Between drones and al-Shabaab: United States extra-judicial killings in Somalia, sovereignty and the future of liberal intervention
- Authors: Koloko, Mojalefa
- Date: 2019
- Subjects: Somalia -- Politics and government -- 1991- , Somalia -- History -- 1991- , Somalia -- Foreign relations -- United States , Somalia -- Foreign relations -- 1991- , Military assistance, American -- Somalia , Extrajudicial exeutions -- Somalia , Shabaab (Organization)
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/67657 , vital:29125
- Description: This study examines the nature of the United States intervention in Somalia, specifically the use of drone strikes that first targeted the militant Sunni Islamist transnational group, al-Qaeda, which claimed responsibility for the 11 September 2001 attacks on the United States, and now target the Somali organisation, Harakat al-Shabaab al-Mujahidin, commonly known as al-Shabaab. The use of drone strikes in the US led war on terror has raised concerns about sovereignty as the extra-judicial killings are conducted without the consent of the concerned states. Furthermore, drone strikes also raise questions about the processes of liberal intervention as the US conducts them without the approval of the United Nations Security Council. It is argued in this study that what is understood to be the “golden era” of liberal interventionism is a legacy of the post-Cold War unipolar dominance of the United States in global governance and security. It is argued that US unipolarity was accompanied by a shifting perception regarding the security position of weak states, whose weakness becomes understood as a source of global insecurity. This perception that so called “weak” and “fragile” states are sources of threats is a departure in International Relations theory, because the discipline is historically preoccupied with studying the actions of powerful states and their consequence for the global order. It is argued that the discourse on the war on terror, and its focus on “failed states” as breeding grounds for alleged terrorists, represents the height of the repositioning of less powerful states from a peripheral status in IR analysis and practice, to their current position that are now being represented as core sources of threat to international peace and security. Through life history interviews with Somali nationals in Grahamstown, Port Elizabeth and Uitenhage, South Africa, the study examines the consequences of US actions from the eyes of Somali people. The findings of this study show that despite all the controversy surrounding the legitimacy of the war on terror, the manner in which it is conducted, as well as the tactics that it employs, the majority of Somali participants showed an overwhelming support for the US intervention. Participants expressed support for the US extra-judicial killings because they are understood to undermine al-Shabaab strength which is a major source of insecurity. The study also shows that the lack of necessary collaboration between the US intelligence and the Somali ground forces has resulted in high numbers of civilian deaths, which participants fear can be used by al-Shabaab to recruit and radicalise more Somalis. The study also shows that most Somalis resent the presence of the African Union Mission in Somalia because Kenya and Ethiopia are seen as 10 pursuing national interests that are not invested in Somali peace and stability. The study concludes that US extra-judicial killings have failed to constrain the actions of al-Shabaab. Somalis expressed that the leadership of current president, Mohamed Abdullahi Mohamed Farmaajo, holds the unique possibilities of creating national unity that rises above clan divisions and the radical Jihadist ideology of al-Shabaab.
- Full Text:
- Date Issued: 2019
- Authors: Koloko, Mojalefa
- Date: 2019
- Subjects: Somalia -- Politics and government -- 1991- , Somalia -- History -- 1991- , Somalia -- Foreign relations -- United States , Somalia -- Foreign relations -- 1991- , Military assistance, American -- Somalia , Extrajudicial exeutions -- Somalia , Shabaab (Organization)
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/67657 , vital:29125
- Description: This study examines the nature of the United States intervention in Somalia, specifically the use of drone strikes that first targeted the militant Sunni Islamist transnational group, al-Qaeda, which claimed responsibility for the 11 September 2001 attacks on the United States, and now target the Somali organisation, Harakat al-Shabaab al-Mujahidin, commonly known as al-Shabaab. The use of drone strikes in the US led war on terror has raised concerns about sovereignty as the extra-judicial killings are conducted without the consent of the concerned states. Furthermore, drone strikes also raise questions about the processes of liberal intervention as the US conducts them without the approval of the United Nations Security Council. It is argued in this study that what is understood to be the “golden era” of liberal interventionism is a legacy of the post-Cold War unipolar dominance of the United States in global governance and security. It is argued that US unipolarity was accompanied by a shifting perception regarding the security position of weak states, whose weakness becomes understood as a source of global insecurity. This perception that so called “weak” and “fragile” states are sources of threats is a departure in International Relations theory, because the discipline is historically preoccupied with studying the actions of powerful states and their consequence for the global order. It is argued that the discourse on the war on terror, and its focus on “failed states” as breeding grounds for alleged terrorists, represents the height of the repositioning of less powerful states from a peripheral status in IR analysis and practice, to their current position that are now being represented as core sources of threat to international peace and security. Through life history interviews with Somali nationals in Grahamstown, Port Elizabeth and Uitenhage, South Africa, the study examines the consequences of US actions from the eyes of Somali people. The findings of this study show that despite all the controversy surrounding the legitimacy of the war on terror, the manner in which it is conducted, as well as the tactics that it employs, the majority of Somali participants showed an overwhelming support for the US intervention. Participants expressed support for the US extra-judicial killings because they are understood to undermine al-Shabaab strength which is a major source of insecurity. The study also shows that the lack of necessary collaboration between the US intelligence and the Somali ground forces has resulted in high numbers of civilian deaths, which participants fear can be used by al-Shabaab to recruit and radicalise more Somalis. The study also shows that most Somalis resent the presence of the African Union Mission in Somalia because Kenya and Ethiopia are seen as 10 pursuing national interests that are not invested in Somali peace and stability. The study concludes that US extra-judicial killings have failed to constrain the actions of al-Shabaab. Somalis expressed that the leadership of current president, Mohamed Abdullahi Mohamed Farmaajo, holds the unique possibilities of creating national unity that rises above clan divisions and the radical Jihadist ideology of al-Shabaab.
- Full Text:
- Date Issued: 2019
Biochemical characterization of the β-mannanase activity of Bacillus paralicheniformis SVD1
- Authors: Clarke, Matthew David
- Date: 2019
- Subjects: Mycobacterium avium paratuberculosis , Enzymes -- Biotechnology , Lignocellulose -- Biotechnology
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/67570 , vital:29112
- Description: Products produced via the enzymatic hydrolysis of lignocellulosic biomass, the most abundant renewable terrestrial source of carbon, can potentially replace a lot of the fuels and chemicals currently produced using non-renewable hydrocarbons. Mannan is a polysaccharide component of lignocellulose that is abundant in softwoods and legume seeds. Enzymatic hydrolysis of mannan by β-mannanases has various industrial applications, including use in biofuel and prebiotic mannooligosaccharide (MOS) production for the improvement of human and animal health. The industrial use of β-mannanases depends on their biochemical characteristics, such as their activity, stability and substrate specificity. Knowledge of their synergistic interactions with other enzymes is also useful for effective hydrolysis. Bacillus paralicheniformis SVD1 was used as a source for β-mannanases. The two mannanases of B. paralicheniformis SVD1 have not been biochemically characterized apart from minor characterization of crude β-mannanase activity. The protein sequences of the two β-mannanases, of glycosyl hydrolase family 5 and 26, have a 95% - 96% identity to the β-mannanases of B. licheniformis DSM13T (=ATCC14580T). These small protein sequence differences could lead to quite different biochemical characteristics. These mannanases were characterized as these enzymes may have industrially useful characteristics. To induce mannanase production, B. paralicheniformis SVD1 was cultured in broth containing the mannan substrate locust bean gum. Various growth curve parameters were measured over 72 h. Mannanase activity was the highest after 48 h of growth - this was the time at which mannanase activity was concentrated, using 3 kDa centrifugal filtration devices, for biochemical characterization of the crude activity. Zymography revealed that the crude concentrated mannanase fraction consisted of at least two mannanases with relative molecular weights (MWs) of 29.6 kDa and 33 kDa. This was smaller than expected – based on their theoretical molecular masses. Protease activity, which was detected in the broth, was probably the reason. There were two pH optima, pH 5.0 and pH 7.0, which also indicated the presence of two mannanases. The concentrated mannanase displayed characteristics that were expected of a B. paralicheniformis β-mannanase. The temperature optimum was 50°C and the activity loss was less than 7% at 50°C after 24 h. Substrate specificity assays revealed that there was predominantly mannanase activity present. Thin layer chromatography (TLC) analysis of mannan and MOS hydrolysis showed that mainly M2 and M3 MOS were produced; only MOS with a degree of polymerization of 4 or higher were hydrolyzed. Hydrolysis was minimal on mannoligosaccharides with galactose substituents. Activity and MOS production was the highest on soluble, low branched mannan substrates. The highest activity observed was on konjac glucomannan. Purification of the mannanase activity was then attempted using various methods. Ammonium sulfate precipitation, acetone precipitation, as well as centrifugal filtration device concentration was assessed for concentration of the mannanase activity.Concentration was not very successful due to low activity yields (≤ 20%). Anion exchange chromatography (AEC) and size exclusion chromatography (SEC) was used for purification. AEC gave good activity yield and fold purification, but SDS-PAGE analysis revealed the presence of many different proteins so further purification was necessary. SDS-PAGE analysis showed that there were only a few protein contaminants in the SEC fraction. However, the yield was too low to allow for biochemical characterization. The optimized purification procedure, which partially purified the mannanase activity, used 85% ammonium sulfate precipitation, followed by AEC. The fold purification was high (88.9) and the specific activity was 29.5 U.mg-1. A zymogram of the partially purified mannanase showed a mannanase active band with a MW of 40 - 41 kDa. A serine protease inhibitor, phenylmethylsulfonyl fluoride (PMSF), was added during the purification steps. This indicated that the mannanase/s in the crude concentrate, without PMSF added, was hydrolyzed by serine protease activity. Native PAGE zymograms suggested that at least two different isoforms of mannanases were present. Additional purification would be required to determine the true characteristics of the mannanase/s. The biochemical characteristics of the crude and partially purified mannanases were similar. The pH optima of the partially purified mannanases were different; the pH optima were 6.0 and 9.0. The substrate specificities were similar, except that the partially purified mannanases displayed no cellulase and β-D-galactosidase activity, but showed a small amount of α-L-arabinase activity. The partially purified mannanase and a Cyamopsis tetragonolobus GH27 α-galactosidase synergistically hydrolyzed locust bean gum. The M50G50 combination displayed the highest extent of hydrolysis; after 24 h there was a 1.39 fold increase in reducing sugar release and the degree of synergy (DS) was 4.64. TLC analysis indicated that synergy increased the release of small MOS. These MOS could be useful as prebiotics. The synergy between the partially purified mannanase and the commercial cellulase mixture Cellic® CTec2 (Novozymes) on spent coffee grounds (SCG) was also determined. SCG is an abundant industrial waste product that has high mannan content. The SCG was pretreated using NaOH, and the monosaccharide, soluble phenolics and insoluble contents were determined. Glucose and mannose were the dominant monosaccharides in the SCG; the pretreated SCG contained 20.4% (w/w) glucose and 18.5% (w/w) mannose, respectively. The NaOH pretreatment improved mannanase hydrolysis of SCG. It resulted in the opening up and swelling of the SCG particles and removed some of the insoluble solids. The partially purified B. paralicheniformis SVD1 mannanase displayed no detectable activity on SCG, but showed synergy with CTec2, in terms of DS, on untreated and NaOH pretreated SCG. This is the first report of mannanasecellulase synergy on SCG; other studies found that increased hydrolysis was due to additive effects. The results obtained in this study are only an initial assessment of the biochemical properties of B. paralicheniformis SVD1 mannanase activity and its synergy with other enzymes. These results can be used to inform future studies.
