The influence of financial socialisation agents on financial knowledge, financial self-efficacy and financial behaviour among South African consumers
- Authors: Maswena, Kaelo
- Date: 2022-04-06
- Subjects: Financial literacy South Africa , Finance, Personal South Africa , Budgets, Personal South Africa , Consumer behavior South Africa , Consumers Attitudes , Life skills South Africa , Social learning South Africa , Self-control South Africa , Socialization South Africa , Financial socialisation agents
- Language: English
- Type: Master's thesis , text
- Identifier: http://hdl.handle.net/10962/232421 , vital:49990
- Description: There is a need to promote positive financial behaviour in South Africa. According to the Human Sciences Research Council (2018), South African financial behaviour culture emphasises a financially vulnerable nation in terms of not having enough income for future planning and lacking financial self-control. In its key role in influencing financial behaviour, financial socialisation, which is characterised by interactions with indirect, or purposive financial education and communication of financial norms influencing financial behaviours, attitudes, knowledge, capabilities, and self-efficacy of consumers, is the topic of this study. The purpose of the study was to investigate the influence of financial socialisation agents on financial (actual and self-assessed) knowledge, financial self-efficacy and financial behaviour among South African consumers. Based on Glenn’s (2018) framework, Xiao et al. (2009) socialisation and Moschis et al. (1978) consumer socialisation theory, the financial socialisation theoretical framework is provided for this study. Literature review provided an overview of past studies on the concepts of financial socialisation, financial (actual and self-assessed) knowledge, financial self-efficacy and financial behaviour. Therefore, a positivistic research paradigm was adopted, which used a cross-sectional correlational research methodology. This study analysed data primarily collected by a questionnaire survey of South African social attitudes to financial literacy by the Human Sciences Research Council (2011), using a multi-staged sampling technique in all South African provinces of consumers of 16 years and older. Descriptive statistics showed that most respondents were black African females between the ages of 26 and 35 years. Most held Matric certificates and were in paid employment for 30 hours or more per week. Most respondents considered family to be the most influential financial socialisation agent, followed by friends, then the bank. Actual financial knowledge of respondents, was indicated as relatively high. Results on self-assessed financial knowledge showed that most of the respondents considered their level of financial knowledge to be neutral. Using Pearson product-moment correlations to measure the strength and correlations of relationships, positive significant correlations were found between financial socialisation agents, financial (actual and self-assessed) knowledge and financial self-efficacy, while a negative and insignificant correlation was found between financial socialisation agents and financial behaviour. Multiple regression analysis results testing the hypotheses of the study demonstrated that financial socialisation agents have a significant positive influence on financial (actual and self-assessed) knowledge and financial self-efficacy; a significant influence on financial behaviour was not reported. Self-assessed financial knowledge showed a positive significant influence on financial self-efficacy and actual financial knowledge had an insignificant negative influence on financial self-efficacy. Actual financial knowledge had a significant positive influence on financial behaviour, whereby a positive yet insignificant relationship was found between self-assessed knowledge and financial behaviour. In the end, recommendations for the results indicate that financial educators need to develop a financial education plan that will include other content areas of financial knowledge such as identified by Huston (2010) and Lusardi and Mitchell (2011); the most important recommendation would be to help consumers have an accurate understanding of their own level of financial knowledge and to improve financial self-efficacy in consumers, financial socialisation experiences such as offering encouragement to open a bank account, to save and invest money, and presenting opportunities to practise financial skills, may increase consumers’ self-efficacy and lead to positive financial behaviours. , Thesis (MCom) -- Faculty of Commerce, Management, 2022
- Full Text:
- Date Issued: 2022-04-06
- Authors: Maswena, Kaelo
- Date: 2022-04-06
- Subjects: Financial literacy South Africa , Finance, Personal South Africa , Budgets, Personal South Africa , Consumer behavior South Africa , Consumers Attitudes , Life skills South Africa , Social learning South Africa , Self-control South Africa , Socialization South Africa , Financial socialisation agents
- Language: English
- Type: Master's thesis , text
- Identifier: http://hdl.handle.net/10962/232421 , vital:49990
- Description: There is a need to promote positive financial behaviour in South Africa. According to the Human Sciences Research Council (2018), South African financial behaviour culture emphasises a financially vulnerable nation in terms of not having enough income for future planning and lacking financial self-control. In its key role in influencing financial behaviour, financial socialisation, which is characterised by interactions with indirect, or purposive financial education and communication of financial norms influencing financial behaviours, attitudes, knowledge, capabilities, and self-efficacy of consumers, is the topic of this study. The purpose of the study was to investigate the influence of financial socialisation agents on financial (actual and self-assessed) knowledge, financial self-efficacy and financial behaviour among South African consumers. Based on Glenn’s (2018) framework, Xiao et al. (2009) socialisation and Moschis et al. (1978) consumer socialisation theory, the financial socialisation theoretical framework is provided for this study. Literature review provided an overview of past studies on the concepts of financial socialisation, financial (actual and self-assessed) knowledge, financial self-efficacy and financial behaviour. Therefore, a positivistic research paradigm was adopted, which used a cross-sectional correlational research methodology. This study analysed data primarily collected by a questionnaire survey of South African social attitudes to financial literacy by the Human Sciences Research Council (2011), using a multi-staged sampling technique in all South African provinces of consumers of 16 years and older. Descriptive statistics showed that most respondents were black African females between the ages of 26 and 35 years. Most held Matric certificates and were in paid employment for 30 hours or more per week. Most respondents considered family to be the most influential financial socialisation agent, followed by friends, then the bank. Actual financial knowledge of respondents, was indicated as relatively high. Results on self-assessed financial knowledge showed that most of the respondents considered their level of financial knowledge to be neutral. Using Pearson product-moment correlations to measure the strength and correlations of relationships, positive significant correlations were found between financial socialisation agents, financial (actual and self-assessed) knowledge and financial self-efficacy, while a negative and insignificant correlation was found between financial socialisation agents and financial behaviour. Multiple regression analysis results testing the hypotheses of the study demonstrated that financial socialisation agents have a significant positive influence on financial (actual and self-assessed) knowledge and financial self-efficacy; a significant influence on financial behaviour was not reported. Self-assessed financial knowledge showed a positive significant influence on financial self-efficacy and actual financial knowledge had an insignificant negative influence on financial self-efficacy. Actual financial knowledge had a significant positive influence on financial behaviour, whereby a positive yet insignificant relationship was found between self-assessed knowledge and financial behaviour. In the end, recommendations for the results indicate that financial educators need to develop a financial education plan that will include other content areas of financial knowledge such as identified by Huston (2010) and Lusardi and Mitchell (2011); the most important recommendation would be to help consumers have an accurate understanding of their own level of financial knowledge and to improve financial self-efficacy in consumers, financial socialisation experiences such as offering encouragement to open a bank account, to save and invest money, and presenting opportunities to practise financial skills, may increase consumers’ self-efficacy and lead to positive financial behaviours. , Thesis (MCom) -- Faculty of Commerce, Management, 2022
- Full Text:
- Date Issued: 2022-04-06
The effects of temperature and exploitation on the behaviour of red roman Chrysoblephus laticeps (Sparidae) at baited video stations
- Authors: Mataboge, Bontle Boitumelo
- Date: 2022-04-06
- Subjects: Marine resources conservation South Africa Agulhas , Sparidae Effect of temperature on South Africa Agulhas , Sparidae Climatic factors South Africa Agulhas , Sparidae Effect of fishing on South Africa Agulhas , Sparidae Effect of human beings on South Africa Agulhas , Sparidae Behavior South Africa Agulhas , Overfishing South Africa Agulhas , Underwater videography in wildlife monitoring South Africa Agulhas , Red roman (Chrysoblephus laticeps)
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/291140 , vital:56823
- Description: Marine environments are experiencing rapidly increasing temperatures, sea levels and acidification and higher frequencies and magnitudes of extreme weather events as a result of climate change. In the Agulhas Ecoregion of South Africa, there has been an increase in the frequency and intensity of upwelling events. Upwelling events result in rapid and large decreases in water temperature which can persist for several days. Variation in water temperature is known to impact the metabolic rate of fish (which are ectotherms) and in turn their activity patterns. To promote fitness related traits, the metabolic rate of fish is maximised at a specific temperature range. Outside of this optimal temperature range, the capacity of fish to perform aerobically declines. Therefore, it is expected that an increase in upwelling may place the fish under significant physiological stress. The effects of climate change can be compounded by the effects of fisheries-induced evolution; the microevolution of a fish population due to the artificial selection of certain biological traits by fishing practices. Passive fishing gears preferentially remove large (older) and bold individuals, causing reductions in population size, genetic diversity and fecundity as well as size and age truncation and the loss of large, bold and dominant phenotypes in fish populations. These demographic changes affect the adaptive capacity of fish and exploited populations are expected to be less resilient to climate variability and long-term temperature change. The resilience of fish is largely dependent on their physiological attributes, particularly their metabolic rate. Theoretically, fish with broader aerobic scope (defined as the difference between an individual’s maximum metabolic rate and standard metabolic rate) will be more tolerant to the impacts of climate change as they have energy available for adaptation. Recent respirometry and accelerometry studies suggest that populations of the endemic southern African linefish Chrysoblephus laticeps (red roman) from inside marine protected areas (MPAs) have higher metabolic rates and broader aerobic scope compared to those found outside of MPAs, particularly at thermal extremes. As C. laticeps are highly resident it is possible that fish populations protected within well-established MPAs may be more resilient to the physiological stresses caused by upwelling if they are able to maintain their activity levels despite changing temperatures. Behaviour is a proxy that can be used to infer metabolism as behaviours have associated metabolic costs and benefits. Behaviour is also a trait that can be altered by passive fishing practices which preferentially extract more active and bold individuals. Given this context, the aim of this thesis was to determine the effects of short-term thermal variability on the population structure and behaviour of C. laticeps and whether these effects differed between protected and exploited populations. Baited remote underwater stereo-video systems (stereo-BRUVs) were used to observe C. laticeps inside two MPAs (Tsitsikamma and Goukamma) and at two exploited sites (Port Elizabeth and Cape St. Francis) over the temperature range 10-18 °C. The relative abundance, size and relevant behaviours of C. laticeps were recorded. The relative abundance (MaxN) of C. laticeps was not significantly higher inside the MPAs compared to the exploited sites. The size of C. laticeps did not vary significantly by protection level either. However, the mean size of C. laticeps was considerably smaller at Port Elizabeth compared to the three other locations. There was a notable absence of large C. laticeps size classes at Port Elizabeth. The effect of water temperature on relative abundance was only seen in the exploited areas, where temperature and abundance were positively correlated. This was not the case in the protected areas where C. laticeps abundance remained roughly consistent. Generally, the effect of temperature on all measured behaviours was consistent across protection levels. An exception was that the feeding rate at Tsitsikamma MPA was significantly higher than at Cape St. Francis at temperatures below 11.5 °C. Temperature had a significant effect on the time taken for the first individual to appear in the field of view. This time shortened with increasing temperature, regardless of protection level. This was likely a result of the metabolic constraints placed on individuals by low waters temperatures and individuals would be able to pursue the bait more readily at higher temperatures. However, there was no evidence of greater metabolic scope from the C. laticeps individuals observed in the MPAs, relative to the exploited areas. Individual size and the presence of conspecifics were also found to significantly influence behaviour. Generally, size had a positive relationship with behaviour, with larger individuals more likely to feed on the bait, chase other fish from the bait (only in the MPAs) and spend more time in the field of view. The higher displays of aggression in MPAs may be an indication of fishing practices having removed bold and dominant individuals at the exploited sites. The probability of fleeing and the feeding rates of individuals increased with increasing numbers of conspecifics, suggesting that C. laticeps behaviour is influenced by intraspecific competition. Overall, this thesis did not find strong evidence that C. laticeps from MPAs performed better than C. laticeps from exploited areas, even at low temperatures. Behavioural responses to temperature were highly variable across locations and this may be attributed to high behavioural phenotypic diversity among individuals. Environmental stressors, such as temperature changes, can illicit very different behavioural responses among individuals in a population. It is also possible that C. laticeps from the exploited areas have the same genetic predispositions to physiological stress as the individuals in the MPAs due to spillover and larval recruitment from the MPAs. Indeed, genetic studies find that all C. laticeps population in South African represent a single well-mixed genetic stock. It is likely that greater sampling effort is required to resolve the patterns in behaviour between exploited and protected populations. Nonetheless, given the influence of size on behaviour, the smaller size of C. laticeps at Port Elizabeth may be cause for concern regarding the vulnerability of future populations to ongoing climate change. , Thesis (MSc) -- Faculty of Science, Ichthyology and Fisheries Science, 2022
- Full Text:
- Date Issued: 2022-04-06
- Authors: Mataboge, Bontle Boitumelo
- Date: 2022-04-06
- Subjects: Marine resources conservation South Africa Agulhas , Sparidae Effect of temperature on South Africa Agulhas , Sparidae Climatic factors South Africa Agulhas , Sparidae Effect of fishing on South Africa Agulhas , Sparidae Effect of human beings on South Africa Agulhas , Sparidae Behavior South Africa Agulhas , Overfishing South Africa Agulhas , Underwater videography in wildlife monitoring South Africa Agulhas , Red roman (Chrysoblephus laticeps)
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/291140 , vital:56823
- Description: Marine environments are experiencing rapidly increasing temperatures, sea levels and acidification and higher frequencies and magnitudes of extreme weather events as a result of climate change. In the Agulhas Ecoregion of South Africa, there has been an increase in the frequency and intensity of upwelling events. Upwelling events result in rapid and large decreases in water temperature which can persist for several days. Variation in water temperature is known to impact the metabolic rate of fish (which are ectotherms) and in turn their activity patterns. To promote fitness related traits, the metabolic rate of fish is maximised at a specific temperature range. Outside of this optimal temperature range, the capacity of fish to perform aerobically declines. Therefore, it is expected that an increase in upwelling may place the fish under significant physiological stress. The effects of climate change can be compounded by the effects of fisheries-induced evolution; the microevolution of a fish population due to the artificial selection of certain biological traits by fishing practices. Passive fishing gears preferentially remove large (older) and bold individuals, causing reductions in population size, genetic diversity and fecundity as well as size and age truncation and the loss of large, bold and dominant phenotypes in fish populations. These demographic changes affect the adaptive capacity of fish and exploited populations are expected to be less resilient to climate variability and long-term temperature change. The resilience of fish is largely dependent on their physiological attributes, particularly their metabolic rate. Theoretically, fish with broader aerobic scope (defined as the difference between an individual’s maximum metabolic rate and standard metabolic rate) will be more tolerant to the impacts of climate change as they have energy available for adaptation. Recent respirometry and accelerometry studies suggest that populations of the endemic southern African linefish Chrysoblephus laticeps (red roman) from inside marine protected areas (MPAs) have higher metabolic rates and broader aerobic scope compared to those found outside of MPAs, particularly at thermal extremes. As C. laticeps are highly resident it is possible that fish populations protected within well-established MPAs may be more resilient to the physiological stresses caused by upwelling if they are able to maintain their activity levels despite changing temperatures. Behaviour is a proxy that can be used to infer metabolism as behaviours have associated metabolic costs and benefits. Behaviour is also a trait that can be altered by passive fishing practices which preferentially extract more active and bold individuals. Given this context, the aim of this thesis was to determine the effects of short-term thermal variability on the population structure and behaviour of C. laticeps and whether these effects differed between protected and exploited populations. Baited remote underwater stereo-video systems (stereo-BRUVs) were used to observe C. laticeps inside two MPAs (Tsitsikamma and Goukamma) and at two exploited sites (Port Elizabeth and Cape St. Francis) over the temperature range 10-18 °C. The relative abundance, size and relevant behaviours of C. laticeps were recorded. The relative abundance (MaxN) of C. laticeps was not significantly higher inside the MPAs compared to the exploited sites. The size of C. laticeps did not vary significantly by protection level either. However, the mean size of C. laticeps was considerably smaller at Port Elizabeth compared to the three other locations. There was a notable absence of large C. laticeps size classes at Port Elizabeth. The effect of water temperature on relative abundance was only seen in the exploited areas, where temperature and abundance were positively correlated. This was not the case in the protected areas where C. laticeps abundance remained roughly consistent. Generally, the effect of temperature on all measured behaviours was consistent across protection levels. An exception was that the feeding rate at Tsitsikamma MPA was significantly higher than at Cape St. Francis at temperatures below 11.5 °C. Temperature had a significant effect on the time taken for the first individual to appear in the field of view. This time shortened with increasing temperature, regardless of protection level. This was likely a result of the metabolic constraints placed on individuals by low waters temperatures and individuals would be able to pursue the bait more readily at higher temperatures. However, there was no evidence of greater metabolic scope from the C. laticeps individuals observed in the MPAs, relative to the exploited areas. Individual size and the presence of conspecifics were also found to significantly influence behaviour. Generally, size had a positive relationship with behaviour, with larger individuals more likely to feed on the bait, chase other fish from the bait (only in the MPAs) and spend more time in the field of view. The higher displays of aggression in MPAs may be an indication of fishing practices having removed bold and dominant individuals at the exploited sites. The probability of fleeing and the feeding rates of individuals increased with increasing numbers of conspecifics, suggesting that C. laticeps behaviour is influenced by intraspecific competition. Overall, this thesis did not find strong evidence that C. laticeps from MPAs performed better than C. laticeps from exploited areas, even at low temperatures. Behavioural responses to temperature were highly variable across locations and this may be attributed to high behavioural phenotypic diversity among individuals. Environmental stressors, such as temperature changes, can illicit very different behavioural responses among individuals in a population. It is also possible that C. laticeps from the exploited areas have the same genetic predispositions to physiological stress as the individuals in the MPAs due to spillover and larval recruitment from the MPAs. Indeed, genetic studies find that all C. laticeps population in South African represent a single well-mixed genetic stock. It is likely that greater sampling effort is required to resolve the patterns in behaviour between exploited and protected populations. Nonetheless, given the influence of size on behaviour, the smaller size of C. laticeps at Port Elizabeth may be cause for concern regarding the vulnerability of future populations to ongoing climate change. , Thesis (MSc) -- Faculty of Science, Ichthyology and Fisheries Science, 2022
