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Enhancing licence plate recognition for a robust vehicle re-identification system

- Boby, Alden Zachary

Authors: Boby, Alden Zachary
Date: 2024-10-11
Subjects: Automobile theft South Africa , Deep learning (Machine learning) , Object detection , YOLOv7 , YOLO , Pattern recognition systems , Image processing Digital techniques , Automobile license plates
Language: English
Type: Academic theses , Master's theses , text
Identifier: http://hdl.handle.net/10962/464322 , vital:76501
Description: Vehicle security is a growing concern for citizens of South Africa. Law enforcement relies on reports and security camera footage for vehicle identification but struggles to match the increasing number of carjacking incidents and low vehicle recovery rates. Security camera footage offers an accessible means to identify stolen vehicles, yet it often poses hurdles like anamorphic plates and low resolution. Furthermore, depending on human operators proves inefficient, requiring faster processes to improve vehicle recovery rates and trust in law enforcement. The integration of deep learning has revolutionised object detection algorithms, increasing the popularity of vehicle tracking for security purposes. This thesis investigates advanced deep-learning methods for a comprehensive vehicle search and re-identification system. It enhances YOLOv7’s algorithmic capabilities and employs preprocessing techniques like super-resolution and perspective correction via the Improved Warped Planar Object Detection network for more effective licence plate optical character recognition. Key contributions include a specifically annotated dataset for training object detection models, an optical character recognition model based on YOLOv7, and a method for identifying vehicles in unrestricted data. The system detected rectangular and square licence plates without prior shape knowledge, achieving a 98.7% character recognition rate compared to 95.31% in related work. Moreover, it outperformed traditional optical character recognition by 28.25% and deep-learning EasyOCR by 14.18%. Its potential applications in law enforcement, traffic management, and parking systems can improve surveillance and security through automation. , Thesis (MSc) -- Faculty of Science, Computer Science, 2024
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Date Issued: 2024-10-11

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Evaluating baculovirus mixtures against false codling moth Thaumatotibia leucotreta Meyrick. (Lepidoptera: Tortricidae)

- Tole, Siviwe

Authors: Tole, Siviwe
Date: 2024-10-11
Subjects: False codling moth Biological control , Baculoviruses , Integrated pest management , Natural pesticides , Granulovirus
Language: English
Type: Academic theses , Master's theses , text
Identifier: http://hdl.handle.net/10962/463996 , vital:76464
Description: False codling moth (FCM), Thaumatotibia leucotreta, is an important pest of citrus, stone fruit, avocados, peppers, and other important agricultural crops in southern Africa. Baculovirus-based biopesticides are components in an integrated pest management (IPM) programme to manage the pest in the field. Cryptogran™ and Cryptex™ which are CrleGV-SA based-biopesticides have been effective in the control of T. leucotreta for the past 15 years. Recently, CrpeNPV-based Multimax™ and Codlmax™ have been commercialised to control T. leucotreta and other important agricultural pests. Despite these viruses being relatively host-specific and safe to humans and animals in comparison to chemical insecticides, their application is hindered by their slow speed of kill, sensitivity to UV light, and the potential for insect resistance. Research investigating the effects of mixed baculoviral interactions against target pests has been a growing field of interest due to their potential to overcome such shortcomings. Previous studies using a combination of CrleGV-SA and CrpeNPV against T. leucotreta observed a reduction in lethal concentration in laboratory bioassays, indicating that such mixtures may have the potential for application in the field. This has led to the motivation to investigate further interactions between CrleGV-SA in combination with CrpeNPV, CpGV-M, and HearNPV-Au to understand better how these viruses interact and to determine whether synergistic, additive, or antagonistic interactions can occur against T. leucotreta. The outcome of these interactions will inform researchers and farmers about best practices concerning these viruses should they be combined against T. leucotreta in the future. Prior to performing mixed baculovirus infections in laboratory bioassays, oligonucleotides targeting unique regions in the viral genomes of CrleGV-SA, CrpeNPV, CpGV-M, and HearNPV-Au were designed using Primer-BLAST. The specificity of these oligonucleotides was further tested in silico using Geneious R11 software (11.1.5). The stocks of CrpeNPV, CpGV-M, and HearNPV-Au were purified using crude OB extraction from diseased C. peltastica, C. pomonella, and H. armigera larval cadavers provided by River Bioscience (Pty) Ltd (Gqeberha, South Africa). The stock of CrleGV-SA was purified using crude OB extraction from infected T. leucotreta cadavers. Subsequently, the unique oligonucleotides were used in PCR assays to detect if the samples contained the baculoviruses of interest. Amplicons of the expected sizes were generated indicating the presence of CrleGV-SA, CrpeNPV, CpGV-M, and HearNPV-Au in each of the samples. The OBs were counted using darkfield microscopy and a counting chamber before the single and mixed infections were initiated against T. leucotreta neonate larvae. Surface-dose biological assays were used to evaluate the relative virulence in terms of lethal concentration of CrleGV-SA, CrpeNPV, and CpGV-M, alone against T. leucotreta. After 7 days, the dose mortality data was analysed using “drc” in R studio and the LC50 and LC90 were compared amongst each virus. The CrleGV-SA treatment was estimated to be the most virulent in comparison to CrpeNPV and CpGV-M. A dose discriminate assay confirmed that HearNPV does not cause mortality in T. leucotreta. Similarly, the relative virulence in terms of lethal concentration of CrleGV-SA in various ratios in combination with CrpeNPV, CpGV-M, and HearNPV-Au was determined using 7-day surface dose biological assays. The CrleGV/CrpeNPV was the most virulent mixture with lower LC50 and LC90 values measured in comparison to CrleGV/CpGV and CrleGV/HearNPV, respectively. The Tammes Bakuniak graphic method confirmed the CrleGV/CrpeNPV, CrleGV/CpGV, and CrleGV/HearNPV mixtures to be antagonistic against T. leucotreta neonate larvae in terms of lethal concentration. The last aspect of the study was to determine the probable cause of larval death. A modified CTAB protocol was used to extract genomic DNA from neonate-sized T. leucotreta cadavers collected in single and mixed infection assays. The gDNA served as templates in PCR assays using the unique oligonucleotides. In single infections, the presence of CrleGV-SA in CrpeNPV and HearNPV inoculated larvae was observed. The results suggest possible covert infections of CrleGV-SA in the T. leucotreta colony which may be caused by virus infection or an unknown stress factor. The results from the mixed infections showed the presence of each virus in all replicates except for the CrleGV/CpGV and CrleGV/HearNPV mixtures. In the CrleGV/CpGV mixture, only CrleGV-SA was present in the last replicate, suggesting a possible competition for host resources. In the CrleGV/HearNPV mixture, only CrleGV-SA was detected in all 3 replicates, suggesting that HearNPV did not have any effect and the larvae died of the CrleGV-SA infection. This is the first study to report mixtures of CrleGV-SA in combination with CpGV-M and HearNPV-Au against T. leucotreta neonate larvae. Despite the antagonistic interactions observed in the evaluated mixtures, this study has laid a foundation to further investigate how these viruses interact in dual infections for the improved control of T. leucotreta. This may be done by evaluating different ratios and combinations of baculoviruses to those used in this study. , Thesis (MSc) -- Faculty of Science, Biochemistry, Microbiology & Bioinformatics, 2024
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Date Issued: 2024-10-11

