Development of an enzyme-synergy based bioreactor system for the beneficiation of apple pomace lignocellulosic waste
- Authors: Abboo, Sagaran
- Date: 2016
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/315 , vital:19947
- Description: Due to the finite supply of non-renewable fossil fuels, agro-industrial wastes are identified as alternate, renewable sources for energy supply. Large amounts of fruit waste are generated in South Africa due to fruit juice and wine processing from apples, grapes and citrus fruit. Apple pomace is the solid residue that is left over after juice, cider and wine processing and constitutes between 25-30% of the total fruit. On a global scale millions of tonnes of apple pomace are produced; between 2006-2007 over 46 million tonnes were produced. In South Africa a total production of 244 469 tonnes were produced during the 2011- 2012 season. Initially, apple pomace was regarded as a waste by-product used for animal feed and compost in soil, however presently it is considered a source of dietary fiber and natural antioxidants like polyphenols. In addition, apple pomace has a high carbohydrate content and can be enzymatically hydrolysed to produce sugar monomers which, in turn, can be fermented by yeasts to produce bioethanol. The polyphenols present in apple pomace can be used for their health properties, and the bioethanol can be used as a replacement for fossil fuel. Apple pomace is lignocellulosic in nature and consists of hemicellulose, cellulose, lignin and pectin. A combination of enzymes such as cellulases, hemicellulases, pectinases and lignases are required to operate in synergy for the degradation of lignocellulosic biomass. This is due to the recalcitrant nature of lignocellulose. This study investigated the degradation of apple pomace using a combination of commercially obtained enzyme cocktails viz. Viscozyme L , Celluclast 1.5L and Novozyme 188. The commercial enzymes Viscozyme L and Celluclast 1.5L were added in a ratio of 1:1 (50%:50%). The final concentrations of the enzymes were 0.019 mg/ml each. Novozyme 188 was added to provide a final concentration of 0.0024 mg/ml. A novel cost effective 20L bioreactor was designed, constructed and implemented for the degradation of apple pomace to produce value added products. The hydrolysis of the apple pomace was performed initially in 1 L flasks (batch fed) and, once optimized, scaled up to a 20 L bioreactor in batch mode. The bioreactors were operated at room temperature (22 ± 2ºC) and in an unbuffered system. The sugars released were detected and quantified using an optimized validated HPLC method established in this study. The sugars released in the bioreactors were mainly glucose, galactose, arabinose, cellobiose and fructose. The polyphenols released in this study were gallic acid, catechin, epicatechin, chlorogenic acid, rutin and phloridzin, which have a number of health benefits. The simultaneous analyses of the polyphenols were performed using a newly developed and validated HPLC method established in this study. This method was developed to detect nine polyphenols simultaneously. The two HPLC methods developed and validated in this study for the analysis of sugars and polyphenols demonstrated good accuracy, precision, reproducibility, linearity, robustness and sensitivity. Both analytical methods were validated according to the International Convention on Harmonization (ICH). The HPLC parameters for sugar analysis were: refractive index (RI) as the detection mode, the stationary phase was a ligand-exchange sugar column (Shodex SP0810) and an aqueous mobile phase in isocratic mode was used. The HPLC method for polyphenols employed UV diode array detection (DAD) as the detection mode, a reverse phase column as the stationary phase and a mobile phase of consisting of 0.01 M phosphoric acid in water and 100% methanol using gradient elution mode. The highest concentrations of sugars released in the novel 20 L bioreactor with 20% apple pomace (w/v) substrate loading were as follow: glucose (6.5 mg/ml), followed by galactose (2.1 mg/ml), arabinose (1.4 mg/ml), cellobiose (0.7 mg/ml) and fructose (0.5 mg/ml). The amounts of polyphenols released at 20% (w/v) apple pomace substrate were epicatechin (0.01 mg/ml), catechin (0.002 mg/ml), rutin (0.03 mg/ml), chlorogenic acid (0.002 mg/ml) and gallic acid 0.01 (mg/ml). Two mathematical models were developed in this study for kinetic analysis of lignocellulose (apple pomace) hydrolysis in the novel 20 L bioreactor, using the experimental data generated by the above HPLC analyses. The first model, modelling with regression, defines the hydrolysis of the sugars glucose, galactose, cellobiose and arabinose produced in the novel 20 L bioreactor at 5%, 10%, 15% and 20% (w/v) substrate concentrations. The regression model describes the sugars produced in the 20 L bioreactor by minimizing the error of the sugars released by finding a value for K which minimises the function which computes the sum of squares of errors between the solution curves and the data points. The second, more complex, model developed in this study used a system of differential equations model (ODE). This model solved the system by using a numerical method, such as the Runge-Kutta method, then fitted the solution curves to the data. Both models simulated (and had the ability to predict) the production of sugars in the novel 20 L bioreactor for apple pomace hydrolysis. These two models also revealed the time at which the maximum amount of sugars were released, which revealed the optimum time to run the 20 L bioreactor in order to be more cost effective. The optimum time for maximum glucose (the main sugar used in fermentation for biofuel production) release was determined to be around 60 h. The ODE model, in addition, determined the rate at which the substrate became depleted, as well as the rate at which the enzymes became deactivated for the various substrate loadings in the 20 L bioreactor. A third model was developed to determine the optimal running cost of the bioreactor which incorporated the substrate loading and the amount of glucose (g/L) produced. The novel 20 L bioreactor constructed from cost effective materials demonstrated that agro-industrial waste can be converted to value-added products by lignocellolytic enzymes. The sugars released from apple pomace can be used in biofuel production and the polyphenols as food supplements and nutraceuticals for health benefits. This novel study contributes to agro-industrial waste beneficiation via fuel production. In addition, using agro-industrial waste for the generation of value added products (instead of mere disposal) will help prevent environmental pollution.
- Full Text:
- Date Issued: 2016
- Authors: Abboo, Sagaran
- Date: 2016
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/315 , vital:19947
- Description: Due to the finite supply of non-renewable fossil fuels, agro-industrial wastes are identified as alternate, renewable sources for energy supply. Large amounts of fruit waste are generated in South Africa due to fruit juice and wine processing from apples, grapes and citrus fruit. Apple pomace is the solid residue that is left over after juice, cider and wine processing and constitutes between 25-30% of the total fruit. On a global scale millions of tonnes of apple pomace are produced; between 2006-2007 over 46 million tonnes were produced. In South Africa a total production of 244 469 tonnes were produced during the 2011- 2012 season. Initially, apple pomace was regarded as a waste by-product used for animal feed and compost in soil, however presently it is considered a source of dietary fiber and natural antioxidants like polyphenols. In addition, apple pomace has a high carbohydrate content and can be enzymatically hydrolysed to produce sugar monomers which, in turn, can be fermented by yeasts to produce bioethanol. The polyphenols present in apple pomace can be used for their health properties, and the bioethanol can be used as a replacement for fossil fuel. Apple pomace is lignocellulosic in nature and consists of hemicellulose, cellulose, lignin and pectin. A combination of enzymes such as cellulases, hemicellulases, pectinases and lignases are required to operate in synergy for the degradation of lignocellulosic biomass. This is due to the recalcitrant nature of lignocellulose. This study investigated the degradation of apple pomace using a combination of commercially obtained enzyme cocktails viz. Viscozyme L , Celluclast 1.5L and Novozyme 188. The commercial enzymes Viscozyme L and Celluclast 1.5L were added in a ratio of 1:1 (50%:50%). The final concentrations of the enzymes were 0.019 mg/ml each. Novozyme 188 was added to provide a final concentration of 0.0024 mg/ml. A novel cost effective 20L bioreactor was designed, constructed and implemented for the degradation of apple pomace to produce value added products. The hydrolysis of the apple pomace was performed initially in 1 L flasks (batch fed) and, once optimized, scaled up to a 20 L bioreactor in batch mode. The bioreactors were operated at room temperature (22 ± 2ºC) and in an unbuffered system. The sugars released were detected and quantified using an optimized validated HPLC method established in this study. The sugars released in the bioreactors were mainly glucose, galactose, arabinose, cellobiose and fructose. The polyphenols released in this study were gallic acid, catechin, epicatechin, chlorogenic acid, rutin and phloridzin, which have a number of health benefits. The simultaneous analyses of the polyphenols were performed using a newly developed and validated HPLC method established in this study. This method was developed to detect nine polyphenols simultaneously. The two HPLC methods developed and validated in this study for the analysis of sugars and polyphenols demonstrated good accuracy, precision, reproducibility, linearity, robustness and sensitivity. Both analytical methods were validated according to the International Convention on Harmonization (ICH). The HPLC parameters for sugar analysis were: refractive index (RI) as the detection mode, the stationary phase was a ligand-exchange sugar column (Shodex SP0810) and an aqueous mobile phase in isocratic mode was used. The HPLC method for polyphenols employed UV diode array detection (DAD) as the detection mode, a reverse phase column as the stationary phase and a mobile phase of consisting of 0.01 M phosphoric acid in water and 100% methanol using gradient elution mode. The highest concentrations of sugars released in the novel 20 L bioreactor with 20% apple pomace (w/v) substrate loading were as follow: glucose (6.5 mg/ml), followed by galactose (2.1 mg/ml), arabinose (1.4 mg/ml), cellobiose (0.7 mg/ml) and fructose (0.5 mg/ml). The amounts of polyphenols released at 20% (w/v) apple pomace substrate were epicatechin (0.01 mg/ml), catechin (0.002 mg/ml), rutin (0.03 mg/ml), chlorogenic acid (0.002 mg/ml) and gallic acid 0.01 (mg/ml). Two mathematical models were developed in this study for kinetic analysis of lignocellulose (apple pomace) hydrolysis in the novel 20 L bioreactor, using the experimental data generated by the above HPLC analyses. The first model, modelling with regression, defines the hydrolysis of the sugars glucose, galactose, cellobiose and arabinose produced in the novel 20 L bioreactor at 5%, 10%, 15% and 20% (w/v) substrate concentrations. The regression model describes the sugars produced in the 20 L bioreactor by minimizing the error of the sugars released by finding a value for K which minimises the function which computes the sum of squares of errors between the solution curves and the data points. The second, more complex, model developed in this study used a system of differential equations model (ODE). This model solved the system by using a numerical method, such as the Runge-Kutta method, then fitted the solution curves to the data. Both models simulated (and had the ability to predict) the production of sugars in the novel 20 L bioreactor for apple pomace hydrolysis. These two models also revealed the time at which the maximum amount of sugars were released, which revealed the optimum time to run the 20 L bioreactor in order to be more cost effective. The optimum time for maximum glucose (the main sugar used in fermentation for biofuel production) release was determined to be around 60 h. The ODE model, in addition, determined the rate at which the substrate became depleted, as well as the rate at which the enzymes became deactivated for the various substrate loadings in the 20 L bioreactor. A third model was developed to determine the optimal running cost of the bioreactor which incorporated the substrate loading and the amount of glucose (g/L) produced. The novel 20 L bioreactor constructed from cost effective materials demonstrated that agro-industrial waste can be converted to value-added products by lignocellolytic enzymes. The sugars released from apple pomace can be used in biofuel production and the polyphenols as food supplements and nutraceuticals for health benefits. This novel study contributes to agro-industrial waste beneficiation via fuel production. In addition, using agro-industrial waste for the generation of value added products (instead of mere disposal) will help prevent environmental pollution.