- Full Text:
- Date Issued: 2022-04-06
The invasion autecology of Iris pseudacorus L. (Iridaceae) in South Africa
- Authors: Sandenbergh, Emma
- Date: 2022-04-06
- Subjects: Iris pseudacorus South Africa , Invasive plants South Africa , Aquatic weeds South Africa , Plant genetics South Africa , Freshwater ecology South Africa , Iris pseudacorus Geographical distribution , Phytogeography
- Language: English
- Type: Master's thesis , text
- Identifier: http://hdl.handle.net/10962/232272 , vital:49977
- Description: Iris pseudacorus L. (Iridaceae) is an emergent aquatic macrophyte originating from Europe, north Africa, and western Asia, and is becoming an increasingly problematic invader in South Africa. By forming dense rhizomatic mats in the absence of natural enemies, I. pseudacorus outcompetes co-occurring indigenous biota, causing serious environmental and socioeconomic challenges. Iris pseudacorus is a declared invader in South Africa, Argentina, New Zealand, the United States of America, and Canada, but little information is known regarding the species’ invasive potential, particularly in the southern hemisphere, hindering the effectiveness of control efforts. This study addresses this knowledge gap in a South African context, providing valuable insight into the invasion autecology of I. pseudacorus in South Africa. For effective management and control of I. pseudacorus in South Africa and the global south, its distribution and invasive potential must be determined, and its population genetics understood. Hence, this study aimed to map the current confirmed distribution of I. pseudacorus populations in South Africa, investigating the relative abundance of I. pseudacorus individuals in each population, and comparing their sexual reproductive outputs. Moreover, this study assessed the competitive interactions between I. pseudacorus and co-occurring native species T. capensis, and examined the genetic diversity present between and within South African I. pseudacorus populations. Through field surveys, I. pseudacorus infestations were confirmed in eight of the country’s nine provinces, with the highest number of infestations recorded in the urban hubs, and greatest population abundances reported in the warmer, wetter regions of South Africa. These surveys indicated that South African I. pseudacorus populations have enhanced their sexual reproductive output relative to native range populations, and a germination rate of ~ 83 % was determined in the laboratory. The results of a common garden competition experiment indicated that T. capensis may be a superior competitor over I. pseudacorus, but this was not supported by field observations, and may be a result of the short duration of the experiment. Using inter-simple sequence repeats (ISSRs), high genetic diversity was observed within and between populations of I. pseudacorus, indicating the employment of sexual reproductive strategies, and providing evidence for gene-flow between and within populations. Moreover, a weak negative correlation was observed between geographic distance and genetic similarity, ii indicating a largely anthropogenic spread of I. pseudacorus, and suggesting the occurrence of fewer founding events than reported in the United States. This study provides useful insight into the invasion autecology of I. pseudacorus in South Africa, contributing to the ongoing research surrounding I. pseudacorus invasions worldwide, particularly in the southern hemisphere. These results contribute to the development of appropriate adaptive and integrated management strategies to control I. pseudacorus invasions in South Africa, and should be implemented before South African I. pseudacorus infestations reach the severity observed elsewhere. , Thesis (MSc) -- Faculty of Science, Botany, 2022
- Full Text:
- Date Issued: 2022-04-06
- Authors: Sandenbergh, Emma
- Date: 2022-04-06
- Subjects: Iris pseudacorus South Africa , Invasive plants South Africa , Aquatic weeds South Africa , Plant genetics South Africa , Freshwater ecology South Africa , Iris pseudacorus Geographical distribution , Phytogeography
- Language: English
- Type: Master's thesis , text
- Identifier: http://hdl.handle.net/10962/232272 , vital:49977
- Description: Iris pseudacorus L. (Iridaceae) is an emergent aquatic macrophyte originating from Europe, north Africa, and western Asia, and is becoming an increasingly problematic invader in South Africa. By forming dense rhizomatic mats in the absence of natural enemies, I. pseudacorus outcompetes co-occurring indigenous biota, causing serious environmental and socioeconomic challenges. Iris pseudacorus is a declared invader in South Africa, Argentina, New Zealand, the United States of America, and Canada, but little information is known regarding the species’ invasive potential, particularly in the southern hemisphere, hindering the effectiveness of control efforts. This study addresses this knowledge gap in a South African context, providing valuable insight into the invasion autecology of I. pseudacorus in South Africa. For effective management and control of I. pseudacorus in South Africa and the global south, its distribution and invasive potential must be determined, and its population genetics understood. Hence, this study aimed to map the current confirmed distribution of I. pseudacorus populations in South Africa, investigating the relative abundance of I. pseudacorus individuals in each population, and comparing their sexual reproductive outputs. Moreover, this study assessed the competitive interactions between I. pseudacorus and co-occurring native species T. capensis, and examined the genetic diversity present between and within South African I. pseudacorus populations. Through field surveys, I. pseudacorus infestations were confirmed in eight of the country’s nine provinces, with the highest number of infestations recorded in the urban hubs, and greatest population abundances reported in the warmer, wetter regions of South Africa. These surveys indicated that South African I. pseudacorus populations have enhanced their sexual reproductive output relative to native range populations, and a germination rate of ~ 83 % was determined in the laboratory. The results of a common garden competition experiment indicated that T. capensis may be a superior competitor over I. pseudacorus, but this was not supported by field observations, and may be a result of the short duration of the experiment. Using inter-simple sequence repeats (ISSRs), high genetic diversity was observed within and between populations of I. pseudacorus, indicating the employment of sexual reproductive strategies, and providing evidence for gene-flow between and within populations. Moreover, a weak negative correlation was observed between geographic distance and genetic similarity, ii indicating a largely anthropogenic spread of I. pseudacorus, and suggesting the occurrence of fewer founding events than reported in the United States. This study provides useful insight into the invasion autecology of I. pseudacorus in South Africa, contributing to the ongoing research surrounding I. pseudacorus invasions worldwide, particularly in the southern hemisphere. These results contribute to the development of appropriate adaptive and integrated management strategies to control I. pseudacorus invasions in South Africa, and should be implemented before South African I. pseudacorus infestations reach the severity observed elsewhere. , Thesis (MSc) -- Faculty of Science, Botany, 2022
- Full Text:
- Date Issued: 2022-04-06
Antimalarial activity of quinoline thiosemicarbazones: synthesis and antiplasmodial evaluation
- Nqeno, Lukhanyiso Khanyisile
- Authors: Nqeno, Lukhanyiso Khanyisile
- Date: 2022-04-06
- Subjects: Antimalarials , Quinoline , Thiosemicarbazones , Malaria Chemotherapy , Plasmodium falciparum , Malaria Africa, Sub-Saharan , Iron chelates Therapeutic use
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/291292 , vital:56841
- Description: Africa is one of the regions that is most affected by malaria, as 90% of all malaria deaths occur in sub-saharan Africa. Malaria is a life threatening disease responsible for an estimated 800000 deaths each year, the majority of these deaths occurred in children under the age of five. The disease is a mosquito-borne, and it is transmitted to humans by the female Anopheles mosquito. The parasite responsible for this disease belong to the Plasmodium genus with Plasmodium falciparum causing the most severe cases of the disease in humans. The most widely available anti-malarials were designed to specifically target the pathogenic blood stage in humans, however, in order to completely eradicate malaria there is a need for the development of medicines that not only target the pathogenic blood stage of the parasite but also block parasite transmission and eliminate asymptomatic and cryptic hepatic forms of the parasite. Iron chelators have recently gained importance as potent antimalarials, to cause infection nearly all protozoa obtain growth essential iron from their hosts. Iron is required for the development of the parasite. Deprivation of utilizable iron by chelation is a proficient approach to arrest parasite growth and associated infection. Thiosemicarbazones are known iron chelating agents by bonding through the sulfur and azomethine nitrogen atoms. This study is aimed at the identification of thiosemicarbazone based derivatives as possible antimalarial agents. Due to their iron chelation abilities there has been increasing interest in the investigation of thiosemicarbazones as possible antimalarials. During the course of this project, several thiosemicarbazone derivatives were synthesized and their structure confirmed using routine analytical techniques (NMR, FTIR, and HRMS). The synthesized compounds were evaluated in vitro against the chloroquine sensitive strain (3D7) of P. falciparum for antimarial activity. The compounds were also evaluated agsinst Hela cells for overt cytotoxicity. The compounds generally showed poor antimalarial activity. One compound (LKN11) was identified to possess intrinsic and moderate antimalarial activity of 6.6 μM. The compounds were generally not cytotoxic against Hela cell at concentrations of up to 20 μM, with only compound LKN10 showing modest cytotoxic activity of 9.5 μM. This research went on to identify two thiosemicarbazone based derivatives which had a significant effect on HeLa and pLDH cells. , Thesis (MSc) -- Faculty of Science, Chemistry, 2022
- Full Text:
- Date Issued: 2022-04-06
- Authors: Nqeno, Lukhanyiso Khanyisile
- Date: 2022-04-06
- Subjects: Antimalarials , Quinoline , Thiosemicarbazones , Malaria Chemotherapy , Plasmodium falciparum , Malaria Africa, Sub-Saharan , Iron chelates Therapeutic use
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/291292 , vital:56841
- Description: Africa is one of the regions that is most affected by malaria, as 90% of all malaria deaths occur in sub-saharan Africa. Malaria is a life threatening disease responsible for an estimated 800000 deaths each year, the majority of these deaths occurred in children under the age of five. The disease is a mosquito-borne, and it is transmitted to humans by the female Anopheles mosquito. The parasite responsible for this disease belong to the Plasmodium genus with Plasmodium falciparum causing the most severe cases of the disease in humans. The most widely available anti-malarials were designed to specifically target the pathogenic blood stage in humans, however, in order to completely eradicate malaria there is a need for the development of medicines that not only target the pathogenic blood stage of the parasite but also block parasite transmission and eliminate asymptomatic and cryptic hepatic forms of the parasite. Iron chelators have recently gained importance as potent antimalarials, to cause infection nearly all protozoa obtain growth essential iron from their hosts. Iron is required for the development of the parasite. Deprivation of utilizable iron by chelation is a proficient approach to arrest parasite growth and associated infection. Thiosemicarbazones are known iron chelating agents by bonding through the sulfur and azomethine nitrogen atoms. This study is aimed at the identification of thiosemicarbazone based derivatives as possible antimalarial agents. Due to their iron chelation abilities there has been increasing interest in the investigation of thiosemicarbazones as possible antimalarials. During the course of this project, several thiosemicarbazone derivatives were synthesized and their structure confirmed using routine analytical techniques (NMR, FTIR, and HRMS). The synthesized compounds were evaluated in vitro against the chloroquine sensitive strain (3D7) of P. falciparum for antimarial activity. The compounds were also evaluated agsinst Hela cells for overt cytotoxicity. The compounds generally showed poor antimalarial activity. One compound (LKN11) was identified to possess intrinsic and moderate antimalarial activity of 6.6 μM. The compounds were generally not cytotoxic against Hela cell at concentrations of up to 20 μM, with only compound LKN10 showing modest cytotoxic activity of 9.5 μM. This research went on to identify two thiosemicarbazone based derivatives which had a significant effect on HeLa and pLDH cells. , Thesis (MSc) -- Faculty of Science, Chemistry, 2022
- Full Text:
- Date Issued: 2022-04-06
The use of the cochineal insect, Dactylopius tomentosus Lamarck, as a biological control agent for the invasive alien thistle cholla, Cylindropuntia pallida (Rose) F.M. Knuth in South Africa
- Authors: Zozo, Ekhona
- Date: 2022-04-06
- Subjects: Cochineal insect , Thistles Biological control South Africa , Alien plants South Africa , Invasive plants South Africa , Cactus South Africa , Biological assay
- Language: English
- Type: Master's thesis , text
- Identifier: http://hdl.handle.net/10962/233823 , vital:50131
- Description: Cylindropuntia pallida (Rose) F.M. Knuth (Cactaceae) is an invasive alien plant in South Africa indigenous in the southern U.S.A. and Mexico. Large infestations of this species can be found in the Kalahari and arid Karoo regions of South Africa, which is also present in Namibia. Because it is a very spiny cactus, dense infestations have a negative impact on agriculture and natural ecosystems. This cactus has become naturalised to the extent that eradication is impossible and the negative impacts are steadily increasing due to its increasing distribution and density. The cochineal insect, Dactylopius tomentosus Lamarck (Dactylopiidae), is native in Mexico and parts of North America, such as Texas, Arizona, and New Mexico in the U.S.A. This cochineal species is highly specialized and associated only with Cylindropuntia species, a group of cacti that are primarily restricted to the same areas. It has been introduced into Australia and South Africa as a biological control agent to control various invasive alien Cylindropuntia species. This cochineal species has several biotypes specific to certain Cylindropuntia species hosts. A biotype is a clade that cannot be differentiated morphologically from others but has different host ranges and impacts depending on the host plant species. Included amongst biotypes that have been released in South Africa are D. tomentosus ‘imbricata’ and D. tomentosus ‘cholla’ for the biological control of Cylindropuntia imbricata (Haw.) F.M. Knuth (Cactaceae) and Cylindropuntia fulgida (Engelmann) F.M. Knuth var. mamillata (Schott ex Engelmann) Backeb. (Cactaceae), respectively. These biotypes have resulted in both host plants being under substantial control in South Africa. The first part of this thesis evaluated which of the two D. tomentosus biotypes already in use in South Africa could be an effective biological control agent for C. pallida. This was done by assessing the fitness of the cochineals on the three cactus species and assessing the impact that each of the cochineals has on each of the target weed species. Should these biotypes prove ineffective, there is a third biotype, namely D. tomentosus ‘californica var. parkerii’, which researchers in Australia have worked on and have found to be suitably host-specific for release in Australia and suitably damaging to C. pallida in that country. Therefore, this new biotype could be released in South Africa if it is required. Sexually compatible biological control agents, especially those closely related and occurring in close spatial proximity to one another, may interbreed and the impacts of this hybridisation are difficult to predict. It is important to understand the outcomes of the hybridisation of cochineal because it can affect the impact of the biological control agents and thus the control of the target weed. The second part of this thesis investigated the impacts of the hybridisation of the two cochineal biotypes by assessing the damage the agents would have on the target weed, and on C. imbricata and C. fulgida var. mamillata, in the presence of one or both cochineal biotypes. The ‘cholla’ biotype performed better on C. pallida than the ‘imbricata’ biotype, but neither biotype could control C. pallida to an extent similar to the control they provide for their respective target weeds, C. imbricata and C. fulgida var. mamillata. Both the ‘cholla’ biotype and hybrids of the two biotypes of cochineal were effective at killing C. pallida when both C. imbricata and C. fulgida var. mamillata were also present. This suggests that the ‘cholla’ or hybrids may be effective at controlling C. pallida when either C. imbricata or C. fulgida var. mamillata are also present in the field due to the high population density of cochineal that results under these circumstances. There are, however, many C. pallida infestations in South Africa where the plant is problematic and is isolated from other Cylindropuntia species, and these populations are unlikely to be controlled by the ‘cholla’ biotype or the hybrids. Neither of the cochineal biotypes that are used for biological control in South Africa are suitably damaging to C. pallida to warrant their use as biological control agents for this species. Dactylopius tomentosus ‘californica var. parkerii’ is therefore recommended for release based on its host-specificity and impact to C. pallida in Australia. , Thesis (PhD) -- Faculty of Science, Zoology and Entomology, 2022
- Full Text:
- Date Issued: 2022-04-06
- Authors: Zozo, Ekhona
- Date: 2022-04-06
- Subjects: Cochineal insect , Thistles Biological control South Africa , Alien plants South Africa , Invasive plants South Africa , Cactus South Africa , Biological assay
- Language: English
- Type: Master's thesis , text
- Identifier: http://hdl.handle.net/10962/233823 , vital:50131
- Description: Cylindropuntia pallida (Rose) F.M. Knuth (Cactaceae) is an invasive alien plant in South Africa indigenous in the southern U.S.A. and Mexico. Large infestations of this species can be found in the Kalahari and arid Karoo regions of South Africa, which is also present in Namibia. Because it is a very spiny cactus, dense infestations have a negative impact on agriculture and natural ecosystems. This cactus has become naturalised to the extent that eradication is impossible and the negative impacts are steadily increasing due to its increasing distribution and density. The cochineal insect, Dactylopius tomentosus Lamarck (Dactylopiidae), is native in Mexico and parts of North America, such as Texas, Arizona, and New Mexico in the U.S.A. This cochineal species is highly specialized and associated only with Cylindropuntia species, a group of cacti that are primarily restricted to the same areas. It has been introduced into Australia and South Africa as a biological control agent to control various invasive alien Cylindropuntia species. This cochineal species has several biotypes specific to certain Cylindropuntia species hosts. A biotype is a clade that cannot be differentiated morphologically from others but has different host ranges and impacts depending on the host plant species. Included amongst biotypes that have been released in South Africa are D. tomentosus ‘imbricata’ and D. tomentosus ‘cholla’ for the biological control of Cylindropuntia imbricata (Haw.) F.M. Knuth (Cactaceae) and Cylindropuntia fulgida (Engelmann) F.M. Knuth var. mamillata (Schott ex Engelmann) Backeb. (Cactaceae), respectively. These biotypes have resulted in both host plants being under substantial control in South Africa. The first part of this thesis evaluated which of the two D. tomentosus biotypes already in use in South Africa could be an effective biological control agent for C. pallida. This was done by assessing the fitness of the cochineals on the three cactus species and assessing the impact that each of the cochineals has on each of the target weed species. Should these biotypes prove ineffective, there is a third biotype, namely D. tomentosus ‘californica var. parkerii’, which researchers in Australia have worked on and have found to be suitably host-specific for release in Australia and suitably damaging to C. pallida in that country. Therefore, this new biotype could be released in South Africa if it is required. Sexually compatible biological control agents, especially those closely related and occurring in close spatial proximity to one another, may interbreed and the impacts of this hybridisation are difficult to predict. It is important to understand the outcomes of the hybridisation of cochineal because it can affect the impact of the biological control agents and thus the control of the target weed. The second part of this thesis investigated the impacts of the hybridisation of the two cochineal biotypes by assessing the damage the agents would have on the target weed, and on C. imbricata and C. fulgida var. mamillata, in the presence of one or both cochineal biotypes. The ‘cholla’ biotype performed better on C. pallida than the ‘imbricata’ biotype, but neither biotype could control C. pallida to an extent similar to the control they provide for their respective target weeds, C. imbricata and C. fulgida var. mamillata. Both the ‘cholla’ biotype and hybrids of the two biotypes of cochineal were effective at killing C. pallida when both C. imbricata and C. fulgida var. mamillata were also present. This suggests that the ‘cholla’ or hybrids may be effective at controlling C. pallida when either C. imbricata or C. fulgida var. mamillata are also present in the field due to the high population density of cochineal that results under these circumstances. There are, however, many C. pallida infestations in South Africa where the plant is problematic and is isolated from other Cylindropuntia species, and these populations are unlikely to be controlled by the ‘cholla’ biotype or the hybrids. Neither of the cochineal biotypes that are used for biological control in South Africa are suitably damaging to C. pallida to warrant their use as biological control agents for this species. Dactylopius tomentosus ‘californica var. parkerii’ is therefore recommended for release based on its host-specificity and impact to C. pallida in Australia. , Thesis (PhD) -- Faculty of Science, Zoology and Entomology, 2022
- Full Text:
- Date Issued: 2022-04-06
The role of a national system of innovation in facilitating development in South Africa from a comparative BRICS perspective
- Authors: Sibhukwana, Andiswa
- Date: 2022-04-06
- Subjects: BRIC countries , Technological innovations Economic aspects South Africa , Economic development South Africa , Economics Mathematical models , Neoclassical school of economics , South Africa Economic conditions , South Africa Economic policy , National systems of innovation