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Evaluation of traditional and residual momentum strategies during the Covid period on the Johannesburg Stock Exchange

- Yengwa, Mphathi Lubabalo

Authors: Yengwa, Mphathi Lubabalo
Date: 2024-10-11
Subjects: Uncatalogued
Language: English
Type: Academic theses , Master's theses , text
Identifier: http://hdl.handle.net/10962/462834 , vital:76339
Description: Traditional momentum is a concept which was first discovered by Jegadeesh and Titman (1993), defined as a tendency of stocks to experience a continuation in their relative performance. A stock that performed relatively well will continue to perform relatively well, and vice versa. It has been observed by other researchers that during market crises, traditional momentum tends to produce large negative returns for investors, defined as a momentum crash. To mitigate momentum crashes, many researchers have developed new momentum strategies which have better performance than traditional momentum during market crises; such strategies include residual momentum. While both residual and traditional momentum have been studied in international markets and locally, the performance of both the residual and traditional momentum strategies have not been examined in the most recent Covid-fuelled financial crisis on the Johannesburg Stock Exchange. The study compares the performance of hypothetical long-only winner traditional and residual momentum portfolios (from 2018–2022) using various risk metrics, which include the tracking error, Sharpe ratio, Jensen’s alpha and information ratio. To compare the statistical significance of the difference in mean returns of residual and traditional momentum strategies to the benchmark (FTSE/Johannesburg Stock Exchange (JSE) Top 40) the study uses Welch’s t-test. The study uses an Auto regressive distributed lag (ARDL) regression to examine the effect that various market conditions (bull market, bear market and extreme volatility) have on the returns of residual and traditional momentum strategies. Given the limited period examined in this study, the Monte Carlo simulation was used to extrapolate potential outcomes of how the momentum strategies might perform under different market conditions (as mentioned) in 1 000 iterations of each condition. The simple return analysis undertaken in this research revealed that traditional momentum outperformed residual momentum both before and throughout the COVID period. In the risk-adjusted performance measures, traditional momentum outperformed at all four risk indicators during the 2020 COVID year. The statistical significance tests, which compared the strategies' mean returns to the benchmark, demonstrated no statistically significant difference in returns over the COVID year. Furthermore, when evaluating the strategies over a five-year period (2018-2022), the difference in mean returns was shown to be statistically insignificant. However, statistical significance in returns was shown in some individual years. The ARDL regression findings show that bull, bear, and volatility factors explain relatively little of the returns for both momentum strategies, which is consistent with previous research. The Monte Carlo simulation, using the bear variable, forecasted that traditional momentum would result in negative returns during market declines, but residual momentum would provide positive returns and surpass traditional momentum with a probability of 26%. When using the bull variable, the simulation discovered that both traditional and residual momentum strategies resulted in positive returns. However, the residual momentum strategy outperformed in terms of returns and had an 84% likelihood of outperforming the traditional momentum strategy across 1,000 iterations. Nevertheless, when the simulation included the volatility variable, it projected negative returns for residual momentum and positive returns for traditional momentum. Additionally, it estimated a 14% probability of residual momentum surpassing traditional momentum under volatile market circumstances. , Thesis (MCom) -- Faculty of Commerce, Economics and Economic History, 2024
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Date Issued: 2024-10-11

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Exploring fatigue challenges and contributing factors in the South African aviation industry amidst the COVID-19 pandemic: insights from blunt-end stakeholders

