Synthesis, characterization and in vitro antibacterial analysis of carvacrol based-hybrid analogues
- Authors: Mbese, Zintle
- Date: 2019
- Subjects: Medicinal plants Herbs -- Therapeutic use
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/14527 , vital:39998
- Description: he focus of this research was to synthesize and characterize carvacrol hybrid analogues. Twenty-one (21) carvacrol analogues were synthesized by reacting carvacrol with (1. 4- aminosalicylic acid, 2. ferrocene keto-butanoic acid, 3. Ferrocene butanoic acid, 4. succinic anhydride, 5. folic acid, 6. cinnamic acid, 7. leucovorin, 8. oleanolic acid, 9. artesunate, 10. cholesterol, 11. cholesterol succinate, 12. curcumin, 13. curcumin succinate, 14. zidovudine, 15. Zidovudine succinate, 16. 8-hydroxyquinoline, 17. 8-hydroxyquinoline succinate, 18. 2- (7-chloroquinolin-4-ylamino)ethyl 5-isopropyl-2-methylphenyl, 19. 2-(7-chloroquinolin-4- ylamino)ethyl 5-isopropyl-2-methylphenyl succinate, 20. 2-(2-(7-chloroquinolin-4- ylamino)ethoxy)ethyl 5-isopropyl-2-methylphenyl, 21. 2-(2-(7-chloroquinolin-4- ylamino)ethoxy)ethyl 5-isopropyl-2-methylphenyl succinate). The carvacrol analogues were characterized using FTIR, UHPLC-HRMS, 1H- and 13C-NMR spectroscopy. The antibacterial analysis was performed to evaluate the carvacrol analogues against bacterial strains. FTIR spectra of carvacrol analogues were found to exhibit peaks of C-O stretch and Ar-C in a range of 1014-1280 cm-1 and a range of 1414-1697 cm-1 which confirm the successful formation of esters. The proposed structures of carvacrol analogues were confirmed by the 1H- and 13C-NMR. The selected 1H-NMR signal for aromatic protons ranged at 6.00-8.95 ppm/δ. The selected 13C-NMR signal for ester carbon and aromatic carbons ranged at 160.0-175.0 ppm/δ and at 110.00-154.00 ppm/δ. The structures were also confirmed by UHPLC-HRMS. Carvacrol analogues exhibited the highest inhibitory effect against Gram-positive and Gram-negative tested bacterial strains.
- Full Text:
- Date Issued: 2019
- Authors: Mbese, Zintle
- Date: 2019
- Subjects: Medicinal plants Herbs -- Therapeutic use
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/14527 , vital:39998
- Description: he focus of this research was to synthesize and characterize carvacrol hybrid analogues. Twenty-one (21) carvacrol analogues were synthesized by reacting carvacrol with (1. 4- aminosalicylic acid, 2. ferrocene keto-butanoic acid, 3. Ferrocene butanoic acid, 4. succinic anhydride, 5. folic acid, 6. cinnamic acid, 7. leucovorin, 8. oleanolic acid, 9. artesunate, 10. cholesterol, 11. cholesterol succinate, 12. curcumin, 13. curcumin succinate, 14. zidovudine, 15. Zidovudine succinate, 16. 8-hydroxyquinoline, 17. 8-hydroxyquinoline succinate, 18. 2- (7-chloroquinolin-4-ylamino)ethyl 5-isopropyl-2-methylphenyl, 19. 2-(7-chloroquinolin-4- ylamino)ethyl 5-isopropyl-2-methylphenyl succinate, 20. 2-(2-(7-chloroquinolin-4- ylamino)ethoxy)ethyl 5-isopropyl-2-methylphenyl, 21. 2-(2-(7-chloroquinolin-4- ylamino)ethoxy)ethyl 5-isopropyl-2-methylphenyl succinate). The carvacrol analogues were characterized using FTIR, UHPLC-HRMS, 1H- and 13C-NMR spectroscopy. The antibacterial analysis was performed to evaluate the carvacrol analogues against bacterial strains. FTIR spectra of carvacrol analogues were found to exhibit peaks of C-O stretch and Ar-C in a range of 1014-1280 cm-1 and a range of 1414-1697 cm-1 which confirm the successful formation of esters. The proposed structures of carvacrol analogues were confirmed by the 1H- and 13C-NMR. The selected 1H-NMR signal for aromatic protons ranged at 6.00-8.95 ppm/δ. The selected 13C-NMR signal for ester carbon and aromatic carbons ranged at 160.0-175.0 ppm/δ and at 110.00-154.00 ppm/δ. The structures were also confirmed by UHPLC-HRMS. Carvacrol analogues exhibited the highest inhibitory effect against Gram-positive and Gram-negative tested bacterial strains.
- Full Text:
- Date Issued: 2019
Synthesis, characterization and photodynamic activity of Sn (iv) triarylcorroles with red-shifted Q bands
- Babu, Balaji, Prinsloo, Earl, Mack, John, Nyokong, Tebello
- Authors: Babu, Balaji , Prinsloo, Earl , Mack, John , Nyokong, Tebello
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/187521 , vital:44668 , xlink:href="https://doi.org/10.1039/C9NJ03391B"
- Description: Two Sn(IV) triarylcorroles were synthesised and characterized. The absorption spectrum of a meso-thien-2-yl substituted tin(IV)corrole (1-Sn) is red shifted compared to its phenyl analogue (2-Sn) and shows no sign of aggregation in solution. 1-Sn and 2-Sn exhibited singlet oxygen quantum yields of 0.87 and 0.54 in DMF, and have a triplet lifetime of 31 and 50 μs, respectively. Time dependent cellular uptake in MCF-7 cells for 1-Sn reached a peak at 24 h, and 1-Sn was found to be more lipophilic than 2-Sn. 1-Sn showed good photo-cytotoxicity on exposure to a Thorlabs 625 nm LED with an IC50 value of 3.2 μM and remained inactive in the dark.
- Full Text:
- Date Issued: 2019
- Authors: Babu, Balaji , Prinsloo, Earl , Mack, John , Nyokong, Tebello
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/187521 , vital:44668 , xlink:href="https://doi.org/10.1039/C9NJ03391B"
- Description: Two Sn(IV) triarylcorroles were synthesised and characterized. The absorption spectrum of a meso-thien-2-yl substituted tin(IV)corrole (1-Sn) is red shifted compared to its phenyl analogue (2-Sn) and shows no sign of aggregation in solution. 1-Sn and 2-Sn exhibited singlet oxygen quantum yields of 0.87 and 0.54 in DMF, and have a triplet lifetime of 31 and 50 μs, respectively. Time dependent cellular uptake in MCF-7 cells for 1-Sn reached a peak at 24 h, and 1-Sn was found to be more lipophilic than 2-Sn. 1-Sn showed good photo-cytotoxicity on exposure to a Thorlabs 625 nm LED with an IC50 value of 3.2 μM and remained inactive in the dark.
- Full Text:
- Date Issued: 2019
Systematic review of rural health development research in South Africa
- Authors: van Rooyen, Rize Dorothea
- Date: 2019
- Subjects: Rural health services -- South Africa , Rural development -- South Africa Health -- Research -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10948/44112 , vital:37112
- Description: The challenges presented by the contextual realities of rurality on the South African rural health care system are important to the understanding of the poor health outcomes of these populations. Nonetheless, much research has been done on South African rural health. The vast amount of information, studies and policies regarding South African rural health, and its development made it ideal to be studied by systematic review. This systematic review through its adaption of a mixed methods approach, reviewed a sample of the South African rural health development research outputs between 2013 and 2018, in addition to practitioner-led research and policies. Twelve key systematic review steps were developed to assist in executing the research. In addition, a complete research protocol was part of the systematic review steps. The review protocol indicated the strategies utilised in the scoping searches, data collection and synthesis processes of the review. The findings of this research consisted of three synthesis processes. The first synthesis consisted of the presentation of the qualitative findings and the interpretation thereof. The second synthesis process compared the key themes extracted from the data outputs to those extracted from the grey literature, and the third synthesis integrated the quantitative and qualitative findings into a single review. The review found that although research and practice were aligned to an extent, there were important areas of research, which had been largely overlooked. These included areas such as participation of advocacy, training and education as well as rural-proofing. It further showed that academic research in the field of rural health development relied heavily on participant dependent research methods thereby limiting the exposure of researchers to the phenomena being studied. This review’s methodology and protocol could serve as a guideline for future researchers. The prioritisation of rural health needs and the inclusion of rurality as a variable in South African healthcare policy and strategy is essential in health development research.
- Full Text:
- Date Issued: 2019
- Authors: van Rooyen, Rize Dorothea
- Date: 2019
- Subjects: Rural health services -- South Africa , Rural development -- South Africa Health -- Research -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10948/44112 , vital:37112
- Description: The challenges presented by the contextual realities of rurality on the South African rural health care system are important to the understanding of the poor health outcomes of these populations. Nonetheless, much research has been done on South African rural health. The vast amount of information, studies and policies regarding South African rural health, and its development made it ideal to be studied by systematic review. This systematic review through its adaption of a mixed methods approach, reviewed a sample of the South African rural health development research outputs between 2013 and 2018, in addition to practitioner-led research and policies. Twelve key systematic review steps were developed to assist in executing the research. In addition, a complete research protocol was part of the systematic review steps. The review protocol indicated the strategies utilised in the scoping searches, data collection and synthesis processes of the review. The findings of this research consisted of three synthesis processes. The first synthesis consisted of the presentation of the qualitative findings and the interpretation thereof. The second synthesis process compared the key themes extracted from the data outputs to those extracted from the grey literature, and the third synthesis integrated the quantitative and qualitative findings into a single review. The review found that although research and practice were aligned to an extent, there were important areas of research, which had been largely overlooked. These included areas such as participation of advocacy, training and education as well as rural-proofing. It further showed that academic research in the field of rural health development relied heavily on participant dependent research methods thereby limiting the exposure of researchers to the phenomena being studied. This review’s methodology and protocol could serve as a guideline for future researchers. The prioritisation of rural health needs and the inclusion of rurality as a variable in South African healthcare policy and strategy is essential in health development research.
- Full Text:
- Date Issued: 2019
Targeted attack detection by means of free and open source solutions
- Authors: Bernardo, Louis F
- Date: 2019
- Subjects: Computer networks -- Security measures , Information technology -- Security measures , Computer security -- Management , Data protection
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/92269 , vital:30703
- Description: Compliance requirements are part of everyday business requirements for various areas, such as retail and medical services. As part of compliance it may be required to have infrastructure in place to monitor the activities in the environment to ensure that the relevant data and environment is sufficiently protected. At the core of such monitoring solutions one would find some type of data repository, or database, to store and ultimately correlate the captured events. Such solutions are commonly called Security Information and Event Management, or SIEM for short. Larger companies have been known to use commercial solutions such as IBM's Qradar, Logrythm, or Splunk. However, these come at significant cost and arent suitable for smaller businesses with limited budgets. These solutions require manual configuration of event correlation for detection of activities that place the environment in danger. This usually requires vendor implementation assistance that also would come at a cost. Alternatively, there are open source solutions that provide the required functionality. This research will demonstrate building an open source solution, with minimal to no cost for hardware or software, while still maintaining the capability of detecting targeted attacks. The solution presented in this research includes Wazuh, which is a combination of OSSEC and the ELK stack, integrated with an Network Intrusion Detection System (NIDS). The success of the integration, is determined by measuring postive attack detection based on each different configuration options. To perform the testing, a deliberately vulnerable platform named Metasploitable will be used as a victim host. The victim host vulnerabilities were created specifically to serve as target for Metasploit. The attacks were generated by utilising Metasploit Framework on a prebuilt Kali Linux host.
- Full Text:
- Date Issued: 2019
- Authors: Bernardo, Louis F
- Date: 2019
- Subjects: Computer networks -- Security measures , Information technology -- Security measures , Computer security -- Management , Data protection
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/92269 , vital:30703
- Description: Compliance requirements are part of everyday business requirements for various areas, such as retail and medical services. As part of compliance it may be required to have infrastructure in place to monitor the activities in the environment to ensure that the relevant data and environment is sufficiently protected. At the core of such monitoring solutions one would find some type of data repository, or database, to store and ultimately correlate the captured events. Such solutions are commonly called Security Information and Event Management, or SIEM for short. Larger companies have been known to use commercial solutions such as IBM's Qradar, Logrythm, or Splunk. However, these come at significant cost and arent suitable for smaller businesses with limited budgets. These solutions require manual configuration of event correlation for detection of activities that place the environment in danger. This usually requires vendor implementation assistance that also would come at a cost. Alternatively, there are open source solutions that provide the required functionality. This research will demonstrate building an open source solution, with minimal to no cost for hardware or software, while still maintaining the capability of detecting targeted attacks. The solution presented in this research includes Wazuh, which is a combination of OSSEC and the ELK stack, integrated with an Network Intrusion Detection System (NIDS). The success of the integration, is determined by measuring postive attack detection based on each different configuration options. To perform the testing, a deliberately vulnerable platform named Metasploitable will be used as a victim host. The victim host vulnerabilities were created specifically to serve as target for Metasploit. The attacks were generated by utilising Metasploit Framework on a prebuilt Kali Linux host.
- Full Text:
- Date Issued: 2019
Targeting allosteric sites of Escherichia coli heat shock protein 70 for antibiotic development
- Authors: Okeke, Chiamaka Jessica
- Date: 2019
- Subjects: Heat shock proteins , Escherichia coli , Allosteric proteins , Antibiotics , Molecular chaperones , Ligands (Biochemistry) , Molecular dynamics , Principal components analysis , South African Natural Compounds Database
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/115998 , vital:34287
- Description: Hsp70s are members of the heat shock proteins family with a molecular weight of 70-kDa and are the most abundant group in bacterial and eukaryotic systems, hence the most extensively studied ones. These proteins are molecular chaperones that play a significant role in protein homeostasis by facilitating appropriate folding of proteins, preventing proteins from aggregating and misfolding. They are also involved in translocation of proteins into subcellular compartments and protection of cells against stress. Stress caused by environmental or biological factors affects the functionality of the cell. In response to these stressful conditions, up-regulation of Hsp70s ensures that the cells are protected by balancing out unfolded proteins giving them ample time to repair denatured proteins. Hsp70s is connected to numerous illnesses such as autoimmune and neurodegenerative diseases, bacterial infection, cancer, malaria, and obesity. The multi-functional nature of Hsp70s predisposes them as promising therapeutic targets. Hsp70s play vital roles in various cell developments, and survival pathways, therefore targeting this protein will provide a new avenue towards the discovery of active therapeutic agents for the treatment of a wide range of diseases. Allosteric sites of these proteins in its multi-conformational states have not been explored for inhibitory properties hence the aim of this study. This study aims at identifying allosteric sites that inhibit the ATPase and substrate binding activities using computational approaches. Using E. coli as a model organism, molecular docking for high throughput virtual screening was carried out using 623 compounds from the South African Natural Compounds Database (SANCDB; https://sancdb.rubi.ru.ac.za/) against identified allosteric sites. Ligands with the highest binding affinity (good binders) interacting with critical allosteric residues that are druggable were identified. Molecular dynamics (MD) simulation was also performed on the identified hits to assess for protein-inhibitor complex stability. Finally, principal component analysis (PCA) was performed to understand the structural dynamics of the ligand-free and ligand-bound structures during MD simulation.
- Full Text:
- Date Issued: 2019
- Authors: Okeke, Chiamaka Jessica
- Date: 2019
- Subjects: Heat shock proteins , Escherichia coli , Allosteric proteins , Antibiotics , Molecular chaperones , Ligands (Biochemistry) , Molecular dynamics , Principal components analysis , South African Natural Compounds Database
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/115998 , vital:34287
- Description: Hsp70s are members of the heat shock proteins family with a molecular weight of 70-kDa and are the most abundant group in bacterial and eukaryotic systems, hence the most extensively studied ones. These proteins are molecular chaperones that play a significant role in protein homeostasis by facilitating appropriate folding of proteins, preventing proteins from aggregating and misfolding. They are also involved in translocation of proteins into subcellular compartments and protection of cells against stress. Stress caused by environmental or biological factors affects the functionality of the cell. In response to these stressful conditions, up-regulation of Hsp70s ensures that the cells are protected by balancing out unfolded proteins giving them ample time to repair denatured proteins. Hsp70s is connected to numerous illnesses such as autoimmune and neurodegenerative diseases, bacterial infection, cancer, malaria, and obesity. The multi-functional nature of Hsp70s predisposes them as promising therapeutic targets. Hsp70s play vital roles in various cell developments, and survival pathways, therefore targeting this protein will provide a new avenue towards the discovery of active therapeutic agents for the treatment of a wide range of diseases. Allosteric sites of these proteins in its multi-conformational states have not been explored for inhibitory properties hence the aim of this study. This study aims at identifying allosteric sites that inhibit the ATPase and substrate binding activities using computational approaches. Using E. coli as a model organism, molecular docking for high throughput virtual screening was carried out using 623 compounds from the South African Natural Compounds Database (SANCDB; https://sancdb.rubi.ru.ac.za/) against identified allosteric sites. Ligands with the highest binding affinity (good binders) interacting with critical allosteric residues that are druggable were identified. Molecular dynamics (MD) simulation was also performed on the identified hits to assess for protein-inhibitor complex stability. Finally, principal component analysis (PCA) was performed to understand the structural dynamics of the ligand-free and ligand-bound structures during MD simulation.
- Full Text:
- Date Issued: 2019
Taxonomic and trait-based responses of the orders Ephemeroptera, Plecoptera, Odonata, And Trichoptera (EPOT) to sediment stress in the Tsitsa River and its tributaries, Eastern Cape, South Africa
- Akamagwuna, Frank Chukwuzuoke
- Authors: Akamagwuna, Frank Chukwuzuoke
- Date: 2019
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/68082 , vital:29196
- Description: Increased urbanization and industrialisation due to human population growth and associated high demand for food have led to widespread disturbances of freshwater ecosystems and associated resources. A widely recognised consequence of these disturbances is the excessive delivery of sediments into the freshwater ecosystems, which severely affects the functioning and integrity of these systems.. The major water quality impairment in the Tsitsa River and its tributaries, situated in the Mzimvubu catchment in the Eastern Cape Province of South Africa, is known to be excessive sediment input. In this study, the application of macroinvertebrates taxonomic-based and trait-based approaches was used to assess the responses and vulnerability of Ephemeroptera, Plecoptera, Odonata and Trichoptera (EPOT) species to settled and suspended sediments stress in eight selected sampling sites in the Tsitsa River and its tributaries. The eight selected sites were Site 1 (Tsitsa upstream), Site 2 (Tsitsa downstream), Site 3 (Qurana tributary), Site 4 (Pot River upstream), Site 5 (Pot River downstream), Site 6 (Little Pot River), Site 7 (Millstream upstream) and Site 8 (Millstream downstream). The methods used in this study involved the analysis of water physico-chemical variables as well as sediment characteristics, derivation of five EPOT metrics, EPOT species-level taxonomic analysis, individual EPOT trait analysis and the development of a novel trait-based approach using a combination of traits. The sampling of EPOT taxa was done using the SASS5 protocols. Identification of EPOT was done to genus/species level and all data were subjected to relevant statistical analysis. The results of ecological categories derived for the physico-chemical variables generally indicated the ecological categories A and B, which was indicative of good water quality conditions. The result of sediment particle analysis revealed four distinct site groups: site group 1 (Tsitsa River upstream and Qurana tributary), site group 2 (Tsitsa River downstream and Millstream upstream), site group 3 (Pot River, both upstream and downstream, and Millstream downstream) and site group 4 (Little Pot River). The species-level taxonomic analysis of EPOT revealed that site group 1 was the most sediment-influenced sites whereas site group 4 was the least sediment-influenced. Species such as Paragopmhus sp., Aeshna sp. and Baetis sp. were considered sediment-tolerant with strong positive association with site group 1. The novel trait-based approach developed in this study proved useful in predicting the responses of EPOT species to sediment stress, and further discriminated between the study sites. The approach was used to group EPOT species into four vulnerability classes. The result showed that filter feeding EPOT species that have filamentous gills, preferring stone biotopes and feeding on detritus (FPOM) were mostly classified as highly vulnerable to sediment stress and indicated no significant association with the highly sediment-influenced site group 1. The TBA largely corresponded well to the predictions made with the relative abundance of the vulnerable class decreasing in the sediment-influenced sites compared to the tolerant and highly tolerant classes. Overall, the study revealed the importance of the complementary use of taxonomic and trait-based approaches to biomonitoring.
- Full Text:
- Date Issued: 2019
- Authors: Akamagwuna, Frank Chukwuzuoke
- Date: 2019
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/68082 , vital:29196
- Description: Increased urbanization and industrialisation due to human population growth and associated high demand for food have led to widespread disturbances of freshwater ecosystems and associated resources. A widely recognised consequence of these disturbances is the excessive delivery of sediments into the freshwater ecosystems, which severely affects the functioning and integrity of these systems.. The major water quality impairment in the Tsitsa River and its tributaries, situated in the Mzimvubu catchment in the Eastern Cape Province of South Africa, is known to be excessive sediment input. In this study, the application of macroinvertebrates taxonomic-based and trait-based approaches was used to assess the responses and vulnerability of Ephemeroptera, Plecoptera, Odonata and Trichoptera (EPOT) species to settled and suspended sediments stress in eight selected sampling sites in the Tsitsa River and its tributaries. The eight selected sites were Site 1 (Tsitsa upstream), Site 2 (Tsitsa downstream), Site 3 (Qurana tributary), Site 4 (Pot River upstream), Site 5 (Pot River downstream), Site 6 (Little Pot River), Site 7 (Millstream upstream) and Site 8 (Millstream downstream). The methods used in this study involved the analysis of water physico-chemical variables as well as sediment characteristics, derivation of five EPOT metrics, EPOT species-level taxonomic analysis, individual EPOT trait analysis and the development of a novel trait-based approach using a combination of traits. The sampling of EPOT taxa was done using the SASS5 protocols. Identification of EPOT was done to genus/species level and all data were subjected to relevant statistical analysis. The results of ecological categories derived for the physico-chemical variables generally indicated the ecological categories A and B, which was indicative of good water quality conditions. The result of sediment particle analysis revealed four distinct site groups: site group 1 (Tsitsa River upstream and Qurana tributary), site group 2 (Tsitsa River downstream and Millstream upstream), site group 3 (Pot River, both upstream and downstream, and Millstream downstream) and site group 4 (Little Pot River). The species-level taxonomic analysis of EPOT revealed that site group 1 was the most sediment-influenced sites whereas site group 4 was the least sediment-influenced. Species such as Paragopmhus sp., Aeshna sp. and Baetis sp. were considered sediment-tolerant with strong positive association with site group 1. The novel trait-based approach developed in this study proved useful in predicting the responses of EPOT species to sediment stress, and further discriminated between the study sites. The approach was used to group EPOT species into four vulnerability classes. The result showed that filter feeding EPOT species that have filamentous gills, preferring stone biotopes and feeding on detritus (FPOM) were mostly classified as highly vulnerable to sediment stress and indicated no significant association with the highly sediment-influenced site group 1. The TBA largely corresponded well to the predictions made with the relative abundance of the vulnerable class decreasing in the sediment-influenced sites compared to the tolerant and highly tolerant classes. Overall, the study revealed the importance of the complementary use of taxonomic and trait-based approaches to biomonitoring.
- Full Text:
- Date Issued: 2019
Teacher practices and human capital acquisition: evidence from the international association for evaluation of educational achievement
- Authors: Tsikai,Epiphania
- Date: 2019
- Subjects: Human capital Academic achievement
- Language: English
- Type: Thesis , Masters , MCom (Economics)
- Identifier: http://hdl.handle.net/10353/17011 , vital:40811
- Description: Human capital is considered as the measure of education, skills, capacity and attributes of labour which impact people’s productive capacity and earning potential. The study used mathematics student academic performance as a proxy to measure human capital across countries using the Trends in International Mathematics and Science study (TIMSS) dataset. African countries participating in TIMSS are performing poorly as they are always at the bottom. The budget allocation of African countries is more than that of Asian countries, but the student outcomes do not correlate with the input. This is so disappointing considering the amount of money the governments invest in the education sectors. The study investigated teacher practices and human capital acquisition in four African countries that participated in TIMSS from 2007 to 2015. The four countries were South Africa, Botswana, Egypt and Morocco. In addition, the study included the best performing countries from East Asia that also participated in TIMSS. These four countries were Singapore, South Korea, Japan and Hong Kong Sar. The best performing countries were included in the analysis in order to determine best practice from the best performing countries. Using Stata 14, pooled OLS cross sections methodology was used to generate results on whether teacher practices influence students’ mathematics achievement by using grade 8 test scores per country, student and teacher background. The study found that some teacher practices significantly explain academic performance in mathematics especially in African countries whilst socio economic status significantly affect performance across all the countries. Future research will investigate some other measures that can promote good performance of mathematics in African countries.
- Full Text:
- Date Issued: 2019
- Authors: Tsikai,Epiphania
- Date: 2019
- Subjects: Human capital Academic achievement
- Language: English
- Type: Thesis , Masters , MCom (Economics)
- Identifier: http://hdl.handle.net/10353/17011 , vital:40811
- Description: Human capital is considered as the measure of education, skills, capacity and attributes of labour which impact people’s productive capacity and earning potential. The study used mathematics student academic performance as a proxy to measure human capital across countries using the Trends in International Mathematics and Science study (TIMSS) dataset. African countries participating in TIMSS are performing poorly as they are always at the bottom. The budget allocation of African countries is more than that of Asian countries, but the student outcomes do not correlate with the input. This is so disappointing considering the amount of money the governments invest in the education sectors. The study investigated teacher practices and human capital acquisition in four African countries that participated in TIMSS from 2007 to 2015. The four countries were South Africa, Botswana, Egypt and Morocco. In addition, the study included the best performing countries from East Asia that also participated in TIMSS. These four countries were Singapore, South Korea, Japan and Hong Kong Sar. The best performing countries were included in the analysis in order to determine best practice from the best performing countries. Using Stata 14, pooled OLS cross sections methodology was used to generate results on whether teacher practices influence students’ mathematics achievement by using grade 8 test scores per country, student and teacher background. The study found that some teacher practices significantly explain academic performance in mathematics especially in African countries whilst socio economic status significantly affect performance across all the countries. Future research will investigate some other measures that can promote good performance of mathematics in African countries.
- Full Text:
- Date Issued: 2019
Teachers and learners’ perspectives towards English as a language of learning and teaching : a case of two selected secondary schools in the Amathole West Education District
- Osunkunle, Atinuke Oluwatoyin
- Authors: Osunkunle, Atinuke Oluwatoyin
- Date: 2019
- Subjects: English language -- Study and teaching Second language acquisition
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: http://hdl.handle.net/10353/16243 , vital:40702
- Description: The study aimed at examining teachers and learners’ perspectives towards English as a language of learning and teaching (LoLT), using two selected secondary schools in the Amathole West Education District as a case study and to see if English is indeed a language of choice among learners and teachers. The researcher employed an interpretative qualitative research paradigm and purposive non-probability sampling method was used to draw samples of participants for in-depth interviews and focus group discussions. The school principal and two teachers were purposively selected in each of the two schools, making a total of two school principals and four teachers that were interviewed. In addition, a member of the School Governing Body (SGB) was selected in each of the two schools and interviewed. The study also had one focus group discussion with learners in each of the two selected schools, making two focus groups in total. All the one-on-one in-depth interviews as well as the focus group discussions with the learners were recorded and then transcribed. The collected data was later analysed thematically to infer the meaning and present the findings. The findings revealed that most of the students in public schools are torn between two divides as they struggle with the use of English as a language of learning and teaching but seem to have no choice, as they all believed that the use of English is quite beneficial to them in many ways. Another critical finding is that some teachers find it difficult to teach in English because they do not have a good command of the language. This makes them to code-switch regularly using IsiXhosa along with English while they are supposed to teach in English. Thus, this affects the learners proper understanding of and grounding in the English language. The study also found out that the schools lack adequate support to ensure the effective use of English for learning and teaching. The study recommended that various support systems from the government are needed in order to ensure the acceptance and successful use of English as LoLT in South African public schools. In this regard, the participants assured that these would result in positive outcomes, as they would provide quality education through government support. The study concluded that English is the preferred LoLT by both teachers and learners, thus, it needs to be prioritised.
- Full Text:
- Date Issued: 2019
- Authors: Osunkunle, Atinuke Oluwatoyin
- Date: 2019
- Subjects: English language -- Study and teaching Second language acquisition
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: http://hdl.handle.net/10353/16243 , vital:40702
- Description: The study aimed at examining teachers and learners’ perspectives towards English as a language of learning and teaching (LoLT), using two selected secondary schools in the Amathole West Education District as a case study and to see if English is indeed a language of choice among learners and teachers. The researcher employed an interpretative qualitative research paradigm and purposive non-probability sampling method was used to draw samples of participants for in-depth interviews and focus group discussions. The school principal and two teachers were purposively selected in each of the two schools, making a total of two school principals and four teachers that were interviewed. In addition, a member of the School Governing Body (SGB) was selected in each of the two schools and interviewed. The study also had one focus group discussion with learners in each of the two selected schools, making two focus groups in total. All the one-on-one in-depth interviews as well as the focus group discussions with the learners were recorded and then transcribed. The collected data was later analysed thematically to infer the meaning and present the findings. The findings revealed that most of the students in public schools are torn between two divides as they struggle with the use of English as a language of learning and teaching but seem to have no choice, as they all believed that the use of English is quite beneficial to them in many ways. Another critical finding is that some teachers find it difficult to teach in English because they do not have a good command of the language. This makes them to code-switch regularly using IsiXhosa along with English while they are supposed to teach in English. Thus, this affects the learners proper understanding of and grounding in the English language. The study also found out that the schools lack adequate support to ensure the effective use of English for learning and teaching. The study recommended that various support systems from the government are needed in order to ensure the acceptance and successful use of English as LoLT in South African public schools. In this regard, the participants assured that these would result in positive outcomes, as they would provide quality education through government support. The study concluded that English is the preferred LoLT by both teachers and learners, thus, it needs to be prioritised.
- Full Text:
- Date Issued: 2019
Teachers’ beliefs and classroom practices about their oral and written corrective feedback strategies in selected peri-urban and rural schools in Umguza district in Zimbabwe.
- Authors: Green , Flosie Florence
- Date: 2019
- Subjects: Teachers Classroom management
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/17987 , vital:42001
- Description: The goal of the study was to examine teachers’ beliefs and classroom practices about their corrective feedback strategies in selected peri-urban rural schools in Umguza District in Zimbabwe, in order to draw up a Corrective Feedback model aimed at enhancing ESL proficiency among O’ level school pupils. The study has been necessitated by challenges which post O’ level students face when communicating in English at institutions of higher learning. The study used the mixed research approach, whereby both quantitative and qualitative methods of gathering data were used though the dominant approach was the qualitative approach. Data was collected through questionnaires, semi structured interviews, lesson observations and examination of pupils’ written exercises. The questionnaire was completed by twenty two teachers. Semi-structured interviews were held with six teachers from the selected schools, while nine lesson observations were done and eighty exercise books were scrutinized for the presence of written Corrective Feedback. Results obtained showed that teachers’ stated beliefs about corrective feedback were not always demonstrated in their classroom practices. Furthermore the study revealed that oral Corrective Feedback was not used consistently in addition to a lack of uniformity in both the usage and interpretation of written Corrective Feedback. Results obtained showed that teachers’ stated beliefs about Corrective Feedback were not always demonstrated in their classroom practices. In addition, the study also revealed that some teachers were not aware of the codes used in written Corrective Feedback and their meaning. The conclusion reached in this study was that vi there is need for a more informed and consistent usage of Corrective Feedback among teachers. In the light of this finding, a Corrective Feedback model was suggested to assist teachers apply Corrective Feedback more consistently and more productively. A number of recommendations were made at the conclusion of this study. Firstly, it was recommended that marking codes be availed to teachers and pupils before the beginning of the school calendar. The contents of the advisory chart included in this study could be given to pupils to copy onto the back of their exercise books to enable them to interpret the feedback which the teachers would have written. It was recommended that teachers familiarise themselves with the developments in the use of CF in the ESL classroom. At school level this could be done through staff development workshop, where teachers share experiences about what works and what does not work in the ESL classroom. This should be done in view of the existing problem of communicative incompetency bedevilling pupils nationally. Secondly it was recommended that teachers familiarise themselves with the developments in the use of CF in the ESL classroom. The final recommendation was that teachers adopt minimal marking in the form of codes in order to cut down on turnaround time as well as stimulate individual learner automatisation of knowledge.
- Full Text:
- Date Issued: 2019
- Authors: Green , Flosie Florence
- Date: 2019
- Subjects: Teachers Classroom management
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/17987 , vital:42001
- Description: The goal of the study was to examine teachers’ beliefs and classroom practices about their corrective feedback strategies in selected peri-urban rural schools in Umguza District in Zimbabwe, in order to draw up a Corrective Feedback model aimed at enhancing ESL proficiency among O’ level school pupils. The study has been necessitated by challenges which post O’ level students face when communicating in English at institutions of higher learning. The study used the mixed research approach, whereby both quantitative and qualitative methods of gathering data were used though the dominant approach was the qualitative approach. Data was collected through questionnaires, semi structured interviews, lesson observations and examination of pupils’ written exercises. The questionnaire was completed by twenty two teachers. Semi-structured interviews were held with six teachers from the selected schools, while nine lesson observations were done and eighty exercise books were scrutinized for the presence of written Corrective Feedback. Results obtained showed that teachers’ stated beliefs about corrective feedback were not always demonstrated in their classroom practices. Furthermore the study revealed that oral Corrective Feedback was not used consistently in addition to a lack of uniformity in both the usage and interpretation of written Corrective Feedback. Results obtained showed that teachers’ stated beliefs about Corrective Feedback were not always demonstrated in their classroom practices. In addition, the study also revealed that some teachers were not aware of the codes used in written Corrective Feedback and their meaning. The conclusion reached in this study was that vi there is need for a more informed and consistent usage of Corrective Feedback among teachers. In the light of this finding, a Corrective Feedback model was suggested to assist teachers apply Corrective Feedback more consistently and more productively. A number of recommendations were made at the conclusion of this study. Firstly, it was recommended that marking codes be availed to teachers and pupils before the beginning of the school calendar. The contents of the advisory chart included in this study could be given to pupils to copy onto the back of their exercise books to enable them to interpret the feedback which the teachers would have written. It was recommended that teachers familiarise themselves with the developments in the use of CF in the ESL classroom. At school level this could be done through staff development workshop, where teachers share experiences about what works and what does not work in the ESL classroom. This should be done in view of the existing problem of communicative incompetency bedevilling pupils nationally. Secondly it was recommended that teachers familiarise themselves with the developments in the use of CF in the ESL classroom. The final recommendation was that teachers adopt minimal marking in the form of codes in order to cut down on turnaround time as well as stimulate individual learner automatisation of knowledge.
- Full Text:
- Date Issued: 2019
Teachers’ engagement with learners in inclusive foundation phase classrooms: a case study analysis
- Authors: Skae, Vera Astrid
- Date: 2019
- Subjects: Early childhood education -- South Africa -- Eastern Cape -- Case studies , Education and state -- South Africa
- Language: English
- Type: text , Thesis , Masters , MEd
- Identifier: http://hdl.handle.net/10962/92705 , vital:30722
- Description: Since 2001, South African teachers have been attempting to practise inclusive education in classrooms in ordinary, public schools. Previous research has shown the many challenges South African teachers face in our current educational environment. Strong arguments, however, have been made for more research to be done on actual teacher engagement with learners in our ordinary, public school classrooms, and the extent to which classroom practices are inclusive (Engelbrecht, Nel, Nel & Tlale, 2015, p. 3). This study sought to do an in-depth critical analysis of three foundation phase teachers and their engagement with learners in their classrooms at an Eastern Cape school. The aim was to examine how inclusive education was being enacted by the teacher with learners in real classroom settings, with particular attention paid to ways in which learners experience barriers to learning. A micro-level analysis was conducted in a single unit case study and using a qualitative research approach in an interpretive paradigm. Questionnaires, observations, and semi-structured interviews were conducted in an attempt to gather in-depth data. It was heartening to observe the extent to which inclusive education and practices were being enacted at the school and in the classrooms, and instructive in providing examples of what can work in the South African context. Key findings of this study include the generation of a framework for analysing inclusive classroom practice at the micro level. Criteria were identified as indicators of inclusive education of learners including those experiencing barriers to learning in the classroom. This study builds on and extends what has been developed at the macro and micro level of inclusive education in schools and in the classroom. It found that a number of challenges remain for enabling the implementation of an inclusive education. At the macro level, these include the provision of clear directives for implementation of inclusive education by the appropriate authorities; the provision of well-structured professional teacher training and development programmes in inclusive classroom practices, as well as in barriers to learning and how to address them; and the provision of funding for school and classroom infrastructure and resources. At the micro level, these include the successful implementation by teachers of inclusive classroom practices and the provision of the necessary support for learners experiencing barriers to learning in their classrooms, including expert personnel, resources, and assistive devices.
- Full Text:
- Date Issued: 2019
- Authors: Skae, Vera Astrid
- Date: 2019
- Subjects: Early childhood education -- South Africa -- Eastern Cape -- Case studies , Education and state -- South Africa
- Language: English
- Type: text , Thesis , Masters , MEd
- Identifier: http://hdl.handle.net/10962/92705 , vital:30722
- Description: Since 2001, South African teachers have been attempting to practise inclusive education in classrooms in ordinary, public schools. Previous research has shown the many challenges South African teachers face in our current educational environment. Strong arguments, however, have been made for more research to be done on actual teacher engagement with learners in our ordinary, public school classrooms, and the extent to which classroom practices are inclusive (Engelbrecht, Nel, Nel & Tlale, 2015, p. 3). This study sought to do an in-depth critical analysis of three foundation phase teachers and their engagement with learners in their classrooms at an Eastern Cape school. The aim was to examine how inclusive education was being enacted by the teacher with learners in real classroom settings, with particular attention paid to ways in which learners experience barriers to learning. A micro-level analysis was conducted in a single unit case study and using a qualitative research approach in an interpretive paradigm. Questionnaires, observations, and semi-structured interviews were conducted in an attempt to gather in-depth data. It was heartening to observe the extent to which inclusive education and practices were being enacted at the school and in the classrooms, and instructive in providing examples of what can work in the South African context. Key findings of this study include the generation of a framework for analysing inclusive classroom practice at the micro level. Criteria were identified as indicators of inclusive education of learners including those experiencing barriers to learning in the classroom. This study builds on and extends what has been developed at the macro and micro level of inclusive education in schools and in the classroom. It found that a number of challenges remain for enabling the implementation of an inclusive education. At the macro level, these include the provision of clear directives for implementation of inclusive education by the appropriate authorities; the provision of well-structured professional teacher training and development programmes in inclusive classroom practices, as well as in barriers to learning and how to address them; and the provision of funding for school and classroom infrastructure and resources. At the micro level, these include the successful implementation by teachers of inclusive classroom practices and the provision of the necessary support for learners experiencing barriers to learning in their classrooms, including expert personnel, resources, and assistive devices.
- Full Text:
- Date Issued: 2019
Teachers’ perception of the integration of environmental education into grade 12 curriculum in East London Education District
- Authors: Damoah, Benjamin
- Date: 2019
- Subjects: Environmental education
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: http://hdl.handle.net/10353/16528 , vital:40728
- Description: The study focuses on teachers’ perception of the integration of environmental education into grade 12 curriculum in East London education district. This study is based on empirical research. The theoretical framework of the study is based on Opportunity to Learn (OTL). The concept of OTL was formulated by international Association of Achievements (McDonnell, 1995).OTL is multiplicity of factors that create the conditions for teaching and learning, such as curricula, learning materials, facilities, teachers and instructional experiences. The research study is supported by national and international literatures based on environmental education and integration of environmental education as a component in the school curriculum, and policy documents. The study adopted qualitative research approach, using phenomenological method and interpretivism paradigm respectively. The empirical data was collected from one high school in Mdantsane Township in East London education district. The study sample consisted of 6 high school teachers. Data was collected through semi- structured interviews. According to the findings of the research, grade 12 teachers expressed disparities in their perceptions of environmental education as an integrated component into their subjects. Most of the subject teachers focused on the aspect of knowledge acquisition. According to South African education system, environmental education (EE) has been integrated into all subjects. Although there is environmental education in the GET and FET phase curriculum respectively, however it is not integrated evenly in all subjects. Some subjects like Life sciences, geography have more environmental content than other subjects. Teachers suggested that the approach adopted to integrate environmental education into the school curriculum was not favourable because teachers claimed that what is to be taught as environmental education in the various subjects is not indicated explicitly in the CAPS document. The CAPS document prescribes EE integration into all subjects which makes the teaching of EE a collective responsibility. The main actors of EE integration implementation are themselves a constraint to the success of the integration. The teacher is confronted with many challenges in the process of environmental education integration. This includes lack of teaching and learning resources, time and large class size. The role of teachers in the implementation of environmental education in developing an environmentally literate citizenry is of great significance. The responsibility of the government in ii developing a curriculum with clear goals and content, developing teachers’ capacity in the teaching of environmental education and provision of teaching and learning materials needs to be taken seriously by the government in educational plans and programs. Topics for future research on the integration of EE into grade 12 curriculums were suggested in order to improve on teaching and learning of environmental education
- Full Text:
- Date Issued: 2019
- Authors: Damoah, Benjamin
- Date: 2019
- Subjects: Environmental education
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: http://hdl.handle.net/10353/16528 , vital:40728
- Description: The study focuses on teachers’ perception of the integration of environmental education into grade 12 curriculum in East London education district. This study is based on empirical research. The theoretical framework of the study is based on Opportunity to Learn (OTL). The concept of OTL was formulated by international Association of Achievements (McDonnell, 1995).OTL is multiplicity of factors that create the conditions for teaching and learning, such as curricula, learning materials, facilities, teachers and instructional experiences. The research study is supported by national and international literatures based on environmental education and integration of environmental education as a component in the school curriculum, and policy documents. The study adopted qualitative research approach, using phenomenological method and interpretivism paradigm respectively. The empirical data was collected from one high school in Mdantsane Township in East London education district. The study sample consisted of 6 high school teachers. Data was collected through semi- structured interviews. According to the findings of the research, grade 12 teachers expressed disparities in their perceptions of environmental education as an integrated component into their subjects. Most of the subject teachers focused on the aspect of knowledge acquisition. According to South African education system, environmental education (EE) has been integrated into all subjects. Although there is environmental education in the GET and FET phase curriculum respectively, however it is not integrated evenly in all subjects. Some subjects like Life sciences, geography have more environmental content than other subjects. Teachers suggested that the approach adopted to integrate environmental education into the school curriculum was not favourable because teachers claimed that what is to be taught as environmental education in the various subjects is not indicated explicitly in the CAPS document. The CAPS document prescribes EE integration into all subjects which makes the teaching of EE a collective responsibility. The main actors of EE integration implementation are themselves a constraint to the success of the integration. The teacher is confronted with many challenges in the process of environmental education integration. This includes lack of teaching and learning resources, time and large class size. The role of teachers in the implementation of environmental education in developing an environmentally literate citizenry is of great significance. The responsibility of the government in ii developing a curriculum with clear goals and content, developing teachers’ capacity in the teaching of environmental education and provision of teaching and learning materials needs to be taken seriously by the government in educational plans and programs. Topics for future research on the integration of EE into grade 12 curriculums were suggested in order to improve on teaching and learning of environmental education
- Full Text:
- Date Issued: 2019
Teachers’ views on grade 7 reading comprehension skills amongst English first additional language learners: a case study
- Authors: Ruiters, Benedictor
- Date: 2019
- Subjects: Reading comprehension English language -- Study and teaching -- Foreign speakers
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: http://hdl.handle.net/10353/16307 , vital:40707
- Description: The purpose of this study was to investigate the views of Teachers about reading comprehension skills in grade 7 English Additional Language classrooms in Buffalo City Metropolitan, Eastern Cape. Objectives are to instil the love for reading and enabling learners to successfully learn to read and attain their full potential. The researcher was interested in exploring broader trends in reading comprehension skills, with the intention of contributing possible strategies to address the literacy level in English First Additional Language. The study was framed as qualitative in inquiry; a face-to-face semi-structured interview was used to collect data. The participants comprised of 24 learners and 4 educators. The theoretical framework utilised was Lev Vygotsky’s (1979) constructivist theory to analyse data using a qualitative analysis approach. Different tools to verify data, which comprised of semi- structured interview of open-ended questions and document analysis to obtain data from English First Additional Language teachers in four primary schools in the Buffalo City Metropolitan District, were used. Findings indicate English First Additional Language learners are not proficient in the language of teaching and learning because in other public schools mother tongue is additive language, while in other schools it does not exist. The recommendation was that the Department of education needs to introduce a reading module for English First Additional teachers who need training in this area of learning. Another recommendation highlighted by teachers is the revisiting of child development theories that will help teachers have a better understanding about the learners and which strategies to utilise during reading.
- Full Text:
- Date Issued: 2019
- Authors: Ruiters, Benedictor
- Date: 2019
- Subjects: Reading comprehension English language -- Study and teaching -- Foreign speakers
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: http://hdl.handle.net/10353/16307 , vital:40707
- Description: The purpose of this study was to investigate the views of Teachers about reading comprehension skills in grade 7 English Additional Language classrooms in Buffalo City Metropolitan, Eastern Cape. Objectives are to instil the love for reading and enabling learners to successfully learn to read and attain their full potential. The researcher was interested in exploring broader trends in reading comprehension skills, with the intention of contributing possible strategies to address the literacy level in English First Additional Language. The study was framed as qualitative in inquiry; a face-to-face semi-structured interview was used to collect data. The participants comprised of 24 learners and 4 educators. The theoretical framework utilised was Lev Vygotsky’s (1979) constructivist theory to analyse data using a qualitative analysis approach. Different tools to verify data, which comprised of semi- structured interview of open-ended questions and document analysis to obtain data from English First Additional Language teachers in four primary schools in the Buffalo City Metropolitan District, were used. Findings indicate English First Additional Language learners are not proficient in the language of teaching and learning because in other public schools mother tongue is additive language, while in other schools it does not exist. The recommendation was that the Department of education needs to introduce a reading module for English First Additional teachers who need training in this area of learning. Another recommendation highlighted by teachers is the revisiting of child development theories that will help teachers have a better understanding about the learners and which strategies to utilise during reading.
- Full Text:
- Date Issued: 2019
Teachers’use of curriculum materials in Grade 3 Mathematics: A Case Study
- Authors: Whale, Susan Gaye
- Date: 2019
- Subjects: Mathematics -- Study and teaching (Primary) -- South Africa , Education -- curriculum innovation
- Language: English
- Type: Thesis , Doctoral , PHD
- Identifier: http://hdl.handle.net/10948/45591 , vital:38916
- Description: The study examines four curriculum documents with regards to curriculum facets, further interrogated through indicators for certain facets in order to ascertain whether the documents could be considered to be educative. Comparison is made with selected resources internationally. Observed episodes in four mathematics classes are interrogated with regards to teacher facets and concomitant indicators, to assess whether the tenets proposed in the written curriculum are translated into practice in the classrooms. The four Grade 3 teachers are interviewed about their views on the curriculum, their views on teaching and their views on their own agency in teaching mathematics. The teachers’ complete selected examples from a Mathematics Knowledge for Training (MKT) questionnaire and are engaged in conversations about iii their beliefs about mathematics and their confidence in both doing and teaching mathematics. The study identifies that the current CAPS curriculum documents focus on mathematical content almost exclusively and give minimal guidance concerning pedagogical content knowledge. The agency of teachers is not addressed. The study suggests a three-dimensional model of curriculum design that encompasses new educative curriculum materials; guidance on innovative teacher practices and direction towards new beliefs in teachers which could build agency and confidence. The concern that this study uncovers is that although the school and teachers were specifically chosen to minimise linguistic and social detractors, the intended curriculum does not appear to have been universally translated into
- Full Text:
- Date Issued: 2019
- Authors: Whale, Susan Gaye
- Date: 2019
- Subjects: Mathematics -- Study and teaching (Primary) -- South Africa , Education -- curriculum innovation
- Language: English
- Type: Thesis , Doctoral , PHD
- Identifier: http://hdl.handle.net/10948/45591 , vital:38916
- Description: The study examines four curriculum documents with regards to curriculum facets, further interrogated through indicators for certain facets in order to ascertain whether the documents could be considered to be educative. Comparison is made with selected resources internationally. Observed episodes in four mathematics classes are interrogated with regards to teacher facets and concomitant indicators, to assess whether the tenets proposed in the written curriculum are translated into practice in the classrooms. The four Grade 3 teachers are interviewed about their views on the curriculum, their views on teaching and their views on their own agency in teaching mathematics. The teachers’ complete selected examples from a Mathematics Knowledge for Training (MKT) questionnaire and are engaged in conversations about iii their beliefs about mathematics and their confidence in both doing and teaching mathematics. The study identifies that the current CAPS curriculum documents focus on mathematical content almost exclusively and give minimal guidance concerning pedagogical content knowledge. The agency of teachers is not addressed. The study suggests a three-dimensional model of curriculum design that encompasses new educative curriculum materials; guidance on innovative teacher practices and direction towards new beliefs in teachers which could build agency and confidence. The concern that this study uncovers is that although the school and teachers were specifically chosen to minimise linguistic and social detractors, the intended curriculum does not appear to have been universally translated into
- Full Text:
- Date Issued: 2019
Teaching NCS (CAPS) FET mathematics: a comparison between an offline techno-blended Model and a traditional approach
- Authors: Munemo, Noname
- Date: 2019
- Subjects: Mathematics -- Study and teaching (Secondary) , Mathematics -- Study and teaching (Higher) -- South Africa Blended learning Educational innovations
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: http://hdl.handle.net/10948/41614 , vital:36545
- Description: This research is a comparative research study that compares the way learning has taken place when selected mathematics topics were taught to two groups of Grade 11 Mathematics learners. An offline Techno-Blended Teaching and Learning Model was used for one group, while the other group was taught without the integration of technology. The cognitive and affective impact of the use of technology when an offline Techno-Blended T&L Model was followed, was compared to a corresponding impact of an approach where no technology was integrated during the teaching of the topics. The research study involved teachers and selected learners in the Mathematics classes from four different high schools selected from two urban districts in the Eastern Cape Province in South Africa. The curriculum topics that the research focused on were Euclidean Geometry and Trigonometry.
- Full Text:
- Date Issued: 2019
- Authors: Munemo, Noname
- Date: 2019
- Subjects: Mathematics -- Study and teaching (Secondary) , Mathematics -- Study and teaching (Higher) -- South Africa Blended learning Educational innovations
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: http://hdl.handle.net/10948/41614 , vital:36545
- Description: This research is a comparative research study that compares the way learning has taken place when selected mathematics topics were taught to two groups of Grade 11 Mathematics learners. An offline Techno-Blended Teaching and Learning Model was used for one group, while the other group was taught without the integration of technology. The cognitive and affective impact of the use of technology when an offline Techno-Blended T&L Model was followed, was compared to a corresponding impact of an approach where no technology was integrated during the teaching of the topics. The research study involved teachers and selected learners in the Mathematics classes from four different high schools selected from two urban districts in the Eastern Cape Province in South Africa. The curriculum topics that the research focused on were Euclidean Geometry and Trigonometry.
- Full Text:
- Date Issued: 2019
Temperature dependence of persistent luminescence in CaAl2O4: Eu2+, Nd3+ related to beta irradiation and optical excitation
- Kalita, Jitumani M, Chithambo, Makaiko L
- Authors: Kalita, Jitumani M , Chithambo, Makaiko L
- Date: 2019
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/105158 , vital:32470 , https://doi.org/10.1016/j.jlumin.2018.10.062
- Description: Mechanisms responsible for the emission of persistent luminescence in CaAl2O4:Eu2+,Nd3+ are typically studied following excitation by ultraviolet or visible light. In contrast, we have studied the persistent luminescence from this material after beta irradiation and optical excitation. These studies have been carried out at 25 °C as well as at various temperatures up to 100 °C. A thermoluminescence (TL) glow curve measured at 1 °C/s following beta irradiation showed a glow peak at 63 °C. On the other hand, a glow curve measured after 15 s of optical excitation by polychromatic white light shows a peak at 102 °C. The partial heating procedure reveals that each of the TL peaks consist of several overlapping components. The TL in each case was analysed for kinetic parameters. The initial rise analysis carried out on the rising edge of the overlapping components shows that the activation energy of the component peaks corresponding to beta irradiation is consistent at (0.59 ± 0.01) eV. In comparison, activation energies corresponding to optical excitation increases with the partial heating temperature from (0.71 ± 0.01) eV to (0.76 ± 0.01) eV. The activation energy of (0.59 ± 0.01) eV is ascribed to an oxygen vacancy whereas the range of activation energies between (0.71 ± 0.01) eV and (0.76 ± 0.01) eV is ascribed to the 4 f levels of the Nd dopant.
- Full Text: false
- Date Issued: 2019
- Authors: Kalita, Jitumani M , Chithambo, Makaiko L
- Date: 2019
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/105158 , vital:32470 , https://doi.org/10.1016/j.jlumin.2018.10.062
- Description: Mechanisms responsible for the emission of persistent luminescence in CaAl2O4:Eu2+,Nd3+ are typically studied following excitation by ultraviolet or visible light. In contrast, we have studied the persistent luminescence from this material after beta irradiation and optical excitation. These studies have been carried out at 25 °C as well as at various temperatures up to 100 °C. A thermoluminescence (TL) glow curve measured at 1 °C/s following beta irradiation showed a glow peak at 63 °C. On the other hand, a glow curve measured after 15 s of optical excitation by polychromatic white light shows a peak at 102 °C. The partial heating procedure reveals that each of the TL peaks consist of several overlapping components. The TL in each case was analysed for kinetic parameters. The initial rise analysis carried out on the rising edge of the overlapping components shows that the activation energy of the component peaks corresponding to beta irradiation is consistent at (0.59 ± 0.01) eV. In comparison, activation energies corresponding to optical excitation increases with the partial heating temperature from (0.71 ± 0.01) eV to (0.76 ± 0.01) eV. The activation energy of (0.59 ± 0.01) eV is ascribed to an oxygen vacancy whereas the range of activation energies between (0.71 ± 0.01) eV and (0.76 ± 0.01) eV is ascribed to the 4 f levels of the Nd dopant.
- Full Text: false
- Date Issued: 2019
Template ecological analsyis of the narratives of partner’s and family member’s of women who consumed alcohol in pregnancy
- Authors: Tsetse, Agrinette Nontozamo
- Date: 2019
- Subjects: Pregnant women -- Alcohol use -- Social aspects , Substance abuse in pregnancy , Fetus -- Effect of drugs on , Pregnancy -- Psychological aspects , Pregnant women -- Substance use , Substance abuse -- Social aspects , Ecological Systems Theory
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/114905 , vital:34055
- Description: Although there is increasing research on alcohol in South Africa, most of this work has an epidemiological focus. Very little research has explored alcohol use during pregnancy specifically from the perspective of the woman’s partner or family member or focused on contextual risk factors beyond the pregnant woman. This information is important to ensure that interventions are formulated based on the social contexts within which drinking in pregnancy takes place and in guiding interventions that aim to prevent prenatal alcohol use, thereby preventing the occurrence of FASDs. This study was guided by Bronfenbrenner’s Ecological Systems Theory to understand partners’ and family members’ perspectives of prenatal exposure within the actual environments in which alcohol use takes place. According to this theory, an individual exists within layers of social relationships: the family, intimate partners, friendships, and healthcare workers (microsystems), interactions among these microsystems, for example, interaction between healthcare workers and intimate partner and family and social workers (mesosystem), accessibility of alcohol in the neighbourhoods (exosystems), religion, culture and society (macro-systems) and changes of the individual and socio-historical context (chronosystem). The data were collected using a biographic narrative interpretive method of interviewing. Thirteen narratives interviews were conducted with partners and family members in a disadvantaged community in Buffalo City, Eastern Cape Province. The interviews were analysed using Template Analysis within the Ecological Systems Theory to interrogate the stories of partners and family members. According to participants, some of the reasons women consumed alcohol in pregnancy are: drinking habits before pregnancy that were difficult to break in pregnancy; women drank during the first trimester of their pregnancy because of unplanned pregnancy; women continued drinking throughout their pregnancies to cope with the emotional upset caused by the trauma of rape and losing loved ones, stress, receiving HIV-diagnosis in pregnancy, intimate partner violence, infidelity, rejection and denial of pregnancy from partners. After birth, some women continued drinking. Consequently, their children were taken away from them by social workers and family members because the parents were unable to care for the child due to alcohol use. There was lack of compliance of shebeens with liquor regulations, heavy drinking, high rates of alcohol use in pregnancy, and easy accessibility of alcohol within this study community. Pregnant women used religious coping beliefs to cope with their circumstances such as changes in their health, relationships and finances. Drinking during pregnancy is a complex problem that stems from multiple social and structural issues and interventions should therefore not only focus on the individual, but also on social networks and communities.
- Full Text:
- Date Issued: 2019
- Authors: Tsetse, Agrinette Nontozamo
- Date: 2019
- Subjects: Pregnant women -- Alcohol use -- Social aspects , Substance abuse in pregnancy , Fetus -- Effect of drugs on , Pregnancy -- Psychological aspects , Pregnant women -- Substance use , Substance abuse -- Social aspects , Ecological Systems Theory
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/114905 , vital:34055
- Description: Although there is increasing research on alcohol in South Africa, most of this work has an epidemiological focus. Very little research has explored alcohol use during pregnancy specifically from the perspective of the woman’s partner or family member or focused on contextual risk factors beyond the pregnant woman. This information is important to ensure that interventions are formulated based on the social contexts within which drinking in pregnancy takes place and in guiding interventions that aim to prevent prenatal alcohol use, thereby preventing the occurrence of FASDs. This study was guided by Bronfenbrenner’s Ecological Systems Theory to understand partners’ and family members’ perspectives of prenatal exposure within the actual environments in which alcohol use takes place. According to this theory, an individual exists within layers of social relationships: the family, intimate partners, friendships, and healthcare workers (microsystems), interactions among these microsystems, for example, interaction between healthcare workers and intimate partner and family and social workers (mesosystem), accessibility of alcohol in the neighbourhoods (exosystems), religion, culture and society (macro-systems) and changes of the individual and socio-historical context (chronosystem). The data were collected using a biographic narrative interpretive method of interviewing. Thirteen narratives interviews were conducted with partners and family members in a disadvantaged community in Buffalo City, Eastern Cape Province. The interviews were analysed using Template Analysis within the Ecological Systems Theory to interrogate the stories of partners and family members. According to participants, some of the reasons women consumed alcohol in pregnancy are: drinking habits before pregnancy that were difficult to break in pregnancy; women drank during the first trimester of their pregnancy because of unplanned pregnancy; women continued drinking throughout their pregnancies to cope with the emotional upset caused by the trauma of rape and losing loved ones, stress, receiving HIV-diagnosis in pregnancy, intimate partner violence, infidelity, rejection and denial of pregnancy from partners. After birth, some women continued drinking. Consequently, their children were taken away from them by social workers and family members because the parents were unable to care for the child due to alcohol use. There was lack of compliance of shebeens with liquor regulations, heavy drinking, high rates of alcohol use in pregnancy, and easy accessibility of alcohol within this study community. Pregnant women used religious coping beliefs to cope with their circumstances such as changes in their health, relationships and finances. Drinking during pregnancy is a complex problem that stems from multiple social and structural issues and interventions should therefore not only focus on the individual, but also on social networks and communities.
- Full Text:
- Date Issued: 2019
Terrestrial alien ferns (Polypodiophyta): a global assessment of traits associated with invasiveness and their distribution and status in South Africa
- Authors: Jones, Emily Joy
- Date: 2019
- Subjects: Biodiversity -- South Africa , Alien plants -- South Africa , Botany -- South Africa , Plant ecology -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/39995 , vital:35643
- Description: Globally, invasive alien plants (IAPs) are one of the greatest threats to biodiversity, ecosystems and ecosystem services. The threats posed by IAPs have prompted inventory compilations and screening exercises which aim to understand why some taxa become invasive and others do not. Ferns are a diverse taxon that appear to have a high invasive potential, however ferns have been vastly understudied in the field of invasion biology. This study aimed to establish a basic understanding of terrestrial alien true ferns (Polypodiophyta, hereafter ‘alien ferns’) at both global and national (South African) scales. We developed a global inventory of alien ferns comprising 157 species using published literature and online inventories. Our global inventory indicated that there are significantly more alien fern species than previously estimated (60 species). We used generalised linear models with binomial response variables to determine which traits influenced the probability that an alien fern would become naturalised or invasive. Our models explained 30-40 % of the variance associated with invasiveness and showed that ground-dwelling life forms, reproductive plasticity, tolerance to disturbances and varied light conditions, and a broad introduced range (interpreted as high environmental tolerance and popularity in horticulture) were important determinants of invasiveness in alien ferns. Ultimately, we found that the probability of alien ferns becoming naturalised or invasive is more than 50 %. We further established which geographic regions and fern families had the highest incidences of alien ferns and identified species that were invasive over extensive introduced ranges. For the national scale study, we aimed to assess the distribution, abundance, invasion status, and habitat associations of terrestrial alien fern species present outside of cultivation in South Africa. Field surveys were conducted across the country in habitats suitable for ferns, guided by pre-existing records of alien fern occurrences. Thirteen species occurred outside of cultivation, all of which were classified as invasive, and among these, approximately 5000 plants were recorded across 300 localities. Species richness and abundance peaked along the Indian Ocean Coastal Belt and the Afro-montane phytogeographical regions. A multiple correspondence analysis revealed that alien ferns in South Africa were most strongly associated with indigenous forest habitats and the majority of species selected for shaded conditions, close to water. Only two species were closely associated with open habitats under high light conditions, with plantations also infrequently selected by alien ferns. Habitat generalists were closely associated with disturbance, but avoided open habitats, far from water. Compared to the most prominent angiosperm invaders in South Africa, alien ferns have a lower potential for widespread ii invasion and range expansion, probably due to their habitat specificity. We identified four species as potential targets for eradication and which should be listed as Category 1a under the Alien and Invasive Species regulations of the National Environmental Management: Biodiversity Act of South Africa. The remaining species should be listed as Category 1b since they occupied an extensive geographic range. The most prominent ferns included Adiantum raddianum, Sphaeropteris cooperi, Deparia japonica and Cyrtomium falcatum. Our study informed appropriate regulation for several species of alien ferns that were deemed to be data deficient and in need of assessment by a recent report on the status of biological invasions in South Africa. A risk analysis completed for S. cooperi confirmed that the species has a high invasion risk in South Africa and should be listed as Category 1b. Given that the outcomes of the risk analysis completed for S. cooperi matched the findings from our field surveys, this study supported risk analysis as a reliable (literature-based) method to evaluate IAPs. The findings of our assessments at the global and national scale corresponded in that various traits that promoted invasiveness in alien ferns globally were also facilitating invasion in South Africa. Additionally, of the eleven species found to be invasive over extensive introduced ranges at global scale, only two (Lygodium microphyllum and Angiopteris evecta) were not yet recorded in South Africa. Since horticulture was established as the primary pathway for the introduction of alien ferns, the management of alien ferns (globally and in South Africa) should focus on regulating trade. The sources of cultivation and the pathways of dissemination across the globe also need consideration. Basic environmental and biological associations of alien ferns were evident in this study, but to fully understand their invasive potential further research should focus on niche-based modelling to predict potential invasion ranges, the effects of biological traits on invasiveness, and the potential ecological impacts of these species.
- Full Text:
- Date Issued: 2019
- Authors: Jones, Emily Joy
- Date: 2019
- Subjects: Biodiversity -- South Africa , Alien plants -- South Africa , Botany -- South Africa , Plant ecology -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/39995 , vital:35643
- Description: Globally, invasive alien plants (IAPs) are one of the greatest threats to biodiversity, ecosystems and ecosystem services. The threats posed by IAPs have prompted inventory compilations and screening exercises which aim to understand why some taxa become invasive and others do not. Ferns are a diverse taxon that appear to have a high invasive potential, however ferns have been vastly understudied in the field of invasion biology. This study aimed to establish a basic understanding of terrestrial alien true ferns (Polypodiophyta, hereafter ‘alien ferns’) at both global and national (South African) scales. We developed a global inventory of alien ferns comprising 157 species using published literature and online inventories. Our global inventory indicated that there are significantly more alien fern species than previously estimated (60 species). We used generalised linear models with binomial response variables to determine which traits influenced the probability that an alien fern would become naturalised or invasive. Our models explained 30-40 % of the variance associated with invasiveness and showed that ground-dwelling life forms, reproductive plasticity, tolerance to disturbances and varied light conditions, and a broad introduced range (interpreted as high environmental tolerance and popularity in horticulture) were important determinants of invasiveness in alien ferns. Ultimately, we found that the probability of alien ferns becoming naturalised or invasive is more than 50 %. We further established which geographic regions and fern families had the highest incidences of alien ferns and identified species that were invasive over extensive introduced ranges. For the national scale study, we aimed to assess the distribution, abundance, invasion status, and habitat associations of terrestrial alien fern species present outside of cultivation in South Africa. Field surveys were conducted across the country in habitats suitable for ferns, guided by pre-existing records of alien fern occurrences. Thirteen species occurred outside of cultivation, all of which were classified as invasive, and among these, approximately 5000 plants were recorded across 300 localities. Species richness and abundance peaked along the Indian Ocean Coastal Belt and the Afro-montane phytogeographical regions. A multiple correspondence analysis revealed that alien ferns in South Africa were most strongly associated with indigenous forest habitats and the majority of species selected for shaded conditions, close to water. Only two species were closely associated with open habitats under high light conditions, with plantations also infrequently selected by alien ferns. Habitat generalists were closely associated with disturbance, but avoided open habitats, far from water. Compared to the most prominent angiosperm invaders in South Africa, alien ferns have a lower potential for widespread ii invasion and range expansion, probably due to their habitat specificity. We identified four species as potential targets for eradication and which should be listed as Category 1a under the Alien and Invasive Species regulations of the National Environmental Management: Biodiversity Act of South Africa. The remaining species should be listed as Category 1b since they occupied an extensive geographic range. The most prominent ferns included Adiantum raddianum, Sphaeropteris cooperi, Deparia japonica and Cyrtomium falcatum. Our study informed appropriate regulation for several species of alien ferns that were deemed to be data deficient and in need of assessment by a recent report on the status of biological invasions in South Africa. A risk analysis completed for S. cooperi confirmed that the species has a high invasion risk in South Africa and should be listed as Category 1b. Given that the outcomes of the risk analysis completed for S. cooperi matched the findings from our field surveys, this study supported risk analysis as a reliable (literature-based) method to evaluate IAPs. The findings of our assessments at the global and national scale corresponded in that various traits that promoted invasiveness in alien ferns globally were also facilitating invasion in South Africa. Additionally, of the eleven species found to be invasive over extensive introduced ranges at global scale, only two (Lygodium microphyllum and Angiopteris evecta) were not yet recorded in South Africa. Since horticulture was established as the primary pathway for the introduction of alien ferns, the management of alien ferns (globally and in South Africa) should focus on regulating trade. The sources of cultivation and the pathways of dissemination across the globe also need consideration. Basic environmental and biological associations of alien ferns were evident in this study, but to fully understand their invasive potential further research should focus on niche-based modelling to predict potential invasion ranges, the effects of biological traits on invasiveness, and the potential ecological impacts of these species.
- Full Text:
- Date Issued: 2019
Testing potential groundwater reservoir connectivity using isotopes in the south-central Karoo region
- Authors: Dlakavu, Sinazo
- Date: 2019
- Subjects: Groundwater -- South Africa -- Karoo , Hydrogeology -- South Africa Water-supply -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/39447 , vital:35248
- Description: Documenting areas with natural groundwater reservior connectivity using isotopes before the anticipated shale gas development in the Karoo Basin of South Africa could contribute to developing legislative framework for hydraulic fracturing. In this study, groundwater dynamics (primarily connectivity between old/deep and low temperature modern/shallow (<25°C) groundwater) are studied using isotopes (14C, δ18O-δ2H, 3H, and δ13C) in conjunction with geochemical parameters (sampling depth (masl) and (mbgl), temperature (°C), Electrical Conductivity (EC) (μS/m) and sustainable yield (l/s)). Previous groundwater studies conducted in the Karoo Basin suggest that 14C (pMC) has the least overlap among isotope signature constraints between the different aquifer/groundwater groups. The outcomes of 14C analysis for this study suggest that one groundwater sample is an old/deep groundwater sample (<53 pMC), and that three groundwater samples are composed of shallow/young groundwater mixed with old/deep groundwater (<74 pMC). These four relatively older samples have calculated 14C ages ≥ 1700 years and were collected from boreholes that are north-east of the Cape Mountains (~50 km). The position of these samples suggests that deep-seated faults within the Cape Mountains and the basement of the southern Karoo Basin act as preferential pathways for deep groundwater migration (as is consistent with existing deep geophysical data) to shallower depths (<60 mbgl) where it cools and/or mixes with low temperature groundwater (<25°C). Three more groundwater samples were found to match the relatively old calculated 14C ages (≥ 1700 years) of the groundwater samples collected close to the Cape Mountains even though they have modern 14C (pMC) concentrations (>74 pMC). This implies that adjusting the 14C content in Dissolved Inorganic Carbon (DIC) based on its dilution by 14C free carbonates is influential in controlling the mixed groundwater ages, and that relatively older groundwater occurs at shallow depths in other parts of the study area possibly due to linked fault systems between deep and shallow aquifers. δ18O-δ2H relationships for the sampled groundwater suggest that groundwater samples collected within the main drainage of the Great Fish River plot close to the Global Meteoric Water Line (GMWL) indicating that the recharge water to this groundwater does not experience significant evaporation. The average isotope composition of the recharging water for the all of the sampled groundwater is -7.90 ‰ and -46.72 ‰ for δ18O and δ2H, respectively. This result plots halfway between rainwater 18O-2H relationship lines for the Indian Ocean and the Atlantic Ocean. This suggests that the rainwater from which the sampled groundwater was derived from evolved from both the Indian and Atlantic Ocean waters.
- Full Text:
- Date Issued: 2019
- Authors: Dlakavu, Sinazo
- Date: 2019
- Subjects: Groundwater -- South Africa -- Karoo , Hydrogeology -- South Africa Water-supply -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/39447 , vital:35248
- Description: Documenting areas with natural groundwater reservior connectivity using isotopes before the anticipated shale gas development in the Karoo Basin of South Africa could contribute to developing legislative framework for hydraulic fracturing. In this study, groundwater dynamics (primarily connectivity between old/deep and low temperature modern/shallow (<25°C) groundwater) are studied using isotopes (14C, δ18O-δ2H, 3H, and δ13C) in conjunction with geochemical parameters (sampling depth (masl) and (mbgl), temperature (°C), Electrical Conductivity (EC) (μS/m) and sustainable yield (l/s)). Previous groundwater studies conducted in the Karoo Basin suggest that 14C (pMC) has the least overlap among isotope signature constraints between the different aquifer/groundwater groups. The outcomes of 14C analysis for this study suggest that one groundwater sample is an old/deep groundwater sample (<53 pMC), and that three groundwater samples are composed of shallow/young groundwater mixed with old/deep groundwater (<74 pMC). These four relatively older samples have calculated 14C ages ≥ 1700 years and were collected from boreholes that are north-east of the Cape Mountains (~50 km). The position of these samples suggests that deep-seated faults within the Cape Mountains and the basement of the southern Karoo Basin act as preferential pathways for deep groundwater migration (as is consistent with existing deep geophysical data) to shallower depths (<60 mbgl) where it cools and/or mixes with low temperature groundwater (<25°C). Three more groundwater samples were found to match the relatively old calculated 14C ages (≥ 1700 years) of the groundwater samples collected close to the Cape Mountains even though they have modern 14C (pMC) concentrations (>74 pMC). This implies that adjusting the 14C content in Dissolved Inorganic Carbon (DIC) based on its dilution by 14C free carbonates is influential in controlling the mixed groundwater ages, and that relatively older groundwater occurs at shallow depths in other parts of the study area possibly due to linked fault systems between deep and shallow aquifers. δ18O-δ2H relationships for the sampled groundwater suggest that groundwater samples collected within the main drainage of the Great Fish River plot close to the Global Meteoric Water Line (GMWL) indicating that the recharge water to this groundwater does not experience significant evaporation. The average isotope composition of the recharging water for the all of the sampled groundwater is -7.90 ‰ and -46.72 ‰ for δ18O and δ2H, respectively. This result plots halfway between rainwater 18O-2H relationship lines for the Indian Ocean and the Atlantic Ocean. This suggests that the rainwater from which the sampled groundwater was derived from evolved from both the Indian and Atlantic Ocean waters.
- Full Text:
- Date Issued: 2019
Testing the efficient market hypothesis in the cryptocurrency market
- Authors: Apopo, Natalya Camilla
- Date: 2019
- Subjects: Digital currency
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: http://hdl.handle.net/10948/42427 , vital:36662
- Description: Digital currencies are rising in popularity owing to their purported benefits and the speculative profits that investors are making in the market. These currencies, though decentralised in substance, can be purchased using digital wallets from cryptocurrency exchange platforms around the world. In Africa, these platforms are still at the nascent stages of growth and development, but evidence suggests a burgeoning potential in these markets. Volatility in these markets has been a topic of concern for many empirical investigations with most finding corroborative evidence of excess volatility in the digital currency market. However, there is a conflicting body of evidence when it comes to the studies evaluating the efficiency of the virtual currency market. The efficient market hypothesis ( EMH)is a controversial theory in finance. Proponents argue that it provides a basis for understanding financial markets whereas opponents suggest that the hypothesis is premature in its assumptions of the real functioning of these markets. Though not perfect, the efficient markets model provides a sufficient baseline against which capital markets may be analysed. Besides being one of the most empirically investigated theories in finance, its utility led to the development of later models such as the capital asset pricing model. In postulating that the prices of securities reflect all available information in capital markets, the efficient markets theory lends itself to testing the efficacy levels of the cryptocurrency market. For the purposes of this study, the weak version of the efficient markets theory was evaluated as itis considered the lowest possible form of efficiency attainable. Using both linear and nonlinear unit root testing methodologies, a significant subset of the cryptocurrency market was investigated for inefficiencies via the null hypothesis of non-stationarity. There were mixed results from the testing process, but a substantial portion of the currencies investigated rejected the null of a unit root in favour of stationarity, providing some evidence against weak form efficiency. For these reasons, it is recommended that further research be conducted in the virtual currency markets to offer more conclusive findings.
- Full Text:
- Date Issued: 2019
- Authors: Apopo, Natalya Camilla
- Date: 2019
- Subjects: Digital currency
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: http://hdl.handle.net/10948/42427 , vital:36662
- Description: Digital currencies are rising in popularity owing to their purported benefits and the speculative profits that investors are making in the market. These currencies, though decentralised in substance, can be purchased using digital wallets from cryptocurrency exchange platforms around the world. In Africa, these platforms are still at the nascent stages of growth and development, but evidence suggests a burgeoning potential in these markets. Volatility in these markets has been a topic of concern for many empirical investigations with most finding corroborative evidence of excess volatility in the digital currency market. However, there is a conflicting body of evidence when it comes to the studies evaluating the efficiency of the virtual currency market. The efficient market hypothesis ( EMH)is a controversial theory in finance. Proponents argue that it provides a basis for understanding financial markets whereas opponents suggest that the hypothesis is premature in its assumptions of the real functioning of these markets. Though not perfect, the efficient markets model provides a sufficient baseline against which capital markets may be analysed. Besides being one of the most empirically investigated theories in finance, its utility led to the development of later models such as the capital asset pricing model. In postulating that the prices of securities reflect all available information in capital markets, the efficient markets theory lends itself to testing the efficacy levels of the cryptocurrency market. For the purposes of this study, the weak version of the efficient markets theory was evaluated as itis considered the lowest possible form of efficiency attainable. Using both linear and nonlinear unit root testing methodologies, a significant subset of the cryptocurrency market was investigated for inefficiencies via the null hypothesis of non-stationarity. There were mixed results from the testing process, but a substantial portion of the currencies investigated rejected the null of a unit root in favour of stationarity, providing some evidence against weak form efficiency. For these reasons, it is recommended that further research be conducted in the virtual currency markets to offer more conclusive findings.
- Full Text:
- Date Issued: 2019
Testing the thermal limits of Eccritotarsus catarinensis: a case of thermal plasticity
- Porter, Jordan D, Owen, Candice A, Compton, Stephen G, Coetzee, Julie A
- Authors: Porter, Jordan D , Owen, Candice A , Compton, Stephen G , Coetzee, Julie A
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/417533 , vital:71461 , xlink:href="https://doi.org/10.1080/09583157.2019.1572712"
- Description: Water hyacinth is considered the most damaging aquatic weed in South Africa. The success of biocontrol initiatives against the weed varies nation-wide, but control remains generally unattainable in higher altitude, temperate regions. Eccritotarsus catarinensis (Hemiptera: Miridae) is a biocontrol agent of water hyacinth that was first released in South Africa in 1996. By 2011, it was established at over 30 sites across the country. These include the Kubusi River, a site with a temperate climate where agent establishment and persistence was unexpected. This study compared the critical thermal limits of the Kubusi River insect population with a laboratory-reared culture to determine whether any physiological plasticity was evident that could account for its unexpected establishment. There were no significant differences in critical thermal maxima (CTmax) or minima (CTmin) between sexes, while the effect of rate of temperature change on the thermal parameters in the experiments had a significant impact in some trials. Both CTmax and CTmin differed significantly between the two populations, with the field individuals tolerating significantly lower temperatures (CTmin: −0.3°C ± 0.063 [SE], CTmax: 42.8°C ± 0.155 [SE]) than those maintained in the laboratory (CTmin: 1.1°C ± 0.054 [SE], CTmax: 44.9°C ± 0.196 [SE]). Acclimation of each population to the environmental conditions typical of the other for a five-day period illustrated that short-term acclimation accounted for some, but not all of the variation between their lower thermal limits. This study provides evidence for the first cold-adapted strain of E. catarinensis in the field, with potential value for introduction into other colder regions where water hyacinth control is currently unattainable.
- Full Text:
- Date Issued: 2019
- Authors: Porter, Jordan D , Owen, Candice A , Compton, Stephen G , Coetzee, Julie A
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/417533 , vital:71461 , xlink:href="https://doi.org/10.1080/09583157.2019.1572712"
- Description: Water hyacinth is considered the most damaging aquatic weed in South Africa. The success of biocontrol initiatives against the weed varies nation-wide, but control remains generally unattainable in higher altitude, temperate regions. Eccritotarsus catarinensis (Hemiptera: Miridae) is a biocontrol agent of water hyacinth that was first released in South Africa in 1996. By 2011, it was established at over 30 sites across the country. These include the Kubusi River, a site with a temperate climate where agent establishment and persistence was unexpected. This study compared the critical thermal limits of the Kubusi River insect population with a laboratory-reared culture to determine whether any physiological plasticity was evident that could account for its unexpected establishment. There were no significant differences in critical thermal maxima (CTmax) or minima (CTmin) between sexes, while the effect of rate of temperature change on the thermal parameters in the experiments had a significant impact in some trials. Both CTmax and CTmin differed significantly between the two populations, with the field individuals tolerating significantly lower temperatures (CTmin: −0.3°C ± 0.063 [SE], CTmax: 42.8°C ± 0.155 [SE]) than those maintained in the laboratory (CTmin: 1.1°C ± 0.054 [SE], CTmax: 44.9°C ± 0.196 [SE]). Acclimation of each population to the environmental conditions typical of the other for a five-day period illustrated that short-term acclimation accounted for some, but not all of the variation between their lower thermal limits. This study provides evidence for the first cold-adapted strain of E. catarinensis in the field, with potential value for introduction into other colder regions where water hyacinth control is currently unattainable.
- Full Text:
- Date Issued: 2019