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/284616 , vital:56079
- Description: The aim of the dissertation was to investigate whether the adoption of a national system of innovation has helped facilitate development in South Africa from a comparative BRICS perspective. South Africa has an expanding focus on science and technology, as per the Science and Technology White Paper (1996). There appeared to be innovation that had left out much of the citizenry. There continued to be poverty, inequality, and joblessness. The study aimed to understand how the NSI approach could be used to foster inclusive and transformative development. The study used a mixed-methods approach. The qualitative aspect of the research focused on an innovation and public policy study which assessed the various policies and initiatives implemented in each of the BRICS countries to drive innovation and foster development. The qualitative aspect of the study found that the innovation paradigm required governments to adopt a more holistic approach to public policy design and analysis. The quantitative aspect of the research focused on a trend, correlation, and regression analysis. The trend analysis revealed that China and Brazil increased their allocation of resources towards R&D compared to the other countries. Brazil is regarded as a social investment state, while China is a developmental state: this means the state plays an extraordinarily strong coordinative and financing role in the NSI. On the other hand, the correlation matrix for South Africa revealed a statistically significant positive linear association between various NSI indicators and human development. This suggested that the innovation benefits are trickling down to the general citizenry. In essence the study articulated key elements of the understanding of current and potential impacts of technological change in productivity and growth, employment and inequality that can be used for policy making. , Thesis (MEcon) -- Faculty of Commerce, Economics and Economic History, 2022
- Full Text:
- Date Issued: 2022-04-06
- Authors: Sibhukwana, Andiswa
- Date: 2022-04-06
- Subjects: BRIC countries , Technological innovations Economic aspects South Africa , Economic development South Africa , Economics Mathematical models , Neoclassical school of economics , South Africa Economic conditions , South Africa Economic policy , National systems of innovation
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/284616 , vital:56079
- Description: The aim of the dissertation was to investigate whether the adoption of a national system of innovation has helped facilitate development in South Africa from a comparative BRICS perspective. South Africa has an expanding focus on science and technology, as per the Science and Technology White Paper (1996). There appeared to be innovation that had left out much of the citizenry. There continued to be poverty, inequality, and joblessness. The study aimed to understand how the NSI approach could be used to foster inclusive and transformative development. The study used a mixed-methods approach. The qualitative aspect of the research focused on an innovation and public policy study which assessed the various policies and initiatives implemented in each of the BRICS countries to drive innovation and foster development. The qualitative aspect of the study found that the innovation paradigm required governments to adopt a more holistic approach to public policy design and analysis. The quantitative aspect of the research focused on a trend, correlation, and regression analysis. The trend analysis revealed that China and Brazil increased their allocation of resources towards R&D compared to the other countries. Brazil is regarded as a social investment state, while China is a developmental state: this means the state plays an extraordinarily strong coordinative and financing role in the NSI. On the other hand, the correlation matrix for South Africa revealed a statistically significant positive linear association between various NSI indicators and human development. This suggested that the innovation benefits are trickling down to the general citizenry. In essence the study articulated key elements of the understanding of current and potential impacts of technological change in productivity and growth, employment and inequality that can be used for policy making. , Thesis (MEcon) -- Faculty of Commerce, Economics and Economic History, 2022
- Full Text:
- Date Issued: 2022-04-06
Molecular characterization of microbial communities in the Sundays and Swartkops estuaries impacted by anthropogenic activities
- Kgomokhumo, Tlhoafalang Evah
- Authors: Kgomokhumo, Tlhoafalang Evah
- Date: 2022-04-06
- Subjects: Microbial ecology South Africa Sundays Estuary (Eastern Cape) , Microbial ecology South Africa Swartkops River Estuary , Estuarine health Effect of human beings on South Africa Sundays Estuary (Eastern Cape) , Estuarine health Effect of human beings on South Africa Swartkops River Estuary , Microorganisms South Africa Sundays Estuary (Eastern Cape) Molecular aspects , Microorganisms South Africa Swartkops River Estuary Molecular aspects , Eutrophication South Africa Sundays Estuary (Eastern Cape) , Eutrophication South Africa Swartkops River Estuary , Algal blooms South Africa Sundays Estuary (Eastern Cape) , Algal blooms South Africa Swartkops River Estuary
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/290994 , vital:56806
- Description: Anthropogenic activities are of concern in estuarine systems as they are the main source of water degradation. Water pollution in estuaries is indicated by eutrophication and the presence of pathogens and bacterial indicators which affect biodiversity and energy flow. This study focused on two geographically linked estuaries, namely the Sundays and Swartkops Estuaries. The Sundays Estuary is primarily impacted by agricultural activities in the river catchment with increased nutrients levels, particularly of total oxidised nitrogen (TOxN), likely derived from these farming activities. In contrast, the Swartkops Estuary, which is heavily influenced by urban/industrial activities, reflected increased levels of phosphates likely from wastewater and sewage water contamination from residential areas, leaking pipes, and poorly managed sewage treatment plants. The central objective of this study was to assess microbial population profiles and diversity impacted by agricultural activities in Sundays Estuary and industrial/urban-influenced Swartkops Estuary using 16S and 18S rRNA gene metabarcoding. A distinct difference in eukaryotic composition and diversity was evident between the two sampling exercises in 2018 and 2019 in Sundays Estuary. The eutrophication of both the Sundays and Swartkops estuaries was evident in the repeated occurrences of bloom events. In the Sundays Estuary, a bloom of Heterosigma akashiwo was observed in 2018 whilst Cyclotella dominated the estuary in 2019. The Swartkops Estuary exhibited seasonal variation in phytoplankton composition with Bacillariophyceae blooms in the upper reaches of the estuary in summer and increased prevalence of Dinophyceae in spring. Bacterial taxonomic variation was also noted between the two contrasting estuaries. Although members of the Proteobacteria dominated both estuaries, Gammaproteobacteria were in increased abundance in Sundays Estuary while members of Alphaproteobacteria were in high relative abundance in the marine dominated Swartkops Estuary. Members of the Bacteroidetes were the second most abundant bacterial phylum in both estuaries. Bacterial indicators of agricultural anthropogenic impacts identified in Sundays Estuary included members of Sporichthyaceae, Erysipelotrichaceae, Nostocaceae, and NS11-12_marine_group while some taxa such as the Flavobacteriaceae, Cryomorphaceae, and Halieaceae reflected their capability in degrading the phytoplankton bloom biomass present in the estuary. The urban impacts on the Swartkops Estuary was reflected by the contamination of the estuary with potential pathogens including Aeromonas caviae, Vibrio fluvialis, Mycobacterium intracellulare, Vibrio cholerae, and Bacillus cereus. Bacterial community profiles of the major water inflow points into the Swartkops Estuary included members of the Burkholderiaceae, Rhodocyclaceae, Aeromonadaceae, and Arcobacteriaceae which are typically indicative of raw sewage contamination. The Motherwell canal, which runs through informal settlements, was the most polluted input source with high levels of anthropogenic nutrients and pathogenic bacteria. The Chatty river, which also runs through townships, recorded increased nutrient concentrations and low bacterial richness and diversity which was likely due to an Arthrospira bloom at the time of sampling. The overall results of this study identified sources of pollution in Sundays and Swartkops Estuaries and highlighted the impacts of anthropogenic inputs on microbial population profiles and diversity. , Thesis (MSc) -- Faculty of Science, Biochemistry and Microbiology, 2022
- Full Text:
- Date Issued: 2022-04-06
- Authors: Kgomokhumo, Tlhoafalang Evah
- Date: 2022-04-06
- Subjects: Microbial ecology South Africa Sundays Estuary (Eastern Cape) , Microbial ecology South Africa Swartkops River Estuary , Estuarine health Effect of human beings on South Africa Sundays Estuary (Eastern Cape) , Estuarine health Effect of human beings on South Africa Swartkops River Estuary , Microorganisms South Africa Sundays Estuary (Eastern Cape) Molecular aspects , Microorganisms South Africa Swartkops River Estuary Molecular aspects , Eutrophication South Africa Sundays Estuary (Eastern Cape) , Eutrophication South Africa Swartkops River Estuary , Algal blooms South Africa Sundays Estuary (Eastern Cape) , Algal blooms South Africa Swartkops River Estuary
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/290994 , vital:56806
- Description: Anthropogenic activities are of concern in estuarine systems as they are the main source of water degradation. Water pollution in estuaries is indicated by eutrophication and the presence of pathogens and bacterial indicators which affect biodiversity and energy flow. This study focused on two geographically linked estuaries, namely the Sundays and Swartkops Estuaries. The Sundays Estuary is primarily impacted by agricultural activities in the river catchment with increased nutrients levels, particularly of total oxidised nitrogen (TOxN), likely derived from these farming activities. In contrast, the Swartkops Estuary, which is heavily influenced by urban/industrial activities, reflected increased levels of phosphates likely from wastewater and sewage water contamination from residential areas, leaking pipes, and poorly managed sewage treatment plants. The central objective of this study was to assess microbial population profiles and diversity impacted by agricultural activities in Sundays Estuary and industrial/urban-influenced Swartkops Estuary using 16S and 18S rRNA gene metabarcoding. A distinct difference in eukaryotic composition and diversity was evident between the two sampling exercises in 2018 and 2019 in Sundays Estuary. The eutrophication of both the Sundays and Swartkops estuaries was evident in the repeated occurrences of bloom events. In the Sundays Estuary, a bloom of Heterosigma akashiwo was observed in 2018 whilst Cyclotella dominated the estuary in 2019. The Swartkops Estuary exhibited seasonal variation in phytoplankton composition with Bacillariophyceae blooms in the upper reaches of the estuary in summer and increased prevalence of Dinophyceae in spring. Bacterial taxonomic variation was also noted between the two contrasting estuaries. Although members of the Proteobacteria dominated both estuaries, Gammaproteobacteria were in increased abundance in Sundays Estuary while members of Alphaproteobacteria were in high relative abundance in the marine dominated Swartkops Estuary. Members of the Bacteroidetes were the second most abundant bacterial phylum in both estuaries. Bacterial indicators of agricultural anthropogenic impacts identified in Sundays Estuary included members of Sporichthyaceae, Erysipelotrichaceae, Nostocaceae, and NS11-12_marine_group while some taxa such as the Flavobacteriaceae, Cryomorphaceae, and Halieaceae reflected their capability in degrading the phytoplankton bloom biomass present in the estuary. The urban impacts on the Swartkops Estuary was reflected by the contamination of the estuary with potential pathogens including Aeromonas caviae, Vibrio fluvialis, Mycobacterium intracellulare, Vibrio cholerae, and Bacillus cereus. Bacterial community profiles of the major water inflow points into the Swartkops Estuary included members of the Burkholderiaceae, Rhodocyclaceae, Aeromonadaceae, and Arcobacteriaceae which are typically indicative of raw sewage contamination. The Motherwell canal, which runs through informal settlements, was the most polluted input source with high levels of anthropogenic nutrients and pathogenic bacteria. The Chatty river, which also runs through townships, recorded increased nutrient concentrations and low bacterial richness and diversity which was likely due to an Arthrospira bloom at the time of sampling. The overall results of this study identified sources of pollution in Sundays and Swartkops Estuaries and highlighted the impacts of anthropogenic inputs on microbial population profiles and diversity. , Thesis (MSc) -- Faculty of Science, Biochemistry and Microbiology, 2022
- Full Text:
- Date Issued: 2022-04-06
Academic or ‘zoombie’? Characterizing sleep quality, work and lifestyle behaviours among a cohort of South African academic staff during the Covid-19 pandemic
- Authors: Le Grange, Sarah-Ann
- Date: 2022-04-06
- Subjects: Sleep-wake cycle South Africa Eastern Cape , Sleep Physiological aspects , Lifestyles Health aspects South Africa Eastern Cape , COVID-19 Pandemic, 2020- Influence , Work environment Psychological aspects , Work environment Physiological aspects , College teachers Workload South Africa Eastern Cape , Pittsburgh Sleep Quality Index (PSQI)
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/291099 , vital:56818
- Description: Working in academe is characterized by high work demands, long and late working hours and balancing multiple roles. This often leaves academic staff (interchangeably referred to as ‘academics’ and ‘staff’) with limited time to prioritize adequate rest and sleep. While sufficient sleep is important for general well-being and work performance, it may be important for academics given the cognitive and interactive nature of their work. However, limited research has characterized sleep behaviours and sleep quality in academic staff globally and specifically in South Africa (SA). Further, research shows that academics from different academic ranks and genders differ in their work experiences but less is known about whether these factors affect their sleep and lifestyle factors. Over and above the demands of academic work, the current study was conducted during COVID-19, which saw unprecedented change in workloads for academic staff due to online teaching and learning. Additionally, the pandemic has been associated with poorer sleep quality and lifestyle behaviours in the general population, but very few studies have explored this in the context of academics. Thus, this study aimed to characterize the sleep quality, work and lifestyle factors among academics from a university in the Eastern Cape province of SA and determine the effects of gender and academic rank on these measures. Additionally, the study aimed to determine the impact of COVID-19 on sleep and work-related factors of this group. This study adopted a cross-sectional design and made use of an online questionnaire that was distributed to all academics employed at the institution via email. The data collection occurred over an 8-week testing period between August and September of 2020. The questionnaire explored sociodemographic, work and lifestyle characteristics, while the characteristics of sleep and sleep quality were explored with the Pittsburgh Sleep Quality Index (PSQI). Additionally, an open-ended section was included to determine the impact of COVID-19-related changes on sleep and work. The questionnaire responses were analyzed with descriptive and inferential statistics and the open-ended questions were analyzed with thematic analyses. A total of 84 respondents completed the questionnaire. On average, sleep quality was poor (global score of 7.09 ± 3.8), the reported sleep duration was short (6.41 ± 1.06 hrs) and the group was classified as overweight according to median BMI (26.67 [23.8-2 29.45] kg/m2). Over a third (35.71%) of academic staff reported not meeting physical activity guidelines and reported using screens one hour prior to bed every night during the week (76.19%) and the weekend (67.88%). Staff also worked long total weekly work hours (54.25 ± 11). Female academics had a poorer sleep quality (p = 0.035), spent a longer time in bed (p = 0.04), experienced more bad dreams (p = <0.01), had their last serving of alcohol earlier (p = 0.04) and worked less weekday (p = 0.04) and less total weekly (p = 0.02) hours compared to male academics. Professorship-level academics were significantly older than junior- and senior-level academics (p = <0.01) while senior-level academics had a poorer PSQI compared to professorship-level academics (p = 0.03). The thematic analysis showed that home environment, neighbourhood noise, work and mental health were the main emerging factors that disturbed sleep. The thematic analysis showed that, in relation to the impact of COVID19, sleep schedules changed and sleep duration and sleep quality improved or got worse. Respondents reported their work hours increasing, work schedules becoming less routine while working from home, dealing with the challenges of working online and experiencing worry, stress and anxiety due to the pandemic. The study highlights that, in the context of lockdown and having to work and teach online from home, academics reported poor quality sleep and short sleep duration. Further, on average, the sample reported working extensive hours and unhealthy lifestyle behaviours. The sleep health, nature of work and overall lifestyles of academic staff deserves more research attention, given the importance of their work and the impact that inadequate sleep could have on academics’ health and work performance. Sleep quality was worse for females and mid-career academics, suggesting that their sleep quality may be at greater risk than other sub-groups. However, the reasons for these differences need to be explored in future studies. The findings contribute to the narrative that academe involves numerous demands and supports previous research that has suggested that academics’ sleep is insufficient. Furthermore, COVID-19 had an impact on staff’s sleep, with staff reporting changes in their sleep quality and duration. The pandemic impacted work of academics by presenting novel demands related to online teaching, intensifying demands overall and disrupting work routines. However, future research is needed to understand academics’ sleep behaviours, work and lifestyles, especially in South Africa. , Thesis (MSc) -- Faculty of Science, Human Kinetics and Ergonomics, 2022
- Full Text:
- Date Issued: 2022-04-06
- Authors: Le Grange, Sarah-Ann
- Date: 2022-04-06
- Subjects: Sleep-wake cycle South Africa Eastern Cape , Sleep Physiological aspects , Lifestyles Health aspects South Africa Eastern Cape , COVID-19 Pandemic, 2020- Influence , Work environment Psychological aspects , Work environment Physiological aspects , College teachers Workload South Africa Eastern Cape , Pittsburgh Sleep Quality Index (PSQI)
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/291099 , vital:56818
- Description: Working in academe is characterized by high work demands, long and late working hours and balancing multiple roles. This often leaves academic staff (interchangeably referred to as ‘academics’ and ‘staff’) with limited time to prioritize adequate rest and sleep. While sufficient sleep is important for general well-being and work performance, it may be important for academics given the cognitive and interactive nature of their work. However, limited research has characterized sleep behaviours and sleep quality in academic staff globally and specifically in South Africa (SA). Further, research shows that academics from different academic ranks and genders differ in their work experiences but less is known about whether these factors affect their sleep and lifestyle factors. Over and above the demands of academic work, the current study was conducted during COVID-19, which saw unprecedented change in workloads for academic staff due to online teaching and learning. Additionally, the pandemic has been associated with poorer sleep quality and lifestyle behaviours in the general population, but very few studies have explored this in the context of academics. Thus, this study aimed to characterize the sleep quality, work and lifestyle factors among academics from a university in the Eastern Cape province of SA and determine the effects of gender and academic rank on these measures. Additionally, the study aimed to determine the impact of COVID-19 on sleep and work-related factors of this group. This study adopted a cross-sectional design and made use of an online questionnaire that was distributed to all academics employed at the institution via email. The data collection occurred over an 8-week testing period between August and September of 2020. The questionnaire explored sociodemographic, work and lifestyle characteristics, while the characteristics of sleep and sleep quality were explored with the Pittsburgh Sleep Quality Index (PSQI). Additionally, an open-ended section was included to determine the impact of COVID-19-related changes on sleep and work. The questionnaire responses were analyzed with descriptive and inferential statistics and the open-ended questions were analyzed with thematic analyses. A total of 84 respondents completed the questionnaire. On average, sleep quality was poor (global score of 7.09 ± 3.8), the reported sleep duration was short (6.41 ± 1.06 hrs) and the group was classified as overweight according to median BMI (26.67 [23.8-2 29.45] kg/m2). Over a third (35.71%) of academic staff reported not meeting physical activity guidelines and reported using screens one hour prior to bed every night during the week (76.19%) and the weekend (67.88%). Staff also worked long total weekly work hours (54.25 ± 11). Female academics had a poorer sleep quality (p = 0.035), spent a longer time in bed (p = 0.04), experienced more bad dreams (p = <0.01), had their last serving of alcohol earlier (p = 0.04) and worked less weekday (p = 0.04) and less total weekly (p = 0.02) hours compared to male academics. Professorship-level academics were significantly older than junior- and senior-level academics (p = <0.01) while senior-level academics had a poorer PSQI compared to professorship-level academics (p = 0.03). The thematic analysis showed that home environment, neighbourhood noise, work and mental health were the main emerging factors that disturbed sleep. The thematic analysis showed that, in relation to the impact of COVID19, sleep schedules changed and sleep duration and sleep quality improved or got worse. Respondents reported their work hours increasing, work schedules becoming less routine while working from home, dealing with the challenges of working online and experiencing worry, stress and anxiety due to the pandemic. The study highlights that, in the context of lockdown and having to work and teach online from home, academics reported poor quality sleep and short sleep duration. Further, on average, the sample reported working extensive hours and unhealthy lifestyle behaviours. The sleep health, nature of work and overall lifestyles of academic staff deserves more research attention, given the importance of their work and the impact that inadequate sleep could have on academics’ health and work performance. Sleep quality was worse for females and mid-career academics, suggesting that their sleep quality may be at greater risk than other sub-groups. However, the reasons for these differences need to be explored in future studies. The findings contribute to the narrative that academe involves numerous demands and supports previous research that has suggested that academics’ sleep is insufficient. Furthermore, COVID-19 had an impact on staff’s sleep, with staff reporting changes in their sleep quality and duration. The pandemic impacted work of academics by presenting novel demands related to online teaching, intensifying demands overall and disrupting work routines. However, future research is needed to understand academics’ sleep behaviours, work and lifestyles, especially in South Africa. , Thesis (MSc) -- Faculty of Science, Human Kinetics and Ergonomics, 2022
