments which influence learners’ disposition towards science. Previous studies have shown that the informal science environment may influence learners’ disposition towards science. One example of an informal science environment is the Khanya Maths and Science Club, which is an after-school science and mathematics enrichment programme in Grahamstown, South Africa. This study explores the influence of learners’ participation in an informal science education environment on their dispositions towards science, using the case of the Khanya Maths and Science Club. This study views disposition through the constructivist-developmental lens. The community of practice elements from situated learning theory is drawn on to explore how learners’ disposition can be influenced by their interactions in the context of the Khanya Maths and Science Club. The pragmatic paradigm is adopted, which considers how well the research tools work to provide answers to the research questions. This thus, provides an avenue for exploring how learners’ disposition towards science is influenced and what factors influenced their shift in disposition through their participation in the club. A mixed-methods approach is employed when focusing on the affective domain sub-constructs of: enjoyment of science, interest in science and perception of science. These are sub-scales in the test of science related attitude (TOSRA) questionnaire which was adapted for use in measuring learners’ attitude before and after 16 weeks of participating in the science club. The particular mixed-methods approach selected can be summarized as quan QUAL since the method is primarily qualitative, but sequential with the quantitative phase preceding the qualitative phase. The TOSRA questionnaire was used as the quantitative data collection instrument while semi-structured interviews and learners’ journal entries were the qualitative data collection instruments. The results revealed significant shifts in learners’ perception of, interest in science and enjoyment of science though interest in science and enjoyment of science shifted appreciably in a positive direction more than the perception of science. It was also found that learners’ attitude towards science was influenced by; instructional characteristics, facilitators/environmental characteristics, learners making connection between science and everyday life and learners’ perceived difficulty of science. These factors variably influenced their attitude towards science in the club, corroborating what had been found in similar studies. This study corroborates what the literature offers for achieving effective outcomes in Afterschool science enrichment programmes. It contributes to the growing body of literature on features for quality outcomes in Afterschool science enrichment programmes. This study also makes a theoretical contribution to science education research particularly with regard to how the emergence of a community of practice framework in the club activities provide useful information for planning club activities and the analysis of learners’ evolving disposition towards science. Key words: Khanya Maths and Science Club, disposition, attitude, after-school enrichment programmes, constructivist-developmental approach, situated learning theory, community of practice, Test of Science Related Attitude (TOSRA).
- Full Text:
- Authors: Agunbiade, Esther Arinola
- Date: 2016
- Subjects: Mathematics -- Study and teaching Science -- Study and teaching After-school programs Academic achievement
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: http://hdl.handle.net/10962/334 , vital:19949
- Description: The ongoing advancement of science and technology is creating an increasing need for more entrants into science oriented careers. However, numerous studies have fueled growing concerns regarding the poor achievement of learners in science. Over the years, science education researchers have emphasized the importance of the affective domain of learning as a central component of strategies used to address learners’ lack of interest and poor achievement in science. In the literature, the affective domain is characterized by constructs such as disposition, attitude, interest, and motivation. Studies showing a correlation between the affective domain and academic achievement suggest that nurturing a positive disposition towards science is an antecedent to learners’ improved science achievement and entering science fields. This study focuses on the ‘disposition’ aspect of the affective domain, and follows in the path of earlier studies which use the term interchangeably with ‘attitude’. Learners’ experiences in a particular science education environment influence the development of a positive or negative disposition towards science. However, there is a need to explore the factors in the learning environments which influence learners’ disposition towards science. Previous studies have shown that the informal science environment may influence learners’ disposition towards science. One example of an informal science environment is the Khanya Maths and Science Club, which is an after-school science and mathematics enrichment programme in Grahamstown, South Africa. This study explores the influence of learners’ participation in an informal science education environment on their dispositions towards science, using the case of the Khanya Maths and Science Club. This study views disposition through the constructivist-developmental lens. The community of practice elements from situated learning theory is drawn on to explore how learners’ disposition can be influenced by their interactions in the context of the Khanya Maths and Science Club. The pragmatic paradigm is adopted, which considers how well the research tools work to provide answers to the research questions. This thus, provides an avenue for exploring how learners’ disposition towards science is influenced and what factors influenced their shift in disposition through their participation in the club. A mixed-methods approach is employed when focusing on the affective domain sub-constructs of: enjoyment of science, interest in science and perception of science. These are sub-scales in the test of science related attitude (TOSRA) questionnaire which was adapted for use in measuring learners’ attitude before and after 16 weeks of participating in the science club. The particular mixed-methods approach selected can be summarized as quan QUAL since the method is primarily qualitative, but sequential with the quantitative phase preceding the qualitative phase. The TOSRA questionnaire was used as the quantitative data collection instrument while semi-structured interviews and learners’ journal entries were the qualitative data collection instruments. The results revealed significant shifts in learners’ perception of, interest in science and enjoyment of science though interest in science and enjoyment of science shifted appreciably in a positive direction more than the perception of science. It was also found that learners’ attitude towards science was influenced by; instructional characteristics, facilitators/environmental characteristics, learners making connection between science and everyday life and learners’ perceived difficulty of science. These factors variably influenced their attitude towards science in the club, corroborating what had been found in similar studies. This study corroborates what the literature offers for achieving effective outcomes in Afterschool science enrichment programmes. It contributes to the growing body of literature on features for quality outcomes in Afterschool science enrichment programmes. This study also makes a theoretical contribution to science education research particularly with regard to how the emergence of a community of practice framework in the club activities provide useful information for planning club activities and the analysis of learners’ evolving disposition towards science. Key words: Khanya Maths and Science Club, disposition, attitude, after-school enrichment programmes, constructivist-developmental approach, situated learning theory, community of practice, Test of Science Related Attitude (TOSRA).
