Faculty of Science, Engineering and Agriculture

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Open Access
3D Cranial Morphometry, Sensory Ecology and Climate Change in African Rodents
(2019-05-15) Nengovhela, Aluwani; Taylor,, Peter; Braga, Jose
The order Rodentia is the most speciose group of mammals with muroids being the most diverse superfamily. Since they are represented in arboreal, semiaquatic, subterranean and terrestrial niches, rodents may exhibit morphological traits reflecting their adaptations to such diverse environments. This thesis focuses on the morphology of the endocranium, auditory bulla and cochlea in three tribes (Otomyini, Taterillini and Gerbillini) representing 10 species of African rodents, concentrating on their variability, function and adaptability, using micro-CT imaging and 3D shape comparative methods. Additionally, variations in cranial size were also studied in respective of global warming and climatic variables. Morphological changes/variations are a result of environmental change, therefore each chapter in this study details the effect of environmental change (in space and time) on different morphological traits i.e. general cranial size (chapter 2), cochlea and auditory bulla (chapter 3) and endocranial size and shape (chapter 4). With chapter 2 dealing specifically with climate change in its strict sense and the remaining two chapters looking at different environmental gradients. Chapter 2 tests the applicability of the “third universal response to warming” (i.e. declining body size) and the Resource Rule in two murid subfamilies, Murinae and Gerbillinae. The study shows that the third response is not as universal as only one species conformed to this response. Further, food availability (Resource Rule) was shown to be the more important factor correlated with body size variations in rodent species than Bergmann’s Rule. Chapter 3 looks at the auditory bulla and cochlea, the morphological traits that play a role in hearing capabilities of rodents. I found, with some exceptions, that bulla and cochlea modifications between species could be explained by environment, phylogeny and/or allometry. In addition, I concluded that true desert adapted laminate-toothed rats and gerbils use both bulla and associated cochlea hypertrophy. Chapter 4 shows larger brain size in Taterillini and two species of Otomyini, with life histories and environment being the most probably factors responsible for xiv this. Using a novel method of diffeomorphism (deformation models), there was more variation in endocranial morphology between the gerbils and laminate-toothed rats than within them with olfactory bulb, paraflocculi, and posterior ventral cortex showing the most variability. Overall, this thesis shows that variations in the morphological traits studied are strongly influenced by the environment and function.
Embargo
A Comparative Study on the Efficacy of Modified Clay Soil for the Decolouration of Acidic and Basic Textile Dyes: A Case Study
(2025-09-05) Chauke, Livingstone; Gumbo, J. R.; Ngulube, T.
Dyes play a crucial role in the production of various products, including paper, plastics, and leather. However, their release into the environment leads to pollution and poses health risks to both humans and animals. Therefore, it is essential to treat dye-containing effluents before they are discharged into the environment. This study employed a cost-effective method to remove dyes from wastewater by utilizing natural clay as an adsorbent. The efficacy of Mn²⁺/Al³⁺ oxide-modified Mukondeni black clay soil (smectite) in removing acidic (Methyl Orange, MO) and basic (Crystal Violet, CV) textile dyes was evaluated. A 1:3 modified smectite ratio was identified as the most effective adsorbent. Characterization using X-ray Fluorescence (XRF), Brunauer-Emmet-Teller (BET), X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Energy Dispersive Spectroscopy (EDS), Fourier Transform Infrared (FTIR), and Point of Zero Charge (PZC) revealed that Modified-SMT contained 18.42% Al₂O₃ and 61.08% SiO₂, had a surface area of 35.30 m²/g, and featured functional groups such as C–O, C–O–C, and O–H, with a PZC at pH 4.30. Maximum dye removal efficiencies were recorded at 91.95% for MO after 90 min under the conditions (initial dye concentration = 20 mg/L, temperature = 30 °C, contact time = 90 minutes, shaking speed = 250 rpm, solution volume = 30 mL, and an adsorbent mass = 2 g). For CV, an efficiency of 96.35% was achieved after 30 minutes under conditions (initial dye concentration = 20 mg/L, temperature = 30 °C, contact time = 30 minutes, shaking speed = 250 rpm, solution volume = 30 mL, and an adsorbent mass = 0.1 g). Adsorption isotherm analysis indicated that MO followed a multilayer mechanism on heterogeneous surfaces (Freundlich model), while CV exhibited monolayer adsorption on homogeneous surfaces (Langmuir model). Kinetic studies confirmed pseudo-second-order behaviour. Thermodynamic parameters Δ𝐻 = - 47.72 KJ/mol and Δ𝑆 = -0.17 J/mol/K showed that MO adsorption was non-spontaneous and exothermic (ΔG = 12. 64 KJ/mol for 80 °C), whereas Δ𝐻 = 22.64 KJ/mol and Δ𝑆 = 0.09 J/mol/K for CV adsorption was spontaneous and endothermic (ΔG = -9.55 KJ/mol for 80 °C). The adsorbent retained its efficiency over four regeneration cycles, demonstrating its suitability as a sustainable and effective solution for dye removal in wastewater treatment. It can be concluded that Mn²⁺/Al³⁺ oxide-modified Mukondeni black clay soil (smectite) can remove both MO and CV dye from aqueous solution.
Embargo
A learning domain-based training approach for smallholder irrigated maize farming in Mashonaland Central Province of Zimbabwe
(2025-05-16) Binala, Livinia; Francis, J.; Mupetesi, T.
The study was carried out to investigate the effectiveness of training approaches for smallholder irrigated maize farmers in Zimbabwe, particularly their crucial role in national food security and rural livelihoods. Despite irrigation's potential to boost productivity of maize, many farmers encountered challenges in adopting improved practices partly due to inadequate training methods. Thus, the study sought to evaluate current training frameworks and propose a comprehensive model integrating Bloom's taxonomy of learning domains to enhance knowledge acquisition and practical skills among farmers. The objectives of the study were 1) to identify the key learning domains for effective use of irrigation technologies in smallholder maize farming in Mashonaland Central Province 2) to propose a training approach that is tailored to the identified learning domains and the specific needs and constraints of smallholder farmers in Mashonaland Central; 3) to evaluate the effectiveness of the developed training approach on the productivity and income of smallholder maize farmers in Mashonaland Central Province; and 4) to assess the effectiveness of the developed training approach in improving the knowledge and skills of smallholder farmers in the use of irrigation technologies for maize farming. Three irrigation schemes that focused on maize production and located in two natural regions, that is, II and IV within Mashonaland Central Province were purposively selected. Proximity to the Harare, the capital city or extent of the scheme’s rurality was considered. The census method of data collection was applied. All the 472 farmers involved in irrigation in the three schemes were earmarked for the questionnaire-based survey. Employing a mixed-methods approach, the study combined quantitative surveys and qualitative interviews with farmers and agricultural extension officers across the three irrigation schemes. Key findings indicated that Farmer Field Schools (FFS) significantly outperformed traditional Master Farmer Training (MFT) in promoting effective learning and adoption of sustainable practices (P < 0.05). The study underscored the importance of participatory training methods, which resonate more effectively with farmers' needs and educational backgrounds. Using the results of the study, a framework that includes the following as the key components was proposed: a) Incorporation of cognitive, affective, and psychomotor learning domains b) Prioritization of hands-on training with visual aids c) Promotion of sustainable farming practices d) Strengthening of farmer-extension linkages e) Investment in teaching materials and monitoring mechanisms This study advocated for a paradigm shift in agricultural training methodologies. Adopting the recommended framework would enable policymakers and practitioners to significantly enhance the productivity and livelihoods of smallholder maize farmers, thereby contributing to improved food security. Furthermore, the study highlighted the need for deploying participatory and practical training, addressing key skills gaps, in addition to developing robust farmer-extension relationships to achieve these goals. Integration of Bloom's learning domains into farmer training curricula is a strategic roadmap for designing more effective and impactful training of smallholder irrigated maize farmers.