- Full Text:
- Date Issued: 2022-04-06
The regulation of privacy on cloud computing services in terms of the Protection of Personal Information Act 4 of 2013
- Authors: Malahleka, Mthuthukisi
- Date: 2022-04-06
- Subjects: South Africa. Protection of Personal Information Act, 2013 , Cloud computing Law and legislation South Africa , Data protection Law and legislation South Africa , Personal information management South Africa , Data privacy South Africa , Computer security Law and legislation South Africa , General Data Protection Regulation (GDPR)
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/290731 , vital:56779
- Description: There is a relatively new development in Information Technology (IT) space known as cloud computing, software and service delivered remotely through the Internet without installing software on a computer. Cloud computing has quickly gathered steam as one of the most prominent topics in IT, and indeed within the business sector as a whole. Cloud computing is one such development associated with opportunities and benefits, especially in the commercial sector. Due to the development of IT and many businesses adopting e-commerce business-related strategies, cloud computing has revolutionised how personal information is processed. The advent of cloud computing as a mechanism to process personal information has brought many legal challenges for protecting the right to privacy enshrined under section 14 of the South African Constitution, which is a vulnerable part of one’s personality right. The right to privacy has long been protected even before adopting the Constitution under the common law of delict (actio iniuriarumn). As the adoption rate of cloud computing services by businesses continues to increase, the legal considerations and risks become more prevalent. The lawmakers struggle to keep pace with the rapidly changing technological advancements, at least for now. Both the common law and the Constitution could not address all the legal aspects of data protection and the adoption of cloud computing services hence the promulgation of the Protection of Personal Information Act 4 of 2013 (POPI Act). The POPI Act’s main objective is to protect the personal information of both natural and juristic persons. Personal information about an individual forms part of privacy. Unlawful processing of such personal information is a violation of the right to privacy of an individual. It is now widely recognised that the unregulated processing of personal information significantly impacts fundamental human rights like privacy, personality, and autonomy. A close analysis of cloud computing regulation is necessary, as legal protection mechanisms must safeguard the processing of personal information and establish extraterritorial jurisdiction to regulate the use of cloud computing within national legislation as cloud computing provides a transnational characteristic on the cross-border flow of personal information. In this thesis, a question is asked on whether the current data protection laws in South Africa on protecting the right to privacy in the cloud computing services context are adequate. The analysis will determine whether the overlaps between these pieces of data protection laws are competent to deal with the ever-increasing threats on the right to privacy and if they meet the international data protection standards set by the European Union’s General Data Protection Regulation (GDPR). The research seeks to analyse and reveal the shortcomings under the Constitution and the common law that led to adopting the POPI Act by studying the regulation of cloud computing services. This analysis will determine the shortcomings of the POPI Act as well in the context of cloud computing. The research will then follow a comparative analysis of the POPI Act and the GDPR to determine the application of the GDPR on international data breaches and compare its provisions with the POPI Act in the context of cloud computing. Finally, the research will address the question as to whether a multi-faceted approach, which includes a Model Law on cloud computing, would be an appropriate starting point setting out requirements for the use of this technology can be sufficient in protecting data subjects. And as cloud computing risks are not only a national but also a global problem, South Africa needs to look at the option of entering into mutual agreements with other countries and organisations to regulate cloud computing at an international level. , Thesis (LLM) -- Faculty of Law, Law, 2022
- Full Text:
- Date Issued: 2022-04-06
- Authors: Malahleka, Mthuthukisi
- Date: 2022-04-06
- Subjects: South Africa. Protection of Personal Information Act, 2013 , Cloud computing Law and legislation South Africa , Data protection Law and legislation South Africa , Personal information management South Africa , Data privacy South Africa , Computer security Law and legislation South Africa , General Data Protection Regulation (GDPR)
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/290731 , vital:56779
- Description: There is a relatively new development in Information Technology (IT) space known as cloud computing, software and service delivered remotely through the Internet without installing software on a computer. Cloud computing has quickly gathered steam as one of the most prominent topics in IT, and indeed within the business sector as a whole. Cloud computing is one such development associated with opportunities and benefits, especially in the commercial sector. Due to the development of IT and many businesses adopting e-commerce business-related strategies, cloud computing has revolutionised how personal information is processed. The advent of cloud computing as a mechanism to process personal information has brought many legal challenges for protecting the right to privacy enshrined under section 14 of the South African Constitution, which is a vulnerable part of one’s personality right. The right to privacy has long been protected even before adopting the Constitution under the common law of delict (actio iniuriarumn). As the adoption rate of cloud computing services by businesses continues to increase, the legal considerations and risks become more prevalent. The lawmakers struggle to keep pace with the rapidly changing technological advancements, at least for now. Both the common law and the Constitution could not address all the legal aspects of data protection and the adoption of cloud computing services hence the promulgation of the Protection of Personal Information Act 4 of 2013 (POPI Act). The POPI Act’s main objective is to protect the personal information of both natural and juristic persons. Personal information about an individual forms part of privacy. Unlawful processing of such personal information is a violation of the right to privacy of an individual. It is now widely recognised that the unregulated processing of personal information significantly impacts fundamental human rights like privacy, personality, and autonomy. A close analysis of cloud computing regulation is necessary, as legal protection mechanisms must safeguard the processing of personal information and establish extraterritorial jurisdiction to regulate the use of cloud computing within national legislation as cloud computing provides a transnational characteristic on the cross-border flow of personal information. In this thesis, a question is asked on whether the current data protection laws in South Africa on protecting the right to privacy in the cloud computing services context are adequate. The analysis will determine whether the overlaps between these pieces of data protection laws are competent to deal with the ever-increasing threats on the right to privacy and if they meet the international data protection standards set by the European Union’s General Data Protection Regulation (GDPR). The research seeks to analyse and reveal the shortcomings under the Constitution and the common law that led to adopting the POPI Act by studying the regulation of cloud computing services. This analysis will determine the shortcomings of the POPI Act as well in the context of cloud computing. The research will then follow a comparative analysis of the POPI Act and the GDPR to determine the application of the GDPR on international data breaches and compare its provisions with the POPI Act in the context of cloud computing. Finally, the research will address the question as to whether a multi-faceted approach, which includes a Model Law on cloud computing, would be an appropriate starting point setting out requirements for the use of this technology can be sufficient in protecting data subjects. And as cloud computing risks are not only a national but also a global problem, South Africa needs to look at the option of entering into mutual agreements with other countries and organisations to regulate cloud computing at an international level. , Thesis (LLM) -- Faculty of Law, Law, 2022
- Full Text:
- Date Issued: 2022-04-06
The impact of urban gardening on household food security: evidence from Makhanda East, Eastern Cape Province, South Africa
- Bruwer, Guillaume Marcel Xavier
- Authors: Bruwer, Guillaume Marcel Xavier
- Date: 2022-04-06
- Subjects: Food security South Africa Makhanda , Urban agriculture South Africa Makhanda , Urban gardening South Africa Makhanda , Sustainable development South Africa Makhanda , South Africa Economic conditions , Subsistence farming South Africa Makhanda , Economic impact analysis South Africa Makhanda , Propensity Score Matching (PSM)
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/263575 , vital:53640
- Description: Urban gardening in townships is a common coping strategy employed by poor inhabitants to improve food security, earn income through sales, and generate cost-savings through home consumption of fresh produce. Food security is a cornerstone of human development and welfare, and the achievement thereof remains a global challenge. The majority of academic research and policy documentation traditionally positions food insecurity as a rural phenomenon. However, recent trends point to an increase in food insecurity in urban areas, particularly in low-income areas such as townships. In South Africa, rapid urbanization has led to burgeoning townships and rapidly expanding low-income informal settlements characterised by poverty, unemployment, and food insecurity. Research concerned with the role that urban agricultural production plays in contributing to the food security of poor households is scarce and not well understood. This research, therefore, aimed to contribute to the limited research which specifically examines urban food security, and the role urban agriculture play in the achievement of household food security. The study employed collective action theory and utility theory to firstly provides an in-depth examination of the determinants of participation in urban gardening using Probit regression modeling. The second research objective was to perform an impact evaluation of participation in urban gardening on selected household food security indicators including Household Dietary Diversity Scores (HDDS), the Household Hunger Scale (HHS) and the Coping Strategy Index (CSI) using Propensity Score Matching (PSM). Purposive and snowball sampling methods were employed to obtain a sample of 60 urban gardeners and a control group of 55 non-gardening households from Extension 6, 7 and 10 townships as well as Joza Location in Makhanda East, Eastern Cape Province. Households were surveyed using a structured household food security questionnaire. A focus group discussion was held with the Linomtha Community Garden members and key informant interviews were undertaken with important stakeholders such as the local extension officers. Descriptive analysis revealed that urban gardening households (UGs) had older household heads who were less educated, and that land and water availability were the dominant constraints to increases in agricultural production. Results from the probit and average marginal effects models showed that the likelihood of participation significantly increased when household unemployment and dependency increased and that households who were engaged in off-farm economic activity were more likely to participate in urban gardening. The impact evaluation was performed using PSM and Average Treatment Effect on the Treated (ATT). Analysis illustrated that participation in urban gardening does significantly reduce both the full CSI and Reduced CSI. Thus, participation in urban gardening improves the food security of participating households by significantly reducing the frequency of participating households (UGs) applying undesirable coping strategies such as sending children elsewhere other than the household, borrowing food from other households and reducing the number of meals eaten in a day due to food shortages. This study posits that urban gardening alone will not eradicate the rampant food insecurity and poverty which pervades in South Africa’s townships. However, urban gardening participation does contribute to the construction of a sustainable, urban livelihood by reducing the number and severity of the undesirable coping strategies that food insecure households employ by providing some nutritious produce as well improved social capital through gardening networks and supporting institutions. It is recommended that policy makers, at a national and municipal level, need to create a clearer directive for the integration of urban food production into the urban food marketplace thus increasing access to income generating channels for small-scale home, and community gardeners. Co-operation between private and public institutions for food security and urban gardeners needs to be fostered and awareness of opportunities to participate in urban gardens needs to be improved. Central to the developmental challenges that rapid increases in urbanization and food insecurity in poor urban areas, is the need for national and local governments to improve access to economic opportunities in township areas - both in urban agriculture and in other, skills intensive sectors. , Thesis (MEcon) -- Faculty of Commerce, Economics and Economic History, 2022
- Full Text:
- Date Issued: 2022-04-06
- Authors: Bruwer, Guillaume Marcel Xavier
- Date: 2022-04-06
- Subjects: Food security South Africa Makhanda , Urban agriculture South Africa Makhanda , Urban gardening South Africa Makhanda , Sustainable development South Africa Makhanda , South Africa Economic conditions , Subsistence farming South Africa Makhanda , Economic impact analysis South Africa Makhanda , Propensity Score Matching (PSM)
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/263575 , vital:53640
- Description: Urban gardening in townships is a common coping strategy employed by poor inhabitants to improve food security, earn income through sales, and generate cost-savings through home consumption of fresh produce. Food security is a cornerstone of human development and welfare, and the achievement thereof remains a global challenge. The majority of academic research and policy documentation traditionally positions food insecurity as a rural phenomenon. However, recent trends point to an increase in food insecurity in urban areas, particularly in low-income areas such as townships. In South Africa, rapid urbanization has led to burgeoning townships and rapidly expanding low-income informal settlements characterised by poverty, unemployment, and food insecurity. Research concerned with the role that urban agricultural production plays in contributing to the food security of poor households is scarce and not well understood. This research, therefore, aimed to contribute to the limited research which specifically examines urban food security, and the role urban agriculture play in the achievement of household food security. The study employed collective action theory and utility theory to firstly provides an in-depth examination of the determinants of participation in urban gardening using Probit regression modeling. The second research objective was to perform an impact evaluation of participation in urban gardening on selected household food security indicators including Household Dietary Diversity Scores (HDDS), the Household Hunger Scale (HHS) and the Coping Strategy Index (CSI) using Propensity Score Matching (PSM). Purposive and snowball sampling methods were employed to obtain a sample of 60 urban gardeners and a control group of 55 non-gardening households from Extension 6, 7 and 10 townships as well as Joza Location in Makhanda East, Eastern Cape Province. Households were surveyed using a structured household food security questionnaire. A focus group discussion was held with the Linomtha Community Garden members and key informant interviews were undertaken with important stakeholders such as the local extension officers. Descriptive analysis revealed that urban gardening households (UGs) had older household heads who were less educated, and that land and water availability were the dominant constraints to increases in agricultural production. Results from the probit and average marginal effects models showed that the likelihood of participation significantly increased when household unemployment and dependency increased and that households who were engaged in off-farm economic activity were more likely to participate in urban gardening. The impact evaluation was performed using PSM and Average Treatment Effect on the Treated (ATT). Analysis illustrated that participation in urban gardening does significantly reduce both the full CSI and Reduced CSI. Thus, participation in urban gardening improves the food security of participating households by significantly reducing the frequency of participating households (UGs) applying undesirable coping strategies such as sending children elsewhere other than the household, borrowing food from other households and reducing the number of meals eaten in a day due to food shortages. This study posits that urban gardening alone will not eradicate the rampant food insecurity and poverty which pervades in South Africa’s townships. However, urban gardening participation does contribute to the construction of a sustainable, urban livelihood by reducing the number and severity of the undesirable coping strategies that food insecure households employ by providing some nutritious produce as well improved social capital through gardening networks and supporting institutions. It is recommended that policy makers, at a national and municipal level, need to create a clearer directive for the integration of urban food production into the urban food marketplace thus increasing access to income generating channels for small-scale home, and community gardeners. Co-operation between private and public institutions for food security and urban gardeners needs to be fostered and awareness of opportunities to participate in urban gardens needs to be improved. Central to the developmental challenges that rapid increases in urbanization and food insecurity in poor urban areas, is the need for national and local governments to improve access to economic opportunities in township areas - both in urban agriculture and in other, skills intensive sectors. , Thesis (MEcon) -- Faculty of Commerce, Economics and Economic History, 2022
- Full Text:
- Date Issued: 2022-04-06
Transfer pricing: an analysis of legislation in the southern African Customs Union
- Authors: Patel, Nabil Ahmed
- Date: 2022-04-06
- Subjects: Transfer pricing
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/241482 , vital:50943
- Description: Transfer pricing is defined as the setting of the price for goods sold and services rendered between related entities. For example, if a subsidiary company sells goods or renders services to its holding company or a sister company, the price charged is referred to as the transfer price. Transfer pricing can be used to manipulate profits and facilitate tax evasion. Therefore, it is important that countries enact transfer pricing legislation to prevent this. The United Nations (UN) and Organisation for Economic Co-operation and Development (OECD) guideline documents form the basis for most global legislation and conventions dealing with transfer pricing. The over-arching goal of this research was to investigate whether transfer pricing legislation in the Southern African Customs Union (SACU) aligns between SACU countries and with the OECD Guidelines and the UN Manual. The research applied a legal interpretive doctrinal research methodology and a qualitative research method. The data comprised primary legislation in the SACU countries, transfer pricing guidelines issued by revenue authorities in the SACU, OECD Guidelines, the UN Manual and journal articles. It was found in this study that certain aspects of transfer pricing legislation in the SACU are not fully aligned to each other and to the OECD Guidelines and the UN Manual. This study proposed recommendations to improve transfer pricing legislation in the SACU. These improvements include the introduction of transfer pricing legislation in Eswatini and Lesotho, and updating transfer pricing legislation in Namibia and South Africa in terms of the latest versions of the OECD Guidelines and the UN Manual. , Thesis (MCom) -- Faculty of Commerce, Accounting, 2022
- Full Text:
- Date Issued: 2022-04-06
- Authors: Patel, Nabil Ahmed
- Date: 2022-04-06
- Subjects: Transfer pricing
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/241482 , vital:50943