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Exploring the relationship between leadership styles and quality of work life: a case study of a Chinese- South African joint venture
- Authors: Handley, Rayne Cyla
- Date: 2016
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: http://hdl.handle.net/10962/4058 , vital:20597
- Description: This thesis employs a phenomenological qualitative research methodology to explore its research aims and objectives. It focuses on describing the various leadership styles and quality of work life (QWL) levels with reference to the Chinese-South African intercultural context. By doing so, it answers a primary exploratory research question; how does a particular leadership style influence QWL. By answering this question, this study will contribute to the understanding of the dynamics of Chinese organisations in South Africa. Furthermore, it will assist in creating greater intercultural synergy within the respective organisation. In order to explore the research question related to leadership and QWL, the thesis will begin by defining and describing the two concepts indigenously. In light of the research gap pertaining to African intercultural managerial contexts, as well as the rising Chinese and South Africa intercultural business environments, this case study demonstrates how leadership style is an important determining factor in QWL levels, both of the leaders as well as leader-raters within an intercultural context. China is South Africa’s largest trading partner and the signing of new agreements in 2015 will lead to enhanced China-Africa engagement at the macro and organisational level. China’s increasing engagement in both Africa and South Africa has been widely covered, but non-pejorative empirical research is needed to shed light on the organisational manifestations of China’s engagement. The study was conducted within the mining sector which is a key component of Chinese investment in, and trade with, South Africa. Through an in-depth content analysis which draws on coding and thematic concerns, quantification and description, this study finds that leaders directly influence QWL through relationships with their followers. Moreover, leaders indirectly have a bearing on QWL through the influence they have on organisational and work environment factors. Another finding is that leaders are inclined to describing higher levels of QWL and more transformational leadership styles. In addition, it is shown that executives (irrespective of leader or leader-rater status) were more likely to describe a high level of QWL and transformational leadership behaviours when compared to skilled level participants while the semi-skilled participants where least likely of all. Finally, it was found that the nature of the relationship between a leader and a follower is influenced by whether the said leader is a direct supervisor or if there is a large organisational level ‘gap’ between a leader and a leader- rater. It can also be said that leaders at higher organisational levels are expected to exhibit different leadership behaviours and meet different needs. Overall this study suggests that leaders need to be aware of the way in which the intercultural context can influence perceptions of subjective phenomena such as leadership effectiveness and QWL. The study concludes that leaders directly and indirectly play a key role in determining need satisfaction and QWL levels. To that extent, they ought to strategically adopt leadership practices that enhance need satisfaction and wellbeing in the workplace. Wellbeing and employee satisfaction are increasingly gaining importance within theory and literature related to QWL and has, importantly, also been shown to influence workplace attitudes and behaviours.
- Full Text:
- Authors: Handley, Rayne Cyla
- Date: 2016
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: http://hdl.handle.net/10962/4058 , vital:20597
- Description: This thesis employs a phenomenological qualitative research methodology to explore its research aims and objectives. It focuses on describing the various leadership styles and quality of work life (QWL) levels with reference to the Chinese-South African intercultural context. By doing so, it answers a primary exploratory research question; how does a particular leadership style influence QWL. By answering this question, this study will contribute to the understanding of the dynamics of Chinese organisations in South Africa. Furthermore, it will assist in creating greater intercultural synergy within the respective organisation. In order to explore the research question related to leadership and QWL, the thesis will begin by defining and describing the two concepts indigenously. In light of the research gap pertaining to African intercultural managerial contexts, as well as the rising Chinese and South Africa intercultural business environments, this case study demonstrates how leadership style is an important determining factor in QWL levels, both of the leaders as well as leader-raters within an intercultural context. China is South Africa’s largest trading partner and the signing of new agreements in 2015 will lead to enhanced China-Africa engagement at the macro and organisational level. China’s increasing engagement in both Africa and South Africa has been widely covered, but non-pejorative empirical research is needed to shed light on the organisational manifestations of China’s engagement. The study was conducted within the mining sector which is a key component of Chinese investment in, and trade with, South Africa. Through an in-depth content analysis which draws on coding and thematic concerns, quantification and description, this study finds that leaders directly influence QWL through relationships with their followers. Moreover, leaders indirectly have a bearing on QWL through the influence they have on organisational and work environment factors. Another finding is that leaders are inclined to describing higher levels of QWL and more transformational leadership styles. In addition, it is shown that executives (irrespective of leader or leader-rater status) were more likely to describe a high level of QWL and transformational leadership behaviours when compared to skilled level participants while the semi-skilled participants where least likely of all. Finally, it was found that the nature of the relationship between a leader and a follower is influenced by whether the said leader is a direct supervisor or if there is a large organisational level ‘gap’ between a leader and a leader- rater. It can also be said that leaders at higher organisational levels are expected to exhibit different leadership behaviours and meet different needs. Overall this study suggests that leaders need to be aware of the way in which the intercultural context can influence perceptions of subjective phenomena such as leadership effectiveness and QWL. The study concludes that leaders directly and indirectly play a key role in determining need satisfaction and QWL levels. To that extent, they ought to strategically adopt leadership practices that enhance need satisfaction and wellbeing in the workplace. Wellbeing and employee satisfaction are increasingly gaining importance within theory and literature related to QWL and has, importantly, also been shown to influence workplace attitudes and behaviours.
