UWCScholar
This repository serves as a digital archive for the preservation of research outputs from the University of the Western Cape.
Communities in UWCScholar
Select a community to browse its collections.
Recent Submissions
Flexible feature engineering using a network flow approach
(Universty of the Western Cape, 2024) Bodenstein, Gerhardus; Blignaut, Renette
Feature engineering, a critical part of the data preparation and exploration phase in predictive modelling, involves transforming predictor variables to enhance interpretability and better understand their relationship with the response variable. In some cases, it also offers automatic handling of outliers and missing values. Many machine learning and data mining techniques perform better with discretised continuous variables or clustered levels of categorical variables, making feature engineering essential for improving the accuracy and robustness of predictive models. Furthermore, the feature engineering process often needs to incorporate business, operational, or best-practice constraints applicable to the final transformed predictor variables or newly created features. This thesis addresses two significant challenges in feature engineering. The first is the supervised discretisation of continuous predictors, which involves partitioning a predictor's domain into disjoint intervals while preserving a specified trend in the relationship with the response variable and adhering to side constraints.
Genome-wide characterization of DREB transcription factors in Medicago truncatula: Insights into their roles in development and abiotic stress response
(Elsevier Inc, 2025) Ndiko, Ludidi; Haddoudi, Loua; Ayadi, Mariem
Dehydration-responsive-element binding (DREB) proteins play a crucial role in drought, salt, and environmental stress tolerance. In this study, we identified and annotated fifty-four DREB genes from the Medicago truncatula genome. These genes were analyzed at the molecular level, focusing on gene classification, genomic organization, phylogeny, synteny, structural features, and expression profiles. Phylogenetic analysis revealed that MtDREB proteins are categorized into six subgroups (A1–A6), with highly conserved motif compositions among them. Expression profiling showed that MtDREB genes are differentially expressed in various plant organs and under abiotic stresses (cold, salinity, and dehydration), with 30 % exhibiting high expression during flowering and development. Data from RNA-seq and microarrays demonstrated that 76 % of MtDREB genes are differentially expressed under at least one stress condition, indicating their involvement in various signaling pathways activated by abiotic stresses. Notably, MtDREB05, primarily induced under osmotic stress, appears to be a promising candidate for improving abiotic stress tolerance. These findings will enhance our understanding of the DREB family and aid in functional validation of DREBgenes in M. truncatula and related forage species.
BRAF p.V600E-negative langerhans cell histiocytosis associated with a periapical cyst: a case presentation with broad review of the differential diagnosis and disease pathophysiology
(Springer, 2025) Odendaal, Anneze; van Rensburg, Leon Janse; Afrogheh, Amir H
Background: Langerhans cell histiocytosis (LCH) rarely presents in the oral and maxillofacial region, and while isolated and small collections of Langerhans-type cells have been found in periapical cysts, there have been no reported cases of LCH arising in periapical cysts. Methods: A 58-year-old female presented with isolated erythematous dry skin lesions and a radiolucent lesion of the anterior maxilla. Microscopic examination of the enucleation specimen revealed a periapical cyst with large collections of atypical cells with grooved folded nuclei with eosinophils consistent with LCH. Immunohistochemistry (IHC) was performed to confirm the diagnosis. BRAF mutation status was evaluated with the BRAF p. V600E antibody and the automated real-time PCR-based Idylla™ assay, capable of qualitative detection of 5 mutations in codon 600 of the BRAF gene. Results: The LCH cells were positive for S100, CD1a, and Langerin (CD 207) and negative for BRAF p. V600E mutations. Ki-67 was 45%. Conclusion: The association of LCH with a periapical cyst could be explained by the active surveillance and migration of neoplastic Langerhans-type cells in blood to the site of apical chronic inflammation, in a patient with LCH. Careful attention to morphologic features in conjunction with Langerin IHC, helps exclude other closely-related dendritic tumours. BRAF p. V600E testing, ideally with real-time PCR assays, can help identify patients who may benefit from BRAF inhibitor therapies. New generations of sequencing that cover a large panel of genetic alterations beyond the frequent BRAF p. V600E mutations (e.g. rare in-frame BRAF deletions), could provide valuable information about the extent, prognosis and treatment of LCH patients. © The Author(s) 2025.
The concept of tolerance in the chishtī sūfī order
(Universty of the Western Cape, 2024) Kagee, Mohammed Luqmaan; Saidi, Mustapha
The purpose of this thesis is to provide a critical analysis of the concept of tolerance (al-tasāmuḥ) in the Chishtī Ṣūfī Order, one of the main Ṣūfī orders within Islam. The notion of tolerance implies various connotations that are widely found. These inferences include love, mercy, compassion, co-existence, and openness. All Ṣūfī philosophers have discussed these principles in their books. In this study, I aim to clarify the meaning of the term ‘tolerance’, as well as to elucidate on the connotations implied by tolerance in the Chishtī Order. Special focus will be given in this research to certain books, teachings, didactic poems and utterances (malfuẓāt) of some of the most authoritative and prominent Chishtī Ṣūfī personalities, who exercised tolerance in their practices. This study will, more specifically, provide an exposition on Chishtī pioneers, who are synonymous to the expansion of Islam in South Africa. I will offer a comparison on the diverse views regarding tolerance and identify the dominant ideological trends in the available literature.
System design implications of online surveillance in learning platforms: a data management perspective
(University of the Western Cape, 2024) Sterras, Raihaan; Breytenbach, Johan
Purpose: In the wake of the COVID-19 pandemic and the resultant uncritical mass uptake of online and blended learning approaches to replace face-to-face lectures, learning systems/platform designers are re-evaluating the negative effects of online learning systems. The purpose of the study is to systematically identify and review all relevant articles over the past two decades that discuss the negative effects of online learning systems and to provide key data management considerations. These key considerations identify important data management principles that should be considered during the design of online learning platforms to prevent the misuse of online data.
Methodology/design: The online education system-surveillance debate captured some interest in the previous decade and again in recent years leading up to 2021. Using a systematic literature review approach, we trace key articles in the online surveillance debate over the last two decades. From these articles, we extract system design considerations using the data management lens to inform the design of online learning systems and to prevent misuse of data within the online surveillance paradigm. Practical implications: This research has implications for system designers who develop online education platforms. This qualitative study gathers articles from the past two decades to identify key principles that could assist in developing a future system design framework for online educational platforms. These key principles can enhance the online data security of the educational institution.
Originality/value: This paper looks to identify the key principles from a data management perspective that need to be considered when developing online educational platforms. The systemic view of these principles will provide system designers with a minimal framework that identifies considerations when developing an online education platform, thereby enhancing the online data management of individuals (students and staff).
Data Collection: We used the systematic four-phase approach to collect data. The approach uses a systematic approach to identify themes, organise, and offer insight into the meaning of themes.
Finding/Recommendation: The study's findings identified six key design principles that should be taken into account when designing any LMS system within the HEI. These principles include (1) safety, which involves creating safe online collaboration spaces; (2) consent; (3) no surveillance and denormalisation of surveillance; (4) regulatory principles; (5) learning analytics paradox; and (6) preventing behavioural manipulation.