Academy of Science of South Africa (ASSAf): Open Journal Systems
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Pedestrian safety: Motorists’ attitudes to the law and driving practices in South Africa
No full textIn Africa, 40% of traffic fatalities are pedestrians – the highest proportion globally. Yet little is known about driver characteristics that are associated with unsafe driving in African countries. We aimed to explore associations between driving practices that endanger pedestrian safety and motorists’ attitudes to the law (i.e. lawlessness and normlessness), controlling for sociodemographic and personality factors. We used the Response Time Method, based on Russell Fazio’s attitude paradigm, to collect information about driver behaviours, attitudes, and personality traits among a sample of 440 motorists. Male gender was associated with unsafe driving, even when controlling for the effects of personality and attitudes to the law. Unsafe driving was also associated with four dimensions of motorists’ personality, namely aggression, impulsivity, risk tolerance, and altruism, even when controlling for sociodemographic factors. Lawlessness (defined as a general disregard for the law) is also an important determinant of unsafe driving, even when controlling for sociodemographic and personality factors. These findings suggest that efforts to improve pedestrian safety in South Africa should focus on changing motorists’ attitudes to the law.
Significance:
This study addresses pedestrian safety in the context of South Africa. The fact that 40% of traffic fatalities are pedestrians highlights the urgent need to understand the factors contributing to unsafe driving practices. The study delves into uncharted territory by examining driver characteristics associated with unsafe driving. Through exploring associations between driving practices that endanger pedestrian safety and motorists’ attitudes to the law, this article provides valuable insights that can inform targeted interventions
Microbiological growth analysis on a 275 kV transmission line composite insulator in South Africa
No full textTransmission line silicon rubber insulators are frequently subjected to harsh environmental conditions that can change their surface characteristics and result in a transient or permanent loss of hydrophobicity. Algae, fungi, mould, and lichen are examples of biological growth that can compromise the power system’s ability to operate safely by lowering the insulator’s flashover voltage. We evaluated and identified the major microorganisms that could be responsible for the flashovers of insulators in South Africa. Due to the difficulty of accessing insulators currently in use within the electricity network, only two insulators, from two provinces in South Africa, were used in the study. Although algae were not found on the insulators, two major filamentous fungi identified as Curvularia sp. and Aspergillus sp. were isolated. The absence of algae could be attributed to the weather pattern of the two locations where the insulators were placed during their use as part of the network. According to previous studies worldwide, the high occurrence of these fungi could be linked to the reduction of flashover voltage of the composite insulators. Although a larger survey including more insulators from all provinces in South Africa should be conducted, the current study demonstrates the need for a cleaning programme for insulators using cost-effective eco-friendly antimicrobial agents.
Significance:
Degradation and loss of hydrophobicity on the overhead line composite due to biological growth were found to be an impediment to the safe operation of high-voltage insulators. Fungi were found to be the main factor causing the degradation of overhead transmission lines.
With these data, a model can be developed to predict the rate of biological growth on a given insulator, to estimate the degradation of the surface conditions with time for the utility to know when to remove them from the line. Such a model could lead to a more reliable and efficient power system and reduce the engineer’s workload
The missing link in modern teaching? A review of Co-Teaching and Co-Research in Contexts of Inequality
No full textSue Nicolson (1950–2023): Internationally recognised insect physiologist and dedicated mentor
No full textAssessment of the spatiotemporal dynamics of the hydrological state of non-perennial river systems and identification of flow-contributing areas
No full textNon-perennial rivers (NPRs) have three hydrological states; each state has its importance, function and implication for water resource management. The dynamics of these states have been inadequately assessed and understood. Hence, this study sought to determine the spatiotemporal variations in the hydrological conditions of NPRs, focusing on the Touws River–Karoo drylands and Molototsi River within the semi-arid region of the Limpopo Province of South Africa. Additionally, the study aimed to delineate and characterize the primary areas contributing to runoff in these two river systems. Sentinel-1 and Sentinel-2 satellite data sources were employed in this study. Specifically, the modified normalized difference water index (MNDWI) derived from Sentinel-2 was utilized to delineate water surface areas along the two rivers. Subsequently, these derived datasets were utilized to assess the hydrological states over a 32-month period (2019–2022). Based on the presence of water, the river's state was classified as flowing, pooled, or dry. The results showed that remote sensing can be used to determine the hydrological state of the two river systems with ~90% overall accuracy. However, there is about a 30% chance that a flow event can be missed using Sentinel-2 due to clouds and temporal resolution. Some of these gaps can be filled using synthetic aperture radar (SAR) data (Sentinel-1), as demonstrated with the Molototsi River. In the Molototsi catchment, the upper catchment contributes the majority of flows. For the Touws River, the southwestern part of the catchment was determined as the major contributing area for the observed flows. This suggests that the chosen observation site might not be representative of upper catchment dynamics; therefore, a monitoring site in the upper catchment is required. This study provided hydrological information and an approach that can be used to monitor the hydrological states for better understanding and management of NPRs and catchments