- Full Text:
- Date Issued: 2019
- Authors: Clarke, Matthew David
- Date: 2019
- Subjects: Mycobacterium avium paratuberculosis , Enzymes -- Biotechnology , Lignocellulose -- Biotechnology
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/67570 , vital:29112
- Description: Products produced via the enzymatic hydrolysis of lignocellulosic biomass, the most abundant renewable terrestrial source of carbon, can potentially replace a lot of the fuels and chemicals currently produced using non-renewable hydrocarbons. Mannan is a polysaccharide component of lignocellulose that is abundant in softwoods and legume seeds. Enzymatic hydrolysis of mannan by β-mannanases has various industrial applications, including use in biofuel and prebiotic mannooligosaccharide (MOS) production for the improvement of human and animal health. The industrial use of β-mannanases depends on their biochemical characteristics, such as their activity, stability and substrate specificity. Knowledge of their synergistic interactions with other enzymes is also useful for effective hydrolysis. Bacillus paralicheniformis SVD1 was used as a source for β-mannanases. The two mannanases of B. paralicheniformis SVD1 have not been biochemically characterized apart from minor characterization of crude β-mannanase activity. The protein sequences of the two β-mannanases, of glycosyl hydrolase family 5 and 26, have a 95% - 96% identity to the β-mannanases of B. licheniformis DSM13T (=ATCC14580T). These small protein sequence differences could lead to quite different biochemical characteristics. These mannanases were characterized as these enzymes may have industrially useful characteristics. To induce mannanase production, B. paralicheniformis SVD1 was cultured in broth containing the mannan substrate locust bean gum. Various growth curve parameters were measured over 72 h. Mannanase activity was the highest after 48 h of growth - this was the time at which mannanase activity was concentrated, using 3 kDa centrifugal filtration devices, for biochemical characterization of the crude activity. Zymography revealed that the crude concentrated mannanase fraction consisted of at least two mannanases with relative molecular weights (MWs) of 29.6 kDa and 33 kDa. This was smaller than expected – based on their theoretical molecular masses. Protease activity, which was detected in the broth, was probably the reason. There were two pH optima, pH 5.0 and pH 7.0, which also indicated the presence of two mannanases. The concentrated mannanase displayed characteristics that were expected of a B. paralicheniformis β-mannanase. The temperature optimum was 50°C and the activity loss was less than 7% at 50°C after 24 h. Substrate specificity assays revealed that there was predominantly mannanase activity present. Thin layer chromatography (TLC) analysis of mannan and MOS hydrolysis showed that mainly M2 and M3 MOS were produced; only MOS with a degree of polymerization of 4 or higher were hydrolyzed. Hydrolysis was minimal on mannoligosaccharides with galactose substituents. Activity and MOS production was the highest on soluble, low branched mannan substrates. The highest activity observed was on konjac glucomannan. Purification of the mannanase activity was then attempted using various methods. Ammonium sulfate precipitation, acetone precipitation, as well as centrifugal filtration device concentration was assessed for concentration of the mannanase activity.Concentration was not very successful due to low activity yields (≤ 20%). Anion exchange chromatography (AEC) and size exclusion chromatography (SEC) was used for purification. AEC gave good activity yield and fold purification, but SDS-PAGE analysis revealed the presence of many different proteins so further purification was necessary. SDS-PAGE analysis showed that there were only a few protein contaminants in the SEC fraction. However, the yield was too low to allow for biochemical characterization. The optimized purification procedure, which partially purified the mannanase activity, used 85% ammonium sulfate precipitation, followed by AEC. The fold purification was high (88.9) and the specific activity was 29.5 U.mg-1. A zymogram of the partially purified mannanase showed a mannanase active band with a MW of 40 - 41 kDa. A serine protease inhibitor, phenylmethylsulfonyl fluoride (PMSF), was added during the purification steps. This indicated that the mannanase/s in the crude concentrate, without PMSF added, was hydrolyzed by serine protease activity. Native PAGE zymograms suggested that at least two different isoforms of mannanases were present. Additional purification would be required to determine the true characteristics of the mannanase/s. The biochemical characteristics of the crude and partially purified mannanases were similar. The pH optima of the partially purified mannanases were different; the pH optima were 6.0 and 9.0. The substrate specificities were similar, except that the partially purified mannanases displayed no cellulase and β-D-galactosidase activity, but showed a small amount of α-L-arabinase activity. The partially purified mannanase and a Cyamopsis tetragonolobus GH27 α-galactosidase synergistically hydrolyzed locust bean gum. The M50G50 combination displayed the highest extent of hydrolysis; after 24 h there was a 1.39 fold increase in reducing sugar release and the degree of synergy (DS) was 4.64. TLC analysis indicated that synergy increased the release of small MOS. These MOS could be useful as prebiotics. The synergy between the partially purified mannanase and the commercial cellulase mixture Cellic® CTec2 (Novozymes) on spent coffee grounds (SCG) was also determined. SCG is an abundant industrial waste product that has high mannan content. The SCG was pretreated using NaOH, and the monosaccharide, soluble phenolics and insoluble contents were determined. Glucose and mannose were the dominant monosaccharides in the SCG; the pretreated SCG contained 20.4% (w/w) glucose and 18.5% (w/w) mannose, respectively. The NaOH pretreatment improved mannanase hydrolysis of SCG. It resulted in the opening up and swelling of the SCG particles and removed some of the insoluble solids. The partially purified B. paralicheniformis SVD1 mannanase displayed no detectable activity on SCG, but showed synergy with CTec2, in terms of DS, on untreated and NaOH pretreated SCG. This is the first report of mannanasecellulase synergy on SCG; other studies found that increased hydrolysis was due to additive effects. The results obtained in this study are only an initial assessment of the biochemical properties of B. paralicheniformis SVD1 mannanase activity and its synergy with other enzymes. These results can be used to inform future studies.
- Full Text:
- Date Issued: 2019
Biological properties and interactions of Kalaharituber pfeilii
- Authors: Krele, Viwe
- Date: 2019
- Subjects: Kalaharituber pfeilii , Pezizales -- South Africa , Desert plants -- South Africa , Truffle culture -- South Africa , Plant biochemical genetics , Enzymes -- Analysis
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/72257 , vital:30022
- Description: Dessert truffles are seasonal macro fungi and have been identified in several parts of the world including South Africa. The first part of the present study dealt with the assessment of the biologically active compounds of the Kalahari truffles found in the Northern Cape of South Africa. Truffles extracts (methanol, ethanol, aqueous) were investigated for their antimicrobial properties towards Gram-positive and Gram-negative bacteria. The results demonstrated that the truffle extracts tested had no inhibitory effects against the bacterial isolates. The truffle mycelial growth was also noted to be ineffective against the selected bacteria. The bacteria tested in the present study showed some antagonistic effects against the fungus. Cultures of K. pfeilii were also screened for enzyme production including amylase, protease, cellulose, and laccase. Evaluation of the potential of K. pfeilii mycelia to produce these industrially and economically important enzymes demonstrated both amylase and protease activity. However, for laccase and cellulose, no activity was detected. The second part of the present study aimed at optimizing biomass production by K. pfeilii in liquid culture media. FF Microplate containing 95 discreet carbon sources were employed to test for substrate utilization. Blanked readings above 0.1 were regarded as positive for utilization, and 4 substrates were selected as potential substrates and were included in liquid media. Media was evaluated for mycelial biomass production. Of the carbon sources tested sucrose proved to be the most suitable for supporting mycelial growth. The third part of the current study included investigating the diversity of microbial communities colonizing the rhizosheath of Stipagrostis ciliata var. capensis (the host plant of K. pfeilii) and these were identified by means of next-generation sequencing using Illumina Miseq. Bioinformatics tools were utilized in analyzing the data. Actinobacteria were found to be the most dominant bacterial phylum, followed by unclassified bacteria, Proteobacteria, and Acidobacteria. The top 25 sequences were selected and clustered into bacterial OTUs (at 97% threshold) which were assigned into 1 phylum (Actinobacteria), 1 family (Geodermatophilaceae) and 23 genera. This phylum is well known for its secondary metabolites. Streptomyces sp. was the most frequently encountered genus. The results from this study necessitate further investigations with regards to the function and evolution of fungal-bacterial associations. Wheather these bacteria have a contribution towards the truffle development, it is still not confirmed.
- Full Text:
- Date Issued: 2019
- Authors: Krele, Viwe
- Date: 2019
- Subjects: Kalaharituber pfeilii , Pezizales -- South Africa , Desert plants -- South Africa , Truffle culture -- South Africa , Plant biochemical genetics , Enzymes -- Analysis
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/72257 , vital:30022
- Description: Dessert truffles are seasonal macro fungi and have been identified in several parts of the world including South Africa. The first part of the present study dealt with the assessment of the biologically active compounds of the Kalahari truffles found in the Northern Cape of South Africa. Truffles extracts (methanol, ethanol, aqueous) were investigated for their antimicrobial properties towards Gram-positive and Gram-negative bacteria. The results demonstrated that the truffle extracts tested had no inhibitory effects against the bacterial isolates. The truffle mycelial growth was also noted to be ineffective against the selected bacteria. The bacteria tested in the present study showed some antagonistic effects against the fungus. Cultures of K. pfeilii were also screened for enzyme production including amylase, protease, cellulose, and laccase. Evaluation of the potential of K. pfeilii mycelia to produce these industrially and economically important enzymes demonstrated both amylase and protease activity. However, for laccase and cellulose, no activity was detected. The second part of the present study aimed at optimizing biomass production by K. pfeilii in liquid culture media. FF Microplate containing 95 discreet carbon sources were employed to test for substrate utilization. Blanked readings above 0.1 were regarded as positive for utilization, and 4 substrates were selected as potential substrates and were included in liquid media. Media was evaluated for mycelial biomass production. Of the carbon sources tested sucrose proved to be the most suitable for supporting mycelial growth. The third part of the current study included investigating the diversity of microbial communities colonizing the rhizosheath of Stipagrostis ciliata var. capensis (the host plant of K. pfeilii) and these were identified by means of next-generation sequencing using Illumina Miseq. Bioinformatics tools were utilized in analyzing the data. Actinobacteria were found to be the most dominant bacterial phylum, followed by unclassified bacteria, Proteobacteria, and Acidobacteria. The top 25 sequences were selected and clustered into bacterial OTUs (at 97% threshold) which were assigned into 1 phylum (Actinobacteria), 1 family (Geodermatophilaceae) and 23 genera. This phylum is well known for its secondary metabolites. Streptomyces sp. was the most frequently encountered genus. The results from this study necessitate further investigations with regards to the function and evolution of fungal-bacterial associations. Wheather these bacteria have a contribution towards the truffle development, it is still not confirmed.
- Full Text:
- Date Issued: 2019
Black forest
- Authors: Sachikonye, Tsitsi S A
- Date: 2019
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/92759 , vital:30745
- Full Text:
- Date Issued: 2019
- Authors: Sachikonye, Tsitsi S A
- Date: 2019
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/92759 , vital:30745
- Full Text:
- Date Issued: 2019
BODIPY and porphyrin dyes for direct glucose sensing and optical limiting applications
- Authors: Ndebele, Nobuhle
- Date: 2019
- Subjects: Boron compounds , Boric acid , Porphyrins , Dyes and dying -- Chemistry
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/97221 , vital:31412
- Description: A series of BODIPY dyes functionalised with boronic acid in the 3,5-positions were successfully synthesised and characterised by using various analytical techniques. The dyes were prepared through a slight modification of the conventional acid catalysed condensation method. Phenylboronic acid moieties were added as styryl groups at the 3,5-positions of the 1,3,5,7-tetrametylBODIPY cores using a modified Knoevengal condensation method. The addition of the styryls resulted in the main absorption band of the dyes red-shifting to the 630−650 nm region. The photophysical and electrochemical properties of these dyes were studied to determine whether the dyes are suitable for use in the fluorescent, colourimetric and electrochemical detection of glucose. Boronic acid moieties were added as bioreceptor recognition elements because they have an affinity for carbohydrates and therefore would be able to bind and “detect” glucose. The series of BODIPY dyes did not show a “turn-on” fluorescence effect upon addition with glucose at the physiological pH. This was attributed on the basis of molecular modelling to the absence of an MO localised on the boronic-acid-substituted styryl moieties that lie close in energy to the HOMO and LUMO that facilitates the formation of an intramolecular charge transfer state. However, colourimetric changes that are visible to the naked eye are observed at basic pH when glucose was added to the dye solutions. The dyes exhibited favourable electrochemical behaviour and were able to detect glucose directly in this context when glassy carbon electrodes are modified through the drop dry method. A series of Sn(IV) porphyrins with thienyl and phenyl groups at the meso-positions were successfully synthesised and characterised. Pyridine and tetrabutyl axial ligands were added to the porphyrins to limit aggregation. The optical limiting properties of these porphyrins and three styrylated BODIPY dyes were studied in benzene and dichloromethane. Dyes were also embedded in polystyrene and studied as thin films to further gauge their suitability for use in optical limiting applications. Second-order hyperpolarizability, third-order susceptibly, non-linear absorption with reversible saturable absorption and the optical limiting threshold, were the parameters studied. Three of the four porphyrins and the three styrylated BODIPY dyes showed favourable optical limiting behaviour, which was further enhanced when the dyes are embedded in polymer thin films.
