Scielo RSS <![CDATA[South African Journal of Science]]> http://www.scielo.org.za/rss.php?pid=0038-235320120006&lang=en vol. 108 num. 11-12 lang. en <![CDATA[SciELO Logo]]> http://www.scielo.org.za/img/en/fbpelogp.gif http://www.scielo.org.za <![CDATA[<b>Changing of the guard at the Department of Science and Technology</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S0038-23532012000600001&lng=en&nrm=iso&tlng=en <![CDATA[<b>The reforestation of Africa?</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S0038-23532012000600002&lng=en&nrm=iso&tlng=en <![CDATA[<b>San origins and transition to the Later Stone Age</b>: <b>new research from Border Cave, South Africa</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S0038-23532012000600003&lng=en&nrm=iso&tlng=en <![CDATA[<b>Challenges in invasive alien plant control in South Africa</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S0038-23532012000600004&lng=en&nrm=iso&tlng=en <![CDATA[<b>Fynbos Proteaceae as model organisms for biodiversity research and conservation</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S0038-23532012000600005&lng=en&nrm=iso&tlng=en <![CDATA[<b>Strategies to overcome poverty and inequality</b>: <b>Towards Carnegie III</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S0038-23532012000600006&lng=en&nrm=iso&tlng=en <![CDATA[<b>80 Years after Taung</b>: <b>A review of <i>African Genesis</i></b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S0038-23532012000600007&lng=en&nrm=iso&tlng=en <![CDATA[<b>A history of crime in southern Africa - as revealed by bones</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S0038-23532012000600008&lng=en&nrm=iso&tlng=en <![CDATA[<b>Neville Alexander</b>: <b>Political philosopher (1936-2012)</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S0038-23532012000600009&lng=en&nrm=iso&tlng=en <![CDATA[<b>Kelly Chibale</b>: <b>An advocate of innovation</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S0038-23532012000600010&lng=en&nrm=iso&tlng=en <![CDATA[<b>How much time does it take to supervise a PhD student?</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S0038-23532012000600011&lng=en&nrm=iso&tlng=en http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S0038-23532012000600012&lng=en&nrm=iso&tlng=en <![CDATA[<b>Review of NGO performance research published in academic journals between 1996 and 2008</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S0038-23532012000600013&lng=en&nrm=iso&tlng=en Globally, literature on the performance of development non-governmental organisations (NGOs) has increased. However, little is known regarding the distinctive characteristics of academic articles on factors influencing NGO performance. In a recent systematic review of research, published in English-language academic journals between 1996 and 2008, factors influencing NGO performance were investigated. From the 31 journal articles that met the inclusion criteria, this study examined the salient characteristics of NGO performance research in terms of, (1) the number of publications, (2) publication outlets (journals and journal cluster), (3) author collaboration (sole or joint authors), (4) author affiliation, (5) study location, (6) study period, (7) study topics and (8) method and sources of information. Findings showed a steady increase in the number of articles, published in a wide array of journals with over half of the articles published in development studies journals. Of the 31 articles, 21 were sole authored. Data were mainly sought from NGO directors, programme staff and donors; comparatively fewer studies collected data from beneficiaries. Studies were mainly conducted in developing countries, whilst most authors were affiliated to institutions in developed countries. Of the 13 authors who conducted studies in Africa only 3 were affiliated to an institution in Africa. This study confirmed the continued need for increased research on factors influencing NGO performance; revealed the low seeking of beneficiaries' perspectives in NGO performance research despite the rhetoric of participatory development; and revealed the low number of published researchers in Africa and minimal collaborative efforts between 'Northern' and 'Southern' researchers in this field. <![CDATA[<b>The impact of solar ultraviolet radiation on human health in sub-Saharan Africa</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S0038-23532012000600014&lng=en&nrm=iso&tlng=en Photoprotection messages and 'SunSmart' programmes exist mainly to prevent skin cancers and, more recently, to encourage adequate personal sun exposure to elicit a vitamin D response for healthy bone and immune systems. Several developed countries maintain intensive research networks and monitor solar UV radiation to support awareness campaigns and intervention development. The situation is different in sub-Saharan Africa. Adequate empirical evidence of the impact of solar UV radiation on human health, even for melanomas and cataracts, is lacking, and is overshadowed by other factors such as communicable diseases, especially HIV, AIDS and tuberculosis. In addition, the established photoprotection messages used in developed countries have been adopted and implemented in a limited number of sub-Saharan countries but with minimal understanding of local conditions and behaviours. In this review, we consider the current evidence for sun-related effects on human health in sub-Saharan Africa, summarise published research and identify key issues. Data on the prevalence of human diseases affected by solar UV radiation in all subpopulations are not generally available, financial support is insufficient and the infrastructure to address these and other related topics is inadequate. Despite these limitations, considerable progress may be made regarding the management of solar UV radiation related health outcomes in