- Full Text:
- Date Issued: 2016
Measuring the performance of the banking sector in Zimbabwe
- Authors: Abel, Sanderson
- Date: 2016
- Subjects: Banks and banking -- Zimbabwe , Bank profits -- Zimbabwe
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/5110 , vital:20806
- Description: The measurement of the banking sector performance in Zimbabwe is motivated by the unique developments that typified the sector during the period 2009-2014 after emerging from an economic crisis. The Zimbabwean economy returned to stability and growth in 2009, after a decade long economic decline. Economic stability brought about growth in deposits, loans, assets, capitalization and profits during this period. The banking sector has been accused of excessive profiteering through overpricing their products, which culminated in the intervention by the authorities in the sector. The interest rates spread, fees and other charges were presumed to be high which motivated the need to understand whether the banking sector is efficient or inefficient given the high interest rate spreads between the deposit rates and lending rates. Furthermore the high interest rates have raised the question of whether banks were exploiting their market power to price their products highly or whether their prices were determined by the dictates of market forces. Continued profitability of the sector also called for an investigation into what was driving the persistence of profitability over time. The primary objective of this research was to measure the performance of the banking sector during the period 2009-2014. The study contributes to the empirical literature by measuring and assessing the drivers of banking sector competition, efficiency and profitability and applying them at much disaggregated levels. This study also contributes to the debate on the relationships among the performance measures of competition, profitability and efficiency. The study adopted a number of methods which contributes to the array of tools central banks can employ to measure bank performance. The study employed a number of methodologies to measure the competition, efficiency and profitability performance of the banking sector. Competition was estimated using the new empirical industrial organisation methods of Panza and Rose (1987) and the Lerner (1934) Index was used. Cost and revenue efficiency was estimated using the two step methods of Data Envelopment Analysis followed by the Tobit regression method. An assessment of the persistence and drivers of profitability was measured using the Generalised Method of Moments. This study shows that the banking sector was operating under monopolistic competition market structure. This implies that banks held some market power as a result of product differentiation due to unique features such as brands, image and advertising, among others. The study indicates that competition increased during the period 2009-2014. Market power/competition in the banking sector during the study period was driven by capital adequacy, non-performing loans, liquidity risk, cost-income ratio, economic growth and government policy on pricing of bank products. The study suggests that the banking sector experienced an average inefficiency level of approximately 35 per cent in relationship with the best performing institutions in the sample. As a result of stability experienced in the economy, the average revenue and cost efficiency increased between 2009 and 2014. The study further established that the discord around the implementation of the indigenisation and empowerment law, coupled with the government intervention in the banking sector had a negative impact on the banking sector efficiency. It also found that efficiency is determined by market power, capital adequacy, cost income ratio, economic growth, inflation, market share and profitability. The Granger Causality test between cost efficiency and market power suggests that causality is bidirectional. On the other hand granger causality between revenue efficiency and market power is unidirectional and positive, running from revenue efficiency to market power. The result implies that policy measures should bring a balance between increasing competition and improving the revenue efficiency. The study shows that the banking sector was profitable during the period 2009 to 2014. The profitability was a reflection of a stable macroeconomic environment, typified by low inflation levels, despite the crises during this period. It further reveals that the banking sector‟s profitability persisted over time, reflecting the regulatory structure of the sector. The study established that profitability was determined by market power, non-performing loans, liquidity risk, capital adequacy, bank size and cost efficiency. This implies profitability was driven by bank specific determinants. There are a number of policy implications derived from the study. Regulatory measures such as forced consolidations can lead to excessive market power by the banking institution; hence it should be moderated. Banks should enhance credit risk because NPLs has been dragging profits. Banks should take advantage of the various measures introduced, such as the setting up of the special purpose vehicle and credit reference bureau. The government should avoid tampering with market forces as this reduces competition, efficiency and profitability and put in place measures that grow the economy as it increases the efficiency and profitability of the banking sector.
- Full Text:
- Date Issued: 2016
- Authors: Abel, Sanderson
- Date: 2016
- Subjects: Banks and banking -- Zimbabwe , Bank profits -- Zimbabwe
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/5110 , vital:20806
- Description: The measurement of the banking sector performance in Zimbabwe is motivated by the unique developments that typified the sector during the period 2009-2014 after emerging from an economic crisis. The Zimbabwean economy returned to stability and growth in 2009, after a decade long economic decline. Economic stability brought about growth in deposits, loans, assets, capitalization and profits during this period. The banking sector has been accused of excessive profiteering through overpricing their products, which culminated in the intervention by the authorities in the sector. The interest rates spread, fees and other charges were presumed to be high which motivated the need to understand whether the banking sector is efficient or inefficient given the high interest rate spreads between the deposit rates and lending rates. Furthermore the high interest rates have raised the question of whether banks were exploiting their market power to price their products highly or whether their prices were determined by the dictates of market forces. Continued profitability of the sector also called for an investigation into what was driving the persistence of profitability over time. The primary objective of this research was to measure the performance of the banking sector during the period 2009-2014. The study contributes to the empirical literature by measuring and assessing the drivers of banking sector competition, efficiency and profitability and applying them at much disaggregated levels. This study also contributes to the debate on the relationships among the performance measures of competition, profitability and efficiency. The study adopted a number of methods which contributes to the array of tools central banks can employ to measure bank performance. The study employed a number of methodologies to measure the competition, efficiency and profitability performance of the banking sector. Competition was estimated using the new empirical industrial organisation methods of Panza and Rose (1987) and the Lerner (1934) Index was used. Cost and revenue efficiency was estimated using the two step methods of Data Envelopment Analysis followed by the Tobit regression method. An assessment of the persistence and drivers of profitability was measured using the Generalised Method of Moments. This study shows that the banking sector was operating under monopolistic competition market structure. This implies that banks held some market power as a result of product differentiation due to unique features such as brands, image and advertising, among others. The study indicates that competition increased during the period 2009-2014. Market power/competition in the banking sector during the study period was driven by capital adequacy, non-performing loans, liquidity risk, cost-income ratio, economic growth and government policy on pricing of bank products. The study suggests that the banking sector experienced an average inefficiency level of approximately 35 per cent in relationship with the best performing institutions in the sample. As a result of stability experienced in the economy, the average revenue and cost efficiency increased between 2009 and 2014. The study further established that the discord around the implementation of the indigenisation and empowerment law, coupled with the government intervention in the banking sector had a negative impact on the banking sector efficiency. It also found that efficiency is determined by market power, capital adequacy, cost income ratio, economic growth, inflation, market share and profitability. The Granger Causality test between cost efficiency and market power suggests that causality is bidirectional. On the other hand granger causality between revenue efficiency and market power is unidirectional and positive, running from revenue efficiency to market power. The result implies that policy measures should bring a balance between increasing competition and improving the revenue efficiency. The study shows that the banking sector was profitable during the period 2009 to 2014. The profitability was a reflection of a stable macroeconomic environment, typified by low inflation levels, despite the crises during this period. It further reveals that the banking sector‟s profitability persisted over time, reflecting the regulatory structure of the sector. The study established that profitability was determined by market power, non-performing loans, liquidity risk, capital adequacy, bank size and cost efficiency. This implies profitability was driven by bank specific determinants. There are a number of policy implications derived from the study. Regulatory measures such as forced consolidations can lead to excessive market power by the banking institution; hence it should be moderated. Banks should enhance credit risk because NPLs has been dragging profits. Banks should take advantage of the various measures introduced, such as the setting up of the special purpose vehicle and credit reference bureau. The government should avoid tampering with market forces as this reduces competition, efficiency and profitability and put in place measures that grow the economy as it increases the efficiency and profitability of the banking sector.
- Full Text:
- Date Issued: 2016
Graphene quantum dots functionalized with 4-amino-2, 2, 6, 6-tetramethylpiperidine-N-oxide as fluorescence “turn-on” nanosensors
- Achadu, Ojodomo J, Britton, Jonathan, Nyokong, Tebello
- Authors: Achadu, Ojodomo J , Britton, Jonathan , Nyokong, Tebello
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/239854 , vital:50773 , xlink:href="https://doi.org/10.1007/s10895-016-1916-y"
- Description: In this study, we report on the fabrication of simple and rapid graphene quantum dots (GQDs)-based fluorescence “turn-ON” nanoprobes for sensitive and selective detection of ascorbic acid (AA). Pristine GQDs and S and N co-doped-GQDs (SN-GQDs) were functionalized with 4-amino-2,2,6,6-tetramethylpiperidine-N-oxide (4-amino-TEMPO, a nitroxide free radical). The nitroxide free radicals efficiently quenched the fluorescence of the GQDs and upon interaction of the nanoconjugates with ascorbic acid, the quenched fluorescence was restored. The linear ranges recorded were 0.5–5.7 μM and 0.1–5.5 μM for GQDs-4-amino-TEMPO and SN-GQDs-4amino-TEMPO nanoprobes, respectively. Limits of detection were found to be 60 nM and 84 nM for SN-GQDS-4-amino-TEMPO and GQDs-4-amino-TEMPO for AA detection, respectively. This novel fluorescence “turn-ON” technique showed to be highly rapid and selective towards AA detection.
- Full Text:
- Date Issued: 2016
- Authors: Achadu, Ojodomo J , Britton, Jonathan , Nyokong, Tebello
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/239854 , vital:50773 , xlink:href="https://doi.org/10.1007/s10895-016-1916-y"
- Description: In this study, we report on the fabrication of simple and rapid graphene quantum dots (GQDs)-based fluorescence “turn-ON” nanoprobes for sensitive and selective detection of ascorbic acid (AA). Pristine GQDs and S and N co-doped-GQDs (SN-GQDs) were functionalized with 4-amino-2,2,6,6-tetramethylpiperidine-N-oxide (4-amino-TEMPO, a nitroxide free radical). The nitroxide free radicals efficiently quenched the fluorescence of the GQDs and upon interaction of the nanoconjugates with ascorbic acid, the quenched fluorescence was restored. The linear ranges recorded were 0.5–5.7 μM and 0.1–5.5 μM for GQDs-4-amino-TEMPO and SN-GQDs-4amino-TEMPO nanoprobes, respectively. Limits of detection were found to be 60 nM and 84 nM for SN-GQDS-4-amino-TEMPO and GQDs-4-amino-TEMPO for AA detection, respectively. This novel fluorescence “turn-ON” technique showed to be highly rapid and selective towards AA detection.
- Full Text:
- Date Issued: 2016
Interaction of graphene quantum dots with 4-acetamido-2, 2, 6, 6-tetramethylpiperidine-oxyl free radicals
- Achadu, Ojodomo John, Nyokong, Tebello
- Authors: Achadu, Ojodomo John , Nyokong, Tebello
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/189031 , vital:44810 , xlink:href="https://doi.org/10.1007/s10895-015-1712-0"
- Description: We report on the interaction of graphene quantum dots (GQDs) with 4-acetamido-2,2,6,6-tetramethylpiperidineoxyl (4-acetamido-TEMPO) free radicals. The GQDs were N and S, N doped. The fluorescence quantum yields were higher for the doped GQDs compared to the undoped. The interaction is assessed by spectrofluorimetric, steady state/time resolved fluorescence and electron paramagnetic resonance (EPR) techniques. Fluorescence quenching was observed upon the addition of 4-acetamido-TEMPO to the GQDs. Photoinduced electron transfer (PET) mechanism was suggested as the plausible mechanism involved in the fluorescence quenching in which 4-acetamido-TEMPO acted as the electron acceptor.
- Full Text:
- Date Issued: 2016
- Authors: Achadu, Ojodomo John , Nyokong, Tebello
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/189031 , vital:44810 , xlink:href="https://doi.org/10.1007/s10895-015-1712-0"
- Description: We report on the interaction of graphene quantum dots (GQDs) with 4-acetamido-2,2,6,6-tetramethylpiperidineoxyl (4-acetamido-TEMPO) free radicals. The GQDs were N and S, N doped. The fluorescence quantum yields were higher for the doped GQDs compared to the undoped. The interaction is assessed by spectrofluorimetric, steady state/time resolved fluorescence and electron paramagnetic resonance (EPR) techniques. Fluorescence quenching was observed upon the addition of 4-acetamido-TEMPO to the GQDs. Photoinduced electron transfer (PET) mechanism was suggested as the plausible mechanism involved in the fluorescence quenching in which 4-acetamido-TEMPO acted as the electron acceptor.
- Full Text:
- Date Issued: 2016
The interaction between graphene quantum dots grafted with polyethyleneimine and Au@ Ag nanoparticles
- Achadu, Ojodomo John, Uddin, Imran, Nyokong, Tebello
- Authors: Achadu, Ojodomo John , Uddin, Imran , Nyokong, Tebello
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/188679 , vital:44775 , xlink:href="https://doi.org/10.1016/j.jphotochem.2016.03.016"
- Description: Graphene quantum dots grafted with polyethyleneimine (GQDs-PEI) and Au@Ag core-shell nanoparticles blend was demonstrated to be a novel biosensing nanoprobe for the rapid and highly sensitive detection of biothiols such as cysteine (Cys), homocysteine (Hcys) and glutathione (GSH). The fluorescence emission of GQDs-PEI was quenched efficiently upon interaction with Au@Ag core-shell nanoparticles. The quenched fluorescence emission of the GQDs-PEI was restored in the presence of the biothiols. The fluorimetric sensing is based on the strong affinity between the mercapto (SH) groups of the biothiols and the Au@Ag core-shell nanoparticles by which the interaction between GQDs-PEI and Au@Ag core-shell nanoparticles was disrupted with a consequent modulation (‘turn-on’) of the quenched GQDs-PEI emission. Thus, a new, simple, rapid and highly sensitive fluorescence nanoprobe for detecting biothiols has been developed in this work.
- Full Text:
- Date Issued: 2016
- Authors: Achadu, Ojodomo John , Uddin, Imran , Nyokong, Tebello
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/188679 , vital:44775 , xlink:href="https://doi.org/10.1016/j.jphotochem.2016.03.016"
- Description: Graphene quantum dots grafted with polyethyleneimine (GQDs-PEI) and Au@Ag core-shell nanoparticles blend was demonstrated to be a novel biosensing nanoprobe for the rapid and highly sensitive detection of biothiols such as cysteine (Cys), homocysteine (Hcys) and glutathione (GSH). The fluorescence emission of GQDs-PEI was quenched efficiently upon interaction with Au@Ag core-shell nanoparticles. The quenched fluorescence emission of the GQDs-PEI was restored in the presence of the biothiols. The fluorimetric sensing is based on the strong affinity between the mercapto (SH) groups of the biothiols and the Au@Ag core-shell nanoparticles by which the interaction between GQDs-PEI and Au@Ag core-shell nanoparticles was disrupted with a consequent modulation (‘turn-on’) of the quenched GQDs-PEI emission. Thus, a new, simple, rapid and highly sensitive fluorescence nanoprobe for detecting biothiols has been developed in this work.
