Scielo RSS <![CDATA[South African Journal of Science]]> vol. 112 num. 3-4 lang. es <![CDATA[SciELO Logo]]> <![CDATA[<b>What really matters for students in South African higher education?</b>]]> <![CDATA[<b>'No man is an island, entire of itself...'</b>]]> <![CDATA[<b>Secret society, secret sources?</b>]]> <![CDATA[<b>Complexities and contradictions of doctoral education in South Africa</b>]]> <![CDATA[<b>Producing the next generation of water resource experts in South Africa</b>]]> <![CDATA[<b>The essence of scholarship: Charting a path through the thickets of scholarly publishing</b>]]> <![CDATA[<b>For sustainable funding and fees, the undergraduate system in South Africa must be restructured</b>]]> <![CDATA[<b>A review of the lunar laser ranging technique and contribution of timing systems</b>]]> The lunar laser ranging (LLR) technique is based on the two-way time-of-flight of laser pulses from an earth station to the retroreflectors that are located on the surface of the moon. We discuss the ranging technique and contribution of the timing systems and its significance in light of the new LLR station currently under development by the Hartebeesthoek Radio Astronomy Observatory (HartRAO). Firstly, developing the LLR station at HartRAO is an initiative that will improve the current geometrical network of the LLR stations which are presently concentrated in the northern hemisphere. Secondly, data products derived from the LLR experiments - such as accurate lunar orbit, tests of the general relativity theory, earth-moon dynamics, interior structure of the moon, reference frames, and station position and velocities - are important in better understanding the earth-moon system. We highlight factors affecting the measured range such as the effect of earth tides on station position and delays induced by timing systems, as these must be taken into account during the development of the LLR analysis software. HartRAO is collocated with other fundamental space geodetic techniques which makes it a true fiducial geodetic site in the southern hemisphere and a central point for further development of space-based techniques in Africa. Furthermore, the new LLR will complement the existing techniques by providing new niche areas of research both in Africa and internationally. <![CDATA[<b>Tuberculous meningitis in infants and children: Insights from nuclear magnetic resonance metabolomics</b>]]> Tuberculous meningitis (TBM) is a prevalent form of central nervous system tuberculosis (CNS-TB) and the most severe common form of bacterial meningitis in infants and children below the age of 13 years, especially in the Western Cape Province of South Africa. Research to identify markers for timely and accurate diagnosis and treatment outcomes remains high on the agenda for TBM, in respect of which the field of metabolomics is as yet largely unexploited. However, the national Department of Science and Technology (DST) recently established several biotechnology platforms at South African institutions, including one for metabolomics hosted at North-West University. We introduce this national platform for nuclear magnetic resonance (NMR) metabolomics by providing an overview of work on TBM. We focus on selected collaborative multidisciplinary approaches to this disease and conclude with the outcomes of an untargeted NMR metabolomics study of cerebrospinal fluid from TBM patients. This study enabled the formulation of a conceptual shuttle representing the unique metabolic plasticity of CNS metabolism towards the energy requirements for the microglia-driven neuroinflammatory responses, of which TBM is one example. From insights generated by this explorative NMR metabolomics investigation, we propose directions for future in-depth research strategies to address this devastating disease. In our view, the timely initiative of the DST, the operational expertise in metabolomics now available and the potential for involving national and international networks in this field of research offers remarkable opportunities for the future of metabolomics in South Africa and for an ever greater understanding of disease mechanisms. <![CDATA[<b>Enhancing climate governance through indigenous knowledge: Case in sustainability science</b>]]> The current tempo of climate change strategies puts the notion of sustainability in question. In this philosophy, mitigation and adaptation strategies ought to be appropriate to the sectors and communities that are targeted. There is a growing realisation that the effectiveness of both strategies hinges on climate governance, which also informs their sustainability. The application of the climate governance concept by the technocratic divide (policymakers and climate practitioners) to communities facing climate change impacts, however, is still a poorly developed field, despite extensive treatment by academia. By drawing heavily from conceptual and analytical review of scholarship on the utility of indigenous knowledge (IK) in climate science, these authors argue that IK can be deployed in the practice of climate governance. It reveals that the merits of such a deployment lie in the understanding that the tenets of IK and climate governance overlap and are complementary. This is exhibited by examining the conceptual, empirical and sustainability strands of the climate governance-IK nexus. In the milieu of climate change problems, it is argued that the basic elements of climate governance, where actions are informed by the principles of decentralisation and autonomy; accountability and transparency; responsiveness and flexibility; and participation and inclusion, can be pragmatic particularly to communities who have been religiously observing changes in their environment. Therefore, it becomes necessary to invigorate the participation of communities, with their IK, in designing climate change interventions, which in this view can be a means to attain the objectives of climate