- Full Text:
- Date Issued: 2019
- Authors: Ndebele, Nobuhle
- Date: 2019
- Subjects: Boron compounds , Boric acid , Porphyrins , Dyes and dying -- Chemistry
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/97221 , vital:31412
- Description: A series of BODIPY dyes functionalised with boronic acid in the 3,5-positions were successfully synthesised and characterised by using various analytical techniques. The dyes were prepared through a slight modification of the conventional acid catalysed condensation method. Phenylboronic acid moieties were added as styryl groups at the 3,5-positions of the 1,3,5,7-tetrametylBODIPY cores using a modified Knoevengal condensation method. The addition of the styryls resulted in the main absorption band of the dyes red-shifting to the 630−650 nm region. The photophysical and electrochemical properties of these dyes were studied to determine whether the dyes are suitable for use in the fluorescent, colourimetric and electrochemical detection of glucose. Boronic acid moieties were added as bioreceptor recognition elements because they have an affinity for carbohydrates and therefore would be able to bind and “detect” glucose. The series of BODIPY dyes did not show a “turn-on” fluorescence effect upon addition with glucose at the physiological pH. This was attributed on the basis of molecular modelling to the absence of an MO localised on the boronic-acid-substituted styryl moieties that lie close in energy to the HOMO and LUMO that facilitates the formation of an intramolecular charge transfer state. However, colourimetric changes that are visible to the naked eye are observed at basic pH when glucose was added to the dye solutions. The dyes exhibited favourable electrochemical behaviour and were able to detect glucose directly in this context when glassy carbon electrodes are modified through the drop dry method. A series of Sn(IV) porphyrins with thienyl and phenyl groups at the meso-positions were successfully synthesised and characterised. Pyridine and tetrabutyl axial ligands were added to the porphyrins to limit aggregation. The optical limiting properties of these porphyrins and three styrylated BODIPY dyes were studied in benzene and dichloromethane. Dyes were also embedded in polystyrene and studied as thin films to further gauge their suitability for use in optical limiting applications. Second-order hyperpolarizability, third-order susceptibly, non-linear absorption with reversible saturable absorption and the optical limiting threshold, were the parameters studied. Three of the four porphyrins and the three styrylated BODIPY dyes showed favourable optical limiting behaviour, which was further enhanced when the dyes are embedded in polymer thin films.
- Full Text:
- Date Issued: 2019
Careerism and capitalism as women’s emancipation: a critical analysis of Rand Merchant Bank’s ‘Athena Programme', South Africa
- Authors: Mosesi, Poloko Prudence
- Date: 2019
- Subjects: Rand Merchant Bank (South Africa) , Women in economic development -- South Africa , Women in finance -- South Africa , Neoliberalism -- South Africa
- Language: English
- Type: text , Thesis , Masters , MSocSc
- Identifier: http://hdl.handle.net/10962/140344 , vital:37881
- Description: Against the backdrop of debates on feminism and neo– liberalism, this thesis presents a critical analysis of Rand Merchant Bank’s (RMB) Athena programme in South Africa – an award– winning programme run by women, which aims to develop women as senior managers – and of the type of feminism it represents, using a Marxist feminist theoretical framework. Rand Merchant Bank’s is one of the largest investment banks in Africa, part of the giant First Rand Group (FRG) alongside First National Bank (FNB) group. The thesis, based on a detailed case study using qualitative methods, argues that Athena is a very much product of its time: it advances the argument that if more women were in position of power, women in general would be free, and it views the problem of women’s oppression with an individualist lens, which focuses on attitudes and confidence. Athena, like many initiatives of the neo– liberal era, such as Sandberg’s Lean– In philosophy and the Nike Foundation’s ‘Girl Effect’ promote individual understanding and emancipation of women, which sees emancipation in terms of creating a neo– liberal subject that operates more effectively within a capitalist framework, sees capitalism as the solution – rather than the cause – of women’s unequal circumstance and ignores structural issues like class. In effect, Athena argues that the free market and big corporations are neutral tools that can answer the question of women equality, if only women had the correct attitudes, and so long as corporate hierarchies and profits are accepted as fair, and women are seen as an untapped resource that can be used in a ‘smart economics.’ What all these initiatives have in common is shifting the burden and responsibility to women without proper interrogation of the systems that perpetuate inequalities, and a trickle– down theory, according to which more women capitalists and more women in the ruling class will empower the women in the working class.
- Full Text:
- Date Issued: 2019
- Authors: Mosesi, Poloko Prudence
- Date: 2019
- Subjects: Rand Merchant Bank (South Africa) , Women in economic development -- South Africa , Women in finance -- South Africa , Neoliberalism -- South Africa
- Language: English
- Type: text , Thesis , Masters , MSocSc
- Identifier: http://hdl.handle.net/10962/140344 , vital:37881
- Description: Against the backdrop of debates on feminism and neo– liberalism, this thesis presents a critical analysis of Rand Merchant Bank’s (RMB) Athena programme in South Africa – an award– winning programme run by women, which aims to develop women as senior managers – and of the type of feminism it represents, using a Marxist feminist theoretical framework. Rand Merchant Bank’s is one of the largest investment banks in Africa, part of the giant First Rand Group (FRG) alongside First National Bank (FNB) group. The thesis, based on a detailed case study using qualitative methods, argues that Athena is a very much product of its time: it advances the argument that if more women were in position of power, women in general would be free, and it views the problem of women’s oppression with an individualist lens, which focuses on attitudes and confidence. Athena, like many initiatives of the neo– liberal era, such as Sandberg’s Lean– In philosophy and the Nike Foundation’s ‘Girl Effect’ promote individual understanding and emancipation of women, which sees emancipation in terms of creating a neo– liberal subject that operates more effectively within a capitalist framework, sees capitalism as the solution – rather than the cause – of women’s unequal circumstance and ignores structural issues like class. In effect, Athena argues that the free market and big corporations are neutral tools that can answer the question of women equality, if only women had the correct attitudes, and so long as corporate hierarchies and profits are accepted as fair, and women are seen as an untapped resource that can be used in a ‘smart economics.’ What all these initiatives have in common is shifting the burden and responsibility to women without proper interrogation of the systems that perpetuate inequalities, and a trickle– down theory, according to which more women capitalists and more women in the ruling class will empower the women in the working class.
- Full Text:
- Date Issued: 2019
Categorising Network Telescope data using big data enrichment techniques
- Authors: Davis, Michael Reginald
- Date: 2019
- Subjects: Denial of service attacks , Big data , Computer networks -- Security measures
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/92941 , vital:30766
- Description: Network Telescopes, Internet backbone sampling, IDS and other forms of network-sourced Threat Intelligence provide researchers with insight into the methods and intent of remote entities by capturing network traffic and analysing the resulting data. This analysis and determination of intent is made difficult by the large amounts of potentially malicious traffic, coupled with limited amount of knowledge that can be attributed to the source of the incoming data, as the source is known only by its IP address. Due to the lack of commonly available tooling, many researchers start this analysis from the beginning and so repeat and re-iterate previous research as the bulk of their work. As a result new insight into methods and approaches of analysis is gained at a high cost. Our research approaches this problem by using additional knowledge about the source IP address such as open ports, reverse and forward DNS, BGP routing tables and more, to enhance the researcher's ability to understand the traffic source. The research is a BigData experiment, where large (hundreds of GB) datasets are merged with a two month section of Network Telescope data using a set of Python scripts. The result are written to a Google BigQuery database table. Analysis of the network data is greatly simplified, with questions about the nature of the source, such as its device class (home routing device or server), potential vulnerabilities (open telnet ports or databases) and location becoming relatively easy to answer. Using this approach, researchers can focus on the questions that need answering and efficiently address them. This research could be taken further by using additional data sources such as Geo-location, WHOIS lookups, Threat Intelligence feeds and many others. Other potential areas of research include real-time categorisation of incoming packets, in order to better inform alerting and reporting systems' configuration. In conclusion, categorising Network Telescope data in this way provides insight into the intent of the (apparent) originator and as such is a valuable tool for those seeking to understand the purpose and intent of arriving packets. In particular, the ability to remove packets categorised as non-malicious (e.g. those in the Research category) from the data eliminates a known source of `noise' from the data. This allows the researcher to focus their efforts in a more productive manner.
- Full Text:
- Date Issued: 2019
- Authors: Davis, Michael Reginald
- Date: 2019
- Subjects: Denial of service attacks , Big data , Computer networks -- Security measures
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/92941 , vital:30766
- Description: Network Telescopes, Internet backbone sampling, IDS and other forms of network-sourced Threat Intelligence provide researchers with insight into the methods and intent of remote entities by capturing network traffic and analysing the resulting data. This analysis and determination of intent is made difficult by the large amounts of potentially malicious traffic, coupled with limited amount of knowledge that can be attributed to the source of the incoming data, as the source is known only by its IP address. Due to the lack of commonly available tooling, many researchers start this analysis from the beginning and so repeat and re-iterate previous research as the bulk of their work. As a result new insight into methods and approaches of analysis is gained at a high cost. Our research approaches this problem by using additional knowledge about the source IP address such as open ports, reverse and forward DNS, BGP routing tables and more, to enhance the researcher's ability to understand the traffic source. The research is a BigData experiment, where large (hundreds of GB) datasets are merged with a two month section of Network Telescope data using a set of Python scripts. The result are written to a Google BigQuery database table. Analysis of the network data is greatly simplified, with questions about the nature of the source, such as its device class (home routing device or server), potential vulnerabilities (open telnet ports or databases) and location becoming relatively easy to answer. Using this approach, researchers can focus on the questions that need answering and efficiently address them. This research could be taken further by using additional data sources such as Geo-location, WHOIS lookups, Threat Intelligence feeds and many others. Other potential areas of research include real-time categorisation of incoming packets, in order to better inform alerting and reporting systems' configuration. In conclusion, categorising Network Telescope data in this way provides insight into the intent of the (apparent) originator and as such is a valuable tool for those seeking to understand the purpose and intent of arriving packets. In particular, the ability to remove packets categorised as non-malicious (e.g. those in the Research category) from the data eliminates a known source of `noise' from the data. This allows the researcher to focus their efforts in a more productive manner.
- Full Text:
- Date Issued: 2019
Changes and continuities over time in the cultural significance of the Nyaminyami water spirit among the BaTonga people of northwestern Zimbabwe
- Authors: Matanzima, Joshua
- Date: 2019
- Subjects: Water spirits -- Zimbabwe , Tsonga (African people) -- Zimbabwe , Tsonga (African people) -- Zimbabwe -- Religion , Tsonga (African people) -- Zimbabwe -- Rites and ceremonies , Tsonga (African people) -- Zimbabwe -- Social life and customs , Mythology, Tsonga , Mythology, Zimbabwean , Nyaminyami (Spirit)
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/94189 , vital:31015
- Description: Research attests that beliefs in water spirits are an integral part of cultures of many indigenous communities across the globe. These water spirits play significant political, religious and socio-economic roles for the people concerned. However, the functions of water spirits are not constant, but change over time, especially when the people believing in water spirits undergo drastic socio- economic processes of change. It is in this context that this thesis traces the cultural significance over time, of the Nyaminyami water spirit, among some BaTonga people, living in the immediate vicinity of the Kariba gorge area, in north-western Zimbabwe. While previous studies document the existence of beliefs in Nyaminyami, none of these has systematically traced the historical significance of Nyaminyami, in terms of changes and continuities over time. Thus, this thesis makes a valuable contribution to knowledge with regards to the history and religion of the BaTonga people. The thesis argues that Nyaminyami‘s cultural significance or functions evolved over time, due to numerous socio- economic and political processes of change. The major changes that significantly influenced the practices relating to Nyaminyami include colonialism, Kariba dam construction and resettlement, the migration after resettlement in the 1960s and 1970s, the independence of Zimbabwe, and the alienation of the Kariba waterscape from the BaTonga. To be able to arrive at specific findings and conclusions, the thesis is underpinned by theories about resettlement, approaches to water divinities, and theories of religion and social change. The thesis has five ethnographic chapters that focus on specific time periods, illustrating the major socio- economic changes of each epoch, and showing how these changes impacted upon practices and beliefs relating to Nyaminyami. The thesis also documents how Nyaminyami beliefs are variedly distributed along different social variables that include gender, age, income and geographical location. In order to achieve the findings presented, the thesis utilized ethnographic evidence obtained from semi- structured interviews, participant observation, anthropology of extraordinary experience, document review and archival research.
