Scielo RSS <![CDATA[South African Journal of Science]]> http://www.scielo.org.za/rss.php?pid=0038-235320150001&lang=en vol. 111 num. 1-2 lang. en <![CDATA[SciELO Logo]]> http://www.scielo.org.za/img/en/fbpelogp.gif http://www.scielo.org.za <![CDATA[<b>What is on the horizon for science, technology and education in 2015?</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S0038-23532015000100001&lng=en&nrm=iso&tlng=en <![CDATA[<b>Dealing with the inevitable: Fire on table Mountain</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S0038-23532015000100002&lng=en&nrm=iso&tlng=en <![CDATA[<b>Restoration of the world in one book</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S0038-23532015000100003&lng=en&nrm=iso&tlng=en <![CDATA[<b>Approaches to large-class teaching</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S0038-23532015000100004&lng=en&nrm=iso&tlng=en <![CDATA[<b>Research Briefs</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S0038-23532015000100005&lng=en&nrm=iso&tlng=en <![CDATA[<b>Is Bt maize effective in improving South African smallholder agriculture?</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S0038-23532015000100006&lng=en&nrm=iso&tlng=en <![CDATA[<b>Global trends and opportunities for development of African research universities</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S0038-23532015000100007&lng=en&nrm=iso&tlng=en <![CDATA[<b>Energy efficiency and the law: A multidisciplinary approach</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S0038-23532015000100008&lng=en&nrm=iso&tlng=en South Africa is an energy-intensive country. The inefficient use of, mostly, coal-generated energy is the cause of South Africa's per capita contribution to greenhouse gas emissions, pollution and environmental degradation and negative health impacts. The inefficient use of the country's energy also amounts to the injudicious use of natural resources. Improvements in energy efficiency are an important strategy to stabilise the country's energy crisis. Government responded to this challenge by introducing measures such as policies and legislation to change energy consumption patterns by, amongst others, incentivising the transition to improved energy efficiencies. A central tenet underpinning this review is that the law and energy nexus requires a multidisciplinary approach as well as a multi-pronged adoption of diverse policy instruments to effectively transform the country's energy use patterns. Numerous, innovative instruments are introduced by relevant legislation to encourage the transformation of energy generation and consumption patterns of South Africans. One such innovative instrument is the ISO 50001 energy management standard. It is a voluntary instrument, to plan for, measure and verify energy-efficiency improvements. These improvements may also trigger tax concessions. In this paper, the nature and extent of the various policy instruments and legislation that relate to energy efficiency are explored, while the interactions between the law and the voluntary ISO 50001 standard and between the law and the other academic disciplines are highlighted. The introduction of energy-efficiency measures into law requires a multidisciplinary approach, as lawyers may be challenged to address the scientific and technical elements that characterise these legal measures and instruments. Inputs by several other disciplines such as engineering, mathematics or statistics, accounting, environmental management and auditing may be needed. Law is often described as the catalyst for change, building bridges between different academic disciplines, and driving behavioural changes that are not only enforced by government, but that are also voluntarily adopted by the users themselves. <![CDATA[<b>Realising high-dimensional quantum entanglement with orbital angular momentum</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S0038-23532015000100009&lng=en&nrm=iso&tlng=en We report the first quantum entanglement experiment in South Africa. The spatial modes of the entangled photon pair were investigated with their potential for high-dimensional entanglement. The generation, measurement and characterisation of the entangled states were examined in detail and we show high-dimensional entanglement in a Hilbert space of dimension 25. High-dimensional entanglement introduces the possibility for more secure communication and more efficient computations. We highlight the experimental challenges contained within each step and provide practical techniques for future experiments in the quantum regime. <![CDATA[<b>Imperatives for an agricultural green economy in South Africa</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S0038-23532015000100010&lng=en&nrm=iso&tlng=en Globally, there are social, economic and environmental challenges related to sustainable development; these challenges include climate change, the need to feed a rapidly increasing population, high rates of poverty and environmental degradation. These challenges have forced us to rethink the way in which development takes place, resulting in the emergence of the concept of a 'green economy'. A green economy results in improved human well-being and social equity, while significantly reducing risks to the environment. It is based on principles which integrate social, economic and environmental considerations. South Africa has adopted the principle of green economic growth, and agriculture is one of the sectors that will drive this growth. Agriculture could address some of the sustainable development problems, but there are challenges