- Clark, Darryl Malcolm

Authors: Clark, Darryl Malcolm
Date: 2024-10-11
Subjects: Fatigue , Aircraft industry South Africa , COVID-19 Pandemic, 2020- Influence , Executives Attitudes , Fatigue in the workplace , Aeronautics Law and legislation South Africa
Language: English
Type: Academic theses , Master's theses , text
Identifier: http://hdl.handle.net/10962/464743 , vital:76541
Description: Background: Despite the global aviation industry's ongoing commitment to safety, crew fatigue remains a persistent and pressing issue. Within South Africa, fatigue management was primarily governed by regulations, however, there was ongoing debate about whether these regulations adequately reflected the latest scientific evidence and operational demands. This study addressed this gap by investigating perceptions about fatigue and fatigue management from management and decision-makers (blunt-end stakeholders) within the South African aviation sector. This study aimed to investigate the perceptions surrounding fatigue and fatigue management among management and decision-makers (blunt-end stakeholders) within the South African aviation sector. Specifically, it sought to contribute to ongoing research dedicated to developing a better understanding of whether, how, and why regulations pertaining to fatigue management may need to change. By exploring the perspectives of blunt-end stakeholders, the study aimed to uncover insights into the challenges and potential gaps in current regulations, with the ultimate goal of informing potential regulatory adjustments to enhance aviation safety. Methodology: A cross-sectional, qualitative exploratory design investigated perceptions about fatigue and fatigue management among blunt-end stakeholders in the South African aviation industry. Data was collected through online semi-structured interviews and written open-ended questionnaires to capture diverse perspectives. The methodology aimed to comprehensively understand fatigue-related experiences and perceptions among pilots and cabin crew, considering the unique challenges posed by the COVID-19 pandemic. Participants were selected using purposive and snowball sampling, ensuring representation from various regulatory categories and industry sectors. The study employed a thematic analysis approach to analyse data collected through online semi-structured interviews and written open-ended questionnaires. Thematic analysis facilitated the identification of key patterns and themes in the perceptions of blunt-end stakeholders within the South African aviation industry regarding fatigue and fatigue management Results: The thematic analysis of data from thirteen South African aviation industry stakeholders unveiled insights into crew fatigue challenges and regulatory concerns. Participants emphasized crew fatigue as a significant safety risk linked to entrenched crew mentalities, where instances of disregarding fatigue management protocols posed imminent safety risks. Additionally, outdated regulations were cited, hindering optimal crew rest periods and modern fatigue mitigation technologies, with discrepancies in regulatory support exacerbating challenges across operational contexts. Aviation stakeholders expressed apprehensions regarding the efficacy of existing Flight and Duty Regulations, advocating for amendments to enhance fatigue management practices. The COVID-19 pandemic further exacerbated fatigue issues, leading to shifts in crew morale, increased stress levels, and regulatory challenges, necessitating adaptive fatigue management strategies and proposed risk mitigation plans, including regulatory adjustments and enhanced stakeholder engagement. Discussion: The study investigated the intricate landscape of fatigue-related risks within the aviation industry, recognizing the systemic and context-specific nature of these challenges. It is evident from our findings, in line with previous research, that fatigue within the aviation sector is not merely an isolated issue but a multifaceted consequence of systemic factors. Our study highlights the pressing need for revisiting the current Flight and Duty Periods (FDPs) and overall fatigue management strategies to address these underlying systemic issues effectively. Unlike static safety concerns, fatigue-related risks evolve dynamically, influenced by technological advancements, industry practices, and external factors such as the ongoing COVID-19 pandemic. Our analysis elucidated the complex interplay between safety protocols, operational standards, and the well-being of crew members, emphasizing the need for a nuanced approach in mitigating fatigue-related risks. Central to our findings is the recognition of the limitations of existing regulations in adequately addressing emerging challenges associated with crew fatigue. Our study underscores the imperative of regulatory agility in safeguarding both passengers and crew members, advocating for continuous evaluation and refinement of regulatory frameworks. Specifically, there is a critical need to revisit and adapt current FDPs and fatigue management strategies to align with the systemic causes of fatigue identified in our research. Conclusion: This study contributed a comprehensive analysis of crew fatigue in South African aviation, focusing on perspectives of blunt-end stakeholders. It highlighted widespread recognition of fatigue's safety implications, exacerbated by factors like economic stressors and regulatory deficiencies, including those intensified by the COVID-19 pandemic. Participants advocated for regulatory reforms to enhance crew rest provisions and address scheduling challenges. The research underscored the need for a proactive, collaborative approach prioritizing aviation professionals' well-being. Recommendations emphasized tailored regulations, technology integration, and ongoing collaboration among stakeholders to refine fatigue management strategies and ensure industry resilience. , Thesis (MSc) -- Faculty of Science, Human Kinetics and Ergonomics, 2024
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Date Issued: 2024-10-11

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Exploring food waste narratives and perceptions in print media and in the urban community of Makhanda, in the Eastern Cape, South Africa