sub-Saharan Africa, provided researchers collaborate and resources are allocated appropriately. <![CDATA[<b>William John Burchell</b>: <b>the multi-skilled polymath</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S0038-23532012000600015&lng=en&nrm=iso&tlng=en On the bicentenary of William John Burchell's sojourn and journey in southern Africa, we review his contribution to science in the region. In November 1810, Burchell arrived in Cape Town and, in mid-1811, he set off on a 4-year, 7000-km journey of scientific exploration. When he returned to Cape Town in April 1815, he had amassed 63 000 specimens and 500 drawings. Burchell is remembered mainly for his contributions to descriptive and philosophical aspects of natural history of the country. He is less well known for some significant and novel contributions to the earth sciences, the social sciences and even astronomy. Burchell's observations in physical geography and geology and his contribution to cartography have received little attention. In natural history, some of his views were prescient of the concepts of evolution and holism. In the social sciences, he provided unique ethnographic descriptions, developed an orthography of two indigenous languages and produced drawings that have attracted international research. William John Burchell is worthy of our memory. <![CDATA[<b>Next generation shotgun sequencing and the challenges of de novo genome assembly</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S0038-23532012000600016&lng=en&nrm=iso&tlng=en Sequencing the genomes of the many scientifically fascinating plants and animals found in South Africa is fast becoming a viable option as a result of the rapid and sustained drop in the cost of next generation sequencing over the last five years. However, the processing and assembly of the sequence data produced is not trivial. There are several factors which need to be taken into consideration when planning a strategy to assemble genome sequence data de novo. This paper reviews the advances and the challenges in two of the most rapidly developing areas of the field: the sequencing technology and the software programs used to assemble de novo the sequence data generated by these technologies into a genome. <![CDATA[<b>An assessment of zoological research collections in South Africa</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S0038-23532012000600017&lng=en&nrm=iso&tlng=en Natural science collections are accepted globally as critical research assets. A total of 71 zoological collections in South Africa, consisting of over 15 million specimens housed at 22 institutions, were assessed to determine their current status and to make recommendations for their future security. The two greatest challenges to the sustainability of the collections are (1) that natural science museums report to departments with an arts and culture rather than a science mandate and (2) staffing. The total staff complement within these 22 institutions is 115, with many collections understaffed or not staffed, and the loss of a single staff member often leaves a collection neglected and unused. Consolidation of collections so that there is a critical mass of staff is essential to address understaffing and would also allow for the establishment of a more dynamic research and curation environment. Consolidation under an appropriate department would also enable concentration of resources rather than dilution across all institutions, which would improve the storage environment (currently 28% of collections have reliable temperature control and only 8% (five collections) have humidity control), and increase the efficiency of the use of available funds (the curation budget was R1.08 million in 2009/2010 for all 71 collections). Consolidation could also ensure the improvement of data storage, management and dissemination, thereby increasing accessibility to the collections and the use of the collections for research. <![CDATA[<b>Re-evaluating the NO<sub>2</sub> hotspot over the South African Highveld</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S0038-23532012000600018&lng=en&nrm=iso&tlng=en Globally, numerous pollution hotspots have been identified using satellite-based instruments. One of these hotspots is the prominent NO2 hotspot over the South African Highveld. The tropospheric NO2 column density of this area is comparable to that observed for central and northern Europe, eastern North America and south-east Asia. The most well-known pollution source in this area is a large array of coal-fired power stations. Upon closer inspection, long-term means of satellite observations also show a smaller area, approximately 100 km west of the Highveld hotspot, with a seemingly less substantial NO2 column density. This area correlates with the geographical location of the Johannesburg-Pretoria conurbation or megacity, one of the 40 largest metropolitan areas in the world. Ground-based measurements indicate that NO2 concentrations in the megacity have diurnal peaks in the early morning and late afternoon, which coincide with peak traffic hours and domestic combustion. During these times, NO2 concentrations in the megacity are higher than those in the Highveld hotspot. These diurnal NO2 peaks in the megacity have generally been overlooked by satellite observations because the satellites have fixed local overpass times that do not coincide with these peak periods. Consequently, the importance of NO2 over the megacity has been underestimated. We examined the diurnal cycles of NO2 ground-based measurements for the two areas - the megacity and the Highveld hotspot - and compared them with the satellite-based NO2 observations. Results show that the Highveld hotspot is accompanied by a second hotspot over the megacity, which is of significance for the more than 10 million people living in this megacity. <![CDATA[<b>Shedding