Open Access
A metagenomic snapshot of selected wastewater treatment plants in Vhembe Region, Limpopo, South Africa: Investigating the resistome
(2024-09-06) Jacobs, Damien; Potgieter, N.; Traore, A. N.
Background: Water is crucial for human life. Rural communities often rely on natural water sources which may become polluted by wastewater due to various activities such as domestic use and agriculture. Antibiotic resistance genes (ARGs) may be transferred from wastewater to the environment and pose a global challenge they affect both human and animal-related sectors. Studying antibiotic resistance in wastewater treatment plants within Vhembe offers a representation of antibiotic resistance genes from entire communities. Knowledge of antibiotic resistance circulating in Vhembe has been sparsely studied. Metagenomics approaches allow for a broad overview of the resistome and the bacterial communities within environmental samples. Aim: To perform wastewater surveillance of antibiotic resistance genes and associated bacteria within Vhembe, Limpopo, South Africa, using a metagenomics approach. Method: A total of 32 sample duplicates were collected from the influents (n=18) and the effluents (n = 14) from nine wastewater treatment plants (WWTPs) around the Vhembe region, Limpopo, South Africa. One hundred milliliter was filtered using sterile cotton gauze and Wattman filter paper to remove debris and membrane filtered through 0.22um membrane filters to capture the bacteria within each sample. DNA was extracted directly from the 0.22 μm filters using a DNA miniprep kit. DNA was quantified using a spectrophotometer. Shotgun 18 metagenomic sequencing was performed on DNA extracts. Open-source bioinformatics pipelines were used to process and analyze raw sequence data, uncovering information of the bacterial community composition and associated ARGs in wastewater. Results: Site observations reveal animal and human activities within and near the sites. ARG analysis revealed an overall number 0f 220 ARGs detected across the WWTPs. Thirty-six genes were common to influent samples and 16 in within effluent samples, encoding predominantly against macrolides, sulfonamides and tetracyclines, beta-lactamases, and aminoglycosides. Some unique ARGS were detected at sites near South African borders. Bacterial Diversity showed the predominance of some genera, such as Arcobacter, Aeromonas, Pseudomonas and Acinetobacter. Pathogens were predominantly enteric and pulmonary, with some being linked to animals in past studies. A notable increase in some members of Mycobactericeae, among other bacteria, was noted in effluents.
Embargo
A Multi-level Model for a Vector-Borne Organ to Tissue life Cycle Dynamics
(2025-09-05) Mahada, Awelani Sydney; Netshikweta, R.; Garira, W.
Introduction: Malaria is among the World’s most lethal infectious disease. It is caused by a parasitic pathogen transmitted by the Anopheles mosquito, which inoculates sporozoites into the human host during a blood meal. The population dynamics of malaria are well-known for their complexity, stemming not only from the parasite’s lifecycle, which involves two hosts (humans and mosquitoes)but also from the intricate replication and transmission cycles across different levels of the infectious disease system organization. Like other infectious disease systems, malaria infections inherit multilevel and multiscale systems, which pose significant challenges to efforts aimed at eliminating and ultimately eradicating the infection in a malaria-endemic population. Methodology Mathematical modeling in the study of complex system has proven to be an invaluable tool for understanding and predicting the behaviour and dynamics of a complex system within the domain of complexity science. Thus, in this study, we propose a multiscale modelling framework that captures the dynamics of malaria across three organizational levels within infectious disease systems implicated in the spread of malaria in a community. We begin by formulating a mathematical model to describe the development and progression of malaria parasites within the liver and tissue(blood) stages of an infected human host. This is followed by the formulation of a multiscale model that integrates both the inside(i.e.,the organ-tissue level)host and the outside (i.e., the host level) host malaria dynamics. Results Mathematical analysis for both the malaria models presented in this study was carried out and proved that all the models are mathematically and epidemiologically well-posed. We also compute the basic reproduction number R0 for both models and use the R0 to determine the local and global stability of the disease-free equilibriumas well as the local stability of endemic equilibrium of both models, respectively. We demonstrate that if R0 < 1, then the diseasefree equilibrium pointy of both models is locally and globally asymptotically stable, respevctively. However, if R0 > 1 the endemic equilibrium point of both models is locally asymptotically stable. The numerical results for both the models have demonstrated that the goal of intervention during malaria infection should be to reduce the rates at which merozoites and gametocytes invade healthy liver tissue as well as the blood cells. Hence it is recommended that interventions during malaria infection be directed on reducing the pace at which merozoites infect healthy blood cells and the density of merozoites in circulation. Conclusion The study presents a method that incoporates the complexity of malaria pathogens which is significant not only for malaria treatment but also for other vector-borne disease system control treatment strategies.
Embargo
A private sector-inclusive governance framework for local economic development in rural areas of Limpopo Province in South Africa
(2025-09-05) Jeleni, Albert; Francis, J.; Kilonzo. B.; Chakwizira, J.
