Green Synthesis of HIV-1 Protease Inhibitors
- Authors: Hartley, Shaun Neil
- Date: 2021-10
- Subjects: Uncatalogued
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/190145 , vital:44967
- Description: Thesis embargoed until October 2022 , Thesis (MSc) -- Faculty of Science, Chemistry, 2021
- Full Text:
- Date Issued: 2021-10
- Authors: Hartley, Shaun Neil
- Date: 2021-10
- Subjects: Uncatalogued
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/190145 , vital:44967
- Description: Thesis embargoed until October 2022 , Thesis (MSc) -- Faculty of Science, Chemistry, 2021
- Full Text:
- Date Issued: 2021-10
Assessing South African medical interns’ experience and confidence in managing obstetric emergencies
- Date: 2021-10
- Subjects: Interns (Medicine) Obstetrical emergencies Article
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/11260/7629 , vital:54737 , ("https://10.7196/SAMJ.2021.v111i11.15897")
- Description: Background. Medical doctors in South Africa (SA) are required to complete a 2-year internship at training hospitals, including a 4-month rotation in obstetrics and gynaecology. Following this, doctors are allocated to community service posts, many of which are at district- and primary-level facilities where supervision is limited. Recent triennial Saving Mothers reports identify district hospitals (DHs) as the second leading site for maternal deaths of all causes, the leading site for maternal deaths secondary to obstetric haemorrhage, and the most likely site for the lack of a skilled doctor to be identified as a factor in deaths associated with caesarean delivery. Objectives. To describe the self-perceived readiness of medical interns completing their training to manage obstetric emergencies, based on the Essential Steps in the Management of Obstetric Emergencies modules in the Health Professions Council of South Africa’s internship logbook. Methods. This cross-sectional descriptive study assessed medical interns in the last 3 months of their training, using a self-administered online questionnaire. Data collection took place between October and December 2019. Results. Cluster sampling of interns at training facilities throughout SA resulted in a total of 182 respondents from 17 hospitals in seven provinces in the country, with an overall response rate of 34.1%. Most interns had experience with and confidence in the management of miscarriage and hypertension in pregnancy. However, gaps in labour ward management, pregnancy-related sepsis and surgical skills were identified. Only 42.3% of respondents were confident in their ability to diagnose obstructed labour, 26.3% had performed an assisted delivery, 39.0% were confident in their knowledge of the indications for and contraindications to assisted deliveries, and 35.7% had been involved in the delivery of a baby with shoulder dystocia. Regarding pregnancy-related sepsis, 54.4% had experience with managing a wound abscess and 29.7% were confident managing puerperal endometritis. While 78.0% felt confident to perform a caesarean section (CS), only 28.6% had performed uterine compression suture for uterine atony at CS. Additionally, there was a statistically significant variation in scores between training hospitals. Conclusions. An incongruity exists between the shortcomings in DH obstetric services, the prioritisation of placement of community service doctors at primary healthcare facilities and DHs, and the self-perceived readiness of medical interns completing their training to manage obstetric emergencies safely. This situation highlights the importance of clinical support for junior doctors at DHs and standardisation of intern training at accredited facilities across SA.
- Full Text:
- Date Issued: 2021-10
Assessing South African medical interns’ experience and confidence in managing obstetric emergencies
- Date: 2021-10
- Subjects: Interns (Medicine) Obstetrical emergencies Article
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/11260/7629 , vital:54737 , ("https://10.7196/SAMJ.2021.v111i11.15897")
- Description: Background. Medical doctors in South Africa (SA) are required to complete a 2-year internship at training hospitals, including a 4-month rotation in obstetrics and gynaecology. Following this, doctors are allocated to community service posts, many of which are at district- and primary-level facilities where supervision is limited. Recent triennial Saving Mothers reports identify district hospitals (DHs) as the second leading site for maternal deaths of all causes, the leading site for maternal deaths secondary to obstetric haemorrhage, and the most likely site for the lack of a skilled doctor to be identified as a factor in deaths associated with caesarean delivery. Objectives. To describe the self-perceived readiness of medical interns completing their training to manage obstetric emergencies, based on the Essential Steps in the Management of Obstetric Emergencies modules in the Health Professions Council of South Africa’s internship logbook. Methods. This cross-sectional descriptive study assessed medical interns in the last 3 months of their training, using a self-administered online questionnaire. Data collection took place between October and December 2019. Results. Cluster sampling of interns at training facilities throughout SA resulted in a total of 182 respondents from 17 hospitals in seven provinces in the country, with an overall response rate of 34.1%. Most interns had experience with and confidence in the management of miscarriage and hypertension in pregnancy. However, gaps in labour ward management, pregnancy-related sepsis and surgical skills were identified. Only 42.3% of respondents were confident in their ability to diagnose obstructed labour, 26.3% had performed an assisted delivery, 39.0% were confident in their knowledge of the indications for and contraindications to assisted deliveries, and 35.7% had been involved in the delivery of a baby with shoulder dystocia. Regarding pregnancy-related sepsis, 54.4% had experience with managing a wound abscess and 29.7% were confident managing puerperal endometritis. While 78.0% felt confident to perform a caesarean section (CS), only 28.6% had performed uterine compression suture for uterine atony at CS. Additionally, there was a statistically significant variation in scores between training hospitals. Conclusions. An incongruity exists between the shortcomings in DH obstetric services, the prioritisation of placement of community service doctors at primary healthcare facilities and DHs, and the self-perceived readiness of medical interns completing their training to manage obstetric emergencies safely. This situation highlights the importance of clinical support for junior doctors at DHs and standardisation of intern training at accredited facilities across SA.
- Full Text:
- Date Issued: 2021-10
Knowledge, Attitudes and Perceptions Towards HIV Testing Among IsiXhosa-Speaking Men in The Zithulele Catchment Area of The Rural Eastern Cape Province, South Africa
- Authors: Scotcher, Philippa Claire
- Date: 2021-10
- Subjects: HIV infections
- Language: English
- Type: Masters theses , text
- Identifier: http://hdl.handle.net/11260/6842 , vital:51017
- Description: BACKGROUND South Africa carries the largest burden of Human Immunodeficiency Virus (HIV) in the world, with over 7.9 million people infected and over 70 000 HIV-related deaths in 2019. Men are 25% more likely to die from Acquired Immune Deficiency Syndrome (AIDS) compared to women, even though women are more likely to be infected. Despite these numbers, only 24.1% of HIV-positive men compared to 64.8% of HIV-positive women were aware of their status. Statistics indicate that men in South Africa are not testing for HIV until it is too late. In order to focus efforts on the prevention of HIV transmission, there is a need to understand why men are not accessing HIV testing and treatment services earlier. This study aims to explore the knowledge, attitudes, and perceptions towards HIV testing of isiXhosa-speaking men in the Zithulele catchment area of the rural Eastern Cape. METHODS This was a qualitative study using the phenomenological approach. It was conducted among a purposive sample of isiXhosa-speaking men from the Zithulele catchment area, in the OR Tambo district of the Eastern Cape Province. Ten semi-structured interviews and one focus group were conducted in isiXhosa. Interviews were audiorecorded, transcribed, and translated into English. The interviews were thematically analysed using an inductive approach. RESULTS Participants from the study had a good understanding of HIV and HIV transmission. They perceived HIV infection as a death sentence, a consequence of immoral behaviour and an indication of failure as man. Reluctance to test for HIV was due to the perception that testing hastens the onset of symptoms and death, whereas disclosure of an HIV-positive status was described as difficult due to the fear of stigmatization. Some of the barriers to accessing HIV testing services included masculine norms, the belief that sickness is equated with weakness, a perceived lack of confidentiality at health facilities and how female-dominated clinics were not male-friendly spaces. Suggestions to improve HIV testing among men included improving targeted education, home-based testing services and utilizing traditional meetings to address men. CONCLUSION The findings of this study may suggest that healthy men in the Zithulele catchment area of the rural Eastern Cape are not accessing HIV testing and treatment services. The reasons behind this reluctance include false beliefs around HIV and testing, the fear of discrimination, disruption of masculine norms and reluctance to access care at female-dominated health facilities. Further research is needed to explore ways to reach, educate and encourage men to test earlier for HIV. , Thesis (Masters) -- Faculty of Health Sciences, 2021
- Full Text:
- Date Issued: 2021-10
- Authors: Scotcher, Philippa Claire
- Date: 2021-10
- Subjects: HIV infections
- Language: English
- Type: Masters theses , text
- Identifier: http://hdl.handle.net/11260/6842 , vital:51017
- Description: BACKGROUND South Africa carries the largest burden of Human Immunodeficiency Virus (HIV) in the world, with over 7.9 million people infected and over 70 000 HIV-related deaths in 2019. Men are 25% more likely to die from Acquired Immune Deficiency Syndrome (AIDS) compared to women, even though women are more likely to be infected. Despite these numbers, only 24.1% of HIV-positive men compared to 64.8% of HIV-positive women were aware of their status. Statistics indicate that men in South Africa are not testing for HIV until it is too late. In order to focus efforts on the prevention of HIV transmission, there is a need to understand why men are not accessing HIV testing and treatment services earlier. This study aims to explore the knowledge, attitudes, and perceptions towards HIV testing of isiXhosa-speaking men in the Zithulele catchment area of the rural Eastern Cape. METHODS This was a qualitative study using the phenomenological approach. It was conducted among a purposive sample of isiXhosa-speaking men from the Zithulele catchment area, in the OR Tambo district of the Eastern Cape Province. Ten semi-structured interviews and one focus group were conducted in isiXhosa. Interviews were audiorecorded, transcribed, and translated into English. The interviews were thematically analysed using an inductive approach. RESULTS Participants from the study had a good understanding of HIV and HIV transmission. They perceived HIV infection as a death sentence, a consequence of immoral behaviour and an indication of failure as man. Reluctance to test for HIV was due to the perception that testing hastens the onset of symptoms and death, whereas disclosure of an HIV-positive status was described as difficult due to the fear of stigmatization. Some of the barriers to accessing HIV testing services included masculine norms, the belief that sickness is equated with weakness, a perceived lack of confidentiality at health facilities and how female-dominated clinics were not male-friendly spaces. Suggestions to improve HIV testing among men included improving targeted education, home-based testing services and utilizing traditional meetings to address men. CONCLUSION The findings of this study may suggest that healthy men in the Zithulele catchment area of the rural Eastern Cape are not accessing HIV testing and treatment services. The reasons behind this reluctance include false beliefs around HIV and testing, the fear of discrimination, disruption of masculine norms and reluctance to access care at female-dominated health facilities. Further research is needed to explore ways to reach, educate and encourage men to test earlier for HIV. , Thesis (Masters) -- Faculty of Health Sciences, 2021
- Full Text:
- Date Issued: 2021-10
Evaluation of Megabruchidius tonkineus (Coleoptera: Chrysomelidae: Bruchinae), a candidate biological control agent for Gleditsia triacanthos L. (Fabaceae) in South Africa
- Salgado Astudillo, Sara Elizabeth
- Authors: Salgado Astudillo, Sara Elizabeth
- Date: 2021-10
- Subjects: Honey locust South Africa , Honey locust Biological control South Africa , Invasive plants Biological control South Africa , Biogeography South Africa , Biogeography Climatic factors South Africa , Megabruchidius tonkineus South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/188386 , vital:44749