new light on an old mystery</b>: <b>early photographs of the Taung Child</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S0038-23532012000600019&lng=en&nrm=iso&tlng=en Although it was one of the most important events in the history of palaeoanthropology, many details of the Taung discovery and the events that followed it are still not completely elucidated. In this paper, we recount the events surrounding three early photographs (stored in the University of the Witwatersrand Archives) showing the Taung Child skull being held in the hands of the renowned anthropologist Raymond Dart. Having, what seems to be, a mosaic of evidence both for and against, we deliberate upon whether the archival photographs presented here are among the first photographs of the fossil itself or are of the first plaster cast of the Taung Child which was prepared for the 1925 British Empire Exhibition held at Wembley, London. We interpreted the photographs and determined their provenance through analyses which included historical examination of published accounts of the Taung discovery and archival materials, as well as comparisons of the photographed material in question with both archival and current (digital, high quality) photographs of the Taung fossil itself and Taung skull casts (as the skull underwent changes over time). We conclude that the early photographs presented here are of the original fossil itself and not of a cast. At the same time, these photographs represent some of the first pictorial depictions of the Taung Child skull. <![CDATA[<b>Semantic query in a relational database using a local ontology construction</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S0038-23532012000600020&lng=en&nrm=iso&tlng=en Semantic Web refers to a Web of linked data in which data can be shared and reused, allowing more uses than the traditional 'Web of documents'. However, most of the information on the Web is stored in relational databases and such databases cannot be used by the Semantic Web. Relational databases can, however, be used to construct an ontology as the core of the Semantic Web. We propose a new approach which enables Semantic Web applications to access data actually stored in relational databases using a corresponding ontology. In our approach, domain ontologies can be used to formulate relational database queries in order to simplify the data access of the underlying data sources. The method we propose involves two main phases: the construction of a local ontology from a relational database and a semantic query in a relational database using relational database query language (RDQL). In the first phase, we construct a Web ontology language ontology from data in a relational database. In the second phase, we propose a technique to automatically extract the semantics of relational databases and transform this information into a representation that can be processed and understood by a machine. The method proposed is simulated and implemented using Jena and the simulation results show the effectiveness of the proposed approach. Therefore, we propose RDQL as a real alternative to the commonly used structured query language access to relational databases. <![CDATA[<b>Processes for working-up an aqueous fluosilicic acid solution</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S0038-23532012000600021&lng=en&nrm=iso&tlng=en Aqueous fluosilicic acid solutions were once considered to be only adverse by-products of phosphoric acid production, which required treatment to prevent ecosystem destruction when discharged into the sea. However, a range of chemicals can be generated by the transformation of this industrial waste product. Through experiments undertaken in the laboratory, we have shown the possibility of caustic soda production. Volumetric analysis showed caustic soda to be present as a 6% - 7% solution with yields of about 70% - 80% by weight. Two processes were investigated for the caustification of sodium fluoride, using different precipitates: sodium chloride and ethanol and are described by modelling caustification curves. The activation energies of precipitation determined by semi-empirical correlations showed that precipitation by ethanol (E A = 933.536 J/mol) was more successful than precipitation by sodium chloride (E A = 7452.405 J/mol). Analyses performed on the precipitates highlighted compositions that are essential and useful constituents in the cement industry. <![CDATA[<b>Evidence of a therapsid scavenger in the Late Permian Karoo Basin, South Africa</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S0038-23532012000600022&lng=en&nrm=iso&tlng=en Dicynodonts are an extinct group of herbivorous non-mammalian therapsids ('mammal-like' reptiles) that are widely known from terrestrial Permo-Triassic strata throughout Pangaea. Dicynodont fossil remains are common within the Late Permian Beaufort Group of the Karoo Basin in South Africa. A large, partially articulated dicynodont skeleton recovered from the Tropidostoma Assemblage Zone is taphonomically important in having an unusual disarticulation pattern, bone surface punctures and a broken tooth of an unidentified carnivore associated with it. Here we report on the nature of the bone damage, and the identity of the carnivore that lost a canine tooth whilst scavenging the dicynodont carcass. The morphological characteristics of the serrations on the unidentified tooth were compared with those of contemporaneous carnivores, the gorgonopsians and therocephalians. Scanning electron microscopy analysis of a silicone cast of the unidentified tooth revealed distinctive 0.5-mm square-shaped serrations. Our comparative assessment of the tooth size, curvature, cross-sectional shape and morphology of the serrations revealed that the unidentified canine most closely matched Aelurognathus, a gorgonopsian known from the same assemblage zone.