Local Economic Development (LED) remains globally recognized as a critical instrument for building inclusive and globally competitive local economies by stimulating job creation, diversifying local economies, and broadening municipal revenue bases. The concept of LED was born out of the realisation that while economic development intent and principles (that of constructing and realising a sustainable future) are universal, the outcomes are bounded by national policies and priorities and are determined by specific local societal, environmental, and business characteristics and interactions, which, if not balanced properly, can distort/contradict economic development intent and principles, leading to inefficient economic development. LED therefore seeks to address these distortions by aligning universal principles with localised realities, while maintaining adherence to free-market economic principles and ensuring that local development interventions do not unduly disrupt market dynamics. Its effectiveness hinges on capturing grassroots knowledge—honouring local expertise and traditions—and innovating on these insights to realign local economic outcomes and maximise wellbeing in line with national imperatives and global agendas. However, in South Africa, particularly in the rural context of the Limpopo Province, LED implementation continues to face significant challenges. These are primarily rooted in systemic governance shortcomings, the exclusion of private sector participation, and the enduring legacy of state-centric approaches that have perpetuated poverty, high unemployment, and spatial inequalities stemming from apartheid-era development patterns. Rural Limpopo reflects these conditions acutely, with unemployment exceeding 45%, inequality exceeding Gini coefficient of 0.59, poverty levels surpassing 67%, less than 8% of municipalities received clean audits, and municipalities being heavily reliant on subsidies & bailouts, further exacerbated by inadequate infrastructure and weak institutional capacity. To counter these challenges, South Africa has consistently looked to Local Economic Development (LED) as a solution and has recently developed an innovation-driven National Framework for LED 2018–2028. The 2018–2028 LED Framework is robust in principle, anchored on forward-looking pillars designed to spur innovation, inclusivity, and institutional resilience at the municipal level. Yet, in practice, few municipalities have successfully implemented it, particularly the enabling pillars. This disconnect stems from weak institutional capacity, poor integration into municipal planning, and the low prioritisation of LED by local governments. Crucially, there has also been significant under-inclusion of the private sector, despite its vital role in driving innovation, investment, and job creation. Without active collaboration with private businesses—especially SMMEs—municipalities struggle to leverage innovation-driven strategies effectively, leaving the framework’s transformative potential largely untapped. Moreover, failure to implement the LED framework hinders the localisation of the Sustainable Development Goals (SDGs), weakening multi-stakeholder partnerships—including government, civil society, and the private sector—that are essential for achieving the SDGs. To investigate these challenges, this study employed a mixed-methods research approach, integrating quantitative surveys and qualitative focus group discussions conducted across all five districts of Limpopo Province to develop a private sector-inclusive governance framework. The research identified three critical governance failures that inhibit LED outcomes: (i) persistent ambiguity regarding the roles and responsibilities of key ecosystem actors—government, private sector, and civil society; (ii) misalignment between national strategic frameworks and local operational realities; and (iii) epistemic disparities that result in the underutilisation of private sector expertise, capital, and entrepreneurial capacity. These governance failures are further compounded by a fundamental conceptual ambiguity surrounding LED itself. Within the South African context, LED is frequently conflated with adjacent paradigms such as socio-economic development, socio-political development, social entrepreneurship, and entrepreneurship development. This lack of definitional clarity contributes to fragmented interventions, duplication of efforts, and missed opportunities for integrated and inclusive local development. As a result, LED implementation remains inconsistent, often disconnected from territorial needs, and inadequately aligned with the potential contributions of the private sector. To redress these deficiencies, the study developed a Private Sector-Inclusive Governance Framework for LED, structured around three interrelated platforms. The first platform—the Multi-Stakeholder Platform ("WHO")—formalizes the roles of stakeholders, institutionalizes collaboration within economic principles, and establishes shared decision-making structures. The second platform—allows setting of objectives and the respective Monitoring, Evaluation, and Adaptive Capacity Platform ("WHY")—anchors LED processes in objective-based continuous learning, performance tracking, and adaptive management, aligning with the six pillars of the South Africa’s National LED Framework (2018–2028) and the global Sustainable Development Goals (SDGs). The third platform—the Standardization and Implementation Platform ("HOW")— allows for the selection of appropriate LED elements, it applies a project management-oriented approach to guide LED operationalization, including value chain optimization across all sectors and industries. Crucially, the framework asserts that the actors (government, private sector and civil society) must operate within the principles of a free-market economy, wherein the state plays an enabling rather than interventionist role. Accordingly, local governments are encouraged to institutionalise mechanisms that promote inclusive Public-Private Partnerships (PPPs), leverage Corporate Social Responsibility (CSR) initiatives, and invest in Public Goods Services (PGS) to stimulate sustainable economic growth. The framework reconceptualises LED governance not as a substitute for market processes but as a catalyst. Free-market principles—fair competition, limited distortion, and entrepreneurial innovation—are foundational to the proposed model. The framework mandates the use of market diagnostics and cost-benefit analysis to determine the most efficient delivery mechanism—prioritising private sector-driven hybrid approach where viable, and public provision only where market failure exists. Wherefore, municipalities are repositioned as enablers of competitive innovative ecosystems, investing in public goods and unlocking market participation through regulatory clarity, digital access, and transparent procurement. This approach discourages the state from running parallel or competing programmes that undermine private sector participation, and instead calls for a governance model that incentivises market-based solutions and fosters long-term enterprise development. The proposed framework allows stakeholders to systematically select development objectives (the WHY) from multiple typologies (including innovation-driven, infrastructure-led, social cohesion, and sustainability objectives), choose the leadership style (the WHO) from among state-led, private sector-led, private sector-driven hybrid, state-driven hybrid, and civil society-driven hybrid models, and implement LED through specific elements (the HOW) such as anchors, intermediaries, infrastructure, governance networks, and citizen engagement Empirical findings demonstrate that only 35% of rural municipalities currently engage private sector actors meaningfully in LED governance, despite the private sector’s essential role in mobilizing financial resources, driving innovation, and facilitating scalable development. This study proposes an innovation-driven, private sector-driven hybrid approach, and knowledge-based governance framework for Local Economic Development (LED) in rural Limpopo, South Africa. Engaging 366 respondents—including 47.5% from the private sector and over 70% with post-school qualifications—it revealed that despite 92.4% awareness of municipal institutions, only 37.9% participated in LED processes, underscoring the limited leadership role of local businesses. A review of 27 global LED frameworks showed universal emphasis on sustainability and equity, but fewer than 50% integrate innovation and adaptive governance elements. The study further illuminates recurring local impediments included corruption (14.8%), funding shortages (11%), and skills gaps (12.3%). Sectors like mining and agriculture exhibited strong value-chain comprehension, whereas digital integration and advanced manufacturing capabilities remain weak. Despite 60.8% of respondents recognizing corporate support for SMMEs, only 24.1% reported tangible engagement, indicating missed opportunities for public–private synergy. These findings carry significant implications for Limpopo and broader South African LED strategies. An innovation-driven LED model would leverage private sector dynamism and foster knowledge-based value chains, aligning with Limpopo’s development objectives to become more industrialised, labour-absorbing, and globally integrated. To unlock this potential, LED policy must embed mechanisms for strengthened collaborative governance, streamlined funding, targeted capacity-building, and proactive private sector participation. Such a transformation could drive inclusive growth, reduce rural inequalities, and align with national priorities articulated in South Africa’s LED Framework and Limpopo Development Plan. The proposed framework conceptualises LED as a multi-objective optimisation problem, where local maxima are identified, filtered through Pareto dominance, and integrated into a global Pareto front—thus transforming local successes into globally relevant solutions. Accordingly, it incorporates a mathematical modelling component designed to operationalise this optimisation process and guide decision-making. Essentially, the framework proposes that LED strategy design should be systematic and iterative—a process optimization exercise that begins by selecting desired outcomes (e.g., innovation, jobs, sustainability) in the “WHY” Platform. From there, leadership style (state-led, private-led, community-led, or hybrid) is chosen in the “WHO” platform, and