Scielo RSS <![CDATA[South African Journal of Science]]> http://www.scielo.org.za/rss.php?pid=0038-235320160004&lang=pt vol. 112 num. 7-8 lang. pt <![CDATA[SciELO Logo]]> http://www.scielo.org.za/img/en/fbpelogp.gif http://www.scielo.org.za <![CDATA[<b>More scientific thinking needed to feed society: The NSTF tackles hunger</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S0038-23532016000400001&lng=pt&nrm=iso&tlng=pt <![CDATA[<b>Harry Oppenheimer Fellowship Awards, 2016</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S0038-23532016000400002&lng=pt&nrm=iso&tlng=pt <![CDATA[<b>From the ocean to outer space - and almost everything in between</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S0038-23532016000400003&lng=pt&nrm=iso&tlng=pt <![CDATA[<b>The new wild: The uncomfortable truth</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S0038-23532016000400004&lng=pt&nrm=iso&tlng=pt <![CDATA[<b>Citizens and cities: A South African review</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S0038-23532016000400005&lng=pt&nrm=iso&tlng=pt <![CDATA[<b>A primer for success in science</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S0038-23532016000400006&lng=pt&nrm=iso&tlng=pt <![CDATA[<b>A temporally constrained re-evaluation of temperature inferences from Boomplaas and isotope records from Cango Caves: Comments on Thackeray (2016)</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S0038-23532016000400007&lng=pt&nrm=iso&tlng=pt <![CDATA[<b>The possibility of lichen growth on bones of <i>Homo naledi: </i>Were they exposed to light?</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S0038-23532016000400008&lng=pt&nrm=iso&tlng=pt <![CDATA[<b>Science advisory role of national science academies</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S0038-23532016000400009&lng=pt&nrm=iso&tlng=pt <![CDATA[<b>Performance in Chemistry of students who started in the University Preparation Programme: The ripple effect</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S0038-23532016000400010&lng=pt&nrm=iso&tlng=pt <![CDATA[<b>A multi-disciplinary review of late Quaternary palaeoclimates and environments for Lesotho</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S0038-23532016000400011&lng=pt&nrm=iso&tlng=pt Lesotho provides a unique context for palaeoclimatic research. The small country is entirely landlocked by South Africa, yet has considerable variation in topography, climate, and associated vegetation over an approximate east-west transect. The region has been of archaeological interest for over a century, and hosts many Early to Late Stone Age sites with occupation preceding 80 000 years before present. The eastern Lesotho highlands are of interest to periglacial and glacial geomorphologists because of their well-preserved relict landforms and contentious evidence for permafrost and niche glaciation during the late Quaternary. However, continuous proxy records for palaeoenvironmental reconstructions for Lesotho are scarce and hampered by a range of methodological shortfalls. These challenges include uncertain ages, poor sampling resolution, and proxies extracted from archaeological excavations for which there may be bias in selection. Inferences on palaeoclimates are thus based predominantly on archaeological and palaeogeomorphological evidence for discrete periods during the late Quaternary. This review paper presents a more detailed multidisciplinary synthesis of late Quaternary conditions in Lesotho. We simultaneously considered the varying data that contribute to the under-studied palaeoenvironmental record for southern Africa. The collective palaeoenvironmental data for eastern Lesotho were shown to be relatively contradictory, with considerable variations in contemporaneous palaeoclimatic conditions within the study area. We argue that although methodological challenges may contribute to this variation, the marked changes in topography result in contrasting late Quaternary palaeoenvironments. Such environments are characterised by similar contrasting microclimates and niche ecologies as are witnessed in the contemporary landscape. These spatial variations within a relatively small landlocked country are of importance in understanding broader southern African palaeoenvironmental change. <![CDATA[<b>Development of census output areas with AZTool in South Africa</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S0038-23532016000400012&lng=pt&nrm=iso&tlng=pt The use of a single geographical unit to both collect and disseminate census data is common in many countries across the world, especially in developing countries. In South Africa this approach poses some challenges, as the design of small geographical units called enumeration areas to facilitate data collection differs considerably from the design of units that aid data analysis and interpretation. We aimed to create optimised census output areas using the Automated Zone-design Tool (AZTool) program, using the 2001 census enumeration areas as building blocks at various spatial levels, for both rural and urban settings in two South African provinces. The results were consistent and stable. The primary criterion of the confidentiality limit of 500 people was respected at all geographical levels or regions, in both urban and rural settings, for newly created optimised output areas. For the second criterion, lower intra-area correlation