Academy of Science of South Africa (ASSAf): Open Journal Systems
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DISTINGUISHING THE FORMS OF COMMON PURPOSE LIABILITY S v Govender 2023 (2) SACR 137 (SCA)
No full textIn the case of S v Govender (2023 (2) SACR 137 (SCA)), the Supreme Court of Appeal (SCA) was required once again to examine the common purpose doctrine, which although it has been in use in South African law for the past century, has in recent years seen significant development, in its expansion from being applied solely to a prior agreement, to also being applied in the case of an active association between two or more persons. The importance of distinguishing between these different forms of the common purpose doctrine has concomitantly also become increasingly important.As the court points out in S v Mzwempi (2011 (2) SACR 237 (ECM) par 56), prior-agreement common purpose encompasses “any conduct which falls within the wide and general common design”, whereas active-association common purpose is “restricted to particular conduct”. Thus, in active-association common purpose, the association is with a “specific act” by which the crime was committed by another participant in the common purpose. It follows that, given the “marked differences” between the two forms of common purpose:“in a case where the state seeks to place reliance on the doctrine of common purpose, the trier of fact will be required to determine the nature of the common purpose relied upon, what the scope of that common purpose happened to be, and whether the accused was a participant, and remained a participant, in the common purpose.”The discussion examines the significance of the distinction between the different forms of common purpose doctrine, in light of the SCA judgment in the case of Govender
A new high-resolution geomagnetic field model for southern Africa
No full textEarth’s magnetic field is a dynamic, changing phenomenon. The geomagnetic field consists of contributions from several sources, of which the main field originating in Earth’s core makes up the bulk. On regional and local scales at Earth’s surface, the lithospheric field can make a substantial contribution to the overall field and therefore needs to be considered in field models. A locally derived regional core field model, named HMOREG, has been shown to give accurate predictions of the southern African region. In this study, a new regional field model called the South African Regional Core and Crust model (SARCC) is introduced. This is the first time that a local lithospheric model, estimated by employing the revised spherical cap harmonic analysis modelling method, has been combined with the core component of CHAOS-6, a global field model. It is compared here with the existing regional field model as well as with global core field models. The SARCC model shows small-scale variations that are not present in the other three models. Including a lithospheric magnetic field component likely contributed to the better performance of the SARCC model when compared to other global and local field models. The SARCC model showed a 33% reduction in error compared to surface observations obtained from field surveys and INTERMAGNET stations in the Y component, and HMOREG showed a 7% reduction in error compared to the global field models. The new model can easily be updated with global geomagnetic models that incorporate the most recent, state-of-the-art core and magnetospheric field models.
Significance:
Earth’s magnetic field is an integral part of many current navigational methods in use. Updates of geomagnetic field models are required to ensure the accuracy of maps, navigation, and positioning information. The SARCC regional geomagnetic field model introduced here was compared with global geomagnetic field models, and the inclusion of a lithospheric magnetic field component likely contributed to the better performance of the SARCC model. This regional model of southern Africa could easily be updated on a regular basis, and used for high-resolution information on the Earth’s magnetic field for the wider scientific community
Comparative study: Garlic, ginger and turmeric as natural antimicrobials and bioactives
No full textBiologically active compounds in most spices possess antimicrobial and other important biomedical properties. There have been huge demands for natural immunity boosters (spices and herbs), considering the recent global pandemic and challenges relating to drug-resistant pathogens. This study was designed to compare the efficacy of ginger, garlic and turmeric spices against some pathogenic microorganisms. Aqueous extraction of spices, antimicrobial sensitivity and minimum inhibitory concentration tests were done using standard microbiological methods. Bioactive compounds were estimated using the gas chromatography–mass spectrometry (GC-MS) method. Aqueous extracts of ginger inhibited the growth of all test isolates except Streptococcus pneumoniae, with inhibition zones ranging between 0.9 mm and 13.5 mm. Escherichia coli, S. pneumoniae and Haemophilus influenzae were resistant to turmeric extracts, while the extract of garlic inhibited only four of the test pathogens. Inhibition zones for turmeric ranged between 4.4 mm and 10.9 mm, while those for garlic were between 4.7 mm and 11.5 mm. All the spice extracts did not inhibit microbial growth at 10–40%. An antibiotic spectrum indicated that Bacillus sp. was resistant to all but one, nitrofurantoin, which also inhibited the growth of almost all pathogens, except H. influenzae, with zones ranging between 10.5 mm and 11.6 mm. All test pathogens were resistant to cloxacillin except E. coli (10.6 mm). The major phyto-active compounds present in ginger are 2-Butanone,4-(4-hydroxy-3-methoxyphenyl), 1,3-Cyclohexadiene and 1-(4-Hydroxy-3-methoxyphenyl).