lastly the enabling elements (anchors, intermediaries, infrastructure, networks) are chosen in the “HOW” platform, considering local capacity and realities. Importantly, the approach remains adaptive, acknowledging that desired elements may not always be present, necessitating either phased development or immediate pragmatic choices. The framework offers a cohesive blueprint for South African municipalities to effectively implement the national innovation-driven LED Framework 2018-2028. South Africa having chosen innovation to drive LED, this proposed governance framework allows a logical selection of the innovation-driven, private sector-driven hybrid, and knowledge-based approach, positing that a sustainable Local Economic Development (LED) governance process must recognise the interdependent triad of innovation, private sector leadership, and knowledge intensity to be succesful. Innovation, as a driver of LED, requires an enabling environment that fosters private sector leadership, which, in turn, presupposes a knowledge-based economic governance architecture. This ensures LED is not aspirational but practically executable, grounded in clear mechanisms, data-informed strategies, and cross-sector collaboration. Moreover, the proposed governance framework offers a replicable pathway for translating policy into practice, unlocking LED’s full transformative potential, which is locally grounded, but globally relevant. Wherefore, from the policy perspective this study provides a comprehensive blueprint to transform South Africa’s rural LED by addressing critical shortcomings in the National Framework for Local Economic Development (LED) 2018–2028. First, it identifies the need to reposition the private sector as lead co‑creators—rather than peripheral participants—by formally embedding business chambers and forums into Integrated Development Plan (IDP) processes and making private sector consultation and leadership mandatory. Second, it introduces a practical governance framework aligned with the DST’s Innovation‑for‑LED (ILED) initiative and which must be piloted through the District Development Model (DDM). This model incorporates multi‑stakeholder platforms, standardized project tools, and performance monitoring systems, offering municipalities a scalable structure to boost coherence and accountability. Implementation hinges on building institutional capacity in rural municipalities. The study recommends targeted training programs for LED officials covering stakeholder engagement, value‑chain facilitation, project management, and digital monitoring tools. It further proposes institutionalizing public‑private dialogue (PPD) platforms co‑chaired by private sector actors and universities, guided by clear protocols on frequency, scope, and follow‑up. These platforms would serve as engines for knowledge management and innovation. On the fiscal front, the study advocates for performance‑linked grants and competitive LED innovation funds to incentivize municipalities to achieve measurable private sector participation, such as procurement localization rates, co‑infrastructure investments, and job creation via PPPs and CSIs. It also underscores the role of development partners and civil society in supporting framework adoption, recommending targeted piloting in Limpopo districts with international donor and institutional technical assistance. Institutional realignment is another key finding: responsibility for LED must shift from CoGTA and CoGHSTA to an economic development ministry—either via reinstating the Department of Economic Development or a reassignment to DTIC. At provincial level, LED oversight should align with Economic Development, Tourism, and Environment departments, with formal coordination mechanisms to link provincial, municipal, and national policy. Further, the Department of Small Business Development (DSBD) and its agency Small Enterprise and development Agnecy (SEDFA) currently perform welfare-style interventions—providing equipment and starter goods to micro/informal enterprises—which aligns more with social protection than market-based enterprise development. These micro-targeted supports overlook medium and large firms, which are vital for CSI, PPPs, and value chain integration critical to local economic development. Consequently, DSBD and SEDFA’s current mandate is misaligned with the NFLED’s private-sector growth objectives. Their national coordination role would be better housed under a re‑established Economic Development department or within DTIC, which has stronger linkages to industrial strategy and larger enterprises essential for transformative LED. Finally, the study links LED reform to the SDGs—particularly Goals 8, 9, and 17—by embedding SDG‑aligned indicators into municipal LED metrics and enhancing transparency, innovation, and data‑driven decision‑making. This positioned framework supports inclusive, private‑sector-driven hybrid growth, transforming LED from a bureaucratic process into a dynamic engine of rural transformation.
Open Access
AB INITIO and DFT computational study of Myristinin A and A structurally- related molecule
(2019-09-20) Tshilande, Neani; Mammino, Liliana; Ghio, Caterina
The computational study of biologically active molecules is particularly important for drug development because it provides crucial information about the properties of a molecule, which determine its biological activities. The current work considers the results of a computational study of myristinin A and a structurally-related molecule (2-(4-hydroxyphenyl)-4-[2,4,6-trihydroxy-3-(9tetradecenoyl)phenyl]-3,4-dihydro-2H-benzopyran-7-ol, here denoted as DBPO). The two compounds pertain to the class of acylphloroglucinols. They were firstly isolated from Horsfieldia amygdaline, and they exhibit a variety of biological activities, including potent anti-inflammatory activity, potent DNA-damaging activity and DNA-polymerase ß inhibition. Their molecular structures differ only by the acyl chain. Both molecules have a bulky substituent meta to the acyl group consisting of a ring system (2-(4-hydroxyphenyl)-3,4-dihydro-2H-chromen-7-ol). The DBPO molecule can exist as cis and trans isomers in relation to the double bond present in the R chain, and both isomers are here investigated individually. The OHs ortho to the acyl group can form an intramolecular hydrogen bond (referred to as the first IHB) with the sp2 O atom of the acyl group. The phenol OHs neighbouring the substituent ring system can form O–Hπ interaction with the aromatic rings of the substituent, if suitable oriented. This study focuses on the identification of the stable conformers of these molecules (considering all the possible geometries obtainable by rotations about relevant single bonds), and of the factors stabilising the conformers. Full-optimisation calculations were performed in vacuo and also in three conveniently selected solvents. The results show that the dominant stabilising factors are the first IHB and the O–Hπ interactions. Other factors which have significant influence on conformational preferences are the orientation of the ring systems of the substituent, the orientation of the OHs on substituent, the mutual orientation of the OHs of the phloroglucinol moiety and also the orientation of the acyl chain. The results in solution are consistent with the findings of other acylphloroglucinols, for instance, the narrowing of the energy gaps and the increase of the dipole moment with the increase of solvent polarity.
Open Access
Access and constraints to commuting in Gauteng Province, South Africa
(2016-05) Chakwizira, James; Bikam, Peter; Adeboyejo, Aina Thompson
See the attached abstract below
Open Access
Activity patterns, species composition and dietary analysis of bats on two macadamia farms in Levubu, South Africa
(2017-09-18) Mphethe, Vusani; Taylor, P. J.; Steyn, J. N.; Schoeman, M. C.
See the attached abstract below
Open Access
Adaptation strategies for climate change-induced household food and nutrition insecurity in smallholder maize farming within Thulamela Local Municipality, South Africa
(2017-09-18) Mahlawule, Khanyisa Dorris; Francis, J.; Manjoro, D.
See the attached abstract below
Open Access
Adaptive Strategies to Mitigate Water Scarcity Among Smallholder Cattle Farmers in Vulnerable Areas of the Greater Tzaneen Local Municipality
(2024-09-06) Mahlo, Dollen; Manjoro, M.; Oloo, G. B.; Mkhwanazi, M. V.
The rapid increase in demand for livestock and livestock products, driven by factors such as population growth, urbanization, and rising incomes, is projected to escalate significantly by 2050. The estimates indicate the utilization of over 60 billion livestock for meat, egg, and dairy production. This surge in demand poses substantial challenges, particularly in the context of climate change impacts on water resources. Smallholder livestock farmers, who are integral to meeting this demand, are disproportionately affected by climate change-induced water scarcity. Despite their significant contribution to the agricultural Gross Domestic Product (GDP), these farmers face daily depletion of water reserves, indicating severe water scarcity. Climate variability further exacerbates this situation, with animal water consumption expected to triple. This study aimed to examine the adaptive strategies employed by smallholder livestock farmers in vulnerable areas of the Greater Tzaneen Local Municipality to mitigate water scarcity. A convergent parallel mixed methods design was utilized, wherein both quantitative and qualitative data were collected and analyzed concurrently. Purposive sampling was used to select participants, primarily through face-to-face interviews. Secondary data was obtained from literature, journal manuscripts, policy documents, and municipal reports. Quantitative data were analyzed using the Statistical Package for Social Sciences (SPSS) version 27, while thematic content analysis was performed using Atlas.ti version 8. The findings revealed several adaptive strategies employed by farmers to address water scarcity, including changes in water sources and collaborations with government agencies such as the Department of Water and Sanitation. Challenges such as cattle mortality due to water scarcity were also identified, highlighting the need for additional adaptive measures to ensure sustainable cattle farming. The study underscores the necessity of enhancing adaptive strategies to mitigate the adverse effects of water scarcity on smallholder livestock farming in the context of increasing climate variability.