- Dlamini, Zinhle Nkululeko

Authors: Dlamini, Zinhle Nkululeko
Date: 2024-10-11
Subjects: Uncatalogued
Language: English
Type: Academic theses , Master's theses , text
Identifier: http://hdl.handle.net/10962/464798 , vital:76546
Description: Food waste (FW) is a global issue that has gained increasing attention in recent decades. There has been more research to identify the multi-layered causes and effects of this issue. A vast number of studies focus on the quantification of FW, its drivers, and causes. While quantifying the amount of FW being generated is important in revealing the scope of the problem, there are many aspects of FW that are still not as widely covered i.e., the socio-cultural component of FW. This is because first and foremost what is considered food, and what is considered FW is influenced by the sociocultural context in which it is obtained, prepared, and consumed. The socio-cultural context of a society cannot be studied properly without looking at the way the people that practice those specific societal norms and cultural practices think and perceive things. Perceptions are important because sociocultural behaviours and practices tend to be reproduced in correlation to how they are perceived. Thus, if the socio-cultural dimension of FW is to be dissected, one needs to look at the socialisation agents that affect the cultural context. A socialisation agent that has been cited as growing in influence and enjoying unprecedented access in human society is the media. Despite the proven influence of the media on perceptions and behavioural patterns, the sheer volume of studies that look at the linkages between media and topics such as FW is limited. in the context of the Global South, particularly in South Africa. In response to this research gap, I set out to examine the types of narratives and perceptions that print media and media consumers within an urban community have about FW. Since the study is centred around print media perceptions and narratives and those of the community, the study used a mixed-method approach that comprised of a media analysis, one-onone, semi structured interviews, key informant discussions as well as food focus groups. Thirty six respondents were interviewed with semi-structured one on one interviews, a further six respondents were key informants, they too were interviewed with one on one semi-structured interviews. Lastly, 16 were participants in the focus sessions, and each session comprised of 8 randomly selected participants. To procure the FW perceptions and narratives of print media and the people of Makhanda, the study was divided into three phases. Phase one comprised of a print media analysis through an archival media platform of SABINET. Phase two comprised of two food focus group sessions; phase three of the study comprised of the semi-structured interviews with 36 interviewees representing the general public and six with key informants. To make sense of the results obtained from the print media analysis, the study used the agenda setting framework and found that that the representation of FW content in print media was limited. Through the use of thematic analysis, 14 viii FW perceptions and narratives were identified in print media (and perceptions and narratives are used interchangeably, therefore 14 themes equals 14 FW perceptions and narratives). Of these 14 themes there were some that were more frequently presented than others. The most frequently presented perceptions and narratives in print media were the FW and food insecurity/hunger, FW and morality and FW and the economy. The study also found that a bulk of the FW content disseminated by print media belonged to a relatively few publications namely: Cape Argus, The Star, the Mail and Gurdian and the Daily Dispatch. These findings reinforced that FW perceptions and narratives in print media were not only disproportionally represented but were also disseminated by a limited pool of media content creators. The study found that Makhanda respondents used and preferred other media forms outside of print media i.e., radio and television. Respondents maintained that the media form they were the least exposed to and least preferred was print media (newspapers). From the 58 respondents, only seven respondents indicated that they listened to and preferred radio more than any other media form, and only two respondents noted that they read newspapers. In contrast, 24 respondents noted that they preferred and were more exposed to television than any other media form. In addition, respondents noted that they saw and heard a limited amount of FW content on the media that they were most exposed to. Instead, they noted that they were more exposed to content that encouraged them to procure and consume food, such as food advertisements. On average, individuals that were exposed to and preferred radio reported to hearing more FW content as opposed to individuals that preferred television. For instance, from the seven respondents that preferred and were most exposed to radio, four of them noted that they had heard a lot of FW content. While 17 of the 24 respondents that preferred and were most exposed to television, maintained that they did not recall seeing any FW content. The study also found that Makhanda respondents had a number of perceptions and narratives about FW, that were converted into themes using content and thematic analysis. The study found that Makhanda respondents had a total of 15 FW perceptions and narratives. Just like in the media analysis there were some perceptions and narratives that were emphasised and more frequently mentioned than others. The three most dominant themes were: affluence, FW and hunger, and FW and morality. Furthermore, the research also found that the perceptions and narratives of respondents were influenced by a variety of external and internal factors such as socio-economic status/affluence, gender, age, race, and media preference. These factors interacted with each other and varied in their significance from one respondent to the other. By far, the aspect shown to be the most influential in shaping respondents FW perceptions and narratives was affluence. Twentyeight respondents spoke about the economic drawbacks of FW and cited as reason for not engaging viii in FW. In addition to this, there were some respondents that maintained that FW did not occur amongst people who belonged to the lower socio-economic class and that rather, the phenomena were limited to those who were more affluent. In speaking about affluence, respondents e linked FW with other aspects such as race, gender, age, and media preference. For instance, in addition to claiming that FW was only limited to affluent households, other respondents felt that wasting food was a luxury the only white people participated in. Such claims highlight the idea that the sociocultural historical context of South Africa is one that has some influence in the FW perceptions and narratives of Makhanda respondents. The study found that there was little overlap in the types of perceptions and narratives that print media and the Makhanda respondents have about FW. From the 14 and 15 perceptions and narratives found between each realm there were only three thematic overlaps namely: the theme of affluence, morality and FW and food insecurity. This limited overlap of perceptions and narratives suggest that there is a disconnection present between the perceptions and narratives of print media and those that are exhibited by Makhanda respondents. , Thesis (MSc) -- Faculty of Science, Environmental Science, 2024
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Date Issued: 2024-10-11

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Exploring how visual models can be used in teaching mathematics for growing a productive disposition in Grade 9 learners

- Shetunyenga, Fillipus Shetunyenga

Authors: Shetunyenga, Fillipus Shetunyenga
Date: 2024-10-11
Subjects: Uncatalogued
Language: English
Type: Academic theses , Master's theses , text
Identifier: http://hdl.handle.net/10962/463625 , vital:76426
Description: The Namibian Curriculum for Basic Education states clearly that Indigenous Knowledge (IK) should be integrated into science teaching. However, the irony is that it does not give clear pedagogical guidelines on how it should be integrated. The implication is that the curriculum assumes that all teachers are aware of how to integrate IK into their teaching. This assumption has therefore led to little or no integration of IK in many classrooms in Namibia, something which could be in part a contributing factor to poor learners’ academic performance in science subjects and Agricultural Science in particular. This tension in the curriculum plus the apparent gap in the literature regarding the integration of IK has triggered my interest to conduct this interventionist qualitative case study. Essentially, this study aimed to explore affordances and/or hindrances when using the indigenous technology of organic crop farming to mediate learning in Grade 12 Agricultural Science classes in peri-urban schools in the Oshana region in Namibia. The study was underpinned by the interpretivist and Ubuntu paradigms. Vygotsky’s (1978) socio-cultural theory and Shulman’s (1986) pedagogical content knowledge (PCK) framework were used as lenses to analyse my data. Within PCK, I also used Mavhunga and Rollnick’s (2013) Topic-Specific PCK as an analytical framework. The findings of the study revealed that the integration of Indigenous knowledge in Agricultural Science education has great potential in improving both the teaching and learnng of science. It also revealed that the Agricultural Science teachers were positive towards the integration of IK in their lessons. However, they conceded that they lacked pedagogical insights on how to integrate IK as they were never trained on how to integrate it. As a result, they found the presentations by the Indigenous Knowledge Custodians (IKCs) informative and shed light on how they could integrate IK during teaching and learning. That is, they became cultural knowledge brokers making science relevant and accessible to their learners. The study thus recommends that teacher training institutions should modify the curriculum to include a pedagogy course module on IK to equip students with the essential PCK on IK integration in science teaching. , Thesis (MEd) -- Faculty of Education, Secondary and Post-School Education, 2024
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Date Issued: 2024-10-11

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Exploring Pedagogies that teachers draw on to teach reading in Grade 10 English First Additional Language inclusive classes

