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Maize seed variety identification model using image processing and deep learning

  • Authors: Gebeyehu, Seffi , Shibeshi, Zelalem S
  • Date: 2024
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/429191 , vital:72566 , DOI: 10.11591/ijeecs.v33.i2.pp990-9985
  • Description: Maize is Ethiopia’s dominant cereal crop regarding area coverage and production level. There are different varieties of maize in Ethiopia. Maize varieties are classified based on morphological features such as shape and size. Due to the nature of maize seed and its rotation variant, studies are still needed to identify Ethiopian maize seed varieties. With expert eyes, identification of maize seed varieties is difficult due to their similar morphological features and visual similarities. We proposed a hybrid feature-based maize variety identification model to solve this problem. For training and testing the model, images of each maize variety were collected from the adet agriculture and research center (AARC), Ethiopia. A multi-class support vector machine (MCSVM) classifier was employed on a hybrid of handcrafted (ie, gabor and histogram of oriented gradients) and convolutional neural network (CNN)-based feature selection techniques and achieved an overall classification accuracy of 99%.
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  • Date Issued: 2024

Systematic effects and mitigation strategies in observations of cosmic re-ionisation with the Hydrogen Epoch of Reionization Array

  • Authors: Charles, Ntsikelelo
  • Date: 2024
  • Subjects: Uncatalogued
  • Language: English
  • Type: Academic theses , Doctoral theses , text
  • Identifier: http://hdl.handle.net/10962/432605 , vital:72886 , DOI 10.21504/10962/432605
  • Description: The 21 cm transition from neutral Hydrogen promises to be the best observational probe of the Epoch of Reionisation (EoR). It has driven the construction of the new generation of lowfrequency radio interferometric arrays, including the Hydrogen Epoch of Reionization Array (HERA). The main difficulty in measuring the 21 cm signal is the presence of bright foregrounds that require very accurate interferometric calibration. However, the non-smooth instrumental response of the antenna as a result of mutual coupling complicates the calibration process by introducing non-smooth calibration errors. Additionally, incomplete sky models are typically used in calibration due to the limited depth and resolution of current source catalogues. Combined with the instrumental response, the use of incomplete sky models during calibration can result in non-smooth calibration errors. These, overall, impart spectral structure on smooth foregrounds, leading to foreground power leakage into the EoR window. In this thesis we explored the use of fringe rate filters (Parsons et al., 2016) as a mean to mitigate calibration errors resulting from the effects of mutual coupling and the use of an incomplete sky model during calibration. We found that the use of a simple notch filter mitigates calibration errors reducing the foreground power leakage into the EoR window by a factor of ∼ 102. Thyagarajan et al. (2018) proposed the use of closure phase quantities as a means to detect the 21 cm signal, which has the advantage of being independent (to first order) from calibration errors and, therefore, bypasses the need for accurate calibration. In this thesis, we explore the impact of primary beam patterns affected by mutual coupling on the closure phase. We found that primary beams affected by mutual coupling lead to a leakage of foreground power into the EoR window, which can be up to ∼ 104 times and is mainly caused by the unsmooth spectral structure primary of primary beam sidelobes affected by mutual coupling. This power leakage was confined to k < 0.3 pseudo h Mpc−1. Lastly, we also proposed and demonstrated an analysis technique that can be used to derive a flux scale correction in post-calibrated HERA data. We found that after applying flux scale correction to calibrated HERA data, the bandpass error reduces significantly, with an improvement of 6%. The derived flux scale correction was antenna-independent, and it can be applied to fix the overall visibility spectrum scale of H4C data post-calibration in a fashion similar to Jacobs et al. (2013). , Thesis (PhD) -- Faculty of Science, Physics and Electronics, 2024
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  • Date Issued: 2024

The nexus between COVID-19 and sexual and reproductive health of adolescents: Bringing adolescents ‘home’

  • Authors: Kangaude, Godfrey , Macleod, Catriona I
  • Date: 2024
  • Subjects: To be catalogued
  • Language: English
  • Type: text , book chapter
  • Identifier: http://hdl.handle.net/10962/434171 , vital:73036 , ISBN 9781032671420 , https://www.routledge.com/COVID-19-and-the-Right-to-Health-in-Africa/Durojaye-Mahadew/p/book/9781032671420?_ga=1281847179.1711584000
  • Description: The devastating impact of the COVID-19 virus is well-documented. The disease was less severe among young people than in the older population. The effect on adolescents was primarily due to government measures to curb the pandemic, including lockdowns that disrupted social, education, and health services and diverted resources away from sexual and reproductive health. Young people lost or had limited access to sexual and reproductive health services and comprehensive sexuality education. They experienced the loss of financial and emotional support and parental care because of sick adults and caregivers. Young persons also lost time with friends and in developmental tasks associated with adolescence, such as exploring intimate relationships and forming identities outside the home. Government-imposed lockdowns and isolation measures revealed how being home can be problematic for young people, despite the concept of ‘home’ suggesting safety, security, and nurturance. Of particular concern were sexual and gender-based violence in the home and the increase in teenage pregnancies. In this chapter, we engage with the notion of home and how all institutions with which the adolescent interacts, especially family and school, should be a ‘home’: A place of belonging and acceptance because adolescence is a critical time for the emergence of sexual identity.
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  • Date Issued: 2024

Rationalisation of magisterial districts to transform the judiciary and widen access to justice under the RSA constitution of 1996

  • Authors: Skosana, Jacob
  • Date: 2024-01
  • Subjects: Justice, Administration of , Law and socialism , Human rights -- South Africa
  • Language: English
  • Type: Doctoral theses , text
  • Identifier: http://hdl.handle.net/10353/28162 , vital:72777
  • Description: The study examines how pre-1994 magisterial districts jurisdictions denied access to justice to many South Africans, and ongoing efforts to reverse this injustice. Delayed rationalisation of the judiciary and reform of the courts territorial jurisdiction during the apartheid era exacerbated the problem. The courts administered justice along spatial racial divide, and given the location of the courts, many black communities had to commute long distances to access justice and at a great cost and inconvenience. The Constitution of South Africa of 1996 provides not only for the right to equality before the law and equal protection and benefit of the law but also the right to access the courts and seek recourse. In a period spanning eight years from December 2014, new magisterial districts were proclaimed in all the nine provinces of South Africa. Despite this milestone and the imperative of the 1996 Constitution, the rationalisation process is still in its infancy: old legislation and judicial structures remain intact; divisions of the High Court continue to exercise jurisdictions determined for the pre-1994 constitutional dispensation. The status quo continues to perpetuate the denial of access to justice to communities especially those living in areas that hitherto formed part of the former homelands and self-governing ‘states’. The study was conducted through a desktop survey of primary and secondary material relevant to the rationalisation process. It drew lessons from the re-demarcation of municipal boundaries which, like magisterial districts, were based on racial laws and policies of the past. It also contrasted rationalisation principles in comparable jurisdictions. The findings provide a useful contribution to the ongoing effort to effect rationalisation of the court system. They also contribute to knowledge and enriches our understanding of the relationship that underpins the administration of justice in a dispensation driven by democratic, human rights and constitutional ethos. , Thesis (PhD (LLD)) -- Faculty of Law, 2024
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  • Date Issued: 2024-01