Open Access
Adoption of survival strategies by agro-small and medium enterprises in the challenging rural environment in Zimbabwe
(2014-12-11) Shoko, Dumisani; Oloo, D.; Francis, J.
There is worldwide consensus among policy makers, economists and business experts that Small and Medium Enterprises (SMEs) contribute substantially to aggregate economic growth. Agro-SMEs in particular, are regarded as the engines of economic growth and catalysts of socio-economic transformation in many countries. However, the resilience of agro-SMEs is increasingly becoming questionable due to a number of challenges which include, economic recession and climate change. Economic recession and climate change pose formidable challenges to the survival and growth of agro-SMEs. These complex challenges and barriers compel! agro-SMEs to adopt survival strategies in order to remain operational. Strategies that can appropriately enhance the resilience of agro-SMEs to shocks and how best to implement them, are still unknown. Thus, this case study investigated the survival strategies that were adopted by agro-SMEs in Kwekwe District of Zimbabwe in response to economic recession and climate change induced-stress between the year 2000 and 2010. All the agro-SMEs established before 2005, that survived the 2000-2010 challenging operating environment and were still operational during the time of the research, constituted the study population. Purposive sampling in the form of total population sampling was used. The main data collection tools that were used to gather data to answer the objectives of the study are appreciative inquiry, using key informant interviews and questionnaire survey; preference ranking using matrix scores; data mining of records kept by agro-SMEs government publications, journals and related books; and comparative scaling. The Statistical Package for Social Sciences (SPSS) was used to analyse the data. Thematic content analysis, frequency distribution analysis, measures of central tendency and the Binary Logistic Regression Model were used to analyse specific objectives of the study. Results show that a variety of strategies are available for adoption by agro-SMEs operating in a challenging environment. Adoption rates and preferences varied from one strategy to the other. Contribution of these strategies towards agro-SME survival also varied from no contribution at all to marginal to significant or very significant contribution.The study's results provide compelling scientific information that will act as a guideline on the strategies that can be adopted in challenging operating environments. This will also assist in the creation of a better platform for the implementation of improved agro-SME development strategies.
Open Access
Adsorption of oxyanions of As, B, Cr, Mo and Se from coal fly ash leachates using A1/Fe modified bentonite clay
(2014-01-10) Masindi, Vhahangwele; Gitari, Wilson Mugera; Tutu, Hlanganani
South African coal-fired power stations rely on the use of low grade bituminous coal for electricity generation. During coal combustion processes, this type of coal generates large volumes of waste materials which include Fly ash, bottom ash, boilers slag, flue gas desulphurization and un-captured particles. From the array of generated residues, coal fly ash constitute 90% and of this only 5% is beneficially used with the rest being disposed-off to land as ash dumps or slurried to ash retention ponds. On disposal, coal fly ash leaches out toxic chemical species on contact with the aqueous media hence posing hazardous effects to the aquatic and terrestrial environment. Of prime concern are Oxyanionic species such as As, B, Cr, Mo and Se. This study aims to investigate the adsorption of As, B, Cr, Mo and Se from coal fly ash leachates on Al3+/Fe3+modified bentonite clay. Coal fly ash samples used in this study were collected from Tutuka, ESKOM power plant in Mpumalanga and Bentonite clay samples were collected from ECCA (pty) Ltd. pH, Electrical Conductivity (EC) and Total Dissolved Solids (TDS) of the samples were determined using a CRISON multimeter probe. Modifications of bentonite clay with Al3+ and Fe3+ cations were done in batch procedures and the parameters optimized included contact time, adsorbent dose and adsorbate concentration. Cation Exchange Capacity (CEC), Point of Zero Charge (pHpzc) and Water Holding Capacity (WHC) of raw and modified bentonite clay were determined using standard methods. Surface areas of raw and modified bentonite clays were determined by BET. Elemental composition of raw and modified bentonite clay was determined by XRF and Mineralogical composition of raw and modified bentonite clay was determined by XRD. AAS and GFAAS were used to monitor AI3+and Fe3+concentration in the reaction mixture during and after modification while As, B, Cr, Mo, and Se were monitored using GFAAS, ICP- OES and JCP- MS. Adsorption of oxyanions of As, B, Cr, Mo and Se was carried out in batch experiments using synthetic solutions of the species. Effects of contact time, adsorbent dosage, adsorbate concentration and pH on the adsorption of As, B, Cr, Mo and Se were evaluated and optimized. The modification experiments revealed that loading of Al3+ onto bentonite clay interlayers is optimum at 60 minutes of contact time, 3 grams of adsorbent and 100 mg/L of adsorbate concentration and loading of Fe3+ onto bentonite clay matrices is optimum at 15 minutes of contact time, 2 grams of adsorbent and 100 mg/L of adsorbate. The CEC results showed that South African bentonite clay is characterized by high CEC of262 meq/l00g at pH 5.4 and 265.5 meq/l00g at pH 7.4 which decreased to 186.9 meq/l00g at pH 5.4 and 183.3 meq/l00g at pH 7.4 on introducing Al3+ onto bentonite clay interlayers and 195.5 meq/100g at pH 5.4 and 188.9 meq/100g at pH 7.4 on introducing Fe3+ onto bentonite clay interlayers. The results show that CEC is independent of pH. BET results indicated that the loading of Al3+ onto bentonite clay interlayers increased the surface area from 16 m2/g to 44.3 m2/g and 50 m2/g for Fe3+,external surface area from 11.1 m2/g to 33.1 m2/g for Al3+ and 37.4 m2/g for Fe3+,micro-pore area from 4.9 m2/g to 11.2 m2/g for AJ3+ and 12.5 m2/g for Fe3+. There was a slight difference in pHpzc of Al3+ modified bentonite clay (8.2) as compared to raw bentonite (8.0). For Fe3+ modified bentonite clay, the pHpzc was observed to increase from 8.0 for raw bentonite clay to 9.0. An increase in pHpzc shows that modification will favour adsorption of anions from aqueous media. WHC of bentonite clay was determined to be 42.7%. Elemental composition by XRF showed SiO2, AhO3, Fe2O3, CaO, Na2O, K2O and MgO as the major chemical species. XRF results also confirmed that bentonite clay is an aluminosilicate material. XRD disclosed that bentonite clay is dominated by montmorillonite as the major mineral phase. Characterization of fly ash leachates revealed that coal fly ash leachates contains 53 µg/L of As, 1730 µg/L of B, 271 µg/L of Cr, 165 µg/L of Mo and 170 µg/L of Se. Adsorption of As, B, Cr, Mo and Se onto Al3+ modified bentonite clay revealed that 30 minutes of contact time, 4 grams of adsorbent dosage, 10 mg/L of adsorbate concentration and pH 10 are the optimum conditions for removing those species from aqueous media. The adsorption affinity of those species obeyed the following order: B = Se > Mo = Cr > As. Adsorption of As, B, Cr, Mo and Se onto Fe3+ modified bentonite clay revealed that 30 minutes of contact time, 4 grams of adsorbent dosage, 10 mg/L of adsorbate concentration and pH 10 are the optimum conditions for removing those species from aqueous media. The adsorption affinity of those species obeyed the following order: B = Se > Mo > Cr = As. The adsorption capacities of modified bentonite clays were greater than the adsorption capacities of raw bentonite clay. The data fitted well to both Langmuir and Freundlich adsorption isotherm hence showing that the adsorption is energetically favourable. The unmodified clay showed poor adsorption for these chemical species. Both Al3+ and Fe3+ modified bentonite clay successfully removed As, B, Cr, Mo and Se from generated coal fly ash leachates to below DWAF water quality guidelines at the optimized conditions. This shows that AJ3+ or Fe3+ modified bentonite clay is an effective adsorbent for removal of oxyanionic species of As, B, Cr, Mo and Se from coal fly ash leachates and could be applied as a reactive barrier or liner in ash retention ponds.
