Scielo RSS <![CDATA[South African Journal of Science]]> vol. 110 num. 11-12 lang. en <![CDATA[SciELO Logo]]> <![CDATA[<b>Science and education as antidotes</b>]]> <![CDATA[<b>Documenting a lost ecosystem</b>]]> <![CDATA[<b>Rough and tumble</b>]]> <![CDATA[<b>The University of East Africa: Anatomy of a failed experiment?</b>]]> <![CDATA[<b>Number theory and the unity of science</b>]]> <![CDATA[<b>Realising the value of continuous monitoring programmes for biodiversity conservation</b>]]> <![CDATA[<b>A symbiotic glance at the complexities of signature microbiomic interventions: Infusing balance</b>]]> <![CDATA[<b>Industry-directed training and research programmes: The BMI experience</b>]]> Universities are academic institutions with the primary objectives of teaching students a particular academic discipline and for conducting research related to that discipline. Traditionally, very little collaboration existed between universities and industry with respect to training and research in the mathematical sciences. Because of funding pressure, more and more universities are forced to find external sources of income. In this paper, we discuss a framework for designing and implementing career-oriented training programmes and industry-directed research programmes with a statistical science core. This framework was used as the basis for designing and implementing a highly successful training and research programme at North-West University's Centre for Business Mathematics and Informatics. (Centre for BMI), with the active support of industry partners Absa and SAS Institute. We believe that the lessons learnt from its implementation could form valuable guidelines for other, similar initiatives. <![CDATA[<b>Pollination ecosystem services in South African agricultural systems</b>]]> Insect pollinators, both managed and wild, have become a focus of global scientific, political and media attention because of their apparent decline and the perceived impact of this decline on crop production. Crop pollination by insects is an essential ecosystem service that increases the yield and quality of approximately 35% of crops worldwide. Pollinator declines are a consequence of multiple environmental pressures, e.g. habitat transformation and fragmentation, loss of floral resources, pesticides, pests and diseases, and climate change. Similar environmental pressures are faced in South Africa where there is a high demand for pollination services. In this paper, we synthesise data on the importance of different pollinators as a basis for services to South African crops and on the status of managed honeybees. We also focus on insect pollination services for the Western Cape deciduous fruit industry, which is worth ZAR9800 million per year and is heavily reliant on pollination services from managed honeybees. We discuss landscape and regional level floral resources needed to maintain sufficient numbers of managed honeybee colonies. In summary, the available literature shows a lack of data on diversity and abundance of crop pollinators, and a lack of longterm data to assess declines. We highlight key areas that require research in South Africa and emphasise the critical role of floral resource availability at the landscape and regional scale to sustain pollinators. We conclude that understanding the dynamics of how floral resources are used will help inform how landscapes could be better managed in order to provide long-term sustainable pollination services. <![CDATA[<b>Early planting and hand sorting effectively controls seed-borne fungi in farm-retained bean seed</b>]]> Home-saved bean (Phaseolus vulgaris L.) seed can be hand-sorted to remove discoloured seed, thereby reducing the level of contamination by certain seed-borne fungi and improving seed germination. In this study, the effect of planting date on the infection and discolouration of bean seed by seed-borne fungi was investigated in order to improve the quality of hand-sorted, farm-retained bean seeds used by resource poor smallholder farmers. The germination quality and level of seed-borne fungi in hand-sorted first-generation bean seed harvested from an early-, mid- and late-summer season planted crop was therefore assessed. The highest percentage of discoloured seed (68%) was obtained from the mid-summer season planting. Non-discoloured seed from early- and late-season plantings had significantly (o<0.001) higher normal germination (82% and 77%, respectively) than that from the mid-season planting date (58%). Irrespective of planting date, unsorted seed and discoloured seed had higher levels of infection by Fusarium spp. and Phaeoisariopsis spp. than the non-discoloured seed. Removal of discoloured seed by hand sorting eliminated Rhizoctonia spp. from all seed lots. Farmers can eliminate this pathogen by simply removing discoloured seed. Non-discoloured seed from the early-planted crop had the lowest level of infection by Fusarium spp. and Phaeoisariopsis spp. The results indicate that planting date is an important consideration in improving the quality of hand-sorted farm-retained bean seed. <![CDATA[<b>Microbial counts of food contact surfaces at schools depending on a feeding scheme</b>]]> The prominence of disease transmission between individuals in confined environments is a concern, particularly in the educational environment. With respect to school feeding schemes, food contact surfaces have been shown to be potential vehicles of foodborne pathogens. The aim of this study was to assess the cleanliness of the surfaces that come into contact with food that is provided to children through the National School Nutrition Programme