- Full Text:
Exploring the role of corrective feedback in helping Grade 8 learners to improve the accuracy of their written English: an action research case study
- Authors: Miranda, Zoachina Nangobe
- Date: 2016
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:2072 , http://hdl.handle.net/10962/d1021167
- Description: This action research study explored and analysed the role of teacher corrective feedback in helping Grade 8 learners to improve the accuracy of their written English as their second language. Therefore, the goals of this study were to examine the kind of language errors my grade 8 learners’ made in their writing, to find out whether these errors could be categorized linguistically, and to determine if they were errors, mistakes or lapses. The study further analysed how learners responded to my feedback, and also determined which feedback strategies worked best to help my learners deal with their errors, mistakes or lapses. This study set out to look at six learners from one Grade 8 class of 40 learners. The data were gathered from six written essay scripts, and each learner wrote four essay draft revisions. The learners’ written essays were analysed by means of checklists in order to identify the types and patterns of errors made. Errors such as punctuation, past tense verbs, spelling and vocabulary were identified, analysed and categorized to provide insights into reasons underlying the instances in which they were committed. The findings of this study showed that factors underlying learners’ written errors included mother-tongue interference, overgeneralization, fossilization, translation, lack of concentration, and carelessness. The findings further showed that corrective feedback on learners’ draft revisions provided them with extensive exposure and practice in English, enabled them to internalize language rules, and reduced the tendency to commit errors in their writing. The findings further suggest that procedures such as multiple-draft activities, indirect feedback, direct feedback, focused corrective feedback, error correction and written feedback with explicit corrective comments improved their levels of writing. Furthermore, putting these procedures into practice and reflecting critically on how to apply them helped enrich my own teaching practices and development in relation to the provision of corrective feedback to improve accuracy in learners’ writing. The findings are discussed in the context of the related literature. This study should be read by ESL teacher-trainers, ESL teachers, ESL student-teachers and ESL learners/students in general.
- Full Text:
- Authors: Miranda, Zoachina Nangobe
- Date: 2016
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:2072 , http://hdl.handle.net/10962/d1021167
- Description: This action research study explored and analysed the role of teacher corrective feedback in helping Grade 8 learners to improve the accuracy of their written English as their second language. Therefore, the goals of this study were to examine the kind of language errors my grade 8 learners’ made in their writing, to find out whether these errors could be categorized linguistically, and to determine if they were errors, mistakes or lapses. The study further analysed how learners responded to my feedback, and also determined which feedback strategies worked best to help my learners deal with their errors, mistakes or lapses. This study set out to look at six learners from one Grade 8 class of 40 learners. The data were gathered from six written essay scripts, and each learner wrote four essay draft revisions. The learners’ written essays were analysed by means of checklists in order to identify the types and patterns of errors made. Errors such as punctuation, past tense verbs, spelling and vocabulary were identified, analysed and categorized to provide insights into reasons underlying the instances in which they were committed. The findings of this study showed that factors underlying learners’ written errors included mother-tongue interference, overgeneralization, fossilization, translation, lack of concentration, and carelessness. The findings further showed that corrective feedback on learners’ draft revisions provided them with extensive exposure and practice in English, enabled them to internalize language rules, and reduced the tendency to commit errors in their writing. The findings further suggest that procedures such as multiple-draft activities, indirect feedback, direct feedback, focused corrective feedback, error correction and written feedback with explicit corrective comments improved their levels of writing. Furthermore, putting these procedures into practice and reflecting critically on how to apply them helped enrich my own teaching practices and development in relation to the provision of corrective feedback to improve accuracy in learners’ writing. The findings are discussed in the context of the related literature. This study should be read by ESL teacher-trainers, ESL teachers, ESL student-teachers and ESL learners/students in general.
- Full Text:
Eye of a needle
- Authors: Fick, Cornelia
- Date: 2016
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:6003 , http://hdl.handle.net/10962/d1021210
- Description: Most of my stories are about interpersonal relationships between the sexes, as well as intrapersonal processes, such as growing old. I have a deep connection to such themes because of my background as a general nurse and midwife; meeting too many abused women in hospitals, and the broader community. Because patterns of abuse tend to become invisible, I use experimental forms of storytelling as well as sharp, ironic and dark humour as a way to make this side of life more visible. My reading has shown me how experimental forms can render seemingly timeless or ageless topics in a fresh, vital way.
- Full Text:
- Authors: Fick, Cornelia
- Date: 2016
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:6003 , http://hdl.handle.net/10962/d1021210
- Description: Most of my stories are about interpersonal relationships between the sexes, as well as intrapersonal processes, such as growing old. I have a deep connection to such themes because of my background as a general nurse and midwife; meeting too many abused women in hospitals, and the broader community. Because patterns of abuse tend to become invisible, I use experimental forms of storytelling as well as sharp, ironic and dark humour as a way to make this side of life more visible. My reading has shown me how experimental forms can render seemingly timeless or ageless topics in a fresh, vital way.
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Four husbands for Ma Lindi: an exploration of the interaction between theatrical performance, gender, and sexuality in a South African urban context
- Authors: Vaughan, Clara
- Date: 2016
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/4610 , vital:20700
- Description: The thesis investigates the possibilities and limitations of theatre-making in providing a space for young people to collectively create, share, and interrogate understandings about sex, sexuality and gender. I use as a case study a theatremaking process I facilitated with a group of first year drama students at the Market Theatre Laboratory, in which we created a play called Four Husbands for Ma Lindi. The research analyses how this process interacted with the identities-in-becoming of the individual creators, and their engagement with the world, through a methodology that views them as experts on their own lives. There are three main arguments that I put forward in this thesis: the first is based on the experiences of healing, increased confidence and self-knowledge described by the participants as a result of sharing their personal stories in making the play. I argue that exploring autobiographical narratives through the aesthetic of theatre creates a group story that re-situates the narratives, the tellers and the witnesses in ways that can be productive for sexual and personal wellbeing, while also providing a counter-narrative that problematises the idea that sharing personal stories is always and necessarily a positive act. My second argument is that theatre-making, because it is an embodied performance pedagogy, is a constructive site in which to interrogate, deconstruct and subvert embedded gender norms and values, which are learnt and reiterated in the body. My third argument considers the relationship between theatre and change that is suggested by the findings of the research. In an analysis of the responses of the participants, I contend that theatre's potential for creating change in the socio-cultural domain lies in its ability to carve out spaces for improvisation, rather than to serve as a rehearsal for the real world. This is the position from which I then consider my ethics of practice and the role and responsibility of the facilitator in processes that view theatre-making as a critical performance pedagogy.