A Combined Experimental and Computational Study of Hydridospirophosphorane Ligand Systems Featuring Halogenated Mandelic Acids

  • Authors: Maritz, Marius Johann
  • Date: 2023-12
  • Subjects: Organic compounds -- Synthesis , Heterocyclic compounds , catalysis -- South Africa
  • Language: English
  • Type: Master's theses , text
  • Identifier: http://hdl.handle.net/10948/62096 , vital:71911
  • Description: The search for new stereoselective catalysts remains important for the isolation of enantiomeric products from racemic mixtures. The need exists for these catalysts to be more efficient, to be more cost effective as well as be stable over time without undergoing changes in molecular structure and selectivity. The purpose of this research project was to experimentally synthesise and characterise asymmetric catalysts for the use in enantioselective synthesis. The catalysts consisted of the main group element phosphorous as central atom, with the phenyl rings of mandelic acid ligands monosubstituted with halogen atoms fluorine, chlorine and bromine in different configurations. Ligand binding resulted in the formation of hydridospirophosphorane structures, from which the molecular properties and binding geometry of these molecules could be explained by the theory of apicophilicity. Characterization was performed by NMR and IR spectroscopy as well as diffraction studies that provided the experimental crystal structures. The structural, energetic and spectroscopy results were compared to the theoretically obtained molecular properties using DFT analysis. Various interand intramolecular interactions that existed between molecules found in crystal packing environments were discussed. Additional properties that were investigated included modelling solvation effects, molecular orbital analysis, Hirshfeld surfaces, orbital and atomic energy and population analysis as well as ESP energy calculations with the optimized crystal structures as input. Molecular overlay comparisons were also performed between the experimental and optimized structures where the effectiveness of various DFT functionals and basis sets could be determined. The method with the best overall cost-to-accuracy ratio was found to be the triple-zeta def2-tzvp basis set with B3LYP functional theory and the addition of Grimme’s dispersion correction. Results indicated differences in crystal packing depending largely on the given halogen atoms present in the substituted phenyl rings, with differences observed in electronegativity and steric effects. One of the crystal systems showed additional interactions with solvent molecules, giving the impression that obtaining crystal void formation was possible. Alterations in the transition state activation energies between the isomers of each molecule were found to be present and supported the theory behind the mechanism of stereochemical induction. The studied compounds were therefore effective in isolating different enantiomeric ligands by means of energy differences between conformers and displayed unique catalytic properties resulting from the phosphorous main group element. The hydridospirophosphoranes conformers responsible for the lowest theoretically calculated activation energy induced crystallization as was seen by diffraction results for all compounds. Even as an intriguing observation, crystallization will largely depend on solubility rather than a specific conformer’s amount in solution. , Thesis (MSc) -- Faculty of Science, School of Biomolecular and Chemical Sciences, 2023
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  • Date Issued: 2023-12

A digital transformation framework for municipalities in the Eastern Cape

  • Authors: Luke, Lamla Lonwabo Leadley
  • Date: 2023-12
  • Subjects: Internet in public administration , Information technology -- Political aspects , Electronic government information
  • Language: English
  • Type: Master's thesis , text
  • Identifier: http://hdl.handle.net/10948/62506 , vital:72779
  • Description: Digital transformation (DT) integrates technology into all business areas, fundamentally changing how businesses operate and deliver value to their clients. It is also a cultural change that requires organisations to continually challenge the status quo, experiment and get comfortable with change. Smart Municipalities in South Africa have various challenges concerning integrating services and information flow among departments within the municipalities, thus preventing the creation of value for the citizens. The ongoing digital transformation revolutionises urban development and governance, offering opportunities for enhanced citizen services, resource optimisation, and sustainable growth. However, the complexity of implementing smart city initiatives demands a structured approach. Due to urbanisation, municipal management in developing nations must deal with issues like increased energy consumption, pollution, the disposal of toxic wastes, resource depletion, ineffective management of urban infrastructures, ineffective planning processes, overloaded transportation networks, endemic congestion, as well as social inequality and socioeconomic disparity. The extent of digital adoption in the South African province of the Eastern Cape has provided municipalities with a learning opportunity to change into data-driven Smart Municipalities in order to increase productivity, growth, employment, and the need for people with a variety of skills. This study required a review of the literature to examine digital transformation, Smart Municipalities, Smart Municipalities at national and international levels, and Smart Municipality models. The literature review also helped to create a Smart Municipality conceptual model. Data for this study were collected in four Eastern Cape municipalities, namely: DR. AB. Xuma, Enoch Mgijima, Intsika Yethu Local municipalities, and their critical stakeholder Chris Hani District Municipality. The population was all municipal workers, including Municipal Managers, Councillors, Executive Management, ICT officials, Unit Managers, Computer Users and other municipal employees who were using IT to do their job responsibilities within the municipalities. This research study followed a positivistic approach using quantitative methods of analysis. Accordingly, the conceptual model was hypothesised and tested using a questionnaire to collect data and the data were statistically analysed. The study followed a descriptive research designwith a quantitative approach. Various statistical analyses were conducted, including descriptive statistics, reliability and validity metrics of the research instrument, correlation coefficients and Exploratory Factor Analysis (EFA). South Africa has provided municipalities with a learning opportunity to change into data-driven Smart Municipalities to increase productivity, growth, and employment supported by the need for people with a variety of skills. A Value Alignment Smart City Stakeholder (VASCS) model was created in previous research and identified nine dimensions of a smart city, namely Smart Economy, Smart Environment, Smart Governance, Smart Living, Smart Mobility, Smart Organisation, Smart People, Smart Policies and Smart Technology. Due to lack of DT framework and guidelines that guides municipalities on how they can adopt Smart Municipality concept, the objective of this study was to propose and evaluate a Value Alignment Smart Municipality Stakeholder (VASMS) model for municipalities in the Eastern Cape. The nine dimensions were empirically evaluated by stakeholders in four Eastern Cape municipalities. The results depict a change towards the importance of developing a Smart Municipality in the four municipalities, while following appropriate planning, designing, management, operations and governance guidelines. The respondents regarded the smart policy dimension as the most important dimension in the proposed VASMS model. This study further provided practical guidelines for the adoption of smart municipalities in the Eastern Cape Province of South Africa. This proposed VASMS model aims to address the unique challenges faced by municipalities in the Eastern Cape as they embark on their digital transformation journey. It outlines a stepby- step process encompassing strategic planning, technological integration, stakeholder engagement, and governance restructuring. Moreover, it emphasises the importance of fostering a collaborative ecosystem between government agencies, private sector partners, and citizens. By offering this VASMS model, this research contributes to the advancement of Smart Municipality initiatives in the Eastern Cape, ultimately paving the way for more efficient, resilient, and citizen-centric urban environments. , Thesis (MCom) -- Faculty of Science, School of Computing Sciences, 2023
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  • Date Issued: 2023-12

