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Local connectedness and connectedness im kleinen in the hyperspace of a metric space
(University of the Western Cape, 2026) Mavuso Qiniso
This work is a detailed study of the paper “Connectedness im kleinen and local connect-edness in 2 X and C(X)” by J. T. Goodykoontz, Jr. Our assumption throughout the study is that X is a compact connected metric space. We study the hyperspace 2 X, of all closed subsets of X, and C(X), the hyperspace of all connected elements of 2 X. The hyperspaces 2 X and C(X) are endowed with the Hausdorff metric topology and we show that the Haus-dorff metric topology is equivalent to the Vietoris topology. Our purpose is to study the connectivity properties of local connectedness and connectedness im kleinen on X and its hyperspaces. We show that for M ∈ C(X), 2 X is connected im kleinen at M if and only if for each open set U containing M there is a component of U which contains M in its interior. We also show that 2 X is locally connected at M if and only if for each open set U containing M there exists a connected open set V such that M ⊆ V ⊆ U. These two results are used to show the main results. For A ∈ 2 X, 2 X is locally connected (connected im kleinen) at A if and only if 2 X is locally connected (connected im kleinen) at each component of A. Finally, we prove the first two results of the paper “More on connectedness im kleinen and local connectedness in C(X)” by J. T. Goodykoontz, Jr. We show that for M ∈ C(X), 2 X connected im kleinen at M implies that C(X) is locally arcwise connected at M. The second results gives a characterisation of connectedness im kleinen in C(X).
Columnanidus calitzdorpensis ichnogen. ichnosp. nov: a new middle pleistocene subterranean termite trace fossil from South Africa
(John Wiley and Sons Ltd, 2026) Abrahams, Miengah; Muir, Robert A; Genise, Jorge F; Almond, John E; Hadebe, Gcinamahlubi; Hellstrom, John C; Jacobs, Rabia; Harris, Chris
Termites are landscape geo-engineers whose nesting activities substantially modify the physical and chemical properties of soils. Fossilised termite nests commonly constitute the only identifiable evidence of ancient termite activity and represent valuable trace fossil archives for reconstructing past environments. Here, we describe a new ichnogenus and ichnospecies, Columnanidus calitzdorpensis ichnogen. ichnosp. nov., from Quaternary alluvial deposits near Calitzdorp, South Africa. The subterranean nests are subcylindrical structures, reaching ~1 m in height and ~65 cm in diameter, and are characterised by a ~12 cm wide, shelved nest wall surrounding an empty central cavity. Within the nest wall, the gallery and chamber morphology and abundance vary between the inner and outer zones. The nests are preserved as calcretised features, composed of inter-laminations of clastic sediment and pedogenic carbonate precipitate. U-series dating of the carbonate laminations yields robust age peaks at 401 ± 46 ka and 323 ± 12 ka, indicating a Middle Pleistocene minimum age for nest formation. These ages coincide with intervals favourable for pedogenic carbonate development under semi-arid to arid climatic conditions. Hardpan calcretes capping the nests suggest prolonged periods of semi-arid conditions and sustained pedogenic stability during the Middle Pleistocene in the Calitzdorp region.
Improving secretion and stress tolerance in yeast strains engineered for consolidated bioprocessing with cell- surface adhered cellulase activities.
(University of the Western Cape, 2025) Hoffmeester, Lazzlo
The consolidated bioprocessing (CBP) of lignocellulosic biomass (LCB) has been established as a leading methodology for the production of alternative fuels and value-added products, since its conceptualisation in the early 2000s. Several studies have made advancements towards the development of a CBP organism capable of complete hydrolysis of cellulose and hemi-cellulose components of LCB and subsequent fermentation of monosaccharides producing maximum product yields. This can be achieved through the endowment of the yeast Saccharomyces cerevisiae with cellulolytic capabilities through the cell free or cell-attached production of fungal cellulases. However, CBP organisms must overcome the following major challenges: low cellulase secretion titres, low hydrolysis rates and varying susceptibility to inhibitory fermentation compounds and fermentation environment conditions, which often inhibit cell viability and metabolic processes. The employment of rational strain engineering technologies using gene targets related to various activities in the secretion pathway and stress response mechanisms of yeast has proven encouraging as many studies have reported improved cellulase secretion titres and improved strain robustness. Therefore, this study aimed to improve cellulase activity and strain robustness of two CBP engineered S. cerevisiae BY4741 strains producing a cell surface attached cellulase consortium (BGL, EG CBH1 and CBH2). This was achieved through the overexpression of PSE1, YHB1, and SED5 and measuring the effect on the heterologous cellulase activity, crystalline cellulose hydrolysis and stress tolerance of S. cerevisiae strains. One of the strains used in this study underwent further engineering through the CRISPR/Cas9-mediated deletion of two cell wall protein encoding genes, resulting