Research Articles (University of Pretoria)

Permanent URI for this collectionhttp://hdl.handle.net/2263/121

This collection offers open access to the full text of research articles published by staff, students and affiliates of the University of Pretoria. These items are identical in content to their published counterparts. It is linked to the Research Information System and complements the Annual Research Report.

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Does wind affect the orientation of vegetation stripes? A copula-based mixture model for axial and circular data
(Wiley, 2025-07) Mingione, Marco; Lagona, Francesco; Nagar, Priyanka; Von Holtzhausen, Francois Victor; Bekker, Andriette, 1958-; Schoombie, Janine; Le Roux, Peter Christiaan
Motivated by a case study of vegetation patterns, we introduce a mixture model with concomitant variables to examine the association between the orientation of vegetation stripes and wind direction. The proposal relies on a novel copula-based bivariate distribution for mixed axial and circular observations and provides a parsimonious and computationally tractable approach to examine the dependence of two environmental variables observed in a complex manifold. The findings suggest that dominant winds shape the orientation of vegetation stripes through a mechanism of neighboring plants providing wind shelter to downwind individuals.
Fertility care in low- and middle income countries : public sector access to medically assisted reproduction in South Africa : a case study
(Bioscientifica Ltd., 2025-07) Boshoff, Gerhardus Marthinus; Ombelet, Willem; Huyser, Carin; gerhard.boshoff@up.ac.za
In South Africa, approximately 10% of the calculated need for medically assisted reproduction is being met due to limited access and unequal availability of these services. To facilitate understanding of challenges associated with access to assisted reproduction, a retrospective case study spanning 6 years was performed at one public sector hospital in South Africa offering these services. Demographic profiles, including income, region of residency and access to medical insurance, of patients seeking assistance to become pregnant were investigated. Patients were categorised as those who underwent diagnostic investigations only vs those who returned for therapeutic procedures, and the difference in demographic profiles between the two groups was determined. This investigation showed that patients from the lower-income classification group, without medical insurance, tend to return for therapeutic procedures less often than those with a higher income and medical insurance, even though these low-income patients qualify for a therapeutic procedure subsidy. An inverse relationship existed where patient numbers decreased as their travel distance increased, but patients who were required to travel further for assisted reproductive therapy tended to return for these procedures more often than patients who resided closer to the medical facility. In conclusion, access to medically assisted reproduction facilities is critically undersupplied and limited in the region. In order to ease the travel distance of patients, alternative primary diagnostic routes with accessible clinics are needed. In addition, costs of therapeutic procedures in the public sector should be re-evaluated to be offered at affordable rates for marginalised patients.
Development of populational female thorax sizes and body habitus categories using computed tomography (CT) images
(Elsevier, 2025-08) Pape, R.; Xie, G.; Zheng, X.; Carstens, Ann; West, C.; Cowling, C.
INTRODUCTION: Positioning of the breast during mammography examination is critical to producing optimum quality images. However, the variation in female thorax and body habitus may affect mammography positioning for best image quality. This study aims to establish populational female thoracic (rib cage) sizes and quantify female body habitus categories. METHODS: A retrospective analysis of 347 female computed tomography (CT) chest axial scans was retrieved from an open access database to establish female rib cage sizes. Dimensions of the rib cage were measured digitally across six cross sections with six anterior rib landmark points and recorded in millimetres (mm). A Bayesian Network (BN) model was developed to establish the relationships of information extracted from the rib cage image data to quantify and categorise female body habitus. RESULTS: Female body habitus (thoracic size) were classified into three cohort categories: lean (20.5 %),norm (55.6 %) and curvaceous (23.9 %). The mean values (115–126 mm) and the corresponding 80 %prediction interval ranges for the healthy female rib cage size were obtained through the BN scenario analysis. CONCLUSION: The significance of this study is that it categorised 55.6 % of female thoracic sizes as being normal on a larger group of female population. This study contributed to a good understanding of the range of female body habitus (thoracic size) to improve positioning practice and maximize image quality. IMPLICATIONS FOR PRACTICE: This study used a BN model to establish a range of female thorax sizes using CT chest images to support improved positioning practices. These ranges of thorax sizes should be integrated as a body habitus criterion in the current image evaluation system to maximise image quality and subsequent breast cancer diagnosis.