- Description: Gleditsia triacanthos L. (Fabaceae) (honey locust) is a fast-growing, deciduous tree indigenous to the United States of America. Introduced around the world as an ornamental tree, it has become invasive in a number of countries. Where it is invasive, G. triacanthos competes and replaces indigenous species; it creates dense stands along watercourses, posing a significant environmental threat. In South Africa, G. triacanthos is regarded as one of the country’s fastest spreading weeds. Gleditsia triacanthos produces numerous seeds contained in large hanging pods. Once dislodged from the pods, the seeds are dispersed by birds and mammals, including livestock, which eat the pods. It has been suggested that the seeds should be the target for biological control programme. Some invasive alien plant species are characterised by their ability to spread and establish in new ecosystems because they tolerate a wide range of environmental conditions. In order to predict areas of likely invasion, species distribution models (SDMs) are used to identify areas climatically suitable for their invasion, so enabling better targeted control of the plant species. Gleditsia triacanthos adapts to a wide range of climates and soil types, and tolerates salinity, drought and frost. Currently primarily restricted to the Grassland Biome of South Africa, G. triacanthos has doubled its distribution area in the past 15 years, and it is not known how far the species will spread. In this study we used two different modelling programmes, CLIMEX and MaxEnt, to predict areas where G. triacanthos could find favourable growing conditions; both SDMs showed that most of the country is suitable for G. triacanthos and that it will probably continue to spread, if left unmanaged, into new bioregions, such as the Karoo. In South Africa, the Asian seed-feeding bruchid, Megabruchidius tonkineus (Pic, 1914) (Coleoptera: Chrysomelidae: Bruchinae) has been recorded in the plant’s seed pods and has been considered as a biological control agent. The insect was not released as part of a formal biological control programme and neither host-specificity nor impact studies were conducted on the species prior to its discovery. In 2017 a decision was made to re-consider its status as a Abstract biological control agent until further details of its biology, host specificity, and impact on the seeds of G. triacanthos in South Africa were available. This study shows that Megabruchidius tonkineus has established across the entire G. triacanthos population in South Africa damaging approximately 9% of seeds. Laboratory studies show that, Megabruchidius tonkineus completes its larval development in the seeds of G. triacanthos in about 66.80 ± 0.6880 SE days before eclosing. In addition, the adult females oviposit on the following Fabaceae species: Arachis hypogaea, Albizia, julibrissin, Cicer arietinum, Pisum sativum, Dipogon lignosus, Peltophorum africanum, Podalyria buxifolia Senegalia burkei, Umtiza listerina and Vachellia sieberiana. However, larval development was limited to G. triacanthos. It is concluded that the seed-feeding beetle is not a threat to native Fabaceae species in South Africa, however, it does not damage enough G. triacanthos seeds to be considered a valuable biological control agent at this stage, and additional seed-feeding biological control agents should be considered to reduce the number of G. triacanthos seeds entering the environment. , Thesis (MSc) -- Faculty of Science, Zoology and Entomology, 2021
- Full Text:
- Date Issued: 2021-10
- Authors: Salgado Astudillo, Sara Elizabeth
- Date: 2021-10
- Subjects: Honey locust South Africa , Honey locust Biological control South Africa , Invasive plants Biological control South Africa , Biogeography South Africa , Biogeography Climatic factors South Africa , Megabruchidius tonkineus South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/188386 , vital:44749
- Description: Gleditsia triacanthos L. (Fabaceae) (honey locust) is a fast-growing, deciduous tree indigenous to the United States of America. Introduced around the world as an ornamental tree, it has become invasive in a number of countries. Where it is invasive, G. triacanthos competes and replaces indigenous species; it creates dense stands along watercourses, posing a significant environmental threat. In South Africa, G. triacanthos is regarded as one of the country’s fastest spreading weeds. Gleditsia triacanthos produces numerous seeds contained in large hanging pods. Once dislodged from the pods, the seeds are dispersed by birds and mammals, including livestock, which eat the pods. It has been suggested that the seeds should be the target for biological control programme. Some invasive alien plant species are characterised by their ability to spread and establish in new ecosystems because they tolerate a wide range of environmental conditions. In order to predict areas of likely invasion, species distribution models (SDMs) are used to identify areas climatically suitable for their invasion, so enabling better targeted control of the plant species. Gleditsia triacanthos adapts to a wide range of climates and soil types, and tolerates salinity, drought and frost. Currently primarily restricted to the Grassland Biome of South Africa, G. triacanthos has doubled its distribution area in the past 15 years, and it is not known how far the species will spread. In this study we used two different modelling programmes, CLIMEX and MaxEnt, to predict areas where G. triacanthos could find favourable growing conditions; both SDMs showed that most of the country is suitable for G. triacanthos and that it will probably continue to spread, if left unmanaged, into new bioregions, such as the Karoo. In South Africa, the Asian seed-feeding bruchid, Megabruchidius tonkineus (Pic, 1914) (Coleoptera: Chrysomelidae: Bruchinae) has been recorded in the plant’s seed pods and has been considered as a biological control agent. The insect was not released as part of a formal biological control programme and neither host-specificity nor impact studies were conducted on the species prior to its discovery. In 2017 a decision was made to re-consider its status as a Abstract biological control agent until further details of its biology, host specificity, and impact on the seeds of G. triacanthos in South Africa were available. This study shows that Megabruchidius tonkineus has established across the entire G. triacanthos population in South Africa damaging approximately 9% of seeds. Laboratory studies show that, Megabruchidius tonkineus completes its larval development in the seeds of G. triacanthos in about 66.80 ± 0.6880 SE days before eclosing. In addition, the adult females oviposit on the following Fabaceae species: Arachis hypogaea, Albizia, julibrissin, Cicer arietinum, Pisum sativum, Dipogon lignosus, Peltophorum africanum, Podalyria buxifolia Senegalia burkei, Umtiza listerina and Vachellia sieberiana. However, larval development was limited to G. triacanthos. It is concluded that the seed-feeding beetle is not a threat to native Fabaceae species in South Africa, however, it does not damage enough G. triacanthos seeds to be considered a valuable biological control agent at this stage, and additional seed-feeding biological control agents should be considered to reduce the number of G. triacanthos seeds entering the environment. , Thesis (MSc) -- Faculty of Science, Zoology and Entomology, 2021
- Full Text:
- Date Issued: 2021-10
Investigating the feasibility of using remote sensing in index-based crop insurance for South Africa’s smallholder farming systems
- Masiza, Wonga https://orcid.org/0000-0002-6224-3812
- Authors: Masiza, Wonga https://orcid.org/0000-0002-6224-3812
- Date: 2021-10
- Subjects: Precision farming , Agricultural engineering , Climatic changes
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/23000 , vital:54890
- Description: Crop farming in Sub-Saharan Africa (SSA) is largely practiced by resource-poor farmers under rain-fed and unpredictable weather conditions. Since agriculture is the mainstay of SSA’s economy, the lack of improved and adapted agricultural technologies in this region sets back economic development and the fight against poverty. Overcoming this constraint and achieving the sustainable development goal to end poverty, requires innovative tools that can be used for weather risk management. One tool that has been gaining momentum recently is index-based crop insurance (IBCI). Since the launch of the first IBCI program in Africa around 2005, the number of IBCI programs has increased. Unfortunately, these programs are constrained by poor product design, basis risk, and low uptake of contracts. When these issues were first pointed-out in the earliest IBCI programs, many reports suggested satellite remote sensing (RS) as a viable solution. Hence, the first objective of this study was to assess how RS has been used in IBCI, the challenges RS faces, and potential contributions of RS that have not yet been meaningfully exploited. The literature shows that IBCI programs are increasingly adopting RS. RS has improved demarcation of unit areas of insurance and enabled IBCI to reach inaccessible areas that do not have sufficient meteorological infrastructure. However, the literature also shows that IBCI is still tainted by basis risk, which emanates from poor contract designs, the influence of non-weather factors on crop yields, imperfect correlations between satellite-based indices and crop yields, and the lack of historical data for calibration. Although IBCI reports cover vegetation and crop health monitoring, few to none cover crop type and crop area mapping. Furthermore, areas including high-resolution mapping, data fusion, microwave RS, machine learning, and computer vision have not been sufficiently tested in IBCI. The second objective of this study was to assess how RS and machine learning techniques can be used to enhance the mapping of smallholder crop farming landscapes. The findings show that machine learning ensembles and the combination of optical and microwave data can map a smallholder farming landscape with a maximum accuracy of 97.71 percent. The third objective was to identify factors that influence crop yields and crop losses in order to improve IBCI design. Results demonstrated that the pervasive notion that low yields in smallholder farms are related to rainfall is an oversimplification. Factors including fertilizer use, seed variety, soil properties, soil moisture, growing degree-days, management, and socioeconomic conditions are some of the most important factors influencing crop yields and crop losses in smallholder farming systems. This shows why IBCI needs to be part of a comprehensive risk management system that understands and approaches smallholder crop farming as complex by linking insurance with advisories and input supplies. Improved inputs and good farming practices could reduce the influence of non-weather factors on crop losses, and thereby reduce basis risk in weather-based index insurance (WII) contracts. The fourth objective of this study was to assess how well the combination of synthetic aperture radar (SAR) and optical indices estimate soil moisture. As stated earlier, soil moisture was found to be one of the most important factors affecting crop yields. Although this method better estimated soil moisture over the first half of the growing season, estimation accuracies were comparable to those found in studies that had used similar datasets (RMSE = 0.043 m3 m-3, MAE = 0.034 m3 m- 3). Further interrogation of interaction effects between the variables used in this study and consideration of other factors that affect SAR backscatter could improve the method. More importantly, incorporating high-resolution satellite-based monitoring of soil moisture into IBCI could potentially reduce basis risk. The fifth objective of this study was to develop an IBCI for smallholder crop farming systems. The proposed IBCI scheme covers maize and derives index thresholds from crop water requirements and satellite-based rainfall estimates. It covers rainfall deficits over the vegetative, mid-season, and late-season stages of maize growth. The key contribution of this system is the derivation of index thresholds from CWR and site-specific rainfall conditions. The widely used approach, which calibrates IBCI by correlating yields and rainfall, exposes contracts to basis risk because, by simply correlating yield and rainfall data, it overlooks the influence of non-weather factors on crop yields and losses. The proposed system must be linked or bundled with non-weather variables that affect crop yields. Effectively, this means that the insurance must be linked or bundled with advisories and input supplies to address the influence of non-weather factors on crop losses. This system also incorporates a crop area-mapping component, which was found to be lacking in many IBCI systems. In conclusion, an IBCI that is based on crop water requirements, which incorporates crop area mapping and links insurance with non-weather crop yield-determining factors, is potentially capable of improving crop insurance for smallholder farming systems. , Thesis (PhD) -- Faculty of Science and Agriculture, 2021
- Full Text:
- Date Issued: 2021-10
- Authors: Masiza, Wonga https://orcid.org/0000-0002-6224-3812
- Date: 2021-10
- Subjects: Precision farming , Agricultural engineering , Climatic changes
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/23000 , vital:54890