values at lower geographical levels for both rural and urban areas showed that higher geographical levels produced more homogeneous output areas than did lower geographical levels or regions. Our obtained intra-area correlation of 0.62 for the two provinces combined indicated that the selected homogeneity variables were good indicators of social homogeneity for creating optimised output areas in South Africa. We conclude that the AZTool software can be used to effectively and objectively create optimised output areas for South African data. Further research on the comparison of the newly created output areas with existing output areas in South Africa should be explored. <![CDATA[<b>Osteogenic tumour in <i>Australopithecus sediba: </i>Earliest hominin evidence for neoplastic disease</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S0038-23532016000400013&lng=pt&nrm=iso&tlng=pt We describe the earliest evidence for neoplastic disease in the hominin lineage. This is reported from the type specimen of the extinct hominin Australopithecus sediba from Malapa, South Africa, dated to 1.98 million years ago. The affected individual was male and developmentally equivalent to a human child of 12 to 13 years of age. A penetrating lytic lesion affected the sixth thoracic vertebra. The lesion was macroscopically evaluated and internally imaged through phase-contrast X-ray synchrotron microtomography. A comprehensive differential diagnosis was undertaken based on gross- and micro-morphology of the lesion, leading to a probable diagnosis of osteoid osteoma. These neoplasms are solitary, benign, osteoid and bone-forming tumours, formed from well-vascularised connective tissue within which there is active production of osteoid and woven bone. Tumours of any kind are rare in archaeological populations, and are all but unknown in the hominin record, highlighting the importance of this discovery. The presence of this disease at Malapa predates the earliest evidence of malignant neoplasia in the hominin fossil record by perhaps 200 000 years. <![CDATA[<b>Earliest hominin cancer: 1.7-million-year-old osteosarcoma from Swartkrans Cave, South Africa</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S0038-23532016000400014&lng=pt&nrm=iso&tlng=pt The reported incidence of neoplasia in the extinct human lineage is rare, with only a few confirmed cases of Middle or Later Pleistocene dates reported. It has generally been assumed that premodern incidence of neoplastic disease of any kind is rare and limited to benign conditions, but new fossil evidence suggests otherwise. We here present the earliest identifiable case of malignant neoplastic disease from an early human ancestor dated to 1.8-1.6 million years old. The diagnosis has been made possible only by advances in 3D imaging methods as diagnostic aids. We present a case report based on re-analysis of a hominin metatarsal specimen (SK 7923) from the cave site of Swartkrans in the Cradle of Humankind, South Africa. The expression of malignant osteosarcoma in the Swartkrans specimen indicates that whilst the upsurge in malignancy incidence is correlated with modern lifestyles, there is no reason to suspect that primary bone tumours would have been any less frequent in ancient specimens. Such tumours are not related to lifestyle and often occur in younger individuals. As such, malignancy has a considerable antiquity in the fossil record, as evidenced by this specimen. <![CDATA[<b>Developmental simulation of the adult cranial morphology of <i>Australopithecus sediba</i></b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S0038-23532016000400015&lng=pt&nrm=iso&tlng=pt The type specimen of Australopithecus sediba (MH1) is a late juvenile, prompting some commentators to suggest that had it lived to adulthood its morphology would have changed sufficiently so as to render hypotheses regarding its phylogenetic relations suspect. Considering the potentially critical position of this species with regard to the origins of the genus Homo, a deeper understanding of this change is especially vital. As an empirical response to this critique, a developmental simulation of the MH1 cranium was carried out using geometric morphometric techniques to extrapolate adult morphology using extant male and female chimpanzees, gorillas and humans by modelling remaining development. Multivariate comparisons of the simulated adult A. sediba crania with other early hominin taxa indicate that subsequent cranial development primarily reflects development of secondary sexual characteristics and would not likely be substantial enough to alter suggested morphological affinities of A. sediba. This study also illustrates the importance of separating developmental vectors by sex when estimating ontogenetic change. Results of the ontogenetic projections concur with those from mandible morphology, and jointly affirm the taxonomic validity of A. sediba. <![CDATA[<b>Diverse diets of the Mio-Pliocene carnivorans of Langebaanweg, South Africa</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S0038-23532016000400016&lng=pt&nrm=iso&tlng=pt The Mio-Pliocene guild of carnivorans of Langebaanweg (LBW), South Africa, is phylogenetically and ecologically diverse. Unlike modern African fauna, this fossil sample contains a large ursid; although there are mustelids, herpestids and viverrids in Africa today, some of the LBW members