Polyploid-diploid coexistence in the greater duckweed Spirodela polyrhiza
(Wiley, 2025) Mortier, Frederik; Van de Peer, Yves; Bonte, Dries
Polyploidy is widespread among plants and is often associated with stressful environments that can facilitate their establishment. Successful new polyploids must overcome competitive disadvantages against their progenitors or benefit from negative frequency-dependent growth. We tested the invasion of neotetraploid duckweed strains (Spirodela polyrhiza) into populations of their diploid progenitors in control and salt stress conditions in replicated microcosms. We also tested the reverse scenario: invasion of diploids in neotetraploid populations, to examine the impact of the initial tetraploid proportion. Tetraploid proportions declined in all tetraploid and diploid invasions, with different rates than predicted from only intrinsic growth rate differences. Salt stress affected the decline in a strain-specific manner. We found evidence for negative frequency-dependent growth that, nonetheless, was insufficient to overcome competitive disadvantages of neopolyploids. SYNTHESIS. Our findings demonstrate the crucial role of competition and frequency dependence on neopolyploid establishment. Therefore, we caution against inferring neopolyploid success based solely on intrinsic growth rates.
Developing online considerations for the IASWG standards on social work with groups : a tribute to Charles Garvin
(Routledge, 2025) Macgowan, Mark J.; Gardella, Lorrie Greenhouse; Simon, Shirley R.; Prinsloo, Reineth; Baar, Hilda; Seck, Mamadou; Astray, Andres Arias; Canizares, Catalina; Muskat, Barbara
In the spring of 2020, when the COVID-19 pandemic necessitated the remote delivery of health and human services, few social workers were prepared to facilitate online groups. Research on virtual group work was limited, and the IASWG Standards for Social Work Practice with Groups offered minimal guidance for online practice. Charles Garvin encouraged the International Association for Social Work with Groups (IASWG) to enhance the Standards with “online considerations” that would support effective group work in virtual environments. Serving as a mentor and active member of the Task Force on Online Considerations, Charles Garvin inspired a systematic, collaborative, and internationally inclusive process that exemplified principles of socially just research. This paper describes the research and development of the online considerations and the limitations and possibilities of defining international guidelines for social work with groups.
The role of communication between mammographers and patients in the Limpopo province of South Africa
(Elsevier, 2024-07) Chego, M. Katlego; Sethole, Khethiwe Margaret; Kekana, R.M. (Mable); Malherbe, Kathryn; kathryn.malherbe@up.ac.za
INTRODUCTION : Breast cancer affects women around the world. Communication is essential for managing and treating breast cancer, especially in the breast imaging department. By communicating effectively, mammographers can help to alleviate the fear and burden that breast cancer brings to the lives of affected women. In this study, we explored and described the role of communication between mammographers and post-mastectomy patients in the Limpopo province of South Africa. METHODS : This was a qualitative exploratory, descriptive study. Individual in-depth interviews were conducted with patients who underwent mastectomy as well as mammographers in selected healthcare institutions. Due to the different languages used in Limpopo, the researcher had this questionnaire for patients translated in Sepedi. Participants were purposively sampled. Data collection took approximately two months. Summative content analysis was used to analyse the data. RESULTS : Eleven mammographers and 36 patients were interviewed. Three themes emerged from the data collected. Mammographers highlighted the importance of being accommodative, supportive, and sympathetic towards patients. Mammographers made every effort to maintain a good communication path and understanding with their patients. The patients had high admiration for the work and support of mammographers and perceived mammographers as healthcare providers who were trustworthy and held them in high regard. CONCLUSION : Communication is key in ensuring cooperation between mammographers and patients. Additionally, the mode of communication, including the language should be considered. It is important that patients receive information in languages they are comfortable in. It will help patients understand the proceedings of the examination for which they have been booked for as well as the need for follow-up. Training related to communication for mammographers and possibly the addition of more South African languages as an extra course/module to allow communication with patients to be well carried out. IMPLICATIONS FOR PRACTICE : The study contributes to a growing body of knowledge within the training of mammographers as well as the implementation of role extension for mammographers.