in central South Africa. In each school under study, microbiological samples were collected from the preparation surface and the dominant hand and apron of the food handler. The samples were analysed for total viable counts, coliforms, Escherichia coli, Staphylococcus aureus and yeasts and moulds. The criteria specified in the British Columbia Guide for Environmental Health Officers were used to evaluate the results. Total viable counts were high for all surfaces, with the majority of colonies being too numerous to count (over 100 colonies per plate). Counts of organisms were relatively low, with 20% of the surfaces producing unsatisfactory enumeration of S. aureus and E. coli and 30% unsatisfactory for coliforms. Yeast and mould produced 50% and 60% unsatisfactory counts from preparation surfaces and aprons, respectively. Statistically significant differences could not be established amongst microbial counts of the surfaces, which suggests cross-contamination may have occurred. Contamination may be attributed to foodstuffs and animals in the vicinity of the preparation area rather than to the food handlers, because hands had the lowest counts of enumerated organisms amongst the analysed surfaces. <![CDATA[<b>Determining the feasibility of harvesting invasive alien plant species for energy</b>]]> Woody invasive alien plants (IAPs) are a threat to South Africa's water resources, biodiversity and land productivity. The impacts of IAPs were the main reason for the South African government to embark on a natural resource management public works programme called Working for Water (WfW), which was aimed at controlling IAPs in a cost-effective yet labour-intensive way. At the same time, the high biomass of these species presents opportunities for synergies between the clearing of IAPs and the generation of biomass-based energy. The purpose of this study was to determine the cost of harvesting and extracting, chipping, and transporting the biomass, and also to determine the financial and economic feasibility of such an exercise from a commercial perspective. Sampling of the biomass was done at 31 representative sites within the Nelson Mandela Metropolitan Municipality, South Africa. The cost of the operation was carefully monitored, documented and reported at each stage, and compared to the cost of replacing the thermal coal currently used by industry within this municipality. The project proved to be financially viable, but only when the energy entrepreneur forms a partnership with the WfW programme, and then only under specific conditions. The project has, however, very high socio-economic returns with respect to a reduction in environmental externalities and job creation. <![CDATA[<b>Antibacterial, antioxidant activities and cytotoxicity of plants against <i>Propionibacterium acnes</i></b>]]> The use of plants to treat skin ailments has strong support in the current trend of drug discovery. Propionibacterium acnes, an anaerobic pathogen, plays an important role in the occurrence of acne. The present study was conducted to evaluate the antimicrobial and antioxidant activities against P acnes and cytotoxic effects of 48 medicinal plants grown in South Africa. The broth dilution and DPPH radical scavenging methods were used to determine antibacterial and antioxidant activities, respectively. Cytotoxicity was determined on mouse melanocytes (B16-F10). The ethanolic bark extract of Acacia galpinii Burtt Davy. (Leguminosae) exhibited the lowest minimum inhibitory concentration of 62.5 µg/mL. Excellent antioxidant activity was shown by Aspalathus linearis (Burm.f.) R.Dahlgren (Leguminosae), Combretum apiculatum Sond. (Combretaceae), Harpephyllum caffrum Bernh. ex Krauss (Anacardiaceae) and Sclerocarya birrea Hochst. (Anacardiaceae), with 50% radical scavenging activity (EC50) at concentrations ranging from 1.6 µg/mL to 3.5 µg/mL. Greyia sutherlandii Hook. & Harv. (Greyiaceae) also exhibited good antioxidant activity with an EC50 value of 7.9±0.23 µg/mL. A. linearis, G. sutherlandii and S. birrea showed low toxicity with 50% viability of cells (EC50) at concentrations of 125.09±0.71 pg/mL, 107.85±1.53 pg/mL and 92.07±0.09 pg/mL, respectively. The extracts of A. linearis, G. sutherlandii and S. birrea showed good antibacterial and antioxidant activities and low toxicity. Therefore, these plants can be considered as possible anti-acne agents and warrant further investigation. <![CDATA[<b>Biofilm formation in surface and drinking water distribution systems in Mafikeng, South Africa</b>]]> Poor quality source water and poorly treated reused wastewater may result in poor quality drinking water that has a higher potential to form biofilms. A biofilm is a group of microorganisms which adhere to a surface. We investigated biofilm growth in the drinking water distribution systems in the Mafikeng area, in the NorthWest Province of South Africa. Analysis was conducted to determine the presence of faecal coliforms, total coliforms, Pseudomonas spp. and Aeromonas spp. in the biofilms. Biofilms were grown on a device that contained copper and galvanised steel coupons. A mini tap filter - a point-of-use treatment device which can be used at a single faucet - was also used to collect samples. Scanning electron microscopy demonstrated that multi-species biofilms developed on all the coupons as well as on the point-of-use filters. Galvanised steel and carbon filters had the highest density of biofilm. Total coliforms, faecal coliforms and Pseudomonas spp. were isolated from raw water biofilm coupons only. Aeromonas spp. and Pseudomonas spp. were isolated from filters. The susceptibility of selected