Coagulation efficiency and removal mechanism for composite coagulant polyaluminium chloride/polydimethyldiallylammonium chloride in treating lightly micro-polluted raw water of Yangtze River in autumn
No full textThe effect of elevated carbon dioxide on the medicinal properties of Portulacaria afra
No full textThere is a global concern that rising atmospheric CO2 concentrations may impact the medicinal or nutritional properties of medicinal plants. Portulacaria afra is a South African medicinal plant that is used by traditional healers to treat various skin conditions. The aim of this study was to determine whether elevated CO2 concentrations would affect the medicinal properties of the leaves of P. afra. This was achieved by comparing the phytochemical presence, antioxidant and antimicrobial activity of the leaves of P. afra which were exposed to ambient (420 ppm) and elevated (600 ppm) CO2 concentrations of plants grown in greenhouse conditions. The results revealed that leaf samples that were exposed to elevated CO2 concentrations exhibited a significant increase in flavonoid presence, compared to the control group. The antioxidant activity of the leaves of P. afra (DPPH activity) remained mostly unchanged in the samples that were exposed to elevated CO2 concentrations. The antimicrobial activity efficacy against Cutibacterium acnes increased with increasing global atmospheric CO2 concentration. These findings suggest that P. afra is a resilient medicinal plant and that its leaves may continue to provide relief against certain ailments, despite rising atmospheric CO2 concentrations.
Significance:
Portulacaria afra is a South African medicinally important species that shows great resilience against elevated CO2 concentrations.
It is important to anticipate how changing environmental factors, such as rising CO2 concentrations, may affect natural resources.
The phytochemical profile and antioxidant and antimicrobial activities of the various plant parts either remained the same or increased after exposure to an elevated CO2 concentration of 600 ppm
Response to Simpson (2024): Standard heat stress indices may not be appropriate for assessing marathons
No full textDO MUNICIPALITIES HAVE THE POWER TO REGULATE THE KEEPING OF “DANGEROUS” DOGS?
No full textDog attacks and resultant deaths are frequent occurrences in South Africa. Pit bulls are responsible in many of these cases and there are calls for them to be banned. Dogs, however, are the property of their owners, and forcing people to give them up will amount to a deprivation of property and an infringement of a dog owner’s right to property, which is protected by section 25 of the Constitution. Dogfighting is rife in South Africa and the conduct of dog owners contributes to dogs being aggressive and leads to dog attacks. In terms of the Constitution, animal control is a functional area of concurrent national and provincial legislative competence; on a strict interpretation, this means that municipalities do not have the power to legislate on the function. However, everyone is guaranteed the right to freedom and security of the person, which includes the right to be free from all forms of violence from either public or private sources. As such, the municipality (as part of the State) must respect, protect, promote and fulfil the right. Municipalities also have a duty to promote a safe and healthy environment, and the power to make by-laws on matters they may administer. They may also exercise powers that are reasonable and incidental to the effective performance of municipal functions, which is supported by the principle of subsidiarity, the fulfilment of the duties arising from section 12 of the Constitution, and the objective to promote a safe and healthy environment. A municipality that has the necessary resources can legislate and enforce by-laws on matters listed in Schedule 4A and 5A of the Constitution, provided that such action seeks to further the objectives of Chapter 2 of the Constitution and is not in conflict with measures adopted by the national and provincial spheres. The National Society for the Prevention of Cruelty to Animals (NSPCA) is responsible for animal welfare, but the responsibilities of animal welfare organisations are becoming greater as urbanisation in South Africa accelerates and animals in many disadvantaged communities are in dire need of basic animal care. The suite of local government law is geared towards the social and economic upliftment of communities, and there is legislative justification for interventions by municipalities to address matters such as the control of public nuisances, dog licensing, the operation of pounds, and the conduct of community members that can alleviate the pressure on those organisations tasked with animal care. There are a number of legislative instruments that apply to animals. A consolidation of the provisions of the various pieces of legislation into a single by-law aimed at regulating the keeping and treatment of dogs, may result in increased law enforcement and (it is hoped) increased sentences as a result of amplified enforcement, as well as improved deterrence