governance. <![CDATA[<b>Use and usefulness of measures of marine endemicity in South Africa</b>]]> Numerous authors have cited numbers, or proportions, of endemic species within South(ern) African marine taxa, but comparisons between these statistics are confounded by differing definitions of regional boundaries and differences among data sets analysed. These have resulted in considerable variations in published endemicity data, even within the same taxonomic group. We tabulated and compared key endemicity statistics for regional marine taxa and explained biases in the data sets. The most comprehensive data sets available give overall marine endemicity within the national boundaries of South Africa as 28-33%, but estimates within individual taxa making up these totals vary enormously, from 0% (Aves, Mammalia) to over 90% (Polyplacophora). We also examined published data documenting localised endemicity patterns around the coastline. These consistently show the highest numbers of endemics occurring along the South Coast. There are logical biogeographical reasons to expect this trend, but endemicity rates are also inherently biased by distance from defined political boundaries and by differing sampling effort locally and in neighbouring countries. Range restriction is considered a better measure of conservation status than endemicity, although it is far less often used and yields very different patterns. Properly and consistently calculated measures of national endemicity do, however, retain significant conservation value, and the rates for South African marine biota are high relative to other regions globally, being exceeded only by New Zealand and Antarctica. It is important that when citing endemicity statistics, researchers and conservation managers understand the definitions used and the many constraints under which these measures are derived. <![CDATA[<b>Treatment technology for brewery wastewater in a water-scarce country: A review</b>]]> Water is a scarce resource in many parts of the world; consequently the application of innovative strategies to treat wastewater for reuse is a priority. The brewery industry is one of the largest industrial users of water, but its effluent is characterised by high levels of organic contaminants which require remediation before reuse. Various conventional treatment methods such as anaerobic and aerobic systems, which are effective options because of their high removal efficiencies, are discussed in this study. Other methods such as membrane based technologies, carbon nanotubes, activated carbon, electrochemical methods, algal ponds and constructed wetlands are also analysed. Their efficiency as well as advantages and disadvantages are highlighted and evaluated. Combinations of various treatment processes to improve the quality of the final effluent are discussed. <![CDATA[<b>Fertigation of <i>Brassica rapa </i>L. using treated landfill leachate as a nutrient recycling option</b>]]> Optimising nutrient availability and minimising plant metal contamination are vital in sustainable agriculture. This paper reports experiments in which treated leachate was used at different concentrations with predetermined N content for fertigation of Brassica rapa L. (leafy vegetable). An inorganic fertiliser, with N content equivalent to the leachate amount, was also prepared, as well as a control. Growth (leaf length, leaf width and stem height), harvest parameters (total number of leaves, root length and root dry weight) and specific growth rates (mm/day) were determined for three consecutive seasons. The dry weights of leaves, roots and stems in the leachate treatments were within the ranges of 1.95-3.60 g, 1.18-3.60 g and 0.33-1.37 g, with biomasses of 1.75 g, 1.14 g and 0.2 g, respectively, which were higher than those of the control. B. rapa L fertigated with 25% diluted treated leachate recorded high specific growth rate and a leaf length of 0.53 mm/day and 0.23.17±0.58 cm, respectively (%N=0.023; p<0.05). The maximum permissible mineral concentration set by the Food and Agricultural Organization of the United Nations/World Health Organization (FAO/WHO) was compared with that of the grown plants. Treated leachate can increase plant nutrient content. <![CDATA[<b>Recent trends in the climate of Namaqualand, a megadiverse arid region of South Africa</b>]]> Namaqualand is especially vulnerable to future climate change impacts. Using a high-resolution (0.5°x0.5°) gridded data set (CRU TS 3.1) and individual weather station data, we demonstrated that temperatures as well as frequency of hot extremes have increased across this region. Specifically, minimum temperatures have increased by 1.4 °C and maximum temperatures by 1.1 °C over the last century. Of the five weather stations analysed, two showed evidence of a significant increase in the duration of warm spells of up to 5 days per decade and a reduction in the number of cool days (TX10P) by up to 3 days per decade. In terms of rainfall, we found no clear evidence for a significant change in annual totals or the frequency or intensity of rainfall events. Seasonal trends in rainfall did, however, demonstrate some spatial variability across the region. Spatial trends in evapotranspiration obtained from the 8-day MOD16 ET product were characterised by a steepening inland-coastal gradient where areas along the coastline showed a significant increase in evapotranspiration of up to 30 mm per decade, most notably in spring and summer. The increase in temperature linked with the increases in evapotranspiration pose significant challenges for water availability in the region, but further research into changes in coastal fog is required in order for a more reliable assessment to be made. Overall, the results presented in this study provide evidence-based information for the management of climate change impacts as well as the development of appropriate adaptation responses at a local scale. <![CDATA[<b>Angolan vegetable