A feminist critical discourse analysis of male dominance and violence in Zakes Mda’s the Madonna of excelsior and Chimamanda Ngozi Adichie’s purple hibiscus

  • Authors: Ibitoye, Antonia Folasade
  • Date: 2023-12
  • Subjects: Feminism and education , Feminism and literature
  • Language: English
  • Type: Doctoral's theses , text
  • Identifier: http://hdl.handle.net/10948/63320 , vital:73249
  • Description: This study critically explored male dominance and violence in Africa, through the lens of South African author, Zakes Mda, and Nigerian author, Chimamanda Ngozi Adichie, in their novels, The Madonna of Excelsior (2004) and Purple Hibiscus (2003), respectively. Women globally often continue to live with male dominance, and this unequal gender structure has propelled feminists to commence movements to counter all forms of discrimination against women. For the study, excerpts from the two novels were used as data, to investigate male dominance and violence in Africa. To achieve the goals of this research, the study used socialist feminist theory, post-colonial feminist theory, and black feminist theory as the theoretical framework. This combined framework explicates that there is not just one system of oppression at the core of unequal treatment of women by men. Rather, it is a combination of structures related to social class, gender, race, sexuality, culture and society. Feminist critical discourse analysis (FCDA) was employed to analyse the data with the aid of ATLAS.ti software. FCDA was selected as an analytical framework because of its concern for the emancipation of women and social justice with transformation.What prompted the area of concern and the research problem of this study was an awareness of the extensive gender inequality in Nigeria and South Africa, which tends to be rooted in male dominance and violence. As a result, this study contributes to creating awareness of gender inequality, suggesting ways of combating violence against women and female suppression as well as promoting new conceptualisations of masculinity, femininity, and inequality. This research study explored how language use constructed identity, gender, and power relations and how these have reflected male dominance, and violence in Africa in the novels chosen for this study. This study is significant because it did not only analysed the marginalisation and suppression of the female gender but further exposed the strategies that were adopted by women to confront patriarchal oppression and domination as well as the resultant effect on the perpetrators as depicted in the novels for this study. The distinctiveness of this study can be viewed from three different perspectives. Firstly, it is one of the first research works to use FCDA to address the social problems of male dominance and violence. Secondly, it is the first research work which recognises the use of the novel as an essential source of data for FCDA on male dominance and violence. Using the novel as a data source supports the fact that novels are relevant data sources because 5 they often reflect the happenings in society, such as the incidence of gender inequality. Lastly, this project is distinctive because of its ability to combine socialist feminist theory, black feminist theory, post-colonial feminist theory as the theoretical framework and FCDA as the methodological approach. The study is limited to two novels from two African writers because the novels are reflections of the challenges faced by women in Africa and because of the novelists’ unique use of language and the representation of male dominance, violence and female suppression in Africa. The choice to restrict the scope of the study to Africa, selecting Nigeria and South Africa was because, both novels are set in African context and also as a result of the gravity of the identified social and equity issues in Africa. For further research, the study could be extended beyond the African continent to other continents. By so doing, other feminist theories could be used while FCDA could still be used as an analytical framework. Furthermore, a comparative analysis of male dominance and violence between South Africa and Nigeria could also be explored or between Africa and the western world. This study, therefore, explored how language use constructed gender identity and how this reflected male dominance and violence in Africa through the novels, which provided the data for analysis. Following the principles of FCDA, the study sought to create social awareness and to build an understanding of the need not only to resist male dominance and violence but to extend understandings of gender differences with the intention of generating a collective change and transformation in society for gender equality. , Thesis (PhD) -- Faculty of Humanities, 2023
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  • Date Issued: 2023-12

A qualitative review on the manner in which psychologists address language barriers in psychological testing with isiXhosa speaking clients.

  • Authors: Fouche, Nicoleen
  • Date: 2023-12
  • Subjects: language barriers , isiXhosa , psychological tests,
  • Language: English
  • Type: Master's theses , text
  • Identifier: http://hdl.handle.net/10948/62838 , vital:73055
  • Description: A racially segregated culture historically influenced the growth of psychological testing and evaluation in South Africa. Thus, South Africa's multicultural and multilingual community poses difficulties for psychologists in their daily work. Most of the psychological tests used by psychologists are predominantly normed in either or only English/Afrikaans. Given the economic and professional resources required to develop new standardised tests for the broader South African population, the current status quo is set to continue for the foreseeable future. Consequently, language barriers pose a challenge when psychometric standardised tests are administered in a language that is different from that of the client, and as a result, psychologists must develop ways to enhance the fairness of these measures for their client base. The avenue of research that was explored is how psychologists overcome the language boundary when assessing clients who speak an indigenous first language, particularly isiXhosa. As such, this study explored this question through qualitative methods. Through purposive sampling, nine psychologists were invited to share their practical expertise on this topic, using semi-structured online interviews. The findings of this study suggested several core themes providing useful methods for other psychologists facing the same challenge, including the challenges with administering psychological tests with isiXhosa clients, the availability of standardised tests in the South African context, and the importance of determining the client’s language proficiency. Five themes with several sub-themes emerged from the study. The study contributes to the currently limited existing body of knowledge, and subsequently to the research area that this study explores - thus further providing guidelines that practitioners can employ when working with clients who are isiXhosa speaking. , Thesis (Ma) -- Faculty of Health Science, 2023
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  • Date Issued: 2023-12

A study exploring the understanding and interpretations of schizophrenia amongst Zulu Community members, in Durban, Kwa-Zulu Natal Province

