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Recent Submissions

The analysis ready multispectral data and machine learning algorithms for mapping groundwater-dependent invasive alien plants in Heuningnes Catchment, South Africa
(Taylor and Francis Ltd., 2026) Moropane, Mmasechaba L.; Dube, Timothy; Shoko, Cletah; Masocha, Mhosisi
Field monitoring of groundwater-dependent invasive alien plants (GDIAPs), though accurate, is spatially limited and prone to misclassification bias. Satellite imagery and machine learning algorithms (MLAs) offer scalable alternatives, yet their effectiveness in mapping GDIAPs remains underexplored. This study assessed Sentinel-2 and Landsat-8 data using five MLAs with pixel- and object-based approaches to delineate GDIAPs within groundwater-dependent ecosystems (GDEs) of the Heuningnes Catchment. Pixel-based random forest (RF) achieved the highest overall accuracies (98% with Sentinel-2, 94% with Landsat-8), while object-based gradient tree boosting (GTB) using Sentinel-2 achieved 85%, outperforming RF (82%). The class-specific F1-scores for GDIAPs and native plants exceeded 90% when pixel-based RF classifications were used. The Sentinel-2 pixel-based RF results indicated that GDIAPs dominated 26.8 km² (60%) of GDEs in 2022, compared to 13.6 km² (31%) of GDEs occupied by native fynbos. These findings demonstrate the value of satellite-based machine learning for monitoring GDIAPs and supporting invasive species management, ecosystem protection, and water resource planning.
Discovery of a years-delayed radio flare from an unusually slowly evolving tidal disruption event candidate
(American Astronomical Society, 2026) Zhang, Zhumao; Shu, Xinwen; Yang, Lei; Sun, Luming; Ding, Hucheng; Yan, Lin; Jiang, Ning; An, Fangxia; Shu, Xinwen; Zhang, Zhumao; Chandola, Yogesh; Wu, Zhongzu; Liu, Daizhong; Dou, Liming; Wang, Jianguo; Wang, Yibo; Yang, Chenwei; Li, Di; Zhou, Tianyao; Peng, Fang Kun; Wang, Tinggui; Wang, Tinggui
SDSS J1115+0544 is a unique low-ionization nuclear emission-line region galaxy with energetic ultraviolet (UV), optical, and mid-infrared outbursts occurring in its nucleus. We present the results from an analysis of multiwavelength photometric and radio follow-up observations with a time span of ≈9 yr since its discovery. We find that following a luminosity plateau of ≈500 days, the UV/optical emission has decayed back to the preoutburst level, suggesting that the nuclear outburst might be caused by a stellar tidal disruption event (TDE). In this case, J1115+0544 could be an unusually slowly evolving optical TDE with longest rise and decline time scales ever found. Three years later than the optical peak, a delayed radio brightening was found with a luminosity as high as νL ν (5.5 GHz) ∼ 1.9 × 1039 erg s−1. Using a standard equipartition analysis, we find that the outflow powering the radio emission was launched at t ≳ 1150 days with a velocity of v ≲ 0.1c and a minimal kinetic energy of E K ≳ 3 × 1049 erg. The delayed radio brightening coupled with the disappearing plateau in the UV/optical light curves is consistent with the scenario involving delayed ejection of an outflow from a state transition in the disk. SDSS J1115+0544 is the first TDE candidate displaying both a short-lived UV/optical plateau emission and a late-time radio brightening. Future radio observations of these TDEs in the postplateau decay phase will help to establish the connection between outflow launching and changes in accretion rate
Adsorption of rees from aqueous solutions using modified polystyrene- di (2-ethylhexyl) phosphoric acid electrospun nanofibers
(Elsevier B.V., 2026) Mukaba, Jean-Luc; Mouele, Emile Salomon Massima; Ameh, Alechine Emmanuel; Eze, Chucks Paul; Petrik, Leslie; Tshentu, Zenixole R.