related to resource availability, environmental impacts of agriculture and climate change. For agriculture to support a green economy it has to be productive, contribute to economic growth and not undermine the environment, social and cultural systems. The information base and policies required to support a green economy in general, and/or an agriculture-supported green economy have not yet been developed, as the green economy is an emerging concept in South Africa as well as globally. The generation of such information requires analysis and synthesis of green economy principles and agricultural imperatives into generic principles and practices for facilitating agriculture's contribution to the green economy. In this paper, we conduct this analysis and synthesis and highlight the defining aspects of an agricultural green economy. <![CDATA[<b>Mother tongue as the medium of instruction at developing country universities in a global context</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S0038-23532015000100011&lng=en&nrm=iso&tlng=en One of the factors attributed to poor performance of some indigenous students at universities in developing countries is the use of a second language - mainly English and to some extent French - as the language of instruction at the universities. Consequently, policymakers in some developing countries have introduced, or are debating the idea of introducing, local vernacular languages as the official languages of instruction at their respective universities. Indeed, learning the official language of instruction as a second language is an additional hurdle, which to some extent hinders some students from performing well in their university studies. Thus students whose mother tongue is used as the language of instruction at their universities have an advantage over students whose mother tongue is not the language of instruction at their universities. Policies regarding the medium of instruction at universities have a range of short-term and long-term implications, some of which may be easily overlooked yet they may have far reaching repercussions for current and future generations. In this paper, a repertoire of pertinent issues surrounding the use of vernacular languages at universities is explored. These issues include performance of students, quality of graduates produced in terms of employability, university overall productivity, innovation, university competitiveness in the wake of globalisation, preservation of the vernacular languages and contribution towards national as well as global socio-economic development. <![CDATA[<b>Development of pesticide use maps for South Africa</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S0038-23532015000100012&lng=en&nrm=iso&tlng=en Over 3000 pesticides are registered for use in South Africa. Many studies have highlighted the movement of pesticides to agricultural crops from the point of application into non-target environments, particularly surface and groundwater resources. Exposure to pesticides can lead to serious human health and environmental effects. It is therefore important to identify critical areas where specific pesticides may result in a high risk of exposure to humans or the environment. Crop specific pesticide use data were obtained from a market research company and integrated into a geographical information system detailing the distribution of agricultural crops in South Africa as determined by an agricultural census performed in 2002. By estimating the total application of a specific pesticide to all crops produced in a magisterial district, it was possible to generate maps which provide an estimate of the application rate of over 200 pesticides per magisterial district. These maps were intersected with an agricultural land-cover map to provide a refined map giving details of the spatial distribution of pesticide use across the country. These maps are the first of their kind in South Africa and provide a spatial overview of the likely distribution of specific active ingredients based on the distribution of crops throughout the country. While there are a number of limitations and uncertainties associated with the data used to produce these maps, these are not unique to South Africa, and similar methodologies have been applied in more developed countries. <![CDATA[<b>Recognition of materials and damage on historical buildings using digital image classification</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S0038-23532015000100013&lng=en&nrm=iso&tlng=en Nowadays, techniques in digital image processing make it possible to detect damage, such as moisture or biological changes, on the surfaces of historical buildings. Digital classification techniques can be used to identify damages in construction materials in a non-destructive way. In this study, we evaluate the application of the object-oriented classification technique using photographs taken with a Fujifilm IS-Pro digital single lens reflex camera and the integration of the classified images in a three-dimensional model obtained through terrestrial laser scanning data in order to detect and locate damage affecting biocalcarenite stone employed in the construction of the Santa Marina Church (C√≥rdoba, Spain). The Fujifilm IS-Pro camera captures spectral information in an extra-visible range, generating a wide spectral image with wavelengths ranging from ultraviolet to infrared. Techniques of object-oriented classification were applied, taking into account the shapes, textures, background information and spectral information in the image. This type of