- Full Text:
- Date Issued: 2016
Fluorescence behavior of nanoconjugates of graphene quantum dots and zinc phthalocyanines
- Achadu, Ojodomo John, Uddin, Imran, Nyokong, Tebello
- Authors: Achadu, Ojodomo John , Uddin, Imran , Nyokong, Tebello
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/188777 , vital:44784 , xlink:href="https://doi.org/10.1016/j.jphotochem.2015.11.006"
- Description: Graphene quantum dots (GQDs) and zinc phthalocyanines interactions in different modes (covalent and non-covalent) are reported in this study. GQDs were covalently attached to the following complexes: zinc tetraamino phthalocyanine (ZnTAPc) via amide coupling, zinc tetracarboxyphenoxy Pc (ZnTCPPc) (π–π interaction) and cationic zinc tetrapyridiloxy Pc (ZnTmPyPc) (ionic interaction). GQDs fluorescence was quenched in the presence of the ZnPc derivatives. The nanoensembles of GQDs–ZnPcs showed stimulated emissions of the ZnPcs. The suggested quenching mechanism is through Förster resonance energy transfer (FRET). These novel nanoensembles hold promise for various optical and luminescence based applications.
- Full Text:
- Date Issued: 2016
- Authors: Achadu, Ojodomo John , Uddin, Imran , Nyokong, Tebello
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/188777 , vital:44784 , xlink:href="https://doi.org/10.1016/j.jphotochem.2015.11.006"
- Description: Graphene quantum dots (GQDs) and zinc phthalocyanines interactions in different modes (covalent and non-covalent) are reported in this study. GQDs were covalently attached to the following complexes: zinc tetraamino phthalocyanine (ZnTAPc) via amide coupling, zinc tetracarboxyphenoxy Pc (ZnTCPPc) (π–π interaction) and cationic zinc tetrapyridiloxy Pc (ZnTmPyPc) (ionic interaction). GQDs fluorescence was quenched in the presence of the ZnPc derivatives. The nanoensembles of GQDs–ZnPcs showed stimulated emissions of the ZnPcs. The suggested quenching mechanism is through Förster resonance energy transfer (FRET). These novel nanoensembles hold promise for various optical and luminescence based applications.
- Full Text:
- Date Issued: 2016
The personal financial management attitudes and practices of South African rugby players
- Authors: Acker, Enrico
- Date: 2016
- Subjects: Rugby football players -- South Africa -- Finance, Personal Finance, Personal -- South Africa
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: http://hdl.handle.net/10948/11363 , vital:26915
- Description: When rugby became professional in 1995, both the game and the social and financial position of the players changed (Basson, 2003). Players started to train full-time and earned annual salaries (Goldman& Johns, 2009). Due to the transition from amateur to professional status, rugby players needed to make adequate personal financial management decisions. The purpose of this study is to investigate the personal financial management attitudes and practices of South African rugby players. Previous research about personal financial management largely focussed on the general public, and did not focus on South African rugby players. Rugby is a professional sport where players earn money from a young age. It is expected of rugby players to make adequate personal financial decisions from as early as 19 years old. The literature review provided an overview of personal financial management and a discussion on the various components that should be included in personal financial management. A framework for this study was developed. The framework used these components as the base for the personal financial attitudes and practices and how it relates to the demographics of the respondents. Three hypotheses were also formulated based on the literature overview and framework. The objectives of this study were achieved by adopting a quantitative research methodology. A convenience sample of 132 rugby players was drawn for this study. Rugby players from NMMU Madibaz, Eastern Province Rugby Union (EP), South Western Districts Rugby Union (SWD) and Sharks Rugby Union participated in this study. The results of the empirical survey showed that respondents have positive attitudes towards the importance of budgeting, retirement planning, risk management, debt management and investment and the importance of employing a financial planner. On the other hand the personal financial management practices of the respondents in this study can be described as weak. From the results of the empirical survey it is clear that the respondents have weak practices towards the majority of the personal financial management practices. Only one of the three hypotheses was accepted namely that there is a relationship between the demographics of rugby players and their personal financial practices. There is no relationship between personal financial management attitudes and personal financial management practices of South African rugby players and that there is also no relationship between demographic variables and personal financial management attitudes of South African rugby players. This study has provided insight into the personal financial management attitudes and practices of South African rugby players. Valuable information was obtained that could help to address the personal financial management needs of rugby players.
- Full Text:
- Date Issued: 2016
- Authors: Acker, Enrico
- Date: 2016
- Subjects: Rugby football players -- South Africa -- Finance, Personal Finance, Personal -- South Africa
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: http://hdl.handle.net/10948/11363 , vital:26915
- Description: When rugby became professional in 1995, both the game and the social and financial position of the players changed (Basson, 2003). Players started to train full-time and earned annual salaries (Goldman& Johns, 2009). Due to the transition from amateur to professional status, rugby players needed to make adequate personal financial management decisions. The purpose of this study is to investigate the personal financial management attitudes and practices of South African rugby players. Previous research about personal financial management largely focussed on the general public, and did not focus on South African rugby players. Rugby is a professional sport where players earn money from a young age. It is expected of rugby players to make adequate personal financial decisions from as early as 19 years old. The literature review provided an overview of personal financial management and a discussion on the various components that should be included in personal financial management. A framework for this study was developed. The framework used these components as the base for the personal financial attitudes and practices and how it relates to the demographics of the respondents. Three hypotheses were also formulated based on the literature overview and framework. The objectives of this study were achieved by adopting a quantitative research methodology. A convenience sample of 132 rugby players was drawn for this study. Rugby players from NMMU Madibaz, Eastern Province Rugby Union (EP), South Western Districts Rugby Union (SWD) and Sharks Rugby Union participated in this study. The results of the empirical survey showed that respondents have positive attitudes towards the importance of budgeting, retirement planning, risk management, debt management and investment and the importance of employing a financial planner. On the other hand the personal financial management practices of the respondents in this study can be described as weak. From the results of the empirical survey it is clear that the respondents have weak practices towards the majority of the personal financial management practices. Only one of the three hypotheses was accepted namely that there is a relationship between the demographics of rugby players and their personal financial practices. There is no relationship between personal financial management attitudes and personal financial management practices of South African rugby players and that there is also no relationship between demographic variables and personal financial management attitudes of South African rugby players. This study has provided insight into the personal financial management attitudes and practices of South African rugby players. Valuable information was obtained that could help to address the personal financial management needs of rugby players.
- Full Text:
- Date Issued: 2016
Distribution and use of cash income from basket and mat crafting: Implications for rural livelihoods in the Eastern Cape, South Africa
- Adam, Y O, Shackleton, Charlie M
- Authors: Adam, Y O , Shackleton, Charlie M
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/180434 , vital:43388 , xlink:href="https://doi.org/10.1080/14728028.2016.1186576"
- Description: The objective of this paper was to investigate the extent to which baskets and mats local trade contributes to rural livelihoods of the crafters’ household and community downstream income. Primary data were collected through structured interviews with 83 crafters from Noqhekwana village in Port St. Johns municipality using snowball sampling in May, 2015. The survey was supplemented by secondary data and direct observations. The findings show that crafting contributed 35% of crafter’s household total income. The received income is spent on expenses in the household and downstream actors depending on the crafter’s priorities. Lack of organization between crafters, access to sufficient raw material, and low prices were identified as major challenges involved in the production and trade of the products.
- Full Text:
- Date Issued: 2016
- Authors: Adam, Y O , Shackleton, Charlie M
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/180434 , vital:43388 , xlink:href="https://doi.org/10.1080/14728028.2016.1186576"
- Description: The objective of this paper was to investigate the extent to which baskets and mats local trade contributes to rural livelihoods of the crafters’ household and community downstream income. Primary data were collected through structured interviews with 83 crafters from Noqhekwana village in Port St. Johns municipality using snowball sampling in May, 2015. The survey was supplemented by secondary data and direct observations. The findings show that crafting contributed 35% of crafter’s household total income. The received income is spent on expenses in the household and downstream actors depending on the crafter’s priorities. Lack of organization between crafters, access to sufficient raw material, and low prices were identified as major challenges involved in the production and trade of the products.
- Full Text:
- Date Issued: 2016
Fathers' involvement in the social development of children under six years: a social capital perspective and implications for early childhood development in the East London Education District
- Authors: Adams, Clyde Glenith Graham
- Date: 2016
- Subjects: Child development-- South Africa -- Eastern Cape Father and child -- South Africa -- Eastern Cape Fatherhood -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , Degree
- Identifier: http://hdl.handle.net/10353/5116 , vital:29077
- Description: The experiences of twenty fathers were explored to understand the involvement in the social development of children under six years. The main research question that guided the study was: what are fathers’ experiences with involvement in the social development of their children under the age of six years and what implications do these have for early childhood development? A social capital perspective was followed. The qualitative data was collected through the use of semi-structured interviews. The data was then analysed qualitatively. Results show that although most of the respondents could not give a definition of the concept of social development, they, however, understood the importance of parents playing a role in the development of a child. Fathers understood their role as supportive, nurturing and being there for their children. Fathers also understood their basic role as being the provider and protector. They also perceived their role as being authoritative and see themselves as the main disciplinarians. Results reveal that most schools do not offer programs specifically designed to encourage fathers to participate. Most importantly, results indicate that fathers’ interest in a variety of sporting activities, information sharing and talking about challenges both the schools as well as fathers face, are some of the ways fathers would like to be involved. Findings also indicate that although fathers acknowledged the role of the Department of Basic Education (DoBE) as mainly that of financial contributor in order to facilitate the skills development as well as that of information dissemination. However, fathers who took part in the study did not understand how the DoBE skills development agenda is envisaged for fathers. Notwithstanding, the respondents were quite clear that a father has an influential role to play in their children’s development. It also emerged that the greater the involvement, the more positive the influence on the child’s development. This study concludes that the presence of fathers in children’s lives is known to contribute significantly to their chances of experiencing positive developmental outcomes. Although the father-child relationship’s influences on children’s social competence have received increased attention in general, research on fathers’ understanding of their roles, involvement with their children as well as challenges confronting them with their involvement is scant. Based this the above, a number of recommendations have been made.
- Full Text:
- Date Issued: 2016
- Authors: Adams, Clyde Glenith Graham
- Date: 2016
- Subjects: Child development-- South Africa -- Eastern Cape Father and child -- South Africa -- Eastern Cape Fatherhood -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , Degree
- Identifier: http://hdl.handle.net/10353/5116 , vital:29077
- Description: The experiences of twenty fathers were explored to understand the involvement in the social development of children under six years. The main research question that guided the study was: what are fathers’ experiences with involvement in the social development of their children under the age of six years and what implications do these have for early childhood development? A social capital perspective was followed. The qualitative data was collected through the use of semi-structured interviews. The data was then analysed qualitatively. Results show that although most of the respondents could not give a definition of the concept of social development, they, however, understood the importance of parents playing a role in the development of a child. Fathers understood their role as supportive, nurturing and being there for their children. Fathers also understood their basic role as being the provider and protector. They also perceived their role as being authoritative and see themselves as the main disciplinarians. Results reveal that most schools do not offer programs specifically designed to encourage fathers to participate. Most importantly, results indicate that fathers’ interest in a variety of sporting activities, information sharing and talking about challenges both the schools as well as fathers face, are some of the ways fathers would like to be involved. Findings also indicate that although fathers acknowledged the role of the Department of Basic Education (DoBE) as mainly that of financial contributor in order to facilitate the skills development as well as that of information dissemination. However, fathers who took part in the study did not understand how the DoBE skills development agenda is envisaged for fathers. Notwithstanding, the respondents were quite clear that a father has an influential role to play in their children’s development. It also emerged that the greater the involvement, the more positive the influence on the child’s development. This study concludes that the presence of fathers in children’s lives is known to contribute significantly to their chances of experiencing positive developmental outcomes. Although the father-child relationship’s influences on children’s social competence have received increased attention in general, research on fathers’ understanding of their roles, involvement with their children as well as challenges confronting them with their involvement is scant. Based this the above, a number of recommendations have been made.
