: the representation of rape in Lewis Nkosi’s Mating Birds and Arthur Maimane’s Hate No More
- Authors: Yawa, Sibulele Yola
- Date: 2021-02
- Subjects: South Africa--Politics and government--1994 , Post-apartheid era--South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/21134 , vital:47131
- Description: The main aim of this thesis is to provide a literary study through a comparative analysis of how sexual politics are played out in the texts Mating Birds by Lewis Nkosi and Hate No More by Arthur Maimane. It seeks to determine the modalities of representation of rape in each text and also to investigate the extent to which the novels are similar or different in the way in which they represent sexual politics or the politics of rape during the apartheid era. This investigation was done using Frantz Fanon‟s postcolonial theory and, particularly, his seminal work, Black Skin, White Masks. Most importantly, for the purpose of this study, is Fanon‟s chapter on the love/sexual relationships between the man of colour and the white woman. This is helpful as Fanon touches on what he believes the attraction of the man of colour to the white woman stems from. Using Fanon‟s theory, one discovers that the motivation for Ndi Sibiya to allegedly rape Veronica stems from his anger at the system of apartheid and its oppression of black people. This is similar to Philip Mokone‟s case; the novel explicitly states that he was motivated by anger and his rape of Jean Ryan was a form of communication to the white people and the apartheid system. , Thesis (MA) (English) -- University of Fort Hare, 2021
- Full Text:
- Date Issued: 2021-02
- Authors: Yawa, Sibulele Yola
- Date: 2021-02
- Subjects: South Africa--Politics and government--1994 , Post-apartheid era--South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/21134 , vital:47131
- Description: The main aim of this thesis is to provide a literary study through a comparative analysis of how sexual politics are played out in the texts Mating Birds by Lewis Nkosi and Hate No More by Arthur Maimane. It seeks to determine the modalities of representation of rape in each text and also to investigate the extent to which the novels are similar or different in the way in which they represent sexual politics or the politics of rape during the apartheid era. This investigation was done using Frantz Fanon‟s postcolonial theory and, particularly, his seminal work, Black Skin, White Masks. Most importantly, for the purpose of this study, is Fanon‟s chapter on the love/sexual relationships between the man of colour and the white woman. This is helpful as Fanon touches on what he believes the attraction of the man of colour to the white woman stems from. Using Fanon‟s theory, one discovers that the motivation for Ndi Sibiya to allegedly rape Veronica stems from his anger at the system of apartheid and its oppression of black people. This is similar to Philip Mokone‟s case; the novel explicitly states that he was motivated by anger and his rape of Jean Ryan was a form of communication to the white people and the apartheid system. , Thesis (MA) (English) -- University of Fort Hare, 2021
- Full Text:
- Date Issued: 2021-02
A biological assessment of the Cape knifejaw (Oplegnathus conwayi) an endemic South African teleost
- Authors: Foster, Ryan Matthew
- Date: 2021-10-29
- Subjects: Perciformes South Africa , Osteichthyes South Africa , Fisheries South Africa , Perciformes Growth , Perciformes Age , Perciformes Reproduction , Sampling Citizen participation , Cape knifejaw (Oplegnathus conwayi)
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/191057 , vital:45054
- Description: The South African spearfishery forms a small component of South Africa’s complex coastal fishery. Although the smallest, this fishery sector has the largest proportion of data deficient species, and as a consequence is poorly managed. Oplegnathus conwayi (Cape knifejaw) is an example of one of these species for which there is very little and outdated biological and ecological data. This species is among the top target species by recreational spearfishers in South Africa. This thesis aimed to improve our socio-ecological knowledge of the South African spearfishery through the collection of biological and Fishers’ Ecological Knowledge (FEK) information on Oplegnathus conwayi, and human dimension information on the South African spearfishery. Monthly biological samples were collected through routine sampling (spearfishing) and augmented by recreational spearfishers. A total of 254 fish were collected from the warm-temperate coastal zone (East London – Cape Agulhas), 28 from the sub-tropical zone (Durban – East London) and 23 from the cool-temperate zone (Cape Agulhas – Cape Point). The results indicated that Oplegnathus conwayi is a slow-growing species, with a maximum recorded age of 27 years. The population sex ratio was skewed, with males dominant in the population (1M:0.6F). The length- and age-frequency distributions were, however, similar for both sexes. No significant differences were observed between male and female growth (LRT, p > 0.05), with the overall population growth curve being best described as L(t) = 697.15(1-e-0.06(t-6.30)). Males matured at a slightly larger size than females, however, no significant differences were observed (LRT, p > 0.05). The length- and age- at-50% maturity was 330 mm (FL) and 5.73 years for the full population, respectively. Histological analyses showed that Oplegnathus conwayi are asynchronous spawners with a gonochoristic reproductive style. Macroscopic staging and gonadosomatic index results indicated a protracted spawning season for Oplegnathus conwayi, with a peak in spring. A survey was designed and disseminated to collect FEK on the biology and population status of Oplegnathus conwayi and human dimension information on South Africa’s spearfishery. A total of 103 survey responses were received, of which 94 were regarded as specialised (spearfishers who had greater experience, skill and avidity, and maintained spearfishing as an important component of their lifestyle) spearfishers. Based on the responses of the specialist spearfishers, the top four main species caught by spearfishers from this survey were Seriola lalandi (13.9%), Pachymetopon grande (11.7%), Oplegnathus conwayi (11.4%) and Sparodon durbanensis (11%), and the majority of respondents indicated that there had been no changes in abundance, size and catches of these species in the years that they had been spearfishing. Respondents indicated that Oplegnathus conwayi are most commonly targeted in the Eastern Cape and are found at depths of up to 40 m. Respondents also indicated that there may be a seasonal onshore (Summer/Winter) and offshore (Summer/Winter) migration with year-round spawning and a peak in November, December and January. The incorporation of spearfishers into the data collection, both through the collection of specimens and their FEK, was beneficial to this study. Besides providing samples from a broader geographical range than the primary collection area, the collaboration with spearfishers has promoted the inclusion of this group into the management system. The findings of this study also suggest that FEK data can be more reliable if the concept of recreational specialisation is incorporated into data collection. While the FEK suggested that the population was stable, a stock assessment is necessary to fully understand the population status and implement management strategies. Nevertheless, the key life history characteristics (slow growth and late maturation) observed in this study are characteristic of species that is vulnerable to overexploitation, and thus the precautionary approach should be applied. The reproductive information collected in this study has provided information for the implementation of an appropriate size limit regulation for Oplegnathus conwayi. Here, a minimum size limit of 400 mm TL, which corresponds approximately with the length-at-50% maturity of 330 mm FL, would be appropriate to allow fish to mature and spawn, and reduce the likelihood of recruitment overfishing. Reduction in the bag limit from five to two fish per person per day may also be appropriate as a precautionary measure until a stock assessment has been completed. Finally, the incorporation of stakeholder into biological collection and the use of FEK may be a useful approach for other data deficient species and in countries with limited resources for ecological research. , Thesis (MSc) -- Faculty of Science, Ichthyology and Fisheries Science, 2021
- Full Text:
- Date Issued: 2021-10-29
- Authors: Foster, Ryan Matthew
- Date: 2021-10-29
- Subjects: Perciformes South Africa , Osteichthyes South Africa , Fisheries South Africa , Perciformes Growth , Perciformes Age , Perciformes Reproduction , Sampling Citizen participation , Cape knifejaw (Oplegnathus conwayi)
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/191057 , vital:45054
- Description: The South African spearfishery forms a small component of South Africa’s complex coastal fishery. Although the smallest, this fishery sector has the largest proportion of data deficient species, and as a consequence is poorly managed. Oplegnathus conwayi (Cape knifejaw) is an example of one of these species for which there is very little and outdated biological and ecological data. This species is among the top target species by recreational spearfishers in South Africa. This thesis aimed to improve our socio-ecological knowledge of the South African spearfishery through the collection of biological and Fishers’ Ecological Knowledge (FEK) information on Oplegnathus conwayi, and human dimension information on the South African spearfishery. Monthly biological samples were collected through routine sampling (spearfishing) and augmented by recreational spearfishers. A total of 254 fish were collected from the warm-temperate coastal zone (East London – Cape Agulhas), 28 from the sub-tropical zone (Durban – East London) and 23 from the cool-temperate zone (Cape Agulhas – Cape Point). The results indicated that Oplegnathus conwayi is a slow-growing species, with a maximum recorded age of 27 years. The population sex ratio was skewed, with males dominant in the population (1M:0.6F). The length- and age-frequency distributions were, however, similar for both sexes. No significant differences were observed between male and female growth (LRT, p > 0.05), with the overall population growth curve being best described as L(t) = 697.15(1-e-0.06(t-6.30)). Males matured at a slightly larger size than females, however, no significant differences were observed (LRT, p > 0.05). The length- and age- at-50% maturity was 330 mm (FL) and 5.73 years for the full population, respectively. Histological analyses showed that Oplegnathus conwayi are asynchronous spawners with a gonochoristic reproductive style. Macroscopic staging and gonadosomatic index results indicated a protracted spawning season for Oplegnathus conwayi, with a peak in spring. A survey was designed and disseminated to collect FEK on the biology and population status of Oplegnathus conwayi and human dimension information on South Africa’s spearfishery. A total of 103 survey responses were received, of which 94 were regarded as specialised (spearfishers who had greater experience, skill and avidity, and maintained spearfishing as an important component of their lifestyle) spearfishers. Based on the responses of the specialist spearfishers, the top four main species caught by spearfishers from this survey were Seriola lalandi (13.9%), Pachymetopon grande (11.7%), Oplegnathus conwayi (11.4%) and Sparodon durbanensis (11%), and the majority of respondents indicated that there had been no changes in abundance, size and catches of these species in the years that they had been spearfishing. Respondents indicated that Oplegnathus conwayi are most commonly targeted in the Eastern Cape and are found at depths of up to 40 m. Respondents also indicated that there may be a seasonal onshore (Summer/Winter) and offshore (Summer/Winter) migration with year-round spawning and a peak in November, December and January. The incorporation of spearfishers into the data collection, both through the collection of specimens and their FEK, was beneficial to this study. Besides providing samples from a broader geographical range than the primary collection area, the collaboration with spearfishers has promoted the inclusion of this group into the management system. The findings of this study also suggest that FEK data can be more reliable if the concept of recreational specialisation is incorporated into data collection. While the FEK suggested that the population was stable, a stock assessment is necessary to fully understand the population status and implement management strategies. Nevertheless, the key life history characteristics (slow growth and late maturation) observed in this study are characteristic of species that is vulnerable to overexploitation, and thus the precautionary approach should be applied. The reproductive information collected in this study has provided information for the implementation of an appropriate size limit regulation for Oplegnathus conwayi. Here, a minimum size limit of 400 mm TL, which corresponds approximately with the length-at-50% maturity of 330 mm FL, would be appropriate to allow fish to mature and spawn, and reduce the likelihood of recruitment overfishing. Reduction in the bag limit from five to two fish per person per day may also be appropriate as a precautionary measure until a stock assessment has been completed. Finally, the incorporation of stakeholder into biological collection and the use of FEK may be a useful approach for other data deficient species and in countries with limited resources for ecological research. , Thesis (MSc) -- Faculty of Science, Ichthyology and Fisheries Science, 2021
- Full Text:
- Date Issued: 2021-10-29
A framework to improve social media as a communication tool in technical vocational education and training colleges in South Africa: a case of twitter.