crops have unique genotypes of potential value for future breeding programmes</b>]]> A survey was carried out in Angola with the aim of collecting vegetable crops. Collecting expeditions were conducted in Kwanza-Sul, Benguela, Huíla and Namibe Provinces and a total of 80 accessions belonging to 22 species was collected from farmers and local markets. Species belonging to the Solanaceae (37 accessions) and Cucurbitaceae (36 accessions) families were the most frequently found with pepper and eggplant being the predominant solanaceous crops collected. Peppers were sold in local markets as a mixture of different types, even different species: Capsicum chinense, C. baccatum, C. frutescens and C. pubescens. Most of the eggplant accessions collected belonged to Solanum aethiopicum L. Gilo Group, the so-called 'scarlet eggplant'. Cucurbita genus was better represented than the other cucurbit crops. A high morphological variation was present in the Cucurbita maxima and C. moschata accessions. A set of 22 Cucurbita accessions from Angola, along with 32 Cucurbita controls from a wide range of origins, was cultivated in Valencia, Spain and characterised based on morphology and molecularity using a set of 15 microsatellite markers. A strong dependence on latitude was found in most of the accessions and as a result, many accessions did not set fruit. The molecular analysis showed high molecular variability and uniqueness in the collected accessions, as shown by their segregation from the set of global controls. In summary, the material collected is quite valuable because of its uniqueness and the potential of the breeding characteristics it possesses. <![CDATA[<b>Antimutagenic and antioxidant effects of a South African traditional formulation used as an immune booster</b>]]> The traditional medicines sector in South Africa is still largely unregulated despite legislation aimed at regulating the practice being in place. The HIV and AIDS epidemic has fuelled demand for traditional medicines, with many patients consulting traditional health practitioners who offer different treatments, including herbal immune boosters. This study investigated the mutagenic and antioxidant effects of the widely sold herbal immune booster, uMakhonya®. The Ames test was used for analysis of the genototoxic effects while the adenosine triphosphate (ATP) assay was used to evaluate cell cytotoxicity in peripheral blood mononuclear cells (PBMCs) and THP-1 monocytes. To evaluate the antioxidant effects the malondialdehyde (MDA) quantification, the nitric oxide and 1,1-diphenyl-2-picryl-hydrazyl (DPPH) assays were used. UMakhonya® doses of up to 5000 μg/mL were not genotoxic in the Ames test. UMakhonya® was shown to induce dose-dependent cytotoxicity in both PBMCs and THP-1 cells with doses ranging from 500 μg/ mL to 1000 μg/mL, showing significant (p<0.05) toxicity. UMakhonya® was able to significantly (p<0.05) reduce nitrite radicals at 100 μg/mL while lower doses were not effective when compared to samples stimulated by lipopolysaccharide only. Non-cytotoxic doses of uMakhonya® showed significant (p<0.05) lipid peroxide scavenging ability in supernatants while this scavenging ability was considerably reduced intracellularly. In the DPPH assay, when both uMakhonya®and ascorbic acid were reconstituted in buffered saline, the traditional herbal remedy showed better radical scavenging abilities. Therefore further studies on the genotoxicity of uMakhonya®, when metabolically activated, and its antioxidant effects in in-vivo models are warranted. <![CDATA[<b>A bibliometric analysis of research on Ebola in Science Citation Index Expanded</b>]]> An unprecedented outbreak of the Ebola virus in 2014 claimed more than 1000 lives in West Africa and the World Health Organization declared a global public health emergency. This outbreak will undoubtedly promote additional research related to the Ebola virus and will create debate related to experimental drugs. This article identified the quantum of research in the field since 1991; the scientific disciplines that contributed to the field; the countries, organisations and authors that supported such research and the most cited articles. An increasing trend in annual production during 1991-2013 was observed. Journal of Virology, Journal of Infectious Diseases, and Virology were the three most productive journals in the field. Similarly, the field of virology dominated the 73 categories in which the Ebola research was classified. A total of 63 countries contributed to Ebola-related research, led by the USA. The most productive institutions were the United States Army Medical Research Institute of Infectious Diseases, the Centers for Disease Control and Prevention, and the National Institute of Allergy and Infectious Diseases. African countries were more likely to be involved in international collaboration than independent research. The most influential article exhibited a notable citation pattern and presented global trends in emerging infectious diseases. <![CDATA[<b>The evolving landscape of plant breeders' rights regarding wheat varieties in South Africa</b>]]> Addressing the multiple challenges facing global agriculture requires integrated innovation in areas such as seeds, biotechnology, crop protection, grain storage and transport. Innovations related to plant improvement and the development of new or improved plant varieties will only happen at an optimal level if plant breeders' rights (PBR) are properly protected. The objective was to analyse the evolving landscape of wheat plant breeders' rights to address the dearth of empirical evidence of the patterns and trends of wheat varietal improvements in South Africa. We compiled a detailed and novel count and attribute database of wheat varietal innovations in South Africa from 1979 to 2013 using various sources. This data set was then analysed to ascertain the main trends in, and ownership of PBRs for wheat varietal