Medicinal plant cultivation | Tracing the source of water pollution

Comrades Marathon gets hotter

The Comrades Marathon, South Africa’s most iconic road running event, will be held on 28 August 2022 – much later in the year than the usual May/June date. Consequently, runners are more likely to experience heat-related illness along the route. The change in date prompted Havenga and colleagues to examine the likelihood of extreme heat events occurring on the new date using the Universal Thermal Comfort Index (UTCI). Although their analysis does not predict the weather for the 2022 date, they showed that UTCI values representing an intense heat stress response are historically more likely to occur in late August than in late May and early June. When athletes are exposed to warmer conditions, the body exhibits an adverse physiological response, decreasing performance and, in extreme cases, leading to heatstroke and hospitalisation. Hydration, clothing and pacing need to be adapted to the weather conditions on the day to reduce possible adverse physiological effects.

CSI Hartbeespoort: Fingerprinting sewage in water resources

The Hartbeespoort Reservoir in the Crocodile River catchment has suffered water pollution and invasive water hyacinth plants for decades. Upgrades to sewage works and sanitation in the Gauteng area hold the key to cleaning up the Crocodile River catchment.  High levels of nitrogen in water make the hyacinth grow at an “Olympic” pace and no attempt, whether chemical, biological or manual, will win the fight against this water weed. Diamond and Germishuys sampled these plants and analysed their nitrogen isotopes, confirming the view that overflowing sewage works and informal settlements with no toilets are the main source of pollution in this water. This technique is not new, but has likely never been used in Africa before, and so the potential exists to use plant or animal samples to trace the source of water pollution elsewhere.
Cultivation – a tool for conservation and commercialisation of medicinal plants
The worldwide trade in plant-based medicine increased from ZAR192 billion (USD30 billion) in 2000 to ZAR1.01 trillion (USD940 billion) in 2014. According to Mofokeng and colleagues, cultivation of medicinal plants provides several opportunities, including preservation of indigenous plants and related knowledge, access to primary health care through traditional medicine, local economic development, and job creation. Whereas unsustainable harvesting for income generation, land clearing for developments, and other human activities have led to the extinction of a number of medicinal plants, such as African ginger (Siphonichillus aethiopicus). Cultivation can improve biomass production for sustainable supply without negatively affecting the bioactivity or “power” of the medicinal plants. Over-supply of medicinal plant materials can negatively impact prices, and, therefore, cultivation needs to be managed in terms of market demand.
Building with bamboo in South Africa
Bamboo has potential as an environmentally friendly construction material in South Africa. Bamboo products such as floorboards are popular in South Africa, but using whole stems (culms) in bamboo construction is uncommon, even though bamboo is found in various parts of the country. Given the need for environmentally friendly construction materials and technologies, Ross and Alexander conducted literature-based research to determine the viability of whole-culm bamboo as a construction technology for South Africa. South Africa has one bamboo species considered suitable for construction – Bambusa balcooa – but the South African variety has not been evaluated in terms of its material properties. Engineering design approaches and material properties reported in the literature indicate that this species is a viable construction material. The limitations of bamboo design and construction are common to those countries where bamboo is used in construction. Their experience in overcoming these limitations can be transferred to South Africa, making bamboo construction a potentially viable construction technology for us.
Electrification of minibus taxis – running on fumes?
Electrification is expected to decarbonise transportation and forms part of the agenda to delay climate change. Electric vehicle sales have ballooned and production of combustion engines will stop soon. In sub-Saharan Africa the transition is slow. Crucial knowledge gaps, explored by Booysen and colleagues, include the potential demand and where and when this demand will occur. Minibus taxis carry more than 70% of commuters and little is known about their electrification requirements. Electrical demand planning is better with vehicle-based data than with passenger-based data. Stationary times provide ample time for taxis to recharge from the grid and solar, but using solar power requires substantial stationary battery capacity to negate grid-impacting fast charging.
Einstein, a supermassive black hole, and Africa
The Event Horizon Telescope (EHT) Collaboration recently released the first images of the supermassive black hole in the heart of the Milky Way galaxy. The ring size and shape in these images are consistent with Einstein’s general theory of relativity. The location of this black hole in southern skies and its rapidly changing appearance mean that expanding the EHT into Africa is critical to optimally utilise this unique gravitational laboratory in the future. Deane and Natarajan explain how leveraging our southern African geographic advantage will turn images into high-fidelity movies – a game-changing milestone for precision tests of gravity with the next-generation EHT. More equitable involvement of African countries and researchers in large-scale international scientific collaborations also has the potential to grow human capacity and technology development. Perhaps a deeper legacy of African EHT stations would be to spur further innovation, inspire local youths to excellence, and foster greater equality in science collaboration between the Global South and the rest of the world.