- Description: Transfer pricing is defined as the setting of the price for goods sold and services rendered between related entities. For example, if a subsidiary company sells goods or renders services to its holding company or a sister company, the price charged is referred to as the transfer price. Transfer pricing can be used to manipulate profits and facilitate tax evasion. Therefore, it is important that countries enact transfer pricing legislation to prevent this. The United Nations (UN) and Organisation for Economic Co-operation and Development (OECD) guideline documents form the basis for most global legislation and conventions dealing with transfer pricing. The over-arching goal of this research was to investigate whether transfer pricing legislation in the Southern African Customs Union (SACU) aligns between SACU countries and with the OECD Guidelines and the UN Manual. The research applied a legal interpretive doctrinal research methodology and a qualitative research method. The data comprised primary legislation in the SACU countries, transfer pricing guidelines issued by revenue authorities in the SACU, OECD Guidelines, the UN Manual and journal articles. It was found in this study that certain aspects of transfer pricing legislation in the SACU are not fully aligned to each other and to the OECD Guidelines and the UN Manual. This study proposed recommendations to improve transfer pricing legislation in the SACU. These improvements include the introduction of transfer pricing legislation in Eswatini and Lesotho, and updating transfer pricing legislation in Namibia and South Africa in terms of the latest versions of the OECD Guidelines and the UN Manual. , Thesis (MCom) -- Faculty of Commerce, Accounting, 2022
- Full Text:
- Date Issued: 2022-04-06
Institutional innovations for improved water security in smallholder irrigation schemes in KwaZulu-Natal and Eastern Cape Provinces, South Africa
- Authors: Phakathi, Sandile
- Date: 2022-04-06
- Subjects: Water security South Africa , Rural development projects South Africa , Institutional cooperation South Africa , Irrigation farming South Africa , Food security South Africa , Agricultural innovations South Africa , Irrigation Technological innovations South Africa , Smallholder irrigation schemes
- Language: English
- Type: Doctoral thesis , text
- Identifier: http://hdl.handle.net/10962/232341 , vital:49983 , DOI 10.21504/10962/232341
- Description: Smallholder irrigation schemes are regarded as a key strategy to eliminate poverty and increase food security in rural areas in South Africa. While the South African government has invested heavily in rural development schemes, most irrigation schemes face a myriad of challenges, including deficient infrastructure, weak institutional arrangements and water insecurity. Weak institutions have been identified as a major bottleneck in the performance of smallholder irrigation schemes in developing countries, including South Africa. Two main reasons have been identified for this challenge. Firstly, the agency of the irrigators was ignored during the design of the schemes. Treating farmers as passive rather than active agents resulted in institutional arrangements that were not context-specific, as well as weak farmer commitment to the ownership and management of the schemes, leading to system breakdown. Despite being noble in intention or design, institutions designed by outsiders often fail due to a lack of legitimacy. Secondly, institutions have failed to evolve to cope with dynamic challenges and opportunities in the sector. Stability over a reasonable period is required for institutions to effectively perform their crucial role of establishing reasonable expectations in dealings among people. Institutional innovations are required to keep up with the changing nature of development. In particular, farmer-led institutional innovations have been touted as key to improving the management of water resources in irrigation schemes. Farmer-led institutional innovation refers to a process, in which farmers themselves initiate, establish, and improve institutions based on their context-specific challenges or opportunities. Farmers’ groups are regarded as an important institutional arrangement to reduce transaction costs, improve social networks, and increase livelihood outcomes. However, little is known about the internal dynamics of these farmer groups, how they operate, and whether or not they are inclusive and innovative, as well as what makes certain groups more successful than others. Furthermore, there is a paucity of research on whether these farmer groups embrace institutional innovations to improve water security and strengthen their design principles that are crucial for collective action. It is against this background that this study aimed to examine the internal group dynamics within the farmer groups; determine whether smallholder farmers are capable of implementing institutional innovations that are novel, useful and legitimate; determine the nature of these innovations (incremental or radical) and their role in improving water security. The main theories that underpinned the study were induced institutional innovation theory, collective action theory, random utility theory and Ostrom’s eight design principles. Multistage sampling was used to collect data from 28 farmer groups and 401 irrigators in smallholder irrigation schemes in KwaZulu-Natal (Tugela Ferry and Mooi River) and the Eastern Cape (Qamata and Zanyokwe). Data were gathered by means of focus group discussions, key informant interviews and household surveys. Several empirical tools were employed to analyse the data (descriptive statistics, thematic analysis, logit model, propensity score matching, PCA and OLS). The study found that group membership was associated with higher levels of water access, adoption of inorganic fertiliser, incomes and assets. Group members had an additional four days’ access to water in a month and applied at least 130 kg/ha more inorganic fertiliser than non-group members. Group members also had a higher household income per capita and more assets than non-group members. However, the results revealed a heterogeneous effect among group members, with the benefits varying according to members’ socio-economic characteristics as well as internal group dynamics. The results suggest that organising farmers into groups should be promoted to improve farmers’ access to productive assets such as water, technology adoption and welfare outcomes. However, the study findings also indicate that smaller groups should be promoted, programmes targeted at empowering women should be prioritised, and that it is imperative to invest in improving farmers’ human capital through various training initiatives. The results indicated that farmers could develop and implement institutional innovations that are novel, useful and legitimate. Of the 28 groups, 21 (75%) had implemented institutional innovations in the past three years. Examples of innovations include, among others, the introduction of a secret voting system to improve marginalised people’s participation in decision-making processes, designing daily rotation rosters to reduce conflict, using an attendance register for participation in group activities, and rewarding members according to their participation levels. Most of these innovations were designed to improve the graduated sanction mechanism (22.2%), enhance the penalty system for non-compliance; improve collective action arrangements (27.8%); monitor attendance of group meetings (18.5%); democratise decision making; and ensure equitable water distribution. However, they mainly focused on addressing challenges rather than exploiting opportunities and were largely incremental (94%), involving an adjustment or reinterpretation of rules and regulations. Furthermore, the innovative groups were small in size and were dominated by male farmers. Based on these results, it is recommended that the government should build on the irrigators’ agency to improve the effectiveness and legitimacy of institutional arrangements in irrigation schemes. The findings also suggest that small groups should be actively promoted, while tailored training should be offered based on the groups’ specific needs to improve institutional innovations in the smallholder irrigation sector in South Africa. A positive association was established between belonging to an innovative group and water security, highlighting the importance of institutional innovations in water security. The propensity score matching indicated that water secure irrigators produced an additional 569-622 kg of maize and earned additional income of R2 037.81. The study’s findings suggest that organising farmers into groups is a promising strategy to improve farmers livelihoods and water security. The government and private donors should thus continue to promote the formation and organisation of farmers into groups. The innovative agency of the irrigators should be acknowledged and harnessed to strengthen institutional innovations. The focus should be on strengthening the institutions designed by farmers themselves, as these are locally contextualised and socially embedded, and hence legitimate. It is recommended that small groups should be actively promoted, while tailored training should be offered based on groups’ specific needs to improve institutional innovations in the smallholder irrigation sector in South Africa. , Thesis (PhD) -- Faculty of Commerce, Economics and Economic History, 2022
- Full Text:
- Date Issued: 2022-04-06
- Authors: Phakathi, Sandile
- Date: 2022-04-06
- Subjects: Water security South Africa , Rural development projects South Africa , Institutional cooperation South Africa , Irrigation farming South Africa , Food security South Africa , Agricultural innovations South Africa , Irrigation Technological innovations South Africa , Smallholder irrigation schemes
- Language: English
- Type: Doctoral thesis , text
- Identifier: http://hdl.handle.net/10962/232341 , vital:49983 , DOI 10.21504/10962/232341
- Description: Smallholder irrigation schemes are regarded as a key strategy to eliminate poverty and increase food security in rural areas in South Africa. While the South African government has invested heavily in rural development schemes, most irrigation schemes face a myriad of challenges, including deficient infrastructure, weak institutional arrangements and water insecurity. Weak institutions have been identified as a major bottleneck in the performance of smallholder irrigation schemes in developing countries, including South Africa. Two main reasons have been identified for this challenge. Firstly, the agency of the irrigators was ignored during the design of the schemes. Treating farmers as passive rather than active agents resulted in institutional arrangements that were not context-specific, as well as weak farmer commitment to the ownership and management of the schemes, leading to system breakdown. Despite being noble in intention or design, institutions designed by outsiders often fail due to a lack of legitimacy. Secondly, institutions have failed to evolve to cope with dynamic challenges and opportunities in the sector. Stability over a reasonable period is required for institutions to effectively perform their crucial role of establishing reasonable expectations in dealings among people. Institutional innovations are required to keep up with the changing nature of development. In particular, farmer-led institutional innovations have been touted as key to improving the management of water resources in irrigation schemes. Farmer-led institutional innovation refers to a process, in which farmers themselves initiate, establish, and improve institutions based on their context-specific challenges or opportunities. Farmers’ groups are regarded as an important institutional arrangement to reduce transaction costs, improve social networks, and increase livelihood outcomes. However, little is known about the internal dynamics of these farmer groups, how they operate, and whether or not they are inclusive and innovative, as well as what makes certain groups more successful than others. Furthermore, there is a paucity of research on whether these farmer groups embrace institutional innovations to improve water security and strengthen their design principles that are crucial for collective action. It is against this background that this study aimed to examine the internal group dynamics within the farmer groups; determine whether smallholder farmers are capable of implementing institutional innovations that are novel, useful and legitimate; determine the nature of these innovations (incremental or radical) and their role in improving water security. The main theories that underpinned the study were induced institutional innovation theory, collective action theory, random utility theory and Ostrom’s eight design principles. Multistage sampling was used to collect data from 28 farmer groups and 401 irrigators in smallholder irrigation schemes in KwaZulu-Natal (Tugela Ferry and Mooi River) and the Eastern Cape (Qamata and Zanyokwe). Data were gathered by means of focus group discussions, key informant interviews and household surveys. Several empirical tools were employed to analyse the data (descriptive statistics, thematic analysis, logit model, propensity score matching, PCA and OLS). The study found that group membership was associated with higher levels of water access, adoption of inorganic fertiliser, incomes and assets. Group members had an additional four days’ access to water in a month and applied at least 130 kg/ha more inorganic fertiliser than non-group members. Group members also had a higher household income per capita and more assets than non-group members. However, the results revealed a heterogeneous effect among group members, with the benefits varying according to members’ socio-economic characteristics as well as internal group dynamics. The results suggest that organising farmers into groups should be promoted to improve farmers’ access to productive assets such as water, technology adoption and welfare outcomes. However, the study findings also indicate that smaller groups should be promoted, programmes targeted at empowering women should be prioritised, and that it is imperative to invest in improving farmers’ human capital through various training initiatives. The results indicated that farmers could develop and implement institutional innovations that are novel, useful and legitimate. Of the 28 groups, 21 (75%) had implemented institutional innovations in the past three years. Examples of innovations include, among others, the introduction of a secret voting system to improve marginalised people’s participation in decision-making processes, designing daily rotation rosters to reduce conflict, using an attendance register for participation in group activities, and rewarding members according to their participation levels. Most of these innovations were designed to improve the graduated sanction mechanism (22.2%), enhance the penalty system for non-compliance; improve collective action arrangements (27.8%); monitor attendance of group meetings (18.5%); democratise decision making; and ensure equitable water distribution. However, they mainly focused on addressing challenges rather than exploiting opportunities and were largely incremental (94%), involving an adjustment or reinterpretation of rules and regulations. Furthermore, the innovative groups were small in size and were dominated by male farmers. Based on these results, it is recommended that the government should build on the irrigators’ agency to improve the effectiveness and legitimacy of institutional arrangements in irrigation schemes. The findings also suggest that small groups should be actively promoted, while tailored training should be offered based on the groups’ specific needs to improve institutional innovations in the smallholder irrigation sector in South Africa. A positive association was established between belonging to an innovative group and water security, highlighting the importance of institutional innovations in water security. The propensity score matching indicated that water secure irrigators produced an additional 569-622 kg of maize and earned additional income of R2 037.81. The study’s findings suggest that organising farmers into groups is a promising strategy to improve farmers livelihoods and water security. The government and private donors should thus continue to promote the formation and organisation of farmers into groups. The innovative agency of the irrigators should be acknowledged and harnessed to strengthen institutional innovations. The focus should be on strengthening the institutions designed by farmers themselves, as these are locally contextualised and socially embedded, and hence legitimate. It is recommended that small groups should be actively promoted, while tailored training should be offered based on groups’ specific needs to improve institutional innovations in the smallholder irrigation sector in South Africa. , Thesis (PhD) -- Faculty of Commerce, Economics and Economic History, 2022
- Full Text:
- Date Issued: 2022-04-06
The assessment of degradation state in Ecological Infrastructure and prioritisation for rehabilitation and drought mitigation in the Tsitsa River Catchment
- Authors: Mahlaba, Bawinile
- Date: 2022-04-06
- Subjects: Environmental degradation South Africa Eastern Cape , Restoration ecology South Africa Eastern Cape , Climate change mitigation South Africa Eastern Cape , Droughts South Africa Eastern Cape , South African National Biodiversity Institute , Sustainable development South Africa Eastern Cape , Watersheds , Ecological Infrastructure (EI) , Tsitsa River Catchment
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/202138 , vital:46470
- Description: Ecosystem degradation is a serious concern globally, including in South Africa, because of the potential adverse impacts on food security, livelihoods, climate change, biodiversity, and ecosystem services. Ecosystem degradation can result in flow alteration in the landscape through changes in the hydrological regime. The study adopts the South African National Biodiversity Institute (SANBI) Framework of Investing in Ecological Infrastructure (EI) to prioritise the restoration of degraded ecosystems and maintain ecosystem structures and functions. This study aims to assess how EI (specifically wetlands, grassland, abandoned cultivated fields, and riparian zone) can facilitate drought mitigation: to assess land degradation status and identify priority EI areas that can be restored to improve the drought mitigation capacity. Two assessment methods were used in this study. Firstly, the Trends.Earth tool was used to assess degradation and land cover change from the year 2000-2015 in Tsitsa catchment, through assessment of Sustainable Development Goal degradation indicator (SDG15.3.1) at a resolution of 300 m. The degradation indicator uses information from three sub-indicators: Productivity, Landcover and Soil Organic Carbon to compute degraded areas. The degraded areas need to be restored and rehabilitated to maintain the flow of essential ecosystems services provided by EI. The second assessment used the Analytical Hierarchy Process (AHP), which integrates stakeholder inputs into a multi-criteria decision analysis (MCDA). The AHP is a useful decision support system that considers a range of quantitative and qualitative alternatives in making a final decision to solve complex problems. As part of the AHP analysis, participatory mapping using Participatory Geographic Information System was conducted to obtain stakeholder inputs for prioritising restoration of the key EI categories (wetlands, grassland, abandoned cultivated fields, and riparian zone) in the catchment. During the participatory mapping, communities prioritised the key EI based on three criteria: (1) ecosystem health, (2) water provisioning and (3) social benefits. The AHP method was used in ArcGIS to prioritise suitable key EI restoration areas with high potential to increase water recharge and storage, contribute to drought mitigation and ecosystem services for the catchment. The prioritisation of EI for community livelihoods in the AHP analysis included all three main criteria. In comparison, the prioritisation of suitable key EI restoration areas for flow regulations was based on two criteria: ecosystem health and water provisioning. The land degradation indicator showed that approximately 54% of the catchment is stable, 41% is degraded land, and 5% of the area has improved over the assessment period (15 years). The degradation status in the EI suggests that more than half (>50%) of each EI category is stable, but there are areas showing signs of degradation, including 43% of grasslands degraded and 39% of wetlands, cultivated lands, and riparian zones also degraded. Degradation is dominant in the upper (T35B and T3C) and lower (T35K, T35L and T35M) parts of the catchments. The three criteria used by the stakeholders in the prioritisation process of the key EI were assigned 12 spatial attributes (the catchment characteristics about the study area in relation to the criteria) to indicate relevant information needed for selecting suitable restoration areas to enhance flow regulation. The AHP analysis results identified approximately 63% (17,703 ha) of wetlands, 88% (235,829 ha) of grasslands, 78% (13,608 ha) of abandoned cultivated fields and 93% (3,791 ha) of the riparian zones as suitable areas for restoration to mitigate drought impact through flow regulation. Also, the suitability results showed 63% (17,703 ha) of wetlands, 58% (2,203 ha) of riparian zones, 68% (11,745 ha) of abandoned cultivated fields and 46% (122,285 ha) of grasslands as suitable restoration areas for improving ecosystem services for community livelihoods. The AHP analysis identified more than 39-43% (of the degraded EI indicated by the Trends.Earth analysis) areas that are suitable for restoration, because key EI plays a significant role in flow regulation and people’s livelihoods, especially when they are managed, maintained, and restored to good health conditions. Therefore, the prioritized EI areas should be either maintained, managed, rehabilitated or restored. The major distinct causes of land degradation are woody encroachment in grasslands, invasion of alien plants on abandoned cultivated fields and soil erosion in the catchment. The most suitable EI areas recommended for restoration are those natural resources near local communities, which provide essential ecosystem services to sustain their livelihood. Therefore, degraded EI in the T35 catchments should be restored and maintained to improve livelihood and mitigate drought impacts. The study pointed out how the key selected ecological infrastructure can help mitigate the impacts of droughts and improve human livelihood. The study contributes towards the important concept of investing in ecological infrastructure to improve the social, environmental, and economic benefits. , Thesis (MSc) -- Faculty of Science, Institute for Water Research, 2022
- Full Text:
- Date Issued: 2022-04-06
- Authors: Mahlaba, Bawinile
- Date: 2022-04-06
- Subjects: Environmental degradation South Africa Eastern Cape , Restoration ecology South Africa Eastern Cape , Climate change mitigation South Africa Eastern Cape , Droughts South Africa Eastern Cape , South African National Biodiversity Institute , Sustainable development South Africa Eastern Cape , Watersheds , Ecological Infrastructure (EI) , Tsitsa River Catchment
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/202138 , vital:46470