  • Authors: Lephoto, Thabo
  • Date: 2023-12
  • Subjects: chizophrenia , traditional healers , cultural belief,
  • Language: English
  • Type: Master's theses , text
  • Identifier: http://hdl.handle.net/10948/62859 , vital:73059
  • Description: Mental illness is a global and widespread phenomenon, and its presented symptoms are experienced differently within various contexts. In many contexts, cultural beliefs are noted as influencing the thinking, feeling, and behavior of individuals and groups. Schizophrenia is often associated with a clustering of symptoms, which are often interpreted from within a cultural lens. This is in part, due to the lack of access to mental health facilities, and the limited understanding of psychological processes, but primarily due to cultural belief systems. As such, many individuals rely on indigenous knowledge systems and traditional healing when experiencing psychological symptoms. Within South Africa, the symptoms associated with schizophrenia are understood and treated in accordance with cultural beliefs and it is likely that bewitchment, spirit possession, as well as ancestral callings such as ukuthwasa, etc. will be associated with the symptoms of mental illnesses. The implications that this poses to psychological treatments and interventions are vast and require exploration. This study employed a qualitative methodology, with an exploratory and descriptive design. There were 8 participants (males= 4; females= 4), aged between 26-37 that were recruited for the study by utilizing a purposive sampling strategy, as well as a snowball sampling technique. Thematic analysis was used as a means of data analysis, by following the method by Braun and Clarke. The study applies the principles of ethics with regard to confidentiality and privacy. The findings of the study revealed that participants’ perceptions of schizophrenia were influenced by their culture. Participants of the study suggested that culture is influential in the treatment of those diagnosed with schizophrenia. Furthermore, the study revealed that there is a hierarchical system in the Zulu Culture and those diagnosed with schizophrenia are placed at the bottom. , Thesis (Ma) -- Faculty of Health Science, 2023
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  • Date Issued: 2023-12

Adherence narratives of COVID-19 in KwaNobuhle Township, Eastern Cape

  • Authors: Andries, Siyanda
  • Date: 2023-12
  • Subjects: Coronavirus Disease--Eastern Cape--South Africa , Vaccination--Eastern Cape, South Africa
  • Language: English
  • Type: Master's theses , text
  • Identifier: http://hdl.handle.net/10948/63243 , vital:73240
  • Description: The emergence of COVID-19 triggered a global health crisis that not only took many lives but disrupted economies, strained healthcare systems, and impacted social relations globally. KwaNobuhle township in the Eastern Cape province of South Africa falls under the Nelson Mandela Bay Metropolitan Municipality. This municipality experienced some of South Africa’s highest COVID-19 fatalities, with the lowest levels of testing, active cases and hospitalisation in the country. This study investigates the narratives about COVID-19 prevention measures in KwaNobuhle. Primarily, it seeks to reveal how young and elderly peoples’ perceptions about COVID-19 influenced their compliance with prevention measures such as lockdown, testing and self-admission to hospital when sick. Fifteen residents of KwaNobuhle, who identify as Black people between 18 and 30 years and 50 and 65 years, were recruited as participants in this study. The two groups of study participants were recruited in order to enable an investigation into intergenerational narratives about infectious disease. In this study, Intergenerational narratives encompass stories, beliefs, and cultural traditions that transmit values, historical experiences, and a shared sense of identity, fostering connections between generations. This study provides an historical overview of how communities dealt with previous epidemics in South Africa and analyses how COVID-19 disrupted the lives of people with the preventative measures and changes that were implemented by the government. Social constructivism is a theory that emphasizes the role of social interactions and cultural context in shaping individuals' understanding of the world. Social constructivism theory is employed to frame the investigation of narratives of COVID-19 and is based on qualitative data collected through in-depth telephonic individual interviews. The data reveals that participants’ perceptions and narratives of diseases are shaped and influenced by their experiences and knowledge of the same. The findings confirm that the two different age groups of participants have distinct perspectives of COVID-19. Older participants rely on their past experiences of diseases, while younger participants form their understanding through mainstream and social media. This study further examines the inadequacy of healthcare system preparedness in South Africa to adequately address the onset of infectious diseases. Furthermore, this investigation unveils the way preventive measures against COVID-19 imposed inconvenience upon individuals' daily lives and overall lifestyles. These measures included curfews, a limitation on crowd size in public spaces vii such as markets, and the prohibition of alcohol consumption. Individuals who were reliant on the alcohol industry as their primary source of income were adversely affected. African traditional practices were also impacted, as burial custom alterations resulted. Lastly, the study illuminates that the acceptance and uptake of vaccinations was influenced by vaccine hesitancy, with social media serving as a prominent conduit for the proliferation of conspiracy theories in the context of COVID-19. , Thesis (Ma) -- Faculty of Humanities, 2023
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  • Date Issued: 2023-12

An architecture for feedback-driven learning analytics

  • Authors: Winfield, Philip John
  • Date: 2023-12
  • Subjects: Educational statistics -- Data processing , Education -- Research -- Statistical methods , Teacher-student relationships
  • Language: English
  • Type: Master's theses , text
  • Identifier: http://hdl.handle.net/10948/62744 , vital:72935
  • Description: Feedback from students provides an opportunity to gain insights into students’ learning behaviour and participation in higher education learning and teaching. Academic staff are expected to constantly review and improve the learning and teaching environment where feedback contributes vital information toward pedagogical decision-making. Reviewing student feedback is essential but time-consuming, making it crucial to explore more effective and efficient ways to analyse and present feedback that encourages intervention and support. The general design science research evaluation pattern guided the construction and evaluation of a Feedback-Driven Architecture (FDA) for Learning Analytics (LA) to address this problem. An FDA implementation using a suitable case demonstrated each component validating the feasibility and effectiveness of the proposed design. The components identified for inclusion in the FDA were integrated within layers of a three-tiered architecture pattern. The data layer incorporates the collection, preparation and storage of learning management system data which includes free-form narrative student feedback. The application layer contains logic to support the analysis of free-form narrative student feedback and extraction of learning analytics. Arrangement and visualisation of information in the presentation layer aim to promote appropriate intervention and support. Evaluation using a case study showed that the FDA provided necessary guidelines for developing an implementation that produced feedbackdriven learning analytics. Data preparation transformed unstructured data into a suitable representation for effective analysis. Cohorts within narrative feedback responses were identified using the k-means clustering algorithm and latent Dirichlet allocation. Logistic regression and support vector machines were applied as predictive models and trained using extracted quantitative markers to predict academic success. , Thesis (MSc) -- Faculty of Science, School of Computer Science, Mathematics, Physics and Statistics, 2023
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  • Date Issued: 2023-12

An exploration of stakeholder perceptions of the quality of teaching and learning in higher education