- Full Text:
- Date Issued: 2016
An international marketing framework for Ford South Africa in Nigeria
- Authors: Adams, Pedro Duan
- Date: 2016
- Subjects: Export marketing -- Cross-cultural studies , Marketing -- Cross-cultural studies , Marketing -- Management -- Cross-cultural studies
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: http://hdl.handle.net/10948/3869 , vital:20471
- Description: Africa is seen as the last investment frontier and according to literature will have a GDP of $1.5 trillion by the year 2016 and a population that is double the size of Europe. The rapid expansion of infrastructure and construction in African countries, such as Mozambique and Zambia has increased the demand for commercial vehicles. This has sparked unparalleled marketing opportunities for automotive manufacturers and the continent is fast attracting major players in this sector. The international marketing literature still lacks detailed studies and research into the marketing deliberations and trades in Africa. Therefore, according literature a greater representation of African culture within the international marketing literature would provide relevance and richness in the global market place and offer greater insight to organisations who are seeking to invest and expand their businesses in Africa. The management issue here is to comprehend the diversity and vastness of this region and putting together all spheres to ensure growth and creating brand loyalty. The key challenge here is for management to be able to grasp and understand not only the various cultures but also the way of doing business in such a vastly different region. It is therefore imperative for Ford Motor Company to fully understand these factors so as to take full advantage associated with entering a market early which is commonly referred as first-mover-advantage. A case in point is when General Motors entered the Chinese automotive industry in 1997 when the Chinese market was relatively small. General Motors’ enthusiasm and commitment back in 1997 was driven by a belief that China would ultimately become an economic powerhouse and emerge as one of the world’s largest automotive markets. By the year 2010 China was one of the world’s biggest automotive markets and General Motors was a dominant force in this market. Africa has all the key elements for the growth and development of a robust automotive market. By studying past experiences and outcomes from empirical studies on international marketing with emphasis on the automotive industry, it will be possible to draw lessons and experience about the potential growth of the automotive sector on the African continent. This study will also be of great significance to other automotive manufacturers and suppliers looking to expand their business and market share across Africa due to the increase of the middle class. Therefore creative strategies and thinking of how to circumvent challenges in the African cultural environment, creativity in managing bureaucracy and due diligence about business and investment opportunities will uncover unprecedented volumes of profitable business that lies untapped on the African continent. Data from the quantitative study suggest that culture, political environment, country-of-origin, competition and country infrastructure in Nigeria, are essential factors to the development of a successful international marketing strategy for Ford South Africa. This study therefore concludes that Ford Motor Company of South Africa can utilize this framework in order to gain greater market share and ultimately success in Nigeria. Recommendations were also made for future research studies that can contribute to the international marketing literature with emphasis on the African market.
- Full Text:
- Date Issued: 2016
- Authors: Adams, Pedro Duan
- Date: 2016
- Subjects: Export marketing -- Cross-cultural studies , Marketing -- Cross-cultural studies , Marketing -- Management -- Cross-cultural studies
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: http://hdl.handle.net/10948/3869 , vital:20471
- Description: Africa is seen as the last investment frontier and according to literature will have a GDP of $1.5 trillion by the year 2016 and a population that is double the size of Europe. The rapid expansion of infrastructure and construction in African countries, such as Mozambique and Zambia has increased the demand for commercial vehicles. This has sparked unparalleled marketing opportunities for automotive manufacturers and the continent is fast attracting major players in this sector. The international marketing literature still lacks detailed studies and research into the marketing deliberations and trades in Africa. Therefore, according literature a greater representation of African culture within the international marketing literature would provide relevance and richness in the global market place and offer greater insight to organisations who are seeking to invest and expand their businesses in Africa. The management issue here is to comprehend the diversity and vastness of this region and putting together all spheres to ensure growth and creating brand loyalty. The key challenge here is for management to be able to grasp and understand not only the various cultures but also the way of doing business in such a vastly different region. It is therefore imperative for Ford Motor Company to fully understand these factors so as to take full advantage associated with entering a market early which is commonly referred as first-mover-advantage. A case in point is when General Motors entered the Chinese automotive industry in 1997 when the Chinese market was relatively small. General Motors’ enthusiasm and commitment back in 1997 was driven by a belief that China would ultimately become an economic powerhouse and emerge as one of the world’s largest automotive markets. By the year 2010 China was one of the world’s biggest automotive markets and General Motors was a dominant force in this market. Africa has all the key elements for the growth and development of a robust automotive market. By studying past experiences and outcomes from empirical studies on international marketing with emphasis on the automotive industry, it will be possible to draw lessons and experience about the potential growth of the automotive sector on the African continent. This study will also be of great significance to other automotive manufacturers and suppliers looking to expand their business and market share across Africa due to the increase of the middle class. Therefore creative strategies and thinking of how to circumvent challenges in the African cultural environment, creativity in managing bureaucracy and due diligence about business and investment opportunities will uncover unprecedented volumes of profitable business that lies untapped on the African continent. Data from the quantitative study suggest that culture, political environment, country-of-origin, competition and country infrastructure in Nigeria, are essential factors to the development of a successful international marketing strategy for Ford South Africa. This study therefore concludes that Ford Motor Company of South Africa can utilize this framework in order to gain greater market share and ultimately success in Nigeria. Recommendations were also made for future research studies that can contribute to the international marketing literature with emphasis on the African market.
- Full Text:
- Date Issued: 2016
Evaluation of the incidence of enteric viruses, Vibrio species and Escherichia coli pathotypes in effluents of two wastewater treatment plants located in Keiskammahoek and Stutterheim in the Eastern Cape Province of South Africa
- Authors: Adefisoye, Martins Ajibade
- Date: 2016
- Subjects: Escherichia coli -- South Africa -- Eastern Cape Water -- Purification -- South Africa -- Eastern Cape Effluent quality -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10353/3165 , vital:28328
- Description: South Africa is currently experiencing water shortage crisis, a challenge that has been attributed not only to the scarcity of freshwater, but also to fast degrading water quality. Factors such as rapid urbanisation, population and economic growth, climate change as well as poor operational and maintenance of many of the exisiting water/wastewater treatment facilities have been acknowledged as important contributors to degrading water quality in the country. Untreated or inadequately treated discharged wastewater effluents constitute point source pollution to many freshwater environments in South Africa. Hence, it becomes imperative to evaluate wastewater discharges in other to protect the scarce freshwater resource, the environment and public health. Over a twelve-month sampling period (September 2012 to August 2013), we assessed the bacteriological, virological and physicochemical qualities of the discharged final effluents of two wastewater treatment facilities in the Eastern Cape Province of South Africa. For the physicochemical assessment, a total of 144 final effluent samples were collected from both the final effluent tanks (FE) and the discharge points (DP) of the treatment facilities. Physicochemical parameters including pH, temperature, turbidity, total dissolved solids (TDS), dissolved oxygen (DO), electrical conductivity (EC) and free chlorine concentration were determined on site while biological oxygen demand (BOD), nitrate (NO3-), nitrite (NO2-), phosphate (PO4-) and chemical oxygen demand (COD) were determined in the laboratory. The bacteriological analysis of the samples was done using standard membrane filtration (MF) technique. Bacterial group assessed included: faecal indicator bacteria (faecal coliforms and E. coli) and Vibrio species, while the antibiotic susceptibility profiles of selected E. coli and Vibrio species isolates against some selected antibiotics commonly used in human therapy and veterinary medicine were determind using the standard agar-disc diffusion method. The occurrence and concentrations of human enteric viruses including: human adenovirus (HAdV), hepatitis A virus (HAV) and rotavirus (RoV) in the samples were determined by TaqMan-based real-time polymerase chain reaction (qPCR) following concentration by adsorption-elution method. The physicochemical characteristics of the samples ranged as follows: pH (6.5 – 7.6), TDS (95 – 171 mg/L), EC (134 – 267 μS/cm), temperature (12 – 27 °C), turbidity (1.5 – 65.7 mg/L), free chlorine (0.08 – 0.72 mg/L), DO (2.06 – 9.81 mg/L), BOD (0.13 – 9.81 mg/L), NO3- (0 – 21.5 mg/L), NO2- (0 – 0.72 mg/L), PO4- (0 – 18.3 mg/L) and COD (27 – 680 mg/L). Some of the characteristic such as pH, TDS, EC, temperature, nitrite and DO (on most instances) complied with recommended guidelines. Other characteristics, however, including turbidity, BOD, nitrate, phosphate and COD fell short of the recommended guidelines. All the 48 samples analysed for bacteriological qualities tested positive for the presence of the bacterial groups with significant (P≤0.05) seasonal variation in their densities. Faecal coliforms were detected in counts ranging from 1 CFU/100ml to 2.7 × 104 CFU/100ml. Presumptive E. coli counts ranged generally between 1 CFU/100ml – 1.4 × 105 CFU/100ml while counts of presumptive Vibrio species ranged between 4 CFU/100ml – 1.4 × 104 CFU/100ml. Molecular identification of the presumptive isolates by polymerase chain reactions PCR gave positive reaction rates of 76.2 percent (381/500) and 69.8 percent (279/400) for E.coli and Vibrio species respectively. The antibiotic susceptibility profiling of 205 PCR-confirmed Vibiro isolates against 18 commomly used antibiotics showed resistance frequencies ranging from 0.5 percent (imipenem) to 96.1 percent (penicillin G) at recommended breakpoint concentrations. Eighty-one percent (166/205) of the Vibrio isolates showed multidrug resistance (resistance to 3 or more antibiotics) with the most common multiple antibiotic resistance phenotype (MARP) being AP-T-TM-SMX-PG-NI-PB, occurring in 8 isolates.
- Full Text:
- Date Issued: 2016
- Authors: Adefisoye, Martins Ajibade
- Date: 2016
- Subjects: Escherichia coli -- South Africa -- Eastern Cape Water -- Purification -- South Africa -- Eastern Cape Effluent quality -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10353/3165 , vital:28328
- Description: South Africa is currently experiencing water shortage crisis, a challenge that has been attributed not only to the scarcity of freshwater, but also to fast degrading water quality. Factors such as rapid urbanisation, population and economic growth, climate change as well as poor operational and maintenance of many of the exisiting water/wastewater treatment facilities have been acknowledged as important contributors to degrading water quality in the country. Untreated or inadequately treated discharged wastewater effluents constitute point source pollution to many freshwater environments in South Africa. Hence, it becomes imperative to evaluate wastewater discharges in other to protect the scarce freshwater resource, the environment and public health. Over a twelve-month sampling period (September 2012 to August 2013), we assessed the bacteriological, virological and physicochemical qualities of the discharged final effluents of two wastewater treatment facilities in the Eastern Cape Province of South Africa. For the physicochemical assessment, a total of 144 final effluent samples were collected from both the final effluent tanks (FE) and the discharge points (DP) of the treatment facilities. Physicochemical parameters including pH, temperature, turbidity, total dissolved solids (TDS), dissolved oxygen (DO), electrical conductivity (EC) and free chlorine concentration were determined on site while biological oxygen demand (BOD), nitrate (NO3-), nitrite (NO2-), phosphate (PO4-) and chemical oxygen demand (COD) were determined in the laboratory. The bacteriological analysis of the samples was done using standard membrane filtration (MF) technique. Bacterial group assessed included: faecal indicator bacteria (faecal coliforms and E. coli) and Vibrio species, while the antibiotic susceptibility profiles of selected E. coli and Vibrio species isolates against some selected antibiotics commonly used in human therapy and veterinary medicine were determind using the standard agar-disc diffusion method. The occurrence and concentrations of human enteric viruses including: human adenovirus (HAdV), hepatitis A virus (HAV) and rotavirus (RoV) in the samples were determined by TaqMan-based real-time polymerase chain reaction (qPCR) following concentration by adsorption-elution method. The physicochemical characteristics of the samples ranged as follows: pH (6.5 – 7.6), TDS (95 – 171 mg/L), EC (134 – 267 μS/cm), temperature (12 – 27 °C), turbidity (1.5 – 65.7 mg/L), free chlorine (0.08 – 0.72 mg/L), DO (2.06 – 9.81 mg/L), BOD (0.13 – 9.81 mg/L), NO3- (0 – 21.5 mg/L), NO2- (0 – 0.72 mg/L), PO4- (0 – 18.3 mg/L) and COD (27 – 680 mg/L). Some of the characteristic such as pH, TDS, EC, temperature, nitrite and DO (on most instances) complied with recommended guidelines. Other characteristics, however, including turbidity, BOD, nitrate, phosphate and COD fell short of the recommended guidelines. All the 48 samples analysed for bacteriological qualities tested positive for the presence of the bacterial groups with significant (P≤0.05) seasonal variation in their densities. Faecal coliforms were detected in counts ranging from 1 CFU/100ml to 2.7 × 104 CFU/100ml. Presumptive E. coli counts ranged generally between 1 CFU/100ml – 1.4 × 105 CFU/100ml while counts of presumptive Vibrio species ranged between 4 CFU/100ml – 1.4 × 104 CFU/100ml. Molecular identification of the presumptive isolates by polymerase chain reactions PCR gave positive reaction rates of 76.2 percent (381/500) and 69.8 percent (279/400) for E.coli and Vibrio species respectively. The antibiotic susceptibility profiling of 205 PCR-confirmed Vibiro isolates against 18 commomly used antibiotics showed resistance frequencies ranging from 0.5 percent (imipenem) to 96.1 percent (penicillin G) at recommended breakpoint concentrations. Eighty-one percent (166/205) of the Vibrio isolates showed multidrug resistance (resistance to 3 or more antibiotics) with the most common multiple antibiotic resistance phenotype (MARP) being AP-T-TM-SMX-PG-NI-PB, occurring in 8 isolates.