in an increased cellulase carrying capacity. The results demonstrated that overexpression of native yeast genes yielded varying enhancements in individual cellulase activities which collectively translated to enhanced crystalline cellulose hydrolysis. In optimal conditions the most significant increases in individual cellulase activity were demonstrated with SED5 overexpression resulting in improved β-glucosidase (BGL) activity by 75%, cellobiohydrolase (CBH) activity by 180% and endoglucanase (EG) activity by 169% when compared to the respective background strains. This led to a crystalline cellulose hydrolysis improvement of 251% when compared the BYCC background strain. Furthermore, at elevated temperatures the most significant changes in individual cellulase activities were observed in BGL activity with an increase of 275% (PSE1 overexpression), CBH activity with a significant increase of 111% (SED5 overexpression) and EG activity with an improvement of 168% (PSE1 overexpression) when compared to respective background strains. Interestingly, the most significant increase in crystalline cellulose hydrolysis in elevated temperature was observed for the BY strain overexpressing SED5. Lastly, in weak acid stress, improvements were observed in BGL activity up to 52%, CBH activity up to 225% and EG activity up to 162% as facilitated by SED5 overexpression. This translated into a significant increase in crystalline cellulose hydrolysis of 366% when compared to the respective background strains. However, metabolic burden was observed when assessing stress tolerance and growth for the various strains with superior cellulase activities, which resulted in reduced tolerance towards stress factors and reduced growth rates. Overall, this study demonstrates the potential of rational engineering using the above-mentioned genes to improve cellulolytic performance of CBP engineered strains in both optimal and harsh conditions. However, careful consideration must be given to the metabolic impact of the enhancements introduced.
1D basin modelling of upper jurassic to upper cretaceous source rocks in the Southern Pletmos Sub-Basin, Outeniqua Basin, offshore South Africa
(John Wiley and Sons Inc, 2026) Agbor, Fritz Ako; Mhlambi, Sanelisiwe; Donker, Jan van Bever
The Pletmos sub-basin in the Outeniqua Basin, offshore South Africa, is divided by the Superior, Pletmos and Plettenberg faults into northern and southern depocentres. In this study, geological and organic geochemical data together with 1D basin modelling were used to investigate the burial, thermal and maturation histories, and the timing of hydrocarbon generation and expulsion of clay-rich source rocks in the southern depocentre. The modelled source rocks were of Kimmeridgian, Valanginian, Hauterivian, Aptian and Turonian ages. Source rock burial histories at the Ga-A4, Ga-E1, Ga-E2, Ga-H1, Ga-Q1 and Ga-Q2 wells in the Ga-A gas field were reconstructed with subsequent modelling of source rock thermal and maturation histories. The models were calibrated using vitrinite reflectance data from six offshore wells and constrained by palaeotemperature, heat flow and kinetic parameters. The modelling results indicate three principal phases of hydrocarbon generation (132–89, 89–45 and 45 Ma to present day), with a critical moment occurring at approximately 23 Ma during the Oligocene. The deepest syn-rift Kimmeridgian and Valanginian source rocks reached late-mature to over-mature conditions and are interpreted as the principal contributors to hydrocarbon charge in the basin. These results indicate that the petroleum system in the southern Pletmos sub-basin is predominantly gas-prone to gas-dominant, reflecting the advanced maturity of the deeper syn-rift source intervals and highlighting the continued exploration potential of deeply buried petroleum systems in the Outeniqua Basin
Project ODIN: advancing environmental genomic surveillance for public health across Sub-Saharan Africa
(Elsevier Ltd, 2026) Calvert-Joshua, Tracey; Levy, Joshua; Smith, Emily
Persistent SARS-CoV-2 transmission, ongoing mpox outbreaks, and the continued spread of endemic diseases such as typhoid fever and cholera underscore the urgent need for global, multiomics surveillance. In this Personal View, we present Project ODIN, a consortium of European and African partners launched in 2023 that aims to meet this challenge by deploying innovative systems for near real-time pathogen detection and actionable public health insights. The project is a collaboration between high-income and low-income countries in northern Europe and subSaharan Africa. Focusing on low-income and middle-income countries, ODIN integrates metagenomics with mobile laboratory systems for comprehensive pathogen monitoring across diverse environments. ODIN emphasises standardised sampling, bioinformatics pipelines, and data-sharing protocols to ensure reliable, interoperable results while addressing infrastructure and resource limitations. By bridging gaps in genomic surveillance, these initiatives seek to strengthen outbreak preparedness, improve pathogen detection, monitor antimicrobial resistance, and provide a holistic approach to One Health challenges. Together, these innovations could advance global surveillance capacity—particularly in under-resourced regions—paving the way for effective disease control and evidence-based policy making.