  • Authors: Jackson,Linda Grace
  • Date: 2023-12
  • Subjects: Quality assurance --Education (Higher)-- South Africa , Teaching and learning – Nelson Mandela University , Quality education—South Africa
  • Language: English
  • Type: Doctoral theses , text
  • Identifier: http://hdl.handle.net/10948/62464 , vital:72757
  • Description: Quality in higher education is a complex and evolving concept that has been a subject of measurement, assurance and promotion in universities globally for the past three decades. However, its precise definition remains elusive due to its fluid nature, influenced by various contextual factors and stakeholder perspectives. This study explored the concepts of quality teaching and quality learning within the specific context of Nelson Mandela University, focusing on two critical internal stakeholder groups, lecturers and students. By maintaining a constant context, the study sought to gain a deeper understanding of how these stakeholders perceived and contributed to the overall quality of education at the institution. Defining quality in higher education (HE) is important, as it directly impacts on the evaluation processes within educational institutions. Presently, most Higher Education Institutions (HEIs) assess quality using tangible inputs and outputs, resulting in a quantifiable representation of quality. Despite this approach, realistically, the anticipated improvements in the quality of teaching and learning are not apparent, leading to concerns about graduate readiness for the demands of the workforce. This situation raises imperative questions about the quality of teaching and learning within HEIs, necessitating a response to address this issue. This study used the conceptual model Schindler et al. (2015) developed to investigate stakeholder perceptions of quality teaching and quality learning in higher education (HE). The research followed a novel perspective by uncoupling quality in HE from the prevailing neoliberal approach and considering quality in HE within social inclusion interventions (Gidley et al., 2010a) already in place in HE settings. The research methodology expanded on social inclusion theory and employed a qualitative, participative and visual approach adapted from Mmogo-method®, an indigenous method. The research design fostered active participation from the participants, who assumed the role of co-researchers. Participants constructed their answers to the research question using unstructured materials, subsequently sharing, explaining, and interpreting their viewpoints within the group setting. , Thesis (PhD) -- Faculty of Education, School of teaching and learning, 2023
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  • Date Issued: 2023-12

Assessing land degradation and the effectiveness of calcrete bontveld rehabilitation in a grassridge PPC cement mining area using multi-sensor remotely sensed data and machine learning techniques

  • Authors: Mpisane, Khanyisa
  • Date: 2023-12
  • Subjects: Land degradation -- South Africa , Environmental degradation , Mines and mineral resources -- South Africa
  • Language: English
  • Type: Master's theses , text
  • Identifier: http://hdl.handle.net/10948/62527 , vital:72821
  • Description: This study uses multi-temporal remote sensing data to spatially visualise and quantify land degradation due to mining as well as Calcrete Bontveld rehabilitation at the Grassridge PPC Cement mine, Gqeberha formerly known as Port Elizabeth in the Eastern Cape, South Africa. Botanical field data is also used to verify the suasses of rehabilitation in the area. SPOT-6 and Landsat multi-spectral images were compared, and Support Vector Machine and Random Forest algorithms were used for classification in order to determine which yields more accurate results for a limestone mine. Support Vector Machine analysis using SPOT-6 images yielded the best results. This was due to the high spatial resolution of SPOT-6 compared to Landsat and Support Vector Machine classifier was able to classify images with fewer training points compared to Random Forest. The spatio-temporal land cover change at the mine was then determined between the years 2000, 2015 and 2020. Land cover classification is useful for monitoring land degradation and, in this case, was able to show the extent of rehabilitation success. For the year 2020, a 17% area was rehabilitated; however, the algorithm could not distinguish between unmined Calcrete Bontveld matrix and rehabilitation sites that were older than five years. The performed change detection also showed that 29.50% of unmined Calcrete Bontveld matrix had changed to “mature rehabilitation” (rehabilitation sites older than five years). Again, for this percentage in some areas the algorithm could not distinguish between the unmined Calcrete Bontveld matrix and rehabilitation sites that were older than five years due to high similarities between the two land cover types. Area changes of the different land cover classes could also be used to demonstrate how rehabilitation areas have matured over time and lead to the conclusion that most of the Calcrete Bontveld which was mined, has over the years been successfully rehabilitated. Vegetation analysis was conducted to further validate the rehabilitation success of Calcrete Bontveld matrix. Multivariant Detrended Correspondent Analysis showed that rehabilitation sites which were younger than five years (2–year-old rehabilitation plots that were sampled) had great dissimilarity to the natural unmined Calcrete Bontveld matrix and that rehabilitation sites older than five years, in this case 16–years older, had high similarity and resemblance to natural unmined Calcrete Bontveld matrix and therefore could be considered as being mature. This was a more definitive assessment as it considers all aspects of the vegetation. Species cover and species richness also showed that Calcrete Bontveld matrix rehabilitation sites which have been rehabilitated for more than 5 years had greater similarity to natural unmined vegetation compared to areas that have been rehabilitated for less than five years. This study, therefore, demonstrates that due to the high similarity between mature rehabilitation sites and unmined Calcrete Bontveld, rehabilitation has been successful. , Thesis (MSc) -- Faculty of Science, School of Environmental Sciences, 2023
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  • Date Issued: 2023-12

Assessing the effectiveness of smart solutions on potable water in rural areas within Ngqushwa local municipality

  • Authors: Fodo, Portia Noluthando
  • Date: 2023-12
  • Subjects: Potable water -- tap water , water infrastructure
  • Language: English
  • Type: Master's theses , text
  • Identifier: http://hdl.handle.net/10948/63298 , vital:73245
  • Description: Providing potable water is a critical reposition towards achieving the Sustainable Development Goal (SDG) 6, to ensure the availability and sustainable management of water and sanitation for all. In addition, the use of smart solutions facilitates towards guaranteeing smart cities aligned with SDG11 which is aimed at making cities and human settlements inclusive, secure, resilient and viable. Access to potable water is a challenging issue in most rural areas as these areas were affected by the Apartheid regime where services were distributed according to the colour of the skin. In rural areas where many black people reside, the challenge of service delivery still exists. Ngqushwa Municipality is faced with several trials in the management of water, including water scarcity, lack of water infrastructure as well as illegal water connections. Despite more than 25 years of democracy, rural dwellers in Ngqushwa Municipality still suffer from a deficiency of access to potable water, which results in other health problems, such as Cholera. This study was aimed at assessing the role of smart solutions in the effective management of potable water in rural areas in Ngqushwa Local Municipality. The objectives to be achieved include identification of the policies that support the implementation of smart solutions in the provision of potable water in Ngqushwa Local Municipality, as well as determining the opportunities and challenges associated with smart solutions in the delivery of potable water. Moreover, identifying the existing difficulties affecting the execution of smart solutions in the delivery of potable water, along with developing recommendations on how smart solutions can effectively be put into operation in rural areas to control water. A qualitative research approach was applied as the chosen research methodology most appropriate to achieving the objectives of the research study. Data was collected using secondary sources and was analysed using thematic content analysis. The study revealed that opportunities available include accurate billing, smart metering and information availability. Furthermore, the obstacles included capacity constraints, cost factors and resistance to change. The investigation recommended, inter alia, that the municipality should accurately train its employees on matters relating to change management and establish effective debt controlling mechanisms to enhance water supervision in rural areas. , Thesis (MA) -- Faculty of Humanities, 2023
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  • Date Issued: 2023-12

Assessing the effectiveness of the planning, utilisation and implementation of the electronic human resource management strategy: a case of the department of home affairs in the Eastern Cape