classification requires prior segmentation, defined as the search for homogeneous regions in an image. The second step is the classification process of these regions based on examples. The output data were classified according to the kind of damage that affects the biocalcarenite stone, reaching an overall classification accuracy of 92% and an excellent kappa statistic (85.7%). We have shown that multispectral classification with visible and near-infrared bands increased the degree of recognition among different damages. Post-analysis of these data integrated in a three-dimensional model allows us to obtain thematic maps with the size and position of the damage. <![CDATA[<b>Assessing the quality of food served under a South African school feeding scheme: A nutritional analysis</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S0038-23532015000100014&lng=en&nrm=iso&tlng=en School feeding schemes have been implemented in various schools across the globe to improve the nutritional welfare of learners. The purpose of this study was to identify possible nutritional benefits or deficiencies of the foodstuffs served in the South African National School Nutrition Programme in the Free State Province (South Africa). Representative meal samples were collected from randomly selected schools and the nutrient content of meals was determined. The results were measured against nutrient-based standards for an average school lunch for individuals aged 7-10 and 11-18 years. The meals did not meet the nutrient standards for carbohydrate and energy contents for either age group. Protein standards were met by 90% of meals for individuals aged 7-10 years and by 40% for those aged 11-18 years. Only 10% of meals met the standards for calcium and zinc, while 80% and 30% met the iron standards for those aged 7-10 years and 11-18 years, respectively. The lipid and vitamin C contents were within standards. The implementation of proper storage and food preparation procedures may assist in preserving the quality of nutrients. <![CDATA[<b>Understanding of the farmers' privilege concept by smallholder farmers in South Africa</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S0038-23532015000100015&lng=en&nrm=iso&tlng=en Legislation on plant breeders' rights - the Plant Breeders' Rights Act, 1976 (Act No. 15 of 1976) - currently is being reviewed by the Department of Agriculture, Forestry and Fisheries. This legislation provides for farmers' privilege, which is one of the exceptions to plant breeders' rights. It allows farmers to save seed of protected varieties for their own use. Farmers' privilege, and particularly its impact on smallholder farmers in developing countries, is a widely debated issue. During the public consultation process, several comments proposing amendments to the farmers' privilege provision were received from various stakeholders. However, no comments were received from the smallholder farmers who may be directly impacted by this provision. This pilot study was undertaken to assess the understanding of the farmers' privilege concept by smallholder farmers from the historically disadvantaged communities and their current practices with regard to seed saving. The results showed that the majority of the smallholder farmers were not aware of the existence of the legislation on plant breeders' rights and therefore do not understand the farmers' privilege concept and its implications. They also did not know whether the varieties they were using were protected by plant breeders' rights or not. Little information has been published on the impact of plant breeders' rights in South Africa in general. We hope that this study might inform policy decisions on matters related to plant breeders' rights and the farmers' privilege. <![CDATA[<b>The prevalence of free-living amoebae in a South African hospital water distribution system</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S0038-23532015000100016&lng=en&nrm=iso&tlng=en The purpose of this study was to investigate the occurrence of free-living amoebae in the water system of a teaching hospital in Johannesburg (South Africa). Water and biofilm samples were collected from the theatres, theatre sterilisation service unit, central sterilisation service unit and endoscopy/bronchoscopy unit. The samples were filtered and seeded on non-nutrient agar spread with heat-killed Escherichia coli. Of the 71 samples collected, 63 (88.7%) were positive for free-living amoeba. Acanthamoeba spp., Balamuthia spp. and Hartmanella spp. were identified by morphology. The presence of free-living amoeba in the hospital water network may be a potential health risk. <![CDATA[<b>Plagiarism in South African management journals</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S0038-23532015000100017&lng=en&nrm=iso&tlng=en Plagiarism by academics has been relatively unexplored thus far. However, there has been a growing awareness of this problem in recent years. We submitted 371 published academic articles appearing in 19 South African management journals in 2011 through the plagiarism detection software program Turnitin™. High and excessive levels of plagiarism were detected. The cost to government of subsidising unoriginal work in these journals was calculated to approximate ZAR7 million for the period under review. As academics are expected to role model ethical behaviour to students, such a finding is disturbing and has implications for the reputations of the institutions to which the authors are affiliated as well as that of the journals that publish articles that contain plagiarised material.