- Full Text:
- Authors: Vaughan, Clara
- Date: 2016
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/4610 , vital:20700
- Description: The thesis investigates the possibilities and limitations of theatre-making in providing a space for young people to collectively create, share, and interrogate understandings about sex, sexuality and gender. I use as a case study a theatremaking process I facilitated with a group of first year drama students at the Market Theatre Laboratory, in which we created a play called Four Husbands for Ma Lindi. The research analyses how this process interacted with the identities-in-becoming of the individual creators, and their engagement with the world, through a methodology that views them as experts on their own lives. There are three main arguments that I put forward in this thesis: the first is based on the experiences of healing, increased confidence and self-knowledge described by the participants as a result of sharing their personal stories in making the play. I argue that exploring autobiographical narratives through the aesthetic of theatre creates a group story that re-situates the narratives, the tellers and the witnesses in ways that can be productive for sexual and personal wellbeing, while also providing a counter-narrative that problematises the idea that sharing personal stories is always and necessarily a positive act. My second argument is that theatre-making, because it is an embodied performance pedagogy, is a constructive site in which to interrogate, deconstruct and subvert embedded gender norms and values, which are learnt and reiterated in the body. My third argument considers the relationship between theatre and change that is suggested by the findings of the research. In an analysis of the responses of the participants, I contend that theatre's potential for creating change in the socio-cultural domain lies in its ability to carve out spaces for improvisation, rather than to serve as a rehearsal for the real world. This is the position from which I then consider my ethics of practice and the role and responsibility of the facilitator in processes that view theatre-making as a critical performance pedagogy.
- Full Text:
FRAME: frame routing and manipulation engine
- Authors: Pennefather, Sean Niel
- Date: 2016
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/3608 , vital:20529
- Description: This research reports on the design and implementation of FRAME: an embedded hardware network processing platform designed to perform network frame manipulation and monitoring. This is possible at line speeds compliant with the IEEE 802.3 Ethernet standard. The system provides frame manipulation functionality to aid in the development and implementation of network testing environments. Platform cost and ease of use are both considered during design resulting in fabrication of hardware and the development of Link, a Domain Specific Language used to create custom applications that are compatible with the platform. Functionality of the resulting platform is shown through conformance testing of designed modules and application examples. Throughput testing showed that the peak throughput achievable by the platform is limited to 86.4 Mbit/s, comparable to commodity 100 Mbit hardware and the total cost of the prototype platform ranged between $220 and $254.
- Full Text:
- Authors: Pennefather, Sean Niel
- Date: 2016
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/3608 , vital:20529
- Description: This research reports on the design and implementation of FRAME: an embedded hardware network processing platform designed to perform network frame manipulation and monitoring. This is possible at line speeds compliant with the IEEE 802.3 Ethernet standard. The system provides frame manipulation functionality to aid in the development and implementation of network testing environments. Platform cost and ease of use are both considered during design resulting in fabrication of hardware and the development of Link, a Domain Specific Language used to create custom applications that are compatible with the platform. Functionality of the resulting platform is shown through conformance testing of designed modules and application examples. Throughput testing showed that the peak throughput achievable by the platform is limited to 86.4 Mbit/s, comparable to commodity 100 Mbit hardware and the total cost of the prototype platform ranged between $220 and $254.
- Full Text:
Fusing fact and fiction: biography and autobiography in the novels of Virginia Woolf
- Authors: White, Joshua Craig
- Date: 2016
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/4005 , vital:20580
- Description: Virginia Woolf was noted for a preoccupation with the genre of life-writing throughout her career. Her aims when it came to reshaping the nature of biographical and autobiographical literature were numerous. She veered away from the aggrandising and patriarchal methods with which Victorian biographers tended to depict their subjects. She increased the focus on women in life-writing, examining and subverting traditionally prescribed gender roles prevalent in both her society and the literature that reflected it, and advocating a balance between male and female patterns of thinking. She also devised a method of incorporating both basic biographical fact and aspects of fiction into life-writing in order to approach a more truthful depiction of a subject’s personality or character. This method is linked to the aforementioned balance of gendered thought patterns, since Woolf often aligns factuality with male thinking and the contrasting qualities of fiction, such as intuition, ambivalence and perspicacity, with female thinking. This thesis examines three novels which demonstrate Woolf’s constant preoccupation with combining fact and fiction in order to capture the essence of personality. In her debut novel, The Voyage Out, she presents Rachel Vinrace, who must achieve a balance of male-oriented fact with female-oriented insight in order to fashion a sufficient identity for herself and to identify others in a selective and judicious manner, thus being simultaneously autobiographical and biographical. In Orlando, Woolf explicitly subverts the traditional Victorian biography by depicting Vita Sackville-West as a man who transforms into a woman and remains living for over 400 years. In presenting such a character, Woolf posits that personality consists of and is influenced by myriad aspects of a person’s life that cannot be documented in the restrictive manner employed by Victorian biographers. Orlando’s essence being obfuscated by manifold “selves” attests to Woolf problematizing attempts to attain such an essence. The same challenge is particularly important in her autobiographical novel, To the Lighthouse, in which she transposes the traumas of her own life into a fictitious narrative in order to achieve catharsis for her and her readers, and to present the difficulty in capturing the essence of character. The conclusion that Woolf eventually posits is that personality cannot be reduced to an essence, but rather that it consists of idiosyncrasies that are various, intertwining, and capricious.