- Full Text:
- Date Issued: 2019
- Authors: Matanzima, Joshua
- Date: 2019
- Subjects: Water spirits -- Zimbabwe , Tsonga (African people) -- Zimbabwe , Tsonga (African people) -- Zimbabwe -- Religion , Tsonga (African people) -- Zimbabwe -- Rites and ceremonies , Tsonga (African people) -- Zimbabwe -- Social life and customs , Mythology, Tsonga , Mythology, Zimbabwean , Nyaminyami (Spirit)
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/94189 , vital:31015
- Description: Research attests that beliefs in water spirits are an integral part of cultures of many indigenous communities across the globe. These water spirits play significant political, religious and socio-economic roles for the people concerned. However, the functions of water spirits are not constant, but change over time, especially when the people believing in water spirits undergo drastic socio- economic processes of change. It is in this context that this thesis traces the cultural significance over time, of the Nyaminyami water spirit, among some BaTonga people, living in the immediate vicinity of the Kariba gorge area, in north-western Zimbabwe. While previous studies document the existence of beliefs in Nyaminyami, none of these has systematically traced the historical significance of Nyaminyami, in terms of changes and continuities over time. Thus, this thesis makes a valuable contribution to knowledge with regards to the history and religion of the BaTonga people. The thesis argues that Nyaminyami‘s cultural significance or functions evolved over time, due to numerous socio- economic and political processes of change. The major changes that significantly influenced the practices relating to Nyaminyami include colonialism, Kariba dam construction and resettlement, the migration after resettlement in the 1960s and 1970s, the independence of Zimbabwe, and the alienation of the Kariba waterscape from the BaTonga. To be able to arrive at specific findings and conclusions, the thesis is underpinned by theories about resettlement, approaches to water divinities, and theories of religion and social change. The thesis has five ethnographic chapters that focus on specific time periods, illustrating the major socio- economic changes of each epoch, and showing how these changes impacted upon practices and beliefs relating to Nyaminyami. The thesis also documents how Nyaminyami beliefs are variedly distributed along different social variables that include gender, age, income and geographical location. In order to achieve the findings presented, the thesis utilized ethnographic evidence obtained from semi- structured interviews, participant observation, anthropology of extraordinary experience, document review and archival research.
- Full Text:
- Date Issued: 2019
Chitin hydrolysis with chitinolytic enzymes for the production of chitooligomers with antimicrobial properties
- Authors: Oree, Glynis
- Date: 2019
- Subjects: Chitin -- Biotechnology , Enzymes -- Biotechnology , Hydrolysis , Chitooligomers -- Biotechnology
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/67887 , vital:29165
- Description: There are many diseases and illnesses in the world that require new drug treatments and chitin has been shown to produce chitooligomeric derivatives which exhibit promising antimicrobial and immune-enhancing properties. However, the rate-limiting step is associated with the high recalcitrance of chitinous substrates, and low hydrolytic activities of chitinolytic enzymes, resulting in low product release. To improve and create a more sustainable and economical process, enhancing chitin hydrolysis through various treatment procedures is essential for obtaining high enzyme hydrolysis rates, resulting in a higher yield of chitooligomers (CHOS). In literature, pre-treatment of insoluble biomass is generally associated with an increase in accessibility of the carbohydrate to hydrolytic enzymes, thus generating more products. The first part of this study investigated the effect of alkali- (NaOH) and acid pre-treatments (HCl and phosphoric acid) on chitin biomass, and chemical and morphological modifications were assessed by the employment of scanning electron microscopy (SEM), Fourier Transform Infrared Spectroscopy (FTIR), Energy-Dispersive X-ray spectrometery (EDX) and x-ray diffraction (XRD). Data obtained confirmed that pre-treated substrates were more chemically and morphologically modified. These results confirmed the fact that pre-treatment of chitin disrupts the structure of the biomass, rendering the polymer more accessible for enzymatic hydrolysis. The commercial chitinases from Bacillus cereus and Streptomyces griseus (CHB and CHS) are costly. Bio-prospecting for other chitin-degrading enzymes from alternate sources such as Oidiodendron maius, or the recombinant expression of CHOS, was a more economically feasible avenue. The chit1 gene from Thermomyces lanuginosus, expressed in Pichia pastoris, produced a large range CHOS with a degree of polymerisation (DP) ranging from 1 to above 6. TLC analysis showed that O. maius exhibited chitin-degrading properties by producing CHOS with a DP length of 1 to 3. These two sources were therefore successful in producing chitin-degrading enzymes. The physico-chemical properties of commercial (CHB and CHS) and expressed (Chit1) chitinolytic enzymes were investigated, to determine under which biochemical conditions and on which type of biomass they can function on optimally, for the production of value-added products such as CHOS. Substrate affinity assays were conducted on the un-treated and pre-treated biomass. TLC revealed that chitosan hydrolysis by the commercial chitinases produced the largest range of CHOS with a DP length ranging from 1 to 6. A range of temperatures (35-90oC) were investigated and CHB, CHS and Chit1 displayed optimum activities at 50, 40 and 45 oC, respectively. Thermostability studies that were conducted at 37 and 50oC revealed that CHB and CHS were most stable at 37oC. Chit1 showed great thermostablity at both temperatures, rendering this enzyme suitable for industrial processes at high temperatures. pH optima studies demonstrated that the pH optima for CHB, CHS and Chit1 was at a pH of 5.0, with specific activities of 33.459, 46.2 and 5.776 μmol/h/mg, respectively. The chain cleaving patterns of the commercial enzymes were determined and exo-chitinase activity was exhibited, due to the production of CHOS that were predominantly of a DP length of 2. Enzyme binary synergy studies were conducted with commercial chitinases (CHB and CHS) on colloidal chitin. Studies illustrated that the simultaneous combination of CHB 75%: CHS 25% produced the highest specific activity (3.526 μmol/h/mg), with no synergy. TLC analysis of this enzyme combination over time revealed that predominantly chitobiose was produced. This suggested that the substrate crystallinity and morphology played an important role in the way the enzymes cleaved the carbohydrate. Since CHOS have shown great promise for their antimicrobial properties, the CHOS generated from the chitinous substrates were tested for antimicrobial properties on Bacillus subtilis, Escherichia coli, Klebsiella and Staphlococcus aureus. This study revealed that certain CHOS produced have inhibitory effects on certain bacteria and could potentially be used in the pharamceutical or medical industries. In conclusion, this study revealed that chitinases can be produced and found in alternate sources and be used for the hydrolysis of chitinous biomass in a more sustainabe and economically viable manner. The chitinases investigated (CHB, CHS and Chit1) exhibited different cleaving patterns of the chitinous substrates due to the chemical and morphological properties of the biomass. CHOS produced from chitinous biomass exhibited some inhibitory effects on bacterial growth and show potential for use in the medical industry.
- Full Text:
- Date Issued: 2019
- Authors: Oree, Glynis
- Date: 2019
- Subjects: Chitin -- Biotechnology , Enzymes -- Biotechnology , Hydrolysis , Chitooligomers -- Biotechnology
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/67887 , vital:29165
- Description: There are many diseases and illnesses in the world that require new drug treatments and chitin has been shown to produce chitooligomeric derivatives which exhibit promising antimicrobial and immune-enhancing properties. However, the rate-limiting step is associated with the high recalcitrance of chitinous substrates, and low hydrolytic activities of chitinolytic enzymes, resulting in low product release. To improve and create a more sustainable and economical process, enhancing chitin hydrolysis through various treatment procedures is essential for obtaining high enzyme hydrolysis rates, resulting in a higher yield of chitooligomers (CHOS). In literature, pre-treatment of insoluble biomass is generally associated with an increase in accessibility of the carbohydrate to hydrolytic enzymes, thus generating more products. The first part of this study investigated the effect of alkali- (NaOH) and acid pre-treatments (HCl and phosphoric acid) on chitin biomass, and chemical and morphological modifications were assessed by the employment of scanning electron microscopy (SEM), Fourier Transform Infrared Spectroscopy (FTIR), Energy-Dispersive X-ray spectrometery (EDX) and x-ray diffraction (XRD). Data obtained confirmed that pre-treated substrates were more chemically and morphologically modified. These results confirmed the fact that pre-treatment of chitin disrupts the structure of the biomass, rendering the polymer more accessible for enzymatic hydrolysis. The commercial chitinases from Bacillus cereus and Streptomyces griseus (CHB and CHS) are costly. Bio-prospecting for other chitin-degrading enzymes from alternate sources such as Oidiodendron maius, or the recombinant expression of CHOS, was a more economically feasible avenue. The chit1 gene from Thermomyces lanuginosus, expressed in Pichia pastoris, produced a large range CHOS with a degree of polymerisation (DP) ranging from 1 to above 6. TLC analysis showed that O. maius exhibited chitin-degrading properties by producing CHOS with a DP length of 1 to 3. These two sources were therefore successful in producing chitin-degrading enzymes. The physico-chemical properties of commercial (CHB and CHS) and expressed (Chit1) chitinolytic enzymes were investigated, to determine under which biochemical conditions and on which type of biomass they can function on optimally, for the production of value-added products such as CHOS. Substrate affinity assays were conducted on the un-treated and pre-treated biomass. TLC revealed that chitosan hydrolysis by the commercial chitinases produced the largest range of CHOS with a DP length ranging from 1 to 6. A range of temperatures (35-90oC) were investigated and CHB, CHS and Chit1 displayed optimum activities at 50, 40 and 45 oC, respectively. Thermostability studies that were conducted at 37 and 50oC revealed that CHB and CHS were most stable at 37oC. Chit1 showed great thermostablity at both temperatures, rendering this enzyme suitable for industrial processes at high temperatures. pH optima studies demonstrated that the pH optima for CHB, CHS and Chit1 was at a pH of 5.0, with specific activities of 33.459, 46.2 and 5.776 μmol/h/mg, respectively. The chain cleaving patterns of the commercial enzymes were determined and exo-chitinase activity was exhibited, due to the production of CHOS that were predominantly of a DP length of 2. Enzyme binary synergy studies were conducted with commercial chitinases (CHB and CHS) on colloidal chitin. Studies illustrated that the simultaneous combination of CHB 75%: CHS 25% produced the highest specific activity (3.526 μmol/h/mg), with no synergy. TLC analysis of this enzyme combination over time revealed that predominantly chitobiose was produced. This suggested that the substrate crystallinity and morphology played an important role in the way the enzymes cleaved the carbohydrate. Since CHOS have shown great promise for their antimicrobial properties, the CHOS generated from the chitinous substrates were tested for antimicrobial properties on Bacillus subtilis, Escherichia coli, Klebsiella and Staphlococcus aureus. This study revealed that certain CHOS produced have inhibitory effects on certain bacteria and could potentially be used in the pharamceutical or medical industries. In conclusion, this study revealed that chitinases can be produced and found in alternate sources and be used for the hydrolysis of chitinous biomass in a more sustainabe and economically viable manner. The chitinases investigated (CHB, CHS and Chit1) exhibited different cleaving patterns of the chitinous substrates due to the chemical and morphological properties of the biomass. CHOS produced from chitinous biomass exhibited some inhibitory effects on bacterial growth and show potential for use in the medical industry.
- Full Text:
- Date Issued: 2019
Climatic suitability of Dichrorampha odorata Brown and Zachariades (Lepidoptera: Tortricidae), a shoot-boring moth for the biological control of Chromolaena odorata (L.) R.M. King and H. Robinson (Asteraceae) in South Africa
- Authors: Nqayi, Slindile Brightness
- Date: 2019
- Subjects: CLIMEX , Chromolaena odorata -- Biological control -- South Africa , Tortricidae -- South Africa , Bioclimatology -- Software
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/92208 , vital:30681
- Description: Biological control using natural enemies introduced from the native range is an integral component of the management of Chromolaena odorata, a serious invader in the eastern regions of South Africa. A number of biological control agents for C. odorata have been released in South Africa, and one of them, Dichrorampha odorata, has failed to establish. To understand if D. odorata failed to establish due to climate incompatibility, its thermal physiology was investigated. Thermal tolerance data were used to determine the developmental thresholds and number of generations that D. odorata is capable of going through in South Africa per year. These predictions were generated using CLIMEX temperature data and the degree-day parameters K and t0. Developmental time decreased with increasing temperatures ranging from 20 °C to 30°C, with immature stages not able to complete development at 18°C and 32°C. The developmental threshold, to, was determined as 8.45 °C with 872.4 degree-days required to complete development (K), indicating that D. odorata is capable of producing a maximum number of 6.5 generations per year in South Africa. The CLIMEX data indicated that the east coast regions of South Africa, which are the heaviest invaded areas by C. odorata in South Africa, were climatically most suitable for D. odorata to. D. odorata lower (LLT50) and upper (ULT50) lethal temperatures were -4.5°C and 39.64°C for larvae and 1.83 and 41.02°C for adults, and D. odorata adults were able to maintain locomotory functioning at 4.4 to 43.7°C, respectively. Acclimation at low and high temperatures indicate that when D. odorata was kept at a lower temperature of 20°C for 7 days, it became tolerant to warmer and cooler temperatures (1.95 and 44.41°C) when compared to D. odorata reared at 25°C (3.36 and 43.67°C) and 30°C (5.92 and 42.93°C). Dichrorampha odorata is therefore climatically suitable for release and should establish in South Africa to control C. odorata. The establishment and persistence of D. odorata will not be limited by climatic conditions but rather the distribution of its host weed, C. odorata in South Africa. Also, this study presents a decision-making protocol for the release of D. odorata to allow better performance in the field.