- Nyamanhare, Sangudzayi Innocent
- Authors: Nyamanhare, Sangudzayi Innocent
- Date: 2021-02
- Subjects: Social media , Education, Higher , Universities and colleges
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/20495 , vital:46008
- Description: South Africa uses social media as a communication tool. The use of Twitter as a communication tool in Technical Vocational Education and Training Colleges (TVET) in South Africa is a crucial factor for efficient and effective communication between TVET College administration and stakeholders such as prospective students, students, prospective employers, prospective employees and the Twitter community which follow various Twitter accounts. Literature has found that TVET Colleges use Twitter in a monologic manner which promotes one-way information flow. Twitter is also used in a limited fashion and within silos within TVET Colleges that have incorporated this social media platform into their communication strategy. The main purpose of this research study was to develop a framework to improve social media as a communication tool in TVET Colleges in South Africa. The Social Media-Integration- Theory-Model was used as the theoretical framework to evaluate the use of Twitter in TVET Colleges in South Africa, thus enabling the development of critical success factors to improve the use of social media as a communication tool. The Interpretivist paradigm and qualitative research approach was chosen for this study. Netnography was used to collect the online data from Twitter that was analysed in the study. Data was collected from 36 TVET Colleges in South Africa that have a Twitter account over a one-year period (April 2019 – March 2020). After the data collection, content and thematic analysis were used to analyse the date. The study developed a framework from the analyses of tweets which incorporated the four constructs from the Social-Media-Integration-Theory-Model. The study also developed five critical success factors, namely, procuring and maintaining of ICT infrastructure; implementing a policy that guide the use of social networks for communication purposes in TVET Colleges; raising awareness on the use of Twitter as a tool for communication; intensive training to manage administration of Twitter accounts and appointing champions to promote Twitter as a communication tool in TVET Colleges. , Thesis (MCom) (Information Systems)-- University of Fort Hare, 2021
- Full Text:
- Date Issued: 2021-02
- Authors: Nyamanhare, Sangudzayi Innocent
- Date: 2021-02
- Subjects: Social media , Education, Higher , Universities and colleges
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/20495 , vital:46008
- Description: South Africa uses social media as a communication tool. The use of Twitter as a communication tool in Technical Vocational Education and Training Colleges (TVET) in South Africa is a crucial factor for efficient and effective communication between TVET College administration and stakeholders such as prospective students, students, prospective employers, prospective employees and the Twitter community which follow various Twitter accounts. Literature has found that TVET Colleges use Twitter in a monologic manner which promotes one-way information flow. Twitter is also used in a limited fashion and within silos within TVET Colleges that have incorporated this social media platform into their communication strategy. The main purpose of this research study was to develop a framework to improve social media as a communication tool in TVET Colleges in South Africa. The Social Media-Integration- Theory-Model was used as the theoretical framework to evaluate the use of Twitter in TVET Colleges in South Africa, thus enabling the development of critical success factors to improve the use of social media as a communication tool. The Interpretivist paradigm and qualitative research approach was chosen for this study. Netnography was used to collect the online data from Twitter that was analysed in the study. Data was collected from 36 TVET Colleges in South Africa that have a Twitter account over a one-year period (April 2019 – March 2020). After the data collection, content and thematic analysis were used to analyse the date. The study developed a framework from the analyses of tweets which incorporated the four constructs from the Social-Media-Integration-Theory-Model. The study also developed five critical success factors, namely, procuring and maintaining of ICT infrastructure; implementing a policy that guide the use of social networks for communication purposes in TVET Colleges; raising awareness on the use of Twitter as a tool for communication; intensive training to manage administration of Twitter accounts and appointing champions to promote Twitter as a communication tool in TVET Colleges. , Thesis (MCom) (Information Systems)-- University of Fort Hare, 2021
- Full Text:
- Date Issued: 2021-02
A green approach for the synthesis of symmetrical and unsymmetrical 1,2,4,5-tetraoxanes as anti-protozoal agents
- Authors: Cossa, Teresa Manuel
- Date: 2021-10-29
- Subjects: Uncatalogued
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/192786 , vital:45264
- Description: Thesis (PhD) -- Faculty of Science, Chemistry, 2021
- Full Text:
- Date Issued: 2021-10-29
- Authors: Cossa, Teresa Manuel
- Date: 2021-10-29
- Subjects: Uncatalogued
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/192786 , vital:45264
- Description: Thesis (PhD) -- Faculty of Science, Chemistry, 2021
- Full Text:
- Date Issued: 2021-10-29
Adolescent sexual reproductive health and rights in the Alice area, Eastern Cape Province of South Africa
- Authors: Moko, Zukhanye
- Date: 2021-02
- Subjects: Reproductive health , Right to health , HIV infections
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/20676 , vital:46423
- Description: Sexual Reproductive Health (SRH) is a significant aspect of adolescent’s growth. Adolescents particularly girls face the risk of exposure to Human Immunodeficiency Virus (HIV), Sexually Transmitted Diseases (STDs), child marriages, high rates of unwanted pregnancy and the risk of those pregnancies can lead to unsafe abortion. In South Africa, considerable progress has been made in achieving improved access to Sexual Reproductive Health and Rights (SRHR) among the general population, however, some factors influencing SRHR of adolescents and young people have been slow to achieve. The study aims to investigate factors influencing Sexual Reproductive Health and Rights of adolescents in Alice, which is located in the Eastern Cape Province of South Africa. The Social-Ecological Model was considered appropriate for this study as it provides a comprehensive understanding of the multiple and interacting determinants of Sexual Reproductive Health and Rights. A qualitative methodology was adopted, involving focus groups with high school learners, in-depth interviews with institutional actors (Department of Health, Basic Education and Social Development), and participant observations. The study reveals that adolescents’ have access to Sexual Reproductive Health services from healthcare centres but only a few utilize or access them due to barriers such as the geographical location, denial and judgement about young people's sexuality limits their access to comprehensive knowledge to protect and promote their Sexual and Reproductive Health. The findings show that the adolescents who were most affected by Sexual Reproductive Health and Rights challenges were those from deep rural areas. They had minimal information/education compared to those residing in areas close to the town of Alice and major roads. Multi-sectoral interventions empowering adolescents and young people to exercise their rights to optimize SRHR service yield better results. , Thesis (MSc) -- Faculty of Science & Agriculture, 2021
- Full Text:
- Date Issued: 2021-02
- Authors: Moko, Zukhanye
- Date: 2021-02
- Subjects: Reproductive health , Right to health , HIV infections
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/20676 , vital:46423
- Description: Sexual Reproductive Health (SRH) is a significant aspect of adolescent’s growth. Adolescents particularly girls face the risk of exposure to Human Immunodeficiency Virus (HIV), Sexually Transmitted Diseases (STDs), child marriages, high rates of unwanted pregnancy and the risk of those pregnancies can lead to unsafe abortion. In South Africa, considerable progress has been made in achieving improved access to Sexual Reproductive Health and Rights (SRHR) among the general population, however, some factors influencing SRHR of adolescents and young people have been slow to achieve. The study aims to investigate factors influencing Sexual Reproductive Health and Rights of adolescents in Alice, which is located in the Eastern Cape Province of South Africa. The Social-Ecological Model was considered appropriate for this study as it provides a comprehensive understanding of the multiple and interacting determinants of Sexual Reproductive Health and Rights. A qualitative methodology was adopted, involving focus groups with high school learners, in-depth interviews with institutional actors (Department of Health, Basic Education and Social Development), and participant observations. The study reveals that adolescents’ have access to Sexual Reproductive Health services from healthcare centres but only a few utilize or access them due to barriers such as the geographical location, denial and judgement about young people's sexuality limits their access to comprehensive knowledge to protect and promote their Sexual and Reproductive Health. The findings show that the adolescents who were most affected by Sexual Reproductive Health and Rights challenges were those from deep rural areas. They had minimal information/education compared to those residing in areas close to the town of Alice and major roads. Multi-sectoral interventions empowering adolescents and young people to exercise their rights to optimize SRHR service yield better results. , Thesis (MSc) -- Faculty of Science & Agriculture, 2021
- Full Text:
- Date Issued: 2021-02
Agro-morphological characterization and investigations into the response of yellow Quality Protein Maize (QPM) genotypes to low soil pH
- Authors: Bobotyana, Simthandile
- Date: 2021-04
- Subjects: Corn as food , Plants--Drought tolerance
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/20528 , vital:46087
- Description: Maize (Zea mays L) is an essential food grain crop in South Africa and is mainly grown under rainfed conditions by small-scale farmers. Quality Protein Maize (QPM) contains a higher level of two essential amino acids, tryptophan, and lysine when equated to normal maize. Therefore, the QPM in communities is a vital cereal where maize is a staple crop. Among the significant abiotic stresses that adversely affect maize productivity, such as soil fertility. Low soil pH or soil acidity results in nutrient deficiencies, as well as the toxicity of minerals such as manganese (Mn), aluminium (Al), and iron (Fe). The objectives of the study were to: (1) Characterize yellow QPM inbred lines and testcross hybrids for agro-morphological variability under optimum conditions, (2) Determine the response of QPM inbred lines and testcross hybrids to Al toxicity, and (3) Estimate the combining ability of QPM genotypes for the tolerance to Al toxicity. The laboratory assessment for tolerance to Al toxicity revealed a negative relationship between relative root growth RRG and hematoxylin staining; among the inbred lines, the genotype 8Y, 17Y, and 7Y had the highest RRG and net root growth (NRG) values and exhibited the highest tolerance to Al tolerance with the least hematoxylin staining. Inbred lines 12Y, 16Y, 19Y, 2Y, 20Y, 24Y, 30Y, 27Y, 34Y, 4Y, and 11Y were moderately tolerant. On the other hand, inbred lines 13Y, 18Y, and QSY5 had the least RRG were susceptible. Forty-four testcross hybrids were generated by crossing 22 QPM inbred lines with two open-pollinated variety (OPV) testers. These hybrids were evaluated together with five checks for different agronomic traits. The hybrids were planted in the summer season of 2017/18 and 2018/19 under rain-fed conditions 7 x 7 alpha lattice design was used. The significant variations among the genotypes for grain yield and most other agronomic traits under optimum, acidic conditions and across environments on combined analysis of variance. The hybrid was 14Y x NC (3.22 t/ha), followed by QSY5 x NC (3.02 t/ha) showed the highest yielding. The mean plant height was 226.23 cm, with ranges 197.60 to 254.85cm. The number of kernels per ear was 35, with a range from 29.45 to 40.25. Conversely, the mean ear length was 19.30 cm with a range of 17.65 to 20.95 cm, and the mean ear diameter ranged from 13,50 to 16,05 cm. The highest yielding hybrid, according to ranking, was 14Y x NC (2,93t/ha), which was ranked number 3, followed by 3Y x NC (2,83 t/ha), which was ranked number 4. Twenty-two yellow QPM inbred lines were evaluated for agro-morphological characteristics. A randomized complete block design with three replicates was used under acidic and normal soil conditions at two locations. The mean performance of inbred lines for grain yield ranged from 1.6 t/ha to 3.1 t/ha under optimum conditions, whereas it ranged from 1.1.t/ha to 1.7 t/ha under an acidic environment. The highest grain yielding genotypes under the optimum environment were 14Y, 7Y, and QSY5, while, in the acidic environment, the highest yielders were 3Y, QSY5, and 17Y. The lowest grain yielder under the optimum environment was 16Y at 1.5 t/ha, whereas 6Y, 7Y, 8Y, and 29Y were the most moderate yielders under the acidic environment. Grain yield displayed positive and significant (p<0,05) correlation with ear height (0.59), plant height (0.55), leaf length (0.18), number of leaves (0.37), number of ears per plot (0,54), number of kernels per row, number of rows per ear and thousand kernel weight. Combined ANOVA revealed that the environment effect was significant for all traits except the number of rows per ear and the number of ears in both environments. A total of 71 genotypes (22 inbred lines, forty-four single crosses, and five checks) were evaluated using a 7 x 7 alpha lattice design with two replications in combining ability. Across environments, the analysis showed a mean grain yield record of hybrids that ranged from 1.78 t/ha to 3.42 t/ha. Combined analysis showed only about 4 percent of the 44 hybrids had better grain yield than hybrid checks, whereas about 11 percent of the 44 hybrids had higher grain yield than two of the five hybrid checks. The highest yielding hybrid was 14Y x NC followed by QSY5 x NC. The Mid-parent heterosis (MPH) for grain yield ranged from -32.70 for 11YxObat to 16.50 percent for 14YxNC among the top-yielding genotypes. The highest positive mid-parent heterosis (MPH) for grain yield was observed in hybrid 14YxNC followed by QSY9xNC, QSY5xOBAT, 3YxNC, 13YxNC and 4YxOBAT, while the remaining hybrids exhibited negative estimates. Inbred lines' proportional contributions to the total variances were much higher than the testers for all traits. Whereas the inbred lines' proportional contribution was lower than the interaction of line x tester except on the number of ears which displayed the highest estimates of variances due to SCA effects, significant variation was observed. The GCA effects on grain yield in both environments generally showed no significant difference among inbred lines except for inbred lines such as QSY5 and 34Y but were positive. The selected crosses showed significant SCA effects in a few agronomic yield-related traits in the combined analysis. Among the hybrids, the only crosses that showed significant and positive SCA effects for grain yield were 25YxNC under optimum and 34YxObat under acidic environment. The inbred lines were assessed for tolerance to Al toxicity under laboratory conditions. Overall, the study identified soil acidity tolerant QPM inbred lines with an excellent combining ability for high-yielding QPM test hybrids, grain yield, and related traits. , Thesis (MSc) (Agriculture, Crop Science) -- University of Fort Hare, 2021
- Full Text:
- Date Issued: 2021-04
- Authors: Bobotyana, Simthandile
- Date: 2021-04
- Subjects: Corn as food , Plants--Drought tolerance
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/20528 , vital:46087