- Full Text:
- Authors: White, Joshua Craig
- Date: 2016
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/4005 , vital:20580
- Description: Virginia Woolf was noted for a preoccupation with the genre of life-writing throughout her career. Her aims when it came to reshaping the nature of biographical and autobiographical literature were numerous. She veered away from the aggrandising and patriarchal methods with which Victorian biographers tended to depict their subjects. She increased the focus on women in life-writing, examining and subverting traditionally prescribed gender roles prevalent in both her society and the literature that reflected it, and advocating a balance between male and female patterns of thinking. She also devised a method of incorporating both basic biographical fact and aspects of fiction into life-writing in order to approach a more truthful depiction of a subject’s personality or character. This method is linked to the aforementioned balance of gendered thought patterns, since Woolf often aligns factuality with male thinking and the contrasting qualities of fiction, such as intuition, ambivalence and perspicacity, with female thinking. This thesis examines three novels which demonstrate Woolf’s constant preoccupation with combining fact and fiction in order to capture the essence of personality. In her debut novel, The Voyage Out, she presents Rachel Vinrace, who must achieve a balance of male-oriented fact with female-oriented insight in order to fashion a sufficient identity for herself and to identify others in a selective and judicious manner, thus being simultaneously autobiographical and biographical. In Orlando, Woolf explicitly subverts the traditional Victorian biography by depicting Vita Sackville-West as a man who transforms into a woman and remains living for over 400 years. In presenting such a character, Woolf posits that personality consists of and is influenced by myriad aspects of a person’s life that cannot be documented in the restrictive manner employed by Victorian biographers. Orlando’s essence being obfuscated by manifold “selves” attests to Woolf problematizing attempts to attain such an essence. The same challenge is particularly important in her autobiographical novel, To the Lighthouse, in which she transposes the traumas of her own life into a fictitious narrative in order to achieve catharsis for her and her readers, and to present the difficulty in capturing the essence of character. The conclusion that Woolf eventually posits is that personality cannot be reduced to an essence, but rather that it consists of idiosyncrasies that are various, intertwining, and capricious.
- Full Text:
Genetic and biological characterisation of a novel South African Cydia pomonella granulovirus (CpGV-SA) isolate
- Motsoeneng, Boitumelo Madika
- Authors: Motsoeneng, Boitumelo Madika
- Date: 2016
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:20503 , http://hdl.handle.net/10962/d1021266
- Description: The codling moth, Cydia pomonella (L.) (Lepidoptera: Tortricidae), is the primary pest of pome fruit cultivated worldwide. The control of this insect pest has been dependent on the frequent use of broad-spectrum chemical pesticides, which has led to the development of resistance in pest populations and negative effects on human health and the environment. The Betabaculovirus of C. pomonella has successfully been applied as a biological control agent in integrated pest management (IPM) programmes for the suppression of pest populations worldwide. Previously, all Cydia pomonella granulovirus (CpGV) biopesticides were based on a Mexican isolate (CpGV-M) and although these products are highly efficient at controlling C. pomonella, resistance cases have been reported across Europe. The identification of novel CpGV isolates as additional or alternative control agents to manage resistance is therefore necessary. This study aimed to genetically and biologically characterise a novel South African C. pomonella granulovirus isolate and to test its virulence against neonate larvae. Based on the morphology of the occlusion bodies observed using transmission electron microscopy, granuloviruses were recovered from diseased and dead larvae collected from an orchard in South Africa where no virus applications had been made. DNA was extracted and the identification of the isolated granulovirus was achieved through the PCR amplification and sequencing of the lef-8, lef-9, granulin and egt genes. Submission of the gene sequences to BLAST revealed high percentage identities to sequences from various CpGV isolates, resulting in the naming of the isolate in this study as the South African Cydia pomonella granulovirus (CpGV-SA) isolate. Phylogenetic analysis based on the single nucleotide polymorphisms (SNPs) detected in the lef-8, lef-9 and granulin nucleotide sequences grouped the South African isolate with CpGV-E2 (genome type B) and CpGV-S (genome type E). The CpGV-SA isolate was further genetically characterised by restriction endonuclease analysis and complete sequencing of the genomic DNA. Differences were observed for the BamHI, EcoRI, PstI and XhoI profiles of CpGV-SA in comparison to the respective profiles generated for CpGV-M extracted from a biopesticide, Carpovirusine® (Arysta Lifescience, France). Several genetic variations between the complete genome sequence of CpGV-SA and the reference isolate, CpGV-M1, as well as a recent genome submission of CpGV-M, both representing genome type A were observed. The complete genome analysis confirmed that CpGV-SA is genetically different from the Mexican CpGV isolate, used in thedevelopment of most biopesticides. In silico restriction profiles of the genome sequence obtained for CpGV-SA and genome sequences of genetically different CpGV isolates originating from Mexico (M1 and M), England (E2), Canada (S) and Iran (I12 and I07), available on the NCBI’s GenBank database confirmed that CpGV-SA is of mixed genotypes. Furthermore, the South African isolate shared the single common difference found in the pe38 gene of resistance overcoming isolates, which was the absence of an internal 24 nucleotide repeat present in CpGV-M1. In addition to the common difference, SNPs detected in the pe38 gene grouped the isolate with the CpGV-S isolate, suggesting that the CpGV-SA isolate is predominantly of genome type E. To determine the biological activity of CpGV-SA against neonate C. pomonella larvae, surface bioassays were conducted alongside CpGV-M (Carpovirusine®) bioassays. The LC50 and LC90 values for the South African isolate were 1.6 × 103 and 1.2 × 105 OBs/ml respectively. The LT50 was determined to be 135 hours. These values were similar to the values obtained for CpGV-M (Carpovirusine®). The results in this study suggest that a novel South African CpGV isolate of mixed genotypes, potentially able to overcome resistance in C. pomonella, with biological activity similar to CpGV-M (Carpovirusine®) and important for the control of C. pomonella was recovered. The CpGV-SA isolate could therefore potentially be developed into a biopesticide for use in resistance management strategies against C. pomonella populations in South Africa.