The recovery and separation of rare earth elements (REEs) is an emerging area of the current research due to their applications in modern technology and because both accessible and cost-effective approaches are required. In this study, polystyrene (PS) grafted with di(2-ethylhexyl) phosphoric acid (D2EHPA) ligand was fabricated via the electrospinning technique. The electrospun PS/DEHPA nanofiber mats were characterised using various techniques such as HR-SEM, TGA, FTIR, XRD, BET and ICP-OES. The fabricated electrospun nanofiber materials were then used for the recovery of Nd and Sm metal ions from the aqueous solutions. The supreme sorption uptake of Nd3+ and Sm3+was ˃ 100 mg/g at pH 4.0, reached at an equilibrium time of 70 min with the modified PS/DEHPA nanofiber mats. The recovery of Nd3+ and Sm3+was best described by the Langmuir isotherm and followed a pseudo second-order kinetic model. Thermodynamic data, ΔG°, Δ H° and ΔS° suggest that Nd3+ sorption onto PS/DEHPA was spontaneous and endothermic. The coordination of PS with the D2EHPA ligand occurred via hydrogen bonding while the binding of PS/DEHPA to the metal ion was likely bonded by ionic, covalent or electrostatic interactions. The reusability investigation indicates that the synthesized PS/DEHPA nanofiber mats can withstand up to four successive cycles, and the adsorption and desorption performances were over 60 %. Nd3+ sorption in the presence of interfering Ni2+ and Co2+ metals was 96.82 mg g−1(0.671 mmol g−1), closer to 101.46 mg g−1(0.703 mmolg−1) obtained in a single metal ion solution suggesting a good selectivity of PS/DEHPA fibres towards REEs (Nd3+).
Decolonising Tuberculosis treatment pathways: a Participatory Action Research (PAR) approach within the Western Cape, South Africa
(SAGE Publications Inc., 2026) Naidoo, Yuvir; Cupido-Masters, Jill; Christian, Carmen S.
Tuberculosis (TB) continues to pose a major public health challenge in South Africa, particularly in the Western Cape, which records some of the country’s highest TB incidence rates. Despite well-established TB control programmes, treatment access and adherence remain uneven due to structural barriers such as stigma, non-medical patient costs, and rigid clinical routines. Understanding how patients navigate these constraints is essential to improving TB treatment delivery and health outcomes. This paper outlines the qualitative methods used to create a taxonomy of pathways that patients use to access first-line TB treatment in the Western Cape, South Africa. The study was conducted in one substructure of the Cape Metropolitan region and demonstrates a methodological approach that co-creates research with frontline TB staff and key TB stakeholders to ensure that findings are contextually grounded and relevant to real-world service delivery. Using a participatory action research (PAR) framework, combined with a single-round Delphi approach and the SynNovation technique, the study systematically validates consensus among frontline TB staff on process mapping, prioritisation, feasibility, and the impact of TB treatment pathways currently used in the Western Cape. A consensus-building workshop incorporating the SynNovation technique enabled participants to refine and rename the identified pathways, promoting both cultural relevance and linguistic neutrality. The resulting taxonomy reflects staff-derived insights into TB treatment delivery and offers a foundation for future validation from patients. This study represents an initial but meaningful step toward practical decolonisation, as it repositions implementers of TB care as co-creators of knowledge and language.
Jurisdictional immunity in South Africa: interpreting section 2 of the foreign states immunities act in light of article 6(2)(B) of the United Nations convention on jurisdictional immunities of states and their property, 2004, and its drafting history
(Juta and Company Ltd, 2025) Mujuzi, Jamil Ddamulira
In East Asian Consortium BV v MTN Group Limited the applicant sued the respondent in a South African court for allegedly bribing Iranian officials to award the latter a tender at the expense of the former. The respondents invoked section 2 of the Foreign States Immunities Act, 1981, to argue that South African courts did not have jurisdiction over the matter because the action was indirectly against the Iranian government which enjoyed jurisdictional immunity under article 6(2)(b) of the Immunities Convention, 2004. The majority of the court declined to interpret section 2 of the Foreign States Immunities Act in light of article 6(2)(b) of the Immunities Convention. In reaching this conclusion, the court relied on the United Kingdom Supreme Court’s decision in Belhaj v Straw, which held that the drafting history of article 6(2)(b), as well as state practices, showed that it is not customary international law, and that in the United Kingdom the Immunities Convention was not regarded as international law. In this article, the author argues to the contrary. By undertaking an in-depth analysis of the drafting history of article 6(2)(b) of the Immunities Convention and current state practices, the author argues that article 6(2)(b) of the Immunities Convention is international law (as understood by the South African Constitutional Court). Consequently, the court should have relied on it in interpreting section 2 of the Foreign States Immunities Act. It is also argued that a combined reading of the drafting history of article 6(2)(b) of the Immunities Convention and section 2(2) of the Foreign States Immunities Act shows that the court should have held that it did not have jurisdiction in the case. It is argued, further, that article 6(2)(b) is not limited to cases where a foreign state has legal interest in property but that it is applicable to interests, rights, property and activities. Furthermore, since the alleged bribery took place in Iran and the acts in question were juri imperii, South African courts did not have jurisdiction.