- Full Text:
- Date Issued: 2016
Anti-diabetic and phytochemical analysis of sutherlandia frutescens extracts
- Authors: Adefuye, Ogheneochuko Janet
- Date: 2016
- Subjects: Medicinal plants -- Africa , Traditional medicine -- Africa , Herbs -- Therapeutic use -- Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/3549 , vital:20441
- Description: In Africa, the importance of medicinal plants in folklore medicine and their contribution to primary healthcare is well recognized. Across the continent, local herbal mixtures still provide the only therapeutic option for about 80% of the population. The vast floral diversity and the intrinsic ethnobotanical knowledge has been the backbone of localized traditional herbal medical practices. In Africa, an estimated 5400 of the 60000 described plant taxa possess over 16300 therapeutic uses. Similarly, with a therapeutic flora comprising of approximately 650 species, herbal medical practitioners in South Africa, make use of a plethora of plants to treat different human diseases and infections. Over the years, studies have identified numerous plant species with potential against chronic metabolic diseases including type 2 diabetes mellitus (T2DM). Globally, the incidence and prevalence of T2DM have reached epidemic proportions affecting people of all ages, nationalities and ethnicity. Considered the fourth leading cause of deaths by disease, T2DM is a global health crisis with an estimated diagnosis and mortality frequency of 1 every 5 seconds and 1 every 7 seconds respectively. Though the exact pathophysiology of T2DM is not entirely understood, initial peripheral insulin resistance in adipose tissue, liver, and skeletal muscle with subsequent pancreatic β-cell dysfunction resulting from an attempt to compensate for insulin resistance is a common feature of the disease. The current approach to treating T2DM is the use of oral antidiabetic agents (OAAs), insulin, and incretin-based drugs in an attempt to achieve glycaemic control and maintain glucose homeostasis. However, conventional anti-T2DM drugs have been shown to have limited efficacies and serious adverse effects. Hence, the need for newer, more efficacious and safer anti-T2DM agents. Sutherlandia frutescens subsp. microphylla is a flowering shrub of the pea family (Fabaceae/Leguminaceae) found mainly in the Western Cape and Karoo regions of Southern Africa. Concoctions of various parts of the plant are used in the management of different ailments including T2DM. However, despite extensive biological and pharmacological studies, few analyses exist of the chemical constituents of S. frutescens and no Triple Time of Flight Liquid Chromatography with Mass Spectrometry (Triple TOF LC/MS/MS) analysis has been performed. The initial aim of this study was to investigate the phytochemical profile of hot aqueous, cold aqueous, 80% ethanolic, 100% ethanolic, 80% methanolic and 100% methanolic extracts of a single source S. frutescens plant material using colorimetric and spectrophotometric analysis. The hot aqueous extractant was found to be the best extractant for S. frutescens, yielding 1.99 g of crude extract from 16 g fresh powdered plant material. This data suggests that application of heat and water as the extractant (hot aqueous) could play a vital role in extraction of bioactive compounds from S. frutescens and also justifies the traditional use of a tea infusion of S. frutescens. Colorimetric analysis revealed the presence of flavonoids, flavonols, tannins, and phenols in all extracts with varying intensity. The organic extracts 100% methanol, 80% and 100% ethanol exhibited high color intensity (+++) for flavonoids and flavonols respectively, while all the extracts exhibited a moderate color intensity (++) for tannins and phenols. Spectrophotometric analysis of S. frutescens extracts revealed that all the organic extracts contained a significantly higher concentration (in mg/g of extract) of flavonols and tannins when compared to the aqueous extracts. All extracts contained approximately equal levels of phenols. These data confirm the presence of all four groups of bioactive phytocompounds in the S. frutescens extracts used in this study, and also confirm that different solvent extractants possess the capability to differentially extract specific groups of phytocompounds. in individual extracts. Further comparison of these compounds with online databases of anti-diabetic phytocompounds led to the preliminary identification of 10 possible anti-diabetic compounds; α-Pinene, Limonene, Sabinene, Carvone, Myricetin, Rutin, Stigmasterol, Emodin, Sarpagine and Hypoglycin B in crude and solid phase extraction (SPE) fractions of S. frutesecens. Furthermore, using two hepatic cell lines (Chang and HepG2) as an in-vtro model system, the anti-T2DM properties of crude aqueous and organic extracts of S. frutescents was investigated and compared. Both aqueous and organic extracts of S. frutescens were found to decrease gluconeogenesis, increase glucose uptake and decrease lipid accumulation (Triacylglycerol, Diacylglycerol, and Monoacylglycerol) in Chang and HepG2 hepatic cell cultures made insulin resistant (IR) following exposure to high concentration of insulin and fructose. Using real-time quantitative reverse transcriptase polymerase chain reaction (qRT-PCR), the aqueous and organic extracts of S. frutescens were confirmed to regulate the expression of Vesicle-associated membrane protein 3 (VAMP3), Mitogen-activated protein kinase 8 (MAPK8), and Insulin receptor substrate 1 (IRS1) in insulin resistant hepatic cells. IR-mediated downregulation of VAMP3, MAPK8, and IRS1 mRNA in IR HepG2 hepatic cell cultures was reversed in the presence of aqueous and organic extracts of S. frutescens. The hot aqueous extract displayed the highest activity in all the assays, while all the organic extracts displayed similar potency. In conclusion, this study reports that aqueous and organic extracts of S. frutescens possess numerous anti-diabetic compounds that can be further investigated for the development of new, more efficacious and less toxic anti-diabetic agents. The presence of multiple compounds in a single extract does suggest a synergistic or combinatorial therapeutic effect. These findings support the burgeoning body of in-vivo and in-vitro literature evidence on the anti-diabetic properties of S. frutescens and its use in folklore medicine.
- Full Text:
- Date Issued: 2016
- Authors: Adefuye, Ogheneochuko Janet
- Date: 2016
- Subjects: Medicinal plants -- Africa , Traditional medicine -- Africa , Herbs -- Therapeutic use -- Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/3549 , vital:20441
- Description: In Africa, the importance of medicinal plants in folklore medicine and their contribution to primary healthcare is well recognized. Across the continent, local herbal mixtures still provide the only therapeutic option for about 80% of the population. The vast floral diversity and the intrinsic ethnobotanical knowledge has been the backbone of localized traditional herbal medical practices. In Africa, an estimated 5400 of the 60000 described plant taxa possess over 16300 therapeutic uses. Similarly, with a therapeutic flora comprising of approximately 650 species, herbal medical practitioners in South Africa, make use of a plethora of plants to treat different human diseases and infections. Over the years, studies have identified numerous plant species with potential against chronic metabolic diseases including type 2 diabetes mellitus (T2DM). Globally, the incidence and prevalence of T2DM have reached epidemic proportions affecting people of all ages, nationalities and ethnicity. Considered the fourth leading cause of deaths by disease, T2DM is a global health crisis with an estimated diagnosis and mortality frequency of 1 every 5 seconds and 1 every 7 seconds respectively. Though the exact pathophysiology of T2DM is not entirely understood, initial peripheral insulin resistance in adipose tissue, liver, and skeletal muscle with subsequent pancreatic β-cell dysfunction resulting from an attempt to compensate for insulin resistance is a common feature of the disease. The current approach to treating T2DM is the use of oral antidiabetic agents (OAAs), insulin, and incretin-based drugs in an attempt to achieve glycaemic control and maintain glucose homeostasis. However, conventional anti-T2DM drugs have been shown to have limited efficacies and serious adverse effects. Hence, the need for newer, more efficacious and safer anti-T2DM agents. Sutherlandia frutescens subsp. microphylla is a flowering shrub of the pea family (Fabaceae/Leguminaceae) found mainly in the Western Cape and Karoo regions of Southern Africa. Concoctions of various parts of the plant are used in the management of different ailments including T2DM. However, despite extensive biological and pharmacological studies, few analyses exist of the chemical constituents of S. frutescens and no Triple Time of Flight Liquid Chromatography with Mass Spectrometry (Triple TOF LC/MS/MS) analysis has been performed. The initial aim of this study was to investigate the phytochemical profile of hot aqueous, cold aqueous, 80% ethanolic, 100% ethanolic, 80% methanolic and 100% methanolic extracts of a single source S. frutescens plant material using colorimetric and spectrophotometric analysis. The hot aqueous extractant was found to be the best extractant for S. frutescens, yielding 1.99 g of crude extract from 16 g fresh powdered plant material. This data suggests that application of heat and water as the extractant (hot aqueous) could play a vital role in extraction of bioactive compounds from S. frutescens and also justifies the traditional use of a tea infusion of S. frutescens. Colorimetric analysis revealed the presence of flavonoids, flavonols, tannins, and phenols in all extracts with varying intensity. The organic extracts 100% methanol, 80% and 100% ethanol exhibited high color intensity (+++) for flavonoids and flavonols respectively, while all the extracts exhibited a moderate color intensity (++) for tannins and phenols. Spectrophotometric analysis of S. frutescens extracts revealed that all the organic extracts contained a significantly higher concentration (in mg/g of extract) of flavonols and tannins when compared to the aqueous extracts. All extracts contained approximately equal levels of phenols. These data confirm the presence of all four groups of bioactive phytocompounds in the S. frutescens extracts used in this study, and also confirm that different solvent extractants possess the capability to differentially extract specific groups of phytocompounds. in individual extracts. Further comparison of these compounds with online databases of anti-diabetic phytocompounds led to the preliminary identification of 10 possible anti-diabetic compounds; α-Pinene, Limonene, Sabinene, Carvone, Myricetin, Rutin, Stigmasterol, Emodin, Sarpagine and Hypoglycin B in crude and solid phase extraction (SPE) fractions of S. frutesecens. Furthermore, using two hepatic cell lines (Chang and HepG2) as an in-vtro model system, the anti-T2DM properties of crude aqueous and organic extracts of S. frutescents was investigated and compared. Both aqueous and organic extracts of S. frutescens were found to decrease gluconeogenesis, increase glucose uptake and decrease lipid accumulation (Triacylglycerol, Diacylglycerol, and Monoacylglycerol) in Chang and HepG2 hepatic cell cultures made insulin resistant (IR) following exposure to high concentration of insulin and fructose. Using real-time quantitative reverse transcriptase polymerase chain reaction (qRT-PCR), the aqueous and organic extracts of S. frutescens were confirmed to regulate the expression of Vesicle-associated membrane protein 3 (VAMP3), Mitogen-activated protein kinase 8 (MAPK8), and Insulin receptor substrate 1 (IRS1) in insulin resistant hepatic cells. IR-mediated downregulation of VAMP3, MAPK8, and IRS1 mRNA in IR HepG2 hepatic cell cultures was reversed in the presence of aqueous and organic extracts of S. frutescens. The hot aqueous extract displayed the highest activity in all the assays, while all the organic extracts displayed similar potency. In conclusion, this study reports that aqueous and organic extracts of S. frutescens possess numerous anti-diabetic compounds that can be further investigated for the development of new, more efficacious and less toxic anti-diabetic agents. The presence of multiple compounds in a single extract does suggest a synergistic or combinatorial therapeutic effect. These findings support the burgeoning body of in-vivo and in-vitro literature evidence on the anti-diabetic properties of S. frutescens and its use in folklore medicine.