- Full Text:
- Authors: Motsoeneng, Boitumelo Madika
- Date: 2016
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:20503 , http://hdl.handle.net/10962/d1021266
- Description: The codling moth, Cydia pomonella (L.) (Lepidoptera: Tortricidae), is the primary pest of pome fruit cultivated worldwide. The control of this insect pest has been dependent on the frequent use of broad-spectrum chemical pesticides, which has led to the development of resistance in pest populations and negative effects on human health and the environment. The Betabaculovirus of C. pomonella has successfully been applied as a biological control agent in integrated pest management (IPM) programmes for the suppression of pest populations worldwide. Previously, all Cydia pomonella granulovirus (CpGV) biopesticides were based on a Mexican isolate (CpGV-M) and although these products are highly efficient at controlling C. pomonella, resistance cases have been reported across Europe. The identification of novel CpGV isolates as additional or alternative control agents to manage resistance is therefore necessary. This study aimed to genetically and biologically characterise a novel South African C. pomonella granulovirus isolate and to test its virulence against neonate larvae. Based on the morphology of the occlusion bodies observed using transmission electron microscopy, granuloviruses were recovered from diseased and dead larvae collected from an orchard in South Africa where no virus applications had been made. DNA was extracted and the identification of the isolated granulovirus was achieved through the PCR amplification and sequencing of the lef-8, lef-9, granulin and egt genes. Submission of the gene sequences to BLAST revealed high percentage identities to sequences from various CpGV isolates, resulting in the naming of the isolate in this study as the South African Cydia pomonella granulovirus (CpGV-SA) isolate. Phylogenetic analysis based on the single nucleotide polymorphisms (SNPs) detected in the lef-8, lef-9 and granulin nucleotide sequences grouped the South African isolate with CpGV-E2 (genome type B) and CpGV-S (genome type E). The CpGV-SA isolate was further genetically characterised by restriction endonuclease analysis and complete sequencing of the genomic DNA. Differences were observed for the BamHI, EcoRI, PstI and XhoI profiles of CpGV-SA in comparison to the respective profiles generated for CpGV-M extracted from a biopesticide, Carpovirusine® (Arysta Lifescience, France). Several genetic variations between the complete genome sequence of CpGV-SA and the reference isolate, CpGV-M1, as well as a recent genome submission of CpGV-M, both representing genome type A were observed. The complete genome analysis confirmed that CpGV-SA is genetically different from the Mexican CpGV isolate, used in thedevelopment of most biopesticides. In silico restriction profiles of the genome sequence obtained for CpGV-SA and genome sequences of genetically different CpGV isolates originating from Mexico (M1 and M), England (E2), Canada (S) and Iran (I12 and I07), available on the NCBI’s GenBank database confirmed that CpGV-SA is of mixed genotypes. Furthermore, the South African isolate shared the single common difference found in the pe38 gene of resistance overcoming isolates, which was the absence of an internal 24 nucleotide repeat present in CpGV-M1. In addition to the common difference, SNPs detected in the pe38 gene grouped the isolate with the CpGV-S isolate, suggesting that the CpGV-SA isolate is predominantly of genome type E. To determine the biological activity of CpGV-SA against neonate C. pomonella larvae, surface bioassays were conducted alongside CpGV-M (Carpovirusine®) bioassays. The LC50 and LC90 values for the South African isolate were 1.6 × 103 and 1.2 × 105 OBs/ml respectively. The LT50 was determined to be 135 hours. These values were similar to the values obtained for CpGV-M (Carpovirusine®). The results in this study suggest that a novel South African CpGV isolate of mixed genotypes, potentially able to overcome resistance in C. pomonella, with biological activity similar to CpGV-M (Carpovirusine®) and important for the control of C. pomonella was recovered. The CpGV-SA isolate could therefore potentially be developed into a biopesticide for use in resistance management strategies against C. pomonella populations in South Africa.
- Full Text:
Genetic structure and biogeography of three wrasse species (Labridae) within the Western Indian Ocean
- Authors: Mayekiso, Sisanda
- Date: 2016
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/1114 , vital:20021
- Description: The biogeography of wrasses within the Western Indian Ocean (WIO) is poorly understood, with regard to origins and genetic differentiation or connectivity among the regions of the WIO. This region is a good model for studying the influence of physical complexities and biogeographic breaks in shaping patterns of differentiation in wrasses. Three reef-associated fish species, Cheilio inermis, Thalassoma hebraicum and T. lunare, were selected to examine the factors that have influenced patterns of differentiation across the WIO. Each species was sampled from various localities of the WIO, the Red Sea and Indo-West Pacific Islands. Sequence data were generated from two mitochondrial gene fragments (cytochrome b and ATPase 6) and one nuclear locus (the first intron of the ribosomal protein S7 gene). Genetic analyses were used to calculate genetic diversity indices within species, which were then compared among species. The relationships among haplotypes and alleles were constructed using median-joining networks. Where necessary, neighbour-joining trees (NJ) were constructed to examine relationships among haplotypes and alleles for the Thalassoma species. Population structure was analysed using AMOVA and pairwise ФST to compare and calculate differentiation between the WIO localities. Mismatch distributions were used to examine population growth and decline or stability, and demographic parameters were used to calculate time of population expansion. There was high haplotype (h = 0.88 to 0.98) and low nucleotide diversities (π = 0.003 to 0.008) among all species for mitochondrial markers. For S7 intron I, high allelic (A = 0.95 to 0.98) and low nucleotide diversities (π = 0.002 to 0.014) were observed for all species. The pairwise ФST values revealed little to great (ФST = -0.02 to 0.67) genetic differentiation between localities, across all species for the three gene regions. The pairwise comparisons indicated the differentiation in C. inermis of Tanzania and Kenya from Mozambique and Nosy Be (Madagascar). The widespread C. inermis also revealed the differentiation of Kenya and Tanzania. For C. inermis, the AMOVAs of ATPase 6 and cytochrome b data indicated high differentiation