- Description: Crop farming in Sub-Saharan Africa (SSA) is largely practiced by resource-poor farmers under rain-fed and unpredictable weather conditions. Since agriculture is the mainstay of SSA’s economy, the lack of improved and adapted agricultural technologies in this region sets back economic development and the fight against poverty. Overcoming this constraint and achieving the sustainable development goal to end poverty, requires innovative tools that can be used for weather risk management. One tool that has been gaining momentum recently is index-based crop insurance (IBCI). Since the launch of the first IBCI program in Africa around 2005, the number of IBCI programs has increased. Unfortunately, these programs are constrained by poor product design, basis risk, and low uptake of contracts. When these issues were first pointed-out in the earliest IBCI programs, many reports suggested satellite remote sensing (RS) as a viable solution. Hence, the first objective of this study was to assess how RS has been used in IBCI, the challenges RS faces, and potential contributions of RS that have not yet been meaningfully exploited. The literature shows that IBCI programs are increasingly adopting RS. RS has improved demarcation of unit areas of insurance and enabled IBCI to reach inaccessible areas that do not have sufficient meteorological infrastructure. However, the literature also shows that IBCI is still tainted by basis risk, which emanates from poor contract designs, the influence of non-weather factors on crop yields, imperfect correlations between satellite-based indices and crop yields, and the lack of historical data for calibration. Although IBCI reports cover vegetation and crop health monitoring, few to none cover crop type and crop area mapping. Furthermore, areas including high-resolution mapping, data fusion, microwave RS, machine learning, and computer vision have not been sufficiently tested in IBCI. The second objective of this study was to assess how RS and machine learning techniques can be used to enhance the mapping of smallholder crop farming landscapes. The findings show that machine learning ensembles and the combination of optical and microwave data can map a smallholder farming landscape with a maximum accuracy of 97.71 percent. The third objective was to identify factors that influence crop yields and crop losses in order to improve IBCI design. Results demonstrated that the pervasive notion that low yields in smallholder farms are related to rainfall is an oversimplification. Factors including fertilizer use, seed variety, soil properties, soil moisture, growing degree-days, management, and socioeconomic conditions are some of the most important factors influencing crop yields and crop losses in smallholder farming systems. This shows why IBCI needs to be part of a comprehensive risk management system that understands and approaches smallholder crop farming as complex by linking insurance with advisories and input supplies. Improved inputs and good farming practices could reduce the influence of non-weather factors on crop losses, and thereby reduce basis risk in weather-based index insurance (WII) contracts. The fourth objective of this study was to assess how well the combination of synthetic aperture radar (SAR) and optical indices estimate soil moisture. As stated earlier, soil moisture was found to be one of the most important factors affecting crop yields. Although this method better estimated soil moisture over the first half of the growing season, estimation accuracies were comparable to those found in studies that had used similar datasets (RMSE = 0.043 m3 m-3, MAE = 0.034 m3 m- 3). Further interrogation of interaction effects between the variables used in this study and consideration of other factors that affect SAR backscatter could improve the method. More importantly, incorporating high-resolution satellite-based monitoring of soil moisture into IBCI could potentially reduce basis risk. The fifth objective of this study was to develop an IBCI for smallholder crop farming systems. The proposed IBCI scheme covers maize and derives index thresholds from crop water requirements and satellite-based rainfall estimates. It covers rainfall deficits over the vegetative, mid-season, and late-season stages of maize growth. The key contribution of this system is the derivation of index thresholds from CWR and site-specific rainfall conditions. The widely used approach, which calibrates IBCI by correlating yields and rainfall, exposes contracts to basis risk because, by simply correlating yield and rainfall data, it overlooks the influence of non-weather factors on crop yields and losses. The proposed system must be linked or bundled with non-weather variables that affect crop yields. Effectively, this means that the insurance must be linked or bundled with advisories and input supplies to address the influence of non-weather factors on crop losses. This system also incorporates a crop area-mapping component, which was found to be lacking in many IBCI systems. In conclusion, an IBCI that is based on crop water requirements, which incorporates crop area mapping and links insurance with non-weather crop yield-determining factors, is potentially capable of improving crop insurance for smallholder farming systems. , Thesis (PhD) -- Faculty of Science and Agriculture, 2021
- Full Text:
- Date Issued: 2021-10
An empirical analysis of the asset price monetary policy transmission channel in South Africa
- Authors: Du Preez, Wilhelmus Petrus
- Date: 2021-10
- Subjects: Monetary policy South Africa , Banks and banking, Central South Africa , Transmission mechanism (Monetary policy) South Africa , Capital assets pricing model , Securities South Africa , Stocks Prices South Africa , Repurchase agreements South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/190318 , vital:44983
- Description: The asset pricing channel of monetary policy transmission breeds an interesting study. There has been an ongoing debate to determine whether monetary policy committees should directly influence the asset pricing channel through changes in the central bank control interest rate or whether monetary policy committees should refrain from targeting the asset pricing channel to meet their policy objectives. The study aims to critically analysis the asset pricing channel, firstly on a global context to set the scene and then to critically focus on the study performed by Muroyiwa et al. (2017) who conducted a study on the South African monetary policy and its interdependence on the stock market through utilisation of an SVAR model. It was concluded that monetary policy does significantly influence stock prices. The purpose of this study is to build on the results which have been formed by Muroyiwa et al. (2017) and to expand on the period under analysis which encapsulates 1999:01 to 2007:12 in order to conclude whether there are conflicting conclusions or conclusions which build on what has already been done. The results from the research shows that when the monetary policy committee decides to influence changes in the repo rate, the repo rate will have a direct effect on the asset markets, the indexes that were used to represent the asset market are the all share index, industrial 15 index and the financial 15 index. Furthermore. The study which has expanded the period under analysis has supplemented and built on the results provided by Muroyiwa et al. (2017). , Thesis (MCom) -- Faculty of Commerce, Economics and Economic History, 2021
- Full Text:
- Date Issued: 2021-10
- Authors: Du Preez, Wilhelmus Petrus
- Date: 2021-10
- Subjects: Monetary policy South Africa , Banks and banking, Central South Africa , Transmission mechanism (Monetary policy) South Africa , Capital assets pricing model , Securities South Africa , Stocks Prices South Africa , Repurchase agreements South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/190318 , vital:44983
- Description: The asset pricing channel of monetary policy transmission breeds an interesting study. There has been an ongoing debate to determine whether monetary policy committees should directly influence the asset pricing channel through changes in the central bank control interest rate or whether monetary policy committees should refrain from targeting the asset pricing channel to meet their policy objectives. The study aims to critically analysis the asset pricing channel, firstly on a global context to set the scene and then to critically focus on the study performed by Muroyiwa et al. (2017) who conducted a study on the South African monetary policy and its interdependence on the stock market through utilisation of an SVAR model. It was concluded that monetary policy does significantly influence stock prices. The purpose of this study is to build on the results which have been formed by Muroyiwa et al. (2017) and to expand on the period under analysis which encapsulates 1999:01 to 2007:12 in order to conclude whether there are conflicting conclusions or conclusions which build on what has already been done. The results from the research shows that when the monetary policy committee decides to influence changes in the repo rate, the repo rate will have a direct effect on the asset markets, the indexes that were used to represent the asset market are the all share index, industrial 15 index and the financial 15 index. Furthermore. The study which has expanded the period under analysis has supplemented and built on the results provided by Muroyiwa et al. (2017). , Thesis (MCom) -- Faculty of Commerce, Economics and Economic History, 2021
- Full Text:
- Date Issued: 2021-10
Mobilising stories about cultural beliefs and practices on traditional foods to contextualise the topic on nutrition in a Grade 6 township class
- Authors: Nuntsu, Sipho Nimrod
- Date: 2021-10
- Subjects: Culturally relevant pedagogy South Africa , Science Study and teaching (Elementary) South Africa , Nutrition Study and teaching (Elementary) South Africa , Traditional ecological knowledge South Africa , Storytelling , Reasoning , Contiguity Argumentation Theory (CAT) , South African Curriculum Assessment and Policy Statement (CAPS) , Socio-cultural theory
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/190940 , vital:45043
- Description: The South African Curriculum Assessment and Policy Statement (CAPS) document stipulates that science teachers should integrate indigenous knowledge (IK) into their science teaching. The rationale for this is to contextualise the content and make science accessible and relevant to learners. Despite these ideals, however, CAPS seems to be silent on how science teachers should go about doing this. Instead, it assumes that all teachers know how to integrate IK in their science teaching. As a result, many teachers are still not sure of how to integrate IK into their science classrooms. Such rhetoric and tension between curriculum formulation and implementation triggered my interest to do a study on how to mobilise stories about cultural beliefs and practices of traditional foods to mediate learning of nutrition in a Grade 6 Natural Sciences township class. The study was underpinned by an interprevist paradigm complemented with an Ubuntu paradigm to enhance explanations. Within these paradigms, a qualitative case study research design was adopted. It was conducted at Mdoko Primary school (pseudonym) in a semi-urban community in the Amathole West district of the Eastern Cape. The participants were 34 Grade 6 learners (15 boys and 19 girls), a Grade 6 Natural Sciences teacher who was my critical friend, and two expert community members. To generate data, I used a focus group discussion, group activities, classroom observations, and learners’ reflective journals. Vygotsky’s socio-cultural theory and Ogunniyi’s Contiguity Argumentation Theory (CAT) were used as theoretical and analytical frameworks, respectively. A thematic approach to data analysis was employed. That is, data were analysed inductively to identify sub-themes and subsequently similar sub-themes were grouped together to form themes. The two expert community members’ presentations equipped my learners with stories on cultural beliefs and practices that were used in the olden days (past) and how such stories are used in our days (present). For instance, the findings of this study revealed that women during menstruation must not drink amasi as it is believed that it would prolong the menstruation time. The findings also revealed that eating of amaqanda and inside meat by youths should be minimised as it is believed that it can stimulate their sex hormones. It also revealed that there is no relevance to science that men eating imifino would be weak among other men who do not eat them. The implications for this study is that science teachers should make some efforts to integrate IK in their teaching to make science accessible and relevant to their learners. To achieve this, the study thus recommends that science teachers should find ways of tapping into the cultural heritage and wisdom that is possessed by the expert community members to enable learners to cross the bridge from home to school. , Thesis (MEd) -- Faculty of Education, Education, 2021
- Full Text:
- Date Issued: 2021-10
- Authors: Nuntsu, Sipho Nimrod
- Date: 2021-10
- Subjects: Culturally relevant pedagogy South Africa , Science Study and teaching (Elementary) South Africa , Nutrition Study and teaching (Elementary) South Africa , Traditional ecological knowledge South Africa , Storytelling , Reasoning , Contiguity Argumentation Theory (CAT) , South African Curriculum Assessment and Policy Statement (CAPS) , Socio-cultural theory
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/190940 , vital:45043
- Description: The South African Curriculum Assessment and Policy Statement (CAPS) document stipulates that science teachers should integrate indigenous knowledge (IK) into their science teaching. The rationale for this is to contextualise the content and make science accessible and relevant to learners. Despite these ideals, however, CAPS seems to be silent on how science teachers should go about doing this. Instead, it assumes that all teachers know how to integrate IK in their science teaching. As a result, many teachers are still not sure of how to integrate IK into their science classrooms. Such rhetoric and tension between curriculum formulation and implementation triggered my interest to do a study on how to mobilise stories about cultural beliefs and practices of traditional foods to mediate learning of nutrition in a Grade 6 Natural Sciences township class. The study was underpinned by an interprevist paradigm complemented with an Ubuntu paradigm to enhance explanations. Within these paradigms, a qualitative case study research design was adopted. It was conducted at Mdoko Primary school (pseudonym) in a semi-urban community in the Amathole West district of the Eastern Cape. The participants were 34 Grade 6 learners (15 boys and 19 girls), a Grade 6 Natural Sciences teacher who was my critical friend, and two expert community members. To generate data, I used a focus group discussion, group activities, classroom observations, and learners’ reflective journals. Vygotsky’s socio-cultural theory and Ogunniyi’s Contiguity Argumentation Theory (CAT) were used as theoretical and analytical frameworks, respectively. A thematic approach to data analysis was employed. That is, data were analysed inductively to identify sub-themes and subsequently similar sub-themes were grouped together to form themes. The two expert community members’ presentations equipped my learners with stories on cultural beliefs and practices that were used in the olden days (past) and how such stories are used in our days (present). For instance, the findings of this study revealed that women during menstruation must not drink amasi as it is believed that it would prolong the menstruation time. The findings also revealed that eating of amaqanda and inside meat by youths should be minimised as it is believed that it can stimulate their sex hormones. It also revealed that there is no relevance to science that men eating imifino would be weak among other men who do not eat them. The implications for this study is that science teachers should make some efforts to integrate IK in their teaching to make science accessible and relevant to their learners. To achieve this, the study thus recommends that science teachers should find ways of tapping into the cultural heritage and wisdom that is possessed by the expert community members to enable learners to cross the bridge from home to school. , Thesis (MEd) -- Faculty of Education, Education, 2021
- Full Text:
- Date Issued: 2021-10