- Description: Maize (Zea mays L) is an essential food grain crop in South Africa and is mainly grown under rainfed conditions by small-scale farmers. Quality Protein Maize (QPM) contains a higher level of two essential amino acids, tryptophan, and lysine when equated to normal maize. Therefore, the QPM in communities is a vital cereal where maize is a staple crop. Among the significant abiotic stresses that adversely affect maize productivity, such as soil fertility. Low soil pH or soil acidity results in nutrient deficiencies, as well as the toxicity of minerals such as manganese (Mn), aluminium (Al), and iron (Fe). The objectives of the study were to: (1) Characterize yellow QPM inbred lines and testcross hybrids for agro-morphological variability under optimum conditions, (2) Determine the response of QPM inbred lines and testcross hybrids to Al toxicity, and (3) Estimate the combining ability of QPM genotypes for the tolerance to Al toxicity. The laboratory assessment for tolerance to Al toxicity revealed a negative relationship between relative root growth RRG and hematoxylin staining; among the inbred lines, the genotype 8Y, 17Y, and 7Y had the highest RRG and net root growth (NRG) values and exhibited the highest tolerance to Al tolerance with the least hematoxylin staining. Inbred lines 12Y, 16Y, 19Y, 2Y, 20Y, 24Y, 30Y, 27Y, 34Y, 4Y, and 11Y were moderately tolerant. On the other hand, inbred lines 13Y, 18Y, and QSY5 had the least RRG were susceptible. Forty-four testcross hybrids were generated by crossing 22 QPM inbred lines with two open-pollinated variety (OPV) testers. These hybrids were evaluated together with five checks for different agronomic traits. The hybrids were planted in the summer season of 2017/18 and 2018/19 under rain-fed conditions 7 x 7 alpha lattice design was used. The significant variations among the genotypes for grain yield and most other agronomic traits under optimum, acidic conditions and across environments on combined analysis of variance. The hybrid was 14Y x NC (3.22 t/ha), followed by QSY5 x NC (3.02 t/ha) showed the highest yielding. The mean plant height was 226.23 cm, with ranges 197.60 to 254.85cm. The number of kernels per ear was 35, with a range from 29.45 to 40.25. Conversely, the mean ear length was 19.30 cm with a range of 17.65 to 20.95 cm, and the mean ear diameter ranged from 13,50 to 16,05 cm. The highest yielding hybrid, according to ranking, was 14Y x NC (2,93t/ha), which was ranked number 3, followed by 3Y x NC (2,83 t/ha), which was ranked number 4. Twenty-two yellow QPM inbred lines were evaluated for agro-morphological characteristics. A randomized complete block design with three replicates was used under acidic and normal soil conditions at two locations. The mean performance of inbred lines for grain yield ranged from 1.6 t/ha to 3.1 t/ha under optimum conditions, whereas it ranged from 1.1.t/ha to 1.7 t/ha under an acidic environment. The highest grain yielding genotypes under the optimum environment were 14Y, 7Y, and QSY5, while, in the acidic environment, the highest yielders were 3Y, QSY5, and 17Y. The lowest grain yielder under the optimum environment was 16Y at 1.5 t/ha, whereas 6Y, 7Y, 8Y, and 29Y were the most moderate yielders under the acidic environment. Grain yield displayed positive and significant (p<0,05) correlation with ear height (0.59), plant height (0.55), leaf length (0.18), number of leaves (0.37), number of ears per plot (0,54), number of kernels per row, number of rows per ear and thousand kernel weight. Combined ANOVA revealed that the environment effect was significant for all traits except the number of rows per ear and the number of ears in both environments. A total of 71 genotypes (22 inbred lines, forty-four single crosses, and five checks) were evaluated using a 7 x 7 alpha lattice design with two replications in combining ability. Across environments, the analysis showed a mean grain yield record of hybrids that ranged from 1.78 t/ha to 3.42 t/ha. Combined analysis showed only about 4 percent of the 44 hybrids had better grain yield than hybrid checks, whereas about 11 percent of the 44 hybrids had higher grain yield than two of the five hybrid checks. The highest yielding hybrid was 14Y x NC followed by QSY5 x NC. The Mid-parent heterosis (MPH) for grain yield ranged from -32.70 for 11YxObat to 16.50 percent for 14YxNC among the top-yielding genotypes. The highest positive mid-parent heterosis (MPH) for grain yield was observed in hybrid 14YxNC followed by QSY9xNC, QSY5xOBAT, 3YxNC, 13YxNC and 4YxOBAT, while the remaining hybrids exhibited negative estimates. Inbred lines' proportional contributions to the total variances were much higher than the testers for all traits. Whereas the inbred lines' proportional contribution was lower than the interaction of line x tester except on the number of ears which displayed the highest estimates of variances due to SCA effects, significant variation was observed. The GCA effects on grain yield in both environments generally showed no significant difference among inbred lines except for inbred lines such as QSY5 and 34Y but were positive. The selected crosses showed significant SCA effects in a few agronomic yield-related traits in the combined analysis. Among the hybrids, the only crosses that showed significant and positive SCA effects for grain yield were 25YxNC under optimum and 34YxObat under acidic environment. The inbred lines were assessed for tolerance to Al toxicity under laboratory conditions. Overall, the study identified soil acidity tolerant QPM inbred lines with an excellent combining ability for high-yielding QPM test hybrids, grain yield, and related traits. , Thesis (MSc) (Agriculture, Crop Science) -- University of Fort Hare, 2021
- Full Text:
- Date Issued: 2021-04
An analysis of students’ constructions of the ‘fees must Fall’ movement at an historically black university
- Authors: Chandler, Kelly Jean
- Date: 2021-02
- Subjects: Student movements , College students--Political activity , Student protesters
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/21058 , vital:46939
- Description: The ‘Fees Must Fall’ movement which occured in 2015 and 2016 was a major national event which affected most higher education institutions in South Africa. This research considers the constructions of the ‘Fees Must Fall’ movement at an historically black university, namely, the University of Fort Hare. Furthermore, the research analyzes how students are positioned in their constructions in relation to the movement. The study aims to contribute to the understanding of the lived experiences of student activists in the 2015 and 2016 ‘Fees Must Fall’ movement at the University of Fort Hare. The data collection method used was a convenience sampling method with seven participants interviewed. Making use of the guidelines of a Foucauldian Discourse Analysis, four primary discourses were identified from the data collected: coercion discourses; fear discourses; financial discourses; and meritocracy discourses. The positions of students were varied and consisted of both agentic and submissive positions, with the student representative council frequently being positioned dominantly. The theoretical framework also included Michel Foucault’s theories of governmentality and biopower which contributed significantly to the understandings of institutional power in the university context. The research is conducted against ethical backdrop of the philosophies and guidelines of postcolonial psychology. The broader context of South Africa is observed and discussed, specifically recognizing the legacy of apartheid and other historical antecedents such as colonization. The issues of transformation, institutional racism, and decolonization are placed at the forefront of this research endeavour. , Thesis (MSoc Sci) (Psychology) - - University of Fort Hare, 2021
- Full Text:
- Date Issued: 2021-02
- Authors: Chandler, Kelly Jean
- Date: 2021-02
- Subjects: Student movements , College students--Political activity , Student protesters
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/21058 , vital:46939
- Description: The ‘Fees Must Fall’ movement which occured in 2015 and 2016 was a major national event which affected most higher education institutions in South Africa. This research considers the constructions of the ‘Fees Must Fall’ movement at an historically black university, namely, the University of Fort Hare. Furthermore, the research analyzes how students are positioned in their constructions in relation to the movement. The study aims to contribute to the understanding of the lived experiences of student activists in the 2015 and 2016 ‘Fees Must Fall’ movement at the University of Fort Hare. The data collection method used was a convenience sampling method with seven participants interviewed. Making use of the guidelines of a Foucauldian Discourse Analysis, four primary discourses were identified from the data collected: coercion discourses; fear discourses; financial discourses; and meritocracy discourses. The positions of students were varied and consisted of both agentic and submissive positions, with the student representative council frequently being positioned dominantly. The theoretical framework also included Michel Foucault’s theories of governmentality and biopower which contributed significantly to the understandings of institutional power in the university context. The research is conducted against ethical backdrop of the philosophies and guidelines of postcolonial psychology. The broader context of South Africa is observed and discussed, specifically recognizing the legacy of apartheid and other historical antecedents such as colonization. The issues of transformation, institutional racism, and decolonization are placed at the forefront of this research endeavour. , Thesis (MSoc Sci) (Psychology) - - University of Fort Hare, 2021
- Full Text:
- Date Issued: 2021-02
An appraisal of the East London Industrial Development Zone’s role in local innovation, entrepreneurship, and industrial development
- Authors: Masiwa, George Bonginkosi
- Date: 2021-02
- Subjects: Industrialization , Economic development , South Africa -- Economic conditions
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/21213 , vital:47406
- Description: This study focuses on the East London Industrial Development Zone (ELIDZ) in South Africa. The ELIDZ strategy came as a response to the need for a robust catalyst for sustainable regional economic development, industrial diversification and to create meaningful employment opportunities in the country. It was supposed to provide customised solutions for various industries including automotive, agro-processing and aqua-culture. However, an Industrial Development Zone should promote innovati on and entrepreneurship to stimulate economic growth and global competitiveness. Economic stagnation, joblessness and inequality continue to be a reality for the previously marginalised groups after 16 years of the ELIDZ despite significant investments in the automotive sector, the growth of companies that supply Mercedes Benz with parts and the establishment and growth of innovative start-up companies at the ELIDZ Science and Technology Park (STP). Massive joblessness, poverty and economic stagnation had followed the collapse of the old industrial parks. The ELIDZ strategy of industrial development came as a response to the demise of the old parks and was meant to become the main vehicle for job creation, local innovation and global competitiveness. This study therefore investigated the extent to which innovation and entrepreneurship have fared in driving sustainable local economic development and how they have impacted jobs at the ELIDZ and within the East London community. The study was qualitative in nature and employed the non-probability sampling technique. In-depth semi-structured interviews were conducted with key informants that included Industrialists, Business Executives that were tenants at the ELIDZ, the Buffalo City Municipal Metro and community members with knowledge of and association with the ELIDZ. This was augmented by desktop and observational data. It was found that innovation and entrepreneurship was still a fairly new phenomenon at the ELIDZ and their flagships had the vision but were not yet driving sustainable local economic development to a large extent. The model lacks adequate diversification as most of the innovation projects are in the renewable energy and information communication spaces. Very few have made it to mass production with downstream industry employment creation for plumbers, artisans and marketers involved in the supply, distribution, instalment and maintenance of the Hotspot and Thin-film solar panels. New industrialists like YEKANI Technologies and Manufacturing and KGI Holdings, already employ some people and have the vision to employ thousands more of young people. The main innovation and entrepreneurship projects of the ELIDZ have had some impact at the grassroots level even though it is still limited. Too few jobs have been created compared to the old industrial parks model. The ELIDZ is therefore playing an important (albeit limited) role as a local employment creator, even though it has not revitalised the Eastern Cape manufacturing landscape. Due to its highly technology driven and specialised skills nature, the ELIDZ model is benefiting the few and therefore has not yet been an effective instrument to resolve the disturbing levels of inequality, poverty and unemployment, that underlie racial, class and gender dynamics in East London. The study concluded that innovation and entrepreneurship projects at the ELIDZ were contributing towards driving sustainable local economic development to some degree. However, due to its narrow industrial focus and highly technical and specialised skills driven business model, it excludes most historically disadvantaged communities and the local academic institutions need to do more to produce the skills relevant to support local innovation and local industrial development in a time when economies rely more on intellectual capabilities rather than natural resources. , Thesis (PhD) -- Faculty of Social Sciences and Humanities, 2021
- Full Text:
- Date Issued: 2021-02
- Authors: Masiwa, George Bonginkosi
- Date: 2021-02
- Subjects: Industrialization , Economic development , South Africa -- Economic conditions
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/21213 , vital:47406
- Description: This study focuses on the East London Industrial Development Zone (ELIDZ) in South Africa. The ELIDZ strategy came as a response to the need for a robust catalyst for sustainable regional economic development, industrial diversification and to create meaningful employment opportunities in the country. It was supposed to provide customised solutions for various industries including automotive, agro-processing and aqua-culture. However, an Industrial Development Zone should promote innovati on and entrepreneurship to stimulate economic growth and global competitiveness. Economic stagnation, joblessness and inequality continue to be a reality for the previously marginalised groups after 16 years of the ELIDZ despite significant investments in the automotive sector, the growth of companies that supply Mercedes Benz with parts and the establishment and growth of innovative start-up companies at the ELIDZ Science and Technology Park (STP). Massive joblessness, poverty and economic stagnation had followed the collapse of the old industrial parks. The ELIDZ strategy of industrial development came as a response to the demise of the old parks and was meant to become the main vehicle for job creation, local innovation and global competitiveness. This study therefore investigated the extent to which innovation and entrepreneurship have fared in driving sustainable local economic development and how they have impacted jobs at the ELIDZ and within the East London community. The study was qualitative in nature and employed the non-probability sampling technique. In-depth semi-structured interviews were conducted with key informants that included Industrialists, Business Executives that were tenants at the ELIDZ, the Buffalo City Municipal Metro and community members with knowledge of and association with the ELIDZ. This was augmented by desktop and observational data. It was found that innovation and entrepreneurship was still a fairly new phenomenon at the ELIDZ and their flagships had the vision but were not yet driving sustainable local economic development to a large extent. The model lacks adequate diversification as most of the innovation projects are in the renewable energy and information communication spaces. Very few have made it to mass production with downstream industry employment creation for plumbers, artisans and marketers involved in the supply, distribution, instalment and maintenance of the Hotspot and Thin-film solar panels. New industrialists like YEKANI Technologies and Manufacturing and KGI Holdings, already employ some people and have the vision to employ thousands more of young people. The main innovation and entrepreneurship projects of the ELIDZ have had some impact at the grassroots level even though it is still limited. Too few jobs have been created compared to the old industrial parks model. The ELIDZ is therefore playing an important (albeit limited) role as a local employment creator, even though it has not revitalised the Eastern Cape manufacturing landscape. Due to its highly technology driven and specialised skills nature, the ELIDZ model is benefiting the few and therefore has not yet been an effective instrument to resolve the disturbing levels of inequality, poverty and unemployment, that underlie racial, class and gender dynamics in East London. The study concluded that innovation and entrepreneurship projects at the ELIDZ were contributing towards driving sustainable local economic development to some degree. However, due to its narrow industrial focus and highly technical and specialised skills driven business model, it excludes most historically disadvantaged communities and the local academic institutions need to do more to produce the skills relevant to support local innovation and local industrial development in a time when economies rely more on intellectual capabilities rather than natural resources. , Thesis (PhD) -- Faculty of Social Sciences and Humanities, 2021
- Full Text:
- Date Issued: 2021-02
An exploratory analysis of the challenges faced by police in combating mob justice: a case study of Gqeberha
- Loqani Anelisa https://orcid.org/0000-0001-9944-5947
- Authors: Loqani Anelisa https://orcid.org/0000-0001-9944-5947
- Date: 2021-02
- Subjects: Vigilance committees , Criminal justice, Administration of
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/22000 , vital:51928