- Full Text:
- Date Issued: 2019
- Authors: Nqayi, Slindile Brightness
- Date: 2019
- Subjects: CLIMEX , Chromolaena odorata -- Biological control -- South Africa , Tortricidae -- South Africa , Bioclimatology -- Software
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/92208 , vital:30681
- Description: Biological control using natural enemies introduced from the native range is an integral component of the management of Chromolaena odorata, a serious invader in the eastern regions of South Africa. A number of biological control agents for C. odorata have been released in South Africa, and one of them, Dichrorampha odorata, has failed to establish. To understand if D. odorata failed to establish due to climate incompatibility, its thermal physiology was investigated. Thermal tolerance data were used to determine the developmental thresholds and number of generations that D. odorata is capable of going through in South Africa per year. These predictions were generated using CLIMEX temperature data and the degree-day parameters K and t0. Developmental time decreased with increasing temperatures ranging from 20 °C to 30°C, with immature stages not able to complete development at 18°C and 32°C. The developmental threshold, to, was determined as 8.45 °C with 872.4 degree-days required to complete development (K), indicating that D. odorata is capable of producing a maximum number of 6.5 generations per year in South Africa. The CLIMEX data indicated that the east coast regions of South Africa, which are the heaviest invaded areas by C. odorata in South Africa, were climatically most suitable for D. odorata to. D. odorata lower (LLT50) and upper (ULT50) lethal temperatures were -4.5°C and 39.64°C for larvae and 1.83 and 41.02°C for adults, and D. odorata adults were able to maintain locomotory functioning at 4.4 to 43.7°C, respectively. Acclimation at low and high temperatures indicate that when D. odorata was kept at a lower temperature of 20°C for 7 days, it became tolerant to warmer and cooler temperatures (1.95 and 44.41°C) when compared to D. odorata reared at 25°C (3.36 and 43.67°C) and 30°C (5.92 and 42.93°C). Dichrorampha odorata is therefore climatically suitable for release and should establish in South Africa to control C. odorata. The establishment and persistence of D. odorata will not be limited by climatic conditions but rather the distribution of its host weed, C. odorata in South Africa. Also, this study presents a decision-making protocol for the release of D. odorata to allow better performance in the field.
- Full Text:
- Date Issued: 2019
Clinical psychologists’ perceptions of the phenomenon of schizophrenia in a psychiatric setting in the Eastern Cape, South Africa
- Authors: Hamman, Colette
- Date: 2019
- Subjects: Schizophrenia -- Diagnosis -- South Africa , Schizophrenia -- Treatment -- South Africa , Schizophrenics -- Rehabilitation -- South Africa , Schizophrenics -- South Africa -- Case studies
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/71398 , vital:29845
- Description: Numerous international and South African scholars are critical of the dominant research on the phenomenon of schizophrenia. Rather than refuting dominant biomedical psychiatric conceptualisations of schizophrenia, there is a call for incorporating a focus on the psychology of the person diagnosed with schizophrenia. In South Africa, the integration of the psychosocial components of psychotic experiences into the understanding and treatment of psychosis are still neglected in biomedically-focused psychiatric settings. In relation to this call, the role of clinical psychologists working within these settings seems pertinent. Against this background, this study aimed to explore and describe the perceptions of clinical psychologists, working in a psychiatric setting in South Africa, in relation to the phenomenon of schizophrenia. Informed by a social constructionist theoretical framework, this study utilised a qualitative research design and a semi-structured interview schedule. In-depth, individual interviews were conducted with three clinical psychologists and the transcribed interviews were analysed using thematic analysis. From the data, perceptions were identified as largely polarised in relation to the phenomenon of schizophrenia. These polarised perceptions included: Physical impact of schizophrenia versus social impact of schizophrenia; rehabilitation of schizophrenia versus recovery within schizophrenia; diagnostic frameworks as useful versus diagnostic frameworks as limiting; and institutionally-defined identity versus self-defined identity. In terms of these polarised perceptions, an overarching theme of the medicalisation versus the demedicalisation of schizophrenia was identified. Therefore, the perceptions of clinical psychologists in this study were largely polarised towards either a medicalisation of the phenomenon of schizophrenia or a demedicalisation of it. However, perceptions were also identified that evidenced an integration of the two sides of the polarities, and a holding of tension between seemingly incompatible or incongruent frameworks. The participants perceived psychologists as positioned in the middle ground between the medicalisation and demedicalisation of schizophrenia in a biomedical psychiatric setting. In response to the call for a focus on the psychology of the person diagnosed with schizophrenia, the findings support both the value and the need for an “integration of polarised perceptions”, “holding of the tension”, and “middle ground positioning” of clinicians between medicalised and demedicalised aspects of the phenomenon of schizophrenia.
- Full Text:
- Date Issued: 2019
- Authors: Hamman, Colette
- Date: 2019
- Subjects: Schizophrenia -- Diagnosis -- South Africa , Schizophrenia -- Treatment -- South Africa , Schizophrenics -- Rehabilitation -- South Africa , Schizophrenics -- South Africa -- Case studies
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/71398 , vital:29845
- Description: Numerous international and South African scholars are critical of the dominant research on the phenomenon of schizophrenia. Rather than refuting dominant biomedical psychiatric conceptualisations of schizophrenia, there is a call for incorporating a focus on the psychology of the person diagnosed with schizophrenia. In South Africa, the integration of the psychosocial components of psychotic experiences into the understanding and treatment of psychosis are still neglected in biomedically-focused psychiatric settings. In relation to this call, the role of clinical psychologists working within these settings seems pertinent. Against this background, this study aimed to explore and describe the perceptions of clinical psychologists, working in a psychiatric setting in South Africa, in relation to the phenomenon of schizophrenia. Informed by a social constructionist theoretical framework, this study utilised a qualitative research design and a semi-structured interview schedule. In-depth, individual interviews were conducted with three clinical psychologists and the transcribed interviews were analysed using thematic analysis. From the data, perceptions were identified as largely polarised in relation to the phenomenon of schizophrenia. These polarised perceptions included: Physical impact of schizophrenia versus social impact of schizophrenia; rehabilitation of schizophrenia versus recovery within schizophrenia; diagnostic frameworks as useful versus diagnostic frameworks as limiting; and institutionally-defined identity versus self-defined identity. In terms of these polarised perceptions, an overarching theme of the medicalisation versus the demedicalisation of schizophrenia was identified. Therefore, the perceptions of clinical psychologists in this study were largely polarised towards either a medicalisation of the phenomenon of schizophrenia or a demedicalisation of it. However, perceptions were also identified that evidenced an integration of the two sides of the polarities, and a holding of tension between seemingly incompatible or incongruent frameworks. The participants perceived psychologists as positioned in the middle ground between the medicalisation and demedicalisation of schizophrenia in a biomedical psychiatric setting. In response to the call for a focus on the psychology of the person diagnosed with schizophrenia, the findings support both the value and the need for an “integration of polarised perceptions”, “holding of the tension”, and “middle ground positioning” of clinicians between medicalised and demedicalised aspects of the phenomenon of schizophrenia.
- Full Text:
- Date Issued: 2019
Collaborative health literacy development: a World Health Organization workplace health promotion approach to address tobacco use
- Authors: Duxbury, Theodore Orlando
- Date: 2019
- Subjects: Tobacco use -- Health aspects , Smoking -- Health aspects , Employee health promotion , Employee health promotion -- Computer programs , Rhodes University -- Employees -- Tobacco use
- Language: English
- Type: text , Thesis , Masters , MPharm
- Identifier: http://hdl.handle.net/10962/104116 , vital:29930
- Description: Background: Non-Communicable Diseases (NCDs) are a major global public health threat and tobacco use in particular is the leading cause of preventable illness and mortality globally. Furthermore, vulnerable and socially disadvantaged people get sicker and die sooner, especially because they are at higher risk of being exposed to harmful products such as tobacco and have limited access to health services. Tobacco use also has a major impact on the workplace, adversely affecting work productivity and increasing absenteeism. Both the living and work environments, therefore, play an important role in contributing towards the NCD epidemic. Demographics, culture, behaviour change reluctance and health literacy are all factors which exacerbate tobacco prevalence in South Africa. Workplace health promotion, however, is not well established in many workplaces. This study aimed to develop, implement and evaluate the effectiveness of a culturallysensitive and contextually-appropriate collaborative workplace health promotion literacy programme on tobacco use, utilizing tailored health information leaflets and the Rhodes University peer educators support staff, guided by the World Health Organization Workplace Health Promotion Framework. Method: The research was conducted using a participatory action research approach, which involved four phases: Firstly, the Exploratory phase assessed tobacco-related health promotion policies and practices at Rhodes University; and established facilitating and constraining factors related to tobacco use. Secondly, the Educational health promotion phase involved designing and testing a health promotion educational intervention to address tobacco use related challenges, which took the form of culturally sensitive and appropriate health information leaflets to be used as an educational intervention Thirdly, in the Implementation phase health promotion training workshops were conducted with volunteering Rhodes University Peer Educators. Finally, an Evaluation phase involved evaluating the tobacco health promotion programme presented to the Rhodes University Peer Educators through a focus group discussion; and evaluating Peer Educator recall on the tobacco related health information discussed during the training workshops through a post-post intervention questionnaire. Eight semi-structured interviews (SSIs) and seven focus group discussions (FGDs) were conducted with support staff, peer educators and key stakeholders to establish the need for a comprehensive workplace health promotion initiative, and to identify the facilitating and constraining factors to conducting such an initiative on tobacco use at the University. Three health information leaflets (HILs) were developed collaboratively with the Peer Educators following a series of scientific, end-user testing approaches. The HILs were tested for readability, comprehension, actionability and suitability. A four-day health promotion training programme was conducted to improve user friendliness, memory retention and recall of the HILs by the peer educators and to improve tobacco related health literacy aspects. The participants’ memory recall was evaluated using a pre- and post-, and post-post-intervention questionnaire to evaluate knowledge transfer. The study participants were also equipped with the completed HILs to distribute to their peers and to use as reference sources of information when needed in future. Results: The peer educators and institutional management supported the need for a tobacco workplace health promotion intervention. The intervention and evaluation phase of this study proved that health information material developed was readable, actionable, suitable, userfriendly, culturally sensitive and contextually appropriate. The workshops resulted in a significant increase in the participants’ tobacco related health knowledge. Through the adoption of a collaborative approach to the research, the participants felt empowered and ready to be agents of change amongst their peers in the workplace. Recommendations: The collective use of external expert reviewers, end-user testing techniques and validated computer programmes are recommended to improve the validity of health promotion research outcomes. A longitudinal study that focus on behaviour change, specifically, with health evaluation and monitoring aspects could be conducted as the next step to this study.
- Full Text:
- Date Issued: 2019
- Authors: Duxbury, Theodore Orlando
- Date: 2019
- Subjects: Tobacco use -- Health aspects , Smoking -- Health aspects , Employee health promotion , Employee health promotion -- Computer programs , Rhodes University -- Employees -- Tobacco use
- Language: English
- Type: text , Thesis , Masters , MPharm
- Identifier: http://hdl.handle.net/10962/104116 , vital:29930
- Description: Background: Non-Communicable Diseases (NCDs) are a major global public health threat and tobacco use in particular is the leading cause of preventable illness and mortality globally. Furthermore, vulnerable and socially disadvantaged people get sicker and die sooner, especially because they are at higher risk of being exposed to harmful products such as tobacco and have limited access to health services. Tobacco use also has a major impact on the workplace, adversely affecting work productivity and increasing absenteeism. Both the living and work environments, therefore, play an important role in contributing towards the NCD epidemic. Demographics, culture, behaviour change reluctance and health literacy are all factors which exacerbate tobacco prevalence in South Africa. Workplace health promotion, however, is not well established in many workplaces. This study aimed to develop, implement and evaluate the effectiveness of a culturallysensitive and contextually-appropriate collaborative workplace health promotion literacy programme on tobacco use, utilizing tailored health information leaflets and the Rhodes University peer educators support staff, guided by the World Health Organization Workplace Health Promotion Framework. Method: The research was conducted using a participatory action research approach, which involved four phases: Firstly, the Exploratory phase assessed tobacco-related health promotion policies and practices at Rhodes University; and established facilitating and constraining factors related to tobacco use. Secondly, the Educational health promotion phase involved designing and testing a health promotion educational intervention to address tobacco use related challenges, which took the form of culturally sensitive and appropriate health information leaflets to be used as an educational intervention Thirdly, in the Implementation phase health promotion training workshops were conducted with volunteering Rhodes University Peer Educators. Finally, an Evaluation phase involved evaluating the tobacco health promotion programme presented to the Rhodes University Peer Educators through a focus group discussion; and evaluating Peer Educator recall on the tobacco related health information discussed during the training workshops through a post-post intervention questionnaire. Eight semi-structured interviews (SSIs) and seven focus group discussions (FGDs) were conducted with support staff, peer educators and key stakeholders to establish the need for a comprehensive workplace health promotion initiative, and to identify the facilitating and constraining factors to conducting such an initiative on tobacco use at the University. Three health information leaflets (HILs) were developed collaboratively with the Peer Educators following a series of scientific, end-user testing approaches. The HILs were tested for readability, comprehension, actionability and suitability. A four-day health promotion training programme was conducted to improve user friendliness, memory retention and recall of the HILs by the peer educators and to improve tobacco related health literacy aspects. The participants’ memory recall was evaluated using a pre- and post-, and post-post-intervention questionnaire to evaluate knowledge transfer. The study participants were also equipped with the completed HILs to distribute to their peers and to use as reference sources of information when needed in future. Results: The peer educators and institutional management supported the need for a tobacco workplace health promotion intervention. The intervention and evaluation phase of this study proved that health information material developed was readable, actionable, suitable, userfriendly, culturally sensitive and contextually appropriate. The workshops resulted in a significant increase in the participants’ tobacco related health knowledge. Through the adoption of a collaborative approach to the research, the participants felt empowered and ready to be agents of change amongst their peers in the workplace. Recommendations: The collective use of external expert reviewers, end-user testing techniques and validated computer programmes are recommended to improve the validity of health promotion research outcomes. A longitudinal study that focus on behaviour change, specifically, with health evaluation and monitoring aspects could be conducted as the next step to this study.