Potential of the Gravel Filter Towers, Pilot-scale Filter system and Biochar/Clay adsorbents for Bio-Physicochemical remediation and Desalination of greywater
- Authors: Bani, Siphumze
- Date: 2021-10-29
- Subjects: Uncatalogued
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/188375 , vital:44748
- Description: Thesis embargoed until 2023 , Thesis (MSc) -- Faculty of Science, Rhodes University Biotechnology Innovation Centre, 2021
- Full Text:
- Date Issued: 2021-10-29
- Authors: Bani, Siphumze
- Date: 2021-10-29
- Subjects: Uncatalogued
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/188375 , vital:44748
- Description: Thesis embargoed until 2023 , Thesis (MSc) -- Faculty of Science, Rhodes University Biotechnology Innovation Centre, 2021
- Full Text:
- Date Issued: 2021-10-29
The synthesis and characterisation of Sn(IV) porphyrin derivatives and their potential application in anti-cancer and antimicrobial photodynamic therapy
- Authors: Dingiswayo, Somila
- Date: 2021-10
- Subjects: Porphyrins , Photochemotherapy , Cancer Photochemotherapy , Active oxygen Physiological effect , Aromaticity (Chemistry) , Tetrapyrroles , Magnetic circular dichroism , Corroles , Chlorins , Photodynamic antimicrobial chemotherapy (PACT)
- Language: English
- Type: Masters theses , text
- Identifier: http://hdl.handle.net/10962/188843 , vital:44791
- Description: In photodynamic therapy (PDT), the activation of light-sensitive drugs in tumour cells produces reactive singlet oxygen species, which cause tumour destruction through a cascade of biochemical reactions. Over the years, the wavelength of activation has been shown to be a critical factor in the penetration of light. Hence the properties of photosensitiser dyes in this context shape their ability to treat deep-seated tumours. In this study, the synthesis, structural characterisation and photophysicochemical properties of a series of Sn(IV) porphyrins with meso-methylthiophenyl rings that have been prepared to study their PDT and photodynamic antimicrobial chemotherapy (PACT) activity properties are reported. The series of Sn(IV) complexes is comprised of a porphyrin (1-Sn), a corrole (2-Sn), a chlorin (3-Sn) and an N-confused porphyrin (4-Sn). Herein, the low symmetry Sn(IV) porphyrin derivatives are shown to have excellent singlet oxygen generation capabilities, and lifetimes of the triplet excited states were in the microsecond range. For example, 4-Sn had a singlet oxygen quantum yield (ФΔ) and an excited triplet state lifetime (τT) of 0.88 and 27 μs, respectively. The complexes were studied using UV-visible and magnetic circular dichroism (MCD) spectroscopies. Interestingly, the positive-to-negative sign sequences of the Faraday B0 terms of 2-Sn and 3-Sn reveal that the structural modifications involved break the degeneracy of the MOs derived from the 1eg* LUMO of the porphyrin 1-Sn. In contrast, a conventional negative-to-positive sign sequence is observed for 4-Sn, since the confusion of a pyrrole moiety also results in a large separation of the 1a1u and 1a2u MOs of the porphyrin 1-Sn that are derived from the HOMO of a C16H162−parent hydrocarbon perimeter. The trends in the electronic structures of the Sn(IV) complexes were further investigated through a series of time-dependent density functional theory calculations, so that the suitability of the different types of complex for use in singlet oxygen applications could be further explored. During in vitro photodynamic antimicrobial chemotherapy (PACT) studies, chlorin derivative 3-Sn had the highest activity towards S. aureus and E. coli with log10 reductions of 10.5 and 8.74, respectively. The unusually high activity of 3-Sn against E.coli suggests that the interaction of neutral photosensitisers with gram-negativebacteria is more complex than previously understood. Anti-cancer PDT studies demonstrated that the photosensitisers had negligible dark cytotoxicity. Upon photoirradiation, the Sn(IV) complexes consistently exhibited IC50 values lower than 15 μM against MCF-7 adenocarcinoma cells. An IC50 value of 1.4 μM for 4-Sn after activation at the deep-red region of the spectrum demonstrates that complexes of this type merit further in-depth investigation. The results provide evidence that the low-symmetry Sn(IV) chlorins and N-confused porphyrins merit further in-depth study for use in singlet oxygen applications. , Thesis (MSc) -- Faculty of Science, Chemistry, 2021
- Full Text:
- Date Issued: 2021-10
- Authors: Dingiswayo, Somila
- Date: 2021-10
- Subjects: Porphyrins , Photochemotherapy , Cancer Photochemotherapy , Active oxygen Physiological effect , Aromaticity (Chemistry) , Tetrapyrroles , Magnetic circular dichroism , Corroles , Chlorins , Photodynamic antimicrobial chemotherapy (PACT)
- Language: English
- Type: Masters theses , text
- Identifier: http://hdl.handle.net/10962/188843 , vital:44791
- Description: In photodynamic therapy (PDT), the activation of light-sensitive drugs in tumour cells produces reactive singlet oxygen species, which cause tumour destruction through a cascade of biochemical reactions. Over the years, the wavelength of activation has been shown to be a critical factor in the penetration of light. Hence the properties of photosensitiser dyes in this context shape their ability to treat deep-seated tumours. In this study, the synthesis, structural characterisation and photophysicochemical properties of a series of Sn(IV) porphyrins with meso-methylthiophenyl rings that have been prepared to study their PDT and photodynamic antimicrobial chemotherapy (PACT) activity properties are reported. The series of Sn(IV) complexes is comprised of a porphyrin (1-Sn), a corrole (2-Sn), a chlorin (3-Sn) and an N-confused porphyrin (4-Sn). Herein, the low symmetry Sn(IV) porphyrin derivatives are shown to have excellent singlet oxygen generation capabilities, and lifetimes of the triplet excited states were in the microsecond range. For example, 4-Sn had a singlet oxygen quantum yield (ФΔ) and an excited triplet state lifetime (τT) of 0.88 and 27 μs, respectively. The complexes were studied using UV-visible and magnetic circular dichroism (MCD) spectroscopies. Interestingly, the positive-to-negative sign sequences of the Faraday B0 terms of 2-Sn and 3-Sn reveal that the structural modifications involved break the degeneracy of the MOs derived from the 1eg* LUMO of the porphyrin 1-Sn. In contrast, a conventional negative-to-positive sign sequence is observed for 4-Sn, since the confusion of a pyrrole moiety also results in a large separation of the 1a1u and 1a2u MOs of the porphyrin 1-Sn that are derived from the HOMO of a C16H162−parent hydrocarbon perimeter. The trends in the electronic structures of the Sn(IV) complexes were further investigated through a series of time-dependent density functional theory calculations, so that the suitability of the different types of complex for use in singlet oxygen applications could be further explored. During in vitro photodynamic antimicrobial chemotherapy (PACT) studies, chlorin derivative 3-Sn had the highest activity towards S. aureus and E. coli with log10 reductions of 10.5 and 8.74, respectively. The unusually high activity of 3-Sn against E.coli suggests that the interaction of neutral photosensitisers with gram-negativebacteria is more complex than previously understood. Anti-cancer PDT studies demonstrated that the photosensitisers had negligible dark cytotoxicity. Upon photoirradiation, the Sn(IV) complexes consistently exhibited IC50 values lower than 15 μM against MCF-7 adenocarcinoma cells. An IC50 value of 1.4 μM for 4-Sn after activation at the deep-red region of the spectrum demonstrates that complexes of this type merit further in-depth investigation. The results provide evidence that the low-symmetry Sn(IV) chlorins and N-confused porphyrins merit further in-depth study for use in singlet oxygen applications. , Thesis (MSc) -- Faculty of Science, Chemistry, 2021
- Full Text:
- Date Issued: 2021-10
Potential Synergism between Entomopathogenic Fungi and Entomopathogenic Nematodes for the control of false codling moth (Thaumatotibia leucotreta)
- Authors: Prinsloo, Samantha Lee
- Date: 2021-10
- Subjects: Cryptophlebia leucotreta , Entomopathogenic fungi , Insect nematodes , Citrus Diseases and pests , Cryptophlebia leucotreta Biological control , Pests Integrated control , Biological pest control agents
- Language: English
- Type: Masters theses , text
- Identifier: http://hdl.handle.net/10962/188832 , vital:44790
- Description: False codling moth, Thaumatotibia leucotreta (Meyrick) (Lepidoptera: Tortricidae) (FCM), is a major phytosanitary pest of citrus in South Africa. Sufficient control measures for the soil-dwelling life stages of FCM have yet to be identified and owing to restrictions on the use of insecticides, non-chemical control options have been investigated including the use of entomopathogenic fungi (EPF) and entomopathogenic nematodes (EPN). Laboratory and field trials on an indigenous EPF, Metarhizium anisopliae FCM Ar 23 B3, have shown that this isolate is capable of inducing mortality in FCM soil-dwelling life stages. Other agents that have been highlighted as potential controls for soil-dwelling FCM life stages are the EPN species Steinernema yirgalemense 157-C, S. jeffreyense J194 and H. noenieputensis 158-C. This study conducted laboratory bioassays to assess the virulence of these four control agents on fifth instar FCM, in 24-well plates. These results reaffirmed the virulence of the four microbial control agents at their recommended doses of 50 IJs (EPN) and 1×107 conidia/ml (EPF) against fifth instar FCM with 80 to 96% larval mortality recorded. The EPF isolate exhibited the lowest mortality whilst S. yirgalemense induced the greatest mortality. In addition, the lethal concentration (LC) values for each isolate were determined using dose response bioassays. These values were previously unknown for all EPN species and for the EPF isolate based on the methodology used in this study. The LC50 results in order from lowest to highest EPN IJ concentration requirements were 4.38 IJs (S. yirgalemense), 4.47 IJs (S. jeffreyense) and 7.11 IJs (H. noenieputensis). The EPF isolate exhibited an LC50 of 3.42×105 conidia/ml. Lastly, research has shown that the combination of two control agents may increase control of late instar lepidopteran and coleopteran larvae, through synergistic interactions. Thus, the interactions that occurred between the combination of these EPN species with the EPF isolate were determined. This study found that when all three EPN species were combined simultaneously and sequentially with the EPF isolate M. anisopliae FCM AR 23 B3, additive interactions took place with exception of the simultaneous application of S. yirgalemense and H. noenieputensis, with the EPF and S. jeffreyense applied 24 h post EPF application. For the former, a synergistic interaction was found, whilst for the latter two, an antagonistic interaction. Although no strongly synergistic interactions were observed, additive interactions have been shown to reach a synergistic level when certain parameters are changed. Moving forward, a uniform methodology for conducting EPF/EPN interaction experiments has been suggested. It has also been recommended that due to the additive interactions observed in this study, laboratory soil-bioassays and field trials should be carried out for all three EPN species in combination with the EPF isolate. This research will inevitably facilitate the constant knowledge into management strategies for the phytosanitary pest, FCM in South African citrus. , Thesis (MSc) -- Science, Zoology and Entomology, 2021
- Full Text:
- Date Issued: 2021-10
- Authors: Prinsloo, Samantha Lee
- Date: 2021-10
- Subjects: Cryptophlebia leucotreta , Entomopathogenic fungi , Insect nematodes , Citrus Diseases and pests , Cryptophlebia leucotreta Biological control , Pests Integrated control , Biological pest control agents
- Language: English
- Type: Masters theses , text
- Identifier: http://hdl.handle.net/10962/188832 , vital:44790
- Description: False codling moth, Thaumatotibia leucotreta (Meyrick) (Lepidoptera: Tortricidae) (FCM), is a major phytosanitary pest of citrus in South Africa. Sufficient control measures for the soil-dwelling life stages of FCM have yet to be identified and owing to restrictions on the use of insecticides, non-chemical control options have been investigated including the use of entomopathogenic fungi (EPF) and entomopathogenic nematodes (EPN). Laboratory and field trials on an indigenous EPF, Metarhizium anisopliae FCM Ar 23 B3, have shown that this isolate is capable of inducing mortality in FCM soil-dwelling life stages. Other agents that have been highlighted as potential controls for soil-dwelling FCM life stages are the EPN species Steinernema yirgalemense 157-C, S. jeffreyense J194 and H. noenieputensis 158-C. This study conducted laboratory bioassays to assess the virulence of these four control agents on fifth instar FCM, in 24-well plates. These results reaffirmed the virulence of the four microbial control agents at their recommended doses of 50 IJs (EPN) and 1×107 conidia/ml (EPF) against fifth instar FCM with 80 to 96% larval mortality recorded. The EPF isolate exhibited the lowest mortality whilst S. yirgalemense induced the greatest mortality. In addition, the lethal concentration (LC) values for each isolate were determined using dose response bioassays. These values were previously unknown for all EPN species and for the EPF isolate based on the methodology used in this study. The LC50 results in order from lowest to highest EPN IJ concentration requirements were 4.38 IJs (S. yirgalemense), 4.47 IJs (S. jeffreyense) and 7.11 IJs (H. noenieputensis). The EPF isolate exhibited an LC50 of 3.42×105 conidia/ml. Lastly, research has shown that the combination of two control agents may increase control of late instar lepidopteran and coleopteran larvae, through synergistic interactions. Thus, the interactions that occurred between the combination of these EPN species with the EPF isolate were determined. This study found that when all three EPN species were combined simultaneously and sequentially with the EPF isolate M. anisopliae FCM AR 23 B3, additive interactions took place with exception of the simultaneous application of S. yirgalemense and H. noenieputensis, with the EPF and S. jeffreyense applied 24 h post EPF application. For the former, a synergistic interaction was found, whilst for the latter two, an antagonistic interaction. Although no strongly synergistic interactions were observed, additive interactions have been shown to reach a synergistic level when certain parameters are changed. Moving forward, a uniform methodology for conducting EPF/EPN interaction experiments has been suggested. It has also been recommended that due to the additive interactions observed in this study, laboratory soil-bioassays and field trials should be carried out for all three EPN species in combination with the EPF isolate. This research will inevitably facilitate the constant knowledge into management strategies for the phytosanitary pest, FCM in South African citrus. , Thesis (MSc) -- Science, Zoology and Entomology, 2021