- Description: Mob justice is a major issue that will continue to occur as long as criminal activities exist. In South Africa, mob justice has become a major challenge for the government, particularly the South African Police Service as well as the society at large. The South African Police Service (SAPS) has partnered with all relevant role-players in the fight against mob justice and other community problems which threaten the safety of inhabitants. However, concerted efforts have also been made by the government to assist the SAPS to address the occurrence and re-occurrence of mob justice by introducing strategies such as visible policing but the problem seems to persist. The study, thus, analyzed the challenges faced by the police that lead to their ineffectiveness in eliminating mob justice. This thesis draws from two theories, namely Structural Violence theory pioneered by Galtung (1969) and Just World Theory (JWT) by Adelstein (1999) to explore the challenges faced by the police in Gqeberha. This study was conducted in the Eastern Cape Province, in Gqeberha within four townships, namely Kwadwesi, Kwazakhele, Motherwell, and New Brighton. The findings gathered by utilizing Focus Group Interviews (FGIs) and semi-structured interviews with a total number of forty-eight (48) respondents comprising of sixteen (16) SAPS members, eight (08) Community Policing Forum (CPF) representatives, four (04) community leaders and twenty (20) community members. This is a qualitative research project in which participants were chosen using purposive sampling. Participants were chosen based on their knowledge and experiences relating to the phenomena being explored. The aim was to gain an in-depth understanding of the challenges encountered by the police in combating mob justice to discover some techniques to improve and strengthen the police service to make communities safer. To analyse the data thematic analysis was utilized. The results of the study indicate that an increase in mob justice in Gqeberha has been reported to be a result of the high rate of crime. However, the fact that people know they will not get arrested for participating in mob justice is one of the concerns that have led to an escalation in mob justice. The study demonstrates that in most incidents the community members have once witnessed in their respective areas, the victims were killed while few survived and in all those incidents only a few arrests were made and in those few arrests, no convictions were made. Based on this issue of arrests, results indicate that the SAPS members are confronting some difficulties in identifying and arresting the perpetrators of mob justice. The reluctance of community members to report mob justice cases and to provide information was found to be the main challenge faced by the police in combating mob justice in Motherwell Cluster precincts. These challenges have been reported to negatively affect police work performance. Further analysis revealed that CPF, community members and community leaders as part of stakeholders who are working together with SAPS are also facing some challenges in addressing this issue of mob justice. The results also indicate that mob justice does not only harm members of the community who are subjected to these occurrences, but also the police, the victims and the perpetrators themselves. Evidence-based techniques to help eradicate mob justice incidents were developed in response to this problem of mob justice. The participants suggested that the police must be provided with adequate manpower, more community patrols and vehicles. It is believed that if the police could act in time and arrest the suspected criminals, a large number of people would be rescued from being killed in mob justice. The respondents also indicated that the police must build good relations with the communities by being visible and transparent in communities. Furthermore, the SAPS participants alluded that when people are sentenced, a community engagement needs to be conducted before those people are released outside as parolees. Other respondents mentioned the issue of education, proposing that the Criminal Justice System (CJS) should frequently conduct awareness campaigns, imbizos and public meetings to teach and inform people about its operations. , Thesis (PhD) -- Faculty of Social Sciences and Humanities, 2021
- Full Text:
- Date Issued: 2021-02
- Authors: Loqani Anelisa https://orcid.org/0000-0001-9944-5947
- Date: 2021-02
- Subjects: Vigilance committees , Criminal justice, Administration of
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/22000 , vital:51928
- Description: Mob justice is a major issue that will continue to occur as long as criminal activities exist. In South Africa, mob justice has become a major challenge for the government, particularly the South African Police Service as well as the society at large. The South African Police Service (SAPS) has partnered with all relevant role-players in the fight against mob justice and other community problems which threaten the safety of inhabitants. However, concerted efforts have also been made by the government to assist the SAPS to address the occurrence and re-occurrence of mob justice by introducing strategies such as visible policing but the problem seems to persist. The study, thus, analyzed the challenges faced by the police that lead to their ineffectiveness in eliminating mob justice. This thesis draws from two theories, namely Structural Violence theory pioneered by Galtung (1969) and Just World Theory (JWT) by Adelstein (1999) to explore the challenges faced by the police in Gqeberha. This study was conducted in the Eastern Cape Province, in Gqeberha within four townships, namely Kwadwesi, Kwazakhele, Motherwell, and New Brighton. The findings gathered by utilizing Focus Group Interviews (FGIs) and semi-structured interviews with a total number of forty-eight (48) respondents comprising of sixteen (16) SAPS members, eight (08) Community Policing Forum (CPF) representatives, four (04) community leaders and twenty (20) community members. This is a qualitative research project in which participants were chosen using purposive sampling. Participants were chosen based on their knowledge and experiences relating to the phenomena being explored. The aim was to gain an in-depth understanding of the challenges encountered by the police in combating mob justice to discover some techniques to improve and strengthen the police service to make communities safer. To analyse the data thematic analysis was utilized. The results of the study indicate that an increase in mob justice in Gqeberha has been reported to be a result of the high rate of crime. However, the fact that people know they will not get arrested for participating in mob justice is one of the concerns that have led to an escalation in mob justice. The study demonstrates that in most incidents the community members have once witnessed in their respective areas, the victims were killed while few survived and in all those incidents only a few arrests were made and in those few arrests, no convictions were made. Based on this issue of arrests, results indicate that the SAPS members are confronting some difficulties in identifying and arresting the perpetrators of mob justice. The reluctance of community members to report mob justice cases and to provide information was found to be the main challenge faced by the police in combating mob justice in Motherwell Cluster precincts. These challenges have been reported to negatively affect police work performance. Further analysis revealed that CPF, community members and community leaders as part of stakeholders who are working together with SAPS are also facing some challenges in addressing this issue of mob justice. The results also indicate that mob justice does not only harm members of the community who are subjected to these occurrences, but also the police, the victims and the perpetrators themselves. Evidence-based techniques to help eradicate mob justice incidents were developed in response to this problem of mob justice. The participants suggested that the police must be provided with adequate manpower, more community patrols and vehicles. It is believed that if the police could act in time and arrest the suspected criminals, a large number of people would be rescued from being killed in mob justice. The respondents also indicated that the police must build good relations with the communities by being visible and transparent in communities. Furthermore, the SAPS participants alluded that when people are sentenced, a community engagement needs to be conducted before those people are released outside as parolees. Other respondents mentioned the issue of education, proposing that the Criminal Justice System (CJS) should frequently conduct awareness campaigns, imbizos and public meetings to teach and inform people about its operations. , Thesis (PhD) -- Faculty of Social Sciences and Humanities, 2021
- Full Text:
- Date Issued: 2021-02
An investigation into yeast-baculovirus synergism for the improved control of Thaumatotibia leucotreta, an economically important pest of citrus
- Authors: Van der Merwe, Marcél
- Date: 2021-10-29
- Subjects: Baculoviruses , Cryptophlebia leucotreta , Yeast , Natural pesticides , Citrus Diseases and pests , Biological pest control agents , Pests Integrated control , Thaumatotibia leucotreta
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/191236 , vital:45073
- Description: A mutualistic association between Cydia pomonella and yeasts belonging to the genus Metschnikowia has previously been demonstrated. Larval feeding galleries inoculated with M. andauensis, reduced larval mortality and enhanced larval development. Additionally, adult C. pomonella female oviposition preference was also shown to be influenced by the volatiles produced by M. andauensis. This mutualistic relationship was manipulated for biological control purposes, by combining M. pulcherrima with the baculovirus Cydia pomonella granulovirus. The combination of M. pulcherrima with brown cane sugar and CpGV in laboratory assays and field trials resulted in a significant increase in larval mortality. A similar observation was made when M. pulcherrima was substituted for Saccharomyces cerevisiae. This indicates that yeasts harbour the potential for use in biological control, especially when combined with other well-established biocontrol methods. Thaumatotibia leucotreta is a phytophagous insect endemic to southern Africa. It is highly significant to the South African citrus industry due to its classification as a phytosanitary pest by most international markets. An integrated pest management programme has been implemented to control T. leucotreta. The baculovirus Cryptophlebia leucotreta granulovirus forms one component of this programme and is highly effective. In this study, we proposed to determine which yeast species occur naturally in the gut of T. leucotreta larvae and to examine whether any of the isolated yeast species, when combined with the CrleGV-SA, enhance its effectiveness. Firstly, Navel oranges infested with T. leucotreta larvae were collected from geographically distinct citrus-producing regions across South Africa. This led to the isolation and identification of six yeast species from the gut of T. leucotreta larvae via PCR amplification and sequencing of the internal transcribed spacer region and D1/D2 domain of the large subunit. Six yeast species were identified, viz. Meyerozyma guilliermondii, Hanseniaspora uvarum, Clavispora lusitaniae, Kluyveromyces marxianus, Pichia kudriavzevii and Pichia kluyveri. Additionally, Saccharomyces cerevisiae was included as a control in all trials due to its commercial availability and use in the artificial diet used to rear T. leucotreta. Secondly, larval development and attraction assays were conducted with the isolated yeast species. Thaumatotibia leucotreta larvae that fed on Navel oranges inoculated with M. guilliermondii, P. kluyveri, H. uvarum, and S. cerevisiae had accelerated developmental periods and reduced mortality rates. Additionally, it was demonstrated that T. leucotreta neonates were attracted to YPD broth cultures inoculated with P. kluyveri, H. uvarum, P. kudriavzevii and K. marxianus for feeding. Thirdly, oviposition preference assays were conducted with adult T. leucotreta females to determine whether the isolated yeast species influence their egg-laying in two-choice and multiple-choice tests. Navel oranges were inoculated with a specific yeast isolate, and mated adult females were left to oviposit. Meyerozyma guilliermondii, P. kudriavzevii and H. uvarum were shown to influence adult T. leucotreta female oviposition preference in two-choice tests. However, multiple-choice tests using the aforementioned yeast species did not mimic these results. Lastly, a series of detached fruit bioassays were performed to determine the optimal yeast:virus ratio, test all isolated yeast species in combination with CrleGV-SA and to further enhance yeast/virus formulation through the addition of an adjuvant and surfactant. CrleGV-SA was applied at a lethal concentration that would kill 50 % of T. leucotreta larvae. The optimal yeast concentration to use alongside CrleGV-SA was determined. Pichia kluyveri, P. kudriavzevii, K. marxianus and S. cerevisiae in combination with CrleGV-SA increased larval mortality compared to CrleGV-SA alone. The inclusion of molasses and BREAK-THRU® S 240 to P. kudriavzevii and S. cerevisiae plus CrleGV-SA formulations greatly enhanced their efficacy. Additionally, semi-field trials were initiated using P. kudriavzevii and S. cerevisiae, with promising preliminary results being obtained, although more replicates need to be performed. The experiments performed in this study provide a platform for further research into the application of a yeast/virus combination as a novel control and monitoring option for T. leucotreta in the field. , Thesis (PhD) -- Faculty of Science, Biochemistry and Microbiology, 2021
- Full Text:
- Date Issued: 2021-10-29
- Authors: Van der Merwe, Marcél
- Date: 2021-10-29
- Subjects: Baculoviruses , Cryptophlebia leucotreta , Yeast , Natural pesticides , Citrus Diseases and pests , Biological pest control agents , Pests Integrated control , Thaumatotibia leucotreta
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/191236 , vital:45073
- Description: A mutualistic association between Cydia pomonella and yeasts belonging to the genus Metschnikowia has previously been demonstrated. Larval feeding galleries inoculated with M. andauensis, reduced larval mortality and enhanced larval development. Additionally, adult C. pomonella female oviposition preference was also shown to be influenced by the volatiles produced by M. andauensis. This mutualistic relationship was manipulated for biological control purposes, by combining M. pulcherrima with the baculovirus Cydia pomonella granulovirus. The combination of M. pulcherrima with brown cane sugar and CpGV in laboratory assays and field trials resulted in a significant increase in larval mortality. A similar observation was made when M. pulcherrima was substituted for Saccharomyces cerevisiae. This indicates that yeasts harbour the potential for use in biological control, especially when combined with other well-established biocontrol methods. Thaumatotibia leucotreta is a phytophagous insect endemic to southern Africa. It is highly significant to the South African citrus industry due to its classification as a phytosanitary pest by most international markets. An integrated pest management programme has been implemented to control T. leucotreta. The baculovirus Cryptophlebia leucotreta granulovirus forms one component of this programme and is highly effective. In this study, we proposed to determine which yeast species occur naturally in the gut of T. leucotreta larvae and to examine whether any of the isolated yeast species, when combined with the CrleGV-SA, enhance its effectiveness. Firstly, Navel oranges infested with T. leucotreta larvae were collected from geographically distinct citrus-producing regions across South Africa. This led to the isolation and identification of six yeast species from the gut of T. leucotreta larvae via PCR amplification and sequencing of the internal transcribed spacer region and D1/D2 domain of the large subunit. Six yeast species were identified, viz. Meyerozyma guilliermondii, Hanseniaspora uvarum, Clavispora lusitaniae, Kluyveromyces marxianus, Pichia kudriavzevii and Pichia kluyveri. Additionally, Saccharomyces cerevisiae was included as a control in all trials due to its commercial availability and use in the artificial diet used to rear T. leucotreta. Secondly, larval development and attraction assays were conducted with the isolated yeast species. Thaumatotibia leucotreta larvae that fed on Navel oranges inoculated with M. guilliermondii, P. kluyveri, H. uvarum, and S. cerevisiae had accelerated developmental periods and reduced mortality rates. Additionally, it was demonstrated that T. leucotreta neonates were attracted to YPD broth cultures inoculated with P. kluyveri, H. uvarum, P. kudriavzevii and K. marxianus for feeding. Thirdly, oviposition preference assays were conducted with adult T. leucotreta females to determine whether the isolated yeast species influence their egg-laying in two-choice and multiple-choice tests. Navel oranges were inoculated with a specific yeast isolate, and mated adult females were left to oviposit. Meyerozyma guilliermondii, P. kudriavzevii and H. uvarum were shown to influence adult T. leucotreta female oviposition preference in two-choice tests. However, multiple-choice tests using the aforementioned yeast species did not mimic these results. Lastly, a series of detached fruit bioassays were performed to determine the optimal yeast:virus ratio, test all isolated yeast species in combination with CrleGV-SA and to further enhance yeast/virus formulation through the addition of an adjuvant and surfactant. CrleGV-SA was applied at a lethal concentration that would kill 50 % of T. leucotreta larvae. The optimal yeast concentration to use alongside CrleGV-SA was determined. Pichia kluyveri, P. kudriavzevii, K. marxianus and S. cerevisiae in combination with CrleGV-SA increased larval mortality compared to CrleGV-SA alone. The inclusion of molasses and BREAK-THRU® S 240 to P. kudriavzevii and S. cerevisiae plus CrleGV-SA formulations greatly enhanced their efficacy. Additionally, semi-field trials were initiated using P. kudriavzevii and S. cerevisiae, with promising preliminary results being obtained, although more replicates need to be performed. The experiments performed in this study provide a platform for further research into the application of a yeast/virus combination as a novel control and monitoring option for T. leucotreta in the field. , Thesis (PhD) -- Faculty of Science, Biochemistry and Microbiology, 2021