- Ndlovu, Sheillah

Authors: Ndlovu, Sheillah
Date: 2024-10-11
Subjects: Uncatalogued
Language: English
Type: Academic theses , Master's theses , text
Identifier: http://hdl.handle.net/10962/463746 , vital:76437
Description: This qualitative, interpretive study explored the pedagogies teachers drew on to teach reading in Grade 10 English First Additional Language inclusive classes. Over the years, children with learning difficulties have been excluded from formal learning and placed in special schools. However, the transformation through inclusive education allows learners with learning difficulties to be enrolled in mainstream schools. Unfortunately, mainstream teachers were not trained to address learning difficulties. It is for this reason that this study explored the pedagogies that teachers drew on to teach reading through an exploratory case study of five teachers and grade 10 learners, noting responses of learners with learning difficulties at one school in John Taolo Gaetsewe (JTG) district in Northern Cape. This study was guided by Sen’s capability approach. Semi-structured interviews, focus group interviews, and non-participant observations were used to collect data on the pedagogies teachers draw on to teach reading in inclusive classes and learners' views on how they want to be taught reading. The collected data was analysed through a thematic data analysis approach with the hope that the findings will help to develop and enrich teachers in teaching reading in inclusive classes to engage all learners. Findings revealed that the participating teachers drew from various pedagogies such as Reading to Learn, Establishing, Maintaining, and Consolidating, and Question-Answer- Relationship. The similarities among these pedagogies are their repetitive nature and that they provide maximum opportunities for learners with various needs, abilities, and challenges to succeed. The teachers’ self-developed strategies were influenced by the need to promote Ubuntu and collaborative learning. Knowing learners and their weaknesses was key to developing strategies. Teachers can draw from various pedagogies to teach reading in an inclusive class. This study recommends using multimodal texts, compulsory inclusive education during initial teacher education, and combined use of pedagogies. , Thesis (MEd) -- Faculty of Education, Institute for the Study of Englishes of Africa, 2024
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Date Issued: 2024-10-11

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Exploring self-directed continuous professional development for English Language teachers in selected Namibian secondary schools

- Amakutuwa, Hilma Ndesheetelwa Mwalengwa

Authors: Amakutuwa, Hilma Ndesheetelwa Mwalengwa
Date: 2024-10-11
Subjects: English language Study and teaching Namibia , English teachers Namibia , Continuing professional development , Self-managed learning , Reflective practice
Language: English
Type: Academic theses , Master's theses , text
Identifier: http://hdl.handle.net/10962/463538 , vital:76418
Description: Continuous professional development (CPD) for teachers, with all its diverse notions, has been noted and articulated in various policy documents in Namibia, and is understood as in-service training and professional development for teachers to improve learning outcomes. In Namibia, challenges have been experienced with the performance of learners in English as a Second Language (ESL) at the national level, and teacher professional development could be one way of changing the status quo. However, in answer to the call from the Namibian Ministry of Education Arts and Culture for a more idiosyncratic orientation, limited literature was found on how ESL teachers use self-directed learning (SDL) to shape their CPD activities. Thus, the purpose of this study was to address this gap by exploring the self-directed CPD needs of English Language teachers in selected Namibian secondary schools. The study was oriented to theoretical insights from SDL, reflective practice and social constructivism. Through the use of a qualitative approach, the study employed an exploratory case study research design. Semi-structured interviews and focus group discussions were used to generate data from eight selected Grade 8 to 12 ESL teachers in the Khomas region of Namibia. The data gathered were analysed using an inductive thematic framework. The findings of the study indicate that ESL teachers are faced with a myriad of challenges ranging from classroom experiences, the type of learners they work with and the support system available at school, regional and national level. The study found that due to changing education paradigms, ESL teachers need to broaden their knowledge base in specialised education and systematic professional interventions at school level. They indicated that this would help learners with challenges in reading, writing and comprehension to improve their skills in ESL classrooms. They further emphasised the necessity for mentors, education specialists, systematic schools and circuit based collaborative CPD, as well as more support from school heads and regional ESL senior education officers, which is an area that is inadequately managed. Finally, they pointed out that in order to make their ESL classes engaging and enjoyable, teachers needed to have a strong foundation in ICT education. This foundation can be leveraged to create resources that are now lacking. The findings have implications for ESL teachers, school administrators, education specialists and policymakers, as they provide insights and recommendations for enhancing ESL education practices. , Thesis (MEd) -- Faculty of Education, Secondary and Post-School Education, 2024
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Date Issued: 2024-10-11

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Exploring social learning practices for catchment management: a case study of two catchments in South Africa

- Siyengo, Kwanele

Authors: Siyengo, Kwanele
Date: 2024-10-11
Subjects: Uncatalogued
Language: English
Type: Academic theses , Master's theses , text
Identifier: http://hdl.handle.net/10962/464848 , vital:76550
Description: Social learning is achieved through a wide range of practices and is understood in different ways through multiple definitions in the literature. It is recognised as an outcome of stakeholder engagement through collaborative activities such as catchment management. Stakeholder engagement and collaboration in catchment management helps stakeholders understand the complex systems they work in, by enabling deliberation, dialogue, knowledge sharing and interdependencies. These are seen as processes which enable not only the sustainable use of natural resources but also help to achieve outcomes of transformative social learning. In partnership with the Living Catchments Project (implemented by the South African National Biodiversity Institute - SANBI), this study explores social learning practices and facilitation – and the role these play for transformation. Exploring two case studies, the Olifants River catchment and the Umzimvubu River catchment, the study adopted a qualitative participatory case study approach. It used observations, semi-structured interviews and reflections to look at the social learning practices in the two catchments. Additionally, it made use of the Social Learning, Knowledge Management and Mediation (SLKMM) framework as an analytical tool to investigate social learning practices and tools in the cases and explore how support for these can be enhanced in future. The results showed that there are existing social learning platforms and facilitation practices in the two catchments. Though not often explicit, social learning exists, and various tools (analytical, visual, participatory, and conceptual) and practices can be used to facilitate social learning. The greatest challenge for transformative social learning in these catchments is the need for a monitoring and evaluation practice which documents and makes explicit important learning and transformation taking place. This is therefore why, through a set of recommendations, it is suggested that it is key to build capacities within existing facilitators and to work closely with stakeholders from research, policy, and implementation to grow the existing social learning work, for future transformation. , Thesis (MSc) -- Faculty of Science, Environmental Science, 2024
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Date Issued: 2024-10-11