- Full Text:
- Date Issued: 2016
In vitro evaluation of antimicrobial and antioxidant activities of olea europaea subsp. africana and euryops brevipapposus used by Cala community folkloric medicine for the management of infections associated with chronic non-communicable diseases
- Authors: Adegborioye, Abiodun
- Date: 2016
- Subjects: Antioxidants Medicinal plants Traditional medicine -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/4869 , vital:28624
- Description: Chronic non-communicable diseses are a global public health challenge that continuously threatens the development and health of humans. Risk factors such as unbalanced diet-the high consumption of processed food or food from animal origin are responsible for NCDs. NCDs result in weakened immune system, making the host susceptible to opportunistic infections. Thus, the NCDs burden is most times chronic and multiple with the illness and suffering of the affected person numerous. The lack of cure for NCDs, the high cost of drugs, their high side-effects, and the emergence of multiple drug resistance has given rise to the investigation of other sources for therapeutic cure such as medicinal plants. The ethanol, n-hexane and ethyl acetate extracts of Olea europaea were analysed for their antioxidant and antimicrobial activities. The essential oil was also analysed for their chemical constituents. The n-hexane extracts of O. europaea exhibited no inhibition against all of the microorganisms tested, while the ethyl acetate and ethanol extracts exhibited inhibition, with minimum inhibitory concentration values between 0.625 mg/ml to 1.25 mg/ml. The ethanol leaf and ethyl acetate stem extracts exhibited significant activity in the inhibition of 2, 2-azinobis-(3-ethylbenzothiazolin - 6-sulfonic acid diammonium salt (ABTS) free radical, the n-hexane leaf extract had the overall significant lipid peroxidation inhibition activity, while in the inhibition of 2, 2- diphenyl-1-picrylhydrazyl radical (DPPH), the ethanol and ethyl acetate leaf extracts had strong activity. Nonanal, phytol, α-Pinene, α-Phellandrene, spatulenol and farnesol were some of chemical components identified after the GC-MS analysis of O. europaea oil. In the final part of the dissertation, Euryops brevipapposus essential oil was assessed for the antioxidant activities using free radical scavenging assays. In addition to this, the antimicrobial activities were assessed and the chemical composition was analysed using GC-MS. The essential oil demonstrated significant antioxidant activity against 2, 2-diphenyl-2-picryl-hydrazyl free radical (DPPH), 2, 2′-azino-bis (3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) and lipid peroxides with IC50 value of 0.0000000671 mg/ml, 1.05 mg/ml, and 1.170 mg/ml respectively. The essential oil also showed significant activity against all microorganisms tested with minimum inhibitory concentration (MIC) values between 0.055 mg/ml to 0.5 mg/ml. α-pinene, α- Phellandrene, germacrene D, β-pinene, trans- β.-Ocimene, bicyclogermacrene and β -Phellandrene were some of the chemical compounds identified in E. brevipapposus oil. The study has shown that E. brevipapposus and O. europaea are abundant in phytochemical compounds which were thought to be the root cause for the activities demonstrated. Therefore, these therapeutic properties observed validate and elucidate the traditional usage of the both plants in the treatment /management of diseases.
- Full Text:
- Date Issued: 2016
- Authors: Adegborioye, Abiodun
- Date: 2016
- Subjects: Antioxidants Medicinal plants Traditional medicine -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/4869 , vital:28624
- Description: Chronic non-communicable diseses are a global public health challenge that continuously threatens the development and health of humans. Risk factors such as unbalanced diet-the high consumption of processed food or food from animal origin are responsible for NCDs. NCDs result in weakened immune system, making the host susceptible to opportunistic infections. Thus, the NCDs burden is most times chronic and multiple with the illness and suffering of the affected person numerous. The lack of cure for NCDs, the high cost of drugs, their high side-effects, and the emergence of multiple drug resistance has given rise to the investigation of other sources for therapeutic cure such as medicinal plants. The ethanol, n-hexane and ethyl acetate extracts of Olea europaea were analysed for their antioxidant and antimicrobial activities. The essential oil was also analysed for their chemical constituents. The n-hexane extracts of O. europaea exhibited no inhibition against all of the microorganisms tested, while the ethyl acetate and ethanol extracts exhibited inhibition, with minimum inhibitory concentration values between 0.625 mg/ml to 1.25 mg/ml. The ethanol leaf and ethyl acetate stem extracts exhibited significant activity in the inhibition of 2, 2-azinobis-(3-ethylbenzothiazolin - 6-sulfonic acid diammonium salt (ABTS) free radical, the n-hexane leaf extract had the overall significant lipid peroxidation inhibition activity, while in the inhibition of 2, 2- diphenyl-1-picrylhydrazyl radical (DPPH), the ethanol and ethyl acetate leaf extracts had strong activity. Nonanal, phytol, α-Pinene, α-Phellandrene, spatulenol and farnesol were some of chemical components identified after the GC-MS analysis of O. europaea oil. In the final part of the dissertation, Euryops brevipapposus essential oil was assessed for the antioxidant activities using free radical scavenging assays. In addition to this, the antimicrobial activities were assessed and the chemical composition was analysed using GC-MS. The essential oil demonstrated significant antioxidant activity against 2, 2-diphenyl-2-picryl-hydrazyl free radical (DPPH), 2, 2′-azino-bis (3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) and lipid peroxides with IC50 value of 0.0000000671 mg/ml, 1.05 mg/ml, and 1.170 mg/ml respectively. The essential oil also showed significant activity against all microorganisms tested with minimum inhibitory concentration (MIC) values between 0.055 mg/ml to 0.5 mg/ml. α-pinene, α- Phellandrene, germacrene D, β-pinene, trans- β.-Ocimene, bicyclogermacrene and β -Phellandrene were some of the chemical compounds identified in E. brevipapposus oil. The study has shown that E. brevipapposus and O. europaea are abundant in phytochemical compounds which were thought to be the root cause for the activities demonstrated. Therefore, these therapeutic properties observed validate and elucidate the traditional usage of the both plants in the treatment /management of diseases.
- Full Text:
- Date Issued: 2016
Fluorescence properties of alloyed ZnSeS quantum dots overcoated with ZnTe and ZnTe/ZnS shells
- Adegoke, Oluwasesan, Mashazi, Philani N, Nyokong, Tebello, Forbes, Patricia B C
- Authors: Adegoke, Oluwasesan , Mashazi, Philani N , Nyokong, Tebello , Forbes, Patricia B C
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/240754 , vital:50868 , xlink:href="https://doi.org/10.1016/j.optmat.2016.02.024"
- Description: Fluorescent alloyed ternary ZnSeS quantum dots (QDs) have been synthesized via the pyrolysis of organometallic precursors. The effects of passivation of ZnTe and ZnTe/ZnS shells on the optical properties of the ternary alloyed ZnSeS core have been studied. A ligand exchange reaction using L-cysteine as a capping ligand was used to obtain water-soluble nanocrystals. The nanocrystals were each characterized by UV/vis absorption and fluorescence spectroscopy, transmission electron microscopy, X-ray diffractometry (XRD) and X-ray photoelectron spectroscopy (XPS). The photoluminescence (PL) quantum yield (QY) of alloyed ZnSeS QDs was 14% and this value increased to 27% when ZnTe was overcoated around the surface but further coating with a ZnS shell decreased the PL QY slightly to 24%. This implies that ZnTe shell suppressed non-radiative recombination exciton states in the alloyed core while further layering with a ZnS shell offered no further improvement in suppressing the defect states. XPS analysis confirmed the presence of the first shell layering but showed a weakened intensity signal of S (2p) and Se (3d) for the ZnSeS/ZnTe/ZnS QDs. Our work demonstrates for the first time that shell passivation of alloyed Zn-based QDs can offer improved optical properties. We hope the optical information presented in this work will be useful in the selection of alloyed Zn-based QDs appropriate for the intended application.
- Full Text:
- Date Issued: 2016
- Authors: Adegoke, Oluwasesan , Mashazi, Philani N , Nyokong, Tebello , Forbes, Patricia B C
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/240754 , vital:50868 , xlink:href="https://doi.org/10.1016/j.optmat.2016.02.024"
- Description: Fluorescent alloyed ternary ZnSeS quantum dots (QDs) have been synthesized via the pyrolysis of organometallic precursors. The effects of passivation of ZnTe and ZnTe/ZnS shells on the optical properties of the ternary alloyed ZnSeS core have been studied. A ligand exchange reaction using L-cysteine as a capping ligand was used to obtain water-soluble nanocrystals. The nanocrystals were each characterized by UV/vis absorption and fluorescence spectroscopy, transmission electron microscopy, X-ray diffractometry (XRD) and X-ray photoelectron spectroscopy (XPS). The photoluminescence (PL) quantum yield (QY) of alloyed ZnSeS QDs was 14% and this value increased to 27% when ZnTe was overcoated around the surface but further coating with a ZnS shell decreased the PL QY slightly to 24%. This implies that ZnTe shell suppressed non-radiative recombination exciton states in the alloyed core while further layering with a ZnS shell offered no further improvement in suppressing the defect states. XPS analysis confirmed the presence of the first shell layering but showed a weakened intensity signal of S (2p) and Se (3d) for the ZnSeS/ZnTe/ZnS QDs. Our work demonstrates for the first time that shell passivation of alloyed Zn-based QDs can offer improved optical properties. We hope the optical information presented in this work will be useful in the selection of alloyed Zn-based QDs appropriate for the intended application.
- Full Text:
- Date Issued: 2016
Incidence and molecular characterization of Hepatitis E virus from swine herds in the Eastern Cape province, South Africa
- Authors: Adelabu, Olusesan Adeyemi
- Date: 2016
- Subjects: Hepatitis -- South Africa -- Eastern Cape Virology -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/13966 , vital:39734
- Description: Hepatitis E virus-mediated infection is a serious public health concern in economically developing nations of the world. Globally, four major genotypes of HEV have been documented and the swine HEV identified to date in different countries belongs to either genotype 3 or 4. It has been reported to cross species barrier and cause infections in humans. Hence, Hepatitis E has been suggested to be zoonotic owing to the increase of evidence through various studies. Thus far, genotypes 1 and 2 are exclusively found in human population. However, little data are available regarding the occurrence of HEV in South Africa, especially in the Eastern Cape Province. Hence, this study was designed to assess the prevalence of Hepatitis E Virus among swine herd in selected communal and commercial farms in the Eastern Cape Province of South Africa. A total of 160 faecal samples were collected from swine herds in Amathole and Chris Hani District Municipalities of Eastern Cape Province and screened for the presence of HEV. Faecal samples were collected, using sterile swabs, from swine between the age of 2 to 6 months old, placed on ice and transported to the laboratory for further analysis. Viral RNA extraction was carried out followed by nested reverse-transcriptase polymerase chain reaction was used for amplification, after which the amplified products were examined by electrophoresis and viewed under ultraviolet illumination. The positive PCR products were sent for sequencing. Of the 160 faecal samples screened, only seven were positive (4.4percent) for HEV. The nucleotide sequence analyses revealed isolates UFT 01-03 sharing 82percent to 99percent identities with other strains with accession numbers KX896664, KX896665 and KX896666 and UMCF 01-04 with KX896667, KX896668, KX896669 and KX896670 from different regions of the world Phylogenetic analysis also showed that all seven isolates from this study clustered with both human and swine HEV from different geographical regions of the world especially with Japan Human and swine strains, Netherland swine HEV strains (AY032758, AF332620) and human HEV strain from France (JQ763611). We conclude that HEV is present among swine in the Eastern Cape Province, albeit in low incidence, and this does have public health implications. There is need for maintenance of high hygienic standards in order to prevent human infections through swine faecal materials and appropriate cooking of pork is highly advised.
- Full Text:
- Date Issued: 2016
- Authors: Adelabu, Olusesan Adeyemi
- Date: 2016
- Subjects: Hepatitis -- South Africa -- Eastern Cape Virology -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/13966 , vital:39734
- Description: Hepatitis E virus-mediated infection is a serious public health concern in economically developing nations of the world. Globally, four major genotypes of HEV have been documented and the swine HEV identified to date in different countries belongs to either genotype 3 or 4. It has been reported to cross species barrier and cause infections in humans. Hence, Hepatitis E has been suggested to be zoonotic owing to the increase of evidence through various studies. Thus far, genotypes 1 and 2 are exclusively found in human population. However, little data are available regarding the occurrence of HEV in South Africa, especially in the Eastern Cape Province. Hence, this study was designed to assess the prevalence of Hepatitis E Virus among swine herd in selected communal and commercial farms in the Eastern Cape Province of South Africa. A total of 160 faecal samples were collected from swine herds in Amathole and Chris Hani District Municipalities of Eastern Cape Province and screened for the presence of HEV. Faecal samples were collected, using sterile swabs, from swine between the age of 2 to 6 months old, placed on ice and transported to the laboratory for further analysis. Viral RNA extraction was carried out followed by nested reverse-transcriptase polymerase chain reaction was used for amplification, after which the amplified products were examined by electrophoresis and viewed under ultraviolet illumination. The positive PCR products were sent for sequencing. Of the 160 faecal samples screened, only seven were positive (4.4percent) for HEV. The nucleotide sequence analyses revealed isolates UFT 01-03 sharing 82percent to 99percent identities with other strains with accession numbers KX896664, KX896665 and KX896666 and UMCF 01-04 with KX896667, KX896668, KX896669 and KX896670 from different regions of the world Phylogenetic analysis also showed that all seven isolates from this study clustered with both human and swine HEV from different geographical regions of the world especially with Japan Human and swine strains, Netherland swine HEV strains (AY032758, AF332620) and human HEV strain from France (JQ763611). We conclude that HEV is present among swine in the Eastern Cape Province, albeit in low incidence, and this does have public health implications. There is need for maintenance of high hygienic standards in order to prevent human infections through swine faecal materials and appropriate cooking of pork is highly advised.