- Full Text:
- Date Issued: 2021-10-29
Assessing South African Medical Interns’ Experience and Confidence in Managing Obstetric Emergencies
- Authors: Miller, Andrew
- Date: 2021-02
- Subjects: Obstetrical emergencies
- Language: English
- Type: Masters theses , text
- Identifier: http://hdl.handle.net/11260/6882 , vital:52352
- Description: Background: Medical doctors in South Africa are required to complete a two-year internship at training hospitals, including a four-month rotation in obstetrics and gynaecology. Following this, doctors are allocated to community service posts; many of which are at district and primary level facilities where supervision is limited. The latest triennial Saving Mothers Report identified district hospitals as the second leading site for maternal deaths of all causes. District hospital were also the leading site for maternal deaths secondary to obstetric haemorrhage and the most likely site for the lack of a skilled doctor to be identified as a factor in deaths associated with caesarean delivery. Methods: This cross-sectional descriptive study aimed to describe the self-perceived readiness of medical interns completing their training to independently manage obstetric emergencies, based on the ESMOE modules in the HPCSA internship logbook. The research assessed medical interns in the last three months of their training, using a self-administered online questionnaire, with data collection between October and December 2019. Cluster sampling of interns at training facilities throughout the country resulted in a total of 182 respondents from 17 hospitals in seven provinces in the country, with an overall response rate of 34.1%. Results: Most interns had experience with, and confidence in, the management of miscarriage and hypertension in pregnancy. However, gaps in labour ward management, pregnancy related sepsis and surgical skills were identified. Only 42.3% of respondents were confident in their ability to diagnose obstructed labour, 26.3% had performed an assisted delivery, 39.0% were confident in their knowledge of the indications and contraindications of assisted deliveries and 35.7% had been involved in the delivery of a baby with shoulder dystocia. Regarding pregnancy related sepsis, 54.4% had experience with managing a wound abscess and 29.7% were confident managing puerperal endometritis. While 78.0% felt confident to perform a caesarean section, only 28.6% had performed uterine compression sutures for uterine atony at caesarean section. Additionally, there was a statistically significant variation in scores between training hospitals. Conclusion: A gap exists between the shortcomings in district hospital obstetric services, the prioritisation of placement of community service doctors at primary care and district hospitals, and the self-perceived readiness of medical interns completing their training to safely manage obstetric emergencies. This highlights the importance of clinical support for junior doctors at district hospitals and standardisation of intern training at accredited facilities across the country. , Thesis (Masters) -- Faculty of Health Sciences, 2021
- Full Text:
- Date Issued: 2021-02
Assessing South African Medical Interns’ Experience and Confidence in Managing Obstetric Emergencies
- Authors: Miller, Andrew
- Date: 2021-02
- Subjects: Obstetrical emergencies
- Language: English
- Type: Masters theses , text
- Identifier: http://hdl.handle.net/11260/6882 , vital:52352
- Description: Background: Medical doctors in South Africa are required to complete a two-year internship at training hospitals, including a four-month rotation in obstetrics and gynaecology. Following this, doctors are allocated to community service posts; many of which are at district and primary level facilities where supervision is limited. The latest triennial Saving Mothers Report identified district hospitals as the second leading site for maternal deaths of all causes. District hospital were also the leading site for maternal deaths secondary to obstetric haemorrhage and the most likely site for the lack of a skilled doctor to be identified as a factor in deaths associated with caesarean delivery. Methods: This cross-sectional descriptive study aimed to describe the self-perceived readiness of medical interns completing their training to independently manage obstetric emergencies, based on the ESMOE modules in the HPCSA internship logbook. The research assessed medical interns in the last three months of their training, using a self-administered online questionnaire, with data collection between October and December 2019. Cluster sampling of interns at training facilities throughout the country resulted in a total of 182 respondents from 17 hospitals in seven provinces in the country, with an overall response rate of 34.1%. Results: Most interns had experience with, and confidence in, the management of miscarriage and hypertension in pregnancy. However, gaps in labour ward management, pregnancy related sepsis and surgical skills were identified. Only 42.3% of respondents were confident in their ability to diagnose obstructed labour, 26.3% had performed an assisted delivery, 39.0% were confident in their knowledge of the indications and contraindications of assisted deliveries and 35.7% had been involved in the delivery of a baby with shoulder dystocia. Regarding pregnancy related sepsis, 54.4% had experience with managing a wound abscess and 29.7% were confident managing puerperal endometritis. While 78.0% felt confident to perform a caesarean section, only 28.6% had performed uterine compression sutures for uterine atony at caesarean section. Additionally, there was a statistically significant variation in scores between training hospitals. Conclusion: A gap exists between the shortcomings in district hospital obstetric services, the prioritisation of placement of community service doctors at primary care and district hospitals, and the self-perceived readiness of medical interns completing their training to safely manage obstetric emergencies. This highlights the importance of clinical support for junior doctors at district hospitals and standardisation of intern training at accredited facilities across the country. , Thesis (Masters) -- Faculty of Health Sciences, 2021
- Full Text:
- Date Issued: 2021-02
Bio-utilization of keratinous waste biomass for the production of keratinolytic proteases by Chryseobactreium aquifrigidense isolated from poultry waste dumpsite
- Authors: Bokveld, Amahle
- Date: 2021-02
- Subjects: Keratin
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/20550 , vital:46120
- Description: Keratin is an insoluble and a fibrous protein that is mostly found in feathers, animal wool, and hair, making them mechanically stable. Avian feathers are the most ubiquitously generated keratinous waste biomass from the poultry processing plants. Keratinous waste biomass valorization could produce amino acids and bioactive peptides. Hence, the bio-recycling of keratin-rich wastes bears an advantage over the chemical and thermal means. In recent times, the microbial keratinases continues to gain traction due to the litany of their potential significance in green technology. Consequently, this study assessed chicken feather degrading and keratinase production potentials of bacteria isolated from a local poultry dumpsite. Soil samples were collected from the poultry dumpsite. Bacteria were isolated using basal salt medium and screened for keratinolytic activity. The identification of potent chicken feather degrading bacterial isolates was through 16S rRNA gene sequence analysis. Keratinase production efficiency of isolates on chicken feather constituted medium was optimized. Hydrolysate's amino acid compositions were quantified, and the keratinases produced was characterized. Out of 22 bacteria isolated from the soil samples, 12 showed a varying degree of proteolytic activity on skimmed milk agar. Four (4) isolates, coded as FPS-01, FPS-07, FPS-09, WDS-06, out of the 12 proteolytic strains further displayed remarkable degradation of the intact chicken feather; percentage degradation ranged from 69 percent for FPS-01 to 88 percent for FPS-09. The extracellular keratinase activity ranged from 610.91 ± 56.57 U/mL for WDS-06 and 834.55 ± 66.86 U/mL for FPS-07. Additionally, the sulfhydryl group concentration quantified from the fermentation broth was 2.22 ± 0.37 (mM), 0.22 ± 0.08 (mM), 2.27 ± 0.09 (mM), and 2.76 ± 0.79 (mM) for FPS-01, FPS-07, FPS-09 and WDS-06, respectively. Based on 16S rRNA gene sequencing and phylogenetic analyses, the isolates FPS-07 and FPS-09 were identified as Chryseobacterium aquifrigidense FANN1 and Chryseobacterium aquifrigidense FANN2. Following the optimization process, the improved fermentation conditions were pH 6, inoculum side (4 percent, v/v), temperature (30 oC), and chicken feather (0.5-1.5 percent, w/v) for FANN1. FANN2 optimal fermentation conditions were pH 6, inoculum (5 percent, v/v), temperature (30 oC), and chicken feather (1.5 percent, w/v). Both bacterial isolates showed the highest extracellular keratinase production after 72 h of the fermentation time. Analysis of the hydrolysates generated from the bacteria fermentation showed a high concentration of arginine, serine, glutamic acid, glycine, proline, valine, and leucine at a respective concentration of 1.13, 1.02, 0.83, 0.94, 0.85, 0.84, and 0.86 (g/100g sample) against FANN1. Similarly, FANN2 generated hydrolysate showed high concentrations of glutamic acid, arginine, serine, aspartic acid, and glycine at this respective abundance 2.52, 1.92, 2.12, 2.25 and 1.9 (g/100g sample). Keratinases from FANN1 and FANN2 showed optimal catalytic efficiency at pH 8 and temperature between 40-50 oC. The enzyme was considerably thermostable at 40 oC and 50 oC after 120 min of preheating. Both FANN1 and FANN2 showed variable residual activity in the presence of the different metal ions. Keratinase from FANN1 recorded the following residual activity of Fe3+ (120 ± 5.06 percent), Ca2+ (100 ± 10.33 percent), Na+ (122 ± 2.95 percent), Al3+ (106 ± 10.33 percent). Likewise, FANN2 keratinase showed remarkable stability against Na+ (108 ± 13.71 percent), Ba2+ (102 ± 0.86 percent), Al3+ (105 ± 2.57 percent), and Ca2+ (96 ± 2.99 percent). Keratinase from FANN1 was catalytically activated after 60 min of pre-treatment with the following detergents, Sunlight (129 percent), Ariel (116 percent), MAQ (151 percent), and Surf (143 percent) compared to the control. FANN2 keratinase showed less stability with laundry detergents after 60 min of preincubation. FANN1 keratinase showed remarkable stability in the presence of chemical agents tested, with residual activity of 90 ± 0.18 percent, 105 ± 7.55 percent, 108 ± 4.31 percent, 123 ± 1.44 percent, 132 ± 1.26 percent, 96 ± 7.19 percent, and 101 ± 3.06 percent for DTT, hydrogen peroxide, DMSO, acetonitrile, triton X-100, tween-80, and SDS, respectively. The enzyme activity was also considerably inhibited by PMSF and EDTA, which suggested a mixed type of protease. Furthermore, keratinase from FANN2 was inhibited by EDTA, and such inhibition pattern grouped it as a metallo-type of protease. The enzyme was also stable in the presence of other chemical agents tested. Therefore, the findings suggest the isolates and their enzymes' relevance to sustainable recycling of recalcitrant keratinous wastes into high-value products with immense application potentials. The remarkable stability shown by keratinases from FANN1 and FANN2, post detergent and chemical agents pre-treatment, indicates promise for the biotechnology and industrial sector. , Thesis(MSc) (Microbiology) -- University of Fort Hare, 2021
- Full Text:
- Date Issued: 2021-02
- Authors: Bokveld, Amahle
- Date: 2021-02
- Subjects: Keratin
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/20550 , vital:46120
- Description: Keratin is an insoluble and a fibrous protein that is mostly found in feathers, animal wool, and hair, making them mechanically stable. Avian feathers are the most ubiquitously generated keratinous waste biomass from the poultry processing plants. Keratinous waste biomass valorization could produce amino acids and bioactive peptides. Hence, the bio-recycling of keratin-rich wastes bears an advantage over the chemical and thermal means. In recent times, the microbial keratinases continues to gain traction due to the litany of their potential significance in green technology. Consequently, this study assessed chicken feather degrading and keratinase production potentials of bacteria isolated from a local poultry dumpsite. Soil samples were collected from the poultry dumpsite. Bacteria were isolated using basal salt medium and screened for keratinolytic activity. The identification of potent chicken feather degrading bacterial isolates was through 16S rRNA gene sequence analysis. Keratinase production efficiency of isolates on chicken feather constituted medium was optimized. Hydrolysate's amino acid compositions were quantified, and the keratinases produced was characterized. Out of 22 bacteria isolated from the soil samples, 12 showed a varying degree of proteolytic activity on skimmed milk agar. Four (4) isolates, coded as FPS-01, FPS-07, FPS-09, WDS-06, out of the 12 proteolytic strains further displayed remarkable degradation of the intact chicken feather; percentage degradation ranged from 69 percent for FPS-01 to 88 percent for FPS-09. The extracellular keratinase activity ranged from 610.91 ± 56.57 U/mL for WDS-06 and 834.55 ± 66.86 U/mL for FPS-07. Additionally, the sulfhydryl group concentration quantified from the fermentation broth was 2.22 ± 0.37 (mM), 0.22 ± 0.08 (mM), 2.27 ± 0.09 (mM), and 2.76 ± 0.79 (mM) for FPS-01, FPS-07, FPS-09 and WDS-06, respectively. Based on 16S rRNA gene sequencing and phylogenetic analyses, the isolates FPS-07 and FPS-09 were identified as Chryseobacterium aquifrigidense FANN1 and Chryseobacterium aquifrigidense FANN2. Following the optimization process, the improved fermentation conditions were pH 6, inoculum side (4 percent, v/v), temperature (30 oC), and chicken feather (0.5-1.5 percent, w/v) for FANN1. FANN2 optimal fermentation conditions were pH 6, inoculum (5 percent, v/v), temperature (30 oC), and chicken feather (1.5 percent, w/v). Both bacterial isolates showed the highest extracellular keratinase production after 72 h of the fermentation time. Analysis of the hydrolysates generated from the bacteria fermentation showed a high concentration of arginine, serine, glutamic acid, glycine, proline, valine, and leucine at a respective concentration of 1.13, 1.02, 0.83, 0.94, 0.85, 0.84, and 0.86 (g/100g sample) against FANN1. Similarly, FANN2 generated hydrolysate showed high concentrations of glutamic acid, arginine, serine, aspartic acid, and glycine at this respective abundance 2.52, 1.92, 2.12, 2.25 and 1.9 (g/100g sample). Keratinases from FANN1 and FANN2 showed optimal catalytic efficiency at pH 8 and temperature between 40-50 oC. The enzyme was considerably thermostable at 40 oC and 50 oC after 120 min of preheating. Both FANN1 and FANN2 showed variable residual activity in the presence of the different metal ions. Keratinase from FANN1 recorded the following residual activity of Fe3+ (120 ± 5.06 percent), Ca2+ (100 ± 10.33 percent), Na+ (122 ± 2.95 percent), Al3+ (106 ± 10.33 percent). Likewise, FANN2 keratinase showed remarkable stability against Na+ (108 ± 13.71 percent), Ba2+ (102 ± 0.86 percent), Al3+ (105 ± 2.57 percent), and Ca2+ (96 ± 2.99 percent). Keratinase from FANN1 was catalytically activated after 60 min of pre-treatment with the following detergents, Sunlight (129 percent), Ariel (116 percent), MAQ (151 percent), and Surf (143 percent) compared to the control. FANN2 keratinase showed less stability with laundry detergents after 60 min of preincubation. FANN1 keratinase showed remarkable stability in the presence of chemical agents tested, with residual activity of 90 ± 0.18 percent, 105 ± 7.55 percent, 108 ± 4.31 percent, 123 ± 1.44 percent, 132 ± 1.26 percent, 96 ± 7.19 percent, and 101 ± 3.06 percent for DTT, hydrogen peroxide, DMSO, acetonitrile, triton X-100, tween-80, and SDS, respectively. The enzyme activity was also considerably inhibited by PMSF and EDTA, which suggested a mixed type of protease. Furthermore, keratinase from FANN2 was inhibited by EDTA, and such inhibition pattern grouped it as a metallo-type of protease. The enzyme was also stable in the presence of other chemical agents tested. Therefore, the findings suggest the isolates and their enzymes' relevance to sustainable recycling of recalcitrant keratinous wastes into high-value products with immense application potentials. The remarkable stability shown by keratinases from FANN1 and FANN2, post detergent and chemical agents pre-treatment, indicates promise for the biotechnology and industrial sector. , Thesis(MSc) (Microbiology) -- University of Fort Hare, 2021
- Full Text:
- Date Issued: 2021-02
Bioconversion of chicken feather into amino acids and keratinase production by mesophilic Chryseobacterium proteolyticum and Pseudomonas aeruginosa isolated from municipal waste dumpsites
- Giwu, Nonkonzo https://orcid.org/0000-0001-9416-7896
- Authors: Giwu, Nonkonzo https://orcid.org/0000-0001-9416-7896
- Date: 2021-02
- Subjects: Poultry -- Processing , Proteolytic enzymes