- Description: Ecosystem degradation is a serious concern globally, including in South Africa, because of the potential adverse impacts on food security, livelihoods, climate change, biodiversity, and ecosystem services. Ecosystem degradation can result in flow alteration in the landscape through changes in the hydrological regime. The study adopts the South African National Biodiversity Institute (SANBI) Framework of Investing in Ecological Infrastructure (EI) to prioritise the restoration of degraded ecosystems and maintain ecosystem structures and functions. This study aims to assess how EI (specifically wetlands, grassland, abandoned cultivated fields, and riparian zone) can facilitate drought mitigation: to assess land degradation status and identify priority EI areas that can be restored to improve the drought mitigation capacity. Two assessment methods were used in this study. Firstly, the Trends.Earth tool was used to assess degradation and land cover change from the year 2000-2015 in Tsitsa catchment, through assessment of Sustainable Development Goal degradation indicator (SDG15.3.1) at a resolution of 300 m. The degradation indicator uses information from three sub-indicators: Productivity, Landcover and Soil Organic Carbon to compute degraded areas. The degraded areas need to be restored and rehabilitated to maintain the flow of essential ecosystems services provided by EI. The second assessment used the Analytical Hierarchy Process (AHP), which integrates stakeholder inputs into a multi-criteria decision analysis (MCDA). The AHP is a useful decision support system that considers a range of quantitative and qualitative alternatives in making a final decision to solve complex problems. As part of the AHP analysis, participatory mapping using Participatory Geographic Information System was conducted to obtain stakeholder inputs for prioritising restoration of the key EI categories (wetlands, grassland, abandoned cultivated fields, and riparian zone) in the catchment. During the participatory mapping, communities prioritised the key EI based on three criteria: (1) ecosystem health, (2) water provisioning and (3) social benefits. The AHP method was used in ArcGIS to prioritise suitable key EI restoration areas with high potential to increase water recharge and storage, contribute to drought mitigation and ecosystem services for the catchment. The prioritisation of EI for community livelihoods in the AHP analysis included all three main criteria. In comparison, the prioritisation of suitable key EI restoration areas for flow regulations was based on two criteria: ecosystem health and water provisioning. The land degradation indicator showed that approximately 54% of the catchment is stable, 41% is degraded land, and 5% of the area has improved over the assessment period (15 years). The degradation status in the EI suggests that more than half (>50%) of each EI category is stable, but there are areas showing signs of degradation, including 43% of grasslands degraded and 39% of wetlands, cultivated lands, and riparian zones also degraded. Degradation is dominant in the upper (T35B and T3C) and lower (T35K, T35L and T35M) parts of the catchments. The three criteria used by the stakeholders in the prioritisation process of the key EI were assigned 12 spatial attributes (the catchment characteristics about the study area in relation to the criteria) to indicate relevant information needed for selecting suitable restoration areas to enhance flow regulation. The AHP analysis results identified approximately 63% (17,703 ha) of wetlands, 88% (235,829 ha) of grasslands, 78% (13,608 ha) of abandoned cultivated fields and 93% (3,791 ha) of the riparian zones as suitable areas for restoration to mitigate drought impact through flow regulation. Also, the suitability results showed 63% (17,703 ha) of wetlands, 58% (2,203 ha) of riparian zones, 68% (11,745 ha) of abandoned cultivated fields and 46% (122,285 ha) of grasslands as suitable restoration areas for improving ecosystem services for community livelihoods. The AHP analysis identified more than 39-43% (of the degraded EI indicated by the Trends.Earth analysis) areas that are suitable for restoration, because key EI plays a significant role in flow regulation and people’s livelihoods, especially when they are managed, maintained, and restored to good health conditions. Therefore, the prioritized EI areas should be either maintained, managed, rehabilitated or restored. The major distinct causes of land degradation are woody encroachment in grasslands, invasion of alien plants on abandoned cultivated fields and soil erosion in the catchment. The most suitable EI areas recommended for restoration are those natural resources near local communities, which provide essential ecosystem services to sustain their livelihood. Therefore, degraded EI in the T35 catchments should be restored and maintained to improve livelihood and mitigate drought impacts. The study pointed out how the key selected ecological infrastructure can help mitigate the impacts of droughts and improve human livelihood. The study contributes towards the important concept of investing in ecological infrastructure to improve the social, environmental, and economic benefits. , Thesis (MSc) -- Faculty of Science, Institute for Water Research, 2022
- Full Text:
- Date Issued: 2022-04-06
An investigation into the force-EMG relationship for static and dynamic exertions
- Koekemoer, Wesley Agosthinho
- Authors: Koekemoer, Wesley Agosthinho
- Date: 2022-04-06
- Subjects: Electromyography , Force and energy , Muscles Physiology , Biomechanics , Muscle contraction , Isometric exercise , Isotonic exercise , Static and dynamic exertions
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/291076 , vital:56816
- Description: The force-EMG relationship has multiple applications in varying fields of study and practice. One such application is the development of safety guidelines and regulations. Current guidelines are based on static muscle actions even though the majority of tasks encountered in industry are dynamic in nature. This may have negative implications for the health, safety, and productivity of workers as regulations based on static muscle actions may place higher force demands on manual labourers compared to what would be expected if regulations were based on dynamic muscle actions. Regulations based on dynamic muscle actions may be more effective in worker safety as the nature of the regulation matches that of the demand. Few studies have investigated the force-EMG relationship during dynamic muscle actions and the few that do exist have reported contradictory / mixed results. Therefore, the purpose of this study was to: 1) gain an understanding of EMG responses at different load levels, and 2) show how the relationship differs between static and dynamic muscle actions. A two-factorial repeated-measures experiment was developed for this study. Eighteen experimental conditions, utilizing six load levels (0%, 20%, 40%, 60%, 80%, and 100% of maximum voluntary force) for each of the three muscle actions (isometric, concentric and eccentric). Surface EMG responses were obtained under these conditions by repeatedly dorsiflexing and plantarflexing the foot, thus activating the soleus muscle. A maximum voluntary exertion on an isokinetic dynamometer determined the maximum force level, based on which the sub-maximal loads were calculated and added to a pulley system. 31 student participants were recruited for this experiment which was conducted over two sessions – one information and habituation session, and one experimental session. The EMG data recorded were processed and checked for normality and outliers. The data was then analysed via a General Linear Model analysis to determine the effect of exertion type and of load level on the muscle activity. Significant differences were identified at p<0.05 and followed by a Tukey post-hoc test. Correlation analyses were also conducted to determine the relationship between the force and EMG at all three exertion types. All dependent measures showed that as the load level increased so did the sEMG amplitude for all muscle actions. Muscle actions differed significantly between majority of six force levels. Correlations between the load levels and sEMG amplitude for each muscle action indicated a significant correlation with a moderate strength. The conclusion draws from this study that there is a positive correlation between force and sEMG amplitude, at all load levels, with a moderate strength. However, the muscle actions differed significantly from each other. , Thesis (MSc) -- Faculty of Science, Human Kinetics and Ergonomics, 2022
- Full Text:
- Date Issued: 2022-04-06
- Authors: Koekemoer, Wesley Agosthinho
- Date: 2022-04-06
- Subjects: Electromyography , Force and energy , Muscles Physiology , Biomechanics , Muscle contraction , Isometric exercise , Isotonic exercise , Static and dynamic exertions
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/291076 , vital:56816
- Description: The force-EMG relationship has multiple applications in varying fields of study and practice. One such application is the development of safety guidelines and regulations. Current guidelines are based on static muscle actions even though the majority of tasks encountered in industry are dynamic in nature. This may have negative implications for the health, safety, and productivity of workers as regulations based on static muscle actions may place higher force demands on manual labourers compared to what would be expected if regulations were based on dynamic muscle actions. Regulations based on dynamic muscle actions may be more effective in worker safety as the nature of the regulation matches that of the demand. Few studies have investigated the force-EMG relationship during dynamic muscle actions and the few that do exist have reported contradictory / mixed results. Therefore, the purpose of this study was to: 1) gain an understanding of EMG responses at different load levels, and 2) show how the relationship differs between static and dynamic muscle actions. A two-factorial repeated-measures experiment was developed for this study. Eighteen experimental conditions, utilizing six load levels (0%, 20%, 40%, 60%, 80%, and 100% of maximum voluntary force) for each of the three muscle actions (isometric, concentric and eccentric). Surface EMG responses were obtained under these conditions by repeatedly dorsiflexing and plantarflexing the foot, thus activating the soleus muscle. A maximum voluntary exertion on an isokinetic dynamometer determined the maximum force level, based on which the sub-maximal loads were calculated and added to a pulley system. 31 student participants were recruited for this experiment which was conducted over two sessions – one information and habituation session, and one experimental session. The EMG data recorded were processed and checked for normality and outliers. The data was then analysed via a General Linear Model analysis to determine the effect of exertion type and of load level on the muscle activity. Significant differences were identified at p<0.05 and followed by a Tukey post-hoc test. Correlation analyses were also conducted to determine the relationship between the force and EMG at all three exertion types. All dependent measures showed that as the load level increased so did the sEMG amplitude for all muscle actions. Muscle actions differed significantly between majority of six force levels. Correlations between the load levels and sEMG amplitude for each muscle action indicated a significant correlation with a moderate strength. The conclusion draws from this study that there is a positive correlation between force and sEMG amplitude, at all load levels, with a moderate strength. However, the muscle actions differed significantly from each other. , Thesis (MSc) -- Faculty of Science, Human Kinetics and Ergonomics, 2022
- Full Text:
- Date Issued: 2022-04-06
Stock market volatility during times of crisis: a comparative analysis of the conditional volatilities of JSE stock indices during the 2007/08 global financial crisis and COVID-19
- Authors: Wang, Zixiao
- Date: 2022-04-06
- Subjects: Stock exchanges , Johannesburg Stock Exchange , Global Financial Crisis, 2008-2009 , COVID-19 (Disease) Economic aspects , Economic forecasting , Stock exchanges and current events , GARCH model
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/284603 , vital:56078
- Description: This research analyses the comparative behaviour of stock market volatility during two crises. The goal of this research is to determine whether assumed cyclical and defensive sectors have either retained or revealed their expected properties during both the Global Financial Crisis (GFC) and COVID-19 by analysing sectoral volatility amid these two crises. Understanding how volatility changes amid crises helps to determine whether the volatility assumptions of diversified investment portfolios for both defensive and cyclical sectors still held given the different causes of each crisis. In turn, this knowledge can assist with risk management and portfolio allocation in stock market investments. The study can also contribute towards the enhancement of financial markets’ resistance against systemic risks through portfolio diversification, and aid government decision-making targeted at tackling the weaknesses of different economic sectors especially in times of overall economic weakness. This research makes use of the GARCH model to analyse a group of daily time series that consists of eleven sectoral indices and one benchmark index, all based on the South African stock markets. These observed series are categorised into two full sample periods, one designated to the Global Financial Crisis (January 2006 to May 2009) and the other for COVID-19 (January 2018 to May 2021). These are further divided into two sets of sub-sample periods, each made up of a pre-crisis and during-crisis. Furthermore, the dummy variables representing the occurrence of structural breaks are inserted into the full sample periods’ conditional variance equations. This is aimed at capturing the asymmetrical impact of the crises themselves on all observed series. Based on the movement of volatility persistency from pre-crisis to during-crisis for both crises, the results show that, firstly, Health Care and Consumer Goods are considered defensive Sectors. Secondly, Banks, Basic Materials, Chemicals, Telecommunications, and Financials are considered cyclical Sectors. Thirdly, Automobiles & Parts, Consumer Services, and Technology are considered indeterminable Sectors due to the inconsistent behaviour of these sectors’ volatility persistency throughout the sub-sample periods of both crises. Overall, according to the average volatility persistency, the observed series for COVID-19’s full sample period are generally less volatile than those of the GFC. However, the sub-sample periods suggest that the observed series for both pre-crisis and during-crisis periods of COVID-19 are more volatile than those same sub-samples of the Global Financial Crisis. Being able to analyse the characteristics of stock market sectors is crucial for risk management and optimal portfolio allocation of stock market investments. This can be achieved through portfolio diversification by investing in a variety of stocks, both cyclical and defensive, and adjusted over time based the needs of stock market investors. Diversified portfolios do not only serve the interests of individual investors, but can also enhance the financial markets’ overall resistance against systemic risks. , Thesis (MCom) -- Faculty of Commerce, Economics and Economic History, 2022
- Full Text:
- Date Issued: 2022-04-06
- Authors: Wang, Zixiao
- Date: 2022-04-06
- Subjects: Stock exchanges , Johannesburg Stock Exchange , Global Financial Crisis, 2008-2009 , COVID-19 (Disease) Economic aspects , Economic forecasting , Stock exchanges and current events , GARCH model
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/284603 , vital:56078
- Description: This research analyses the comparative behaviour of stock market volatility during two crises. The goal of this research is to determine whether assumed cyclical and defensive sectors have either retained or revealed their expected properties during both the Global Financial Crisis (GFC) and COVID-19 by analysing sectoral volatility amid these two crises. Understanding how volatility changes amid crises helps to determine whether the volatility assumptions of diversified investment portfolios for both defensive and cyclical sectors still held given the different causes of each crisis. In turn, this knowledge can assist with risk management and portfolio allocation in stock market investments. The study can also contribute towards the enhancement of financial markets’ resistance against systemic risks through portfolio diversification, and aid government decision-making targeted at tackling the weaknesses of different economic sectors especially in times of overall economic weakness. This research makes use of the GARCH model to analyse a group of daily time series that consists of eleven sectoral indices and one benchmark index, all based on the South African stock markets. These observed series are categorised into two full sample periods, one designated to the Global Financial Crisis (January 2006 to May 2009) and the other for COVID-19 (January 2018 to May 2021). These are further divided into two sets of sub-sample periods, each made up of a pre-crisis and during-crisis. Furthermore, the dummy variables representing the occurrence of structural breaks are inserted into the full sample periods’ conditional variance equations. This is aimed at capturing the asymmetrical impact of the crises themselves on all observed series. Based on the movement of volatility persistency from pre-crisis to during-crisis for both crises, the results show that, firstly, Health Care and Consumer Goods are considered defensive Sectors. Secondly, Banks, Basic Materials, Chemicals, Telecommunications, and Financials are considered cyclical Sectors. Thirdly, Automobiles & Parts, Consumer Services, and Technology are considered indeterminable Sectors due to the inconsistent behaviour of these sectors’ volatility persistency throughout the sub-sample periods of both crises. Overall, according to the average volatility persistency, the observed series for COVID-19’s full sample period are generally less volatile than those of the GFC. However, the sub-sample periods suggest that the observed series for both pre-crisis and during-crisis periods of COVID-19 are more volatile than those same sub-samples of the Global Financial Crisis. Being able to analyse the characteristics of stock market sectors is crucial for risk management and optimal portfolio allocation of stock market investments. This can be achieved through portfolio diversification by investing in a variety of stocks, both cyclical and defensive, and adjusted over time based the needs of stock market investors. Diversified portfolios do not only serve the interests of individual investors, but can also enhance the financial markets’ overall resistance against systemic risks. , Thesis (MCom) -- Faculty of Commerce, Economics and Economic History, 2022
- Full Text:
- Date Issued: 2022-04-06
Fabrication and characterization of ciprofloxacin loaded niosomes for transtympanic delivery
- Authors: Mhlanga, Asavela
- Date: 2022-04-06
- Subjects: Drug delivery systems , Liposomes , Ciprofloxacin , Quinolone antibacterial agents , Drug carriers (Pharmacy) , Drug stability , Lamellarity , Niosomes
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/290715 , vital:56777
- Description: Ciprofloxacin (CPH) is a broad-spectrum antibiotic used to treat bone, joint, and skin infections. It is commercially available as an extended-release tablet and as a cream dosage form. CPH is a bactericidal active pharmaceutical ingredient (API) of the fluoroquinolone drug class. It inhibits deoxyribonucleic acid (DNA) replication by inhibiting bacterial DNA topoisomerase and DNA gyrase enzymes. Common adverse effects include nausea, vomiting, unusual fatigue, pale skin, and may increase the risk of tendinitis, which could be a major concern. CPH is, according to the Biopharmaceutics Classification System (BCS), classified as a BCS class IV drug exhibiting low oral bioavailability, low solubility, and intestinal permeability. CPH was chosen as a good candidate for the study because of its stability in solutions, its low molecular weight (331.4 g/mol), and its moderate lipophilicity (log P = 0.28) [16]. The use of conventional ear drops in the ear is effective, avoids hepatic first metabolism and extensive protein binding and may reduce adverse effects as a low dose may be used to achieve a therapeutic effect. However, conventional ear drops and oral antibiotics have a long onset of action and have to be taken/applied in short intervals. For convenience and assurance of a long residence time in the ear, CPH may be delivered by using a niosomal formulation, a liquid at room temperature, to allow administration into the ear without the need to constantly apply the ear drops for long periods of time. A simple, rapid, precise, accurate, reproducible, and specific reversed-phase high-performance liquid chromatography (RP-HPLC) method using ultraviolet (UV) detection for the quantitation of CPH was developed and optimized using a central composite design (CCD). The method was validated using International Conference on Harmonisation (ICH) guidelines and was found to be linear, precise, accurate, and specific for the analysis of CPH. Since the method is specific, it was used to quantify CPH in commercial and experimental formulations and monitor CPH released during in-vitro release testing. The compatibility of CPH and potential excipients was investigated during preformulation studies using Fourier transform infrared spectroscopy (FT-IR) and differential scanning calorimetry (DSC) to identify and select suitable excipients for use during formulation development activities. No apparent interactions were evident between CPH, and the excipients tested. The probe sonication method was used to manufacture CPH loaded niosomes using different surfactants/surfactant combinations, and a combination of Tween® 80: sodium lauryl sulfate (SLS) was found to be the best composition in terms of both entrapment efficiency and Zeta potential. The limits for the independent input variables used for the manufacture included amplitude, sonication time, and amount of cholesterol were determined. Design of experiments (DOE) was used to design the study. The input variables investigated included amplitude, amount of cholesterol, and sonication time. The output or responses monitored included Zeta potential, vesicle size, polydispersity index (PDI), and entrapment efficiency. Non-ionic surfactant systems are predominantly stabilized by steric stabilization, and there is only a minor electrostatic element from adsorbed hydroxyl ions. With the inclusion of SLS it is to be expected that Zeta potential will be a contributing factor. DOE using Box-Behnken design (BBD) and response surface methodology (RSM) in addition to Artificial Neural Networks (ANN) were used for the optimization of the formulation. The optimized formulation had a composition of 1 g cholesterol, 1 g of Tween® 80, 1 g of SLS and was prepared at an amplitude of 11.294 % with a sonication time of 3.304 minutes. The formulation exhibited zero-order release kinetics and had an average pH of 7.45. The formulation was stored at 4 ℃ and 25 ℃ and was assessed for vesicle size, entrapment efficiency, Zeta potential, colour, lamellarity, and PDI every 7 days for 4 weeks. The lead formulation stored at 4 ℃ was more stable than the formulation at 25 ℃ in terms of entrapment efficiency, PDI and vesicle size during the 4-week period. CPH loaded niosomes for transtympanic delivery in the treatment of otitis media were developed and optimized. The technology exhibits sustained release of CPH and has the potential for further development and optimization. , Thesis (MSc) -- Faculty of Pharmacy, Pharmacy, 2022