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Exploring the influence of power dynamics on collaborative governance in the Thukela Catchment

- Dunyana, Philisa

Authors: Dunyana, Philisa
Date: 2024-10-11
Subjects: Uncatalogued
Language: English
Type: Academic theses , Master's theses , text
Identifier: http://hdl.handle.net/10962/464809 , vital:76547
Description: South Africa is a water-scarce country with unequally distributed water. This dilemma has been brought about by insufficient water supply and governance fragmentation, among other drivers. The democratic national water policies (National Water Act No. 36 of 1998) intend to foster collaborative water governance (CWG), where stakeholders within catchments must come together to learn and share decision-making responsibility through collaborative platforms that should ensure the sustainability and equitable distribution of water resources. Still, CWG is not functioning well in most parts of the country, partly due to power dynamics that compromise dynamics on collaborative governance processes and outcomes in the Upper Thukela Catchment (UTC). It did this by identifying the roles of stakeholders, looking into the nature of power dynamics among stakeholders and how these affect collaborative processes, and by examining how power dynamics interact with resources and mechanisms to influence collaborative governance outcomes. The research used two interrelated conceptual frameworks (Franks and Cleaver (2007) and the 4Rs framework (Mayers, 2005)) to explore power dynamics. The study was conducted through qualitative research using a case study approach, which consists of data collection methods such as in-depth semi-structured interviews, document review, direct observation and participant observation. The 4Rs framework highlighted the insufficient involvement of critical stakeholders in water governance, specifically those from the public sector with water management and governance authority rights. The analysis also exposed conflicting relationships among stakeholders involved in water governance, mostly stemming from some public sector stakeholders evading roles and responsibilities, a lack of trust, and limited access to information. These factors contribute to challenges and tensions within the water governance landscape in the UTC. The research also showed that the presence of different political parties in the water governance and management space seems to be the primary roots of the power dynamics that affect the processes of water governance and management. Political parties contesting power over the same communities led to conflict, corruption, competition, negligence, and sabotage. These challenges impact operational flow, service delivery, sense of urgency, and decisionmaking. Thus, the nature of power dynamics in collaborative governance processes further exposed the underlying issue of limited statehood. Application of the Franks and Cleaver (2007) framework revealed that through their influence on power dynamics, resources and mechanisms of access affect livelihoods and catchment outcomes. The study contributes to the body of knowledge on the influence of power dynamics on collaborative governance and provides recommendations for further studies to improve collaborative water governance. It highlights the complex interplay between power dynamics, stakeholder participation, and water governance processes in the UTC. To improve collaborative water governance, it is crucial to address limited stakeholder participation, mitigate the negative influence of political parties, and meaningfully empower local communities. , Thesis (MSc) -- Faculty of Science, Environmental Science, 2024
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Date Issued: 2024-10-11

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Extreme value theory with applications in finance

- Matshaya, Aphelele

Authors: Matshaya, Aphelele
Date: 2024-10-11
Subjects: Uncatalogued
Language: English
Type: Academic theses , Master's theses , text
Identifier: http://hdl.handle.net/10962/465047 , vital:76568
Description: The development and implementation of extreme value theory models has been very significant as they demonstrate an application of statistics that is very much needed in the analysis of extreme events in a wide range of industries, and more recently the cryptocurrency industry. The crypto industry is booming as the phenomenon of cryptocurrencies is spreading worldwide and constantly drawing the attention of investors, the media, as well as financial institutions. Cryptocurrencies are highly volatile assets whose price fluctuations continually lead to the loss of millions in a variety of currencies in the market. In this thesis, the extreme behaviour in the tail of the distribution of returns of Bitcoin will be examined. High-frequency Bitcoin data spanning periods before as well as after the COVID-19 pandemic will be utilised. The Peaks-over-Threshold method will be used to build models based on the generalised Pareto distribution, and both positive returns and negative returns will be modelled. Several techniques to select appropriate thresholds for the models are explored and the goodness-offit of the models assessed to determine the extent to which extreme value theory can model Bitcoin returns sufficiently. The analysis is extended and performed on Bitcoin data from a different crypto exchange to ensure model robustness is achieved. Using Bivariate extreme value theory, a Gumbel copula is fitted by the method of maximum likelihood with censored data to model the dynamic relationship between Bitcoin returns and trading volumes at the extreme tails. The extreme dependence and correlation structures will be analysed using tail dependence coefficients and the related extreme correlation coefficients. All computations are executed in R and the results are recorded in tabular and graphical formats. Tail-related measures of risk, namely Value-at-Risk and Expected Shortfall, are estimated from the extreme value models. Backtesting procedures are performed on the results from the risk models. A comparison between the negative returns of Bitcoin and those of Gold is carried out to determine which is the less risky asset to invest in during extreme market conditions. Extreme risk is calculated using the same extreme value approach and the results show that Bitcoin is riskier than Gold. , Thesis (MSc) -- Faculty of Science, Statistics, 2024
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Date Issued: 2024-10-11

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Foundation phase teachers’ understanding and implementation of differentiated pedagogical practices in teaching reading

- Muroa, Johanna Makgati

Authors: Muroa, Johanna Makgati
Date: 2024-10-11
Subjects: Uncatalogued
Language: English
Type: Academic theses , Master's theses , text
Identifier: http://hdl.handle.net/10962/463713 , vital:76434
Description: Pre-1994, teacher education in South Africa was separated into mainstream and special education classes. Special education classes accommodated learners who were not coping with grade-level work. In 2001, Education White Paper Six advocated for inclusive education. This policy promotes differentiated pedagogical practices to accommodate learners’ needs and minimize barriers to learning. However, research has shown that teachers do not have the required content and pedagogical knowledge to teach according to diverse learners’ needs. One of the reasons given is that the teacher education system does not prepare teachers adequately to teach in classrooms with diverse learners. This qualitative case study is underpinned by an interpretivist orientation as it seeks to ascertain how teachers understand and implement differentiated pedagogical tools in their practice. The research asks the question: How do Foundation Phase teachers understand and implement differentiated pedagogical tools? Seventy-six teachers enrolled for in-service Bachelor of Education (Foundation Phase) completed a questionnaire and three Foundation Phase teachers were observed and interviewed. Data gathered was analyzed using the Theory of Practice Architectures. The study found that the teachers recognized the importance of accommodating the different learners’ learning needs, however, they struggled to implement differentiated pedagogical practices in the classroom. , Thesis (MEd) -- Faculty of Education, Primary and Early Childhood Education, 2024
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Date Issued: 2024-10-11