- Full Text:
- Date Issued: 2019
Colloquial terms used in young adults’ talk about sexual practices, sexual subjectivities and sexual desires’
- Authors: Robertson, Cassandra Ann
- Date: 2019
- Subjects: Youth -- Sexual behavior , Sex in popular culture , Communication and sex , Language and sex
- Language: English
- Type: text , Thesis , Masters , MSocSc
- Identifier: http://hdl.handle.net/10962/96551 , vital:31293
- Description: Much of the growth in sexualities‘ research has taken the form of large scale surveys, but there is also increased interest in qualitative approaches that provide useful insights into the experiential and subjective aspects of sexuality, and illuminate the social and cultural contexts shaping these experiences. The reason for this research is to provide a richer understanding of the language that young people employ when speaking about sexuality. This study examines young adults‘ talk about sexualities with a special focus on the way in which colloquial terms are deployed in this talk and through the presence of gendered and/or heteronormative assumptions. Data consisted of posts off a student-led social media site and the study design employed was a validity check group interview. The social media site allowed its followers to post anonymously about a range of sexualities related issues. Data were analysed thematically, using a deductive, critical, and post-structuralist approach with key insights drawn on from Michael Foucault, Adrienne Rich, Gayle Rubin, Judith Butler and Rosalind Gill. Three overarching themes emerged: young adults spoke to sexual practices, sexual subjectivities and sexual desires. A major focus of this talk is casual sex. This talk showed that there are attempts to undermine gendered and heteronormative power relations, for example, non-normative sexual experiences were not seen as deviant, although those who were engaging in monogamy and casual sex were constructed as deviant sexual subjects. Yet underpinning of these power relations still took place, for example, in the female missing discourse of desire, the internalisation of male sexual desires over female sexual desires and the sexual double standard. There was a clear divide between the sexual practices and sexual subjectivities that were considered to be good and bad. This research therefore has the potential to benefit sexuality interventions by bringing into sharp focus the actual experiences of young adults.
- Full Text:
- Date Issued: 2019
- Authors: Robertson, Cassandra Ann
- Date: 2019
- Subjects: Youth -- Sexual behavior , Sex in popular culture , Communication and sex , Language and sex
- Language: English
- Type: text , Thesis , Masters , MSocSc
- Identifier: http://hdl.handle.net/10962/96551 , vital:31293
- Description: Much of the growth in sexualities‘ research has taken the form of large scale surveys, but there is also increased interest in qualitative approaches that provide useful insights into the experiential and subjective aspects of sexuality, and illuminate the social and cultural contexts shaping these experiences. The reason for this research is to provide a richer understanding of the language that young people employ when speaking about sexuality. This study examines young adults‘ talk about sexualities with a special focus on the way in which colloquial terms are deployed in this talk and through the presence of gendered and/or heteronormative assumptions. Data consisted of posts off a student-led social media site and the study design employed was a validity check group interview. The social media site allowed its followers to post anonymously about a range of sexualities related issues. Data were analysed thematically, using a deductive, critical, and post-structuralist approach with key insights drawn on from Michael Foucault, Adrienne Rich, Gayle Rubin, Judith Butler and Rosalind Gill. Three overarching themes emerged: young adults spoke to sexual practices, sexual subjectivities and sexual desires. A major focus of this talk is casual sex. This talk showed that there are attempts to undermine gendered and heteronormative power relations, for example, non-normative sexual experiences were not seen as deviant, although those who were engaging in monogamy and casual sex were constructed as deviant sexual subjects. Yet underpinning of these power relations still took place, for example, in the female missing discourse of desire, the internalisation of male sexual desires over female sexual desires and the sexual double standard. There was a clear divide between the sexual practices and sexual subjectivities that were considered to be good and bad. This research therefore has the potential to benefit sexuality interventions by bringing into sharp focus the actual experiences of young adults.
- Full Text:
- Date Issued: 2019
Communicating in/from the Cave: a communication for development/social change project aimed at enhancing communication, action and learning within the science cave, a learner-led Grade 10 science club in a public school in Makhanda
- Authors: Bombi, Thandi
- Date: 2019
- Subjects: Science -- Study and teaching (Secondary) -- South Africa , Communication in science -- South Africa , Science -- Study and teaching (Secondary) -- South Africa -- Makhanda , Communication in science -- South Africa -- Makhanda , Student centered learning -- South Africa , Student centered learning-- South Africa -- Makhanda
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/96837 , vital:31330
- Description: This research seeks to design, execute and reflect on a process where the principles and techniques of Communication for Development and Social Change are applied to enhance, support and develop qualitative changes within a learner-led Grade 10 science club at a public school in Makhanda. It draws and reflects on an ethnographic action research (Tacchi et al 2003) cycle proposed to explore the club’s communicative ecology (Foth & Hearn 2007) and resources, and understand how these have the potential to encourage the expression of voice (Couldry 2010: 580) and participation (Carpentier, 2011) in the members of the club. The research then attempts to understand the kind of communication, action and learning that takes place as well as the ways in which the framework is able to support the club (or not). The research uses an ethnographic narrative, told from the perspective of the researcher informed by field notes, interviews and participant reflections written during the intervention. This narrative, alongside an analytical summery of the club’s complex communicative ecology, tells the story of a club building confidence within a closed group and using that to connect with a wider public, articulating its needs, resources and potential supporting stakeholders for the club’s future development. The club is able to share its achievements with a community of peers and uses the platform of Facebook, to communicate with and inspire other like-minded people with an interest in science and their community.
- Full Text:
- Date Issued: 2019
- Authors: Bombi, Thandi
- Date: 2019
- Subjects: Science -- Study and teaching (Secondary) -- South Africa , Communication in science -- South Africa , Science -- Study and teaching (Secondary) -- South Africa -- Makhanda , Communication in science -- South Africa -- Makhanda , Student centered learning -- South Africa , Student centered learning-- South Africa -- Makhanda
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/96837 , vital:31330
- Description: This research seeks to design, execute and reflect on a process where the principles and techniques of Communication for Development and Social Change are applied to enhance, support and develop qualitative changes within a learner-led Grade 10 science club at a public school in Makhanda. It draws and reflects on an ethnographic action research (Tacchi et al 2003) cycle proposed to explore the club’s communicative ecology (Foth & Hearn 2007) and resources, and understand how these have the potential to encourage the expression of voice (Couldry 2010: 580) and participation (Carpentier, 2011) in the members of the club. The research then attempts to understand the kind of communication, action and learning that takes place as well as the ways in which the framework is able to support the club (or not). The research uses an ethnographic narrative, told from the perspective of the researcher informed by field notes, interviews and participant reflections written during the intervention. This narrative, alongside an analytical summery of the club’s complex communicative ecology, tells the story of a club building confidence within a closed group and using that to connect with a wider public, articulating its needs, resources and potential supporting stakeholders for the club’s future development. The club is able to share its achievements with a community of peers and uses the platform of Facebook, to communicate with and inspire other like-minded people with an interest in science and their community.
- Full Text:
- Date Issued: 2019
Composition portfolio
- Authors: Cooper, Corinne Jane
- Date: 2019
- Subjects: Xhosa (African people) -- Music , Musical bow -- South Africa -- Eastern Cape , Sound recordings in ethnomusicology -- South Africa , Dywili, Nofinishi. The bow project , Music -- South Africa -- Eastern Cape
- Language: English
- Type: text , Thesis , Masters , MMus
- Identifier: http://hdl.handle.net/10962/168338 , vital:41568
- Description: In June 2014, I was introduced to Christine Dixie by a film maker I had worked with on a previous project. Christine was looking for a composer who could arrange a soundtrack around musical themes that she had commissioned from Jared Lang to accompany her video installation To Be King (Dixie 2014. Jared composed five different melodies that I wove into a palette of sounds that comprised the soundtrack. To Be King was exhibited at the National Arts Festival in 2014 as part of the Main Festival. It moved to Cape Town in 2015 and 2017, to Venice and London in 2017, and to Lithuania in 2018. In 2017, Christine approached me to compose a soundtrack for a different work, based again on seventeenth century Spanish artist, Velázquez’ painting ‘Las Meninas’ (1656), but this time, using a series of sculptures representing the different figures in the painting, a reinterpretation with strong Eastern Cape (South Africa) themes and associations. Christine proposed reimagining the figures in the painting by clothing them in Shweshwe 1 material and placing African masks on each of them, masks that she had sought out during her travels around Africa. The use of Shweshwe material, ties the figures very closely to the Eastern Cape, and in particular, close to where I grew up in Alice, just 60 kilometres away from where it is manufactured in King William’s Town. Alice is important in the unfolding of this portfolio as Ntsikana, purportedly the first Xhosa person to be converted to Christianity and a prophet, lived in Peddie (which is about 70 kilometers from Grahamstown and Rhodes University) and Gqora, near the Kat River District which is located in the Amathola District near Alice. (Kumalo 2015, p.26). Alice is steeped in history, and is the town where Lovedale Mission Station was founded in 1824 and later, the Lovedale Press in 1861. Therefore, this project felt close to my roots, hence this interaction between Western and African cultures is very relevant to my world view and has impacted on my scoring of this music. I was initially challenged by the idea that the project would require a deeper understanding of traditional Xhosa music and while I had been exposed to Xhosa culture while growing up in Alice, my formative years were largely shaped by the culture of my Christian parents who immigrated to South Africa from England during the 1960s. During the first decade of the twentieth century, in my capacity as a sound engineer, I was tasked with recording and mastering a double CD called The Bow Project. Various South African composers were invited to transcribe and paraphrase or reimagine traditional Xhosa bow music for the classical string quartet. The uhadi songs 2 of Nofinishi Dywili formed the basis for many of these intercultural explorations, and I recorded and mastered the string quartets as well as 12 individual recordings of Dywili’s music. I spent many hours listening to Dywili’s recordings while I mastered them, but though I was very familiar with how they sounded, I realised, as I started compiling this portfolio, that I was not familiar with their notation and rhythmic structures. I approach sound engineering with a very different ear and sonic perspective to that of a composer. To learn more about uhadi bow music I visited the International Library of African Music (ILAM) which is housed by Rhodes University in Grahamstown, Eastern Cape. Here I consulted with sound engineer and African music specialist, Elijah Madiba, on Xhosa instruments and traditional music-making. With Madiba’s assistance I listened carefully to different bow performances and examined a variety of instruments. After this introduction I loaned a selection of recordings from the ILAM collection and listened to them as carefully as I could. Every time I listened, I seemed to hear something different, both melodically and rhythmically. To gain a deeper understanding of how this music was created I decided to transcribe some of the songs. Following a steep learning curve I completed transcriptions of two songs with my transcriptions including a wealth of vocal parts. As my ears grew accustomed to the sound world I heard additional counter melodies. Notating the rhythms using staff notation was challenging, as this music is created according to a different format, but I am familiar with staff notation and if I was going to use this material while composing then I needed to remain with that which was familiar. I finally settled on notating with shifting time signatures and the first song is scored in bars of 3/4, 4/4, and 2/4 while the other song uses 3/4, 2/4. It was a very worthwhile exercise and after completion I humbly set about composing the eleven pieces that would musically express Dixie’s new work: Worlding the White Spirit Maiden (2019).