Open Access
Agronomic evaluation of chickpea (Cicer arietinum L.) genotypes in contrasting agro-ecological regions of Limpopo and Mpumalanga Provinces
(2020-02-24) Shilenge, Siphiwe Kim; Ogola, J. B. O.; Odindo, A.
Chickpea (Cicer arietinum L.) is an important grain legume in the world, ranking second after soybean (Glycine max L.). It accounts for a substantial proportion of human dietary nitrogen intake and plays a crucial role in food security in developing countries. Chickpea can grow in areas with low rainfall and poor soils, and thus may be an important food security crop for smallholder resource-poor farmers in the semi-arid tropics such as the dry environments of the Limpopo and Mpumalanga Provinces of South Africa. Preliminary studies showed the huge potential of chickpea production in these environments. However, no suitable genotypes have been identified and recommended for different agro-ecological zones of Limpopo and Mpumalanga Provinces. Therefore, the objective of this study was to evaluate the performance, and hence, identify the genotypes that are adapted/suitable to the contrasting agro-ecological conditions of Limpopo and Mpumalanga Provinces for production. Field experiments were conducted in the winter cropping seasons of 2016 and 2017 at Thohoyandou (University of Venda experimental station), Syferkuil (University of Limpopo experimental station) and Nelspruit (University of Mpumalanga experimental station). Ten desi chickpea genotypes were sown in a completely randomized block design replicated three times on 10 May 2016 and 10 April 2017 (Thohoyandou), 13 May 2016 and 11 April 2017 (Syferkuil) and 03 May 2016 and 24 May 2017 (Nelspruit). Plant growth characteristics were assessed by determining plant height, crop phenology, number of primary and secondary branches, and canopy cover. Yield and yield components were assessed at harvest after physiological maturity. Carbon dioxide exchange rates (CER) was determined at different growth stages using the InfraRed Gas Analyzer (IRGA). Chlorophyll content (CC) and intercepted radiation were determined weekly using the chlorophyll content meter (CCM-200 PLUS, Opti-Science, Tyngsboro, Massachusetts), and the AccuPAR, LP-80 ceptometer (Deacon Devices Ltd., Pullman, USA), respectively. Genotypes did not vary in CC at Thohoyandou in all seasons, but CC increased with stages of growth. Genotypes varied in the proportion of intercepted radiation (IR) at all measurement dates in Thohoyandou during the 2016 and 2017 growing seasons. The proportion of IR increased with growth stage, reached a peak and declined with plant age. Genotype affected photosynthesis and intercellular CO2 concentration (Ci) but did not have any significant effect on stomatal conductance (gs), transpiration (T) and Leaf Vapour Pressure Deficit (VPDL) during the 2016 season in Thohoyandou. In contrast, genotype did not affect photosynthesis, Ci, gs, T and VPDL in the 2017 season in Thohoyandou. There was no variation among genotypes on number of primary and secondary branches in Thohoyandou in both seasons. Genotypes showed no variation in plant height in the 2016 season in Thohoyandou agro-ecological condition. However, genotypes showed significant variation in plant height at 14, 70 and 84 days after emergence (DAE) in the 2017 cropping season. Moreover, genotypes showed significant variations in days to 50% flowering in Thohoyandou during the 2016 season, but showed no variations in days to 50% emergence and 75% physiological maturity. Genotypes showed no variations in days to 50% emergence, 50% flowering, 50% podding and 75% physiological maturity in the 2017 season in all locations. Genotypes showed significant variation in grain yield in Syferkuil agro-ecological condition, but showed no significant variations on all the other studied traits, while genotypes varied in 100 seed weight (SW) in Thohoyandou, but did not show any variations on the other studied traits during the 2016 season. Moreover, genotypes did not vary for all studied traits in Nelspruit during the 2016 season. The 2016 genotype and environment (G X E) interaction results showed no significant variations. However, results showed G X E interactions during the 2017 growing season suggesting that genotypes responded to environmental variation in a different way. Syferkuil had the greatest grain yield (2811 kg ha-1 and 3122 kg ha-1) in both the 2016 and 2017 growing seasons respectively, as compared to Thohoyandou and Nelspruit. These preliminary findings show that the studied genotypes responded differently in contrasting agro-ecological regions of Limpopo and Mpumalanga Provinces and that Syferkuil might be the best environment for chickpea production in this region due to its cooler temperatures. Of the genotypes evaluated the most promising genotypes are ICCV8101, ICCV3203 and ICCV4110 in these regions in terms of grain yield.
Open Access
Alternative methods for solving nonlinear two-point boundary value problems
(2018-03-18) Ghomanjani, Fateme; Shateyi, Stanford
In this sequel, the numerical solution of nonlinear two-point boundary value problems (NTBVPs) for ordinary di erential equations (ODEs) is found by Bezier curve method (BCM) and orthonormal Bernstein polynomials (OBPs). OBPs will be constructed by Gram-Schmidt technique. Stated methods are more easier and applicable for linear and nonlinear problems. Some numerical examples are solved and they are stated the accurate findings.
Open Access
Alternative practices for optimising soil quality and crop protection for macadamia orchards, Limpopo Province, South Africa.
(2019-09-30) Steyn, Jakobus Nicolaas; Crafford, J. E.; Gliessman, S. R.; v. d. M. Louw, S.
The main aim of the research was to contribute means for converting conventional, high-input production systems to more sustainable ecological systems, thereby improving the sustainability of macadamia production and ultimately contributing to food security. This was achieved by a) investigating the potential use of cover crops and compost to enhance soil quality in macadamia orchards and b) investigating the potential use of use of cover crops and orchard heterogeneity to control stinkbug pests that target macadamia crops. Field experiments were conducted in three phases: phase one tested the potential of six cover crops for crop protection (as trap crops) and simultaneously for soil restoration or fertility enhancement purposes in macadamia orchards. Phase two repeated the trials of phase one (both soil restoration and trap crops) but with modifications to both categories. Soil restoration treatments were conducted with trees which were growing in what appeared to be healthy soils, and then repeated with trees in the same orchard where the topsoil had been degraded (totally removed) by agricultural operations. The third phase repeated the trap crop trials only, but this time on three different study areas (all commercial farms) with the single cover crop which performed the best as a trap crop during phase two. Trials were modified from the first to the last phase to overcome practical implementation problems encountered along the way and to adapt to local conditions experienced in the commercial macadamia farming systems which served as research sites. Diversity of natural orchard vegetation was enhanced in phase three to improve conditions for natural predators as part of the trap crop treatments in the last phase and cover crops were finally first composted and then returned to the root zones of the macadamia trees as part of the soil quality enhancement treatments in the second phase. The results from the trap crop trials shows a significant effect of trap crops combined with increased orchard diversity in reducing unsound kernel percentages caused by stinkbug pests and demonstrate that trap crops combined with an increase in orchard diversity could be utilized in macadamia orchards as a more sustainable alternative to inorganic pesticides against the stinkbug complex. The most notable changes in the soil that took place with soil quality enhancement treatments were the significant increases in soil phosphorous content and pH which resulted not in an improvement in soil quality in terms of these two indicators but revealed an important issue about the use of compost containing animal manure originating from dairies or feedlots. In summary however, it was clear that although not all the soil quality indicators that were employed to assess changes in the soil with compost treatments improved significantly, a holistic consideration of all indicators portrays an overall improvement which was particularly significant in the degraded soil plots where the topsoil had been removed by prior agricultural activities.