Clinical utility of MODAPTS during work assessment : perceptions of South African occupational therapists
(Occupational Therapy Association of South Africa, 2024-04) Buys, Tania Lee; Harmse, Suzanne; Slawson, Caitlin Christina; Rapolai, Boitumelo Thamirah; Rapotu, Kwena Dorah; Furniss, Sian Gabrielle; Jordaan, Karma; tania.buys@up.ac.za
INTRODUCTION : Clinical utility is an important attribute in selecting an assessment tool. The study aimed to determine the perceptions of South African occupational therapists of the clinical utility of Modular Arrangement of Predetermined Time Standards (MODAPTS) work samples when assessing a client’s work ability. The research objectives were to determine whether MODAPTS is perceived to be credible, practical, useful, and easy to use. METHODOLOGY : A quantitative, cross-sectional, descriptive research design was used. Non-probability sampling with elements of voluntary response- and snowball sampling was used to recruit respondents. An electronic questionnaire was developed using Qualtrics, which was distributed electronically via the Occupational Therapy Association of South Africa, WhatsApp and Telegram. RESULTS : Data were based on 52 completed questionnaires, analysed through descriptive statistics. MODAPTS was perceived as practical, useful, credible, and asy to use in practice. Main barriers to the use of MODAPTS included the timeliness of developing work samples, lack of MODAPTS training, and having other more useful and reliable assessment tools. Experienced occupational therapists used MODAPTS more often than inexperienced occupational therapists. CONCLUSION : Clinical utility of work samples developed using MODAPTS has been confirmed. This supports the use of work samples developed using MODAPTS as part of work assessments as a cost-effective, practical tool. IMPLICATIONS FOR PRACTICE : • Development of contextually relevant work samples. • Use of MODAPTS work samples as an outcome measure during intervention. • Application during rehabilitation goal setting. • Cost effective application of MODAPTS work samples in a variety of settings.
Appropriateness of the standard manual wheelchair for occupational performance by wheelchair users in the Thulamela Municipality of the Vhembe District, Limpopo, South Africa
(Occupational Therapy Association of South Africa, 2024-08) Lister, Helga Elke; Nethathe, Khumbelo; Naidoo, Deshini; Govender, Pragashnie
BACKGROUND : Wheelchairs are an essential assistive device that assists with the facilitation of engagement in occupation especially those that require mobility. Anecdotally, there have been identified gaps in implementation of areas of wheelchair service delivery which included the referral, assessments, prescription, user and provider training, follow up and maintenance. Therefore, there was a need to investigate the appropriateness of the standard manual wheelchair for occupational performance in Thulamela Municipality Vhembe District, Limpopo. METHODS : An observational cross-sectional descriptive design using simple random sampling was used to select n=60 wheelchair users who were issued with standard manual wheelchairs between 2014 and 2018. The Wheelchair Outcome Measure was used to investigate the participants' level of satisfaction in engagement in ADL and IADL and the suitability of the wheelchair in terms of the user’s comfort and satisfaction with positioning and prevention of skin breakdown. Descriptive statistics were used to analyse the data. RESULTS : The wheelchair users viewed activity participation in the home as important and were generally satisfied with their standard manual wheelchairs while performing occupational activities at home and outside the home. A total of (n=46; 78%) of the participants felt comfortable in their wheelchair. CONCLUSIONS : Wheelchair prescription should take into consideration the occupational choices of the user. Further qualitative studies to explore the factors that determined the participants' choices for their activity participation goals should be undertaken.