- Full Text:
- Date Issued: 2019
- Authors: Cooper, Corinne Jane
- Date: 2019
- Subjects: Xhosa (African people) -- Music , Musical bow -- South Africa -- Eastern Cape , Sound recordings in ethnomusicology -- South Africa , Dywili, Nofinishi. The bow project , Music -- South Africa -- Eastern Cape
- Language: English
- Type: text , Thesis , Masters , MMus
- Identifier: http://hdl.handle.net/10962/168338 , vital:41568
- Description: In June 2014, I was introduced to Christine Dixie by a film maker I had worked with on a previous project. Christine was looking for a composer who could arrange a soundtrack around musical themes that she had commissioned from Jared Lang to accompany her video installation To Be King (Dixie 2014. Jared composed five different melodies that I wove into a palette of sounds that comprised the soundtrack. To Be King was exhibited at the National Arts Festival in 2014 as part of the Main Festival. It moved to Cape Town in 2015 and 2017, to Venice and London in 2017, and to Lithuania in 2018. In 2017, Christine approached me to compose a soundtrack for a different work, based again on seventeenth century Spanish artist, Velázquez’ painting ‘Las Meninas’ (1656), but this time, using a series of sculptures representing the different figures in the painting, a reinterpretation with strong Eastern Cape (South Africa) themes and associations. Christine proposed reimagining the figures in the painting by clothing them in Shweshwe 1 material and placing African masks on each of them, masks that she had sought out during her travels around Africa. The use of Shweshwe material, ties the figures very closely to the Eastern Cape, and in particular, close to where I grew up in Alice, just 60 kilometres away from where it is manufactured in King William’s Town. Alice is important in the unfolding of this portfolio as Ntsikana, purportedly the first Xhosa person to be converted to Christianity and a prophet, lived in Peddie (which is about 70 kilometers from Grahamstown and Rhodes University) and Gqora, near the Kat River District which is located in the Amathola District near Alice. (Kumalo 2015, p.26). Alice is steeped in history, and is the town where Lovedale Mission Station was founded in 1824 and later, the Lovedale Press in 1861. Therefore, this project felt close to my roots, hence this interaction between Western and African cultures is very relevant to my world view and has impacted on my scoring of this music. I was initially challenged by the idea that the project would require a deeper understanding of traditional Xhosa music and while I had been exposed to Xhosa culture while growing up in Alice, my formative years were largely shaped by the culture of my Christian parents who immigrated to South Africa from England during the 1960s. During the first decade of the twentieth century, in my capacity as a sound engineer, I was tasked with recording and mastering a double CD called The Bow Project. Various South African composers were invited to transcribe and paraphrase or reimagine traditional Xhosa bow music for the classical string quartet. The uhadi songs 2 of Nofinishi Dywili formed the basis for many of these intercultural explorations, and I recorded and mastered the string quartets as well as 12 individual recordings of Dywili’s music. I spent many hours listening to Dywili’s recordings while I mastered them, but though I was very familiar with how they sounded, I realised, as I started compiling this portfolio, that I was not familiar with their notation and rhythmic structures. I approach sound engineering with a very different ear and sonic perspective to that of a composer. To learn more about uhadi bow music I visited the International Library of African Music (ILAM) which is housed by Rhodes University in Grahamstown, Eastern Cape. Here I consulted with sound engineer and African music specialist, Elijah Madiba, on Xhosa instruments and traditional music-making. With Madiba’s assistance I listened carefully to different bow performances and examined a variety of instruments. After this introduction I loaned a selection of recordings from the ILAM collection and listened to them as carefully as I could. Every time I listened, I seemed to hear something different, both melodically and rhythmically. To gain a deeper understanding of how this music was created I decided to transcribe some of the songs. Following a steep learning curve I completed transcriptions of two songs with my transcriptions including a wealth of vocal parts. As my ears grew accustomed to the sound world I heard additional counter melodies. Notating the rhythms using staff notation was challenging, as this music is created according to a different format, but I am familiar with staff notation and if I was going to use this material while composing then I needed to remain with that which was familiar. I finally settled on notating with shifting time signatures and the first song is scored in bars of 3/4, 4/4, and 2/4 while the other song uses 3/4, 2/4. It was a very worthwhile exercise and after completion I humbly set about composing the eleven pieces that would musically express Dixie’s new work: Worlding the White Spirit Maiden (2019).
- Full Text:
- Date Issued: 2019
Cultural clusters as a local economic development strategy in rural, small town areas: the Sarah Baartman District in the Eastern Cape of South Africa
- Authors: Drummond, Fiona Jane
- Date: 2019
- Subjects: Cultural industries -- South Africa -- Eastern Cape , Creative ability -- Economic aspects -- South Africa -- Eastern Cape , Arts -- Economic aspects -- South Africa -- Eastern Cape , Culture -- Economic aspects -- South Africa -- Eastern Cape , Economic development -- South Africa -- Eastern Cape , Economic development projects -- South Africa -- Eastern Cape
- Language: English
- Type: text , Thesis , Masters , MCom
- Identifier: http://hdl.handle.net/10962/71568 , vital:29879
- Description: It is increasingly recognized that the cultural and creative industries (CCIs) can play an important role in economic growth and development. Governments around the world, including South Africa, are implementing culture‐led economic growth and development strategies on national and regional scales. CCIs tend to cluster around large cities because of existing hard and soft infrastructure such as networking advantages and access to skilled labour, however, much less is known about the potential of the CCIs to drive rural development. This thesis thus investigates the potential of the CCIs to cluster in small towns and rural areas. Moreover, it examines the relationship between the CCIs and socio‐economic development. The CCIs have been touted as a catalyst for economic growth and development and so have often been used in urban regeneration schemes. The Sarah Baartman District (SBD) of South Africa’s Eastern Cape has identified culture as a potential new economic driver. Establishing a new development path is necessary as the former economic mainstay, agriculture, has declined in the region, creating poverty and unemployment problems. However, the SBD has only small towns which, according to the literature, are not suited to CCI clustering. Despite this, there is evidence of cultural clustering in some of the SBD’s small towns like Nieu Bethesda and Bathurst. This research therefore conducted an audit of the CCIs in the district and used geographic information systems (GIS) to map their locations by UNESCO Framework of Cultural Statistics (FCS) domains in order to determine the extent to which clustering has occurred in a small town setting. The audit identified 1 048 CCIs operating in the district and determined that clustering is possible within some small towns, depending on their demographic, economic, social, geographic and historic characteristics. For small towns where clusters exist or the potential for cluster formation is present, the domains in which the town holds a comparative advantage, based on domain proportions and location quotients, should be pursued for local economic development (LED). In this case, Visual Arts and Crafts and Cultural Heritage were prominent throughout the district while Design and Creative Services and Performance and Celebration had small regional concentrations. Theory suggests that the presence of CCIs is linked to higher levels of economic development as the creative class is more likely to be attracted to more highly developed areas, usually large cities. Furthermore, spillover effects from cultural activity promotes further development under the virtuous cycle. To investigate the relationship between CCI clusters and socio‐economic development, the locational data of municipal level CCI numbers is overlaid with a regional development indicator, a socio‐economic status index, which is based on census data and includes economic and social components. Results show that there is a general positive trend of CCIs locating in larger numbers (clustering) in areas with higher socio‐economic development performances.
- Full Text:
- Date Issued: 2019
- Authors: Drummond, Fiona Jane
- Date: 2019
- Subjects: Cultural industries -- South Africa -- Eastern Cape , Creative ability -- Economic aspects -- South Africa -- Eastern Cape , Arts -- Economic aspects -- South Africa -- Eastern Cape , Culture -- Economic aspects -- South Africa -- Eastern Cape , Economic development -- South Africa -- Eastern Cape , Economic development projects -- South Africa -- Eastern Cape
- Language: English
- Type: text , Thesis , Masters , MCom
- Identifier: http://hdl.handle.net/10962/71568 , vital:29879
- Description: It is increasingly recognized that the cultural and creative industries (CCIs) can play an important role in economic growth and development. Governments around the world, including South Africa, are implementing culture‐led economic growth and development strategies on national and regional scales. CCIs tend to cluster around large cities because of existing hard and soft infrastructure such as networking advantages and access to skilled labour, however, much less is known about the potential of the CCIs to drive rural development. This thesis thus investigates the potential of the CCIs to cluster in small towns and rural areas. Moreover, it examines the relationship between the CCIs and socio‐economic development. The CCIs have been touted as a catalyst for economic growth and development and so have often been used in urban regeneration schemes. The Sarah Baartman District (SBD) of South Africa’s Eastern Cape has identified culture as a potential new economic driver. Establishing a new development path is necessary as the former economic mainstay, agriculture, has declined in the region, creating poverty and unemployment problems. However, the SBD has only small towns which, according to the literature, are not suited to CCI clustering. Despite this, there is evidence of cultural clustering in some of the SBD’s small towns like Nieu Bethesda and Bathurst. This research therefore conducted an audit of the CCIs in the district and used geographic information systems (GIS) to map their locations by UNESCO Framework of Cultural Statistics (FCS) domains in order to determine the extent to which clustering has occurred in a small town setting. The audit identified 1 048 CCIs operating in the district and determined that clustering is possible within some small towns, depending on their demographic, economic, social, geographic and historic characteristics. For small towns where clusters exist or the potential for cluster formation is present, the domains in which the town holds a comparative advantage, based on domain proportions and location quotients, should be pursued for local economic development (LED). In this case, Visual Arts and Crafts and Cultural Heritage were prominent throughout the district while Design and Creative Services and Performance and Celebration had small regional concentrations. Theory suggests that the presence of CCIs is linked to higher levels of economic development as the creative class is more likely to be attracted to more highly developed areas, usually large cities. Furthermore, spillover effects from cultural activity promotes further development under the virtuous cycle. To investigate the relationship between CCI clusters and socio‐economic development, the locational data of municipal level CCI numbers is overlaid with a regional development indicator, a socio‐economic status index, which is based on census data and includes economic and social components. Results show that there is a general positive trend of CCIs locating in larger numbers (clustering) in areas with higher socio‐economic development performances.
- Full Text:
- Date Issued: 2019
Deconstructing “the South African jazz feel”: roots, rhythms and features of South African jazz
- Authors: Thorpe, Christopher John
- Date: 2019
- Subjects: Jazz -- History and criticism , Jazz -- African influences , Jazz -- Africa --History and criticism , Jazz -- South Africa --History and criticism
- Language: English
- Type: text , Thesis , Masters , MMus
- Identifier: http://hdl.handle.net/10962/76649 , vital:30612
- Description: South African jazz has established itself as a distinct and influential genre in modern popular music that merges musical elements from traditional South African musics with influences from U.S.-American jazz. Formed during a time of extreme social inequality in a divided country, South African jazz became the soundtrack of the struggle against social injustice and racial oppression, and was brought to international attention by artists such as Hugh Masekela, Miriam Makeba, and Abdullah Ibrahim who gave poignant musical expression to the hardships of the time. South African jazz is celebrated for its unique sound, original catalogue and all-important “feel”. To many listeners, performers and musicologists, it is this concept of feel that makes South African jazz so distinctive and inimitable. To date, however, much of the scholarly and popular literature on South African jazz has centred on the historical, social and political aspects of the music, with less attention given to close musical-textual analysis. A few studies have considered the melodic and harmonic language of iconic saxophonists and bass players but there are – to date – no close studies of rhythm and feel in South African jazz. Beginning to address this gap in the literature, this study uncovers some of the elements that constitute the South African jazz feel through close rhythmic and more general musical analyses of a selection of South African jazz recordings.
- Full Text:
- Date Issued: 2019
- Authors: Thorpe, Christopher John
- Date: 2019
- Subjects: Jazz -- History and criticism , Jazz -- African influences , Jazz -- Africa --History and criticism , Jazz -- South Africa --History and criticism
- Language: English
- Type: text , Thesis , Masters , MMus
- Identifier: http://hdl.handle.net/10962/76649 , vital:30612
- Description: South African jazz has established itself as a distinct and influential genre in modern popular music that merges musical elements from traditional South African musics with influences from U.S.-American jazz. Formed during a time of extreme social inequality in a divided country, South African jazz became the soundtrack of the struggle against social injustice and racial oppression, and was brought to international attention by artists such as Hugh Masekela, Miriam Makeba, and Abdullah Ibrahim who gave poignant musical expression to the hardships of the time. South African jazz is celebrated for its unique sound, original catalogue and all-important “feel”. To many listeners, performers and musicologists, it is this concept of feel that makes South African jazz so distinctive and inimitable. To date, however, much of the scholarly and popular literature on South African jazz has centred on the historical, social and political aspects of the music, with less attention given to close musical-textual analysis. A few studies have considered the melodic and harmonic language of iconic saxophonists and bass players but there are – to date – no close studies of rhythm and feel in South African jazz. Beginning to address this gap in the literature, this study uncovers some of the elements that constitute the South African jazz feel through close rhythmic and more general musical analyses of a selection of South African jazz recordings.