- Full Text:
- Date Issued: 2016
Traditional and cultural practices and the rights of women : a study of widowhood practices among the Akans in Ghana
- Authors: Afari-Twumasi, Lucy
- Date: 2016
- Subjects: Widows -- Legal status, laws, etc. -- Ghana Widowhood -- Ghana Akan (African people) -- Social life and customs
- Language: English
- Type: Thesis , Masters , MPhil
- Identifier: http://hdl.handle.net/10353/2844 , vital:28106
- Description: The study investigates the human rights violations that underlie widowhood practices in Cape Coast and Komenda in the Central Region of Ghana. Review of the relevant literature on widowhood practices suggests that widowhood practices are a global cultural phenomenon, which is not confined to Sub-Sahara Africa. A survey of relevant studies on the phenomenon suggests that there are two competing perceptions on African widowhood practices: (1) a dominant negative perspective and (2) a minor positive perspective. The dominant negative perspective, which receives overwhelming research attention, focuses only on the negative characteristics of widowhood while the minor positive perspective which receives scanty research attention, rejects the criticisms levelled against widowhood practices as being externally influenced by Christianity and Western Feminism. Various stakeholders within the Akan community were given an opportunity to retell their own versions of widowhood practices. In order to achieve this purpose, the research extracted competing narratives from all the multiple sample subgroups of the proposed study: widows; widow family heads; chiefs; widowhood ritual practitioners; elderly female supervisors of widowhood practices; an official from the Commission for Human Rights and Administrative Justice (CHRAJ); an official from the Ministry of Women and Children Affairs (MOWAC); and an official from the Domestic Violence and Victims Support Unit (DOVVSU) of Ghana. The study found out that despite legislative intervention and policy frameworks, the practice still persist among the Akan communities in Ghana. The reasons for the continued existence of such rituals are explained followed by recommendations for possible solutions.
- Full Text:
- Date Issued: 2016
- Authors: Afari-Twumasi, Lucy
- Date: 2016
- Subjects: Widows -- Legal status, laws, etc. -- Ghana Widowhood -- Ghana Akan (African people) -- Social life and customs
- Language: English
- Type: Thesis , Masters , MPhil
- Identifier: http://hdl.handle.net/10353/2844 , vital:28106
- Description: The study investigates the human rights violations that underlie widowhood practices in Cape Coast and Komenda in the Central Region of Ghana. Review of the relevant literature on widowhood practices suggests that widowhood practices are a global cultural phenomenon, which is not confined to Sub-Sahara Africa. A survey of relevant studies on the phenomenon suggests that there are two competing perceptions on African widowhood practices: (1) a dominant negative perspective and (2) a minor positive perspective. The dominant negative perspective, which receives overwhelming research attention, focuses only on the negative characteristics of widowhood while the minor positive perspective which receives scanty research attention, rejects the criticisms levelled against widowhood practices as being externally influenced by Christianity and Western Feminism. Various stakeholders within the Akan community were given an opportunity to retell their own versions of widowhood practices. In order to achieve this purpose, the research extracted competing narratives from all the multiple sample subgroups of the proposed study: widows; widow family heads; chiefs; widowhood ritual practitioners; elderly female supervisors of widowhood practices; an official from the Commission for Human Rights and Administrative Justice (CHRAJ); an official from the Ministry of Women and Children Affairs (MOWAC); and an official from the Domestic Violence and Victims Support Unit (DOVVSU) of Ghana. The study found out that despite legislative intervention and policy frameworks, the practice still persist among the Akan communities in Ghana. The reasons for the continued existence of such rituals are explained followed by recommendations for possible solutions.
- Full Text:
- Date Issued: 2016
A morphogenic and laminated system explanation of position-practice systems and professional development training in mainstreaming education for sustainable development in African universities
- Authors: Agbedahin, Adesuwa Vanessa
- Date: 2016
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/584 , vital:19972
- Description: This research focuses on Education for Sustainable Development (ESD) in Higher Education Institutions (HEIs), particularly in Africa. It explores the roles and practices of these institutions, especially their professionals, in the Anthropocene era where increasing concern for contemporary environmental and sustainability issues and risks emerge. The study presents a longitudinal case study of institutions and participants of the Swedish/African/Asian International Training Programme (ITP) on ESD in Higher Education (HE), who are mostly university educators. This thesis however focuses on African ITP participants only. At a macro level, the research sought to examine how African university educators have contributed to the United Nations Decade of Education for Sustainable Development (UNDESD) through their participation in the ITP (which is a change oriented professional development training programme on ESD) and the associated ESD ‘change projects’. The change projects are ITP participants’ direct attempts to mainstream environment and sustainability issues, concerns, and concepts into core university functions and practices: teaching, research, community engagement, and management operations and policy engagement. At a meso level the study sought insight into how educators in national institutions were supported by sub-regional and regional initiatives, institutions and organisations, including the Mainstreaming of Environment and Sustainability in African (MESA) Universities Partnership programme, especially an initiative supported by the Southern African Development Community Regional Environmental Education Programme to provide (limited) seed funding to three southern African universities to establish what are known as ‘MESA Chairs’, with dedicated time and support for MESA activities in their universities . At a micro level, this research sought to investigate how the position-practice systems and the ITP shape (enable or constrain) effective ESD mainstreaming in higher education, and how the morphogenetic approach and laminated system can be used to understand and explain these dynamics and their relations with meso and macro level engagements. The research sought to understand these dynamics through empirical investigations using survey questionnaires, interviews, document analysis and field visits. The research is constituted as theoretical, conceptual, methodological and analytical exploration using a singular and nested case study research approach, underlaboured by a critical realist ontology, and drawing on a social learning epistemology and social realist morphogenetic interpretive lens. In particular, ontological depth was sought via critical realist laminated system explanation. See Chapter Two for details. This study was carried out in three phases. Phase one encapsulates the investigation of all ITP ESD in higher education alumni who were Asian and African participants from the inception of the ITP to its completion, over a six-year period (2008-2013). This included 280 academics from Asia and Africa in 35 countries in Asia and Africa from 106 institutions in Asia and Africa with their 139 change projects. The outcome of phase one of the research is only included in this thesis as an appendix (see Appendix 3; Agbedahin & Lotz-Sisitka, 2015). However, this phase provided and formed the foundational data that was expanded in phases two and three for the purpose of this study. Phase two of this research concentrated on a less broad population of research participants comprising only all African ITP alumni, from all regions in Africa. The overall data collection and analysis included 162 academics in 23 African countries from 66 institutions with their 81 change projects. The aim was to investigate and provide a morphogenetic explanation of their change projects and how the relationship between participants’ positions and practices (and that of others) may influence ESD mainstreaming in universities. The outcome of this phase two investigation is presented in Chapter Four. In phase three, (nested) case studies of Swaziland, Zambia, and Botswana (in the southern Africa region), which included all the ESD ITP HE participants therein and the three corresponding EE/ESD MESA Chairs, were developed. The population sample in this phase three therefore contained 20 academics, from six institutions with their nine change projects. This phase was characterised by field trips to these countries and in-depth data collection and analysis in order to investigate and deepen the morphogenetic explanations of their change projects and how the relationship between participants’ positions and practices (and that of others) have indeed influenced the ESD mainstreaming in universities. The outcome of this phase three research is presented in Chapters Five, Six and Seven. The final Chapter Eight of this thesis focuses on the seven scalar laminated system perspective and reflections on this research and discussion of these perspectives for supporting the mainstreaming of ESD in African higher education institutions and more specifically in the three case countries and respective institutions presented in Chapters Five, Six, and Seven. The seven scalar laminated system is presented in relation to the position-practice system, and draws on morphogenetic social realist and social learning theory to provide perspective on the actual change processes. Chapter Eight also includes a discussion on social learning and its implication for ESD mainstreaming, and provides recommendations for further research. The outcome of the theoretical exploration underpinning this study provided a potential model for understanding ESD learning and change processes that are facilitated by professional development training programmes in the context of ESD in HE. This study also provides a model for appraising educational changes in time and in space, especially in relation to ESD, or the types of changes that can be brought about by professional development interventions such as those provided by the ITP and how they can be tracked, monitored and documented. For the field of professional or academic development in higher education, this research highlights the significance of the relationship between position-practice systems, professional development interventions and institutional transformation. For the field of ESD in higher education, this study shows the need for in-depth consideration of the position-practice system and sphere of influence of change agents and related stakeholders in and around their institutions in the design and development of professional development programmes. It further sheds light on the laminated system of factors that contextually constrain and/or enable effective ESD mainstreaming at individual, collective, institutional, national, regional and global levels.
- Full Text:
- Date Issued: 2016
- Authors: Agbedahin, Adesuwa Vanessa
- Date: 2016
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/584 , vital:19972
- Description: This research focuses on Education for Sustainable Development (ESD) in Higher Education Institutions (HEIs), particularly in Africa. It explores the roles and practices of these institutions, especially their professionals, in the Anthropocene era where increasing concern for contemporary environmental and sustainability issues and risks emerge. The study presents a longitudinal case study of institutions and participants of the Swedish/African/Asian International Training Programme (ITP) on ESD in Higher Education (HE), who are mostly university educators. This thesis however focuses on African ITP participants only. At a macro level, the research sought to examine how African university educators have contributed to the United Nations Decade of Education for Sustainable Development (UNDESD) through their participation in the ITP (which is a change oriented professional development training programme on ESD) and the associated ESD ‘change projects’. The change projects are ITP participants’ direct attempts to mainstream environment and sustainability issues, concerns, and concepts into core university functions and practices: teaching, research, community engagement, and management operations and policy engagement. At a meso level the study sought insight into how educators in national institutions were supported by sub-regional and regional initiatives, institutions and organisations, including the Mainstreaming of Environment and Sustainability in African (MESA) Universities Partnership programme, especially an initiative supported by the Southern African Development Community Regional Environmental Education Programme to provide (limited) seed funding to three southern African universities to establish what are known as ‘MESA Chairs’, with dedicated time and support for MESA activities in their universities . At a micro level, this research sought to investigate how the position-practice systems and the ITP shape (enable or constrain) effective ESD mainstreaming in higher education, and how the morphogenetic approach and laminated system can be used to understand and explain these dynamics and their relations with meso and macro level engagements. The research sought to understand these dynamics through empirical investigations using survey questionnaires, interviews, document analysis and field visits. The research is constituted as theoretical, conceptual, methodological and analytical exploration using a singular and nested case study research approach, underlaboured by a critical realist ontology, and drawing on a social learning epistemology and social realist morphogenetic interpretive lens. In particular, ontological depth was sought via critical realist laminated system explanation. See Chapter Two for details. This study was carried out in three phases. Phase one encapsulates the investigation of all ITP ESD in higher education alumni who were Asian and African participants from the inception of the ITP to its completion, over a six-year period (2008-2013). This included 280 academics from Asia and Africa in 35 countries in Asia and Africa from 106 institutions in Asia and Africa with their 139 change projects. The outcome of phase one of the research is only included in this thesis as an appendix (see Appendix 3; Agbedahin & Lotz-Sisitka, 2015). However, this phase provided and formed the foundational data that was expanded in phases two and three for the purpose of this study. Phase two of this research concentrated on a less broad population of research participants comprising only all African ITP alumni, from all regions in Africa. The overall data collection and analysis included 162 academics in 23 African countries from 66 institutions with their 81 change projects. The aim was to investigate and provide a morphogenetic explanation of their change projects and how the relationship between participants’ positions and practices (and that of others) may influence ESD mainstreaming in universities. The outcome of this phase two investigation is presented in Chapter Four. In phase three, (nested) case studies of Swaziland, Zambia, and Botswana (in the southern Africa region), which included all the ESD ITP HE participants therein and the three corresponding EE/ESD MESA Chairs, were developed. The population sample in this phase three therefore contained 20 academics, from six institutions with their nine change projects. This phase was characterised by field trips to these countries and in-depth data collection and analysis in order to investigate and deepen the morphogenetic explanations of their change projects and how the relationship between participants’ positions and practices (and that of others) have indeed influenced the ESD mainstreaming in universities. The outcome of this phase three research is presented in Chapters Five, Six and Seven. The final Chapter Eight of this thesis focuses on the seven scalar laminated system perspective and reflections on this research and discussion of these perspectives for supporting the mainstreaming of ESD in African higher education institutions and more specifically in the three case countries and respective institutions presented in Chapters Five, Six, and Seven. The seven scalar laminated system is presented in relation to the position-practice system, and draws on morphogenetic social realist and social learning theory to provide perspective on the actual change processes. Chapter Eight also includes a discussion on social learning and its implication for ESD mainstreaming, and provides recommendations for further research. The outcome of the theoretical exploration underpinning this study provided a potential model for understanding ESD learning and change processes that are facilitated by professional development training programmes in the context of ESD in HE. This study also provides a model for appraising educational changes in time and in space, especially in relation to ESD, or the types of changes that can be brought about by professional development interventions such as those provided by the ITP and how they can be tracked, monitored and documented. For the field of professional or academic development in higher education, this research highlights the significance of the relationship between position-practice systems, professional development interventions and institutional transformation. For the field of ESD in higher education, this study shows the need for in-depth consideration of the position-practice system and sphere of influence of change agents and related stakeholders in and around their institutions in the design and development of professional development programmes. It further sheds light on the laminated system of factors that contextually constrain and/or enable effective ESD mainstreaming at individual, collective, institutional, national, regional and global levels.