Digital competencies among the greying population
(Library and Information Association of South Africa, 2024) Odu, Alice Olije; Van Wyk, Brenda; brenda.vanwyk@up.ac.za
Trends in emerging technologies, generative artificial intelligence and the use of ChatGPT and other AI tools necessitated certain skills for successful use. However, individuals, including greying, older adults find themselves at the periphery of the technological revolution. Their predicaments are caused by personal fears, unwillingness to use technologies, declining health conditions, disinterest, inability to transfer skills, competencies, and lack of knowledge and skills to use technologies. All these contribute to a gap referred to as the grey digital divide – a term referred to struggles older adults encounter in their digital technologies use. This inhibits access to vital information. Enhancing digital competence can support older adults to apply digital skills and knowledge in practical situations, which, in turn, can improve technology use and inclusiveness in the present technological era. This study used a scoping review where peer-reviewed articles were selected from databases. The literature revealed the need to build digital competencies among the greying population through sustainable digital literacy training, transferable skills, design of easy-to-use technologies suitable for older people with both cognitive and physical decline as well as policy for their digital inclusion.
The role of disruptive innovation in start-ups and transforming small business operations in the digital era
(South African Institute of Industrial Engineers, 2024-12-13) Lotz, S.J.; Verhage, B.; Masele, E.; Malanda, C.; Hassan, Ferdinand S.; Grobbelaar, Schalk; ferdinand.hassan@tuks.co.za
ENGLISH : In the digital era, start-ups benefit from expanded reach, faster scaling, and access to vast data sets, yet face heightened competition and the challenge of staying current with emerging innovations. Their role in the modern economy is amplified as they collaborate with incubators, investors, and academic institutions to foster innovation and growth. Agile development methods and disruptive innovation bolster their competitiveness against larger incumbents. Leveraging digital technologies and combining resources are further recognised as pivotal success factors driving disruptive innovations in start-ups.
The influence of project management maturity on perceived project success : a case study of the Lesotho water sector
(South African Institute of Industrial Engineers, 2024-11-29) Pretorius, Suzaan; Mohlapiso, Mpho P.M.; suzaan.pretorius@up.ac.za
ENGLISH : This study aims to determine the project management maturity level of four organisations in the Lesotho Water Sector. It assesses its influence on perceived project success by undertaking case studies in these organisations. It, therefore, contributes to the limited literature on project management maturity in the water sector in Africa. The results indicated that the average project management maturity was 2, with one organisation at a maturity level of 3. A total of 53% of executed projects were perceived as successful. The study found that high-maturity-level organisations tend to execute projects more successfully. Additional factors that may lead to project failure in this sector were identified.
Identifying the gap in assessing activities of daily living in resource-constrained rural settings : an integrative review of existing frameworks and instruments
(Occupational Therapy Association of South Africa, 2024-12) McAdam, Jennifer Claire; Casteleijn, Daleen; Franzsen, Denise
INTRODUCTION : The non-availability of indoor piped water and electricity results in alternate forms of personal care and domestic tasks in resource-constrained rural settings. This article examines the applicability of existing measures for the contextual assessment of basic and instrumental Activities of Daily Living (bADLs and iADLs) in these settings. METHOD : An integrative review guided by the approach of Lübbe et al. (2020) was conducted. Structured database searches of CINAHL, Scopus and Sabinet identified published articles which were subjected to eligibility criteria. Microsoft Excel was used to synthesize data RESULTS : The search strategy yielded 591 articles that met the inclusion criteria, from which 187 ADL instruments were identified. Three instruments suited to resource-constrained rural settings were identified. CONCLUSION : Occupational therapists should consider that existing ADL frameworks and instruments appear silent on the impact of limited access to household amenities in resource-constrained settings. This constitutes epistemic injustice as many rural households globally do not have potable water or adequate household energy supply. Global South occupational therapy curricula must include contextually relevant ADL frameworks and development of contextually relevant instruments should be prioritised. IMPLICATIONS FOR PRACTICE : The findings suggest that existing ADL instruments have limitations when utilised in the Global South, particularly in resource-constrained rural settings. As such, occupational therapists practicing in such settings need to interpret instrument scores with caution and apply contextual clinical reasoning in the best interests of service users. Furthermore, training institutions in the Global South must ensure that the limitations of existing ADL frameworks, models and instruments are made overt within curricula and that research efforts are directed towards the development of contextually relevant ADL instruments.