Embargo
Ambient air pollution monitoring, modelling and human health risks in Thulamela Municipality, Vhembe District of Limpopo Province, South Africa
(2025-09-05) Enitan, Ibironke Titilayo; Edokpayi, J. N.; Piketh, S. J.
Ambient air pollution is a pressing global environmental concern, with pollutants from natural and anthropogenic sources contributing to deteriorating air quality. This research investigates the impact of sulfur dioxide (SO₂), nitrogen oxides (NOₓ), carbon monoxide (CO), and particulate matter (PM2.5 and PM10) on human health and the environment. PM2.5 in particular is a significant public health risk linked to respiratory and cardiovascular diseases. The study focuses on Thulamela Local Municipality (LM) in Limpopo Province, South Africa, a region with diverse semi-urban and rural environments, where air quality data is limited despite ongoing urbanisation and economic growth. Given the lack of comprehensive baseline data, this study aims to quantify, monitor, and model air pollution while assessing its potential health impacts. This research integrates the development of an emission inventory for criteria pollutants (SO₂, NOₓ, CO, PM2.5, and PM₁₀), real-time PM2.5 monitoring using Dylos DC1700 low-cost sensors (LCSs), PM2.5 dispersion modelling with AERMOD, health risk assessment (HHRA), and machine learning-based predictive modelling. By evaluating pollution sources, exposure risks, and predictive trends, the study provides critical insights to inform air quality management strategies in semi-urban settings. This study developed the first-ever 10-year vehicle emission inventory (VEI) for criteria pollutants (SO₂, NOₓ, CO, PM2.5, and PM₁₀) in Thulamela Local Municipality (LM), South Africa. In addition, it produced the first comprehensive bottom-up emission inventory for the year 2021, quantifying total SO₂, NOₓ, CO, PM2.5, and PM₁₀ emissions from two major anthropogenic sources: vehicular emissions and residential wood combustion (RWC). The results indicated annual emissions of 66.3, 1821.7, 21002.6, 2348.7, and 2649.3 tonnes, for SO₂, NOₓ, CO, PM2.5, and PM₁₀, respectively. RWC contributed over 96% of PM2.5 and PM₁₀ emissions, while NOₓ (84%) and SO₂ (60%) originated primarily from vehicular sources. The spatial analysis revealed that emissions were highest in the southwest and northwest, where population density and human activities were most concentrated. A one-year PM2.5 monitoring campaign (March 2021 – February 2022) was conducted at 14 sites, covering urban, suburban, and rural areas. The strong correlation (R² = 0.75) between Dylos and reference monitors (GRIMM EDM180) confirmed the reliability of LCS performance for PM2.5 measurements. The study found that annual PM2.5 concentrations exceeded both WHO guidelines and SA NAAQS, except at one site. Monthly trends showed higher PM2.5 levels from May to September, with diurnal peaks from 6–8 am and 6–8 pm, primarily influenced by traffic emissions and residential wood combustion. The bivariate polar plot (BVP) analysis identified pollution hotspots near traffic intersections, residential areas, and commercial zones. The study identified significant spatial and temporal variations in PM2.5 levels across different monitoring sites, with higher concentrations in suburban areas than rural ones due to vehicular emissions and wood-burning. VTV2 recorded the highest annual concentration (32.3 μg/m³), while RL4 had the lowest (19.1 μg/m³). The average seasonal PM2.5 levels, despite differences, consistently exceeded air quality guidelines, except in summer for specific locations. The results also showed that evening PM2.5 concentrations were generally higher than morning peaks, highlighting significant differences in pollution levels across the area. Using AERMOD, PM2.5 dispersion was modelled to assess spatial patterns and regulatory compliance. Results showed that pollution hotspots exceeded SA NAAQS (40 μg/m³ daily, 20 μg/m³ annually) and WHO standards (15 μg/m³ daily, 5 μg/m³ annually), with the highest daily PM2.5 concentration (49.2 μg/m³) in densely populated areas. Model validation comparing modelled and monitored PM2.5 showed systematic underestimation (R² = 0.176, negative fractional bias), indicating unaccounted sources such as biomass burning, unpaved roads, industrial activities, and agricultural emissions. At Lunungwi village (RL receptor group), the modelled hourly PM2.5 concentration (47.12 μg/m³) exceeded the observed value (32.27 μg/m³, FAC2 = 0.25), indicating localised overestimation. Daily peaks aligned with morning and evening rush hours. At the same time, monthly trends from May to September reflected seasonal variations and increased residential wood combustion, while a notable decline in July 2021 was due to COVID-19 lockdown restrictions, highlighting the impact of reduced human activity on air quality. Although AERMOD has limitations in accounting for some emission sources, it effectively identified pollution hotspots, offering valuable insights for policy interventions and air quality management. The study further assessed long-term exposure and health risks using the HHRA model, focusing on risk characterisation. The USEPA health risk assessment revealed that PM2.5 exposure posed both non-carcinogenic and carcinogenic risks, with infants and toddlers being the most vulnerable. Hazard Quotient (HQ) values exceeded safe limits (1.10 in winter) due to high PM2.5 levels in colder months. Excess Lifetime Cancer Risk (ELCR) values surpassed the acceptable threshold (10⁻⁴) for all age groups, with adults facing the highest long-term cancer risks (2.35 × 10⁻¹). These findings emphasise the urgent need for air pollution control measures, particularly in areas with high residential fuel combustion and vehicular emissions. To enhance PM2.5 predictions, machine learning models were applied using meteorological variables. Random Forest (RF) outperformed Multiple Linear Regression (MLR) and Polynomial Ridge Regression (PRR), with the highest R² (0.80) at VP4 for site-specific predictions and 0.604 for area-wide estimates. Seasonal performance showed better RF accuracy in winter (R² = 0.58, RMSE = 2.10 μg/m³) than in summer (R² = 0.45, RMSE = 4.72 μg/m³), reflecting the impact of seasonal meteorology on PM2.5 dispersion. In conclusion, this research provides a holistic approach to quantifying air pollution sources, exposure risks, and predictive modelling in Thulamela Municipality. The study highlights urgent public health risks and the need for stronger air quality regulations, improved monitoring networks, and targeted mitigation strategies by establishing a clear link between air quality and human health. The findings underscore the need to expand emission inventories, refine meteorological inputs, and integrate multi-pollutant assessments to develop a comprehensive air quality management strategy. To address identified challenges, the study proposes mitigation strategies, including eco-friendly phytoremediation techniques, promotion of cleaner cooking and transport technologies, and urban planning measures to minimise exposure in densely populated areas. By combining scientific research with practical applications, this work aims to support sustainable air quality management, improve public health, and contribute to a healthier environment.