- Full Text:
- Date Issued: 2016
Exploring the influence of learners’ participation in an after-school science enrichment programme on their disposition towards science: a case study of Khanya Maths and Science Club
- Authors: Agunbiade, Esther Arinola
- Date: 2016
- Subjects: Mathematics -- Study and teaching Science -- Study and teaching After-school programs Academic achievement
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: http://hdl.handle.net/10962/334 , vital:19949
- Description: The ongoing advancement of science and technology is creating an increasing need for more entrants into science oriented careers. However, numerous studies have fueled growing concerns regarding the poor achievement of learners in science. Over the years, science education researchers have emphasized the importance of the affective domain of learning as a central component of strategies used to address learners’ lack of interest and poor achievement in science. In the literature, the affective domain is characterized by constructs such as disposition, attitude, interest, and motivation. Studies showing a correlation between the affective domain and academic achievement suggest that nurturing a positive disposition towards science is an antecedent to learners’ improved science achievement and entering science fields. This study focuses on the ‘disposition’ aspect of the affective domain, and follows in the path of earlier studies which use the term interchangeably with ‘attitude’. Learners’ experiences in a particular science education environment influence the development of a positive or negative disposition towards science. However, there is a need to explore the factors in the learning environments which influence learners’ disposition towards science. Previous studies have shown that the informal science environment may influence learners’ disposition towards science. One example of an informal science environment is the Khanya Maths and Science Club, which is an after-school science and mathematics enrichment programme in Grahamstown, South Africa. This study explores the influence of learners’ participation in an informal science education environment on their dispositions towards science, using the case of the Khanya Maths and Science Club. This study views disposition through the constructivist-developmental lens. The community of practice elements from situated learning theory is drawn on to explore how learners’ disposition can be influenced by their interactions in the context of the Khanya Maths and Science Club. The pragmatic paradigm is adopted, which considers how well the research tools work to provide answers to the research questions. This thus, provides an avenue for exploring how learners’ disposition towards science is influenced and what factors influenced their shift in disposition through their participation in the club. A mixed-methods approach is employed when focusing on the affective domain sub-constructs of: enjoyment of science, interest in science and perception of science. These are sub-scales in the test of science related attitude (TOSRA) questionnaire which was adapted for use in measuring learners’ attitude before and after 16 weeks of participating in the science club. The particular mixed-methods approach selected can be summarized as quan QUAL since the method is primarily qualitative, but sequential with the quantitative phase preceding the qualitative phase. The TOSRA questionnaire was used as the quantitative data collection instrument while semi-structured interviews and learners’ journal entries were the qualitative data collection instruments. The results revealed significant shifts in learners’ perception of, interest in science and enjoyment of science though interest in science and enjoyment of science shifted appreciably in a positive direction more than the perception of science. It was also found that learners’ attitude towards science was influenced by; instructional characteristics, facilitators/environmental characteristics, learners making connection between science and everyday life and learners’ perceived difficulty of science. These factors variably influenced their attitude towards science in the club, corroborating what had been found in similar studies. This study corroborates what the literature offers for achieving effective outcomes in Afterschool science enrichment programmes. It contributes to the growing body of literature on features for quality outcomes in Afterschool science enrichment programmes. This study also makes a theoretical contribution to science education research particularly with regard to how the emergence of a community of practice framework in the club activities provide useful information for planning club activities and the analysis of learners’ evolving disposition towards science. Key words: Khanya Maths and Science Club, disposition, attitude, after-school enrichment programmes, constructivist-developmental approach, situated learning theory, community of practice, Test of Science Related Attitude (TOSRA).
- Full Text:
- Date Issued: 2016
- Authors: Agunbiade, Esther Arinola
- Date: 2016
- Subjects: Mathematics -- Study and teaching Science -- Study and teaching After-school programs Academic achievement
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: http://hdl.handle.net/10962/334 , vital:19949
- Description: The ongoing advancement of science and technology is creating an increasing need for more entrants into science oriented careers. However, numerous studies have fueled growing concerns regarding the poor achievement of learners in science. Over the years, science education researchers have emphasized the importance of the affective domain of learning as a central component of strategies used to address learners’ lack of interest and poor achievement in science. In the literature, the affective domain is characterized by constructs such as disposition, attitude, interest, and motivation. Studies showing a correlation between the affective domain and academic achievement suggest that nurturing a positive disposition towards science is an antecedent to learners’ improved science achievement and entering science fields. This study focuses on the ‘disposition’ aspect of the affective domain, and follows in the path of earlier studies which use the term interchangeably with ‘attitude’. Learners’ experiences in a particular science education environment influence the development of a positive or negative disposition towards science. However, there is a need to explore the factors in the learning environments which influence learners’ disposition towards science. Previous studies have shown that the informal science environment may influence learners’ disposition towards science. One example of an informal science environment is the Khanya Maths and Science Club, which is an after-school science and mathematics enrichment programme in Grahamstown, South Africa. This study explores the influence of learners’ participation in an informal science education environment on their dispositions towards science, using the case of the Khanya Maths and Science Club. This study views disposition through the constructivist-developmental lens. The community of practice elements from situated learning theory is drawn on to explore how learners’ disposition can be influenced by their interactions in the context of the Khanya Maths and Science Club. The pragmatic paradigm is adopted, which considers how well the research tools work to provide answers to the research questions. This thus, provides an avenue for exploring how learners’ disposition towards science is influenced and what factors influenced their shift in disposition through their participation in the club. A mixed-methods approach is employed when focusing on the affective domain sub-constructs of: enjoyment of science, interest in science and perception of science. These are sub-scales in the test of science related attitude (TOSRA) questionnaire which was adapted for use in measuring learners’ attitude before and after 16 weeks of participating in the science club. The particular mixed-methods approach selected can be summarized as quan QUAL since the method is primarily qualitative, but sequential with the quantitative phase preceding the qualitative phase. The TOSRA questionnaire was used as the quantitative data collection instrument while semi-structured interviews and learners’ journal entries were the qualitative data collection instruments. The results revealed significant shifts in learners’ perception of, interest in science and enjoyment of science though interest in science and enjoyment of science shifted appreciably in a positive direction more than the perception of science. It was also found that learners’ attitude towards science was influenced by; instructional characteristics, facilitators/environmental characteristics, learners making connection between science and everyday life and learners’ perceived difficulty of science. These factors variably influenced their attitude towards science in the club, corroborating what had been found in similar studies. This study corroborates what the literature offers for achieving effective outcomes in Afterschool science enrichment programmes. It contributes to the growing body of literature on features for quality outcomes in Afterschool science enrichment programmes. This study also makes a theoretical contribution to science education research particularly with regard to how the emergence of a community of practice framework in the club activities provide useful information for planning club activities and the analysis of learners’ evolving disposition towards science. Key words: Khanya Maths and Science Club, disposition, attitude, after-school enrichment programmes, constructivist-developmental approach, situated learning theory, community of practice, Test of Science Related Attitude (TOSRA).
- Full Text:
- Date Issued: 2016
The need for conflict management in organisations (a health insurance company, Port Elizabeth)
- Authors: Ajam, Razaana
- Date: 2016
- Subjects: Conflict management , Organizational change -- South Africa -- Eastern Cape , Organizational behavior -- South Africa -- Eastern Cape , Interpersonal relations
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10948/3852 , vital:20469
- Description: Conflict is evident in many spheres of life, however this study concentrated more specifically on conflict relating to organisations. Organisational conflict is seen “as any social collectivity, organisations such as private sector companies, government departments, schools and universities, non-governmental organisations, and political parties all experience internal conflict in varying degrees” (Bradshaw, 2008: 22). Each individual coming into a workplace has created his or her own set of challenges especially in the brutal arena of business. Conflict has destructive and productive qualities that can diminish or elevate processes within an organization (Stone, 1999). If it is not harnessed properly or dealt with in the correct manner, it can damage the reputation of a business; resulting in its downfall and this in turn contaminates and affects peripheral businesses associated with the organisation downstream. This study explored the following key aspects: Background of organisational conflict and its management; Background of the organization; Whether these two areas mentioned above can work together to create a cost effective and efficient outcome when dealing with conflict. The research adopted a mixed method approach with predominant focus on qualitative research methodology. The main focus of this study was conflict management within organisations and to probe and determine whether companies see the need to employ the field of conflict management as a strategy in times of fluctuating dispositions. It is evident that the organisation may not be fully aware or make use of alternative conflict resolution strategies and that the main causes of conflict can be eliminated such as poor communication, ill-defined job descriptions and objectives and differing of opinions. The need to employ alternative methods of conflict management may be emphasised by looking at the costs that conflict produces and the use of limited vital resources and the loss of human capital.
- Full Text:
- Date Issued: 2016
- Authors: Ajam, Razaana
- Date: 2016
- Subjects: Conflict management , Organizational change -- South Africa -- Eastern Cape , Organizational behavior -- South Africa -- Eastern Cape , Interpersonal relations
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10948/3852 , vital:20469
- Description: Conflict is evident in many spheres of life, however this study concentrated more specifically on conflict relating to organisations. Organisational conflict is seen “as any social collectivity, organisations such as private sector companies, government departments, schools and universities, non-governmental organisations, and political parties all experience internal conflict in varying degrees” (Bradshaw, 2008: 22). Each individual coming into a workplace has created his or her own set of challenges especially in the brutal arena of business. Conflict has destructive and productive qualities that can diminish or elevate processes within an organization (Stone, 1999). If it is not harnessed properly or dealt with in the correct manner, it can damage the reputation of a business; resulting in its downfall and this in turn contaminates and affects peripheral businesses associated with the organisation downstream. This study explored the following key aspects: Background of organisational conflict and its management; Background of the organization; Whether these two areas mentioned above can work together to create a cost effective and efficient outcome when dealing with conflict. The research adopted a mixed method approach with predominant focus on qualitative research methodology. The main focus of this study was conflict management within organisations and to probe and determine whether companies see the need to employ the field of conflict management as a strategy in times of fluctuating dispositions. It is evident that the organisation may not be fully aware or make use of alternative conflict resolution strategies and that the main causes of conflict can be eliminated such as poor communication, ill-defined job descriptions and objectives and differing of opinions. The need to employ alternative methods of conflict management may be emphasised by looking at the costs that conflict produces and the use of limited vital resources and the loss of human capital.
- Full Text:
- Date Issued: 2016
The taxability of rewards from suppliers
- Authors: Akoonjie, Ahmed Hassen
- Date: 2016
- Subjects: Taxation -- South Africa Industrial procurement -- South Africa
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: http://hdl.handle.net/10948/11253 , vital:26902
- Description: Successful business in today’s competitive climate thrives on building relationships with one’s suppliers, clientele and employees. Businesses, as a form of strategic engagement, extend their appreciation and recognition to these key role players with rewards (or incentives) such as prizes, holidays and free goods and/or services. This treatise examines the taxation implications of such rewards and determines that the market value thereof should be taxed in the hands of their recipients. This study also investigates possible indicators (or points of reference) to establish such market value and suggests alternate values that may be ascribed thereto for inclusion in the recipient’s gross income. Where the rewards are passed onwards by the recipient to its employees, fringe benefit consequences are occasioned and this study observes that the market value thereof should be taxed in the employees’ hands. The study goes on further to consider the position of the supplier (or provider) of the rewards and finds that the supplier is entitled to a deduction of the cost of the rewards it has provided to its clients or customers. This study also reflects upon the penal implications of not including the market value of rewards in gross income and notes that such non-inclusion constitutes a fiscal loss and is subject to an understatement penalty. Key recommendations on how such omission may be addressed by the tax authorities are also presented.
- Full Text:
- Date Issued: 2016
- Authors: Akoonjie, Ahmed Hassen
- Date: 2016
- Subjects: Taxation -- South Africa Industrial procurement -- South Africa
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: http://hdl.handle.net/10948/11253 , vital:26902
- Description: Successful business in today’s competitive climate thrives on building relationships with one’s suppliers, clientele and employees. Businesses, as a form of strategic engagement, extend their appreciation and recognition to these key role players with rewards (or incentives) such as prizes, holidays and free goods and/or services. This treatise examines the taxation implications of such rewards and determines that the market value thereof should be taxed in the hands of their recipients. This study also investigates possible indicators (or points of reference) to establish such market value and suggests alternate values that may be ascribed thereto for inclusion in the recipient’s gross income. Where the rewards are passed onwards by the recipient to its employees, fringe benefit consequences are occasioned and this study observes that the market value thereof should be taxed in the employees’ hands. The study goes on further to consider the position of the supplier (or provider) of the rewards and finds that the supplier is entitled to a deduction of the cost of the rewards it has provided to its clients or customers. This study also reflects upon the penal implications of not including the market value of rewards in gross income and notes that such non-inclusion constitutes a fiscal loss and is subject to an understatement penalty. Key recommendations on how such omission may be addressed by the tax authorities are also presented.
- Full Text:
- Date Issued: 2016