Designing coin-cell supercapacitors : combining graphene foam with metal oxide composite electrodes for improved energy storage performance
(Elsevier, 2025-03) Mirghni, Abdulmajid A.; Shuaibu, Abubakar Dahiru; Hardianto, Yuda Prima; AL-Qwairi, Fatima Omar; Hussain, Arshad; Shah, Syed Shaheen; Manyala, Ncholu I.; Aziz, Md. Abdul
Please read abstract in the article.
Modeling the output from a commercial chemical process using regression models from survival analysis
(Taylor and Francis, 2025) Coetzer, R.L.J.; De Waal, Daan; Smuts, M.; Visagie, I.J.H.
This article is concerned with the modeling of the gas output of a commercial chemical plant using the coal sources as predictor variables. We consider the use of two models to incorporate these predictors; the Cox proportional hazards and accelerated failure time regression models. These models are chosen for their simplicity and for the ease with which the effects of explanatory variables can be interpreted. The contribution of this article lies therein that these models are used in the current context for the first time. We show, using both graphical and formal hypothesis testing procedures that these models (with a Weibull baseline distribution) fit observed gas production data well. We provide a discussion of the interpretation of the estimated model parameters and we comment on how these estimates can be of substantial practical value. The large scale of production from the chemical plant in question ensures that potential cost savings and increases in production associated with more accurate models are of great practical importance.
Navigating health financing cliffs : a new era in global health
(Elsevier, 2025-05) Rasanathan, Kumanan; Beltran, Maylene M.; Biritwum-Nyarko, Alberta A.; Blecher, Mark S.; Dybul, Mark; Inoue, Hajime; Ohiri, Kelechi; Patcharanarumol, Walaiporn; Pillay, Yogan; Reddy, K. Srinath; Ren, Minghui; Cyrus Shroff, Zubin; Simons, Bright; Sparkes, Susan; Chalkidou, Kalipso
No abstract available.
Lessons for long-acting lenacapavir : catalysing equitable PrEP access in low-income and middle-income countries
(Elsevier, 2025) Lynch, Sharonann; Cohen, Rachel M.; Kavanagh, Matthew; Sharma, Agrata; Raphael, Yvette; Pillay, Yogan; Bekker, Linda-Gail
Despite substantial advances in biomedical HIV prevention, including long-acting injectable pre-exposure prophylaxis (PrEP) options such as cabotegravir, barriers to widespread adoption and scale-up persist in low-income and middle-income countries. Long-acting injectable lenacapavir is a potentially transformative HIV prevention tool, providing an unprecedented opportunity to accelerate progress. However, the global HIV response is under threat like never before, with drastic funding cuts undermining the gains of the past 25 years. The challenges of introducing and scaling up long-acting lenacapavir and other PrEP innovations are numerous. Without deliberate policy, programmatic, and financing interventions, new prevention technologies risk following slow adoption patterns of previous innovations, weakening a needed transformation of the HIV response. Drawing on lessons from the scale-up of antiretroviral therapy, and experience with previous biomedical prevention tools, a new ten-point framework should be adopted to accelerate individual and epidemiological impact—even at this time of extraordinary uncertainty.