among defined locality groups. The groups were defined according to geographic proximity. However, the AMOVA of the nuclear gene (S7 intron I) did not find variation among defined locality groups. Cheilio inermis revealed a sequence divergence of 0.4%. The divergence that was found in C. inermis was not enough to suggest a cryptic species within the WIO. Overall, the widespread and monotypic C. inermis revealed genetic differentiation within the WIO. Thalassoma hebraicum generally revealed little genetic differentiation across the WIO. The AMOVAs of the three gene regions showed no variation among specimens of the defined locality groups. However, some differentiation was found between localities. The pairwise comparisons of T. hebraicum revealed the differentiation of Seychelles from the African mainland and Madagascar. Southern Africa was observed to be differentiated from Nosy Be and Zanzibar. The observed differentiation could be caused by oceanic barriers such as the South Equatorial Current (SEQC), East African Coastal Current (EACC), and the Comoros Gyres and eddies in the Mozambique Channel, and Agulhas Current. Thalassoma lunare revealed genetic isolation between the WIO and the Red Sea as well as within the WIO. The genetic isolation between the WIO and the Red Sea is probably due to the historical isolation by the Bab al Mandab and contemporary barriers such as the cold upwelling cells in Somalia. The differentiation of Maldives from the African mainland and Seychelles could be due to distance and the upwelling cells created by monsoon winds. Mismatch distributions suggested that C. inermis and T. hebraicum had undergone demographic expansion during the Pleistocene (92 678 to 40 219 years ago). The results of the current study are similar to those from previous studies of WIO reef fish species, and the results of the present study could have potential implications for conservation and fisheries management. Single genetic markers and single species studies do not detect all barriers to dispersal in the WIO, thus they are insufficient to inform conservation management. Thus, the use of multispecies and genetic markers in the current study can be adopted by other studies of the marine taxa of the WIO.
- Full Text:
- Authors: Mayekiso, Sisanda
- Date: 2016
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/1114 , vital:20021
- Description: The biogeography of wrasses within the Western Indian Ocean (WIO) is poorly understood, with regard to origins and genetic differentiation or connectivity among the regions of the WIO. This region is a good model for studying the influence of physical complexities and biogeographic breaks in shaping patterns of differentiation in wrasses. Three reef-associated fish species, Cheilio inermis, Thalassoma hebraicum and T. lunare, were selected to examine the factors that have influenced patterns of differentiation across the WIO. Each species was sampled from various localities of the WIO, the Red Sea and Indo-West Pacific Islands. Sequence data were generated from two mitochondrial gene fragments (cytochrome b and ATPase 6) and one nuclear locus (the first intron of the ribosomal protein S7 gene). Genetic analyses were used to calculate genetic diversity indices within species, which were then compared among species. The relationships among haplotypes and alleles were constructed using median-joining networks. Where necessary, neighbour-joining trees (NJ) were constructed to examine relationships among haplotypes and alleles for the Thalassoma species. Population structure was analysed using AMOVA and pairwise ФST to compare and calculate differentiation between the WIO localities. Mismatch distributions were used to examine population growth and decline or stability, and demographic parameters were used to calculate time of population expansion. There was high haplotype (h = 0.88 to 0.98) and low nucleotide diversities (π = 0.003 to 0.008) among all species for mitochondrial markers. For S7 intron I, high allelic (A = 0.95 to 0.98) and low nucleotide diversities (π = 0.002 to 0.014) were observed for all species. The pairwise ФST values revealed little to great (ФST = -0.02 to 0.67) genetic differentiation between localities, across all species for the three gene regions. The pairwise comparisons indicated the differentiation in C. inermis of Tanzania and Kenya from Mozambique and Nosy Be (Madagascar). The widespread C. inermis also revealed the differentiation of Kenya and Tanzania. For C. inermis, the AMOVAs of ATPase 6 and cytochrome b data indicated high differentiation among defined locality groups. The groups were defined according to geographic proximity. However, the AMOVA of the nuclear gene (S7 intron I) did not find variation among defined locality groups. Cheilio inermis revealed a sequence divergence of 0.4%. The divergence that was found in C. inermis was not enough to suggest a cryptic species within the WIO. Overall, the widespread and monotypic C. inermis revealed genetic differentiation within the WIO. Thalassoma hebraicum generally revealed little genetic differentiation across the WIO. The AMOVAs of the three gene regions showed no variation among specimens of the defined locality groups. However, some differentiation was found between localities. The pairwise comparisons of T. hebraicum revealed the differentiation of Seychelles from the African mainland and Madagascar. Southern Africa was observed to be differentiated from Nosy Be and Zanzibar. The observed differentiation could be caused by oceanic barriers such as the South Equatorial Current (SEQC), East African Coastal Current (EACC), and the Comoros Gyres and eddies in the Mozambique Channel, and Agulhas Current. Thalassoma lunare revealed genetic isolation between the WIO and the Red Sea as well as within the WIO. The genetic isolation between the WIO and the Red Sea is probably due to the historical isolation by the Bab al Mandab and contemporary barriers such as the cold upwelling cells in Somalia. The differentiation of Maldives from the African mainland and Seychelles could be due to distance and the upwelling cells created by monsoon winds. Mismatch distributions suggested that C. inermis and T. hebraicum had undergone demographic expansion during the Pleistocene (92 678 to 40 219 years ago). The results of the current study are similar to those from previous studies of WIO reef fish species, and the results of the present study could have potential implications for conservation and fisheries management. Single genetic markers and single species studies do not detect all barriers to dispersal in the WIO, thus they are insufficient to inform conservation management. Thus, the use of multispecies and genetic markers in the current study can be adopted by other studies of the marine taxa of the WIO.