  • Authors: Dyan, Margaret Nombuyiselo
  • Date: 2023-12
  • Subjects: Personnel management , Home Affairs -- Eastern Cape
  • Language: English
  • Type: Master's theses , text
  • Identifier: http://hdl.handle.net/10948/63287 , vital:73244
  • Description: This study assessed the effectiveness of planning, implementing and utilising the electronic human resource management (e-HRM) strategy within the King William’s Town (KWT) Department of Home Affairs (DHA) in the Eastern Cape Province (EC) of South Africa (SA). E-HRM emerged because of the advent of technology. Many organisations use information technology to optimise the performance of both the employees and the organisation. Thus, this technology has been incorporated into organisations’ human resource functions, taking advantage of the latest technology to deliver an online real-time human resource management (HRM) solution. Therefore, this study sought to assess the e-HRM strategy's effectiveness within the KWT DHA. The technology acceptance model was adopted as a theoretical framework for the study to explain the adoption of the e-HRM strategy. A qualitative research approach using a case study research design was used for this study. Non-probability purposive sampling and convenience sampling were used to identify participants for the study. These participants provided the information needed to answer the research questions. The data was collected using in-depth interviews with the participants. The data was then analysed using thematic analysis following Braun and Clarke’s guidelines (2006). The study results revealed that implementing the e-HRM strategy within KWT DHA proves to be effective and efficient. The strategy’s implementation has been associated with improved performance of the KWT DHA in the Eastern Cape. It also saves time and ensures that HR information is accessed easily. The study also found barriers to the planning, implementation and utilisation of the e-HRM strategy, including a lack of skills and knowledge and resource constraints. The study also found that the current e-HRM policies are not fully functional. The study recommends continuous personnel training regarding the strategy, maximising the use of the e-HRM strategy and addressing the resource challenges. , Thesis (MA) -- Faculty of Humanities, 2023
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  • Date Issued: 2023-12

Assessing the effects of fish stock management on Cape gannet foraging behaviour in South Africa

  • Authors: Strydom, Zanri , Grémillet, David , Pichegru, Lorien
  • Date: 2023-12
  • Subjects: Gannets -- South Africa , Birds of prey -- Behavior -- South Africa , Fish stock assessment
  • Language: English
  • Type: Doctoral theses , text
  • Identifier: http://hdl.handle.net/10948/62622 , vital:72887
  • Description: Seabirds are one of the most threatened groups of birds under both marine and terrestrial pressures. Among seabirds, the Cape gannet Morus capensis is a southern African endemic species facing several pressures of anthropogenic origin, including competition with industrial fisheries on small pelagic fish stocks. Cape gannets, being a long-lived species that is sensitive to environmental changes, are sentinels of change in oceanic environments granting it important to understand which factors influence their foraging behaviour and breeding outputs. For example, factors like age can result in a loss of physical capabilities which can lead to behavioral compensation and subsequent changes in chick provisioning rates and amounts. With the current fisheries management the fish stocks are continually decreasing, indicating the importance of an updated fine-scale assessment on the spatiotemporal overlap between foraging gannets and fisheries. The first objective of this thesis was to determine the influence of adult Cape gannets’ age and sex on their foraging characteristics and energy expenditure during foraging. I equipped chick-rearing Cape gannets of known age and sex with a 3D accelerometer and GPS device. Foraging effort (trip duration, foraging path and maximum distance to the nest) did not differ between sexes nor with age in Cape gannets. Both sexes rested less on the water with age. Aging females also spent more time in flight than males. The age- and sexual differences in energy expenditure prevalent in our study might reflect niche and/or risk partitioning strategies to ensure adequate provisioning to the chick. The second objective of this thesis was to determine the influence of fisheries catch rates, sardine and anchovy biomass, and adult foraging effort on chick growth rates in Cape gannets, using a long-term dataset collected between 2005 and 2020 on Malgas Island. I equipped chick-rearing adults with a GPS device and I weighed the chicks for between 3 to 6 increments to calculate the average daily mass increment. Of all the variables, foraging trip duration was the main determinant of daily growth rates, with chicks benefitting from parents’ shorter foraging trip durations. Chicks tended to grow slower when fisheries catch of sardine and anchovy were higher, possibly an effect of competition with fisheries. Chicks also grew faster when fish biomass was higher. This long-term monitoring demonstrated the possible effect of food competition between Cape gannets and fisheries, with negative impacts on gannet fitness as determined via chick growth rates. The third objective of this thesis was to determine the influence of both the biomass and fisheries catch rates of sardine and anchovy on Cape gannet foraging effort at a spatial and temporal scale. This was achieved by equipping a total of 668 chick-rearing Cape gannets with a GPS device. With an increase in fisheries catch there was an increase in the birds’ foraging effort. To reduce competition between the gannets and fisheries, the gannets’ core foraging areas seldomly overlapped with the fisheries catch locations, at the cost of the gannets’ increased foraging effort. One method to halt the Cape gannet population decline would be to conserve the fish resources close to the breeding colonies. This would reduce the birds’ foraging whereby increasing their fitness. Safeguarding small pelagic fish to ensure the perseverance of the remaining Benguela seabird populations, would lead to preserving the Benguela marine ecosystem as a whole. My study provided new insight into effects of fish stock management on Cape gannet foraging behaviour in South Africa, and the need for adequate management to ensure population persistence. , Thesis (PhD) -- Faculty of Science, School of Environmental Sciences, 2023
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  • Date Issued: 2023-12

Assessment of knowledge, attitudes, practices and the prevalence of intestinal parasites in Sarah Baartman District, Eastern Cape

  • Authors: Mrwebi, Sisanda
  • Date: 2023-12
  • Subjects: Intestinal parasites , Knowledge Attitudes and Practices , transmitted helminths
  • Language: English
  • Type: Master's theses , text
  • Identifier: http://hdl.handle.net/10948/62924 , vital:73070
  • Description: ntestinal parasites also known as parasitic worms are one of the common water, soil and feacal transmitted infections of public importance in the world. This study evaluated the Knowledge, Attitudes and Practices (KAP) of public workers comprising EPWP and CWP general workers on intestinal parasites in a selected municipality in the study area . Additionally, using secondary data, the researcher established the prevalence of intestinal parasites in Sarah Baartman District Municipality (SBDM) from 2012 to 2020. Method: The study made use of a quantitative, cross-sectional research design resembling a study by S.D. Hambury .A structured questionnaire, closed-ended, telephonically-administered questionnaire was used to collect data from 160 Expanded Public Works Programme (EPWP) and Community Work Programme (CWP) general workers. Data on the prevalence was obtained from the SBDM National Health Laboratory Service (NHLS). Data was analysed using both inferential and descriptive statistics using SPSS software version 16.1, inferential statistics tests used were Chi2 square tests and p-value tests. Descriptive statistic tests used included frequency distributions, percentage, cumulative percent, and valid percent. Results: The participants’ overall awareness, attitudes and practices of the study were poor, 64.4% of the study participants had the correct knowledge about intestinal parasite infections. The age of study participants and who the participants thought was at risk of being infected by intestinal parasites had a non significant relationship (p>0.05). Gender and the responses to who is at risk of getting infected with intestinal parasites had a statistically significant (p<0.05) relationship. Intestinal parasite prevalence from 2012 to 2020 in SBDM was 46.37% which means it was close to half of the sampled population. Males had the highest prevalence as compared to females, with a prevalence of 53.1% xvi in males and 46.9% in females. The highest disease infection was found between ages one and six years. Conclusion: The researcher concluded that the overall awareness, attitudes and practices on intestinal parasites in SBDM were poor. The intestinal parasites present in SBDM were Cytoisospora belli (35.4%) and Giardia lamblia (35.4%), Ascaris lumbricoides (17.7%), Trichuris trichiura (3%), and Taenia species (2%). The study also revealed that the prevalence of intestinal parasites was low from 2012 to 2020. Recommendations were made with an emphasis on education to increase disease prevention and control awareness. , Thesis (Ma) -- Faculty of Health Science, 2023
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  • Date Issued: 2023-12