- Full Text:
- Date Issued: 2021-10
Scaffolding argumentative writing through Reading to Learn (RtL) pedagogy: a case study of three grade 11 English second language teachers in Namibia
- Authors: Matengu, Ernest Samubu
- Date: 2021-10
- Subjects: Rose, David, 1955- , Reading (Secondary) , Persuasion (Rhetoric) Study and teaching (Secondary) Namibia , English language Writing Study and teaching (Secondary) Namibia , English language Rhetoric Study and teaching (Secondary) Namibia , English language Study and teaching (Secondary) Foreign speakers Case studies , Reading to Learn , Scaffolding Interaction Cycle
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/191148 , vital:45065
- Description: The central aim of this study was to investigate the positive impact of Reading to Learn (RtL) pedagogy in enhancing Grade 11 learners’ argumentative writing skills. This was a case study of one school in Otjozondjupa region in Namibia. The pedagogy, RtL, was designed to address learning inequalities with marginalised communities in Australia. Coupled with challenges in literacy development in learners, current methods have not successfully addressed the teaching and learning of argumentative writing amidst learning inequalities. This study employed the six stages of Scaffolding Interaction Cycle of RtL in order to teach argumentative writing. As is evidenced in recent research, the scaffolding cycle of RtL provides equal opportunities to learners from diverse backgrounds to attain epistemological access at the same pace. RtL’s theoretical and conceptual framework is derived from Bernstein’s theory of education as pedagogic discourse (a device for maintaining inequality in society), Vygotsky’s theory of learning as a social process and Halliday’s model of language as text in social context. The two research questions for this study were: (1) What role does Reading to Learn (RtL) pedagogy play in developing Grade 11 learners’ ability to write argumentative essays? And (2) How can the implementation of RtL pedagogy through scaffolding impact on/improve learners’ literacy skills development for argumentative essay writing? This qualitative case study generated data through observation of three teachers’ lessons, a Stimulated Recall Interview (SRI) conducted with the three teachers and learners’ pre and posttest of argumentative essays. The findings of this study revealed that teachers found RtL as a comprehensive pedagogy that makes teaching and learning of argumentative writing successful through systematic scaffolding of learning. Learners’ written pre and posttest also showed a narrowing of the gap between weak and strong learners in that weak learners recorded an upward trend similar to that of strong learners in their posttest. Given the design of RtL and studies conducted globally, the findings of this study can be comparable. , Thesis (MEd) -- Faculty of Education, Education, 2021
- Full Text:
- Date Issued: 2021-10
- Authors: Matengu, Ernest Samubu
- Date: 2021-10
- Subjects: Rose, David, 1955- , Reading (Secondary) , Persuasion (Rhetoric) Study and teaching (Secondary) Namibia , English language Writing Study and teaching (Secondary) Namibia , English language Rhetoric Study and teaching (Secondary) Namibia , English language Study and teaching (Secondary) Foreign speakers Case studies , Reading to Learn , Scaffolding Interaction Cycle
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/191148 , vital:45065
- Description: The central aim of this study was to investigate the positive impact of Reading to Learn (RtL) pedagogy in enhancing Grade 11 learners’ argumentative writing skills. This was a case study of one school in Otjozondjupa region in Namibia. The pedagogy, RtL, was designed to address learning inequalities with marginalised communities in Australia. Coupled with challenges in literacy development in learners, current methods have not successfully addressed the teaching and learning of argumentative writing amidst learning inequalities. This study employed the six stages of Scaffolding Interaction Cycle of RtL in order to teach argumentative writing. As is evidenced in recent research, the scaffolding cycle of RtL provides equal opportunities to learners from diverse backgrounds to attain epistemological access at the same pace. RtL’s theoretical and conceptual framework is derived from Bernstein’s theory of education as pedagogic discourse (a device for maintaining inequality in society), Vygotsky’s theory of learning as a social process and Halliday’s model of language as text in social context. The two research questions for this study were: (1) What role does Reading to Learn (RtL) pedagogy play in developing Grade 11 learners’ ability to write argumentative essays? And (2) How can the implementation of RtL pedagogy through scaffolding impact on/improve learners’ literacy skills development for argumentative essay writing? This qualitative case study generated data through observation of three teachers’ lessons, a Stimulated Recall Interview (SRI) conducted with the three teachers and learners’ pre and posttest of argumentative essays. The findings of this study revealed that teachers found RtL as a comprehensive pedagogy that makes teaching and learning of argumentative writing successful through systematic scaffolding of learning. Learners’ written pre and posttest also showed a narrowing of the gap between weak and strong learners in that weak learners recorded an upward trend similar to that of strong learners in their posttest. Given the design of RtL and studies conducted globally, the findings of this study can be comparable. , Thesis (MEd) -- Faculty of Education, Education, 2021
- Full Text:
- Date Issued: 2021-10
Exploring affordances and hindrances when using Grade 8 Physical Science learners’ home language to mediate learning of chemical bonding
- Shilongo, Wilhelm Nghidiputate
- Authors: Shilongo, Wilhelm Nghidiputate
- Date: 2021-10
- Subjects: Science Study and teaching (Secondary) Namibia , Code switching (Linguistics) , Chemical bonds , Education, Bilingual Namibia , Native language and education Namibia , Socio-cultural theory
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/191079 , vital:45056
- Description: It seems code-switching from English to learners’ home language is a regular practice in Namibian schools. That is, science teachers mediate specific challenging science topics such as chemical bonding through code-switching from English to learners’ home languages. Based on anecdotal evidence and on Grade 10 Examiners’ Reports for previous years, chemical bonding is one of the challenging key concepts in Physical Science, and yet it is an important concept in the study of chemistry. Therefore, the purpose of this interventionist study was to investigate how the use of learners’ home language enables and/or constrains Grade 8 Physical Science learners’ sense making of the topic, chemical bonding. The study is a convergent parallel mixed method case study and was underpinned by an interpretive paradigm. It was conducted with 17 Grade 8 learners in a rural school, where I teach, in the Oshana region. I used a diagnostic test to elicit learners’ prior knowledge on this topic, a post-intervention test, observation, reflections, focus group interview and stimulated recall interviews as my data collection methods. I used Vygotsky’s (1978) Socio-Cultural Theory as my theoretical framework to help explain how learners make sense of the concept of chemical bonding when learners’ home language is used in a Physical Science class. To analyse the quantitative data obtained, I used a descriptive statistics and inferential statistics method. In the descriptive statistics, data were compiled into graphs, tables, and other visual representations, while for the inferential statistics, a t-test was used to establish the significant difference of the data collected. On the other hand, a thematic approach to analyse the qualitative data was employed to come up with sub-themes and themes. The findings of the study revealed that learners’ home language stimulates learners’ interest to learn new concepts, and enhances learners’ understanding and participation during the science lessons. Another finding of the study revealed that learners’ prior knowledge in chemical bonding contained some misconceptions. Furthermore, the findings of the study also revealed that learners learn best when their prior knowledge are elicited before they are introduced to new concepts in their science classrooms. The study recommends that learners’ home language should be incorporated into Physical Science lessons, especially when the teachers are teaching challenging concepts such as chemical bonding. , Thesis (MEd) -- Faculty of Education, Education, 2021
- Full Text:
- Date Issued: 2021-10
- Authors: Shilongo, Wilhelm Nghidiputate
- Date: 2021-10
- Subjects: Science Study and teaching (Secondary) Namibia , Code switching (Linguistics) , Chemical bonds , Education, Bilingual Namibia , Native language and education Namibia , Socio-cultural theory
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/191079 , vital:45056
- Description: It seems code-switching from English to learners’ home language is a regular practice in Namibian schools. That is, science teachers mediate specific challenging science topics such as chemical bonding through code-switching from English to learners’ home languages. Based on anecdotal evidence and on Grade 10 Examiners’ Reports for previous years, chemical bonding is one of the challenging key concepts in Physical Science, and yet it is an important concept in the study of chemistry. Therefore, the purpose of this interventionist study was to investigate how the use of learners’ home language enables and/or constrains Grade 8 Physical Science learners’ sense making of the topic, chemical bonding. The study is a convergent parallel mixed method case study and was underpinned by an interpretive paradigm. It was conducted with 17 Grade 8 learners in a rural school, where I teach, in the Oshana region. I used a diagnostic test to elicit learners’ prior knowledge on this topic, a post-intervention test, observation, reflections, focus group interview and stimulated recall interviews as my data collection methods. I used Vygotsky’s (1978) Socio-Cultural Theory as my theoretical framework to help explain how learners make sense of the concept of chemical bonding when learners’ home language is used in a Physical Science class. To analyse the quantitative data obtained, I used a descriptive statistics and inferential statistics method. In the descriptive statistics, data were compiled into graphs, tables, and other visual representations, while for the inferential statistics, a t-test was used to establish the significant difference of the data collected. On the other hand, a thematic approach to analyse the qualitative data was employed to come up with sub-themes and themes. The findings of the study revealed that learners’ home language stimulates learners’ interest to learn new concepts, and enhances learners’ understanding and participation during the science lessons. Another finding of the study revealed that learners’ prior knowledge in chemical bonding contained some misconceptions. Furthermore, the findings of the study also revealed that learners learn best when their prior knowledge are elicited before they are introduced to new concepts in their science classrooms. The study recommends that learners’ home language should be incorporated into Physical Science lessons, especially when the teachers are teaching challenging concepts such as chemical bonding. , Thesis (MEd) -- Faculty of Education, Education, 2021
- Full Text:
- Date Issued: 2021-10
Management approach of patients with violent and aggressive behaviour in a district hospital setting in South Africa
- Adeniyi, Oladele Vincent, Puzi, Ntandazo
- Authors: Adeniyi, Oladele Vincent , Puzi, Ntandazo
- Date: 2021
- Subjects: mental health Emergency medical services violennce Article
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/11260/7284 , vital:53108 , xlink:href="https://doi.org/10.4102/safp.v63i1.5393"
- Description: Background: Given the physical and mental health consequences of tobacco use amongst individuals with mental illness, it was imperative to assess the burden of tobacco use in this population. Aim: This study examined the patterns and factors associated with tobacco use in individuals attending the outpatient unit. Setting: Cecilia Makiwane Hospital Mental Health Department in Eastern Cape province, South Africa. Methods: Lifetime (ever use) use and current use of any tobacco products were examined in a cross-sectional study of 390 individuals between March and June 2020. A logistic regression was fitted to determine the correlates of lifetime and current use of any tobacco products. Results: The rates of ever use and current use of tobacco products were 59.4% and 44.6%, respectively. Of the participants interviewed, lifetime tobacco use was more prevalent amongst individuals with schizophrenia (67.9%) and cannabis-induced disorders (97.3%) and lower in those with major depressive disorders (36.1%) and bipolar and related disorders (43.5%). Men were six times more likely to have ever used or currently use tobacco products in comparison to women. Also, those who had a salaried job or owned a business were over three times more likely to have ever used or currently use tobacco products compared with those receiving government social grants. Conclusions: The prevalence of tobacco use in this study was significantly higher than the general population in the Eastern Cape. Therefore, smoking prevention and cessation interventions targeted at the general population should target this often neglected sub-population in the region. Keywords: aggressive and violent behaviour; assisted user; emergency centres; involuntary user; Mental Health Care Act.