improvements in South Africa over this period. A total of 134 PBR wheat varietal innovations were lodged from 1979 to 2013, an average of 6 applications per year. The administrative delays in granting PBR applications were substantially reduced by 77 days during the post-deregulation period (after 1996), indicating increased efficiency. The main PBR applicants were Sensako (39%), the Agricultural Research Council Small Grains Institute (ARC-SGI) (25%) and Pannar (15%). The ARC-SGI contributed to some of the PBRs owned by private companies through shared genetic resources before Plant Variety Protection (PVP) was implemented. Future innovations and dissemination of wheat innovations can be stimulated by plant variety protection, together with broader variety sector legislation that encourages both public and private sector investment. <![CDATA[<b>Trading on extinction: An open-access deterrence model for the South African abalone fishery</b>]]> South African rhinoceros (e.g. Diceros bicornis) and abalone (Haliotis midae) have in common that they both are harvested under open-access conditions, are high-value commodities and are traded illegally. The difference is that a legal market for abalone already exists. An open-access deterrence model was developed for South African abalone, using Table Mountain National Park as a case study. It was found that illegal poaching spiked following the closure of the recreational fishery. The resource custodian's objective is to maximise returns from confiscations. This study showed that a legal trade results in a 'trading on extinction' resource trap, with a race for profits, an increase in the probability of detection after a poaching event and the depletion of populations. In contrast with HS Gordon's seminal article (J Polit Econ 1954;62:124-142), profit maximisation does not automatically improve the sustainability of the resource. Under certain conditions (e.g. a legal trade with costly enforcement), profit maximisation may actually deplete abalone populations. The article also has implications for rhino populations, as a legal trade is currently proposed. <![CDATA[<b>AutoCal: A software application for calibrating photometric data</b>]]> We present a software application for the calibration of stellar magnitudes in the absence of standard stars. It uses an existing algorithm to match stars in the target's field of view to catalogue entries and computes the average offset between the two sets of magnitudes using a weighted least-squares approach. This offset is used to calibrate the target's instrumental magnitude. The software application was used to calibrate magnitudes for six Be/X-ray binary sources in the Small Magellanic Cloud and the results were compared with published results for these sources. Where comparisons were possible, our results agreed with those results within the uncertainties specified. Infrared variability was found for all six of the sources tested. The interactive outlier removal that was made possible by our software allowed for smaller uncertainties to be reported for our results. <![CDATA[<b>Changing boundaries: Overcoming modifiable areal unit problems related to unemployment data in South Africa</b>]]> The longitudinal comparison of census data in spatial format is often problematic because of changes in administrative boundaries. Such shifting boundaries are referred to as the modifiable areal unit problem (MAUP). This article utilises unemployment data between 1991 and 2007 in South Africa to illustrate the challenge and proposes ways to overcome it. Various censuses in South Africa use different reporting geographies. Unemployment data for magisterial districts of census 1991 and 1996 were re-modelled to the 2005 municipal boundaries. This article showed that areal interpolation to a common administrative boundary could overcome these reporting obstacles. The results confirmed more accurate interpolations in rural areas with standard errors below 3300. Conversely, the largest errors were recorded in the metropolitan areas. Huge increases in unemployment between 1996 and 2001 statistics were also evident, especially in the metropolitan areas. Although such areas are more complex in nature, making it more difficult to accurately calculate census data, the increase in unemployment could also be the result of census taking methods. The article concludes that socio-economic data should be available at the smallest possible geographic area to ensure more accurate results in interpolation. It also recommends that new output areas be conceptualised to create a seamless database of census data from 1991 to 2011 in South Africa. <![CDATA[<b>Dental microwear differences between eastern and southern African fossil bovids and hominins</b>]]> Dental microwear has proven to be a valuable tool for reconstructing diets of fossil vertebrates. However, recent studies have suggested that the pattern of microscopic scratches and pits on teeth may be more reflective of environmental grit than of food preferences. Could differences in dental microwear between early hominins, for example, therefore be a result of dust level rather than of diet? We investigated this possibility using a palaeocommunity approach. We compared microwear texture differences between eastern and southern African Hominini, along with Plio-Pleistocene specimens representing two tribes of bovids, Alcelaphini and Antilopini, from the same deposits as the early hominins. If exogenous grit swamps diet signals, we would expect community-wide microwear patterns separating samples by region. Results indicate that each of the three tribes shows a different pattern of variation of microwear textures between eastern and southern Africa. These results imply that differences in microwear reflect diet rather than grit load, and that microwear can provide valuable information not just about environmental dust level, but about food preferences of fossil vertebrates.