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Gold mineralization at the Blue Rock Deposit, Gadzema Greenstone Belt: Implications on genesis and exploration for orogenic gold mineralization within Archaean Greenstone Belts of Zimbabwe

- Mavuwa, Tavashavira

Authors: Mavuwa, Tavashavira
Date: 2024-10-11
Subjects: Uncatalogued
Language: English
Type: Academic theses , Master's theses , text
Identifier: http://hdl.handle.net/10962/464944 , vital:76559
Description: The Blue Rock gold deposit was re-discovered by African Consolidated Resources (ACR) in 2007, over a defunct historical gold mine at Blue Rock, during a regional geochemical soil sampling program, within the Gadzema Greenstone Belt (GGB), in Central Zimbabwe. Most significant orogenic gold deposits within this belt occur as BIF- and quartz vein hosted orebodies. But unlike them, gold mineralization at Blue Rock is associated with felsite and quartz porphyry rocks. The GGB is a northern extension of the Midlands Greenstone Belt (MGB), where the common occurrence of mineralized felsites, in close association with major gold reefs within numerous gold mines is well documented. But no significant effort was directed towards their understanding or exploration in the past. They were never considered viable exploration targets for significant economic gold deposits, until recently. More attention was instead focused on high-grade BIF and quartz vein hosted gold, that dominate most orebodies exploited by numerous mines within the belt. At Blue Rock, ACR defined a significant JORC compliant felsite-hosted gold resource of close to a million ounces, which represents a brand new attractive open-pit mining opportunity. But the successful exploration for such type of mineralization, whose footprint is so different from the common ones previously mined within the GGB, no doubt, calls for a good understanding of this type of mineralization. Which makes felsite-hosted gold mineralization a prime candidate for research, based on a deposit whose discovery and development, I was fortunate to be part of during the past few years. In this contribution, the genesis, localization and economic significance of felsite-hosted gold mineralization is investigated, using the gold deposit at Blue Rock as a case study. The deposit could be understood best through the Mineral Systems Approach, used in this study to interrogate alternative ideas about its genesis using published information and deposit-scale exploratory data. Results from the synthesis of published information on the evolution of Archaean Greenstone Belts and genesis of their host orogenic gold deposits, are consistent with models that view orogenic terrains as having formed through horizontal accretion in modern-day like subduction-accretion systems, at continental margins, where orogenic gold deposition occurred via processes that could be explained quite simply, through a universal orogenic gold mineral systems model. According to this model, orogenic gold deposits are believed to have formed from near neutral fluids containing dissolved gold, generated directly from the devolatilization of a subducted oceanic slab together with its overlying gold-bearing sulphide-rich sedimentary package, or indirectly through fluid released from a mantle lithosphere that was originally metasomatized and fertilized during an earlier subduction event. The fluid migrated up-dip from the mantle to crustal levels, through advection or seismic pumping along lithosphere- to crustal-scale fault zones, to form orogenic gold deposits within lower order structures. If these models are all accurate, then the GGB formed through subduction-related east-directed horizontal accretion at the continental margins of the Sebakwe Proto-Craton (SPC), and the genesis of felsite-hosted gold mineralization at Blue Rock could be explained eloquently through a universal orogenic gold model, in which mantle derived auriferous fluids were localised within lower order structures associated with felsites during the late stages of terrain accretion. Evidence from surface mapping and 3D modelling of exploratory drilling data, conducted during this research, strongly support the argument that the felsite hosted gold mineralization at Blue Rock, is neither unique nor accidental. It is just but, a simple product of the conjunction of favourable geological factors, no different to those that birthed typical GGB orogenic gold mineralization hosted within sheared sulphidic BIFs and quartz vein reefs. They all share the same geodynamic setting, fertility, preservation and regional architectural factors reminiscent of accretionary orogenic settings, albeit with differences in local architecture, variably controlled by geochemical and rheological properties of the different local host rocks. At deposit scale, the felsites occur as small dykes and sills emplaced along pre-existing structural zones of weakness. Gold mineralization is structurally controlled and associated mostly with brittle-ductile shears. During deformation, rheological contrast played a significant role in the selective failure of the more competent felsite rocks, resulting in the creation of permeability channels that allowed fluid migration. The more brittle and competent felsites acted as rigid bodies, that localised strain along their contacts with the surrounding less competent ductile mafic schists which acted as a relatively less permeable fluid cap rock. The irregular felsite contact zones with surrounding mafic schist caused a significant variation in the orientation of local principal maximum stress relative to the internally imposed regional stress, causing anomalously low minimum stress zones at deposit scale. Gold deposition occurred within low minimum stress structural traps dominated by sheared felsite contacts and their fractured interiors as well as triple junctions formed by complex structural geometries created by multiple felsite intrusions. The felsite hosted gold at Blue Rock can therefore be recognized as an orogenic gold mineral system archetype, for which an occurrence model is proposed. Understanding this type of mineralization is key for developing a robust exploration strategy - one that could be applied in a predictive capacity in exploration, to locate new economic gold deposits especially within well-endowed mature orogenic terrains, where exploration risk could be minimized by leveraging on new forward-thinking initiatives like Artificial Intelligence (AI) to re-analyze data from previous mining and exploration, allowing for a faster route to a return on investment. In a world of diminishing natural resources, the potential for previously ignored gold mineralization like the one at Blue Rock, becomes very significant. The prophetic words of Foster (1984), writing in Gold ‘82, therefore remain true and relevant to our time, that; “…. the way ahead for successful gold exploration is to search for new deposits not commonly recognized – in auriferous muds, disseminations in carbonate rocks, porphyries, and in felsic intrusive and extrusive volcanics…”. , Thesis (MSc) -- Faculty of Science, Geology, 2024
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Date Issued: 2024-10-11