- Full Text:
- Date Issued: 2021
- Authors: Adeniyi, Oladele Vincent , Puzi, Ntandazo
- Date: 2021
- Subjects: mental health Emergency medical services violennce Article
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/11260/7284 , vital:53108 , xlink:href="https://doi.org/10.4102/safp.v63i1.5393"
- Description: Background: Given the physical and mental health consequences of tobacco use amongst individuals with mental illness, it was imperative to assess the burden of tobacco use in this population. Aim: This study examined the patterns and factors associated with tobacco use in individuals attending the outpatient unit. Setting: Cecilia Makiwane Hospital Mental Health Department in Eastern Cape province, South Africa. Methods: Lifetime (ever use) use and current use of any tobacco products were examined in a cross-sectional study of 390 individuals between March and June 2020. A logistic regression was fitted to determine the correlates of lifetime and current use of any tobacco products. Results: The rates of ever use and current use of tobacco products were 59.4% and 44.6%, respectively. Of the participants interviewed, lifetime tobacco use was more prevalent amongst individuals with schizophrenia (67.9%) and cannabis-induced disorders (97.3%) and lower in those with major depressive disorders (36.1%) and bipolar and related disorders (43.5%). Men were six times more likely to have ever used or currently use tobacco products in comparison to women. Also, those who had a salaried job or owned a business were over three times more likely to have ever used or currently use tobacco products compared with those receiving government social grants. Conclusions: The prevalence of tobacco use in this study was significantly higher than the general population in the Eastern Cape. Therefore, smoking prevention and cessation interventions targeted at the general population should target this often neglected sub-population in the region. Keywords: aggressive and violent behaviour; assisted user; emergency centres; involuntary user; Mental Health Care Act.
- Full Text:
- Date Issued: 2021
Is there an inverse-u relationship between financialisation and investment?: South Africa’s stock market capitalisation in comparative perspective
- Authors: Owen, Michael Robert
- Date: 2021-10
- Subjects: Monetary policy South Africa , Globalization , Economics South Africa , Capital movements South Africa , Stock exchanges South Africa , Investments South Africa , Economic development South Africa , South Africa Economic conditions 1991-
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/191084 , vital:45058
- Description: In recent decades, the growth and fluctuations in the financial sector have become increasingly disjointed from events in the real economy. There has been a dramatic increase in global market integration and globalisation since the 2008 financial crisis. The argument presented in the thesis shows perspective from the two general debates in Economics. The Orthodox view, which suggests there is an efficient flow of resources between people and institutions over time, supports the argument that there is a positive relationship between financialisation and economic growth. Alternatively, the Heterodox view argues that financial liberalisation fails to anticipate market effects and requires intervention in order to limit negative consequences. More recent studies have proposed an inverse-U theory between financialisation and investment, which suggests that there is a threshold, above which further financial development and financial globalisation has detrimental effects on the real economy. With South Africa being a developing country that is highly reliant on capital inflows to finance the economy, there is space for more acute research to investigate whether South Africa has surpassed this threshold. This study focusses on one aspect of this relationship, namely the relationship between Stock Market Capitalisation and Investment. It uses panel data analysis and other methods to explore whether such an inverse-U relationship exists internationally, and whether South Africa is suffering from the effects of financialisation. , Thesis (MCom) -- Faculty of Commerce, Economics and Economic History, 2021
- Full Text:
- Date Issued: 2021-10
- Authors: Owen, Michael Robert
- Date: 2021-10
- Subjects: Monetary policy South Africa , Globalization , Economics South Africa , Capital movements South Africa , Stock exchanges South Africa , Investments South Africa , Economic development South Africa , South Africa Economic conditions 1991-
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/191084 , vital:45058
- Description: In recent decades, the growth and fluctuations in the financial sector have become increasingly disjointed from events in the real economy. There has been a dramatic increase in global market integration and globalisation since the 2008 financial crisis. The argument presented in the thesis shows perspective from the two general debates in Economics. The Orthodox view, which suggests there is an efficient flow of resources between people and institutions over time, supports the argument that there is a positive relationship between financialisation and economic growth. Alternatively, the Heterodox view argues that financial liberalisation fails to anticipate market effects and requires intervention in order to limit negative consequences. More recent studies have proposed an inverse-U theory between financialisation and investment, which suggests that there is a threshold, above which further financial development and financial globalisation has detrimental effects on the real economy. With South Africa being a developing country that is highly reliant on capital inflows to finance the economy, there is space for more acute research to investigate whether South Africa has surpassed this threshold. This study focusses on one aspect of this relationship, namely the relationship between Stock Market Capitalisation and Investment. It uses panel data analysis and other methods to explore whether such an inverse-U relationship exists internationally, and whether South Africa is suffering from the effects of financialisation. , Thesis (MCom) -- Faculty of Commerce, Economics and Economic History, 2021
- Full Text:
- Date Issued: 2021-10
A case study of lessons learned through empowering and mobilizing unemployed youth into sustainable green jobs within the SANBI – Groen Sebenza partnership programme by a Host Institution in South Africa
- Authors: Fullard, Donovan
- Date: 2021-10-29
- Subjects: South African National Biodiversity Institute , Green movement South Africa , Environmental education South Africa , Communities of practice South Africa , Social learning South Africa , Biodiversity conservation Employees , Job creation South Africa , Mentoring South Africa , Groen Sebenza
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/191964 , vital:45183
- Description: This research project constituted as a thesis of limited scope for a Masters in Education Degree (i.e. as 50% of the degree) focusses on a job creation programme named ‘Groen Sebenza’ [Green Work]. Groen Sebenza is an environmental education ‘incubator’ programme driven and implemented by the South African National Biodiversity Institute (SANBI) to unlock green jobs and bridge the gap between education and job opportunities in the biodiversity sector in South Africa. The programme is a key intervention to strengthen biodiversity human capacity development in the biodiversity sector in South Africa, seeking to contribute to transformation of the biodiversity sector, and also address issues of youth unemployment in the country. The young ‘interns’ in the programme were called ‘pioneers’ at the start of the project. This research project explores how a host institution operating as a community of practice within a landscape of practice managed to implement the Groen Sebenza programme by absorbing and appointing all their pioneers into sustainable jobs beyond the pilot project. I sought to better understand the process of supporting and empowering unemployed youth into sustainable green jobs within the Groen Sebenza partnership programme. I drew on Community of Practice (CoP) theory, and its value creation framework to develop this understanding, and I under-laboured the analysis with a social realist analysis of enabling and constraining factors. The unit of analysis of a Community of Practice was a useful focus for the study, as these mentors, managers, and administrators were all involved in supporting the empowerment and retention of the young pioneers in the host institution. To develop deeper insight into the learning and knowing, and value created in and by the Groen Sebenza CoP in the Host Institution, I also sought insight into enabling and constraining factors and how these shaped and contributed to empowerment and retention of the pioneers in sustainable green jobs. The research addressed the main question of ‘How do processes of learning, knowing and value creation contribute to empowerment and retention of unemployed youth in a successful Host Institution in the Groen Sebenza programme, and what enabled or constrained the empowerment and retention processes and outcomes?’. Three sub-questions were used in the study, which focussed on the mentoring, training and workplace experiences and how they contribute to the process of learning and knowing within the Groen Sebenza Community of Practice in the Host Institution? [Addressed in Chapter 4], the value creation elements that emerged in the implementation of the programme in support and empowerment of the pioneers in the Host institution’s Groen Sebenza CoP? [Addressed in Chapter 5], and the enabling and constraining factors that shaped and contributed to the uptake of the Pioneers into sustainable green jobs at the Host Institution within the Groen Sebenza Programme? [Addressed in Chapter 6]. The research was conducted as a qualitative case study, in which I used semi-structured interviews as a key data source, as well as document analysis, and a questionnaire. The study drew on inductive, abductive and retroductive modes of inference since I sought to explore an understanding of the practices and learning that occurred that contributed and led to the successful uptake of Pioneers into jobs, as well as the enabling and constraining factors. The study was interpretive at the epistemic level, and had a social realist under-labouring at the ontological level. Key findings of the study point to the development of enabling cultures of mentoring in workplaces, and the provision of a diversity of workplace learning experiences including formal training. It also points to the importance of personal emergent properties amongst mentors and pioneers that embrace a willingness to work together and build strong relationships, and to learn together. Learning in the community of practice was shown to develop identity and a sense of belonging as pioneers were given meaningful tasks to do and their training and interactions with mentors was experienced as meaningful and relevant. The contributions of the pioneers to the institutional mandate was appreciated by the mentors and therefore also well supported within an empowerment orientation. Various structural factors contributed to this enabling situation, most notably strong support from management as well as good co-operation across divisions. Constraining factors included the physical distances in the province, as well as financial and technical issues such as poor ICT communication systems. Overall, though the study showed that a strong approach to learning in communities of practice supported by empowering mentoring can lead to the integration of young pioneers into sustainable green jobs in the environmental sector. A whole institution approach to this process is, however, needed, and the organisation needs to develop a culture of social learning. As recently as September 2020 as this study was being finalised, the Presidential Employment Stimulus Plan (Office of the President, 2020) following the initial economic shocks emanating from the COVID-19 pandemic, made yet another commitment to using the Groen Sebenza model to create and support sustainable job creation for young people in South Africa today in the environmental sector. This study has been developed and designed to understand those processes and enabling conditions that can support retention and empowerment of young people to take up jobs in the environmental sector today. Its recommendations may therefore be of value to those involved in seeking to support sustainable impacts in terms of retention and employment in programmes such as the Groen Sebenza, and in the Groen Sebenza programme itself as it continues to unfold as a key job creation tool for unemployed youth. , Thesis (MEd) -- Faculty of Education, Education, 2021
- Full Text:
- Date Issued: 2021-10-29
- Authors: Fullard, Donovan
- Date: 2021-10-29
- Subjects: South African National Biodiversity Institute , Green movement South Africa , Environmental education South Africa , Communities of practice South Africa , Social learning South Africa , Biodiversity conservation Employees , Job creation South Africa , Mentoring South Africa , Groen Sebenza
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/191964 , vital:45183