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/22732 , vital:52720
- Description: Chicken feathers are by-products of poultry processing which are generated in large amount because of the global growing demand for poultry meats. They have high contents of crude proteins in the form of keratin which could be valorized into digestible products. Keratinases are classified as a specific collection of proteolytic enzymes that have the ability for the degradation of recalcitrant keratinous substrates. Isolation and characterization of these enzymes from various microbial producers are gaining prominence in recent years due to their industrial and biotechnological application potentials. For this research, the collection of soil samples was done as well as the isolation of bacteria and the screening for keratinolytic activity. 16S rDNA sequencing and phylogenetic analysis were used to identify the isolates with efficient chicken feathers degrading capacity. Optimum conditions for the fermentation prcocess was enhanced for the production of keratinase. The fermentation broth was also analysed for various amino acids of protein, and the biochemical properties of the enzymes were likewise determined. Twenty two (22) bacteria were isolated from the soil samples, and 18 out of the 22 isolates showed proteolytic activity on solid media with diameters of halo zone that ranged from 5 ± 0.71 mm for isolate coded as PSS-03 to 25 ± 1.41 mm for isolate coded as PSS-06. Intact chicken feathers were degraded by proteolytic bacterial isolates in variable degree that ranged from 24percent for PSS-10 and 81percent for DSS-02. Extracellular keratinase production recorded for the isolates ranged from 63.63 ± 4.14 U/mL for PSS-10 to 693.63 ± 62.99 U/mL for DSS-02. Based on 16S rDNA sequence and phylogenetic analysis, the 2 isolates with remarkable keratinolytic activity coded as DSS-02 and PSS-14 were identified as Chryseobacterium proteolyticum FGNn and Pseudomonas aeruginosa GNFx. C. proteolyticum showed the maximum keratinase production of 756.36 U/mL after 72 h of incubation at optimized fermentation conditions which involved initial medium pH (4), incubation temperature (30 oC), inoculum size (2percent; v/v), and chicken feathers (1.5percent; w/v). Similarly, P. aeruginosa optimally produced keratinase (1055.45 U/mL) after 96 h of incubation at optimized fermentation conditions that involved initial medium pH (7-8), incubation temperature (30 oC), inoculum size (5percent; v/v), and chicken feathers (2.5percent; w/v). Furthermore, feather hydrolysate from C. proteolyticum FGNn had relatively higher abundance (>1.5g/100g sample) of arginine (1.85), serine (1.63), glycine (1.9) and lysine (1.62); while P. aeruginosa GNFx feather hydrolysate showed high abundance of arginine, serine, aspartic acid, glutamic acid, glycine, alanine, valine, and leucine with respective concentration of 2.06, 1.67, 2.39, 3.05, 1.87, 1.73, 1.56 and 1.65 (g/100g sample). The results showed that keratinases from the two bacterial isolates were optimally active at pH 8, and temperature of 50 oC for FGNn keratinase and 50-60 oC for GNFx keratinase. The enzymes displayed remarkable pH stability. Keratinase from C. proteolyticum was catalytically inhibited by EDTA and 1,10-phenanthroline but not affected by PMSF; while P. aeruginosa keratinase was not significantly affected by those class of protease inhibitors. Adiitionally, FGNn keratinase demonstrated high residual activity of 90percent, 103percent, 101percent, 110percent, 130, and 105percent in the presence of DTT, hydrogen peroxides, acetonitrile, triton X-100, tween-80 and SDS, respectively. Similarly, catalytic efficiency of GNFx keratinase was promoted in the presence of hydrogen peroxides (119percent), triton X-100 (140percent), tween-80 (150percent) and SDS (147percent) compared to the control. Furthermore, the keratinases from the both bacterial isolates exhibited catalytic efficiency enhancement and remarkable structural stability in the presence of laundry detergents tested. The findings from the study suggest the application potentials of the isolates for the bioconversion of recalcitrant keratinous wastes into digestible and quality protein hydrolysates. The properties of these microbial keratinases indicate that they may be exploited for various biotechnological and industrial processes especially in the formulation of detergents. , Thesis (MSc) -- Faculty of Science and Agriculture, 2021
- Full Text:
- Date Issued: 2021-02
- Authors: Giwu, Nonkonzo https://orcid.org/0000-0001-9416-7896
- Date: 2021-02
- Subjects: Poultry -- Processing , Proteolytic enzymes
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/22732 , vital:52720
- Description: Chicken feathers are by-products of poultry processing which are generated in large amount because of the global growing demand for poultry meats. They have high contents of crude proteins in the form of keratin which could be valorized into digestible products. Keratinases are classified as a specific collection of proteolytic enzymes that have the ability for the degradation of recalcitrant keratinous substrates. Isolation and characterization of these enzymes from various microbial producers are gaining prominence in recent years due to their industrial and biotechnological application potentials. For this research, the collection of soil samples was done as well as the isolation of bacteria and the screening for keratinolytic activity. 16S rDNA sequencing and phylogenetic analysis were used to identify the isolates with efficient chicken feathers degrading capacity. Optimum conditions for the fermentation prcocess was enhanced for the production of keratinase. The fermentation broth was also analysed for various amino acids of protein, and the biochemical properties of the enzymes were likewise determined. Twenty two (22) bacteria were isolated from the soil samples, and 18 out of the 22 isolates showed proteolytic activity on solid media with diameters of halo zone that ranged from 5 ± 0.71 mm for isolate coded as PSS-03 to 25 ± 1.41 mm for isolate coded as PSS-06. Intact chicken feathers were degraded by proteolytic bacterial isolates in variable degree that ranged from 24percent for PSS-10 and 81percent for DSS-02. Extracellular keratinase production recorded for the isolates ranged from 63.63 ± 4.14 U/mL for PSS-10 to 693.63 ± 62.99 U/mL for DSS-02. Based on 16S rDNA sequence and phylogenetic analysis, the 2 isolates with remarkable keratinolytic activity coded as DSS-02 and PSS-14 were identified as Chryseobacterium proteolyticum FGNn and Pseudomonas aeruginosa GNFx. C. proteolyticum showed the maximum keratinase production of 756.36 U/mL after 72 h of incubation at optimized fermentation conditions which involved initial medium pH (4), incubation temperature (30 oC), inoculum size (2percent; v/v), and chicken feathers (1.5percent; w/v). Similarly, P. aeruginosa optimally produced keratinase (1055.45 U/mL) after 96 h of incubation at optimized fermentation conditions that involved initial medium pH (7-8), incubation temperature (30 oC), inoculum size (5percent; v/v), and chicken feathers (2.5percent; w/v). Furthermore, feather hydrolysate from C. proteolyticum FGNn had relatively higher abundance (>1.5g/100g sample) of arginine (1.85), serine (1.63), glycine (1.9) and lysine (1.62); while P. aeruginosa GNFx feather hydrolysate showed high abundance of arginine, serine, aspartic acid, glutamic acid, glycine, alanine, valine, and leucine with respective concentration of 2.06, 1.67, 2.39, 3.05, 1.87, 1.73, 1.56 and 1.65 (g/100g sample). The results showed that keratinases from the two bacterial isolates were optimally active at pH 8, and temperature of 50 oC for FGNn keratinase and 50-60 oC for GNFx keratinase. The enzymes displayed remarkable pH stability. Keratinase from C. proteolyticum was catalytically inhibited by EDTA and 1,10-phenanthroline but not affected by PMSF; while P. aeruginosa keratinase was not significantly affected by those class of protease inhibitors. Adiitionally, FGNn keratinase demonstrated high residual activity of 90percent, 103percent, 101percent, 110percent, 130, and 105percent in the presence of DTT, hydrogen peroxides, acetonitrile, triton X-100, tween-80 and SDS, respectively. Similarly, catalytic efficiency of GNFx keratinase was promoted in the presence of hydrogen peroxides (119percent), triton X-100 (140percent), tween-80 (150percent) and SDS (147percent) compared to the control. Furthermore, the keratinases from the both bacterial isolates exhibited catalytic efficiency enhancement and remarkable structural stability in the presence of laundry detergents tested. The findings from the study suggest the application potentials of the isolates for the bioconversion of recalcitrant keratinous wastes into digestible and quality protein hydrolysates. The properties of these microbial keratinases indicate that they may be exploited for various biotechnological and industrial processes especially in the formulation of detergents. , Thesis (MSc) -- Faculty of Science and Agriculture, 2021
- Full Text:
- Date Issued: 2021-02
Chicken feather delipidation by lipolytic bacteria isolated from an aquatic environment
- Shiri, Tariro https://orcid.org/0000-0002-0290-9854
- Authors: Shiri, Tariro https://orcid.org/0000-0002-0290-9854
- Date: 2021-02
- Subjects: Keratin
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/21479 , vital:48693
- Description: Keratinous biomass contributes a significant proportion of agro-based wastes in the ecosystem with minimal potentials for valuable product recovery. The generation of huge quantities of chicken feather from poultry processing farms prompts the valorization attempt via diverse avenues. Chicken feathers are a rich source of valuable keratin, yet the overall value chain is rudimentary based on unsustainable recovery techniques involving corrosive chemicals and high energy input processes. Although attempts have been made to extract keratin using microbial techniques successfully, the pre-treatment stage remains dominated by chemical use. Chicken feathers are composed of approximately 91percent keratin, 1percent lipids, and 8percent water. Therefore, lipid removal is a critical step in the valorization process as they contribute to access hindrance of the keratinases and other sulfitolytic systems to keratin. Consequently, the study undertook to explore the environment for lipolytic bacteria capable of degrading chicken feathers' lipid components. Sediment samples were collected for bacteria isolation. The bacteria were evaluated for lipolytic activity, and the potent isolates were identified based on 16S rRNA gene sequencing. The fermentation conditions for the production of extracellular lipases were optimized, and the produced lipases were characterized. Lastly, chicken feather lipids were hydrolysed with lipolytic bacteria. Out of twenty bacteria isolated from the sediment samples, six isolates coded as ACT003, ACT004, ACT010, ACT013, ACT016, and ACT019 showed lipolytic activity on solid media with a respective diameter of 12 mm, 66 mm, 29 mm, 11 mm, 12 mm, and 10 mm. Based on 16S rRNA gene sequencing and phylogenetic analysis, the isolates coded as ACT004 and ACT010 were identified as Bacillus sp. TTs1 and Bacillus sp. TTs2; and the nucleotide sequences were submitted to GenBank (NCBI) with the accession numbers MW556206 and MW556207, respectively. Bacillus sp. TTs1 showed the maximum lipase production of 641.25 U/mL at 72 h, under optimized conditions that included initial pH (5), inoculum size (2percent, v/v), incubation temperature (45 oC), agitation speed (140 rpm), CaCl2 (0.01percent, w/v), yeast extract (1percent, w/v), and tween-80 (10percent, v/v). Similarly, the lipase production by Bacillus sp. TTs2 peaked at 96 h with enzyme activity of 618.8 U/mL in improved fermentation conditions consisting of initial pH (5), inoculum size (2-8percent, v/v), incubation temperature (25 oC), agitation speed (180 rpm), CaCl2 (0.01percent, w/v), yeast extract and peptone (1percent, w/v), and tween-80 (10percent, v/v). The evaluation of chicken feather concentrations on free fatty acid liberation showed that 6-8percent (w/v) chicken feather was adequate with free fatty acids contents of 0.58percent and 0.86percent for Bacillus sp. TTs1 and Bacillus sp. TTs2, respectively. Both isolates' lipases showed remarkable catalytic efficiency at pH and temperature of 7 and 40oC, respectively. The comparative analysis of residual lipids between pre-and post-fermentation indicated a 39.9 ± 7.8percent and 51.2 ± 20.2percent hydrolysis efficiency for Bacillus sp. TTs1 and Bacillus sp. TTs2, respectively. This study's findings indicated the lipolytic potentials of Bacillus spp. and suggest the possibility of a full bio-based approach for chicken feather lipid removal in the valorization of chicken feathers. , Thesis (MSc) -- Faculty of Science and Agriculture, 2021
- Full Text:
- Date Issued: 2021-02
- Authors: Shiri, Tariro https://orcid.org/0000-0002-0290-9854
- Date: 2021-02
- Subjects: Keratin
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/21479 , vital:48693
- Description: Keratinous biomass contributes a significant proportion of agro-based wastes in the ecosystem with minimal potentials for valuable product recovery. The generation of huge quantities of chicken feather from poultry processing farms prompts the valorization attempt via diverse avenues. Chicken feathers are a rich source of valuable keratin, yet the overall value chain is rudimentary based on unsustainable recovery techniques involving corrosive chemicals and high energy input processes. Although attempts have been made to extract keratin using microbial techniques successfully, the pre-treatment stage remains dominated by chemical use. Chicken feathers are composed of approximately 91percent keratin, 1percent lipids, and 8percent water. Therefore, lipid removal is a critical step in the valorization process as they contribute to access hindrance of the keratinases and other sulfitolytic systems to keratin. Consequently, the study undertook to explore the environment for lipolytic bacteria capable of degrading chicken feathers' lipid components. Sediment samples were collected for bacteria isolation. The bacteria were evaluated for lipolytic activity, and the potent isolates were identified based on 16S rRNA gene sequencing. The fermentation conditions for the production of extracellular lipases were optimized, and the produced lipases were characterized. Lastly, chicken feather lipids were hydrolysed with lipolytic bacteria. Out of twenty bacteria isolated from the sediment samples, six isolates coded as ACT003, ACT004, ACT010, ACT013, ACT016, and ACT019 showed lipolytic activity on solid media with a respective diameter of 12 mm, 66 mm, 29 mm, 11 mm, 12 mm, and 10 mm. Based on 16S rRNA gene sequencing and phylogenetic analysis, the isolates coded as ACT004 and ACT010 were identified as Bacillus sp. TTs1 and Bacillus sp. TTs2; and the nucleotide sequences were submitted to GenBank (NCBI) with the accession numbers MW556206 and MW556207, respectively. Bacillus sp. TTs1 showed the maximum lipase production of 641.25 U/mL at 72 h, under optimized conditions that included initial pH (5), inoculum size (2percent, v/v), incubation temperature (45 oC), agitation speed (140 rpm), CaCl2 (0.01percent, w/v), yeast extract (1percent, w/v), and tween-80 (10percent, v/v). Similarly, the lipase production by Bacillus sp. TTs2 peaked at 96 h with enzyme activity of 618.8 U/mL in improved fermentation conditions consisting of initial pH (5), inoculum size (2-8percent, v/v), incubation temperature (25 oC), agitation speed (180 rpm), CaCl2 (0.01percent, w/v), yeast extract and peptone (1percent, w/v), and tween-80 (10percent, v/v). The evaluation of chicken feather concentrations on free fatty acid liberation showed that 6-8percent (w/v) chicken feather was adequate with free fatty acids contents of 0.58percent and 0.86percent for Bacillus sp. TTs1 and Bacillus sp. TTs2, respectively. Both isolates' lipases showed remarkable catalytic efficiency at pH and temperature of 7 and 40oC, respectively. The comparative analysis of residual lipids between pre-and post-fermentation indicated a 39.9 ± 7.8percent and 51.2 ± 20.2percent hydrolysis efficiency for Bacillus sp. TTs1 and Bacillus sp. TTs2, respectively. This study's findings indicated the lipolytic potentials of Bacillus spp. and suggest the possibility of a full bio-based approach for chicken feather lipid removal in the valorization of chicken feathers. , Thesis (MSc) -- Faculty of Science and Agriculture, 2021
- Full Text:
- Date Issued: 2021-02
Democratic citizenship in mathematics teachers’ preparation in South African Universities
- Olawale, Babawande Emmanuel https://orcid.org/ 0000-0001-5265-1583
- Authors: Olawale, Babawande Emmanuel https://orcid.org/ 0000-0001-5265-1583
- Date: 2021-02
- Subjects: Citizenship -- Study and teaching , Authoritarianism , Mathematics -- Study and teaching
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/20079 , vital:45107