Navigating market turbulence : a configurational perspective of ambidextrous innovation in strengthening organizational resilience in sub- Saharan Africa
(NISC Pty (Ltd) and Informa UK Limited, trading as Taylor & Francis Group, 2025-07) Okrah, Andrews Osei; Boso, Nathaniel; Mensah, Henry Kofi
This study investigates the relationship between ambidextrous innovation capabilities and organizational resilience in Micro, Small, and Medium-Sized Enterprises (MSMEs) in Ghana, with a focus on the moderating role of external market turbulence. Drawing on data from 285 MSMEs, the research adopts a quantitative approach, employing confirmatory factor analysis and Hayes PROCESS Macro to test the hypotheses. The findings reveal that ambidextrous innovation – comprising both exploitative and exploratory dimensions – positively influences organizational resilience, enabling firms to adapt to challenges and capitalize on opportunities. Additionally, the study highlights the significant moderating effect of external market turbulence, wherein higher turbulence levels strengthen the positive impact of ambidextrous innovation on resilience. These results contribute to the literature on innovation and resilience by providing empirical evidence from the sub-Saharan African context, particularly in MSMEs operating in volatile markets. Theoretical and practical implications are discussed, with recommendations for MSMEs to foster balanced innovation capabilities to enhance their resilience in uncertain environments. The study also identifies areas for future research, including exploring additional contextual variables and expanding similar studies to other regions.
Navigating the waves of change and ripples of challenges in the water supply chain sector
(South African Institute of Industrial Engineers, 2024-11-29) Naidoo, Kelsi; Van der Lingen, Elma
ENGLISH : The Fourth Industrial Revolution (4IR) has ushered in a transformative era for industries worldwide, including the water sector. This paper investigates the difficulties that are encountered and the changes that are required in water sector supply chain management amid the 4IR. A comprehensive analysis of scholarly articles, research papers, and industry reports provides insights into the evolving dynamics of water supply chains. The review identifies challenges such as data integration complexities, cybersecurity vulnerabilities, budget constraints, regulatory intricacies, skills gaps, environmental sustainability concerns, infrastructure compatibility issues, data privacy dilemmas, resource limitations, socio-political factors, and geographical disparities. These are critically examined within their contextual frameworks, highlighting their significance for the water sector. This paper is valuable for researchers, policymakers, water utility professionals, and stakeholders seeking a comprehensive understanding of water sector supply chain management’s intricate challenges and transformative changes during the 4IR. This paper could also assist in illuminating water-related problems and solutions.
Developing an industrial engineering capabilities framework for the adoption of engineered wood products in the South African construction industry
(South African Institute of Industrial Engineers, 2024-11-29) Hassan, Ferdinand S.; Grobbelaar, Schalk
ENGLISH : The construction industry is embracing sustainable practices to combat environmental degradation and climate change, and engineered wood products (EWPs) offer promise as structural materials for sustainable infrastructure. Despite the benefits of EWPs, challenges such as supply chain integration and market acceptance have limited their use. This paper explores how industrial engineering could facilitate the adoption of EWPs in the South African construction industry, and provides a framework for developing critical industrial engineering capabilities that the South African timber construction sector should possess to integrate EWPs efficiently into construction projects. We used a comprehensive literature review and a curriculum analysis to achieve the study’s objectives. By drawing upon these capabilities, the study identified where industrial engineering as an expertise could drive innovation adoption.
Agile : advantages, disadvantages, enablers, and barriers
(South African Institute of Industrial Engineers, 2024-12-13) Lutwama, P.; Dlulane, M.; Pillay, T.; Hassan, F.S.; Grobbelaar, Schalk; ferdinand.hassan@tuks.co.za
ENGLISH : This scoping review provides an expanded view of the Agile methodology in the software industry - an iterative, incremental project management framework that is renowned for its use in software development. Research questions covering the advantages, disadvantages, enablers, and barriers to Agile were formulated to analyse accepted research papers from 2019 to 2023. Notable overlapping findings were found in the 25 studies that were included. The results revealed that human factors such as communication, conflict resolution, and understanding Agile are essential to the successful implementation of Agile software development.

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