- Full Text:
Geochemical exploration for copper - cobalt in the Democratic Republic of Congo, Central African Copperbelt: a case study on PR851
- Authors: Katombe-Kisumbule, Paul
- Date: 2016
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/3035 , vital:20354
- Description: The PR851 licence area is located at about 80 km west from the town of Likasi in the district of Haut-Katanga and 175 km north-west of Lubumbashi, the capital city of Katanga Province in the Democratic Republic of Congo. The exploration licence was granted by the government of the Democratic Republic of Congo to First Quantum Minerals Ltd through its Congolese subsidiary Compagnie Minière de Sakania Sprl (CoMiSa Sprl) under certificate N˚ CAMI/CR/70/2003 on the 10th of October 2003 for a period of 5 years with a possibility of renewal for 3 years in respect to the new Congolese mining code. The PR851 area lies on fragments of Mines Subgroup rocks of the Roan Group in the Congolese Copperbelt where most of the Cu-Co and stratiform-stratabound deposits such as Kipushi, Ruashi-Etoile, Kinsevere, Kipoi, Luishya, Luswishi, Shituru, Kamoya, Kambove, Tenke- Fungurume, Shinkolobwe, Swambo, Mindingi and Kamoto among others are found. During the 20th century, the Union Minière du Haut Katanga (U.M.H.K.) undertook mineral exploration in the Congolese Copperbelt and numerous copper- and cobalt-occurrences were identified (for instance Kibamba copper occurrence in PR851 area). From 2003, the Compagnie Minière de Sakania Sprl initiated a grassroots exploration program in PR851 area and geochemical exploration survey as one of the mineral exploration tools was implemented to aim at detecting copper and cobalt concentration in soil. The B horizon of the thick tropical soil in the area was sampled and soil samples were sent to Genalysis laboratories in Johannesburg, Republic of South Africa for main chemical analysis of Cu and Co only, whereas 10% of analyzed samples were dispatched to Perth, Western Australia for quality control analysis. Thresholds for anomalies of copper and cobalt were defined by literature comparison, standard deviations and spatial analysis. The anomalies were tested at a later stage by reverse circulation / diamond drilling during the year of 2005 to 2008 and the Cu-Co resources were estimated by Digital Mining Services of Harare, Zimbabwe in the year of 2008. Geological logging of chips from reverse circulation and diamond drill cores revealed that copper mineralization is represented by malachite, chrysocolla, chalcopyrite and bornite whereas cobalt mineralization appeared in form of heterogenite. The source of supergene mineralization remains unknown. Recommendations have been made to undertake more geological exploration work in order to fully investigate the geological setting and structural architecture of the region, which may result in a better understanding of the Cu-Co mineralization system and ore genesis. The latter has been no consensus up-to-date and different theories have been proposed to discuss the ore genesis, including syn- and dia- genetic, synorogenic and sulphide remobilization to late-to-post- orogenic Cu-Zn-Pb Kipushi-type deposit. However, geological observations favored that the diagenetic and syngenetic models are applicable to numerous deposits in the Central African Copperbelt.
- Full Text:
- Authors: Katombe-Kisumbule, Paul
- Date: 2016
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/3035 , vital:20354
- Description: The PR851 licence area is located at about 80 km west from the town of Likasi in the district of Haut-Katanga and 175 km north-west of Lubumbashi, the capital city of Katanga Province in the Democratic Republic of Congo. The exploration licence was granted by the government of the Democratic Republic of Congo to First Quantum Minerals Ltd through its Congolese subsidiary Compagnie Minière de Sakania Sprl (CoMiSa Sprl) under certificate N˚ CAMI/CR/70/2003 on the 10th of October 2003 for a period of 5 years with a possibility of renewal for 3 years in respect to the new Congolese mining code. The PR851 area lies on fragments of Mines Subgroup rocks of the Roan Group in the Congolese Copperbelt where most of the Cu-Co and stratiform-stratabound deposits such as Kipushi, Ruashi-Etoile, Kinsevere, Kipoi, Luishya, Luswishi, Shituru, Kamoya, Kambove, Tenke- Fungurume, Shinkolobwe, Swambo, Mindingi and Kamoto among others are found. During the 20th century, the Union Minière du Haut Katanga (U.M.H.K.) undertook mineral exploration in the Congolese Copperbelt and numerous copper- and cobalt-occurrences were identified (for instance Kibamba copper occurrence in PR851 area). From 2003, the Compagnie Minière de Sakania Sprl initiated a grassroots exploration program in PR851 area and geochemical exploration survey as one of the mineral exploration tools was implemented to aim at detecting copper and cobalt concentration in soil. The B horizon of the thick tropical soil in the area was sampled and soil samples were sent to Genalysis laboratories in Johannesburg, Republic of South Africa for main chemical analysis of Cu and Co only, whereas 10% of analyzed samples were dispatched to Perth, Western Australia for quality control analysis. Thresholds for anomalies of copper and cobalt were defined by literature comparison, standard deviations and spatial analysis. The anomalies were tested at a later stage by reverse circulation / diamond drilling during the year of 2005 to 2008 and the Cu-Co resources were estimated by Digital Mining Services of Harare, Zimbabwe in the year of 2008. Geological logging of chips from reverse circulation and diamond drill cores revealed that copper mineralization is represented by malachite, chrysocolla, chalcopyrite and bornite whereas cobalt mineralization appeared in form of heterogenite. The source of supergene mineralization remains unknown. Recommendations have been made to undertake more geological exploration work in order to fully investigate the geological setting and structural architecture of the region, which may result in a better understanding of the Cu-Co mineralization system and ore genesis. The latter has been no consensus up-to-date and different theories have been proposed to discuss the ore genesis, including syn- and dia- genetic, synorogenic and sulphide remobilization to late-to-post- orogenic Cu-Zn-Pb Kipushi-type deposit. However, geological observations favored that the diagenetic and syngenetic models are applicable to numerous deposits in the Central African Copperbelt.
- Full Text: