Implementation of strategies used to manage conflict between students and staff in secondary schools in Malawi : towards a comprehensive framework
- Authors: Zimpita, Valentino Tipitana
- Date: 2018
- Subjects: Conflict management Conflict management -- Study and teaching Violence -- Prevention
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/9412 , vital:34348
- Description: The study aimed at examining how strategies used to manage conflict between students and staff in secondary schools in Malawi were implemented. This was after it had been noted that conflicts in secondary schools in Malawi usually ended in violence. The study employed a pragmatic research paradigm. In this paradigm, a researcher employs mixed methods approach which collects both quantitative and qualitative data. Using a concurrent triangulation mixed method design, the two types of data were collected concurrently and analysed simultaneously. Study participants were head teachers, teachers, students, education officials and parents. Most of the teachers were randomly sampled while a few other teachers, the head teachers, the education officials and the parents were purposefully sampled. The study found that there were various causes of conflict in secondary schools in Malawi which included misunderstanding of human rights, poor communication between students and staff, poor school management by head teachers and lack of students‘ involvement in decisions that concerned them. The study further found that conflict was in a way beneficial to schools as it was a learning point for both students and staff. However, such benefits were overshadowed by the many evils that violence brought such as disturbing teaching and learning. The study also found that there were two approaches in the way schools managed conflict; engagement of students and calling for police intervention. It transpired that on the overall, stakeholders were aware of different conflict management skills but they did not know how best to use them. In addition, it transpired that stakeholders were not comfortable with win-win approaches to conflict management. This was against a background that the stakeholders were involved in conflict management in different ways. It also came out clear that support to secondary schools in the management of conflict was at two levels; school level and system level. On the part of monitoring, it transpired that the mechanism which were there were ad hoc and they included inspection visits and the requirement that head teachers should always submit reports which could carry issues related to conflict. The study concluded that poorly managed conflicts which turned into violence were a menace to secondary schools in Malawi. In this regard, there was need to ensure effective conflict management in order to avoid violence. To achieve this, the study has made a number of recommendations. Among them, it has been recommended that schools should from time to time take stork of the likely causes of conflict and address them accordingly. It has also been recommended that schools should put in place mechanisms for ensuring two way communication so that students feel free to air out their concerns. At Ministry level, it has been recommended that the MoEST should take guidance and counselling seriously by among other things training teacher councillors and making the post an established one. It has also been recommended that the MoEST should make sure that head teachers, deputy head teachers, teachers, parents and even education officials are inducted in conflict management.
- Full Text:
- Authors: Zimpita, Valentino Tipitana
- Date: 2018
- Subjects: Conflict management Conflict management -- Study and teaching Violence -- Prevention
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/9412 , vital:34348
- Description: The study aimed at examining how strategies used to manage conflict between students and staff in secondary schools in Malawi were implemented. This was after it had been noted that conflicts in secondary schools in Malawi usually ended in violence. The study employed a pragmatic research paradigm. In this paradigm, a researcher employs mixed methods approach which collects both quantitative and qualitative data. Using a concurrent triangulation mixed method design, the two types of data were collected concurrently and analysed simultaneously. Study participants were head teachers, teachers, students, education officials and parents. Most of the teachers were randomly sampled while a few other teachers, the head teachers, the education officials and the parents were purposefully sampled. The study found that there were various causes of conflict in secondary schools in Malawi which included misunderstanding of human rights, poor communication between students and staff, poor school management by head teachers and lack of students‘ involvement in decisions that concerned them. The study further found that conflict was in a way beneficial to schools as it was a learning point for both students and staff. However, such benefits were overshadowed by the many evils that violence brought such as disturbing teaching and learning. The study also found that there were two approaches in the way schools managed conflict; engagement of students and calling for police intervention. It transpired that on the overall, stakeholders were aware of different conflict management skills but they did not know how best to use them. In addition, it transpired that stakeholders were not comfortable with win-win approaches to conflict management. This was against a background that the stakeholders were involved in conflict management in different ways. It also came out clear that support to secondary schools in the management of conflict was at two levels; school level and system level. On the part of monitoring, it transpired that the mechanism which were there were ad hoc and they included inspection visits and the requirement that head teachers should always submit reports which could carry issues related to conflict. The study concluded that poorly managed conflicts which turned into violence were a menace to secondary schools in Malawi. In this regard, there was need to ensure effective conflict management in order to avoid violence. To achieve this, the study has made a number of recommendations. Among them, it has been recommended that schools should from time to time take stork of the likely causes of conflict and address them accordingly. It has also been recommended that schools should put in place mechanisms for ensuring two way communication so that students feel free to air out their concerns. At Ministry level, it has been recommended that the MoEST should take guidance and counselling seriously by among other things training teacher councillors and making the post an established one. It has also been recommended that the MoEST should make sure that head teachers, deputy head teachers, teachers, parents and even education officials are inducted in conflict management.
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Examining teachers' role in the promotion of child-friendly environments in Zimbabwean secondary schools : implications for teacher professional development
- Authors: Zendah, Ketiwe
- Date: 2017
- Subjects: Education, Secondary -- Zimbabwe Teachers -- Professional relationships School management and organization -- Zimbabwe
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/4937 , vital:28810
- Description: Hostile school environments are a cause of concern and a perennial international educational problem. The UNICEF’s Child-Friendly Schools (CFS) approach is an international intervention meant to safeguard learners against hostile school environments. The CFS approach mandates schools to offer learners environments and conditions that uphold children’s rights and enhance their development to full potential. The purpose of this mixed methods research study, employing a concurrent triangulation design, was to explore the role of teachers in the promotion of CFS environments. Holsti’s (1970) role theory formed the theoretical framework of this study. The research questions focused on teachers’ understanding of the CFS concept, support offered, strategies employed, challenges encountered, and the implications for teacher professional development. The data collection methods were questionnaires, in-depth interviews, and document analysis with school heads, teachers and learners in the seven government urban secondary schools in Mutare district of Manicaland province in Zimbabwe. Quantitative and qualitative data were independently analysed and merged at the interpretation stage through triangulation of results. Major findings reveal that teachers have poor understanding of the CFS concept, are offered moderate support, occasionally employ viable strategies, and are hindered by various factors in the process of promoting CFS environments. The study’s implications for teacher professional development are rooted in identifying sustainable approaches that adequately equip teachers with relevant information, skills and attitudes that ensure the promotion of CFS environments.
- Full Text:
- Authors: Zendah, Ketiwe
- Date: 2017
- Subjects: Education, Secondary -- Zimbabwe Teachers -- Professional relationships School management and organization -- Zimbabwe
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/4937 , vital:28810
- Description: Hostile school environments are a cause of concern and a perennial international educational problem. The UNICEF’s Child-Friendly Schools (CFS) approach is an international intervention meant to safeguard learners against hostile school environments. The CFS approach mandates schools to offer learners environments and conditions that uphold children’s rights and enhance their development to full potential. The purpose of this mixed methods research study, employing a concurrent triangulation design, was to explore the role of teachers in the promotion of CFS environments. Holsti’s (1970) role theory formed the theoretical framework of this study. The research questions focused on teachers’ understanding of the CFS concept, support offered, strategies employed, challenges encountered, and the implications for teacher professional development. The data collection methods were questionnaires, in-depth interviews, and document analysis with school heads, teachers and learners in the seven government urban secondary schools in Mutare district of Manicaland province in Zimbabwe. Quantitative and qualitative data were independently analysed and merged at the interpretation stage through triangulation of results. Major findings reveal that teachers have poor understanding of the CFS concept, are offered moderate support, occasionally employ viable strategies, and are hindered by various factors in the process of promoting CFS environments. The study’s implications for teacher professional development are rooted in identifying sustainable approaches that adequately equip teachers with relevant information, skills and attitudes that ensure the promotion of CFS environments.
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Spatial and seasonal distribution of selected persistent organic pollutants and phenolic derivatives along the course of the Buffalo River in the Eastern Cape Province of South Africa
- Authors: Yahaya, Abdulrazaq
- Date: 2017
- Subjects: Organic water pollutants Water -- Purification -- Organic compounds removal
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/5939 , vital:29448
- Description:
Persistent organic pollutants (POPs) fall under a group of synthetic chemicals known for their persistence in environmental matrices such as soil and water, and are used in industrial, domestic and agricultural applications. Because of their volatility and lipophilicity, POPs can be transported far away from their point sources and bio-accumulate in food and in fatty tissues of humans and animals. In view of their toxicity and carcinogenicity some organic pollutants such as polychlorinated biphenyl (PCBs), organochlorine pesticides (OCPs) and phenolic derivatives (chlorophenol and nitrophenol) have been classified by United State Environmental Protection Agency (USEPA) and World Health Organization (WHO) as priority pollutants. The present work evaluated the distribution patterns of 19 polychlorinated biphenyls congeners, 17 organochlorine pesticides and selected phenolic derivatives (USEPA 11-priority pollutants) in the Buffalo River, in the Eastern Cape Province, South Africa between December 2015 and May 2016. The Liquid-liquid extraction technique was used for PCBs, OCPs and phenolic derivatives in the river water samples. Silica gel and florisil clean up were carried out for PCBs and OCPs samples respectively and analyzed with gas chromatography electron capture detector (GC/ECD). Phenolic compounds were derivatized and analyzed by gas chromatography mass spectrometer (GC/MS). Limits of detection (LOD), limit of quantitation (LOQ) and relative standard deviation (RSD) for the PCBs were 10 to 330 ng/L, 20 to 1,060 ng/L and 1.18 to 14.1 percent respectively. The LOD, LOQ and RSD for the OCPs were from 20 - 60 ng/L, 110 - 530 ng/L and 0.02 - 0.06 percent, while the corresponding values for the phenolic derivatives were 10 to 70 ng/L, 33 to 222 ng/L and 1.99 - 10.86 percent. In summer, the concentrations of PCBs, OCPs and phenolic derivatives ranged from
- Full Text:
- Authors: Yahaya, Abdulrazaq
- Date: 2017
- Subjects: Organic water pollutants Water -- Purification -- Organic compounds removal
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/5939 , vital:29448
- Description:
Persistent organic pollutants (POPs) fall under a group of synthetic chemicals known for their persistence in environmental matrices such as soil and water, and are used in industrial, domestic and agricultural applications. Because of their volatility and lipophilicity, POPs can be transported far away from their point sources and bio-accumulate in food and in fatty tissues of humans and animals. In view of their toxicity and carcinogenicity some organic pollutants such as polychlorinated biphenyl (PCBs), organochlorine pesticides (OCPs) and phenolic derivatives (chlorophenol and nitrophenol) have been classified by United State Environmental Protection Agency (USEPA) and World Health Organization (WHO) as priority pollutants. The present work evaluated the distribution patterns of 19 polychlorinated biphenyls congeners, 17 organochlorine pesticides and selected phenolic derivatives (USEPA 11-priority pollutants) in the Buffalo River, in the Eastern Cape Province, South Africa between December 2015 and May 2016. The Liquid-liquid extraction technique was used for PCBs, OCPs and phenolic derivatives in the river water samples. Silica gel and florisil clean up were carried out for PCBs and OCPs samples respectively and analyzed with gas chromatography electron capture detector (GC/ECD). Phenolic compounds were derivatized and analyzed by gas chromatography mass spectrometer (GC/MS). Limits of detection (LOD), limit of quantitation (LOQ) and relative standard deviation (RSD) for the PCBs were 10 to 330 ng/L, 20 to 1,060 ng/L and 1.18 to 14.1 percent respectively. The LOD, LOQ and RSD for the OCPs were from 20 - 60 ng/L, 110 - 530 ng/L and 0.02 - 0.06 percent, while the corresponding values for the phenolic derivatives were 10 to 70 ng/L, 33 to 222 ng/L and 1.99 - 10.86 percent. In summer, the concentrations of PCBs, OCPs and phenolic derivatives ranged from
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Assessment of monitoring and evaluation of non-financial performance of provincial departments in the province of the Eastern Cape with special reference to its impact on service delivery
- Authors: Vermaak, Ernest Paul
- Date: 2016
- Subjects: Government productivity -- South Africa -- Eastern Cape -- Evaluation Performance standards -- South Africa -- Eastern Cape -- Evaluation Government accountability -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/4571 , vital:28423
- Description: In this research study an investigation was launched into the monitoring and evaluation system that the government introduced to monitor and evaluate the performance information produced by the Provincial Government Departments on the implementation of their annual performance plans. The Government Departments obtain budget approval from the Legislature and submit their three-year performance plans with their budgets. The government realized that service delivery was not improving against the back drop of annually increasing the budgets. The monitoring and evaluation system was introduced to assist the Government Departments with the implementation of their annual performance plans. Monitoring and evaluation serves as a control measure and deviations can be detected from the planned outputs of the Government Departments. Corrective measures must be instituted that will have the effect that the Government Departments meet the targets set in the indicators as approved in the annual performance plans. A literature review was conducted on monitoring and evaluation regarding the ideal manner in which it should be performed. The South African Government introduced a number of discussion documents from the Presidency and National Treasury on monitoring and evaluation. Several authors raised their views on the matter and it was captured in the research study. The methodology followed was based on the Systems Theory and a questionnaire was prepared and circulated amongst Political Office Bearers and Chief Officials in the Provincial Government Departments in the Eastern Cape on the issues that was researched. Interviews were conducted with selected participants to gain clarity on specific issues related to the questionnaire. The official annual report issued by the Auditor General to the Provincial Legislature served as official document in the research study. The data collected from the questionnaire, interviews and official documentation was analyzed and graphs were drawn and deductions were made from the results. Findings and recommendations were made from the data collected and a summary was compiled of the issues raised in the research study.
- Full Text:
- Authors: Vermaak, Ernest Paul
- Date: 2016
- Subjects: Government productivity -- South Africa -- Eastern Cape -- Evaluation Performance standards -- South Africa -- Eastern Cape -- Evaluation Government accountability -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/4571 , vital:28423
- Description: In this research study an investigation was launched into the monitoring and evaluation system that the government introduced to monitor and evaluate the performance information produced by the Provincial Government Departments on the implementation of their annual performance plans. The Government Departments obtain budget approval from the Legislature and submit their three-year performance plans with their budgets. The government realized that service delivery was not improving against the back drop of annually increasing the budgets. The monitoring and evaluation system was introduced to assist the Government Departments with the implementation of their annual performance plans. Monitoring and evaluation serves as a control measure and deviations can be detected from the planned outputs of the Government Departments. Corrective measures must be instituted that will have the effect that the Government Departments meet the targets set in the indicators as approved in the annual performance plans. A literature review was conducted on monitoring and evaluation regarding the ideal manner in which it should be performed. The South African Government introduced a number of discussion documents from the Presidency and National Treasury on monitoring and evaluation. Several authors raised their views on the matter and it was captured in the research study. The methodology followed was based on the Systems Theory and a questionnaire was prepared and circulated amongst Political Office Bearers and Chief Officials in the Provincial Government Departments in the Eastern Cape on the issues that was researched. Interviews were conducted with selected participants to gain clarity on specific issues related to the questionnaire. The official annual report issued by the Auditor General to the Provincial Legislature served as official document in the research study. The data collected from the questionnaire, interviews and official documentation was analyzed and graphs were drawn and deductions were made from the results. Findings and recommendations were made from the data collected and a summary was compiled of the issues raised in the research study.
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Laccase production by selected bacteria species isolated from some aquatic and terrestrial milieu of the Eastern Cape : applications in wastewater treatment
- Authors: Unuofin, John Onolame
- Date: 2018
- Subjects: Laccase Sewage -- Purification -- Biological treatment Water -- Purification
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/9626 , vital:34810
- Description: Aromatic pollutants are a diverse group of chemicals which are continuously produced from industrialization, urbanization and sophistication in technological advancement. Pristine water source polluted by these chemicls makes the water unsafe for human consumption, and as well disrupts the trophic structure of the aquatic milieu. Physico-chemical treatment techniques employed so far have been accompanied by major drawbacks which have overriden the relative successes recorded, hence, greener, simpler and more efficient methods of pollutant transformation is imperative. The prospect of enzymatic treatment of pollutants has gradually been receiving growing attention in contemporary times due to the their environmental friendliness and production economic feasiblity. Laccase, a multicopper oxidase has heightened its appeal towards environmental and biotechnological applications due to its broad substrate specificity and its requirement of atmospheric molecular oxygen as a cosubstrate and the discharge of water as the byproduct. Hence, this present study was designed to evaluate the biotechnological potentials of laccases produced by some bacteria species from some aquatic biomes of the Eastern Cape Province, South Africa. The laccase-producing bacteria were isolated from selected environmental samples by selective enrichment using selective aromatic compounds as sole carbon source and subsequently, laccase-screening phenolic substrates. The laccase-producing bacteria were identified by molecular techniques as proteobacteria belonging to the following genera: Achromobacter, Bordetella, Citrobacter, Pseudomonas and Stenotrophomonas. Optimisation of laccase production in a submerged fermentation was by traditional and statistical methods, where four isolates (Hb9c; Achromobacter xylosoxidans HWN16, Hb16c; Bordetella bronchisepta HSO16, Berl11b2; Stenotrophomonas maltophilia BIJ16, Ie1c; Citrobacter freundii LLJ16) were evaluated for the fermentative production of laccase from lignocellulosic agroindustrial residues. Predictions from statistical optimisation showed that weakly acidic conditions (pH 5) and low agitation speed (100 rpm) were required for maximum laccase production from mandarin peelings (0.5 g/200 mL) and NaNO3 (0.25 g/200 mL) in Hb9c, maize stover (0.50 g/200 mL) and NaNO3 (0.050 g/200mL) in Berl11b2 while a lower agitation speed (50 rpm) was required for maximum laccase output from 2.0 g/200 mL maize stover and 0.050 g/200 mL KNO3 in Ie1c. However, 2.50 g/200 mL wheat bran, 0.050 g/200 mL yeast extract and 50 rpm agitiation under acidic conditions (pH3) yielded maximum laccase titres in Hb16c. Further characterisation of Hb9c and Ie1c laccase secretions portrayed their polyextremotolerant capacities. They were active at a broad range of tempertaure (0-90 degreesC); with optima at 70°C (Hb9c) and 60°C (Ie1c), pH (3-11); with optima at pH 6 (Ie1c) and pH 8 (Hb9c), respectively, and were equally thermo- and pH-stable. Their activities were either improved or left unabated by high concentrations of cations, detergents, and chloride. In addition, catalytic activities of Hb9c and Ie1c laccase secretions increased when they were preincubated with 2 – 20 percent of fluoride, a potent inhibitor. Consequently, a molecular perspective depicted the isolates to have multiple homologous laccase encoding genes. The enzymes were successfully immobilised on solid supports comprising gelatin and Na-alginate with a recovery of cca. 85 percent residual activity after 8 cycles of oprertional stability experiments. The immobilised laccases were remarkable in the decolourisation of synthetic dyes, albeit, free forms also elicited satisfactory performances. Ultimately, the application of free laccases in denim bleaching, individually or with a blend of a mediator, ABTS, showed that denim colours could be bleached without the need for chemical bleaching agents. The results obtained suggest the bacteria laccases produced from lignocellulosic wastes may serve as potent degraders of phenolic pollutants in water and, may also contribute to the bioeconomy and promote greener techniques for industrial applications.
- Full Text:
- Authors: Unuofin, John Onolame
- Date: 2018
- Subjects: Laccase Sewage -- Purification -- Biological treatment Water -- Purification
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/9626 , vital:34810
- Description: Aromatic pollutants are a diverse group of chemicals which are continuously produced from industrialization, urbanization and sophistication in technological advancement. Pristine water source polluted by these chemicls makes the water unsafe for human consumption, and as well disrupts the trophic structure of the aquatic milieu. Physico-chemical treatment techniques employed so far have been accompanied by major drawbacks which have overriden the relative successes recorded, hence, greener, simpler and more efficient methods of pollutant transformation is imperative. The prospect of enzymatic treatment of pollutants has gradually been receiving growing attention in contemporary times due to the their environmental friendliness and production economic feasiblity. Laccase, a multicopper oxidase has heightened its appeal towards environmental and biotechnological applications due to its broad substrate specificity and its requirement of atmospheric molecular oxygen as a cosubstrate and the discharge of water as the byproduct. Hence, this present study was designed to evaluate the biotechnological potentials of laccases produced by some bacteria species from some aquatic biomes of the Eastern Cape Province, South Africa. The laccase-producing bacteria were isolated from selected environmental samples by selective enrichment using selective aromatic compounds as sole carbon source and subsequently, laccase-screening phenolic substrates. The laccase-producing bacteria were identified by molecular techniques as proteobacteria belonging to the following genera: Achromobacter, Bordetella, Citrobacter, Pseudomonas and Stenotrophomonas. Optimisation of laccase production in a submerged fermentation was by traditional and statistical methods, where four isolates (Hb9c; Achromobacter xylosoxidans HWN16, Hb16c; Bordetella bronchisepta HSO16, Berl11b2; Stenotrophomonas maltophilia BIJ16, Ie1c; Citrobacter freundii LLJ16) were evaluated for the fermentative production of laccase from lignocellulosic agroindustrial residues. Predictions from statistical optimisation showed that weakly acidic conditions (pH 5) and low agitation speed (100 rpm) were required for maximum laccase production from mandarin peelings (0.5 g/200 mL) and NaNO3 (0.25 g/200 mL) in Hb9c, maize stover (0.50 g/200 mL) and NaNO3 (0.050 g/200mL) in Berl11b2 while a lower agitation speed (50 rpm) was required for maximum laccase output from 2.0 g/200 mL maize stover and 0.050 g/200 mL KNO3 in Ie1c. However, 2.50 g/200 mL wheat bran, 0.050 g/200 mL yeast extract and 50 rpm agitiation under acidic conditions (pH3) yielded maximum laccase titres in Hb16c. Further characterisation of Hb9c and Ie1c laccase secretions portrayed their polyextremotolerant capacities. They were active at a broad range of tempertaure (0-90 degreesC); with optima at 70°C (Hb9c) and 60°C (Ie1c), pH (3-11); with optima at pH 6 (Ie1c) and pH 8 (Hb9c), respectively, and were equally thermo- and pH-stable. Their activities were either improved or left unabated by high concentrations of cations, detergents, and chloride. In addition, catalytic activities of Hb9c and Ie1c laccase secretions increased when they were preincubated with 2 – 20 percent of fluoride, a potent inhibitor. Consequently, a molecular perspective depicted the isolates to have multiple homologous laccase encoding genes. The enzymes were successfully immobilised on solid supports comprising gelatin and Na-alginate with a recovery of cca. 85 percent residual activity after 8 cycles of oprertional stability experiments. The immobilised laccases were remarkable in the decolourisation of synthetic dyes, albeit, free forms also elicited satisfactory performances. Ultimately, the application of free laccases in denim bleaching, individually or with a blend of a mediator, ABTS, showed that denim colours could be bleached without the need for chemical bleaching agents. The results obtained suggest the bacteria laccases produced from lignocellulosic wastes may serve as potent degraders of phenolic pollutants in water and, may also contribute to the bioeconomy and promote greener techniques for industrial applications.
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Pharmacological investigations of Kedrostis africana (L.) Cogn. and Vernonia mespilifolia Less. used in folk medicine in the Eastern Cape, South Africa
- Authors: Unuofin, Jeremiah Oshiomame
- Date: 2017
- Subjects: Medicinal plants -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/9231 , vital:34307
- Description: The prevalence of obesity and its co-morbidity is increasing in South Africa. High calorie diet, sedentary lifestyle and the cultural belief that being fat or obese signifies beauty, wellness and wealth are major causative factors. This study was undertaken to scientifically validate two major medicinal plants used traditionally in the Raymond Mhlaba Municipality for the mespilifolia Less. were used singly and in combination. According to ethnobotanical studies,these two plants are regarded as wild plants and are only used for medicinal purposes. There has been a dearth of scientific reports on the two plants and to the best of our knowledge, this study is the first to investigate the nutritional, antioxidant, antimicrobial, safety and anti-obesity potentials of the two plants and their combination. This study revealed that both plants are rich in nutrients. K. africana had greater ash (16.28 percent), crude fat (1.12 percent), Ca (2505 mg/100g), Mg (485 mg/100g) and Fe (89.95 mg/100g) while V. mespilifolia showed higher crude fibre (29.24 percent), crude protein (10.75 percent), P (400 mg/100g), Na (570 mg/100g), Cu (1.55 mg/100g) and Mn (4.70 mg/100g). K. africana and V. mespilifolia both contributed 223.37 Kcal/kg and 237.37 Kcal/kg of energy respectively. The polyphenolic evaluation of the acetone, aqueous and ethanol extracts of the plants revealed that the acetone extract of the combination of both plants had higher total phenol (144.59 mgGAE/g) and flavonoid (803.93 mgQE/g) contents, the ethanol extract of the combined plant also had the highest tannin contents (1.25 mgTAE/g), while the acetone extracts of K. Africana had the highest proanthocyanidin content (585 mgCE/g). The antioxidant assays revealed that the ethanol extract for V. mespilifolia had higher scavenging potentials of ABTS, DPPH and vinitric oxide radicals while the aqueous extract of the combination of both had higher scavenging potential for hydrogen peroxide radicals. Evaluation of antimicrobial potential of the extracts using the minimial inhibitory concentration (MIC) assay against 6 bacteria (Actinomyces odontolyticus, Lactobacillus sakei, Staphylococcus aureus, Enterobacter cloacae, Pseudomonas aeruginosa and Bacteriodes thetaiotomicron) and 4 fungi (Candida albicans, Microsporium gypsum, Penicillium chrysogenum and Trichophyton tonsurans) revealed that the plants possess antimicrobial activity. The MIC of the extracts against the tested bacterial strains ranged from 2.5 mg/mL to 5 mg/mL acetone and ethanol extracts of V. mespilifolia and the combined plants as well as the ethanol extracts of K. africana. However, no activity was observed for the acetone extract of K. africana and aqueous extracts of V. mespilifolia and the combination of both plants. Only three fungal strains (Candida albicans, Microsporium gypsum and Penicillium chrysogenum) were susceptible to the organic extracts with an MIC 0.3125 mg/mL to 5 mg/mL while the aqueous extracts showed no activity against all the fungal strains. None of the plant extracts showed any activity against Trichophyton tonsurans. The brine shrimp toxicity test revealed that all the three extracts of V. mespilifolia, aqueous and ethanol extracts of K. africana and aqueous and acetone extracts of the combination of both plants were toxic in relative to Meyer’s index and other indices of toxicity. The cytotoxic effect of the aqueous and ethanol extracts of V. mespilifolia, K. africana and their combination were also evaluated using HeLa cells. From this study, all the extracts tested had IC50 values were greater than 20 μg/mL which connotes that they are not toxic. According to the American National Cancer Institute, crude plant extracts are considered cytotoxic in an in vitro assay when concentrations 20 μg/mL and below produce 50% inhibition of tumor cells, after an exposure time of 48 hours. In vivo acute evaluation of single oral administration of 2000 and 5000/kg body weight did not produce mortality or significant behavioral changes during 14 days observation. In addition, the sub-acute administration of the aqueous extract at 200, 400 and 600 mg/kg/bwt/ day over a period of 28 days revealed no mortality or morbidity. The weekly body and organ weight of the rats were not significantly different from those of the controls and extract treated rats. The aqueous extracts at all doses did not show any significant (p > 0.05) effect on biomarkers of liver and renal damage. Haematological evaluation revealed that oral administration of aqueous extracts of K. africana, V. mespilifolia and the combination of both plants did not induce anaemia or leucocytosis in the animals. Furthermore, histopathological evaluation of the internal organs revealed no detectable inflammation at the the doses administered over a period of 28 days. These results demonstrated that the aqueous extracts of K. africana, V. mespilifolia and the combination of both plants was potentially safe for consumption orally even in chronic administration. Enzyme based in-vitro antiobesity evaluation of the aqueous and ethanolic extracts of K. africana, V. mespilifolia and their combination revealed that the ethanol extracts of both plants and their combination exhibited moderate inhibitory activities against α-amylase, α- glucosidase and pancreatic lipase. However, the standards used for the various inhibition assays exhibited much higher inhibitory actions when compared to any of the extracts. This suggests that the mechanism by which these two plants and their combination exert anti-obesity effects are probably not by inhibition of key enzymes of carbohydrate and fat metabolism.
- Full Text:
- Authors: Unuofin, Jeremiah Oshiomame
- Date: 2017
- Subjects: Medicinal plants -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/9231 , vital:34307
- Description: The prevalence of obesity and its co-morbidity is increasing in South Africa. High calorie diet, sedentary lifestyle and the cultural belief that being fat or obese signifies beauty, wellness and wealth are major causative factors. This study was undertaken to scientifically validate two major medicinal plants used traditionally in the Raymond Mhlaba Municipality for the mespilifolia Less. were used singly and in combination. According to ethnobotanical studies,these two plants are regarded as wild plants and are only used for medicinal purposes. There has been a dearth of scientific reports on the two plants and to the best of our knowledge, this study is the first to investigate the nutritional, antioxidant, antimicrobial, safety and anti-obesity potentials of the two plants and their combination. This study revealed that both plants are rich in nutrients. K. africana had greater ash (16.28 percent), crude fat (1.12 percent), Ca (2505 mg/100g), Mg (485 mg/100g) and Fe (89.95 mg/100g) while V. mespilifolia showed higher crude fibre (29.24 percent), crude protein (10.75 percent), P (400 mg/100g), Na (570 mg/100g), Cu (1.55 mg/100g) and Mn (4.70 mg/100g). K. africana and V. mespilifolia both contributed 223.37 Kcal/kg and 237.37 Kcal/kg of energy respectively. The polyphenolic evaluation of the acetone, aqueous and ethanol extracts of the plants revealed that the acetone extract of the combination of both plants had higher total phenol (144.59 mgGAE/g) and flavonoid (803.93 mgQE/g) contents, the ethanol extract of the combined plant also had the highest tannin contents (1.25 mgTAE/g), while the acetone extracts of K. Africana had the highest proanthocyanidin content (585 mgCE/g). The antioxidant assays revealed that the ethanol extract for V. mespilifolia had higher scavenging potentials of ABTS, DPPH and vinitric oxide radicals while the aqueous extract of the combination of both had higher scavenging potential for hydrogen peroxide radicals. Evaluation of antimicrobial potential of the extracts using the minimial inhibitory concentration (MIC) assay against 6 bacteria (Actinomyces odontolyticus, Lactobacillus sakei, Staphylococcus aureus, Enterobacter cloacae, Pseudomonas aeruginosa and Bacteriodes thetaiotomicron) and 4 fungi (Candida albicans, Microsporium gypsum, Penicillium chrysogenum and Trichophyton tonsurans) revealed that the plants possess antimicrobial activity. The MIC of the extracts against the tested bacterial strains ranged from 2.5 mg/mL to 5 mg/mL acetone and ethanol extracts of V. mespilifolia and the combined plants as well as the ethanol extracts of K. africana. However, no activity was observed for the acetone extract of K. africana and aqueous extracts of V. mespilifolia and the combination of both plants. Only three fungal strains (Candida albicans, Microsporium gypsum and Penicillium chrysogenum) were susceptible to the organic extracts with an MIC 0.3125 mg/mL to 5 mg/mL while the aqueous extracts showed no activity against all the fungal strains. None of the plant extracts showed any activity against Trichophyton tonsurans. The brine shrimp toxicity test revealed that all the three extracts of V. mespilifolia, aqueous and ethanol extracts of K. africana and aqueous and acetone extracts of the combination of both plants were toxic in relative to Meyer’s index and other indices of toxicity. The cytotoxic effect of the aqueous and ethanol extracts of V. mespilifolia, K. africana and their combination were also evaluated using HeLa cells. From this study, all the extracts tested had IC50 values were greater than 20 μg/mL which connotes that they are not toxic. According to the American National Cancer Institute, crude plant extracts are considered cytotoxic in an in vitro assay when concentrations 20 μg/mL and below produce 50% inhibition of tumor cells, after an exposure time of 48 hours. In vivo acute evaluation of single oral administration of 2000 and 5000/kg body weight did not produce mortality or significant behavioral changes during 14 days observation. In addition, the sub-acute administration of the aqueous extract at 200, 400 and 600 mg/kg/bwt/ day over a period of 28 days revealed no mortality or morbidity. The weekly body and organ weight of the rats were not significantly different from those of the controls and extract treated rats. The aqueous extracts at all doses did not show any significant (p > 0.05) effect on biomarkers of liver and renal damage. Haematological evaluation revealed that oral administration of aqueous extracts of K. africana, V. mespilifolia and the combination of both plants did not induce anaemia or leucocytosis in the animals. Furthermore, histopathological evaluation of the internal organs revealed no detectable inflammation at the the doses administered over a period of 28 days. These results demonstrated that the aqueous extracts of K. africana, V. mespilifolia and the combination of both plants was potentially safe for consumption orally even in chronic administration. Enzyme based in-vitro antiobesity evaluation of the aqueous and ethanolic extracts of K. africana, V. mespilifolia and their combination revealed that the ethanol extracts of both plants and their combination exhibited moderate inhibitory activities against α-amylase, α- glucosidase and pancreatic lipase. However, the standards used for the various inhibition assays exhibited much higher inhibitory actions when compared to any of the extracts. This suggests that the mechanism by which these two plants and their combination exert anti-obesity effects are probably not by inhibition of key enzymes of carbohydrate and fat metabolism.
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Influence of trans-border trading activities on senior secondary school students' academic performance in economics in Ogun State, Nigeria
- Authors: Titus, Adesegun Benedict
- Date: 2018
- Subjects: Smuggling -- Education (Secondary) Borderlands -- Nigeria
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/9659 , vital:34814
- Description: The study investigated the influence of transborder trading activities on senior secondary school students’ academic performance in economics in Ogun state, Nigeria. A descriptive survey research design involving 320 students that comprised males and females were selected through stratified random sampling technique. Two self-developed instruments were used: student questionnaire on transborder trading activities (SQTTA) with a Cronbach alpha index of 0.7845; and the economics achievement test (EAT) with a co-efficient index of r= 0.814. The results of the data collected were collated, coded, analyzed and interpreted through the use of descriptive research statistics of frequency, mean, percentages, and standard deviation while Step-wise regression analysis was used to test the hypotheses raised in the study, and the inferential statistics t-test was used to test the significant differences between the independent and dependent variables. The results revealed that there is a positive significant influence of smuggling on students’ academic performance in economics concepts (t=4.123; df =307, p<0.05) and a negative significant influence of school location on students’ academic performance in economics concepts (t=0.952; df=307, p>0.05). The study revealed that the most prevalent transborder trading activities like smuggling of used tyres, small firearms and fairly used clothes had negative influence on students’ academic performance. Based on these findings, discussions were focused on the involvement of students in trans-border trading activities and the location of schools, amongst others, which has no significant influence on students’ academic performance. However, it was recommended that schools should not be located near border areas in future.
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- Authors: Titus, Adesegun Benedict
- Date: 2018
- Subjects: Smuggling -- Education (Secondary) Borderlands -- Nigeria
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/9659 , vital:34814
- Description: The study investigated the influence of transborder trading activities on senior secondary school students’ academic performance in economics in Ogun state, Nigeria. A descriptive survey research design involving 320 students that comprised males and females were selected through stratified random sampling technique. Two self-developed instruments were used: student questionnaire on transborder trading activities (SQTTA) with a Cronbach alpha index of 0.7845; and the economics achievement test (EAT) with a co-efficient index of r= 0.814. The results of the data collected were collated, coded, analyzed and interpreted through the use of descriptive research statistics of frequency, mean, percentages, and standard deviation while Step-wise regression analysis was used to test the hypotheses raised in the study, and the inferential statistics t-test was used to test the significant differences between the independent and dependent variables. The results revealed that there is a positive significant influence of smuggling on students’ academic performance in economics concepts (t=4.123; df =307, p<0.05) and a negative significant influence of school location on students’ academic performance in economics concepts (t=0.952; df=307, p>0.05). The study revealed that the most prevalent transborder trading activities like smuggling of used tyres, small firearms and fairly used clothes had negative influence on students’ academic performance. Based on these findings, discussions were focused on the involvement of students in trans-border trading activities and the location of schools, amongst others, which has no significant influence on students’ academic performance. However, it was recommended that schools should not be located near border areas in future.
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Ontological Model for Xhosa Beadwork in Marginalised Rural Communities: A Case of the Eastern Cape
- Authors: Tinarwo, Loyd
- Date: 2019
- Subjects: Ontology Beadwork
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/15749 , vital:40516
- Description: In South Africa, computational ontologies have gained traction and are increasingly viewed as one of the viable solutions to address the problem of fragmented and unstructured nature of indigenous knowledge (IK) particularly in the marginalized rural communities. The continual existence of IK in tacit form has impeded the use of IK as a potential resource that can catalyze socio-economic and cultural development in South Africa. This study was, therefore, designed to address part of this challenge by developing a Xhosa Beadwork Ontology (XBO) with the goal of structuring the domain knowledge into a reusable body of knowledge. Such a reusable body of knowledge promotes efficient sharing of a common understanding of Xhosa Beadwork in a computational form. The XBO is in OWL 2 DL. The development of the XBO was informed by the NeOn methodology and the iterativeincremental ontology development life cycle within the ambit of Action Research (AR). The XBO was developed around personal ornamentation Xhosa Beadwork consisting of Necklace, Headband, Armlet, Waistband, Bracelet, and Anklet. In this study, the XBO was evaluated focused on ascertaining that the created ontology is a comprehensive representation of the Xhosa Beadwork and is of the required standard. In addition, the XBO was documented into a human understandable and readable resource and was published. The outcome of the study has indicated that the XBO is an adequate, shareable and reusable semantic artifact that can indeed support the formalization and preservation of IK in the domain of Xhosa Beadwork
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- Authors: Tinarwo, Loyd
- Date: 2019
- Subjects: Ontology Beadwork
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/15749 , vital:40516
- Description: In South Africa, computational ontologies have gained traction and are increasingly viewed as one of the viable solutions to address the problem of fragmented and unstructured nature of indigenous knowledge (IK) particularly in the marginalized rural communities. The continual existence of IK in tacit form has impeded the use of IK as a potential resource that can catalyze socio-economic and cultural development in South Africa. This study was, therefore, designed to address part of this challenge by developing a Xhosa Beadwork Ontology (XBO) with the goal of structuring the domain knowledge into a reusable body of knowledge. Such a reusable body of knowledge promotes efficient sharing of a common understanding of Xhosa Beadwork in a computational form. The XBO is in OWL 2 DL. The development of the XBO was informed by the NeOn methodology and the iterativeincremental ontology development life cycle within the ambit of Action Research (AR). The XBO was developed around personal ornamentation Xhosa Beadwork consisting of Necklace, Headband, Armlet, Waistband, Bracelet, and Anklet. In this study, the XBO was evaluated focused on ascertaining that the created ontology is a comprehensive representation of the Xhosa Beadwork and is of the required standard. In addition, the XBO was documented into a human understandable and readable resource and was published. The outcome of the study has indicated that the XBO is an adequate, shareable and reusable semantic artifact that can indeed support the formalization and preservation of IK in the domain of Xhosa Beadwork
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Agriculture vocational education programme and the promotion of job creation skills in the Free State Technical Vocational Education and Training College
- Authors: Thwala, William Mandla
- Date: 2017
- Subjects: Vocational education -- South Africa -- Free State Job creation -- South Africa -- Free State
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/11172 , vital:37199
- Description: The aim of the study was to investigate agriculture educational programme and the promotion of job creation skills in the OFS FET College. The interpretivism paradigm and design approach were adopted in this qualitative research. The sample consisted of three final year students, three facilitators and one coordinator. The non-probability and purposive sampling techniques was used for the qualitative research. The qualitative data was descriptive, and thematically analysed. The study found that there is a big demand for agricultural professional in South Africa but very few are choosing this career. The quality of education in agricultural sector is not where it should be. The demand for skilled people in the sector is growing, while the number of students enrolling in agriculture-related training continues to decrease. Africa’s agricultural education is failing to produce a new wave of farmers. The study found that FET colleges did not train and provide enough skills to students to enhance development in agriculture sectors and therefore make students non-productive at labour market. The study also found that the FET colleges had left a trail of low skills, partially educated and jobless youth behind. The study also found that the curriculum tended to be outmoded, irrelevant to adequately address the challenges facing modern agriculture .The curriculum still focused on farm production rather than encompassing all segments of agricultural value chains, entrepreneurship, and agriculture business processing market. Agriculture forms the basic food security of every country .It contributes a large proportion of gross domestic product in many developing countries and is the source of income and subsistence for many of the poorest and most vulnerable individuals and households.
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- Authors: Thwala, William Mandla
- Date: 2017
- Subjects: Vocational education -- South Africa -- Free State Job creation -- South Africa -- Free State
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/11172 , vital:37199
- Description: The aim of the study was to investigate agriculture educational programme and the promotion of job creation skills in the OFS FET College. The interpretivism paradigm and design approach were adopted in this qualitative research. The sample consisted of three final year students, three facilitators and one coordinator. The non-probability and purposive sampling techniques was used for the qualitative research. The qualitative data was descriptive, and thematically analysed. The study found that there is a big demand for agricultural professional in South Africa but very few are choosing this career. The quality of education in agricultural sector is not where it should be. The demand for skilled people in the sector is growing, while the number of students enrolling in agriculture-related training continues to decrease. Africa’s agricultural education is failing to produce a new wave of farmers. The study found that FET colleges did not train and provide enough skills to students to enhance development in agriculture sectors and therefore make students non-productive at labour market. The study also found that the FET colleges had left a trail of low skills, partially educated and jobless youth behind. The study also found that the curriculum tended to be outmoded, irrelevant to adequately address the challenges facing modern agriculture .The curriculum still focused on farm production rather than encompassing all segments of agricultural value chains, entrepreneurship, and agriculture business processing market. Agriculture forms the basic food security of every country .It contributes a large proportion of gross domestic product in many developing countries and is the source of income and subsistence for many of the poorest and most vulnerable individuals and households.
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Land rental policy and land market in Mashonaland East Province, Zimbabwe: implications on farmer decisions, efficiency and equity under A1 and A2 models
- Authors: Tatsvarei , Simbarashe
- Date: 2019
- Subjects: Farms, Small Agricultural extension work
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/15666 , vital:40501
- Description: Government promulgated the land rental policy starting in the year 2007. The policy required that A1 (market residual) and A2 (indigenous commercial) farmers pay rentals to the state. Since then, there has also been an emerging trend in which farmers have been renting in and out land, resulting in an informal market for land rentals. The study therefore assessed farmers’ perceptions of land rental policy and evaluated the possible association of this policy to farmers’ decision making on land rental markets as well as its implications on farmers’ efficiency and equity. The study was carried out in Mashonaland East Province of Zimbabwe, covering two districts, Goromonzi and Marondera. The focus was specifically on A1 and A2 farmers, as the rental policy was directed at these resettlement models only and much of the informal land rental markets were prevalent among these categories of farmers. Data collection utilised the survey approach. This was supported by key informant interviews and focus group discussions, with a final sample of 339 households selected using multi-stage sampling method. Survey data were transcribed on CsPro 6, and analysed using Stata, SPSS and Frontier 4.1. Results showed that about a third of household respondents was from Marondera and twothirds was from Goromonzi, while 79% and 21% was A1 and A2 farmers respectively. About 80% was male headed households and the remainder was female headed households. About half of the households were not participating in land rental markets while the other half was split almost equally between those renting-in and renting-out land. In general, A2 farmers were better in agricultural productivity than A1 farmers. It was concluded that farmers had a fairly good knowledge of the agricultural land rental policy enunciated in the Finance Bills. A1 farmers were more knowledgeable than A2 farmers, but no vii significant differences were observed between male and female headed households and farmers involved and not involved in land rental markets. Farmers’ attitudes in relation to policy were categorised as fair, with significant differences based on gender and land market participation. Practice scores showed a poor adherence to policy for all categories of farmers. Overall perceptions of farmers on rental policy was inferred as fair with significant differences existing between land rental market participants and non-participants (autarky). The results of a bivariate Tobit model results showed that the decision to rent-in land was significantly influenced by gender, household income, permanent labour, cultivated area, tenure certainty, irrigable land size and crop diversification. On the other hand, age, permanent labour, irrigable land size and crop diversification significantly influenced farmers’ decisions to rent-out land. The conclusion was that household characteristics, land endowments and transaction costs significantly influenced the decision to rent-in land while the former two were strong in influencing renting-out decisions. Results from the linearized Cobb Douglas model showed that economic efficiency for most farmers was above 50%. Farmers renting-out land under A1 were found to be the most economically efficient, followed by those who were renting-in and least efficient were farmers not participating in land rental markets, though the differences were marginal. For the A2 model, renting-in farmers were the most efficient, followed by those in autarky position, while renting-out farmers were the least. Overall, the most efficient farmers were those renting-in, followed by those renting-out while farmers in autarky were the least efficient. Overall efficiency was higher for A2 farmers than for A1 farmers. For farmers not participating in rental markets, the sources of inefficiency were crop type, crop area and labour. For farmers renting-in, it was proportion of irrigable land, size of irrigable land, crop type, crop area and viii labour, while inefficiency drivers for renting-out farmers were crop type and associated area. Equity analysis showed that participation in land rental markets reduced inequality for farmers in the two districts and male and female headed households. Inequality was increased among A1 farmers and remained unchanged among A2 farmers. Overall, the emerging position was that participation in land rental markets resulted in higher efficiency and reduced inequality in land holding among the sampled farmers. It is recommended that government should be consistent on land rental policy and bring into place effective administration of land rental policy. Government may also consider formal acceptance of land rental markets in light of the marginal efficiency and equity benefits shown in the study. However, formalizing land rental markets alone may not be a panacea to improved efficiency and needs to be supported by other productivity measures given the average efficiency values for farmers. Crop and livestock production based on compatibility with the natural regions and defined minimum size of land should be encouraged to improve efficiency
- Full Text:
- Authors: Tatsvarei , Simbarashe
- Date: 2019
- Subjects: Farms, Small Agricultural extension work
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/15666 , vital:40501
- Description: Government promulgated the land rental policy starting in the year 2007. The policy required that A1 (market residual) and A2 (indigenous commercial) farmers pay rentals to the state. Since then, there has also been an emerging trend in which farmers have been renting in and out land, resulting in an informal market for land rentals. The study therefore assessed farmers’ perceptions of land rental policy and evaluated the possible association of this policy to farmers’ decision making on land rental markets as well as its implications on farmers’ efficiency and equity. The study was carried out in Mashonaland East Province of Zimbabwe, covering two districts, Goromonzi and Marondera. The focus was specifically on A1 and A2 farmers, as the rental policy was directed at these resettlement models only and much of the informal land rental markets were prevalent among these categories of farmers. Data collection utilised the survey approach. This was supported by key informant interviews and focus group discussions, with a final sample of 339 households selected using multi-stage sampling method. Survey data were transcribed on CsPro 6, and analysed using Stata, SPSS and Frontier 4.1. Results showed that about a third of household respondents was from Marondera and twothirds was from Goromonzi, while 79% and 21% was A1 and A2 farmers respectively. About 80% was male headed households and the remainder was female headed households. About half of the households were not participating in land rental markets while the other half was split almost equally between those renting-in and renting-out land. In general, A2 farmers were better in agricultural productivity than A1 farmers. It was concluded that farmers had a fairly good knowledge of the agricultural land rental policy enunciated in the Finance Bills. A1 farmers were more knowledgeable than A2 farmers, but no vii significant differences were observed between male and female headed households and farmers involved and not involved in land rental markets. Farmers’ attitudes in relation to policy were categorised as fair, with significant differences based on gender and land market participation. Practice scores showed a poor adherence to policy for all categories of farmers. Overall perceptions of farmers on rental policy was inferred as fair with significant differences existing between land rental market participants and non-participants (autarky). The results of a bivariate Tobit model results showed that the decision to rent-in land was significantly influenced by gender, household income, permanent labour, cultivated area, tenure certainty, irrigable land size and crop diversification. On the other hand, age, permanent labour, irrigable land size and crop diversification significantly influenced farmers’ decisions to rent-out land. The conclusion was that household characteristics, land endowments and transaction costs significantly influenced the decision to rent-in land while the former two were strong in influencing renting-out decisions. Results from the linearized Cobb Douglas model showed that economic efficiency for most farmers was above 50%. Farmers renting-out land under A1 were found to be the most economically efficient, followed by those who were renting-in and least efficient were farmers not participating in land rental markets, though the differences were marginal. For the A2 model, renting-in farmers were the most efficient, followed by those in autarky position, while renting-out farmers were the least. Overall, the most efficient farmers were those renting-in, followed by those renting-out while farmers in autarky were the least efficient. Overall efficiency was higher for A2 farmers than for A1 farmers. For farmers not participating in rental markets, the sources of inefficiency were crop type, crop area and labour. For farmers renting-in, it was proportion of irrigable land, size of irrigable land, crop type, crop area and viii labour, while inefficiency drivers for renting-out farmers were crop type and associated area. Equity analysis showed that participation in land rental markets reduced inequality for farmers in the two districts and male and female headed households. Inequality was increased among A1 farmers and remained unchanged among A2 farmers. Overall, the emerging position was that participation in land rental markets resulted in higher efficiency and reduced inequality in land holding among the sampled farmers. It is recommended that government should be consistent on land rental policy and bring into place effective administration of land rental policy. Government may also consider formal acceptance of land rental markets in light of the marginal efficiency and equity benefits shown in the study. However, formalizing land rental markets alone may not be a panacea to improved efficiency and needs to be supported by other productivity measures given the average efficiency values for farmers. Crop and livestock production based on compatibility with the natural regions and defined minimum size of land should be encouraged to improve efficiency
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Assessment of student satisfaction on institutional factors influencing student retention in one comprehensive university in the Eastern Cape Province of South Africa
- Authors: Stofile, Regina N
- Date: 2017
- Subjects: Education, Higher -- South Africa College dropouts Dropouts -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/9450 , vital:34353
- Description: In all higher education institutions across the world, the student retention and success is an issue of concern and a pressing one. Students invest heavily in their higher education, while institutions in turn, lose a considerable sum of money for each student that drops out due to dissatisfaction with institutional services. The purpose of this quantitative methods research study, employing a survey design, was to assess student satisfaction with institutional factors that influence student satisfaction in higher education. The research questions focused on student satisfaction factors namely; academic advising, academic support, teaching approaches, assessment techniques, learning facilities, student funding services, student accommodation and administrative services. The study used structured questionnaire, with Likert scale type of question items, to collect data from the respondents These were hand delivered to 650 students in four campuses of the selected university. SPSS was used for data analysis. Major findings revealed that the selected institutional factors significantly impacted on student satisfaction, and their decisions to stay within the institution. Based on the results of the study, a framework to assist the institution ensure that student are receiving the services that they need from the institution as early as possible, was proposed. The study provided therefore the useful data for institutions to use in their quality enhancement activities. The result of the study can be incorporated into enrolment management planning and the intervention strategies, to improve the success of students at the selected institution in Eastern Cape.
- Full Text:
- Authors: Stofile, Regina N
- Date: 2017
- Subjects: Education, Higher -- South Africa College dropouts Dropouts -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/9450 , vital:34353
- Description: In all higher education institutions across the world, the student retention and success is an issue of concern and a pressing one. Students invest heavily in their higher education, while institutions in turn, lose a considerable sum of money for each student that drops out due to dissatisfaction with institutional services. The purpose of this quantitative methods research study, employing a survey design, was to assess student satisfaction with institutional factors that influence student satisfaction in higher education. The research questions focused on student satisfaction factors namely; academic advising, academic support, teaching approaches, assessment techniques, learning facilities, student funding services, student accommodation and administrative services. The study used structured questionnaire, with Likert scale type of question items, to collect data from the respondents These were hand delivered to 650 students in four campuses of the selected university. SPSS was used for data analysis. Major findings revealed that the selected institutional factors significantly impacted on student satisfaction, and their decisions to stay within the institution. Based on the results of the study, a framework to assist the institution ensure that student are receiving the services that they need from the institution as early as possible, was proposed. The study provided therefore the useful data for institutions to use in their quality enhancement activities. The result of the study can be incorporated into enrolment management planning and the intervention strategies, to improve the success of students at the selected institution in Eastern Cape.
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Effects of pre-slaughter stress, sex and breed on blood stress indicators, heat shock proteins, glycolytic potential and lamb quality
- Authors: Stempa, Thuthuzelwa
- Date: 2019
- Subjects: Animal welfare , Meat--Quality
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/15376 , vital:40402
- Description: The main objective of this study was to determine the effects of pre-slaughter stress (transportation distance and lairage duration), sex and breed on blood stress indicators, heat shock proteins, post-mortem muscle metabolites (glycogen, glucose, glucose-6-phosphate and lactate), glycolytic potential and meat quality attributes from lambs slaughtered at a commercial abattoir. The study was conducted in a high-throughput commercial abattoir in the Buffalo City local municipality of the Eastern Cape Province, South Africa. A total of a hundred eight-month old Dorper and Merino lambs, both male and female, were used in the study. Blood samples for the analysis of glucose and lactate levels were collected using 10.0 mL disposable Becton Dickinson vacutainer tubes treated with fluoride oxalate (grey top) whereas those for determination of cortisol and heat shock protein 70 (HSPA1A) levels were collected using plasma separating vacutainer tubes (SSTTMII, gold top), and those for analysis of creatine kinase and lactate dehydrogenase were collected using 10.0 ml vacutainer tubes treated with Ethylenediaminetetraacetic acid (EDTA). Meat samples (~50 g) for the measurement of post-mortem energy metabolites (glycogen, lactate glucose-6-phosphate and glucose content) were collected from the Muscularis longimissius thoracis et lumborum (LTL) of each carcass ~30 minutes after slaughter and immediately frozen in liquid nitrogen (-196 oC) to prevent further glycolysis. Cold carcass weight (CCW), warm carcass weight (WCW) and carcass fatness (CF) was measured. Meat pH and temperature were measured at iii 45 minutes (initial pH), 6 hours and 24 hours ultimate pH (pHu) post-mortem. Meat colour coordinates [lightness (L*), redness (a*), yellowness (b*), hue angle (H*), chroma (C*)] were also measured 24 hours after slaughter. Furthermore, thawing loss (TL%), cooking loss (CL%) and warner braztler shear force (WBSF) was measured in the LTL 7 days post slaughter. Breed had a significant effect on plasma HSPA1A, plasma lactate, WCW, CCW, L*, muscle glycogen and WBSF. Sex had a significant effect on plasma HSPA1A and pHu. Pearson‘s correlations showed that meat muscle glycogen was positively correlated to glycolytic potential (P<0.001; r=0.63) and initial pH (P<0.05, r=0.20). Muscle lactate was positively correlated to muscle glucose (P<0.01, r=0.30) and glycolytic potential (P<0.001, r=0.79). A positive correlation was shown between muscle glucose and glycolytic potential (P<0.05, r=0.23). The level of LDH was affected by the distance travelled by lambs prior to slaughter. Lairage duration did not affect the levels of CK and LDH. Principal Component Analysis showed a relationship between distance travelled and CK and LDH; and that CK and LDH also influenced the quality of meat from lambs. With respect to sex and breed, the results indicate that female and Dorper were more stressed than male and Merino respectively. Muscle glycolytic potential and post-mortem metabolites have an impact on the quality of meat produced and the Merino had higher muscle glycogen levels at slaughter; hence they produced better meat quality compared to the Dorper. Moreover, no associations were seen between pHu and blood stress indicators. These results indicate that blood stress indicators at exsanguination cannot be used as useful indicators of dark cutting condition in lamb. A relationship between pHu, muscle glycogen and glycolytic potential was established and thus meat pHu can be used as a reliable indicator of tenderness in lamb.
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- Authors: Stempa, Thuthuzelwa
- Date: 2019
- Subjects: Animal welfare , Meat--Quality
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/15376 , vital:40402
- Description: The main objective of this study was to determine the effects of pre-slaughter stress (transportation distance and lairage duration), sex and breed on blood stress indicators, heat shock proteins, post-mortem muscle metabolites (glycogen, glucose, glucose-6-phosphate and lactate), glycolytic potential and meat quality attributes from lambs slaughtered at a commercial abattoir. The study was conducted in a high-throughput commercial abattoir in the Buffalo City local municipality of the Eastern Cape Province, South Africa. A total of a hundred eight-month old Dorper and Merino lambs, both male and female, were used in the study. Blood samples for the analysis of glucose and lactate levels were collected using 10.0 mL disposable Becton Dickinson vacutainer tubes treated with fluoride oxalate (grey top) whereas those for determination of cortisol and heat shock protein 70 (HSPA1A) levels were collected using plasma separating vacutainer tubes (SSTTMII, gold top), and those for analysis of creatine kinase and lactate dehydrogenase were collected using 10.0 ml vacutainer tubes treated with Ethylenediaminetetraacetic acid (EDTA). Meat samples (~50 g) for the measurement of post-mortem energy metabolites (glycogen, lactate glucose-6-phosphate and glucose content) were collected from the Muscularis longimissius thoracis et lumborum (LTL) of each carcass ~30 minutes after slaughter and immediately frozen in liquid nitrogen (-196 oC) to prevent further glycolysis. Cold carcass weight (CCW), warm carcass weight (WCW) and carcass fatness (CF) was measured. Meat pH and temperature were measured at iii 45 minutes (initial pH), 6 hours and 24 hours ultimate pH (pHu) post-mortem. Meat colour coordinates [lightness (L*), redness (a*), yellowness (b*), hue angle (H*), chroma (C*)] were also measured 24 hours after slaughter. Furthermore, thawing loss (TL%), cooking loss (CL%) and warner braztler shear force (WBSF) was measured in the LTL 7 days post slaughter. Breed had a significant effect on plasma HSPA1A, plasma lactate, WCW, CCW, L*, muscle glycogen and WBSF. Sex had a significant effect on plasma HSPA1A and pHu. Pearson‘s correlations showed that meat muscle glycogen was positively correlated to glycolytic potential (P<0.001; r=0.63) and initial pH (P<0.05, r=0.20). Muscle lactate was positively correlated to muscle glucose (P<0.01, r=0.30) and glycolytic potential (P<0.001, r=0.79). A positive correlation was shown between muscle glucose and glycolytic potential (P<0.05, r=0.23). The level of LDH was affected by the distance travelled by lambs prior to slaughter. Lairage duration did not affect the levels of CK and LDH. Principal Component Analysis showed a relationship between distance travelled and CK and LDH; and that CK and LDH also influenced the quality of meat from lambs. With respect to sex and breed, the results indicate that female and Dorper were more stressed than male and Merino respectively. Muscle glycolytic potential and post-mortem metabolites have an impact on the quality of meat produced and the Merino had higher muscle glycogen levels at slaughter; hence they produced better meat quality compared to the Dorper. Moreover, no associations were seen between pHu and blood stress indicators. These results indicate that blood stress indicators at exsanguination cannot be used as useful indicators of dark cutting condition in lamb. A relationship between pHu, muscle glycogen and glycolytic potential was established and thus meat pHu can be used as a reliable indicator of tenderness in lamb.
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Diversity, host plant range and ecology of Lepidoptera stem borers in South Africa
- Authors: Stemele, Mxolisi Arnold
- Date: 2019
- Subjects: Lepidoptera Host plants Stem borers
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/15409 , vital:40405
- Description: The biology and ecology of Lepidopteran pests stem borers has been extensively studied because of the economic importance of pest species such as Busseola fusca (Fuller) (Noctuidae), Sesamia calamistis (Hampson) (Noctuidae), Chilo partellus (Swinhoe) (Crambidae), and Eldana saccharina (Walker) (Pyralidae). Knowledge relating to diversity, infestation dynamics, and host plant range is readily available. In natural vegetation, the variety of stem borers is higher than that found in agroecosystems. However, there is a paucity of South African studies that explain the observed differences in diversity between the two systems. Stem borers are also known to exhibit species-specific ecological requirements, which influence their distribution between African countries. South African biomes are classified based on vegetation structure and climate, which happens to be the most critical factors that affect the distribution of phytophagous insects. This makes biomes an excellent model to investigate diversity and distribution of stem borer species. In this study, we investigated diversity, distribution and species composition in four biomes. The results showed that diversity and distribution of the stem borers in natural vegetation was determined by host plant distribution. Stem borer diversity correlated with high diversity of host plants. Thirty-two stem borer species were collected from 27 host plants and another three from light traps. Widely distributed host plants supported a higher diversity of stem borers, which is consistent with the resource availability hypotheses. Non-metric dimensional scale unfolding revealed disparity in host plant preference and plant species composition between the various stem borer families (Kruskal’s Stress = 0.16). Tortricidae species and Sesamia typhae (Le rü) (Noctuidae) feed exclusively on hydrophytic Cyperaceae species. The majority of Noctuidae, Crambidae and Phycitidae species collected were oligophagous on terrestrial Poaceae, with a few polyphagous exceptions feeding on hydrophytic Cyperaceae and Typhaceae. Additionally, species composition of Poaceae host plants differed between 8 Crambidae and the Phycitidae species. Stem borer species composition between biomes revealed the presence of distinct host plants (2D stress = 0.09) and stem borer (2D stress = 0.13) communities. The stem borer abundance and diversity were strongly correlated (R2 = 0.64), but species diversity (R2 = - 0.95) and host plant diversity (R2 = - 0.85) were inversely correlated to altitude. Based on these results it was concluded that stem borer diversity and distribution in natural vegetation was influenced by host plant diversity and distribution as well as climate associated with altitudinal gradients. In the last two decades, four stem borer species previously known on wild host plants; Busseola segeta (Bowden), Busseola phaia (Bowden), Pirateolea piscator (Fletcher) and Conicofrontia sesamoides (Hampson) have invaded cultivated crops. These invasions remained undetected because of a shortage of surveys, habitat transformation and misidentifications. Misidentifications are common among stem borers due to the considerable resemblance between morphospecies. In this study, we assessed the capacity of the mitochondrial gene Cytochrome c oxidase (COI) to delineate closely related species to develop monitoring and early detection of invasive species and to assess migration patterns and gene flow between the populations. The results demonstrated that COI is an effective DNA marker for species delineation and assessment of intra- and interspecific genetic relationship. The K2P distances and phylogenetic tree defined boundaries between Noctuidae species with high resolution. No divergence distance was detected between intraspecific species, but for the congener species, divergence distance was 0.044%-0.111% with an average of 0.076%. The average interspecies K2P distance (0.57%) was 5-15 times higher than the congener species distances. Phylogenetic analysis revealed the presence of two clades. Busseola and Sesamia species were connected in a monophyletic clade with a strong (93%) bootstrap. The second monophyletic clade comprised of a cluster of Pirateolea, Acrapex and Conicofrontia species, and this was also supported with 9 a strong bootstrap (100%). The gene flow study revealed low levels of genetic differentiation between the populations of B. fusca collected from different maize producing areas in South Africa. This low genetic differentiation was consistent with high gene flow. The number of effective migrants between the populations was between 8 and 99 individuals per generation. These results indicate high connectivity between the populations.
- Full Text:
- Authors: Stemele, Mxolisi Arnold
- Date: 2019
- Subjects: Lepidoptera Host plants Stem borers
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/15409 , vital:40405
- Description: The biology and ecology of Lepidopteran pests stem borers has been extensively studied because of the economic importance of pest species such as Busseola fusca (Fuller) (Noctuidae), Sesamia calamistis (Hampson) (Noctuidae), Chilo partellus (Swinhoe) (Crambidae), and Eldana saccharina (Walker) (Pyralidae). Knowledge relating to diversity, infestation dynamics, and host plant range is readily available. In natural vegetation, the variety of stem borers is higher than that found in agroecosystems. However, there is a paucity of South African studies that explain the observed differences in diversity between the two systems. Stem borers are also known to exhibit species-specific ecological requirements, which influence their distribution between African countries. South African biomes are classified based on vegetation structure and climate, which happens to be the most critical factors that affect the distribution of phytophagous insects. This makes biomes an excellent model to investigate diversity and distribution of stem borer species. In this study, we investigated diversity, distribution and species composition in four biomes. The results showed that diversity and distribution of the stem borers in natural vegetation was determined by host plant distribution. Stem borer diversity correlated with high diversity of host plants. Thirty-two stem borer species were collected from 27 host plants and another three from light traps. Widely distributed host plants supported a higher diversity of stem borers, which is consistent with the resource availability hypotheses. Non-metric dimensional scale unfolding revealed disparity in host plant preference and plant species composition between the various stem borer families (Kruskal’s Stress = 0.16). Tortricidae species and Sesamia typhae (Le rü) (Noctuidae) feed exclusively on hydrophytic Cyperaceae species. The majority of Noctuidae, Crambidae and Phycitidae species collected were oligophagous on terrestrial Poaceae, with a few polyphagous exceptions feeding on hydrophytic Cyperaceae and Typhaceae. Additionally, species composition of Poaceae host plants differed between 8 Crambidae and the Phycitidae species. Stem borer species composition between biomes revealed the presence of distinct host plants (2D stress = 0.09) and stem borer (2D stress = 0.13) communities. The stem borer abundance and diversity were strongly correlated (R2 = 0.64), but species diversity (R2 = - 0.95) and host plant diversity (R2 = - 0.85) were inversely correlated to altitude. Based on these results it was concluded that stem borer diversity and distribution in natural vegetation was influenced by host plant diversity and distribution as well as climate associated with altitudinal gradients. In the last two decades, four stem borer species previously known on wild host plants; Busseola segeta (Bowden), Busseola phaia (Bowden), Pirateolea piscator (Fletcher) and Conicofrontia sesamoides (Hampson) have invaded cultivated crops. These invasions remained undetected because of a shortage of surveys, habitat transformation and misidentifications. Misidentifications are common among stem borers due to the considerable resemblance between morphospecies. In this study, we assessed the capacity of the mitochondrial gene Cytochrome c oxidase (COI) to delineate closely related species to develop monitoring and early detection of invasive species and to assess migration patterns and gene flow between the populations. The results demonstrated that COI is an effective DNA marker for species delineation and assessment of intra- and interspecific genetic relationship. The K2P distances and phylogenetic tree defined boundaries between Noctuidae species with high resolution. No divergence distance was detected between intraspecific species, but for the congener species, divergence distance was 0.044%-0.111% with an average of 0.076%. The average interspecies K2P distance (0.57%) was 5-15 times higher than the congener species distances. Phylogenetic analysis revealed the presence of two clades. Busseola and Sesamia species were connected in a monophyletic clade with a strong (93%) bootstrap. The second monophyletic clade comprised of a cluster of Pirateolea, Acrapex and Conicofrontia species, and this was also supported with 9 a strong bootstrap (100%). The gene flow study revealed low levels of genetic differentiation between the populations of B. fusca collected from different maize producing areas in South Africa. This low genetic differentiation was consistent with high gene flow. The number of effective migrants between the populations was between 8 and 99 individuals per generation. These results indicate high connectivity between the populations.
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Re-interpreting the history of 'the rural' visual in the Eastern Cape, 1948-1976
- Authors: Steele, Candice Alexandra
- Date: 2018
- Subjects: Medical photography -- South Africa -- Exhibitions Photography in ethnology -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/11064 , vital:37027
- Description: The thesis engages with the photographic collection of Dr Pauline Ingle, an amateur photographer who lived and worked in the former Transkei as a medical doctor from 1948-1976. As a visual history project situated within critical visual studies, the thesis is concerned to attend to the disciplinary optics that have conditioned seeing and constituted genres; but also the ways in which these genres have constituted subjects and corralled them into positions commensurate with the spatialised demarcations of the rural and the urban, and the attendant associations of tradition and modernity. The thesis begins by exploring the biography of Pauline Ingle and tracks the movement of the photographs from a private collection into the public realm and its constitution as an archive. The thesis then moves into a discussion of the key determinants of the ethnographic genre and its entwinement with the discipline of anthropology, as a foundation against which to investigate the limits of reading her images within this genre and the disruptions that are discernible through an aesthetics of proximity and forms of image-making that do not control the visual field. Through a theorisation that proposes the image as an act, various readings are brought to bear on the images through the lens of the social and political. Mobilising the concepts of social acts and acts of citizenship, allows for a reading that breaks with the disciplinary conditioning that has fixed subject positions into ‘the native subject’ and the ‘liberal subject’ and calls into question the construction of the human. By proposing the subject as migrant, is to signal that the question of the human/subject is more complex and convoluted than previously thought.
- Full Text:
- Authors: Steele, Candice Alexandra
- Date: 2018
- Subjects: Medical photography -- South Africa -- Exhibitions Photography in ethnology -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/11064 , vital:37027
- Description: The thesis engages with the photographic collection of Dr Pauline Ingle, an amateur photographer who lived and worked in the former Transkei as a medical doctor from 1948-1976. As a visual history project situated within critical visual studies, the thesis is concerned to attend to the disciplinary optics that have conditioned seeing and constituted genres; but also the ways in which these genres have constituted subjects and corralled them into positions commensurate with the spatialised demarcations of the rural and the urban, and the attendant associations of tradition and modernity. The thesis begins by exploring the biography of Pauline Ingle and tracks the movement of the photographs from a private collection into the public realm and its constitution as an archive. The thesis then moves into a discussion of the key determinants of the ethnographic genre and its entwinement with the discipline of anthropology, as a foundation against which to investigate the limits of reading her images within this genre and the disruptions that are discernible through an aesthetics of proximity and forms of image-making that do not control the visual field. Through a theorisation that proposes the image as an act, various readings are brought to bear on the images through the lens of the social and political. Mobilising the concepts of social acts and acts of citizenship, allows for a reading that breaks with the disciplinary conditioning that has fixed subject positions into ‘the native subject’ and the ‘liberal subject’ and calls into question the construction of the human. By proposing the subject as migrant, is to signal that the question of the human/subject is more complex and convoluted than previously thought.
- Full Text:
Muscle nanostructure, fat colour related fatty acids and Check-All-That-Apply visual profiling of South African A2 beef longissimus
- Authors: Soji, Zimkhitha
- Date: 2019
- Subjects: Meat -- Quality
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/15264 , vital:40332
- Description: The main objective of this study was to determine the effect of muscle nanostructure on tenderness, fat colour related fatty acids and Check-All-That-Apply visual profiling of South African A2 beef longissimus. Fifty two A-class steers (n=52) of five breeds (Bonsmara (n=19), Beef master (n=7), Hereford (n=9) and Simbra (n=17)) typically processed in different South African feedlots were studied. The animals were humanely slaughtered at an abattoir following the commercial standard procedures. Fat colour measurements (CIE b*) were taken at the P8 site on hot carcasses at the abattoir. Carcass mass (warm and cold) was recorded at the slaughter line before chilling (warm) and after chilling (cold) while pH0 and temperature were measured at 45 minutes post-mortem on the Longissimus thoracis et lumborum (LTL) muscle. Thereafter, a 20 g subsection of the LTL muscle on the left side of each carcass was sampled for muscle nanostructure analysis. At 24 hours post-slaughter, ultimate pH (pH24) was measured, further subsections of the LTL muscle (20 g) were harvested for further muscle nanostructure analysis and 2.5 kg of the LTL muscle was also harvested for analysis of tenderness, fatty acids and sensory evaluation. The muscle nanostructure (myofibril diameter (MYD), myofibril spacing (MYS), muscle fibre diameter (MFD), muscle fibre spacing (MFS) and sarcomere length (SL)) was analysed using the scanning electron microscope (SEM) while tenderness was measured using Warner Bratzler Shear Force after 45mins, 24hrs, 3 and 7 days aging period at -20 ºC refrigerator temperature. Some proximate fractions (total extractable intramuscular fat (Fat %), Fat Free Dry matter (FFDM %) and Moisture content) and fatty acid profile were measured using extracted fat and fatty acid indices (desaturase index, atherogenicity index) were calculated. Lastly a Check-All-That-Apply visual profiling method rated by an 80-member consumer panel was done to assess consumer meat preferences and perceptions of Bonsmara, Hereford and Simbra A2 fresh steaks. At 45mins post-slaughter breed affected (P<0.05) MYD and MYS, while at 24hrs breed affected MFD and MFS only. Early post-mortem pH (pH0) had no effect on the muscle nanostructure and tenderness while ultimate pH (pH24) affected MYD and MYS only. Muscle temperature at 45mins affected (P<0.05) the MYD, MFD and MFS, while 24hrs muscle temperature affected (P<0.05) MYD only. Tenderness was not related to the muscle nanostructure early post-mortem and there was no uniformity on the changes in muscle nanostructure and tenderness from early post-mortem to 24hrs against the multifaceted carcass mass, muscle pH and temperature effects. During ageing, breed affected the MYD and MYS at 45mins, while at 24hrs in addition to the myofibril structure breed also had an effect on muscle fibre bundle characteristics (MFD and MFS). The changes in MYD, MYS and MFS became constant on day 3 while variations in the MFD still progressed. There was no uniformity on the SL pattern during ageing and a very weak linear relationship between tenderness, SL, MFD and MFS was observed. Notably there was also no uniformity on how the muscle texture features; including the surface structure, fibre separation, and the mechanism of muscle contraction and relaxation; changed throughout the ageing period across and within the breeds. Moreover, breed had a significant effect on pentadecyclic acid, total saturated fatty acids (SFA) and docosahexanoic acid. Differences (P<0.05) in SFA, monounsaturated fatty acids (MUFA), polyunsaturated fatty acids (PUFA), n-6, n-3, fatty acid ratios, and desaturase index were observed among the white, creamy-white and creamy fat colour. The distribution of fatty acid classes was SFA>MUFA>PUFA in descending order of concentrations of mean values (44.19:40.06:15.75, respectively), while the n-6: n-3 ratio was 12:1. In sensory evaluation, consumers indicated how they would prefer to pay premium for meat with guaranteed muscle and fat colour, low fat content, high marbling and tenderness. Consumers observed breed differences (P<0.05) in muscle fibre separation and muscle colour. The overall liking of each attribute was more on moderate bright cherry red lean colour, moderate yellow fat, very abundant marbling and slight separation of muscle fibres. Differences on discrete liking of each attribute among consumers had an effect on the overall liking of each steak with Hereford steaks being more preferred by consumers. It was concluded that meat from beef animals within the same feeding regime has a different fatty acid composition owing to different breed synthetic pathways and feed ingredients and that meat tenderness is not affected by the muscle nanostructure early post-mortem. However, during ageing, meat tenderness is directly linked to breed related myofibril structure changes in particular the myofibril diameter, spacing between myofibrils and their interaction; while the muscle texture features, fibre diameter, spacing between muscle fibres and sarcomere length explain the non-uniformity of beef tenderness. Also the organoleptic and health related quality of meat assumed more importance among consumers in sensory evaluation. Thus meat classification systems should include more credence aspects or indicators that support credence quality of meat
- Full Text:
- Authors: Soji, Zimkhitha
- Date: 2019
- Subjects: Meat -- Quality
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/15264 , vital:40332
- Description: The main objective of this study was to determine the effect of muscle nanostructure on tenderness, fat colour related fatty acids and Check-All-That-Apply visual profiling of South African A2 beef longissimus. Fifty two A-class steers (n=52) of five breeds (Bonsmara (n=19), Beef master (n=7), Hereford (n=9) and Simbra (n=17)) typically processed in different South African feedlots were studied. The animals were humanely slaughtered at an abattoir following the commercial standard procedures. Fat colour measurements (CIE b*) were taken at the P8 site on hot carcasses at the abattoir. Carcass mass (warm and cold) was recorded at the slaughter line before chilling (warm) and after chilling (cold) while pH0 and temperature were measured at 45 minutes post-mortem on the Longissimus thoracis et lumborum (LTL) muscle. Thereafter, a 20 g subsection of the LTL muscle on the left side of each carcass was sampled for muscle nanostructure analysis. At 24 hours post-slaughter, ultimate pH (pH24) was measured, further subsections of the LTL muscle (20 g) were harvested for further muscle nanostructure analysis and 2.5 kg of the LTL muscle was also harvested for analysis of tenderness, fatty acids and sensory evaluation. The muscle nanostructure (myofibril diameter (MYD), myofibril spacing (MYS), muscle fibre diameter (MFD), muscle fibre spacing (MFS) and sarcomere length (SL)) was analysed using the scanning electron microscope (SEM) while tenderness was measured using Warner Bratzler Shear Force after 45mins, 24hrs, 3 and 7 days aging period at -20 ºC refrigerator temperature. Some proximate fractions (total extractable intramuscular fat (Fat %), Fat Free Dry matter (FFDM %) and Moisture content) and fatty acid profile were measured using extracted fat and fatty acid indices (desaturase index, atherogenicity index) were calculated. Lastly a Check-All-That-Apply visual profiling method rated by an 80-member consumer panel was done to assess consumer meat preferences and perceptions of Bonsmara, Hereford and Simbra A2 fresh steaks. At 45mins post-slaughter breed affected (P<0.05) MYD and MYS, while at 24hrs breed affected MFD and MFS only. Early post-mortem pH (pH0) had no effect on the muscle nanostructure and tenderness while ultimate pH (pH24) affected MYD and MYS only. Muscle temperature at 45mins affected (P<0.05) the MYD, MFD and MFS, while 24hrs muscle temperature affected (P<0.05) MYD only. Tenderness was not related to the muscle nanostructure early post-mortem and there was no uniformity on the changes in muscle nanostructure and tenderness from early post-mortem to 24hrs against the multifaceted carcass mass, muscle pH and temperature effects. During ageing, breed affected the MYD and MYS at 45mins, while at 24hrs in addition to the myofibril structure breed also had an effect on muscle fibre bundle characteristics (MFD and MFS). The changes in MYD, MYS and MFS became constant on day 3 while variations in the MFD still progressed. There was no uniformity on the SL pattern during ageing and a very weak linear relationship between tenderness, SL, MFD and MFS was observed. Notably there was also no uniformity on how the muscle texture features; including the surface structure, fibre separation, and the mechanism of muscle contraction and relaxation; changed throughout the ageing period across and within the breeds. Moreover, breed had a significant effect on pentadecyclic acid, total saturated fatty acids (SFA) and docosahexanoic acid. Differences (P<0.05) in SFA, monounsaturated fatty acids (MUFA), polyunsaturated fatty acids (PUFA), n-6, n-3, fatty acid ratios, and desaturase index were observed among the white, creamy-white and creamy fat colour. The distribution of fatty acid classes was SFA>MUFA>PUFA in descending order of concentrations of mean values (44.19:40.06:15.75, respectively), while the n-6: n-3 ratio was 12:1. In sensory evaluation, consumers indicated how they would prefer to pay premium for meat with guaranteed muscle and fat colour, low fat content, high marbling and tenderness. Consumers observed breed differences (P<0.05) in muscle fibre separation and muscle colour. The overall liking of each attribute was more on moderate bright cherry red lean colour, moderate yellow fat, very abundant marbling and slight separation of muscle fibres. Differences on discrete liking of each attribute among consumers had an effect on the overall liking of each steak with Hereford steaks being more preferred by consumers. It was concluded that meat from beef animals within the same feeding regime has a different fatty acid composition owing to different breed synthetic pathways and feed ingredients and that meat tenderness is not affected by the muscle nanostructure early post-mortem. However, during ageing, meat tenderness is directly linked to breed related myofibril structure changes in particular the myofibril diameter, spacing between myofibrils and their interaction; while the muscle texture features, fibre diameter, spacing between muscle fibres and sarcomere length explain the non-uniformity of beef tenderness. Also the organoleptic and health related quality of meat assumed more importance among consumers in sensory evaluation. Thus meat classification systems should include more credence aspects or indicators that support credence quality of meat
- Full Text:
Genetic characteristics of Human Immunodeficiency Virus-1, and deter-minants of late presentation for care and Diabetes mellitus amongst newly diagnosed Human Immunodeficiency Virus positive patients in the Eastern Cape, South Africa.
- Authors: Sogbanmu, Olufunso Oladipo
- Date: 2019
- Subjects: HIV infections
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/${Handle} , vital:40495
- Description: Phylogenies may help to characterize transmission pairs, enhance contact tracing and outbreak investigations, track the origin and spread of epidemics over place and time, and to identify patterns of onward Human Immunodeficiency-Virus (HIV) transmission among risk groups. If the pattern and evolution of HIV drug resistance can be mapped, this may influence the development of guidelines in the clinical management of HIV especially with issues relating to prevalence of primary drug resistance and its impact on outcomes of present antiretroviral treatment (ART) regimen in use and the ability to trace and track the development of drug resistant strains. The roll-out of the test and treat Programme for newly diagnosed HIV infected pa-tient, seeks to identify HIV infected individuals early and to prevent morbidity and mortality associated with the late presentation for HIV care. The determination of the magnitude of ‘late presentation’ and or ‘presentation with advanced HIV disease’ can be used in very diverse settings and for many purposes. It provides a unified way to define the problem, thereby targeting appropriate interventions to prevent the detrimental outcomes associated with late presentation to care. The subtle relationship between HIV and diabetes mellitus (DM) may also help in formulating better preventive programs to aid the control of non-communicable diseases such as DM. This cross-sectional study includes a purposive selection of 335 HIV positive patients attending the voluntary counselling and Testing (VCT) and HIV Counselling and Testing (HCT) centres and outpatient departments at Cecilia Makiwane Hospital and the HCT sites at the Buffalo District municipality community health centres, Eastern Cape Province, South Africa. Late or delayed presentation of HIV infection was defined as CD4 cell count beneath 350 cells/μL and/or patients presenting with an AIDS-defining event at the first follow-up regardless of the CD4 cell count. Chapter 1 provides the general introduction had an overview of the introduction to the study, the statement of the research problem, hypothesis, the aim and the objectives. xx Chapter 2 looked in-depth at the HIV, case definition, the latest epidemiology of HIV, the HIV genome, the life cycle of HIV, its diagnosis, the classes of antiretroviral drugs, development of drug resistance. Chapter 3 highlighted the prevalence of Transmitted Drug Resistance (TDR) with focus on the protease gene. RNA was extracted from blood samples of 72 newly diagnosed HIV-1 patients attending some HIV testing and counselling clinics from August 2016 to July 2017. Protease fragments were amplified with specific primers by RT-PCR followed by nested PCR. The amplified products were sequenced using the ABI 360 sequencer, edited with Geneious version 9.1.5 and translated into amino acid with BioEdit software. Drug related resistance mutation (DRMs) analysis was performed on all the protease sequences in accordance with the 2009 WHO list of surveillance drug resistance mutations by submitting the edited sequences to Stanford HIV drug interpretation programme and the international AIDS society-USA guidelines for query of drug resistance associated mutations while phylogenetic analysis was performed using MEGA 6 to allocate all viral sequences into subtypes. In the study, a total of 52/72 (71.1%) reliable HIV-1 protease sequences were obtained in which subtyping and drug resistance mutations were performed. Two (3.8%) major Protease resistance associated mutation (V82A/L and L90M) were observed while another polymorphism like L10F, T74S, Q58E, L10I/V and M46V were also identified. Phylogenetic analyses delineated all the sequences as HIV-1 subtype C. Chapter 4 describes the prevalence and the determinants of late presentation amongst newly diagnosed HIV positive individuals in the Eastern Cape. It indicates the extent of the prevalence of patients presenting to care and at what HIV stage they were assessing health care services since the inception of the ‘test and treat’ strategy. It is a cross-sectional study where a total of 335 newly diagnosed patients were recruited consecutively be-tween August 2016 and July 2017. Late presenter for HIV care was defined in accordance with the European Late Presenter Consensus working group as a patient who reports for care when the CD4 count is below 350 cells/μL and/or when there is an established Aids- xxi defining clinical condition, irrespective of CD4 count. Adjusted and unadjusted logistic regression analysis was used to examine the determinants of late HIV diagnosis. The study showed that 60% of patients were late presenters, with 35% presenting with advanced disease. The major determinants identified were being male and low level of education. This led to recommendations directed at ensuring programmes that targets men in identifying their HIV status and assess care at early stage to prevents the morbidity and mortality associated with delayed presentation. Also, it was recommended that effort should be made to improve access to education and also include HIV related topics into the educational curriculum. Chapter 5 aimed to describe the prevalence and determinants of DM amongst newly diagnosed HIV positive individuals. This is a cross-sectional study which recruited 335 patients between August 2016 and September 2017. Definition for diabetes mellitus was made based on the SEDMSA 2015 guideline of HBA1C of above 6.5%. Adjusted and unadjusted logistic regression analysis was used to examine the determinants of abnormal glycated haemoglobin. Findings showed the prevalence of DM at about 6% amongst newly diagnosed HIV positive individuals. This is similar to findings in other study within the country, but a bit lower than what was obtained in the developed countries. The role of older age (above 40 years) as predisposing factor to development of diabetes in newly diagnosed HIV positive individual was well noted and taken. This ensures that screening for DM should be targeted at elderly HIV positive individuals. The grey area of the appropriate mode of diagnostic test to use to diagnose HIV is still debatable, however, a combination of HBA1c and fasting blood sugar (FBS) may improve the diagnosis of DM in this population group. In chapter 6, the general conclusions, recommendations and future perspectives of the study are reflected.
- Full Text:
- Authors: Sogbanmu, Olufunso Oladipo
- Date: 2019
- Subjects: HIV infections
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/${Handle} , vital:40495
- Description: Phylogenies may help to characterize transmission pairs, enhance contact tracing and outbreak investigations, track the origin and spread of epidemics over place and time, and to identify patterns of onward Human Immunodeficiency-Virus (HIV) transmission among risk groups. If the pattern and evolution of HIV drug resistance can be mapped, this may influence the development of guidelines in the clinical management of HIV especially with issues relating to prevalence of primary drug resistance and its impact on outcomes of present antiretroviral treatment (ART) regimen in use and the ability to trace and track the development of drug resistant strains. The roll-out of the test and treat Programme for newly diagnosed HIV infected pa-tient, seeks to identify HIV infected individuals early and to prevent morbidity and mortality associated with the late presentation for HIV care. The determination of the magnitude of ‘late presentation’ and or ‘presentation with advanced HIV disease’ can be used in very diverse settings and for many purposes. It provides a unified way to define the problem, thereby targeting appropriate interventions to prevent the detrimental outcomes associated with late presentation to care. The subtle relationship between HIV and diabetes mellitus (DM) may also help in formulating better preventive programs to aid the control of non-communicable diseases such as DM. This cross-sectional study includes a purposive selection of 335 HIV positive patients attending the voluntary counselling and Testing (VCT) and HIV Counselling and Testing (HCT) centres and outpatient departments at Cecilia Makiwane Hospital and the HCT sites at the Buffalo District municipality community health centres, Eastern Cape Province, South Africa. Late or delayed presentation of HIV infection was defined as CD4 cell count beneath 350 cells/μL and/or patients presenting with an AIDS-defining event at the first follow-up regardless of the CD4 cell count. Chapter 1 provides the general introduction had an overview of the introduction to the study, the statement of the research problem, hypothesis, the aim and the objectives. xx Chapter 2 looked in-depth at the HIV, case definition, the latest epidemiology of HIV, the HIV genome, the life cycle of HIV, its diagnosis, the classes of antiretroviral drugs, development of drug resistance. Chapter 3 highlighted the prevalence of Transmitted Drug Resistance (TDR) with focus on the protease gene. RNA was extracted from blood samples of 72 newly diagnosed HIV-1 patients attending some HIV testing and counselling clinics from August 2016 to July 2017. Protease fragments were amplified with specific primers by RT-PCR followed by nested PCR. The amplified products were sequenced using the ABI 360 sequencer, edited with Geneious version 9.1.5 and translated into amino acid with BioEdit software. Drug related resistance mutation (DRMs) analysis was performed on all the protease sequences in accordance with the 2009 WHO list of surveillance drug resistance mutations by submitting the edited sequences to Stanford HIV drug interpretation programme and the international AIDS society-USA guidelines for query of drug resistance associated mutations while phylogenetic analysis was performed using MEGA 6 to allocate all viral sequences into subtypes. In the study, a total of 52/72 (71.1%) reliable HIV-1 protease sequences were obtained in which subtyping and drug resistance mutations were performed. Two (3.8%) major Protease resistance associated mutation (V82A/L and L90M) were observed while another polymorphism like L10F, T74S, Q58E, L10I/V and M46V were also identified. Phylogenetic analyses delineated all the sequences as HIV-1 subtype C. Chapter 4 describes the prevalence and the determinants of late presentation amongst newly diagnosed HIV positive individuals in the Eastern Cape. It indicates the extent of the prevalence of patients presenting to care and at what HIV stage they were assessing health care services since the inception of the ‘test and treat’ strategy. It is a cross-sectional study where a total of 335 newly diagnosed patients were recruited consecutively be-tween August 2016 and July 2017. Late presenter for HIV care was defined in accordance with the European Late Presenter Consensus working group as a patient who reports for care when the CD4 count is below 350 cells/μL and/or when there is an established Aids- xxi defining clinical condition, irrespective of CD4 count. Adjusted and unadjusted logistic regression analysis was used to examine the determinants of late HIV diagnosis. The study showed that 60% of patients were late presenters, with 35% presenting with advanced disease. The major determinants identified were being male and low level of education. This led to recommendations directed at ensuring programmes that targets men in identifying their HIV status and assess care at early stage to prevents the morbidity and mortality associated with delayed presentation. Also, it was recommended that effort should be made to improve access to education and also include HIV related topics into the educational curriculum. Chapter 5 aimed to describe the prevalence and determinants of DM amongst newly diagnosed HIV positive individuals. This is a cross-sectional study which recruited 335 patients between August 2016 and September 2017. Definition for diabetes mellitus was made based on the SEDMSA 2015 guideline of HBA1C of above 6.5%. Adjusted and unadjusted logistic regression analysis was used to examine the determinants of abnormal glycated haemoglobin. Findings showed the prevalence of DM at about 6% amongst newly diagnosed HIV positive individuals. This is similar to findings in other study within the country, but a bit lower than what was obtained in the developed countries. The role of older age (above 40 years) as predisposing factor to development of diabetes in newly diagnosed HIV positive individual was well noted and taken. This ensures that screening for DM should be targeted at elderly HIV positive individuals. The grey area of the appropriate mode of diagnostic test to use to diagnose HIV is still debatable, however, a combination of HBA1c and fasting blood sugar (FBS) may improve the diagnosis of DM in this population group. In chapter 6, the general conclusions, recommendations and future perspectives of the study are reflected.
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Challenges faced by grandparents in caring for their grandchildren in Mdlankomo location, Libode, Eastern Cape
- Authors: Soganga, Aseza
- Date: 2019
- Subjects: Grandparents as parents Grandchildren -- Care
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/16188 , vital:40692
- Description: The study aimed to investigate the challenges that older grandparents face in caring for their grandchildren in Mdlankomo Location, Libode, Eastern Cape. The study intended to achieve three (3) objectives: (i) to establish factors that make caregiving of children by their grandparents challenging, (ii) to establish resources that grandparents need to care for their grandchildren and (iii) to establish the availability of resources required by the grandparents to care for their grandchildren and its possible gaps. The study utilized qualitative research approach, and date collection methods used were in-depth interviews, focus group discussion and key informant method. The number of participants was 34 in total consisting of 23 grandparents and 11 key informants. The findings of the study showed that death of children’s own parents; cultural expectations, youth unemployment, abdication of parental responsibilities, youth unemployment, and carelessness of biological parents were the major reasons for grandparents to care for their grandchildren. The study findings also revealed that grandparents in this caregiving experience both benefits and barriers. The findings further revealed that there are gaps in welfare services, medical services and education. Therefore, the researcher recommended that, those in power should be interested, eager and inquisitive enough about certain aspects that need attention in caregiving of children by their grandparents.
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- Authors: Soganga, Aseza
- Date: 2019
- Subjects: Grandparents as parents Grandchildren -- Care
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/16188 , vital:40692
- Description: The study aimed to investigate the challenges that older grandparents face in caring for their grandchildren in Mdlankomo Location, Libode, Eastern Cape. The study intended to achieve three (3) objectives: (i) to establish factors that make caregiving of children by their grandparents challenging, (ii) to establish resources that grandparents need to care for their grandchildren and (iii) to establish the availability of resources required by the grandparents to care for their grandchildren and its possible gaps. The study utilized qualitative research approach, and date collection methods used were in-depth interviews, focus group discussion and key informant method. The number of participants was 34 in total consisting of 23 grandparents and 11 key informants. The findings of the study showed that death of children’s own parents; cultural expectations, youth unemployment, abdication of parental responsibilities, youth unemployment, and carelessness of biological parents were the major reasons for grandparents to care for their grandchildren. The study findings also revealed that grandparents in this caregiving experience both benefits and barriers. The findings further revealed that there are gaps in welfare services, medical services and education. Therefore, the researcher recommended that, those in power should be interested, eager and inquisitive enough about certain aspects that need attention in caregiving of children by their grandparents.