- Description: Promoting a clearer understanding of the role of schools in developing democratic dispositions among young citizens is a matter of importance across the world. This is because school is believed to be the best place where future free and democratic citizens can be prepared. Similarly, it is a place where young people are equipped with the necessary skills and knowledge that will assist them in deliberating democratically, developing a better understanding of political structures and economic and world history, and learning the relevant numeracy, literacy and critical thinking skills. Unfortunately, current teacher education programmes appear to represent potential stumbling blocks to schooling playing a greater role in educating the youth for democracy and democratic citizenship. This study explored two contradictory theoretical roles for mathematics teacher education programmes, in relation to power and control in education and society. The first is that, in reality, mathematics teacher education is essentially re-productive, in that its authoritarian relationship does not encourage confrontational discussion or critique, or challenge existing and dominant practices. The second is that, in a world where democracy is increasingly becoming a global phenomenon central to development, teacher education is (or should be) essentially democratic in nature. Thus, underpinned by the interpretivist paradigm, this study employed a qualitative research approach. It also utilised a case study design as a strategy for data collection, in order to explore how the mathematics teacher education programmes in South African universities prepare learners for democratic citizenship. As such, three universities in two provinces in South Africa participated in the study, and data were collected through interviews, observation and document reviews. At each institution, interviews were carried out with mathematics teacher educators and pre-service mathematics student teachers in their second to fourth year of study. Similarly, observations took place in different teaching sessions at each institution, and in different formats. Relevant documents were also reviewed for the study. The research findings revealed that the concepts of democracy and democratic citizenship are multifaceted. The participants’ understanding of these concepts was influenced by their individual expectations, as well as their social, political and economic environments, among many other factors. In addition, it was evident that mathematics teacher education programmes play a significant role in developing socially active citizens and democratic mathematics teachers. The research findings revealed, however, that contradictions exist between pedagogical approaches that are capable of developing democratic citizens, mathematics teacher educators’ ideal image of their practices within the classroom, and the participants’ conception of mathematics. As a result, no engagement occurs in social and critical pedagogy within mathematics education classrooms, to allow learners to view mathematics as a tool for confronting issues of justice and inequality in their community and the world at large. The research findings also revealed that the practices of the main structures which are tasked with the responsibility of promoting democratic practices within higher education institutions seem ineffective, as a result of favouritism and an autocratic approach to decision making. Based on the research findings, a recommendation is made that mathematics educators democratise their classrooms, in order to develop democratic citizens who are committed to democratic principles. Another recommendation is that, in their mathematics classrooms, educators use a problem-posing pedagogical approach which is capable of challenging power structures, thereby empowering learners as users of mathematics. This will not be possible without a professional development programme guiding mathematics teacher educators in establishing and managing their democratic classrooms. Similarly, it is recommended that student representative councils, as the structures that are best known for supporting democratic citizenship at universities, strive to follow the basic principles of democratic governance. Finally, the researcher concluded that mathematics education and the task of preparing mathematics student teachers for democratic citizenship are of the utmost importance, if South Africans are to cultivate and maintain a democracy that contributes to a culture which fundamentally supports democratic principles. , Thesis (PhD) -- Faculty of Education, 2021
- Full Text:
- Date Issued: 2021-02
- Authors: Olawale, Babawande Emmanuel https://orcid.org/ 0000-0001-5265-1583
- Date: 2021-02
- Subjects: Citizenship -- Study and teaching , Authoritarianism , Mathematics -- Study and teaching
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/20079 , vital:45107
- Description: Promoting a clearer understanding of the role of schools in developing democratic dispositions among young citizens is a matter of importance across the world. This is because school is believed to be the best place where future free and democratic citizens can be prepared. Similarly, it is a place where young people are equipped with the necessary skills and knowledge that will assist them in deliberating democratically, developing a better understanding of political structures and economic and world history, and learning the relevant numeracy, literacy and critical thinking skills. Unfortunately, current teacher education programmes appear to represent potential stumbling blocks to schooling playing a greater role in educating the youth for democracy and democratic citizenship. This study explored two contradictory theoretical roles for mathematics teacher education programmes, in relation to power and control in education and society. The first is that, in reality, mathematics teacher education is essentially re-productive, in that its authoritarian relationship does not encourage confrontational discussion or critique, or challenge existing and dominant practices. The second is that, in a world where democracy is increasingly becoming a global phenomenon central to development, teacher education is (or should be) essentially democratic in nature. Thus, underpinned by the interpretivist paradigm, this study employed a qualitative research approach. It also utilised a case study design as a strategy for data collection, in order to explore how the mathematics teacher education programmes in South African universities prepare learners for democratic citizenship. As such, three universities in two provinces in South Africa participated in the study, and data were collected through interviews, observation and document reviews. At each institution, interviews were carried out with mathematics teacher educators and pre-service mathematics student teachers in their second to fourth year of study. Similarly, observations took place in different teaching sessions at each institution, and in different formats. Relevant documents were also reviewed for the study. The research findings revealed that the concepts of democracy and democratic citizenship are multifaceted. The participants’ understanding of these concepts was influenced by their individual expectations, as well as their social, political and economic environments, among many other factors. In addition, it was evident that mathematics teacher education programmes play a significant role in developing socially active citizens and democratic mathematics teachers. The research findings revealed, however, that contradictions exist between pedagogical approaches that are capable of developing democratic citizens, mathematics teacher educators’ ideal image of their practices within the classroom, and the participants’ conception of mathematics. As a result, no engagement occurs in social and critical pedagogy within mathematics education classrooms, to allow learners to view mathematics as a tool for confronting issues of justice and inequality in their community and the world at large. The research findings also revealed that the practices of the main structures which are tasked with the responsibility of promoting democratic practices within higher education institutions seem ineffective, as a result of favouritism and an autocratic approach to decision making. Based on the research findings, a recommendation is made that mathematics educators democratise their classrooms, in order to develop democratic citizens who are committed to democratic principles. Another recommendation is that, in their mathematics classrooms, educators use a problem-posing pedagogical approach which is capable of challenging power structures, thereby empowering learners as users of mathematics. This will not be possible without a professional development programme guiding mathematics teacher educators in establishing and managing their democratic classrooms. Similarly, it is recommended that student representative councils, as the structures that are best known for supporting democratic citizenship at universities, strive to follow the basic principles of democratic governance. Finally, the researcher concluded that mathematics education and the task of preparing mathematics student teachers for democratic citizenship are of the utmost importance, if South Africans are to cultivate and maintain a democracy that contributes to a culture which fundamentally supports democratic principles. , Thesis (PhD) -- Faculty of Education, 2021
- Full Text:
- Date Issued: 2021-02
Development and assessment of rifampicin loaded self-microemulsifying drug delivery systems
- Authors: Mphaphuli, Mashudu Theodore
- Date: 2021-04
- Subjects: To be added
- Language: English
- Type: thesis , text , Masters , MSc
- Identifier: http://hdl.handle.net/10962/178503 , vital:42945
- Description: Access restricted until April 2023. , Thesis (MSc) -- Faculty of Pharmacy, Pharmacy, 2021
- Full Text:
- Date Issued: 2021-04
- Authors: Mphaphuli, Mashudu Theodore
- Date: 2021-04
- Subjects: To be added
- Language: English
- Type: thesis , text , Masters , MSc
- Identifier: http://hdl.handle.net/10962/178503 , vital:42945
- Description: Access restricted until April 2023. , Thesis (MSc) -- Faculty of Pharmacy, Pharmacy, 2021
- Full Text:
- Date Issued: 2021-04
Development and characterisation of ciprofloxacin hydrochloride solid lipid nanoparticles for ocular delivery
- Authors: Dhege, Clarence
- Date: 2021-04
- Subjects: To be added
- Language: English
- Type: thesis , text , Masters , MSc
- Identifier: http://hdl.handle.net/10962/178446 , vital:42940
- Description: Access restricted until April 2023. , Thesis (MSc) -- Faculty of Pharmacy, Pharmacy, 2021
- Full Text:
- Date Issued: 2021-04
- Authors: Dhege, Clarence
- Date: 2021-04
- Subjects: To be added
- Language: English
- Type: thesis , text , Masters , MSc
- Identifier: http://hdl.handle.net/10962/178446 , vital:42940
- Description: Access restricted until April 2023. , Thesis (MSc) -- Faculty of Pharmacy, Pharmacy, 2021
- Full Text:
- Date Issued: 2021-04
Electrochemical sensing based on functionalised carbon dots prepared by bottom-up approach
- Madikizela, Ziyanda https://orcid.org/0000-0003-0405-8464
- Authors: Madikizela, Ziyanda https://orcid.org/0000-0003-0405-8464
- Date: 2021-02
- Subjects: Electrochemical analysis , Electrodes, Carbon
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/22545 , vital:52424
- Description: This research was aimed at preparing carbon dots using the microwave method as a bottomup synthetic approach. The prepared carbon dots were them to be used as an electrode modifier in electrochemical detection of metal ion. The structure of the carbon dots prepared were characterized using different techniques including the FTIR, TEM, UV-Vis, PL, XRD and Raman Spectroscopy. It was observed that the nanoparticles consisted of carboxylic acid, amine and alcohol functional groups at their core and surface. UV-Vis and PL revealed that the carbon dots absorb more light in the visible and ultraviolet region, and the sizes of the carbon dots prepared were less than 10 nm. The carbon dots were then utilized for electrochemical sensing of Cd2+ ion, which is considered as one of harmful heavy metal ion when not controlled. Glassy carbon electrode modified with the carbon dots was utilized for the detection of Cd2+ through square wave voltammetry. Effect of different experimental parameters was studied which include electrode preparation, frequency, and amplitude. The electrochemical characterization of the electrode was done using the cyclic voltammetry and electrochemical impedance spectroscopy (EIS), the modified electrode was found conductive with much improved electrochemical performances. The obtained detection limit for Cd2+ sensing was 9.39 ppb, the developed C-dots modified GCE electrode was also tested with tap water Cd2+ spiked solution to demonstrate its implementation in real sample analysis. , Thesis (MA) -- Faculty of Science and Agriculture, 2021
- Full Text:
- Date Issued: 2021-02
- Authors: Madikizela, Ziyanda https://orcid.org/0000-0003-0405-8464
- Date: 2021-02
- Subjects: Electrochemical analysis , Electrodes, Carbon
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/22545 , vital:52424
- Description: This research was aimed at preparing carbon dots using the microwave method as a bottomup synthetic approach. The prepared carbon dots were them to be used as an electrode modifier in electrochemical detection of metal ion. The structure of the carbon dots prepared were characterized using different techniques including the FTIR, TEM, UV-Vis, PL, XRD and Raman Spectroscopy. It was observed that the nanoparticles consisted of carboxylic acid, amine and alcohol functional groups at their core and surface. UV-Vis and PL revealed that the carbon dots absorb more light in the visible and ultraviolet region, and the sizes of the carbon dots prepared were less than 10 nm. The carbon dots were then utilized for electrochemical sensing of Cd2+ ion, which is considered as one of harmful heavy metal ion when not controlled. Glassy carbon electrode modified with the carbon dots was utilized for the detection of Cd2+ through square wave voltammetry. Effect of different experimental parameters was studied which include electrode preparation, frequency, and amplitude. The electrochemical characterization of the electrode was done using the cyclic voltammetry and electrochemical impedance spectroscopy (EIS), the modified electrode was found conductive with much improved electrochemical performances. The obtained detection limit for Cd2+ sensing was 9.39 ppb, the developed C-dots modified GCE electrode was also tested with tap water Cd2+ spiked solution to demonstrate its implementation in real sample analysis. , Thesis (MA) -- Faculty of Science and Agriculture, 2021
- Full Text:
- Date Issued: 2021-02
Enhancing the psychological strength of adolescent rugby players in South African secondary schools : The effects of Rational-Emotive Behavioural Therapy and Mindfulness-Acceptance-Commitment Therapy
- Munnik, James Barry https://orcid.org/0000-0001-8211-4260
- Authors: Munnik, James Barry https://orcid.org/0000-0001-8211-4260
- Date: 2021-02
- Subjects: Rational emotive behavior therapy , Acceptance and commitment therapy , Psychotherapy
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/22111 , vital:51984
- Description: This thesis aimed, firstly, to test the psychological effects of two psychological interventions designed to enhance the psychological strength of competitive athletes; and, secondly, to possibly determine which intervention might be considered superior to the other. The third aim of this thesis was to explore the results of the findings in terms of both their shared and differential theories. The two psychological approaches in question were Rational-Emotive Behavioural Therapy (REBT) – supplemented with adjunctive Mental Skills Training (MST) techniques and the Mindfulness-Acceptance-Commitment (MAC) approach. To test the psychological strengthening effects of both interventions and to compare the results, a non-equivalent pre-test post-test control group design was followed which utilised a control group along with purposive sampling. Various dependent variables were investigated using seven instruments. Variables tested included: - mental wellbeing, irrational beliefs, mental toughness, achievement motivation and competitive anxiety, as well as anger and frustration levels and subjective performance. The instruments used to capture these variables were: - The Mental Health Continuum-Short Form (MHC-SF); Shortened General Attitudes and Beliefs Scale (SGABS); the Sport Mental Toughness Questionnaire (SMTQ); the Sport Competition Anxiety Test (SCAT); as well as one five-point Likert question written by the researcher and one question from the Psychological Skills Inventory (PSI). Seventy-one male adolescent rugby players, from three different schools were sourced to take part in this study. Thus 32 (Mage = 17.33; SD = 6= .729) participants from one high school completed the seven-session REBT-Based MST intervention. 21 (Mage = 17.23; SD = .669) from another school completed the seven-module MAC intervention and 18 (Mage = 15.52; SD = .326) from an additional school were used as a control group school. All three group participants filled out the instrument questionnaires prior to undergoing the various interventions and just following it. Each intervention’s sessions were about an hour to an hour and fifteen minutes long. The control group just filled out the instrument questionnaires in about the same time frame that the other schools had their pre- and post-intervention assessments. The results demonstrated that generally both interventions improved the psychological strength of their players more so than the control group, however, the REBT intervention decreased irrationality and improved subjective performance measures more significantly when compared to the other treatment group. , Thesis (PhD) -- Faculty of Social Sciences and Humanities, 2021
- Full Text:
- Date Issued: 2021-02
- Authors: Munnik, James Barry https://orcid.org/0000-0001-8211-4260
- Date: 2021-02
- Subjects: Rational emotive behavior therapy , Acceptance and commitment therapy , Psychotherapy
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/22111 , vital:51984