Open Access
An analysis of exposure and slope gradient impact on tree layer profile of Maroelakop vegetation in Nylsvley Nature Reserve, Limpopo Province, South Africa
(2024-09-06) Mavhila, Tendani; Tshisikhawe, M. P.; Magwede, K.
Since the 1850s, plant ecologists have been eager to investigate challenges in vegetation communities that are related to slope. The aspect of the slope is crucial in terms of the diversity and distribution of plants. This research was conducted on Maroelakop Mountain within Nylsvley Nature Reserve located in Mookgopong, Limpopo Province. The investigation aimed to assess and contrast the vegetation composition on the north-facing slope with that of the south-facing slope. The specific goals included ascertaining the density and frequency of dominant tree species on each slope, calculating the importance value indices of trees on both slope gradients and analyzing the population structure of the slope gradient. Point Centred Quarter (PCQ) was used in data collection. Shannon-Weiner diversity index, Simpson diversity index, and Evenness index were used to measure plant species diversity. In this study, a total of 600 trees were discovered and identified by their botanical names. The data represented 21 plant species in 17 genera and 12 families. The tree layer of the north-facing slope was dominated by Diplorhynchus condylocarpon, whereas that on the south-facing slope was dominated by Burkea africana. Both tree species had high-importance value indices. Shannon diversity index of 2.20 was obtained for the North-facing downslope, whereas the South-facing downslope had 1.74. The average Simpson diversity index for the North-facing slope was 0.82 and South-facing slope 0.77. The average Evenness index for the North-facing slope was 0.93 and, on the South-facing slope 0.81. This study concluded that Diplorhynchus condylocarpon is the most prevalent species within Maroelakop Mountain in the Nylsvley Nature Reserve.
Open Access
An evaluation of flood control mechanisms to withstand and adapt to flooding in Vhembe District, Limpopo Province
(2024-09-06) Munzhedzi, Lily; Nethengwe, N. S.; Mugari, M. E.
The Vhembe district is currently grappling with a rising prevalence of flooding, a phenomenon attributed to a combination of natural elements, such as heavy rainfall, and human-induced activities like deforestation and inadequate infrastructure management. The resultant damages encompass infrastructure destruction, loss of life, crop and soil damage, and environmental harm, with implications extending to human health, housing, livelihoods, government resources, and significant economic consequences. Consequences vary based on the resources and development levels of different areas, emphasising the need to understand each community's unique aspects for the development of resilient flood control strategies. The aim of this study is to evaluate the flood control mechanisms to determine if they can withstand and adapt to flooding in the selected study areas of Musina, Duthuni, and Sane in the Vhembe District. The study pursues two objectives: investigating trends in extreme rainfall and its relationship to flood occurrences, and characterising the nature, effectiveness, and adaptability of flood control mechanisms in the Vhembe district area. Employing a mixed-methods approach, the research design integrates both quantitative and qualitative methods to gain comprehensive insights. The data collection process involved the administration of in-depth questionnaires to participants, coupled with observational analyses of flood control mechanisms. This multifaceted approach allowed for a qualitative assessment of the nature, effectiveness, and adaptability of these mechanisms. Additionally, daily rainfall data sourced from the NASA POWER website was utilised. This data facilitated the computation of an average seasonal precipitation table, the generation of monthly precipitation figures, and tables displaying the count of days when precipitation exceeded the 95th percentile. The findings reveal a recurring pattern of precipitation throughout the seasons, with the highest average precipitation consistently occurring from December to February, and January emerging as a critical month for flood risk. The analysis of flood events spanning from 2000 to 2020 establishes a connection between daily rainfall exceeding 20 mm and instances of flooding, particularly evident in Duthuni, where nearly annual flooding has been observed. The study identified diverse flood control mechanisms linked to the level of development and community traditions. Natural and traditional measures, such as furrows and vegetation-based flood control mechanisms, dominate the rural village of Sane. In contrast, the urbanised Musina prefers engineered solutions like culverts and concrete channels, while Duthuni integrates both approaches. Furrows are popular at the household level across all the study areas, although their effectiveness is considered to be lower in comparison to other household flood control mechanisms. The field observational analysis emphasises the construction of flood control mechanisms using reinforced materials and underscores the importance of regular maintenance. The study underscores the importance of region-specific flood control solutions tailored to local conditions and preferences, considering climate patterns and community traditions. By adopting this approach, the Vhembe district can enhance its readiness and adaptive capacity for flooding. The study's results provide a foundation for well-informed decision-making and policy development, emphasising the necessity for initiatives to align flood management with the distinct challenges and preferences of local communities.
Open Access
An investigation of hygiene practices in butcheries and the prevalence of antibiotic resistant Listeria monocytogenes in Limpopo, South Africa
(2024-09-06) Siluma, Bridget; Ramashia, S. E.; Nethathe, B.; Kgatla, T. E.
Listeria monocytogenes is a foodborne bacterial pathogen associated with serious public health and food safety problems. It is an intracellular microbe that causes Listeriosis, a life-threatening disease that yields to bacteremia, meningitis, and spontaneous miscarriage. This study aimed to conduct the survey and investigate the prevalence and antibiotic susceptibility of L. monocytogenes from butcheries (village & commercial) and supermarkets beef plate meat in the Vhembe district. Evaluation of meat safety practices and hygiene among different butcheries and supermarkets was conducted using a questionnaire. The prevalence of L. monocytogenes in retail beef plate meat was determined on chromogenic agar and the antibiotics susceptibility was examined from L. monocytogenes isolates using the well diffusion method. The results of this study revealed that (i) some supermarkets followed the meat safety practices and hygiene, whereas there was a combination of good and unhygienic meat handling practices identified at commercial and village butcheries (ii) L. monocytogenes were identified in high numbers however some other species of Listeria such as L. ivanovii and L. innocua were found in beef plate meat (iii) The Listeria isolates were resistant to a wide range of antibiotics used to treat human listeriosis such as ampicillin, tetracycline and nalidixic acid in large numbers while a few of the isolates were susceptible to sulphamethoxazole and intermediary responsive to oxytetracycline and chlortetracycline. The findings from this study concluded that some supermarkets follow the safety procedures while commercial and village butcheries do not follow the procedures and regulations, furthermore, the prevalence of the pathogenic L. monocytogenes may harm the communities around Vhembe district. Moreover, treatment in case of an outbreak may become burdensome as the pathogen may be resistant to antimicrobial treatment. It is recommended that intervention through training on food safety to improve the hygienic practices of meat handling along the beef supply chain, more especially within commercial and village butcheries be conducted, also L. monocytogenes control measures from relevant authorities need to be put in place, meat must be prepared adequately, and antibiotics must be utilized appropriately. In addition, conducting molecular research on Listeria species to determine the virulence genes present in L. monocytogenes isolated from retail beef, to keep track of the type of strains of Listeria that may be circulating in the Vhembe district is recommended.