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Evaluation of the implementation of local economic development policy for poverty alleviation at selected municipalities in the province of eastern cape (2012-2014)
- Authors: Sidumo, Andile Morrison
- Date: 2016
- Subjects: Economic development -- South Africa -- Eastern Cape Sustainable development -- South Africa -- Eastern Cape Poverty -- Government policy -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/7708 , vital:30708
- Description: This thesis evaluated the implementation of local economic development policy for poverty alleviation at selected municipalities in the Province of the Eastern Cape. Poverty is a global challenge of sustainable development that faces communities at international, national, provincial and local sphere of government however, the focus was at selected municipalities in the Province of Eastern Cape. It is the responsibility of municipal authorities to satisfy the basic needs and promote the general welfare of communities at specific geographic areas in the Province which is vastly rural depending on agriculture and partly on the industrial development. Local economic development is a tool or method to alleviate poverty.
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- Authors: Sidumo, Andile Morrison
- Date: 2016
- Subjects: Economic development -- South Africa -- Eastern Cape Sustainable development -- South Africa -- Eastern Cape Poverty -- Government policy -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/7708 , vital:30708
- Description: This thesis evaluated the implementation of local economic development policy for poverty alleviation at selected municipalities in the Province of the Eastern Cape. Poverty is a global challenge of sustainable development that faces communities at international, national, provincial and local sphere of government however, the focus was at selected municipalities in the Province of Eastern Cape. It is the responsibility of municipal authorities to satisfy the basic needs and promote the general welfare of communities at specific geographic areas in the Province which is vastly rural depending on agriculture and partly on the industrial development. Local economic development is a tool or method to alleviate poverty.
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Trade liberalisation, the real exchange rate and sectoral employment : a case study of South Africa
- Authors: Sibanda, Kin
- Date: 2016
- Subjects: Foreign exchange rates Employment (Economic theory) Free trade -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/12777 , vital:39360
- Description: This study examined the relationship between trade liberalisation, the real exchange rate and sectoral employment in South Africa for the period 1994 to 2014. Firstly, using quarterly time series data, the Autoregressive Distributed Lag (ARDL) technique was employed to formally check if South African real exchange rates are responsive to trade liberalisation. This was done to see if trade liberalisation impacts real exchange rates in South Africa, to the extent that they cannot be controlled concurrently in the subsequent models. Based on the ARDL results, trade liberalisation does not have a significant effect on the exchange rate. However, when the real exchange rate is an independent variable of trade liberalisation, the results show that real exchange rates affect trade, specifically the export propensity index. The next step was to assess the impact of trade liberalisation and real exchange rate on sectoral employment using quarterly panel data for South Africa from 1994 to 2014 controlling for both sector-specific and macro-economic variables. The study employed diverse panel data analysis techniques to separate the sectoral effects, starting with broad sectors followed by the disaggregated sectors, to identify the sectors most affected by real exchange rates and trade liberalisation. The Generalised method of Moments (GMM) results reveal that a unit increase in exchange rate (implying appreciation), causes employment to go down by about 9 percent in South Africa. The same relationship is depicted from the Pooled Mean Group (PMG) estimations in both the short run and long run. Random coefficients (betas) show that the real exchange rate negatively affects the primary and secondary sector with a positive but insignificant effect on the tertiary sector. The sub-sectors negatively hit hard by real exchange rates are communication, mining and transport. The results also show that trade liberalisation is linked to both job destruction and job creation. The static models reveal that trade openness has a statistically positive and significant impact on employment in the short run while the PMG estimator results show that the effect is negative and only significant in the short run. The dynamic models (GMM and PMG) showed trade liberalisation (as proxied by trade openness and import propensity) has a statistical and significantly positive short run impact on employment. This implies that selective trade liberalisation strategies are needed in order for South Africa to maximise the gains from trade.
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- Authors: Sibanda, Kin
- Date: 2016
- Subjects: Foreign exchange rates Employment (Economic theory) Free trade -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/12777 , vital:39360
- Description: This study examined the relationship between trade liberalisation, the real exchange rate and sectoral employment in South Africa for the period 1994 to 2014. Firstly, using quarterly time series data, the Autoregressive Distributed Lag (ARDL) technique was employed to formally check if South African real exchange rates are responsive to trade liberalisation. This was done to see if trade liberalisation impacts real exchange rates in South Africa, to the extent that they cannot be controlled concurrently in the subsequent models. Based on the ARDL results, trade liberalisation does not have a significant effect on the exchange rate. However, when the real exchange rate is an independent variable of trade liberalisation, the results show that real exchange rates affect trade, specifically the export propensity index. The next step was to assess the impact of trade liberalisation and real exchange rate on sectoral employment using quarterly panel data for South Africa from 1994 to 2014 controlling for both sector-specific and macro-economic variables. The study employed diverse panel data analysis techniques to separate the sectoral effects, starting with broad sectors followed by the disaggregated sectors, to identify the sectors most affected by real exchange rates and trade liberalisation. The Generalised method of Moments (GMM) results reveal that a unit increase in exchange rate (implying appreciation), causes employment to go down by about 9 percent in South Africa. The same relationship is depicted from the Pooled Mean Group (PMG) estimations in both the short run and long run. Random coefficients (betas) show that the real exchange rate negatively affects the primary and secondary sector with a positive but insignificant effect on the tertiary sector. The sub-sectors negatively hit hard by real exchange rates are communication, mining and transport. The results also show that trade liberalisation is linked to both job destruction and job creation. The static models reveal that trade openness has a statistically positive and significant impact on employment in the short run while the PMG estimator results show that the effect is negative and only significant in the short run. The dynamic models (GMM and PMG) showed trade liberalisation (as proxied by trade openness and import propensity) has a statistical and significantly positive short run impact on employment. This implies that selective trade liberalisation strategies are needed in order for South Africa to maximise the gains from trade.
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An optimum wind power output model for concentrator augmented wind turbines (CAWTs)
- Authors: Shonhiwa, Chipo
- Date: 2017
- Subjects: Wind power Wind turbines
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/8692 , vital:33427
- Description: The aim of this study was to develop an optimum wind power output model for concentrator augmented wind turbines (CAWTs), which can operate in low wind speed areas. This study was done using computational fluid dynamics modelling (CFD), theoretical and experimental work. Currently the wind resource is contributing 2.5percent of the global electricity supply and is anticipated to increase to by 2050. Despite this, the contribution to wind energy consumption share by South Africa is still low having just exceeded in 2015. Like many other countries, South Africa agrees that climate change is one of the biggest challenges currently being faced by mankind and acknowledges that tackling it requires collaborative effort from all. The Integrated Resource Plan (IRP 2010-2030) passed in 2010 targets 26.3percent renewable energy contribution to national energy consumption by the year 2030 with 10.3percent coming from wind energy hence contributing to abatement of climate change. 1518percent 1 000 MW Small wind turbines are known for their vital contribution to providing electricity in remote areas. Their power output is mainly influenced by the turbine rotor diameter and wind speed which depend on tower height. A cost benefit analysis conducted basing on increasing wind speed by increasing the turbine tower height revealed that for small wind turbines, the optimal height is . Concentrator Augmented Wind Turbines (CAWTs) are one of several concepts that have been suggested to increase the power output per unit rotor cross-sectional area by increasing the wind speed upstream of the turbine. Although some research effort has been put in this area, the major drawback is that the effect of concentrator geometry and environmental conditions on the aerodynamics and hence ultimate performance of CAWTs is still not clear. Also, the CAWTs systems that have been made so far, do not track the wind resulting in CAWT systems receiving wind from one direction thus limiting their performance. 25 m Wind has a very low energy density in nature implying that a bigger rotor area is required to harness kinetic energy for generation of meaningful electrical energy. This has resulted in higher costs of producing energy from wind than conventional sources of energy such as fossil fuels and hydro. To lower the cost of wind energy, researchers have come up with several initiatives to boost wind turbine power output. A brief review of various concepts that have been used in this study included: history of wind turbines, South Africa’s political will to abatement of climate change, wind resource assessment, power output augmentation, estimation of air density, historical development of CAWTs, fundamental parameters influencing the performance of CAWTs, mathematical modelling of wind turbines and dynamic similarity. Some facts were borrowed from these concepts to come up with the current study and explain the observations. With a view to assess any concept, it is necessary to study the fundamental basis from which it originates. Thus, it was vital to develop a fundamental basis of CAWT performance from which solutions to currently prevailing questions on the relationships among the governing parameters were obtained. The momentum theory of bare wind turbines, which is also found in literature was described. A similar approach was then used for developing the theory of CAWT systems. The theories of concentrator losses, density variation with weather conditions and turbulence modelling were also described. It was of utmost significance to evaluate the wind power potential of the Western part of the Eastern Cape Province to assess whether there would be a need for the concentrator augmented wind turbines (CAWTs) in the province and all other regions with similar or lower wind speeds in the country. In this study, five-year-long, hourly average wind speed series between January 2009 and December 2013 for six weather stations in the western part of the Eastern Cape (Bisho, Fort Beaufort, Graaff–Reinet, Grahamstown, Port Elizabeth and Queenstown) were statistically analysed using the Weibull distribution function. The dimensionless Weibull shape parameter varied from 1.7 to 2.2. All the values were low indicating that there is widely dispersed data. This means that the data tend to be distributed uniformly over a relatively wide range wind speed. Therefore, this has a positive implication on wind power generation in all the studied areas because if a suitable turbine is installed, it would get enough wind speed to run for the greater part of the year. The scale parameter varied between 3.5 and 6.3. The values for all the sites except Port Elizabeth were relatively low implying that the days of high wind speeds are few. Therefore, wind turbines that require high wind speeds for operation are not suitable here.
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- Authors: Shonhiwa, Chipo
- Date: 2017
- Subjects: Wind power Wind turbines
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/8692 , vital:33427
- Description: The aim of this study was to develop an optimum wind power output model for concentrator augmented wind turbines (CAWTs), which can operate in low wind speed areas. This study was done using computational fluid dynamics modelling (CFD), theoretical and experimental work. Currently the wind resource is contributing 2.5percent of the global electricity supply and is anticipated to increase to by 2050. Despite this, the contribution to wind energy consumption share by South Africa is still low having just exceeded in 2015. Like many other countries, South Africa agrees that climate change is one of the biggest challenges currently being faced by mankind and acknowledges that tackling it requires collaborative effort from all. The Integrated Resource Plan (IRP 2010-2030) passed in 2010 targets 26.3percent renewable energy contribution to national energy consumption by the year 2030 with 10.3percent coming from wind energy hence contributing to abatement of climate change. 1518percent 1 000 MW Small wind turbines are known for their vital contribution to providing electricity in remote areas. Their power output is mainly influenced by the turbine rotor diameter and wind speed which depend on tower height. A cost benefit analysis conducted basing on increasing wind speed by increasing the turbine tower height revealed that for small wind turbines, the optimal height is . Concentrator Augmented Wind Turbines (CAWTs) are one of several concepts that have been suggested to increase the power output per unit rotor cross-sectional area by increasing the wind speed upstream of the turbine. Although some research effort has been put in this area, the major drawback is that the effect of concentrator geometry and environmental conditions on the aerodynamics and hence ultimate performance of CAWTs is still not clear. Also, the CAWTs systems that have been made so far, do not track the wind resulting in CAWT systems receiving wind from one direction thus limiting their performance. 25 m Wind has a very low energy density in nature implying that a bigger rotor area is required to harness kinetic energy for generation of meaningful electrical energy. This has resulted in higher costs of producing energy from wind than conventional sources of energy such as fossil fuels and hydro. To lower the cost of wind energy, researchers have come up with several initiatives to boost wind turbine power output. A brief review of various concepts that have been used in this study included: history of wind turbines, South Africa’s political will to abatement of climate change, wind resource assessment, power output augmentation, estimation of air density, historical development of CAWTs, fundamental parameters influencing the performance of CAWTs, mathematical modelling of wind turbines and dynamic similarity. Some facts were borrowed from these concepts to come up with the current study and explain the observations. With a view to assess any concept, it is necessary to study the fundamental basis from which it originates. Thus, it was vital to develop a fundamental basis of CAWT performance from which solutions to currently prevailing questions on the relationships among the governing parameters were obtained. The momentum theory of bare wind turbines, which is also found in literature was described. A similar approach was then used for developing the theory of CAWT systems. The theories of concentrator losses, density variation with weather conditions and turbulence modelling were also described. It was of utmost significance to evaluate the wind power potential of the Western part of the Eastern Cape Province to assess whether there would be a need for the concentrator augmented wind turbines (CAWTs) in the province and all other regions with similar or lower wind speeds in the country. In this study, five-year-long, hourly average wind speed series between January 2009 and December 2013 for six weather stations in the western part of the Eastern Cape (Bisho, Fort Beaufort, Graaff–Reinet, Grahamstown, Port Elizabeth and Queenstown) were statistically analysed using the Weibull distribution function. The dimensionless Weibull shape parameter varied from 1.7 to 2.2. All the values were low indicating that there is widely dispersed data. This means that the data tend to be distributed uniformly over a relatively wide range wind speed. Therefore, this has a positive implication on wind power generation in all the studied areas because if a suitable turbine is installed, it would get enough wind speed to run for the greater part of the year. The scale parameter varied between 3.5 and 6.3. The values for all the sites except Port Elizabeth were relatively low implying that the days of high wind speeds are few. Therefore, wind turbines that require high wind speeds for operation are not suitable here.
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