isolates was tested against 11 antibiotics of clinical interest. The most prevalent antibiotic resistance phenotype observed was KF-AP-C-E-OT-K-TM-A. The presence of virulence genes was determined using the polymerase chain reaction. These results indicate that bacteria present in the water have the ability to colonise as biofilms and drinking water biofilms may be a reservoir for opportunistic bacteria including Pseudomonas and Aeromonas species. <![CDATA[<b>Factors affecting graduation and student dropout rates at the University of KwaZulu-Natal</b>]]> This paper aims to introduce into the literature a competing risks methodology that can be used to help identify some student-specific and/or institutional factors which may be influencing the type of outcome experienced by a student when they leave the university system. Focusing on the length of time that it takes students to graduate or drop out from their studies, this new methodology was applied to a database comprising all students enrolled for a degree at the University of KwaZulu-Natal between the years 2004 and 2012. Financial aid and residence-based accommodation were found to help students who will eventually graduate to do so quicker in terms of the number of credit points that they have to repeat. These same factors, however, also cause someone who will eventually be excluded on academic grounds to linger longer in the system. By focusing on the number of extra credit points that it takes to reach a particular exit point, this paper introduces into the literature a new measure whose use will help to overcome some of the more obvious problems that can occur when one uses calendar time to measure the length of time that it takes to reach a particular exit point. <![CDATA[<b>Enterprise richness as an important characteristic of South African towns</b>]]> Towards the end of the 20th century there were almost 500 small towns of fewer than 50 000 persons in South Africa, accommodating about one tenth of the country's population. Little was known or said in national debates about the future of these places. A decade later this situation had changed and many studies have been or are being undertaken on small towns. For instance, the South African Government recognised that to stem the continued migration from rural to urban areas, a different approach was needed to economic development in rural municipalities and a 'Small Towns Regeneration Project' was initiated. Concerns about a perceived decline of rural towns also stimulated a quest to develop or find methods and/or measures to monitor the well-being of towns. Elsewhere in the world, small and medium enterprise 'observatories' were established to study and report on all aspects of small and medium enterprises, an approach recently followed in South Africa. New ways are needed to improve our understanding of the enterprise dynamics of South African towns. In this contribution, we examine the potential utility of the enterprise richness (i.e. the number of enterprise types) of South African towns and show that enterprise richness has a strong and fully quantifiable relationship with the total number of enterprises in the towns. This contribution adds a new dimension to the capability to make predictions about the enterprise structures of South African towns. <![CDATA[<b>Nelson Mandela's defence: A psychological capital documentary analysis</b>]]> This qualitative documentary analysis examines Nelson Mandela's defence statement at the Rivonia Trial, Pretoria Supreme Court, on 20 April 1964. The defence document is analysed through the psychological capital lens, depicting themes that support the constructs of hope, efficacy, resilience and optimism. Psychological capital characteristics played a major role in the initial non-violent policies of negotiation. The inevitable establishment of Umkhonto we Sizwe followed, as a result of the increased restrictions and unwillingness of government to negotiate and collaborate. Mandela showed a determined spirit to unite the country. The discussion gives insight into Mandela's authentic psychological capital leadership under difficult political and personal circumstances. Some implications are indicated in adopting Mandela's psychological characteristics for personal reform. <![CDATA[<b>Durham versus Durban: Quantifying productivity in astrophysics research</b>]]> Quantifying and rewarding research productivity is a contentious issue. In South Africa, there are at least two systems in wide use: peer assessment (as used by the National Research Foundation in providing researchers with individual ratings) and a simple publication count (used by the Department of Higher Education and Training to incentivise research output). At the University of KwaZulu-Natal (UKZN), the latter is used to grade the research performance of staff; however, this metric penalises those academics who work in large teams, as is increasingly common in astronomy. To test for correspondence between this metric and perceived research quality, I conducted a case study of the Extragalactic and Cosmology Group at Durham University in the UK, which is one of the leading astrophysics research groups in the world. I found that 44-74% of the permanent academic staff within this research group would not meet the research productivity target applied at UKZN in 2014. Given the disparity between this result and the esteem in which the research of the Durham group is held, I suggest that alternative methods of recognising and rewarding research output by funding agencies and universities should be explored, with an emphasis on quality rather than quantity.