Case-based research on the fedup model for self-help housing

  • Authors: Qumbisa, Nolwazi
  • Date: 2023-12
  • Subjects: Community participation , Human settlements , Informal settlements
  • Language: English
  • Type: doctoral's theses , text
  • Identifier: http://hdl.handle.net/10948/62199 , vital:72007
  • Description: In South Africa, the government subsidises the building of starter homes to meet the demand for housing for people with lower incomes. However, it is necessary for the state to revise its efforts to meet the demand for housing in the country. Self-help housing is a model that can be used as an alternative to state housing subsidies. The present research study investigates the essential aspects of sustainable self-help housing in the central region of South Africa. The present study aimed to address the central research topic by eliciting responses from participants: How can self-help provision become sustainable in the central region of South Africa? In response to the question, an effective self-help housing support model was developed, the aim of which is to outline how self-help housing projects could be improved. The literature findings demonstrate the potential of this model as a viable alternative to the existing housing delivery mechanism in South Africa. This assertion is supported by a study of self-help housing trajectories and an examination of relevant South African housing policies. However, there has been a lack of emphasis on the simplification of current models to accommodate the needs of implementers, government entities, and beneficiaries of self-help housing initiatives. This study aimed to address the highlighted gaps by utilising a qualitative methodology and drawing upon the data obtained. The data collection techniques included semi-structured interviews, structured observations, and focus-group discussions. A total of 25 semi-structured interviews were conducted with key stakeholders in human settlements, while the focus-group discussions involved 50 participants. A total of 5 focus group discussions were conducted with each group consisting of 10 participants. Moreover, the researcher conducted a document analysis, observations, and questionnaire survey. The data collected were analysed thematically. The results revealed that there are still challenges with implementing self-help housing. Moreover, the results are attributed mainly to a mismatch of the roles and responsibilities and not understanding the Enhanced People’s Housing Process (EPHP) policy. The principal contribution of the thesis is that housing policies, programmes and sector plans must encourage beneficiaries to play an active role. This study found that weak or unclear project vi specifications lead to contractor misunderstandings or discrepancies in housing project implementation, resulting in poor-quality work or delays. The conventional contractor-driven housing-delivery model also has issues like poor construction, corruption and mismanagement, profit-driven contractors, high contractor rates, project delays/incomplete projects, illegal occupation of incomplete projects, riots and disputes, ineffective project specifications, and beneficiary disengagement. In this study, it is demonstrated how a positive social impact on housing could be the outcome of an improved self-help approach. Consequently, the research suggests the adoption of an effective self-help housing support model, which may effectively address the challenges posed by informal settlements while enhancing the execution of self-help housing projects. The model has the potential to make contemporary contributions to the public housing policy model in South Africa. This study contributes to the broader discourse on sustainable housing alternatives, providing insights into the various obstacles, potential advantages, and recommended strategies within the realm of selfhelp housing. The study's qualitative approach facilitated a comprehensive examination of the lived experiences and viewpoints of diverse stakeholders. This yielded valuable insights that can inform policymakers, practitioners, and communities in their efforts to improve the sustainability of self-help housing solutions in the central region of South Africa. , Thesis (PhD) -- Engineering, Built Environment and Technology, 2023
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  • Date Issued: 2023-12

Characterization of the coastal Aquifer of Gqeberha, South Africa : Developing a conceptual understanding

  • Authors: Vandala, Bamanye
  • Date: 2023-12
  • Subjects: Aquifers -- South Africa -- Port Elizabeth , Groundwater ecology , Hydrogeology
  • Language: English
  • Type: Master's theses , text
  • Identifier: http://hdl.handle.net/10948/62710 , vital:72932
  • Description: The aquifer systems in Gqeberha are poorly understood due to a lack of groundwater studies within the area, and this is particularly the case for the coastal aquifer of Gqeberha. Amidst the water crisis the city is currently facing, groundwater has become crucial, with over 1000 boreholes reportedly drilled in the coastal area, most of which are residential. This has resulted in the need to conduct more groundwater studies in the area and in Nelson Mandela Bay. This study presents a detailed hydrogeological characterization of the coastal aquifer of Gqeberha. This was achieved through the use of different techniques, which include field mapping, geophysics, hydrochemistry, and pumping test analysis. The work was done on the coastal seeps of the Algoa Group Formation and the fractured aquifer of the Peninsula Formation. The results through mapping indicated an abundance of folds, faults, and fractures which all have implications for groundwater flow. The majority of fractures are striking in the NE-SW and NW-SE directions. The pumping test analysis also indicated fractal flow with significant matrix flow resulting in a dual porosity system up to at least 200m in depth. The transmissivity and storativity values range from 6.78 – 44.5 m2/day and 0.0172 – 0.0325, respectively. This is highly dependent on the fracture interconnectivity, which varies across the area and is higher at shallow depths, as suggested by the geophysical profiles. Geophysical profiles indicate that the contact between the Algoa Group Formations and the Peninsula Formation results in coastal seeps due to the difference in hydraulic conductivities. The hydrochemical analysis suggests that the seeps generally have Na-Cl and Ca-Mg-Cl water types. The groundwater in the eastern area has a Ca-HCO3 water type, and the groundwater in the western region has a Ca-Mg-Cl water type, with the Chelsea-Noordhoek Fault system separating the two groundwater signatures. Groundwater at greater depths has a Na-Cl water type with higher TDS values. The chemical signatures seen are due to external factors, which include sea sprays, anthropogenic activities, rock-water processes, and possibly connate water in the Peninsula Formation aquifer. The findings of this study offer valuable insights into the present conditions of the aquifer in Gqeberha. This research serves as a foundational study that can provide a baseline for future hydrogeological investigations in the area. , Thesis (MSc) -- Faculty of Science, School of Environmental Sciences, 2023
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  • Date Issued: 2023-12