- Full Text:
- Date Issued: 2022-04-06
- Authors: Mhlanga, Asavela
- Date: 2022-04-06
- Subjects: Drug delivery systems , Liposomes , Ciprofloxacin , Quinolone antibacterial agents , Drug carriers (Pharmacy) , Drug stability , Lamellarity , Niosomes
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/290715 , vital:56777
- Description: Ciprofloxacin (CPH) is a broad-spectrum antibiotic used to treat bone, joint, and skin infections. It is commercially available as an extended-release tablet and as a cream dosage form. CPH is a bactericidal active pharmaceutical ingredient (API) of the fluoroquinolone drug class. It inhibits deoxyribonucleic acid (DNA) replication by inhibiting bacterial DNA topoisomerase and DNA gyrase enzymes. Common adverse effects include nausea, vomiting, unusual fatigue, pale skin, and may increase the risk of tendinitis, which could be a major concern. CPH is, according to the Biopharmaceutics Classification System (BCS), classified as a BCS class IV drug exhibiting low oral bioavailability, low solubility, and intestinal permeability. CPH was chosen as a good candidate for the study because of its stability in solutions, its low molecular weight (331.4 g/mol), and its moderate lipophilicity (log P = 0.28) [16]. The use of conventional ear drops in the ear is effective, avoids hepatic first metabolism and extensive protein binding and may reduce adverse effects as a low dose may be used to achieve a therapeutic effect. However, conventional ear drops and oral antibiotics have a long onset of action and have to be taken/applied in short intervals. For convenience and assurance of a long residence time in the ear, CPH may be delivered by using a niosomal formulation, a liquid at room temperature, to allow administration into the ear without the need to constantly apply the ear drops for long periods of time. A simple, rapid, precise, accurate, reproducible, and specific reversed-phase high-performance liquid chromatography (RP-HPLC) method using ultraviolet (UV) detection for the quantitation of CPH was developed and optimized using a central composite design (CCD). The method was validated using International Conference on Harmonisation (ICH) guidelines and was found to be linear, precise, accurate, and specific for the analysis of CPH. Since the method is specific, it was used to quantify CPH in commercial and experimental formulations and monitor CPH released during in-vitro release testing. The compatibility of CPH and potential excipients was investigated during preformulation studies using Fourier transform infrared spectroscopy (FT-IR) and differential scanning calorimetry (DSC) to identify and select suitable excipients for use during formulation development activities. No apparent interactions were evident between CPH, and the excipients tested. The probe sonication method was used to manufacture CPH loaded niosomes using different surfactants/surfactant combinations, and a combination of Tween® 80: sodium lauryl sulfate (SLS) was found to be the best composition in terms of both entrapment efficiency and Zeta potential. The limits for the independent input variables used for the manufacture included amplitude, sonication time, and amount of cholesterol were determined. Design of experiments (DOE) was used to design the study. The input variables investigated included amplitude, amount of cholesterol, and sonication time. The output or responses monitored included Zeta potential, vesicle size, polydispersity index (PDI), and entrapment efficiency. Non-ionic surfactant systems are predominantly stabilized by steric stabilization, and there is only a minor electrostatic element from adsorbed hydroxyl ions. With the inclusion of SLS it is to be expected that Zeta potential will be a contributing factor. DOE using Box-Behnken design (BBD) and response surface methodology (RSM) in addition to Artificial Neural Networks (ANN) were used for the optimization of the formulation. The optimized formulation had a composition of 1 g cholesterol, 1 g of Tween® 80, 1 g of SLS and was prepared at an amplitude of 11.294 % with a sonication time of 3.304 minutes. The formulation exhibited zero-order release kinetics and had an average pH of 7.45. The formulation was stored at 4 ℃ and 25 ℃ and was assessed for vesicle size, entrapment efficiency, Zeta potential, colour, lamellarity, and PDI every 7 days for 4 weeks. The lead formulation stored at 4 ℃ was more stable than the formulation at 25 ℃ in terms of entrapment efficiency, PDI and vesicle size during the 4-week period. CPH loaded niosomes for transtympanic delivery in the treatment of otitis media were developed and optimized. The technology exhibits sustained release of CPH and has the potential for further development and optimization. , Thesis (MSc) -- Faculty of Pharmacy, Pharmacy, 2022
- Full Text:
- Date Issued: 2022-04-06
Pharmacists’ attitudes and perception of using pictograms as a communication tool in practice
- Authors: Okeyo, Sam Juma
- Date: 2022-04-06
- Subjects: Picture-writing South Africa , Communication in public health South Africa , Pharmacists South Africa Attitudes , Health literacy South Africa , Patient education South Africa , Structural equation modeling , Theory of planned behavior
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/290693 , vital:56775
- Description: Pictograms, when used in conjunction with verbal and written information, are known to be effective in improving comprehension and recall of medicines information and in supporting communication between healthcare professionals and patients. However, pictograms are seldom used in routine pharmacy practice, and little is known about pharmacists’ opinions of pictograms and their intention to possibly incorporate pictograms into routine practice. This study aimed to investigate pharmacists’ opinions relating to pictograms as a communication tool, and, by applying the Theory of Planned Behaviour (TPB), to explore their intention to use pictograms in pharmacy practice as well as the barriers to their use. The quantitative study design involved a two-phase approach. Phase 1 was a descriptive, cross-sectional online national survey of pharmacists. The 70-item, four-section survey was primarily based on the constructs of TPB, which included attitude, intention, subjective norm, and perceived behavioural control. The last survey section recruited pharmacists for a follow-up Phase 2 survey. Following a pilot study, the survey was emailed to all pharmacists registered with the South African Pharmacy Council. Descriptive statistics for survey items were generated. Pearson correlation investigated the correlation between participant characteristics, familiarity with pictograms and use of pictograms in practice. Structural Equation Modelling (SEM) determined if there was a significant relationship between attitude, subjective norm and perceived behavioural control with intention to use pictograms. A total of 426 pharmacists responded to the Phase 1 survey. Most pharmacists were familiar with the term ‘pictogram’; however, over three-quarters of pharmacists had never observed pictograms being routinely used in a pharmacy setting. When presented with pictograms designed for a low health literate population, most pharmacists thought the design and overall look of the pictograms would be easy for most patients in South Africa to understand (71.6 ± 24.0). Two-thirds of pharmacists (65.0 ± 30.6), felt that pictograms should be used for all patient populations. More than 85% of pharmacists agreed that pictograms should be used for dosage instructions, auxiliary or additional information, warnings, and storage instructions. However, fewer (58-68%) felt that indication, side effects and risk communication information should be accompanied by pictograms. Pharmacists demonstrated positive attitudes towards using pictograms in practice (mean = 4.2 ± 0.9; range: 1 - 5), while perceived behavioural control (mean = 3.0 ± 1.2; range: 1 - 5), subjective norm (mean = 3.8 ± 1.0; range 1 - 5) and intention (mean = 3.3 ± 1.0; range 1 - 5) were all neutral. Attitude (β = -0.25, p < 0.117), however, was not a significant predictor of intention while perceived behavioural control (β = -0.83, p < 0.000) presented with a significant negative correlation with intention. Subjective norm (β = 0.57, p <0.000) was the strongest predictor of intention. Scale reliability ranged from 0.770 to 0.865 for the TPB constructs. Phase 2 aimed to expand on, and further investigate Phase 1 findings relating to current and intended pharmacist behaviour and opinions concerning pictogram usage. As Phase 2 looked to investigate issues in greater depth, questions included open-ended response options. The survey link was emailed to all pharmacists who had voluntarily offered to participate in Phase 2. Frequency data for all questions were generated, and content analysis was undertaken for the free-response comments offered by pharmacists. A total of 35 pharmacists responded to the Phase 2 survey. Most pharmacists who routinely used pictograms initiated their use with support from pharmacists’ colleagues (8/12) and their supervisor/manager (6/7). Pharmacists who stated their intention to use pictograms anticipated receiving support from their pharmacists' colleagues (18/23) and manager/supervisor (15/23). All 12 pharmacists who were routinely using pictograms reported a positive effect on patient communication, with almost all having encountered no negative aspects of using pictograms (11/12). Almost all pharmacists intending to use pictograms could foresee benefits from their use (22/23). Misinterpretation of pictograms was a prevalent barrier common to both pharmacists routinely using pictograms and to those intending to use pictograms. Increased workload was regarded as a prevalent barrier only by pharmacists intending to use pictograms. This study was the first national study of pharmacists to investigate their opinion of pictograms and their use and to adopt a theoretical approach to consider pharmacist intention to use pictograms in routine pharmacy practice. Pharmacists generally expressed positive attitudes to pictograms but showed inadequate understanding of pictogram use. Pharmacists using pictograms reported the positive effect of pictograms on their patient communication, whereas those planning to use pictograms could foresee the benefits of using pictograms despite regarding increased workload as a barrier. As the strongest predictor of intention was subjective norm, this construct should therefore be targeted to motivate pharmacists to adopt the use of pictograms. , Thesis (MPharm) -- Faculty of Pharmacy, Pharmacy, 2022
- Full Text:
- Date Issued: 2022-04-06
- Authors: Okeyo, Sam Juma
- Date: 2022-04-06
- Subjects: Picture-writing South Africa , Communication in public health South Africa , Pharmacists South Africa Attitudes , Health literacy South Africa , Patient education South Africa , Structural equation modeling , Theory of planned behavior
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/290693 , vital:56775
- Description: Pictograms, when used in conjunction with verbal and written information, are known to be effective in improving comprehension and recall of medicines information and in supporting communication between healthcare professionals and patients. However, pictograms are seldom used in routine pharmacy practice, and little is known about pharmacists’ opinions of pictograms and their intention to possibly incorporate pictograms into routine practice. This study aimed to investigate pharmacists’ opinions relating to pictograms as a communication tool, and, by applying the Theory of Planned Behaviour (TPB), to explore their intention to use pictograms in pharmacy practice as well as the barriers to their use. The quantitative study design involved a two-phase approach. Phase 1 was a descriptive, cross-sectional online national survey of pharmacists. The 70-item, four-section survey was primarily based on the constructs of TPB, which included attitude, intention, subjective norm, and perceived behavioural control. The last survey section recruited pharmacists for a follow-up Phase 2 survey. Following a pilot study, the survey was emailed to all pharmacists registered with the South African Pharmacy Council. Descriptive statistics for survey items were generated. Pearson correlation investigated the correlation between participant characteristics, familiarity with pictograms and use of pictograms in practice. Structural Equation Modelling (SEM) determined if there was a significant relationship between attitude, subjective norm and perceived behavioural control with intention to use pictograms. A total of 426 pharmacists responded to the Phase 1 survey. Most pharmacists were familiar with the term ‘pictogram’; however, over three-quarters of pharmacists had never observed pictograms being routinely used in a pharmacy setting. When presented with pictograms designed for a low health literate population, most pharmacists thought the design and overall look of the pictograms would be easy for most patients in South Africa to understand (71.6 ± 24.0). Two-thirds of pharmacists (65.0 ± 30.6), felt that pictograms should be used for all patient populations. More than 85% of pharmacists agreed that pictograms should be used for dosage instructions, auxiliary or additional information, warnings, and storage instructions. However, fewer (58-68%) felt that indication, side effects and risk communication information should be accompanied by pictograms. Pharmacists demonstrated positive attitudes towards using pictograms in practice (mean = 4.2 ± 0.9; range: 1 - 5), while perceived behavioural control (mean = 3.0 ± 1.2; range: 1 - 5), subjective norm (mean = 3.8 ± 1.0; range 1 - 5) and intention (mean = 3.3 ± 1.0; range 1 - 5) were all neutral. Attitude (β = -0.25, p < 0.117), however, was not a significant predictor of intention while perceived behavioural control (β = -0.83, p < 0.000) presented with a significant negative correlation with intention. Subjective norm (β = 0.57, p <0.000) was the strongest predictor of intention. Scale reliability ranged from 0.770 to 0.865 for the TPB constructs. Phase 2 aimed to expand on, and further investigate Phase 1 findings relating to current and intended pharmacist behaviour and opinions concerning pictogram usage. As Phase 2 looked to investigate issues in greater depth, questions included open-ended response options. The survey link was emailed to all pharmacists who had voluntarily offered to participate in Phase 2. Frequency data for all questions were generated, and content analysis was undertaken for the free-response comments offered by pharmacists. A total of 35 pharmacists responded to the Phase 2 survey. Most pharmacists who routinely used pictograms initiated their use with support from pharmacists’ colleagues (8/12) and their supervisor/manager (6/7). Pharmacists who stated their intention to use pictograms anticipated receiving support from their pharmacists' colleagues (18/23) and manager/supervisor (15/23). All 12 pharmacists who were routinely using pictograms reported a positive effect on patient communication, with almost all having encountered no negative aspects of using pictograms (11/12). Almost all pharmacists intending to use pictograms could foresee benefits from their use (22/23). Misinterpretation of pictograms was a prevalent barrier common to both pharmacists routinely using pictograms and to those intending to use pictograms. Increased workload was regarded as a prevalent barrier only by pharmacists intending to use pictograms. This study was the first national study of pharmacists to investigate their opinion of pictograms and their use and to adopt a theoretical approach to consider pharmacist intention to use pictograms in routine pharmacy practice. Pharmacists generally expressed positive attitudes to pictograms but showed inadequate understanding of pictogram use. Pharmacists using pictograms reported the positive effect of pictograms on their patient communication, whereas those planning to use pictograms could foresee the benefits of using pictograms despite regarding increased workload as a barrier. As the strongest predictor of intention was subjective norm, this construct should therefore be targeted to motivate pharmacists to adopt the use of pictograms. , Thesis (MPharm) -- Faculty of Pharmacy, Pharmacy, 2022
- Full Text:
- Date Issued: 2022-04-06
Exploring the entrepreneurial intention of students in one Higher Education Institution (HEI)
- Authors: Kenye-Duma, Ayanda Rachel
- Date: 2022-04-06
- Subjects: Entrepreneurship South Africa , Intention , Entrepreneurship Study and teaching (Higher) South Africa , Students Attitudes , Social entrepreneurship , Social capital (Sociology) , Unemployment South Africa , Entrepreneurship Development in Higher Education (EDHE)
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/284514 , vital:56070
- Description: This study was interpretive and qualitatively explored students' entrepreneurial intentions at Rhodes University. It was conducted to understand entrepreneurship among students. Understanding students' entrepreneurship is critical as entrepreneurship is touted as a reasonable response to alleviate the high unemployment in South Africa. The study explored how students became entrepreneurs (or how their entrepreneurship intentions were formed) and the factors that enhanced (enablers and barriers) and inhibited them. The significance of living with and after COVID-19, youth and graduate unemployment alleviation places entrepreneurship development by institutions of higher learning, governments and private sector in the centre of economic recovery. The establishment of the Entrepreneurship Development in Higher Education (EDHE) in 2016, highlights the commitment of the South African government, for Higher Education Institutions (HEI) to engage more in entrepreneurship and do more research to understand how students become entrepreneurs and unravel the challenges. Understanding students' entrepreneurship intentions can facilitate a supportive environment for students entrepreneurship. With “very little research about student entrepreneurship at this university” being the guiding research problem, the aim was to gain insight into the entrepreneurship intention of university students by exploring factors that influence students to become entrepreneurs. The study employed Ajzen’s Theory of Planned Behaviour to explore the entrepreneurial intentions of university students in terms of the underlying attitudes, subjective norms, and perceived behavioural control. The students who participated in the study fell into three categories of entrepreneurial intention: (i) Intending to start a business, (ii) starting a business, and (ii) those who were already operating a business. All the participants, irrespective of their stage of entrepreneurial intention, demonstrated a positive attitude and self-efficacy. All participants showed self-efficacy by identifying barriers and taking positive steps to overcome them. The main barriers were access to funding, capital, training, business opportunities with the university and lack of interaction with established entrepreneurs. The results demonstrated the close interplay of attitudes, social norms and perceived behavioural control in students’ entrepreneurial intentions. Social recognition of entrepreneurship, social capital, education and role models contributed to positive attitudes, and social norms influenced students’ entrepreneurial intentions. A supportive environment was found to be critical for nurturing entrepreneurship intentions. The study recommends a supportive climate cultivated by Rhodes University to promote entrepreneurship. The supportive environment must include the elevation of entrepreneurship in prominent offices of the university, strengthening entrepreneurship societies and interactions with established entrepreneurs, and engagement with the private sector to contribute and promote entrepreneurship among students. , Thesis (MBA) -- Faculty of Commerce, Rhodes Business School, 2022
- Full Text:
- Date Issued: 2022-04-06
- Authors: Kenye-Duma, Ayanda Rachel
- Date: 2022-04-06
- Subjects: Entrepreneurship South Africa , Intention , Entrepreneurship Study and teaching (Higher) South Africa , Students Attitudes , Social entrepreneurship , Social capital (Sociology) , Unemployment South Africa , Entrepreneurship Development in Higher Education (EDHE)
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/284514 , vital:56070
- Description: This study was interpretive and qualitatively explored students' entrepreneurial intentions at Rhodes University. It was conducted to understand entrepreneurship among students. Understanding students' entrepreneurship is critical as entrepreneurship is touted as a reasonable response to alleviate the high unemployment in South Africa. The study explored how students became entrepreneurs (or how their entrepreneurship intentions were formed) and the factors that enhanced (enablers and barriers) and inhibited them. The significance of living with and after COVID-19, youth and graduate unemployment alleviation places entrepreneurship development by institutions of higher learning, governments and private sector in the centre of economic recovery. The establishment of the Entrepreneurship Development in Higher Education (EDHE) in 2016, highlights the commitment of the South African government, for Higher Education Institutions (HEI) to engage more in entrepreneurship and do more research to understand how students become entrepreneurs and unravel the challenges. Understanding students' entrepreneurship intentions can facilitate a supportive environment for students entrepreneurship. With “very little research about student entrepreneurship at this university” being the guiding research problem, the aim was to gain insight into the entrepreneurship intention of university students by exploring factors that influence students to become entrepreneurs. The study employed Ajzen’s Theory of Planned Behaviour to explore the entrepreneurial intentions of university students in terms of the underlying attitudes, subjective norms, and perceived behavioural control. The students who participated in the study fell into three categories of entrepreneurial intention: (i) Intending to start a business, (ii) starting a business, and (ii) those who were already operating a business. All the participants, irrespective of their stage of entrepreneurial intention, demonstrated a positive attitude and self-efficacy. All participants showed self-efficacy by identifying barriers and taking positive steps to overcome them. The main barriers were access to funding, capital, training, business opportunities with the university and lack of interaction with established entrepreneurs. The results demonstrated the close interplay of attitudes, social norms and perceived behavioural control in students’ entrepreneurial intentions. Social recognition of entrepreneurship, social capital, education and role models contributed to positive attitudes, and social norms influenced students’ entrepreneurial intentions. A supportive environment was found to be critical for nurturing entrepreneurship intentions. The study recommends a supportive climate cultivated by Rhodes University to promote entrepreneurship. The supportive environment must include the elevation of entrepreneurship in prominent offices of the university, strengthening entrepreneurship societies and interactions with established entrepreneurs, and engagement with the private sector to contribute and promote entrepreneurship among students. , Thesis (MBA) -- Faculty of Commerce, Rhodes Business School, 2022