Significance:
Conclusively, ginger, turmeric and garlic have varied inhibitory activities against diverse organisms, indicating their antimicrobial properties; however, ginger showed a higher inhibitory effect and more diverse antimicrobial property amongst selected isolates. Furthermore, certain bioactive compounds of biomedical importance were present. We therefore recommend the use of these spices as alternative natural food preservatives against spoilage organisms, as well as potential natural sources for bioactive compounds in drug development against pathogens
The power of contemporary African DNA: Exploring models of human evolution and health in Africa
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Seepage behaviour through earth dams with zones of different filling materials
No full textSince more than one-third of dam failures have been attributed to uncontrolled seepage, it is of great importance to investigate the behaviour of this phenomenon in order to achieve the maximum degree of safety for such dams. The present work investigated the influence of the permeability coefficient of the different materials used in zoned earth dams on different seepage parameters. For the modelling and analysis processes, the Seep/w and Seep2D software were employed. The numerical results prove that the optimum relative hydraulic conductivity between the inner and transition shells is about 0.001, and it is better to use filling materials with less hydraulic conductivity in the upstream transition and outer shells than in the downstream ones. A good agreement was noted between the obtained results from Seep/w and those from Seep2D. Reducing the hydraulic conductivity of both the upstream and the downstream shells, or of the downstream shells only, causes the pore water pressure in the dam body to increase significantly, and causes a remarkable reduction in the seeped water quantity and velocity. A moderate reduction in the different seepage parameters is achieved by reducing the hydraulic conductivity of the upstream transition shell, and a small reduction is noticed by reducing the hydraulic conductivity of the upstream outer shell
Reflecting on Evictions and Unlawful Occupation of Land in South Africa: Where Do Some Gaps Still Remain?
No full textThe issue of unlawful occupation and homelessness has been a very prominent topic for many decades. While our approach to evictions and unlawful occupation has clearly shifted from a draconian approach under the Prevention of Illegal Squatting Act 51 of 1951 (hereafter PISA) to an approach that focusses on human rights under the Prevention of Illegal Eviction from and Unlawful Occupation of Land Act 19 of 1998 (hereafter PIE), there are still various aspects that potentially fall short in protecting the rights of the various stakeholders involved in these disputes. In particular, this paper focusses on three areas where PIE potentially falls short. In this regard we examine cases of the impossibility of eviction orders, our current understanding of the notion of "home", and whether or not PIE applies to both occupied and unoccupied structures. We also briefly explore issues relating to the non-implementation of PIE, especially in relation to the government's goal of preventing unlawful occupation. Central to these discussions is whether our current approach is sufficient and in line with constitutional obligations or whether we need to rethink our approaches to ensure that we do not undo the progress made since apartheid
Comparing cardiorespiratory fitness and physical activity levels between third- and fifth-year medical students in a South African university
Full text linkBackground: Cardiovascular disease (CVD) risk factors such as sedentary behaviour, decreased physical activity (PA), and low cardiorespiratory fitness lead to an increased and accelerated risk of cardiovascular disease and mortality. Medical students tend to adopt sedentary lifestyles due to a demanding curriculum. This may have a negative effect on CVD risk factors and cardiorespiratory fitness levels of medical students.
Objectives: To compare physical activity and cardiorespiratory fitness levels in a cohort of third- and fifth-year undergraduate medical students in a South African university.
Methods: Data from 123 third-year and 139 fifth-year medical students in the Graduate Entry Medical Programme (GEMP) at the Faculty of Health Sciences, University of the Witwatersrand, were collected. Measurements included CVD risk factors, height, weight, blood pressure, waist circumference, cardiorespiratory fitness, physical activity vital signs and pre-participation health screening questionnaires. Descriptive statistics were presented as mean ± standard deviation or median [interquartile range] depending whether the data were normally distributed or not.
Results: Both groups had low cardiorespiratory fitness when compared to norm values (GEMPI VO2 peak was 29.1 ± 5.9 ml.kg-1.min-1 and GEMPIII VO2 peak was 30.0[11.0] ml.kg-1.min-1). Most participants did not meet WHO physical activity requirements (GEMP I: 72%; GEMP III: 78%). There were significant differences in BMI (p=0.046), diastolic blood pressure (p=0.034) and VO2 peak (p=0.00001) between students meeting and not meeting WHO physical activity requirements (p<0.05).
Conclusion: Third- and fifth-year medical students at a South African university fail to meet recommended WHO physical activity levels and are below cardiorespiratory fitness norms. Therefore, medical institutions should promote and implement targeted physical activity interventions to reduce the prevalence of low fitness levels and the associated health hazards among their students
Navigating the AI Innovation: A Publisher's Balancing Act with Fundamental Principles
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The Role of Public Policy in King v De Jager (CCT 315/18) [2021] ZACC 4 (19 February 2021)
No full textIn King v De Jager (CCT 315/18) [2021] ZACC 4 (19 February 2021), the Constitutional Court considered whether a discriminatory out-and-out disinheritance clause in a private will could be declared unenforceable in terms of public policy. This opened private wills with disinheritance clauses to the scrutinising evaluation of public values despite freedom of testation. Although public policy has always been an elusive concept, South African public policy is infused with constitutional values to give more clarity on the content of public policy. In King a conflation emerged between constitutional rights, legislative violations and public policy values, however. The court grappled with the question of whether to apply the Constitution directly based on a violation in terms of section 9(4) or whether the section 8 of the Equality Act should be applied directly through the subsidiarity principle, or whether the discriminatory clause should be evaluated through the public policy lens. Where the conflicting values were weighed up there seem to be hints of subjective views to tip the scales in favour of one value over another. This is a concern when public policy is used to advance a subjective view of what the community values more, especially when it involves the disruption of the devolvement of a deceased's estate. This underlines the difficult application of public policy values, even in a constitutional democracy, when competing values are at play