Chemical analysis and biological activities of crude extracts and essential oil of selected medicinal plants from the Eastern Cape, South Africa, and Volta Region of Ghana

  • Authors: Agbo, Irene Adzo
  • Date: 2023-12
  • Subjects: Medicinal plants , Lantana camara , Peptic ulcer -- Treatment , Traditional medicine - South Africa -- Eastern Cape , Traditional medicine -- Ghana
  • Language: English
  • Type: Master's theses , text
  • Identifier: http://hdl.handle.net/10948/62431 , vital:72728
  • Description: Lantana camara and Khaya grandifoliola extracts are among many plants found traditionally effective for the treatment of wounds and ulcers. This study assessed the phytochemical content, isolation and identification of single compounds from methanol and ethyl acetate extracts of Lantana camara and Khaya grandifoliola. Further, the bioactivity testing including antioxidant, antimicrobial and cytoxicity of the extracts was done to confirm the wound healing potential discovered by the traditional healers. Materials and methods: Extraction was done successively using maceration method with 100 % ethyl acetate and 100 % methanol with a biomass-to-solvent ratio of 1:3 (w/v) to obtain L. camara ethyl acetate extracts of berry (ELB), flower (ELF) and leaf (ELL) and methanol extracts of MLB, MLF, MLL and K. grandifoliola ethyl acetate extracts of leaf (EKL), root (EKR) and stem bark (EKSB) and methanol extracts of MKL, MKR, MKSB respectively. L. camara leaf essential oil (EO) was extracted using the hydro-distillation method with a Clevenger apparatus. Total phytochemical content was assessed for each extract using spectrophotometric methods and a calibration curve of standards: bromocresol green method with atropine; Folin–Ciocalteu colorimetric method with gallic acid, aluminium chloride colorimetric method with quercetin and concentrated sulphuric acid chloroform with linalool for total alkaloid, phenolic, flavonoid and terpenoid contents respectively. Single compound isolation and purification was conducted using chromatographic techniques. Elucidation of single compounds was done using spectrometric method, high resolution- mass spectrometry, and one and two-dimensional (1D and 2D)-NMR. Stereochemistry of each compound was confirmed using electronic circular dichroism spectra. A Crystalline compound was identified by single crystal X-ray diffraction using CuKα-radiation. In vitro bioactivities were assessed with methods such as 3-[4,5-dimethylthiazole-2-yl]-2,5-diphenyltetrazolium bromide, free radical scavenging activity of 1,1-diphenyl-2-picrylhydrazyl, inhibitory effect on nitric oxide production in lipopolysaccharide-activated RAW 264.7 macrophages, and 96-well plate micro dilution for cytotoxicity, ant-inflammatory and antimicrobial activity testing. Results: Methanol extracts of both plants retained high phytochemical concentrations of all the phytoconstituents investigated compared with the ethyl acetate extracts which retained lower concentrations. The results of the L. camara methanol extracts include; total alkaloid content (TAC) (2.05±0.18, 1.87±1.54 and 2.60±1.10 mg AEQ/100 mg); total phenolic content (TPC) (14.05±4.04, 34.59±3.01 and 18.58±1.87 mg GAEQ/100 mg); the total flavonoid content(TFC) of flower (12.45±1.87, 20.41±2.69 and mg QEQ/100 mg); total terpenoids (TTC) (20.74±2.34, 20.74±2.34 and 15.97±1.19 mg LIN EQ/100mg) of MLB, MLF and MLL respectively. Whereas that of the K. grandifoliola methanol extracts include; TAC (7.32±0.14,8.49±0.34, 10.67±0.22 mg AEQ/100 mg); TPC (37.49±1.40, 44.41±0.69, 53.57±1.50 mgGAEQ/100 mg); TFC (6.54±0.55, 9.58±0.89 and 10.26±0.92 mg QEQ/100 mg); TTC(10.16±1.41, 35.78±2.14 and 23.45±1.76 mg LIN EQ/100mg) of MKL, MKR and MKSB respectively. The major components of essential oil, out of the 71 constituents identified include Davanone D (32.91 %), Caryophyllene (5.07 %), Nerolidol 2 (3.56 %) and GermacreneD (3.13 %). Compounds 3.47 was isolated from the methanol extract of L. camara flowers. This compound is reported for the first time from the L. camara flower extract. Two compounds, compounds 4.23, and 4.26, were isolated from the methanol extract of K. grandifoliola roots, compound 4.22 was isolated from the ethyl acetate root extract while compounds 4.24 and 4.25 were isolated from the ethyl acetate stem bark extract as isomers in a mixture. Compounds 4.22 and 4.23 are reported from K. grandifoliola root for the first time. The isolated compounds (compounds 3.47 and 4.23) were nontoxic to the Vero cell line and this may contribute to possible stimulation of cell proliferation, promoting wound healing. Cytotoxicity describes extract virulence to Vero cell line. MLF and ELB were found nontoxic even at the highest concentration of 200 μg/mL. The MKSB and MKR, as well as the EKSB were nontoxic. Antioxidant activity results, described by the percentage inhibition in the DPPH assay, showed that MLF and MKSB had the highest antioxidant activities compared with the ascorbic acid standard, with IC50 of 38.68±5.09 and 37.03±11.95 μg/mL for L. camara and K. grandifoliola respectively. ELB exhibited a significant anti-inflammatory activity inhibiting NO• radical generation in the LPS-stimulated RAW 264.7 macrophages at concentration ranging from 50 and 100 μg/mL. EKSB and MKR showed significant anti-inflammatory activity at 100 and 200 μg/ml respectively. ELL and ELF demonstrated potent growth inhibition against S. pyogenes with an MIC value ≤ 0.125 mg/mL, while the MICs of the ELB and MLL were 0.5 mg/mL and 2 mg/mL respectively. MKSB and MKR and EKSB extract exhibited an effective growth inhibition against S. aureus with MIC of 1 mg/mL. The growth of S. pyogenes was supressed by both ethyl acetate and methanol extracts of all plant parts tested with MIC ranging from 0.25–2 mg/mL. Conclusion: The potent bioactivity shown in the results of the cytotoxicity, antioxidant activity, anti-inflammatory and antimicrobial activity testing, and the nontoxic singlecompounds of L. camara and K. grandifoliola extracts led to the conclusion that the two plants had wound healing potential. The study therefore confirmed their traditional uses for treatment of wounds. , Thesis (PhD) -- Faculty of Science, School of Biomolecular and Chemical Sciences, 2023
  • Full Text:
  • Date Issued: 2023-12
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