- Description: This research project constituted as a thesis of limited scope for a Masters in Education Degree (i.e. as 50% of the degree) focusses on a job creation programme named ‘Groen Sebenza’ [Green Work]. Groen Sebenza is an environmental education ‘incubator’ programme driven and implemented by the South African National Biodiversity Institute (SANBI) to unlock green jobs and bridge the gap between education and job opportunities in the biodiversity sector in South Africa. The programme is a key intervention to strengthen biodiversity human capacity development in the biodiversity sector in South Africa, seeking to contribute to transformation of the biodiversity sector, and also address issues of youth unemployment in the country. The young ‘interns’ in the programme were called ‘pioneers’ at the start of the project. This research project explores how a host institution operating as a community of practice within a landscape of practice managed to implement the Groen Sebenza programme by absorbing and appointing all their pioneers into sustainable jobs beyond the pilot project. I sought to better understand the process of supporting and empowering unemployed youth into sustainable green jobs within the Groen Sebenza partnership programme. I drew on Community of Practice (CoP) theory, and its value creation framework to develop this understanding, and I under-laboured the analysis with a social realist analysis of enabling and constraining factors. The unit of analysis of a Community of Practice was a useful focus for the study, as these mentors, managers, and administrators were all involved in supporting the empowerment and retention of the young pioneers in the host institution. To develop deeper insight into the learning and knowing, and value created in and by the Groen Sebenza CoP in the Host Institution, I also sought insight into enabling and constraining factors and how these shaped and contributed to empowerment and retention of the pioneers in sustainable green jobs. The research addressed the main question of ‘How do processes of learning, knowing and value creation contribute to empowerment and retention of unemployed youth in a successful Host Institution in the Groen Sebenza programme, and what enabled or constrained the empowerment and retention processes and outcomes?’. Three sub-questions were used in the study, which focussed on the mentoring, training and workplace experiences and how they contribute to the process of learning and knowing within the Groen Sebenza Community of Practice in the Host Institution? [Addressed in Chapter 4], the value creation elements that emerged in the implementation of the programme in support and empowerment of the pioneers in the Host institution’s Groen Sebenza CoP? [Addressed in Chapter 5], and the enabling and constraining factors that shaped and contributed to the uptake of the Pioneers into sustainable green jobs at the Host Institution within the Groen Sebenza Programme? [Addressed in Chapter 6]. The research was conducted as a qualitative case study, in which I used semi-structured interviews as a key data source, as well as document analysis, and a questionnaire. The study drew on inductive, abductive and retroductive modes of inference since I sought to explore an understanding of the practices and learning that occurred that contributed and led to the successful uptake of Pioneers into jobs, as well as the enabling and constraining factors. The study was interpretive at the epistemic level, and had a social realist under-labouring at the ontological level. Key findings of the study point to the development of enabling cultures of mentoring in workplaces, and the provision of a diversity of workplace learning experiences including formal training. It also points to the importance of personal emergent properties amongst mentors and pioneers that embrace a willingness to work together and build strong relationships, and to learn together. Learning in the community of practice was shown to develop identity and a sense of belonging as pioneers were given meaningful tasks to do and their training and interactions with mentors was experienced as meaningful and relevant. The contributions of the pioneers to the institutional mandate was appreciated by the mentors and therefore also well supported within an empowerment orientation. Various structural factors contributed to this enabling situation, most notably strong support from management as well as good co-operation across divisions. Constraining factors included the physical distances in the province, as well as financial and technical issues such as poor ICT communication systems. Overall, though the study showed that a strong approach to learning in communities of practice supported by empowering mentoring can lead to the integration of young pioneers into sustainable green jobs in the environmental sector. A whole institution approach to this process is, however, needed, and the organisation needs to develop a culture of social learning. As recently as September 2020 as this study was being finalised, the Presidential Employment Stimulus Plan (Office of the President, 2020) following the initial economic shocks emanating from the COVID-19 pandemic, made yet another commitment to using the Groen Sebenza model to create and support sustainable job creation for young people in South Africa today in the environmental sector. This study has been developed and designed to understand those processes and enabling conditions that can support retention and empowerment of young people to take up jobs in the environmental sector today. Its recommendations may therefore be of value to those involved in seeking to support sustainable impacts in terms of retention and employment in programmes such as the Groen Sebenza, and in the Groen Sebenza programme itself as it continues to unfold as a key job creation tool for unemployed youth. , Thesis (MEd) -- Faculty of Education, Education, 2021
- Full Text:
- Date Issued: 2021-10-29
Coaches perspective on the positional demands of school boy (u18/u19) rugby players during a 70-minute match
- Authors: Barnard, Devon Vernon
- Date: 2021-10
- Subjects: Rugby football coaches South Africa , Rugby Union football players South Africa , Rugby football injuries South Africa , School sports South Africa , School sports Coaching South Africa , School sports Physiological aspects
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/190089 , vital:44962
- Description: INTRODUCTION: Rugby union has been one of the team sports that has grown over the last few years, and the margin between success and failure for teams has become narrower as the years have gone by. The game consists of players going through different movements such as sprints and/or collisions, that vary in intensity. The demands that face schoolboy rugby players are not well understood, and the lack of research in this area leads to a potential lack of understanding of the perceptions that coaches have about the demands that schoolboys are faced with during a match. OBJECTIVE: Therefore, the purpose of this study was to determine the perceptions that the schoolboy rugby coaches had surrounding the demands that their players are faced with during a 70-minute match. There were a few secondary purposes of the study, such as determining which school, government or private, had a better understanding or perception of the demands, as well as comparing strength and conditioning coaches’ perceptions to regular coaches’ perceptions. METHODS: This was a cross-sectional, descriptive study to determine the coach’s perceptions. These perceptions were collected through an online questionnaire, which consisted of ten sections and 74 questions. The questionnaire was piloted on a subject group with different types of experience. Coaches from the top 100 schools list were contacted through their school website. RESULTS: The questionnaire had a 72% response rate: 41 responses from 51 emails. The 41 responses consisted of 23 government schools and 18 private schools, which included 11 of the top 20 rugby schools in South Africa, with most responses coming from the Eastern Cape (41.5%). Results indicated that a government school’s coaches had significantly (p<0.05) more experience than private schools’ coaches, and that they had significantly (p<0.05) better academic qualifications than private schools. However, strength and conditioning coaches had significantly (p<0.01) better academic qualifications than coach, whereas coaches had significantly (p<0.01) better coaching qualifications than strength and conditioning coaches. CONCLUSION: “Experience has been shown to be a potential reason for what is described as a good coach”. This is also another potential reason why government schools are a dominant force in schoolboy rugby in South Africa. However, this is also coupled with better qualifications showing the dual importance of both experience and education. This study has shown that coaches, within a South African cohort, overall had good general perception of the demands of school level rugby matches. , Thesis (MSc) -- Faculty of Science, Human Kinetics and Ergonomics, 2021
- Full Text:
- Date Issued: 2021-10
- Authors: Barnard, Devon Vernon
- Date: 2021-10
- Subjects: Rugby football coaches South Africa , Rugby Union football players South Africa , Rugby football injuries South Africa , School sports South Africa , School sports Coaching South Africa , School sports Physiological aspects
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/190089 , vital:44962
- Description: INTRODUCTION: Rugby union has been one of the team sports that has grown over the last few years, and the margin between success and failure for teams has become narrower as the years have gone by. The game consists of players going through different movements such as sprints and/or collisions, that vary in intensity. The demands that face schoolboy rugby players are not well understood, and the lack of research in this area leads to a potential lack of understanding of the perceptions that coaches have about the demands that schoolboys are faced with during a match. OBJECTIVE: Therefore, the purpose of this study was to determine the perceptions that the schoolboy rugby coaches had surrounding the demands that their players are faced with during a 70-minute match. There were a few secondary purposes of the study, such as determining which school, government or private, had a better understanding or perception of the demands, as well as comparing strength and conditioning coaches’ perceptions to regular coaches’ perceptions. METHODS: This was a cross-sectional, descriptive study to determine the coach’s perceptions. These perceptions were collected through an online questionnaire, which consisted of ten sections and 74 questions. The questionnaire was piloted on a subject group with different types of experience. Coaches from the top 100 schools list were contacted through their school website. RESULTS: The questionnaire had a 72% response rate: 41 responses from 51 emails. The 41 responses consisted of 23 government schools and 18 private schools, which included 11 of the top 20 rugby schools in South Africa, with most responses coming from the Eastern Cape (41.5%). Results indicated that a government school’s coaches had significantly (p<0.05) more experience than private schools’ coaches, and that they had significantly (p<0.05) better academic qualifications than private schools. However, strength and conditioning coaches had significantly (p<0.01) better academic qualifications than coach, whereas coaches had significantly (p<0.01) better coaching qualifications than strength and conditioning coaches. CONCLUSION: “Experience has been shown to be a potential reason for what is described as a good coach”. This is also another potential reason why government schools are a dominant force in schoolboy rugby in South Africa. However, this is also coupled with better qualifications showing the dual importance of both experience and education. This study has shown that coaches, within a South African cohort, overall had good general perception of the demands of school level rugby matches. , Thesis (MSc) -- Faculty of Science, Human Kinetics and Ergonomics, 2021
- Full Text:
- Date Issued: 2021-10
Stable Covalent pH-Sensitive Metallophthalocyanines Thin Monolayer Films for Selective Detection of Neurotransmitters
- Idowu, Abosede Omowumi Atinuke
- Authors: Idowu, Abosede Omowumi Atinuke
- Date: 2021-10-29
- Subjects: Uncatalogued
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/192922 , vital:45279
- Description: Thesis (PhD) -- Faculty of Humanities, Science, Chemistry, 2021
- Full Text:
- Date Issued: 2021-10-29
- Authors: Idowu, Abosede Omowumi Atinuke
- Date: 2021-10-29
- Subjects: Uncatalogued
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/192922 , vital:45279
- Description: Thesis (PhD) -- Faculty of Humanities, Science, Chemistry, 2021
- Full Text:
- Date Issued: 2021-10-29
Echogenic liposomes for ultrasound-triggered drug delivery
- Authors: Izuchukwu, Ezekiel Charles
- Date: 2021-10
- Subjects: Liposomes , Drug delivery systems , Colon (Anatomy) Cancer Treatment , Transmission electron microscopy , Fourier transform infrared spectroscopy , Liquid chromatography , Echogenic liposomes , Ultrasound-triggered drug delivery
- Language: English
- Type: Masters theses , text
- Identifier: http://hdl.handle.net/10962/188997 , vital:44805
- Description: Colorectal cancer is one of common cancers worldwide. It is the third most diagnosed cancer and the second leading cause of death. The use of 5-fluorouracil (5-FU) alone or in a chemotherapy regime has been the effective treatment of colorectal cancer patients. The efficacy of 5-FU in colorectal cancer treatment is significantly limited by drug resistance, gastrointestinal, and bone marrow toxicity through high-level expression of thymidylate synthase, justifying a need to improve its therapeutic index. Liposomes are colloidal membranes comprising of one or more lipid bilayers enclosing an aqueous core. They have been used to improve the therapeutic index of many anti-cancer drugs by changing drug absorption, elongating biological half-life, reducing metabolism, and reducing toxicity to healthy tissues. Echogenic liposomes are specifically designed to respond to external triggering like ultrasound stimulation by entrapping a gas or an emulsion that can vaporize. A liposome's unique property is that it can entrap both hydrophobic and hydrophilic substances simultaneously in the lipid bilayer and the aqueous core, respectively. These stimuli-responsive liposomes can be triggered externally with ultrasound, to release the chemotherapeutic cargo only at the required site. This research aims to formulate echogenic liposomes encapsulating 5-FU for potential ultrasound triggered release (echogenic). Liposome formulations wereprepared with lipid composition of crude soybean lecithin and cholesterol by thin-filmhydration method and the drug was passively loaded in the formulation. The 5-FU loadedliposomes were evaluated by dynamic light scattering (DLS) for particle size, polydispersityindex, and zeta potential and transmission electron microscopy (TEM) for morphology.Encapsulated liposomal formulations were also evaluated using physicochemical techniquesincluding thermogravimetric analysis (TGA), differential scanning calorimetry (DSC),Fourier-transform infrared spectroscopy (FTIR), and X-ray diffraction (XRD). Theencapsulation efficiency and release kinetics were studied using a validated high-performanceliquid chromatography (HPLC) method. Echogenic properties were explored by entrapping abiocompatible gas (argon) at the same time as the drug (5-FU) using a pressure/freezemethodology. The liposomal formulations were typically spherical with a size of about 150 nmand encapsulation efficiency of 62%. Low-frequency ultrasound (20 kHz) was used to triggerthe drug release from the complete formulation at 10%, 15%, and 20% amplitude and exposuretime of 5 min and 10 min. The rate of drug release from the nano-carrier was a function of theultrasound amplitude and exposure time and reached a maximum of 65% release under theconditions investigated. The cumulative release was investigated, with and without theapplication of ultrasound. It was demonstrated that the application of ultrasound resulted in complete release (99%) after 12 h while this dropped to 70% without ultrasound. These results are encouraging for optimizing ultrasound parameters for triggered and controlled release of the 5-FU, for conditions such as the management of cancer where low-power ultrasound can be applied. , Thesis (MSc) -- Faculty of Science, Chemistry, 2021