- Description: This thesis aimed, firstly, to test the psychological effects of two psychological interventions designed to enhance the psychological strength of competitive athletes; and, secondly, to possibly determine which intervention might be considered superior to the other. The third aim of this thesis was to explore the results of the findings in terms of both their shared and differential theories. The two psychological approaches in question were Rational-Emotive Behavioural Therapy (REBT) – supplemented with adjunctive Mental Skills Training (MST) techniques and the Mindfulness-Acceptance-Commitment (MAC) approach. To test the psychological strengthening effects of both interventions and to compare the results, a non-equivalent pre-test post-test control group design was followed which utilised a control group along with purposive sampling. Various dependent variables were investigated using seven instruments. Variables tested included: - mental wellbeing, irrational beliefs, mental toughness, achievement motivation and competitive anxiety, as well as anger and frustration levels and subjective performance. The instruments used to capture these variables were: - The Mental Health Continuum-Short Form (MHC-SF); Shortened General Attitudes and Beliefs Scale (SGABS); the Sport Mental Toughness Questionnaire (SMTQ); the Sport Competition Anxiety Test (SCAT); as well as one five-point Likert question written by the researcher and one question from the Psychological Skills Inventory (PSI). Seventy-one male adolescent rugby players, from three different schools were sourced to take part in this study. Thus 32 (Mage = 17.33; SD = 6= .729) participants from one high school completed the seven-session REBT-Based MST intervention. 21 (Mage = 17.23; SD = .669) from another school completed the seven-module MAC intervention and 18 (Mage = 15.52; SD = .326) from an additional school were used as a control group school. All three group participants filled out the instrument questionnaires prior to undergoing the various interventions and just following it. Each intervention’s sessions were about an hour to an hour and fifteen minutes long. The control group just filled out the instrument questionnaires in about the same time frame that the other schools had their pre- and post-intervention assessments. The results demonstrated that generally both interventions improved the psychological strength of their players more so than the control group, however, the REBT intervention decreased irrationality and improved subjective performance measures more significantly when compared to the other treatment group. , Thesis (PhD) -- Faculty of Social Sciences and Humanities, 2021
- Full Text:
- Date Issued: 2021-02
Ethnobotany and conservation biology of Warburgia salutaris (G.Bertol.) Chiov., a threatened medicinal plant in southern Mozambique
- Authors: Senkoro, Annae Maria
- Date: 2022-04-08
- Subjects: Ethnobotany Mozambique , Conservation biology Mozambique , Canellaceae Habitat Mozambique , Canellaceae Genetics , Warburgia salutaris Habitat Mozambique , Warburgia salutaris Genetics , Endangered plants Mozambique , Biogeography Climatic factors Mozambique , Traditional medicine Mozambique , Traditional ecological knowledge Mozambique
- Language: English
- Type: Doctoral thesis , text
- Identifier: http://hdl.handle.net/10962/232967 , vital:50042 , DOI 10.21504/10962/232967
- Description: Warburgia salutaris, locally known as “chibaha” (Ronga, Tsonga), “isiBhaha” (Zulu) and “siBhaha” (Siswati), is one of the most highly-valued medicinal plant species in southern Africa. Its bark has long been employed to treat bacterial and fungal infections, and it is often a front line herbal treatment for malaria. The species is popular in rural and urban areas due to its lower price compared to commercial pharmaceuticals and because of its long-standing spiritual and symbolic significance. Consequently, W. salutaris is threatened in Malawi, South Africa and Swaziland and is believed to be extincted in the wild in Zimbabwe. In Mozambique, where the tree is confined to the southern part of the country, it is considered vulnerable due to high local demand and cross-border export. Although there is limited research, further work is urgently needed to provide the basis for options and strategies to achieve desired outcomes. This study aimed to explore different approaches for the conservation of W. salutaris in the Lebombo Mountains (LM), the Tembe River (TR) and the Futi Corridor (FC) areas, in southern Mozambique. For this, potential distribution, socio cultural factors that influenced sustainable management of the species, demography, harvest impact, genetic diversity and population differentiation were considered. The kuenm package in R, 2 846 occurrence and 11 environmental data were used to model the potential current and future distribution in 2050 and 2070 using four general circulation models (CESM1(BGC), ACCESS1.3, FIO-ESM and IPSL-CM5A-MR) under representative concentration pathways (RCPs) 4.5 and 8.5. The extent of occurrence (EOO) and habitat suitability (HS) were also determined. Stratified random semi-structured interviews with 182 heads of households were carried out to explore cultural and socio incentives of use, compared knowledge distribution, determine local management practices and explore local ecological knowledge related to the species in the three study areas. In addition, 17 focus group discussion were conducted to clarify issues raised during household interviews. One hundred and twenty four quadrants were used to determine the abundance and population structure. The Simpson index of dominance, permutation index and quotient between consecutive classes were used to assess population stability, and an eight point scale was used to evaluate the extent of bark damages. Genomic deoxyribonucleic acid (gDNA) (n=48) was used to assessed genetic diversity and population structure through the newly developed single sequence repeats (SSR) molecular markers. Model selected was statistical significant for prediction of potential distribution of W. salutaris in southern Mozambique (partial ROC =0.00, omission rate = 0.04 and delta AICc = 0.00). The current environmental conditions mostly explained by climatic predictor, indicated in general, the potential distribution on areas of occurrence observed during the field work in southern Mozambique. Future project suggested an increase of climatic suitable areas in all the general circulation models in both conservative and pessimistic climatic scenarios (RCPs 4.5 and 8.5, respectively) in 2050 and 2070, and consequently the increase of HS and the EOO. Results of this work suggests W. salutaris would not extinct at least in the coming 50 years due to climate change but other threats such as overexploitation of the species need to be addressed. With increase of climatic suitable areas, conservation and management of this species could focus on reintroduction and cultivation for recovery of the species, with the help of time. W. salutaris was used for medicinal purposes to treat 12 health problems, with the bark being the most commonly used part (92% of informants). Knowledge of the species uses differed significantly between the three study areas but not with respondent gender or age. Informants also mentioned a considerable number of alternative species of W. salutaris (37 species in LM, 33 species in TR and 17 species in FC). Local ecological knowledge on the ecological niche of the species also varied substantial in the three areas with both types of knowledge generally higher in the Tembe River area. Local management practises were revealed mostly on harvesting through vertical bark stripping cited by 100% of informants in TR, 61.6% FC and 51.7 LM (71% of all informants). Yet most (64.3% of all informants, corresponding to 98.4% in TR, 51.7% in Fc and 41.7% LM) used non-traditional harvesting tools (machete) bark removal. For sustainable use of the species, consideration should be given to combined conservation strategies such as the use of alternative species with the same application, substitution of bark by leaves, and increases in alternative sources of plant material through cultivation. The densities of alive stems were not statistically different in the three areas but was higher in LM (mean of 4500.3±9209.8 stems/ha). Equally the mean densities of recruits (diameter ≤2 cm) were not considerable different but was higher in the FC (3296.8±9116.7 stems/ha). The regression analyses for the three study area revealed negative slopes, indicating more recruits and fewer individuals in larger classes. The Simpson indexes of dominance, permutation indexes and quotients between the consecutive size classes suggested some levels of population instability in the three areas. Harvesting took place in the eight point scale, all size classes were harvested but preference was higher on intermediate (15.1-20 cm) or larger (>20 cm) size classes in all the study areas but gatherers avoided harvesting bark from recruits. Although the mean densities of harvested stem was not significant this work indicated higher levels of stem destruction in FC. Harvested dead stems ware significant in the three areas and FC had the higher of (39.5±85.9 stems/ha) compared to 7.6±19.1 and 2.1±4.3 in TR and LM, respectively. Equally, the density of physiologically stressed stems differed substantially in the three areas with higher in FC 20.5± 75.5 stems/ha compared to 18.7±82.9 stems/ha in TR and 3.8±11.8 stems/ha in LM. This results suggests implementation of protection measures such as the inclusion of the species in the national CITES list to regulated cross-border trade and strengthening of the law enforcement. Genetic diversity, structure and gene flow in the exiting populations of southern Mozambique revealed that despite fragmentation and overexploitation, this species maintains a relatively high level of genetic diversity supporting the existence of random mating. Two genetic groups were found corresponding to the northern (LM and TR) and southern (FC) areas. The study suggests that, if local extinctions occurred in Mozambique, the pepper-bark tree persisted in sufficient numbers to retain a large proportion of genetic diversity. Management plans should concentrate on maintaining this high level of genetic variability through both in and ex-situ conservation actions. , Thesis (PhD) -- Faculty of Science, Environmental Science, 2022
- Full Text:
- Date Issued: 2022-04-08
- Authors: Senkoro, Annae Maria
- Date: 2022-04-08
- Subjects: Ethnobotany Mozambique , Conservation biology Mozambique , Canellaceae Habitat Mozambique , Canellaceae Genetics , Warburgia salutaris Habitat Mozambique , Warburgia salutaris Genetics , Endangered plants Mozambique , Biogeography Climatic factors Mozambique , Traditional medicine Mozambique , Traditional ecological knowledge Mozambique
- Language: English
- Type: Doctoral thesis , text
- Identifier: http://hdl.handle.net/10962/232967 , vital:50042 , DOI 10.21504/10962/232967
- Description: Warburgia salutaris, locally known as “chibaha” (Ronga, Tsonga), “isiBhaha” (Zulu) and “siBhaha” (Siswati), is one of the most highly-valued medicinal plant species in southern Africa. Its bark has long been employed to treat bacterial and fungal infections, and it is often a front line herbal treatment for malaria. The species is popular in rural and urban areas due to its lower price compared to commercial pharmaceuticals and because of its long-standing spiritual and symbolic significance. Consequently, W. salutaris is threatened in Malawi, South Africa and Swaziland and is believed to be extincted in the wild in Zimbabwe. In Mozambique, where the tree is confined to the southern part of the country, it is considered vulnerable due to high local demand and cross-border export. Although there is limited research, further work is urgently needed to provide the basis for options and strategies to achieve desired outcomes. This study aimed to explore different approaches for the conservation of W. salutaris in the Lebombo Mountains (LM), the Tembe River (TR) and the Futi Corridor (FC) areas, in southern Mozambique. For this, potential distribution, socio cultural factors that influenced sustainable management of the species, demography, harvest impact, genetic diversity and population differentiation were considered. The kuenm package in R, 2 846 occurrence and 11 environmental data were used to model the potential current and future distribution in 2050 and 2070 using four general circulation models (CESM1(BGC), ACCESS1.3, FIO-ESM and IPSL-CM5A-MR) under representative concentration pathways (RCPs) 4.5 and 8.5. The extent of occurrence (EOO) and habitat suitability (HS) were also determined. Stratified random semi-structured interviews with 182 heads of households were carried out to explore cultural and socio incentives of use, compared knowledge distribution, determine local management practices and explore local ecological knowledge related to the species in the three study areas. In addition, 17 focus group discussion were conducted to clarify issues raised during household interviews. One hundred and twenty four quadrants were used to determine the abundance and population structure. The Simpson index of dominance, permutation index and quotient between consecutive classes were used to assess population stability, and an eight point scale was used to evaluate the extent of bark damages. Genomic deoxyribonucleic acid (gDNA) (n=48) was used to assessed genetic diversity and population structure through the newly developed single sequence repeats (SSR) molecular markers. Model selected was statistical significant for prediction of potential distribution of W. salutaris in southern Mozambique (partial ROC =0.00, omission rate = 0.04 and delta AICc = 0.00). The current environmental conditions mostly explained by climatic predictor, indicated in general, the potential distribution on areas of occurrence observed during the field work in southern Mozambique. Future project suggested an increase of climatic suitable areas in all the general circulation models in both conservative and pessimistic climatic scenarios (RCPs 4.5 and 8.5, respectively) in 2050 and 2070, and consequently the increase of HS and the EOO. Results of this work suggests W. salutaris would not extinct at least in the coming 50 years due to climate change but other threats such as overexploitation of the species need to be addressed. With increase of climatic suitable areas, conservation and management of this species could focus on reintroduction and cultivation for recovery of the species, with the help of time. W. salutaris was used for medicinal purposes to treat 12 health problems, with the bark being the most commonly used part (92% of informants). Knowledge of the species uses differed significantly between the three study areas but not with respondent gender or age. Informants also mentioned a considerable number of alternative species of W. salutaris (37 species in LM, 33 species in TR and 17 species in FC). Local ecological knowledge on the ecological niche of the species also varied substantial in the three areas with both types of knowledge generally higher in the Tembe River area. Local management practises were revealed mostly on harvesting through vertical bark stripping cited by 100% of informants in TR, 61.6% FC and 51.7 LM (71% of all informants). Yet most (64.3% of all informants, corresponding to 98.4% in TR, 51.7% in Fc and 41.7% LM) used non-traditional harvesting tools (machete) bark removal. For sustainable use of the species, consideration should be given to combined conservation strategies such as the use of alternative species with the same application, substitution of bark by leaves, and increases in alternative sources of plant material through cultivation. The densities of alive stems were not statistically different in the three areas but was higher in LM (mean of 4500.3±9209.8 stems/ha). Equally the mean densities of recruits (diameter ≤2 cm) were not considerable different but was higher in the FC (3296.8±9116.7 stems/ha). The regression analyses for the three study area revealed negative slopes, indicating more recruits and fewer individuals in larger classes. The Simpson indexes of dominance, permutation indexes and quotients between the consecutive size classes suggested some levels of population instability in the three areas. Harvesting took place in the eight point scale, all size classes were harvested but preference was higher on intermediate (15.1-20 cm) or larger (>20 cm) size classes in all the study areas but gatherers avoided harvesting bark from recruits. Although the mean densities of harvested stem was not significant this work indicated higher levels of stem destruction in FC. Harvested dead stems ware significant in the three areas and FC had the higher of (39.5±85.9 stems/ha) compared to 7.6±19.1 and 2.1±4.3 in TR and LM, respectively. Equally, the density of physiologically stressed stems differed substantially in the three areas with higher in FC 20.5± 75.5 stems/ha compared to 18.7±82.9 stems/ha in TR and 3.8±11.8 stems/ha in LM. This results suggests implementation of protection measures such as the inclusion of the species in the national CITES list to regulated cross-border trade and strengthening of the law enforcement. Genetic diversity, structure and gene flow in the exiting populations of southern Mozambique revealed that despite fragmentation and overexploitation, this species maintains a relatively high level of genetic diversity supporting the existence of random mating. Two genetic groups were found corresponding to the northern (LM and TR) and southern (FC) areas. The study suggests that, if local extinctions occurred in Mozambique, the pepper-bark tree persisted in sufficient numbers to retain a large proportion of genetic diversity. Management plans should concentrate on maintaining this high level of genetic variability through both in and ex-situ conservation actions. , Thesis (PhD) -- Faculty of Science, Environmental Science, 2022
- Full Text:
- Date Issued: 2022-04-08