- Full Text:
- Date Issued: 2022-04-06
A laboratory simulation investigating the impact of sunglass tint on the catching performance of cricket fielders
- Authors: Nellemann, Stacy Amanda
- Date: 2022-04-06
- Subjects: Sunglasses , Cricket Physiological aspects , Cricket players , Glare , Vision , Contrast sensitivity (Vision) , Fielders (Cricket)
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/291281 , vital:56839
- Description: Background: Sunglasses are popularly worn by outdoor athletes such as cricketers. They are primarily worn to preserve ocular health due to the length of time exposed to the sun’s glare on the field. More recently, sunglasses are now worn for their purported performance-enhancing benefits supposedly allowing athletes to “see clearly, react faster and perform with confidence”. Fielders typically wear sunglasses, but it is rare to see the bowler or the batter wearing sunglasses although they are exposed to the same conditions. If sunglasses provide visual clarity for better reaction time, it is assumed this would also be beneficial for both batsmen and bowlers alike. It is interesting that although fielding plays a key role in the winning of a match, it has received very little research in comparison to the areas of batting and bowling. Research concerning sunglasses in the past has been concerned with its effect on ocular parameters such as colour vision and contrast sensitivity, with minimal research on their effect on performance, specifically on how different colour tints may affect performance such as catching in fielding. Objective: The purpose of this study was to compare the catching performance of fielders when wearing three different colour tints of sunglasses. Methods: Thirty male cricketers currently playing for Rhodes University or country districts sides in Makhanda, South Africa, who were non-habitual sunglass wearers were recruited for this study. An optician administered a pre-screening test to ensure participants did not have any visual defects that would affect the results, determining who was eligible to continue with the research project. Twenty-five participants qualified with a further four withdrawing during the experimentation phase due to personal reasons. Eligible participants were required to complete four testing sessions on separate days thereafter in which they wore a different colour tint at each session (clear, blue, G30 and red). These tints were randomised among participants. Participants were required to catch 18 balls projected from a bowling machine in each session. The number of balls caught as well as the quality of catch was recorded. At the end of the fourth session, participants were presented with a questionnaire investigating their subjective experience of the protocol and preference for any particular colour of lens. Results: Statistically significant results were found between the different colour lenses for the ocular parameters of contrast sensitivity and stereopsis tested by the optician. The red lens was found to be the best for contrast sensitivity with the blue lens performing the worst on this test. With regard to stereopsis, the G30 lens was the worst, with the red lens performing the best. The performance measures resulted in no significant difference between the different colour lenses both concerning the total number of catches taken as well as the quality of catch taken. The same result was found irrespective of the colour of lens used in each session. Data gathered from the questionnaire regarding visual comfort and target visibility resulted in the red lens being rated statistically worse than the other three conditions. In terms of personal preference, the G30 lens was rated statistically as the best coloured lens. Conclusion: It can be concluded that objectively there is no difference in performance between the three coloured lenses. Although from an ocular perspective, the red lens was expected to perform the best in terms of catching performance, there was no difference. Subjectively there was a strong preference among the players for the G30 lens with players strongly disliking the red lens. , Thesis (MSc) -- Faculty of Science, Human Kinetics and Ergonomics, 2022
- Full Text:
- Date Issued: 2022-04-06
- Authors: Nellemann, Stacy Amanda
- Date: 2022-04-06
- Subjects: Sunglasses , Cricket Physiological aspects , Cricket players , Glare , Vision , Contrast sensitivity (Vision) , Fielders (Cricket)
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/291281 , vital:56839
- Description: Background: Sunglasses are popularly worn by outdoor athletes such as cricketers. They are primarily worn to preserve ocular health due to the length of time exposed to the sun’s glare on the field. More recently, sunglasses are now worn for their purported performance-enhancing benefits supposedly allowing athletes to “see clearly, react faster and perform with confidence”. Fielders typically wear sunglasses, but it is rare to see the bowler or the batter wearing sunglasses although they are exposed to the same conditions. If sunglasses provide visual clarity for better reaction time, it is assumed this would also be beneficial for both batsmen and bowlers alike. It is interesting that although fielding plays a key role in the winning of a match, it has received very little research in comparison to the areas of batting and bowling. Research concerning sunglasses in the past has been concerned with its effect on ocular parameters such as colour vision and contrast sensitivity, with minimal research on their effect on performance, specifically on how different colour tints may affect performance such as catching in fielding. Objective: The purpose of this study was to compare the catching performance of fielders when wearing three different colour tints of sunglasses. Methods: Thirty male cricketers currently playing for Rhodes University or country districts sides in Makhanda, South Africa, who were non-habitual sunglass wearers were recruited for this study. An optician administered a pre-screening test to ensure participants did not have any visual defects that would affect the results, determining who was eligible to continue with the research project. Twenty-five participants qualified with a further four withdrawing during the experimentation phase due to personal reasons. Eligible participants were required to complete four testing sessions on separate days thereafter in which they wore a different colour tint at each session (clear, blue, G30 and red). These tints were randomised among participants. Participants were required to catch 18 balls projected from a bowling machine in each session. The number of balls caught as well as the quality of catch was recorded. At the end of the fourth session, participants were presented with a questionnaire investigating their subjective experience of the protocol and preference for any particular colour of lens. Results: Statistically significant results were found between the different colour lenses for the ocular parameters of contrast sensitivity and stereopsis tested by the optician. The red lens was found to be the best for contrast sensitivity with the blue lens performing the worst on this test. With regard to stereopsis, the G30 lens was the worst, with the red lens performing the best. The performance measures resulted in no significant difference between the different colour lenses both concerning the total number of catches taken as well as the quality of catch taken. The same result was found irrespective of the colour of lens used in each session. Data gathered from the questionnaire regarding visual comfort and target visibility resulted in the red lens being rated statistically worse than the other three conditions. In terms of personal preference, the G30 lens was rated statistically as the best coloured lens. Conclusion: It can be concluded that objectively there is no difference in performance between the three coloured lenses. Although from an ocular perspective, the red lens was expected to perform the best in terms of catching performance, there was no difference. Subjectively there was a strong preference among the players for the G30 lens with players strongly disliking the red lens. , Thesis (MSc) -- Faculty of Science, Human Kinetics and Ergonomics, 2022
- Full Text:
- Date Issued: 2022-04-06
Large and multi scale mechanistic modeling of Diels-Alder reactions
- Authors: Isamura, Bienfait Kabuyaya
- Date: 2022-04-06
- Subjects: Computational chemistry , Diels-Alder reaction , Python (Computer program language) , Reaction force theory , Fullerenes , Diolefins , AMADAR (Automated workflow for Mechanistic Analysis of Diels-Alder Reactions , ONIOM
- Language: English
- Type: Master's thesis , text
- Identifier: http://hdl.handle.net/10962/232317 , vital:49981
- Description: The [4+2] cycloaddition reaction between conjugated dienes and substituted alkenes is known as the Diels-Alder (DA) reaction, in honor of two German chemists, Otto Diels and Kurt Alder, who first reported this marvelous chemical transformation. The DA reaction is one of the most popular reactions in organic chemistry, allowing for the regio- and stereospecific establishment of six-membered rings with up to four stereogenic centers. This pericyclic reaction has found many applications in areas as diverse as natural products chemistry, polymer chemistry, and agrochemistry. Over the past decades, the mechanism of the Diels-Alder (DA) reaction has been the subject of numerous studies, dealing with questions as diverse as the mechanistic pathway, the synchronicity, the use of catalysts, the effect of solvents and salts, etc. On the other hand, as an example, fullerenes (and particularly [60] fullerene) have been found to act as good dienophiles in DA reactions to the extent that many functionalized fullerenes with interesting applications are still synthesized by reacting C60 with dienes. However, despite the very abundant literature about the mechanism of the DA reaction, some pertinent questions have been still pending, including, without being restricted to, the prediction of transition state (TS) geometries and the modeling of DA reactions involving large systems, such as those of C60 fullerene. It must be emphasized that TSs are not easy to predict and the main reason is that many existing algorithms require that the search is initiated from a good starting point (guess TS), which must be very similar to the actual TS. This problem is even more difficult when many TSs are to be located as may be the case in large-scale studies. Moreover, due to the large size of the C60 molecule, the usage of accurate high-level computational methods in the investigation of its reactivity towards dienes is computationally costly, implying the need to find the best threshold between accuracy and computational cost. Therefore, the present study was carried out to contribute to solving the problems of large-scale prediction of DA transition state geometries and the multi-scale modeling of C60 fullerene DA reactions. To address the first problem (large-scale prediction of TSs), we have developed a python program named “AMADAR”, which predicts an unlimited number of DA transition states, using only the SMILES strings of the cycloadducts. AMADAR is customizable and allows for the description of intramolecular DA reactions as well as systems resulting in competing paths. In addition, The AMADAR tool contains two separate modules that perform reaction force analyses and atomic decomposition of energy derivatives from the predicted Intrinsic Reaction Coordinates (IRC) paths. The performance of AMADAR was assessed using 2000 DA cycloadducts and showed a success rate of ~ 95%. Most of the errors were due to basis set inconsistencies or convergence issues that we are still working on. Furthermore, a set of 150 IRC paths generated by the AMADAR program were analyzed to get insight into the (a)synchronicity of DA reactions. This investigation confirmed that the reaction force constant 𝜅 (second derivatives of the system energy with respect to the reaction coordinate) was a good indicator of synchronicity in DA reactions. A close inspection of the profile of 𝜅 has enabled us to propose an alternative classification of DA reactions based on their synchronicity degree, in terms of (quasi)-synchronous, moderate asynchronous, asynchronous, and likely two-steps DA reactions. Natural population analyses seemed to indicate that the global maximum of the reaction force constant could be identified with the formation of all the bonds in the reaction site. Finally, the atomic resolution of energy derivatives suggested that the mechanism of the DA reaction involves two inner elementary processes associated with the formation of each C-C bond. A striking mechanistic difference between synchronous and asynchronous DA reactions emerging from this study is that, in asynchronous reactions, the driving and retarding forces are mainly caused by the fast and slow-forming bonds (elementary process) respectively, while in the case of synchronous ones both elementary processes retard and drive the process concomitantly and equivalently. Regarding the DA reaction of C60 fullerene that was considered to illustrate the problem of multiscale modeling, we have constructed 12 ONIOM2 and 10 ONIOM3 models combining five semi-empirical methods (AM1, PM3, PM3MM, PDDG, PM6) and the LDA(SVWN) functional in conjunction with the B3LYP/6-31G(d) level. Then, their accuracy and efficiency were assessed in comparison with the pure B3LYP/6-31G(d) level considering first the DA reaction between C60 and cyclopentadiene whose experimental data are available. Further, different DFT functionals were employed in place of the B3LYP functional to describe the higher-layer of the best ONIOM partition, and the results obtained were compared to experimental data. At this step, the ONIOM2(M06-2X/6-31 G(d): SVWN/STO-3G) model, where the higher layer encompasses the diene and pyracyclene portion of C60, was found to provide the best tradeoff between accuracy and cost, with respect to experimental data. This model showed errors lower than 2.6 and 2.0 kcal/mol for the estimation of the activation and reaction enthalpies respectively. We have also demonstrated, by comparing several ONIOM2(DFT/6-31G(d): SVWN/STO-3G) models, the importance of dispersion corrections in the accurate estimation of reaction and activation energies. Finally, we have considered a set of 21 dienes, including anthracene, 1,3-butadiene, 1,3-cyclopentadiene, furan, thiophene, selenothiophene, pyrrole and their mono-cyano and hydroxyl derivatives to get insight into the DA reaction of C60 using the best ONIOM2(M06-2X/6-31 G(d): SVWN/STO-3G) model. For a given diene and its derivatives, the analysis of frontier molecular orbitals provides a consistent explanation for the substituent effect on the activation barrier. It revealed that electron-donating (withdrawing) groups such as -OH (–CN) cut down on the activation barrier of the reaction by lowering (extending) of the HOMOdiene – LUMOC60 gap and consequently enhancing (weakening) the interaction between the two reactants. Further, the decomposition of the activation energy into the strain and interaction components suggested that, for a given diene, electron-donating groups (here –OH) diminish the height of the activation barrier not only by favoring the attractive interaction between the diene and C60, but also by reducing the strain energy of the system; the opposite effect is observed for electron-withdrawing groups (here –CN). In contrast with some previous findings on typical DA reactions, we could not infer any general rule applicable to the entire dataset for the prediction of activation energies because the latter does not correlate well with either of the TS polarity, electrophilicity of the diene, or the reaction energy. , Thesis (MSc) -- Faculty of Science, Chemistry, 2022
- Full Text:
- Date Issued: 2022-04-06
- Authors: Isamura, Bienfait Kabuyaya
- Date: 2022-04-06
- Subjects: Computational chemistry , Diels-Alder reaction , Python (Computer program language) , Reaction force theory , Fullerenes , Diolefins , AMADAR (Automated workflow for Mechanistic Analysis of Diels-Alder Reactions , ONIOM
- Language: English
- Type: Master's thesis , text
- Identifier: http://hdl.handle.net/10962/232317 , vital:49981
- Description: The [4+2] cycloaddition reaction between conjugated dienes and substituted alkenes is known as the Diels-Alder (DA) reaction, in honor of two German chemists, Otto Diels and Kurt Alder, who first reported this marvelous chemical transformation. The DA reaction is one of the most popular reactions in organic chemistry, allowing for the regio- and stereospecific establishment of six-membered rings with up to four stereogenic centers. This pericyclic reaction has found many applications in areas as diverse as natural products chemistry, polymer chemistry, and agrochemistry. Over the past decades, the mechanism of the Diels-Alder (DA) reaction has been the subject of numerous studies, dealing with questions as diverse as the mechanistic pathway, the synchronicity, the use of catalysts, the effect of solvents and salts, etc. On the other hand, as an example, fullerenes (and particularly [60] fullerene) have been found to act as good dienophiles in DA reactions to the extent that many functionalized fullerenes with interesting applications are still synthesized by reacting C60 with dienes. However, despite the very abundant literature about the mechanism of the DA reaction, some pertinent questions have been still pending, including, without being restricted to, the prediction of transition state (TS) geometries and the modeling of DA reactions involving large systems, such as those of C60 fullerene. It must be emphasized that TSs are not easy to predict and the main reason is that many existing algorithms require that the search is initiated from a good starting point (guess TS), which must be very similar to the actual TS. This problem is even more difficult when many TSs are to be located as may be the case in large-scale studies. Moreover, due to the large size of the C60 molecule, the usage of accurate high-level computational methods in the investigation of its reactivity towards dienes is computationally costly, implying the need to find the best threshold between accuracy and computational cost. Therefore, the present study was carried out to contribute to solving the problems of large-scale prediction of DA transition state geometries and the multi-scale modeling of C60 fullerene DA reactions. To address the first problem (large-scale prediction of TSs), we have developed a python program named “AMADAR”, which predicts an unlimited number of DA transition states, using only the SMILES strings of the cycloadducts. AMADAR is customizable and allows for the description of intramolecular DA reactions as well as systems resulting in competing paths. In addition, The AMADAR tool contains two separate modules that perform reaction force analyses and atomic decomposition of energy derivatives from the predicted Intrinsic Reaction Coordinates (IRC) paths. The performance of AMADAR was assessed using 2000 DA cycloadducts and showed a success rate of ~ 95%. Most of the errors were due to basis set inconsistencies or convergence issues that we are still working on. Furthermore, a set of 150 IRC paths generated by the AMADAR program were analyzed to get insight into the (a)synchronicity of DA reactions. This investigation confirmed that the reaction force constant 𝜅 (second derivatives of the system energy with respect to the reaction coordinate) was a good indicator of synchronicity in DA reactions. A close inspection of the profile of 𝜅 has enabled us to propose an alternative classification of DA reactions based on their synchronicity degree, in terms of (quasi)-synchronous, moderate asynchronous, asynchronous, and likely two-steps DA reactions. Natural population analyses seemed to indicate that the global maximum of the reaction force constant could be identified with the formation of all the bonds in the reaction site. Finally, the atomic resolution of energy derivatives suggested that the mechanism of the DA reaction involves two inner elementary processes associated with the formation of each C-C bond. A striking mechanistic difference between synchronous and asynchronous DA reactions emerging from this study is that, in asynchronous reactions, the driving and retarding forces are mainly caused by the fast and slow-forming bonds (elementary process) respectively, while in the case of synchronous ones both elementary processes retard and drive the process concomitantly and equivalently. Regarding the DA reaction of C60 fullerene that was considered to illustrate the problem of multiscale modeling, we have constructed 12 ONIOM2 and 10 ONIOM3 models combining five semi-empirical methods (AM1, PM3, PM3MM, PDDG, PM6) and the LDA(SVWN) functional in conjunction with the B3LYP/6-31G(d) level. Then, their accuracy and efficiency were assessed in comparison with the pure B3LYP/6-31G(d) level considering first the DA reaction between C60 and cyclopentadiene whose experimental data are available. Further, different DFT functionals were employed in place of the B3LYP functional to describe the higher-layer of the best ONIOM partition, and the results obtained were compared to experimental data. At this step, the ONIOM2(M06-2X/6-31 G(d): SVWN/STO-3G) model, where the higher layer encompasses the diene and pyracyclene portion of C60, was found to provide the best tradeoff between accuracy and cost, with respect to experimental data. This model showed errors lower than 2.6 and 2.0 kcal/mol for the estimation of the activation and reaction enthalpies respectively. We have also demonstrated, by comparing several ONIOM2(DFT/6-31G(d): SVWN/STO-3G) models, the importance of dispersion corrections in the accurate estimation of reaction and activation energies. Finally, we have considered a set of 21 dienes, including anthracene, 1,3-butadiene, 1,3-cyclopentadiene, furan, thiophene, selenothiophene, pyrrole and their mono-cyano and hydroxyl derivatives to get insight into the DA reaction of C60 using the best ONIOM2(M06-2X/6-31 G(d): SVWN/STO-3G) model. For a given diene and its derivatives, the analysis of frontier molecular orbitals provides a consistent explanation for the substituent effect on the activation barrier. It revealed that electron-donating (withdrawing) groups such as -OH (–CN) cut down on the activation barrier of the reaction by lowering (extending) of the HOMOdiene – LUMOC60 gap and consequently enhancing (weakening) the interaction between the two reactants. Further, the decomposition of the activation energy into the strain and interaction components suggested that, for a given diene, electron-donating groups (here –OH) diminish the height of the activation barrier not only by favoring the attractive interaction between the diene and C60, but also by reducing the strain energy of the system; the opposite effect is observed for electron-withdrawing groups (here –CN). In contrast with some previous findings on typical DA reactions, we could not infer any general rule applicable to the entire dataset for the prediction of activation energies because the latter does not correlate well with either of the TS polarity, electrophilicity of the diene, or the reaction energy. , Thesis (MSc) -- Faculty of Science, Chemistry, 2022
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- Date Issued: 2022-04-06