- Full Text:
- Date Issued: 2019
Determining the hydrological functioning of the palmiet wetlands in the Eastern and Western Cape South Africa
- Authors: Smith, Caitlin
- Date: 2019
- Subjects: Wetlands -- South Africa -- Eastern Cape , Wetland ecology -- South Africa -- Eastern Cape , Wetland management -- South Africa -- Eastern Cape , Prioniaceae -- South Africa -- Eastern Cape , Prionium serratum -- South Africa -- Eastern Cape
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/95956 , vital:31218
- Description: Wetlands provide a range of supporting, regulating and provisioning ecosystem services, including hydrological benefits such as flood attenuation and sustaining base flows. Despite their value, wetlands are one of the most vulnerable ecosystems in South Africa. Palmiet wetlands in the Eastern and Western Cape are particularly threatened. Palmiet (Prionium serratum) is a robust perennial plant that is endemic to wetlands and rivers located in the sandstones and quartzites of the Table Mountain Group (TMG), in the Eastern and Western Cape as well as the Natal Group sandstones in KwaZulu-Natal. Palmiet is described as an ecosystem engineer because of its ability to alter its environment and create large valley-bottom wetlands. The Krom River is an important water source for the city of Port Elizabeth and there has been a decline in palmiet wetlands along the Krom River as a result of alien vegetation invasion, agricultural activity, and gully erosion. Working for Water has been clearing alien vegetation and Working for Wetlands has been installing rehabilitation structures in the Krom River catchment for a number of years. There are, however, serious knowledge gaps in the understanding of palmiet wetland structure and function, particularly in respect of the hydrological functioning of these wetland systems. The aim of this study was to investigate the hydrology (surface and groundwater) behind these wetland systems. The investigation focussed on small-scale dynamics of the palmiet wetland system in order to increase general understanding of the surface water and groundwater processes of these wetland systems. Field work was concentrated on the Kompanjiesdrif and Krugersland palmiet wetlands in the upper K90A Krom River catchment. The investigation involved the installation of piezometers, water quality and stable isotope sampling and analysis, an Electrical Resistivity Tomography survey, and hydrological and mixing cell modelling. The results of the investigation indicate that the hydrological functioning of palmiet wetlands is closely linked with high sub-surface discharges typically associated with TMG aquifers. It is proposed that the palmiet wetlands are sustained by significant amounts of sub-surface water (both groundwater and interflow) moving through preferential flow paths in the alluvial fans and tributaries, which are in turn sustained by groundwater discharge from the surrounding sandstones and quartzites of the Nardouw Sub-group and Peninsula Formation. The palmiet wetlands clearly retain a significant amount of water, leading to the maintenance of prolonged flows, and a larger baseflow. However, it is hypothesised that the occurrence of palmiet as the dominant species in these wetlands is due to the sustained low flows related to catchment geology and high hydrological connectivity between the catchment and the wetland that is enabled by flow paths that allow the free flow of water from the catchment to the wetland. It is further proposed that palmiet is possibly more reliant on a consistent water supply for its existence and survival than it is on acidic nutrient-poor water and soils as stated by other authors.
- Full Text:
- Date Issued: 2019
- Authors: Smith, Caitlin
- Date: 2019
- Subjects: Wetlands -- South Africa -- Eastern Cape , Wetland ecology -- South Africa -- Eastern Cape , Wetland management -- South Africa -- Eastern Cape , Prioniaceae -- South Africa -- Eastern Cape , Prionium serratum -- South Africa -- Eastern Cape
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/95956 , vital:31218
- Description: Wetlands provide a range of supporting, regulating and provisioning ecosystem services, including hydrological benefits such as flood attenuation and sustaining base flows. Despite their value, wetlands are one of the most vulnerable ecosystems in South Africa. Palmiet wetlands in the Eastern and Western Cape are particularly threatened. Palmiet (Prionium serratum) is a robust perennial plant that is endemic to wetlands and rivers located in the sandstones and quartzites of the Table Mountain Group (TMG), in the Eastern and Western Cape as well as the Natal Group sandstones in KwaZulu-Natal. Palmiet is described as an ecosystem engineer because of its ability to alter its environment and create large valley-bottom wetlands. The Krom River is an important water source for the city of Port Elizabeth and there has been a decline in palmiet wetlands along the Krom River as a result of alien vegetation invasion, agricultural activity, and gully erosion. Working for Water has been clearing alien vegetation and Working for Wetlands has been installing rehabilitation structures in the Krom River catchment for a number of years. There are, however, serious knowledge gaps in the understanding of palmiet wetland structure and function, particularly in respect of the hydrological functioning of these wetland systems. The aim of this study was to investigate the hydrology (surface and groundwater) behind these wetland systems. The investigation focussed on small-scale dynamics of the palmiet wetland system in order to increase general understanding of the surface water and groundwater processes of these wetland systems. Field work was concentrated on the Kompanjiesdrif and Krugersland palmiet wetlands in the upper K90A Krom River catchment. The investigation involved the installation of piezometers, water quality and stable isotope sampling and analysis, an Electrical Resistivity Tomography survey, and hydrological and mixing cell modelling. The results of the investigation indicate that the hydrological functioning of palmiet wetlands is closely linked with high sub-surface discharges typically associated with TMG aquifers. It is proposed that the palmiet wetlands are sustained by significant amounts of sub-surface water (both groundwater and interflow) moving through preferential flow paths in the alluvial fans and tributaries, which are in turn sustained by groundwater discharge from the surrounding sandstones and quartzites of the Nardouw Sub-group and Peninsula Formation. The palmiet wetlands clearly retain a significant amount of water, leading to the maintenance of prolonged flows, and a larger baseflow. However, it is hypothesised that the occurrence of palmiet as the dominant species in these wetlands is due to the sustained low flows related to catchment geology and high hydrological connectivity between the catchment and the wetland that is enabled by flow paths that allow the free flow of water from the catchment to the wetland. It is further proposed that palmiet is possibly more reliant on a consistent water supply for its existence and survival than it is on acidic nutrient-poor water and soils as stated by other authors.
- Full Text:
- Date Issued: 2019
Discursive psychological analysis on the construction and performance of identity through rights talk on social media related to #FeesMustFall
- Authors: Mashaba, Tumelo Thabo
- Date: 2019
- Subjects: Identity , Right to education , Human rights , Social media -- Political aspects -- South Africa , College students -- Political activity -- South Africa , College students -- Attitudes -- South Africa , College students, Black -- Psychology -- South Africa , College students, Black -- Attitudes -- South Africa , College students -- Psychology -- South Africa , Student protestors -- Attitudes -- South Africa , Student movements -- South Africa , Internet and activisim -- South Africa , Internet in political campaigns -- South Africa , Higher education and state -- South Africa
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/96668 , vital:31306
- Description: #FeesMustFall emerged at the end of 2015 after an announcement that tuitions would increase. The student protests occurred across higher education institutions within the country in which mass shutdowns were initiated, there was the presence of violence and the use of social media. The protests occurred in 2016 but experienced a shift in tone in terms of the violence present in the protests. The research sought to unpack how identity was constructed and performed through rights talk in regards to #FeesMustFall on social media. The methodology worked from a social constructionist perspective where the research consisted of a discursive psychological analytical approach to the texts presented. The discursive repertoires that were identified were: emotions repertoire; struggle repertoire; apartheid repertoire; racial repertoire; and rights repertoire. The subject positions revealed through the repertoires indicated that protesters and supporters constructed and performed their identity in particular ways. They were positioned as black; working class; victims who are enacting a sense of agency; denied their rights; have moral authority and are a parallel to the protesters under apartheid. The repertoire of struggle, racial and apartheid all link with each other. The rights repertoire is the foundation and the emotions repertoire is the tone of the student protests.
- Full Text:
- Date Issued: 2019
- Authors: Mashaba, Tumelo Thabo
- Date: 2019
- Subjects: Identity , Right to education , Human rights , Social media -- Political aspects -- South Africa , College students -- Political activity -- South Africa , College students -- Attitudes -- South Africa , College students, Black -- Psychology -- South Africa , College students, Black -- Attitudes -- South Africa , College students -- Psychology -- South Africa , Student protestors -- Attitudes -- South Africa , Student movements -- South Africa , Internet and activisim -- South Africa , Internet in political campaigns -- South Africa , Higher education and state -- South Africa
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/96668 , vital:31306
- Description: #FeesMustFall emerged at the end of 2015 after an announcement that tuitions would increase. The student protests occurred across higher education institutions within the country in which mass shutdowns were initiated, there was the presence of violence and the use of social media. The protests occurred in 2016 but experienced a shift in tone in terms of the violence present in the protests. The research sought to unpack how identity was constructed and performed through rights talk in regards to #FeesMustFall on social media. The methodology worked from a social constructionist perspective where the research consisted of a discursive psychological analytical approach to the texts presented. The discursive repertoires that were identified were: emotions repertoire; struggle repertoire; apartheid repertoire; racial repertoire; and rights repertoire. The subject positions revealed through the repertoires indicated that protesters and supporters constructed and performed their identity in particular ways. They were positioned as black; working class; victims who are enacting a sense of agency; denied their rights; have moral authority and are a parallel to the protesters under apartheid. The repertoire of struggle, racial and apartheid all link with each other. The rights repertoire is the foundation and the emotions repertoire is the tone of the student protests.
- Full Text:
- Date Issued: 2019
Effect of substituents on the photophysical properties and nonlinear optical properties of asymmetrical zinc(II) phthalocyanine when conjugated to semiconductor quantum dots
- Authors: Mgidlana, Sithi
- Date: 2019
- Subjects: Nonlinear optics , Quantum dots , Phthalocyanines , Zinc
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/97152 , vital:31404
- Description: Various characterization techniques have been used to characterize the synthesized asymmetrical zinc phthalocyanines (ZnPc) derivatives. Techniques include Ultraviolet-visible (UV-vis) spectrophotometry, matrix assisted laser desorption time of flight mass spectrometry (MALD-TOF MS), proton nuclear magnetic resonance (1H-NMR), elemental analysis and Fourier-transform infra-red spectroscopy (FT-IR). The complexes are covalently linked to core/shell and core/shell/shell semiconductor quantum dots (SQDs) via amide bond formation. Photophysical properties of complexes improved in the presence of semiconductor quantum dots (SQDs). SQDs contain cadmium/telluride (CdTe) as core, coated in the first shell with zinc selenide (ZnSe) or zinc sulfide (ZnS) and with zinc oxide (ZnO) in second shell. The photophysical properties of the phthalocyanine (Pc) complexes and their conjugates with SQDs are investigated in solution. Triplet quantum yields of complexes improved in the presence of semiconductor quantum dots. The optical limiting behaviour of the Pc complexes and conjugates are assessed using the open aperture Z–scan technique at laser excitation wavelength of 532 nm with 10 ns pulse. Pcs complexes showed good nonlinear optical response with higher nonlinear absorption coefficient. The conjugates afforded higher nonlinear absorption coefficient than Pc complexes alone.
- Full Text:
- Date Issued: 2019
- Authors: Mgidlana, Sithi
- Date: 2019
- Subjects: Nonlinear optics , Quantum dots , Phthalocyanines , Zinc
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/97152 , vital:31404
- Description: Various characterization techniques have been used to characterize the synthesized asymmetrical zinc phthalocyanines (ZnPc) derivatives. Techniques include Ultraviolet-visible (UV-vis) spectrophotometry, matrix assisted laser desorption time of flight mass spectrometry (MALD-TOF MS), proton nuclear magnetic resonance (1H-NMR), elemental analysis and Fourier-transform infra-red spectroscopy (FT-IR). The complexes are covalently linked to core/shell and core/shell/shell semiconductor quantum dots (SQDs) via amide bond formation. Photophysical properties of complexes improved in the presence of semiconductor quantum dots (SQDs). SQDs contain cadmium/telluride (CdTe) as core, coated in the first shell with zinc selenide (ZnSe) or zinc sulfide (ZnS) and with zinc oxide (ZnO) in second shell. The photophysical properties of the phthalocyanine (Pc) complexes and their conjugates with SQDs are investigated in solution. Triplet quantum yields of complexes improved in the presence of semiconductor quantum dots. The optical limiting behaviour of the Pc complexes and conjugates are assessed using the open aperture Z–scan technique at laser excitation wavelength of 532 nm with 10 ns pulse. Pcs complexes showed good nonlinear optical response with higher nonlinear absorption coefficient. The conjugates afforded higher nonlinear absorption coefficient than Pc complexes alone.
- Full Text:
- Date Issued: 2019