- Full Text:
- Date Issued: 2021-10
- Authors: Izuchukwu, Ezekiel Charles
- Date: 2021-10
- Subjects: Liposomes , Drug delivery systems , Colon (Anatomy) Cancer Treatment , Transmission electron microscopy , Fourier transform infrared spectroscopy , Liquid chromatography , Echogenic liposomes , Ultrasound-triggered drug delivery
- Language: English
- Type: Masters theses , text
- Identifier: http://hdl.handle.net/10962/188997 , vital:44805
- Description: Colorectal cancer is one of common cancers worldwide. It is the third most diagnosed cancer and the second leading cause of death. The use of 5-fluorouracil (5-FU) alone or in a chemotherapy regime has been the effective treatment of colorectal cancer patients. The efficacy of 5-FU in colorectal cancer treatment is significantly limited by drug resistance, gastrointestinal, and bone marrow toxicity through high-level expression of thymidylate synthase, justifying a need to improve its therapeutic index. Liposomes are colloidal membranes comprising of one or more lipid bilayers enclosing an aqueous core. They have been used to improve the therapeutic index of many anti-cancer drugs by changing drug absorption, elongating biological half-life, reducing metabolism, and reducing toxicity to healthy tissues. Echogenic liposomes are specifically designed to respond to external triggering like ultrasound stimulation by entrapping a gas or an emulsion that can vaporize. A liposome's unique property is that it can entrap both hydrophobic and hydrophilic substances simultaneously in the lipid bilayer and the aqueous core, respectively. These stimuli-responsive liposomes can be triggered externally with ultrasound, to release the chemotherapeutic cargo only at the required site. This research aims to formulate echogenic liposomes encapsulating 5-FU for potential ultrasound triggered release (echogenic). Liposome formulations wereprepared with lipid composition of crude soybean lecithin and cholesterol by thin-filmhydration method and the drug was passively loaded in the formulation. The 5-FU loadedliposomes were evaluated by dynamic light scattering (DLS) for particle size, polydispersityindex, and zeta potential and transmission electron microscopy (TEM) for morphology.Encapsulated liposomal formulations were also evaluated using physicochemical techniquesincluding thermogravimetric analysis (TGA), differential scanning calorimetry (DSC),Fourier-transform infrared spectroscopy (FTIR), and X-ray diffraction (XRD). Theencapsulation efficiency and release kinetics were studied using a validated high-performanceliquid chromatography (HPLC) method. Echogenic properties were explored by entrapping abiocompatible gas (argon) at the same time as the drug (5-FU) using a pressure/freezemethodology. The liposomal formulations were typically spherical with a size of about 150 nmand encapsulation efficiency of 62%. Low-frequency ultrasound (20 kHz) was used to triggerthe drug release from the complete formulation at 10%, 15%, and 20% amplitude and exposuretime of 5 min and 10 min. The rate of drug release from the nano-carrier was a function of theultrasound amplitude and exposure time and reached a maximum of 65% release under theconditions investigated. The cumulative release was investigated, with and without theapplication of ultrasound. It was demonstrated that the application of ultrasound resulted in complete release (99%) after 12 h while this dropped to 70% without ultrasound. These results are encouraging for optimizing ultrasound parameters for triggered and controlled release of the 5-FU, for conditions such as the management of cancer where low-power ultrasound can be applied. , Thesis (MSc) -- Faculty of Science, Chemistry, 2021
- Full Text:
- Date Issued: 2021-10
The geology, mineralogy, structure and economic aspects of the pegmatite-hosted Swanson Tantalum Deposit, Tantalite Valley area, southern Namibia
- Authors: Pepler, Laubser
- Date: 2022-04-06
- Subjects: Pegmatites South Africa Pofadder (Region) , Tantalum South Africa Pofadder (Region) , Geology South Africa Pofadder (Region) , Mineralogy South Africa Pofadder (Region) , Pegmatites South Africa Pofadder (Region) Structure , Pegmatites Economic aspects South Africa Pofadder (Region) , Pofadder Shear Zone , Tantalite Valley Complex , Orange River Pegmatite Belt , Lower Fish River/Onseepkans Thrust Zone
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/291303 , vital:56843
- Description: This study presents the geology, mineralogy, structure, and economic aspects of the recently explored Swanson Tantalum Deposit occurring within the Namaqua Sector of the Namaqua Natal Metamorphic Province, Tantalite Valley area, southern Namibia. It is an LCT-type pegmatite hosted (microlitetantalite- tapiolite ± spodumene – lepidolite - zinnwaldite) tantalum deposit forming part of a highly localised sill-and-dyke swarm comprised of 15 shallow dipping and significantly mineralised pegmatites. This deposit forms part of the western portions of the regionally developed∼ 1040 – 950 Ma Orange River Pegmatite Belt (ORPB) which was locally emplaced syn-tectonically into competent host rocks in the core zone of the late-stage crustal scale transcurrent dextral, ductile to brittle-ductile D4 Marshall Rocks – Pofadder Shear Zone (MRPSZ), where it crosscuts the rocks of the D2 Lower Fish River - Onseepkans Thrust Zone (LFROTZ). A JORC Maiden Mineral Resource of 1.2 Mt @ 412 ppm Ta2O5 + 76 ppm Nb2O5 + 0.29 wt. % Li2O (with an applied cut-off grade of 236 ppm Ta2O5 and a minimum thickness of 1 m) has recently been estimated for the deposit. The deposit is currently being advanced to feasibility stage with the aim of outlining economic Mineral Reserves. It currently hosts a globally significant and market-relevant “high grade – low tonnage” tantalum Mineral Resource. Recent litho-structural mapping of this deposit has shown that its structural setting encompasses a locally developed lower strain extensional quadrant associated with the mega-scale shear zone bound competent mantle porphyroclast: the mafic-ultramafic Tantalite Valley Complex (TVC), or TVC megaclast. A succession of syn-D4 MRPSZ-hosted granitic melts comprising earlier leucogranite intrusions and later mineralised pegmatites of the Swanson Tantalum Deposit have variably utilised this extensional structure. The earlier leucogranites have clearly exploited mylonitic foliations associated with the development of core zone of the MRPSZ, while the mineralised pegmatites have utilised later-stage shallow-dipping Riedel fractures developed within more competent host rock. The tantalum tenor of pegmatites comprising the Swanson Tantalum Deposit is clearly structurally controlled, with tantalum tenor increasing from NW towards the SE over relatively short distances, toward the TVC megaclast. Although highly speculative without robust geochronological and petrographic investigation, field observations from this study highlights that the host rocks to the Swanson Tantalum Deposit, namely the mottled hybrid metagabbro (HMG), usually described as being syn-D2 in age (∼ 1200 – 1100 Ma), may possibly be syn-D4 in age (∼ 1040 – 950 Ma). If this is proven to be true, it may represent the earliest syn-D4 melt known for the MRPSZ. The Swanson Tantalum Deposit area therefore represents a prime area for studying and potentially constraining the upper and lower age limits of the MRPSZ. , Thesis (MSc) -- Faculty of Science, Geology, 2022
- Full Text:
- Date Issued: 2022-04-06
- Authors: Pepler, Laubser
- Date: 2022-04-06
- Subjects: Pegmatites South Africa Pofadder (Region) , Tantalum South Africa Pofadder (Region) , Geology South Africa Pofadder (Region) , Mineralogy South Africa Pofadder (Region) , Pegmatites South Africa Pofadder (Region) Structure , Pegmatites Economic aspects South Africa Pofadder (Region) , Pofadder Shear Zone , Tantalite Valley Complex , Orange River Pegmatite Belt , Lower Fish River/Onseepkans Thrust Zone
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/291303 , vital:56843
- Description: This study presents the geology, mineralogy, structure, and economic aspects of the recently explored Swanson Tantalum Deposit occurring within the Namaqua Sector of the Namaqua Natal Metamorphic Province, Tantalite Valley area, southern Namibia. It is an LCT-type pegmatite hosted (microlitetantalite- tapiolite ± spodumene – lepidolite - zinnwaldite) tantalum deposit forming part of a highly localised sill-and-dyke swarm comprised of 15 shallow dipping and significantly mineralised pegmatites. This deposit forms part of the western portions of the regionally developed∼ 1040 – 950 Ma Orange River Pegmatite Belt (ORPB) which was locally emplaced syn-tectonically into competent host rocks in the core zone of the late-stage crustal scale transcurrent dextral, ductile to brittle-ductile D4 Marshall Rocks – Pofadder Shear Zone (MRPSZ), where it crosscuts the rocks of the D2 Lower Fish River - Onseepkans Thrust Zone (LFROTZ). A JORC Maiden Mineral Resource of 1.2 Mt @ 412 ppm Ta2O5 + 76 ppm Nb2O5 + 0.29 wt. % Li2O (with an applied cut-off grade of 236 ppm Ta2O5 and a minimum thickness of 1 m) has recently been estimated for the deposit. The deposit is currently being advanced to feasibility stage with the aim of outlining economic Mineral Reserves. It currently hosts a globally significant and market-relevant “high grade – low tonnage” tantalum Mineral Resource. Recent litho-structural mapping of this deposit has shown that its structural setting encompasses a locally developed lower strain extensional quadrant associated with the mega-scale shear zone bound competent mantle porphyroclast: the mafic-ultramafic Tantalite Valley Complex (TVC), or TVC megaclast. A succession of syn-D4 MRPSZ-hosted granitic melts comprising earlier leucogranite intrusions and later mineralised pegmatites of the Swanson Tantalum Deposit have variably utilised this extensional structure. The earlier leucogranites have clearly exploited mylonitic foliations associated with the development of core zone of the MRPSZ, while the mineralised pegmatites have utilised later-stage shallow-dipping Riedel fractures developed within more competent host rock. The tantalum tenor of pegmatites comprising the Swanson Tantalum Deposit is clearly structurally controlled, with tantalum tenor increasing from NW towards the SE over relatively short distances, toward the TVC megaclast. Although highly speculative without robust geochronological and petrographic investigation, field observations from this study highlights that the host rocks to the Swanson Tantalum Deposit, namely the mottled hybrid metagabbro (HMG), usually described as being syn-D2 in age (∼ 1200 – 1100 Ma), may possibly be syn-D4 in age (∼ 1040 – 950 Ma). If this is proven to be true, it may represent the earliest syn-D4 melt known for the MRPSZ. The Swanson Tantalum Deposit area therefore represents a prime area for studying and potentially constraining the upper and lower age limits of the MRPSZ. , Thesis (MSc) -- Faculty of Science, Geology, 2022
- Full Text:
- Date Issued: 2022-04-06
Gray
- Authors: Fouché, James De Clerque
- Date: 2022-04-07
- Subjects: Creative writing (Higher education) South Africa , Diaries -- Authorship , Detective and mystery stories, South African (English) 21st century , South African fiction (English) 21st century , South African essays (English) 21st century , English fiction 20th century History and criticism , American fiction African American authors History and criticism , American fiction 20th century History and criticism
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/292715 , vital:57009
- Description: My thesis is a crime fiction novella. I’m moved by the idea of developing feasible, relatable characters with flaws – a staple of the crime fiction genre. I also appreciate how crime serves as a platform from which to launch into human drama, the way James Ellroy does in The Black Dahlia. While my protagonist endures trials on a near Jobian scale, the narrative meditates on the consequences of crime and conflict in a satirical way. Writers like Ross Macdonald, Raymond Chandler, Flannery O’Connor, China Miéville and Derek Raymond have inspired me with their sharp imagery and unconventional characterization techniques. These techniques accelerate the ease with which a reader can step into the shoes of any given narrator. Their writing is crisp, uncluttered and uncomplicated. , Thesis (MA) -- Faculty of Humanities, School of Languages and Literatures, 2022
- Full Text:
- Date Issued: 2022-04-07
- Authors: Fouché, James De Clerque
- Date: 2022-04-07
- Subjects: Creative writing (Higher education) South Africa , Diaries -- Authorship , Detective and mystery stories, South African (English) 21st century , South African fiction (English) 21st century , South African essays (English) 21st century , English fiction 20th century History and criticism , American fiction African American authors History and criticism , American fiction 20th century History and criticism
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/292715 , vital:57009
- Description: My thesis is a crime fiction novella. I’m moved by the idea of developing feasible, relatable characters with flaws – a staple of the crime fiction genre. I also appreciate how crime serves as a platform from which to launch into human drama, the way James Ellroy does in The Black Dahlia. While my protagonist endures trials on a near Jobian scale, the narrative meditates on the consequences of crime and conflict in a satirical way. Writers like Ross Macdonald, Raymond Chandler, Flannery O’Connor, China Miéville and Derek Raymond have inspired me with their sharp imagery and unconventional characterization techniques. These techniques accelerate the ease with which a reader can step into the shoes of any given narrator. Their writing is crisp, uncluttered and uncomplicated. , Thesis (MA) -- Faculty of Humanities, School of Languages and Literatures, 2022
- Full Text:
- Date Issued: 2022-04-07