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Immobilisation of an Aspergillus niger derived endo-1,4-β-mannanase, Man26A, for the production of prebiotic mannooligosaccharides from soybean meal

- Anderson, Amy Sage

Authors: Anderson, Amy Sage
Date: 2024-10-11
Subjects: Aspergillus niger , Soybean meal , Mannosidases , Oligosaccharides , Immobilized microorganisms
Language: English
Type: Academic theses , Master's theses , text
Identifier: http://hdl.handle.net/10962/463897 , vital:76455
Description: This study investigated the potential for antibiotic alternatives in the form of prebiotics produced from the enzymatic breakdown of soybean meal (SBM). This study first investigated the immobilisation of an endo-1,4-β-mannanase derived from Aspergillus niger on glutaraldehyde-activated chitosan nanoparticles (CTS) and glutaraldehyde-activated chitosan-coated magnetic Fe3O4 nanoparticles (MAGS-CTS) - which could be effectively used to hydrolyse the galactomannan contained in SBM in a recyclable manner. The mannooligosaccharides (MOS) produced from the enzymatic digestion of SBM were then analysed for their prebiotic and antimicrobial capabilities to determine whether the strategy employed was capable of promoting and inhibiting probiotic and pathogenic growth, respectively. An Aspergillus niger endo-1,4-β-mannanase, Man26A, was confirmed by FTIR (Fourier-transform infrared spectroscopy) and XRD (X-ray powder diffraction) to be immobilised onto CTS and MAGS-CTS by covalent bonding. The immobilisation (%) and activity yields (%) were 81.14% and 35.45%, and 55.75% and 21.17%, respectively. The biochemical properties (pH and temperature optima, and temperature stability) of both the free CTS and MAGS-CTS immobilised Man26A enzymes were evaluated, with the pH optima shifting to a lower pH range after immobilisation (pH 2.0 – 3.0 vs. 5.0), while the temperature optima and stabilities remaining unchanged (at 60°C). CTS and free enzymes exhibited identical thermal stabilities, maintaining 100% activity for the first 6 hours at 55°C, while MAGS-CTS showed an immediate drop in relative activity after the first 30 minutes of incubation. Recyclability analysis revealed that CTS could be effectively reused for six reaction cycles, while the MAGS-CTS immobilised enzyme could only be used once. Both enzymes could be efficiently stored at 4ºC, showing a relative residual activity of 73% after 120 hours of storage. Substrate kinetic analysis showed that the free enzyme had the highest catalytic capabilities in hydrolysing locust bean gum (LBG), with the CTS immobilised enzyme was the most efficient in hydrolysing SBM, the insoluble, complex substrate. Sugar residues produced from the hydrolysis of LBG illustrated the effective breakdown of galactomannan to mannobiose (M2), mannotriose (M3), mannotetrose (M4), and mannohexose (M6). SBM-produced sugars analysed via TLC and HPLC indicated that the MOS residues were most probably glucose, galactose, and galactomannans (GM2 and GM3). The SBM-produced sugars were then evaluated for their prebiotic effect, illustrating their successful utilisation as a carbon source by probiotic bacteria; Streptococcus thermophilus, Bacillus subtilis and Lactobacillus bulgaricus. Evaluation of the antimicrobial activities of the SBM-produced sugars digested by probiotics suggested that their metabolites had the potential to be used as an antibiotic alternative. This study therefore illustrated that an endo-1,4-β-mannanase derived from Aspergillus niger could be immobilised successfully, for use in a recyclable reaction to produce MOS products. This study also described the successful use of SBM-sugars as a prebiotic, indicating a successful alternative to antibiotic growth promoters (AGP) by illustrating their positive effect on inhibiting growth of pathogenic bacterial species. , Thesis (MSc) -- Faculty of Science, Biochemistry, Microbiology & Bioinformatics, 2024
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Date Issued: 2024-10-11

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Integrating sustainability into strategic decision making in the South African automotive sector

- Makaudi, Tuelo Ivan

Authors: Makaudi, Tuelo Ivan
Date: 2024-10-11
Subjects: Uncatalogued
Language: English
Type: Academic theses , Master's theses , text
Identifier: http://hdl.handle.net/10962/461874 , vital:76247
Description: Sustainability has become a major topic for businesses, policy makers, government, and researchers. With the growing awareness of climate change, environmental and social problems, attention has turned to how businesses impact the environment, society, and economy. Sustainability, therefore, requires the integration of environmental and social issues into strategic decision making. Many organizations consider sustainability as an important issue for the business. However, some companies are struggling to combine business success and the success of other stakeholders, particularly those representing the interests of the environment and society. The purpose of this case study is to explore how sustainability is integrated into strategic decision making within some companies in the South African automotive industry. This study followed a qualitative approach, and semi-structured interviews were conducted with ten senior managers in the automotive sector in South Africa. The study used an inductive thematic analysis approach to analyse the data, and five main themes were generated: (1) Business profitability, (2) Organization culture, (3) Rationality, (4) Compliance, and (5) Corporate social responsibility (CSR). The findings of the study indicated that strategic decisions made considered business profitability first and foremost above environment and society. There is evidence that businesses engage in some sustainability activities, but this was related to the business objective to be profitable and to meet compliance requirements. The findings of the study also indicated that a rational decision-making approach was used predominantly, compared to intuitive and political approaches. This was due to the cautious approach of maintaining profit-making as a primary business objective. In terms of recommendations, this study recommends that automotive companies in South Africa integrate sustainability considerations into organizational/or business strategy to enable the industry to create shared value for the environment, society and economy. Integrating sustainability into business strategy will align business practices with sustainability goals and therefore allowing the automotive industry to have a positive impact in the society and environment which in turn will lead to improved financial performance. , Thesis (MBA) -- Faculty of Commerce, Rhodes Business School, 2024
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Date Issued: 2024-10-11

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