of those families were much larger than their modern confamilials. There were also numerous felid species, including some that possess a more sabretoothed dental morphology, as well as several species of hyaenids that were very different from their modern confamilials. Questions remain about the dietary morphospace occupied by these fossils. Which taxa were predominately durophagous and which were the most hypercarnivorous? Did the level of durophagy and hypercarnivory in the LBW taxa reach the level of specialisation found in modern carnivores? In the current study, we evaluate the dietary specialisations of all the large terrestrial LBW carnivorans through analysis of the radii-of-curvature and intercuspid notches present in the mandibular dentition. We found that the LBW carnivorans had less sharp premolars than do their modern confamilials -an indication of greater durophagy. However, some families contain individuals with more extreme intercuspid notch patterns, indicating greater hypercarnivory. The ursid also possessed a suite of morphology unlike any modern carnivoran, exhibiting some morphology conducive to durophagy and some that places it functionally among the most hypercarnivorous of modern carnivorans. Thus it was likely capable of consuming high levels of both flesh and bone. <![CDATA[<b>Archiving South African digital research data: How ready are we?</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S0038-23532016000400017&lng=pt&nrm=iso&tlng=pt Digital data archiving and research data management have become increasingly important for institutions in South Africa, particularly after the announcement by the National Research Foundation, one of the principal South African academic research funders, recommending these actions for the research that they fund. A case study undertaken during the latter half of 2014, among the biological sciences researchers at a South African university, explored the state of data management and archiving at this institution and the readiness of researchers to engage with sharing their digital research data through repositories. It was found that while some researchers were already engaged with digital data archiving in repositories, neither researchers nor the university had implemented systematic research data management. <![CDATA[<b>Effects of animal class and genotype on beef muscle nanostructure, pH<sub>u</sub>, colour and tenderness</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S0038-23532016000400018&lng=pt&nrm=iso&tlng=pt The objective of the study was to determine the effects of animal class and genotype of cattle on Muscularis longissimus thoracis et lumborum (LTL) nanostructure, ultimate pH (pHu), colour and tenderness of beef. We found significant positive relationships between distance travelled (DT) and meat temperature (Tm) (p<0.01); lairage duration (LDhr) and lightness of colour (L*) (p<0.01); ambient temperature (Ta) and L* (p<0.05) and LDhr and yellowness (b*) (p<0.05) of beef from Bonsmara cattle. Positive linear relationships were observed between DT and Tm(p<0.05) and DT and L* (p<0.01) of the non-descript cattle. There were no significant relationships between pre-slaughter stress and other beef quality parameters (pHu, Warner-Bratzler shear force [WBSF], redness [a*] and b*) of Bonsmara, Nguni and non-descript cattle. Muscle fibres differed among class and genotype and had an effect on meat quality. The Bonsmara, non-descript and Nguni cows and heifers had visible skeletal muscle fibres which were thin and long, promising improved tenderness of beef. Genotype and class had significant effects on meat quality parameters (Tm, pHu, L*, a*, b* and WBSF). The first important principal components as they appeared from the analysis were pHu, Tm, L*, a*, b* and WBSF. Therefore, animal class did not affect the nanostructure of beef; instead, meat tenderness was enhanced by the longer and visible muscle fibres. Nguni cattle produced meat of superior quality to that of the Bonsmara and the non-descript cattle. <![CDATA[<b>Inward foreign direct investment and transfer of environmentally sound technology in Angola</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S0038-23532016000400019&lng=pt&nrm=iso&tlng=pt Many developing countries have relied on foreign direct investment as a primary means to acquire technologies. However, there has been inadequate empirical research on the nexus between foreign direct investment and the transfer of environmentally sound technology (EST), specifically focused on African countries. In this paper I explore whether inward foreign direct investment in Angola's energy sector has indeed transferred ESTs. My study encompasses illustrative case studies specifically related to energy firms, and the data were drawn from literature and in-depth individual interviews. The results indicate that Angola has used its national policy framework and institutions to promote inward foreign direct investment, and has harnessed appropriate international regimes to acquire ESTs. Countries may therefore invoke sovereignty principles enshrined in constitutional provisions, or may utilise international regimes to attract ESTs through foreign direct investment. I recommend that further studies be conducted to explore this subject area, drawing examples from other African countries and differing economic sectors. <![CDATA[<b>Estimated abundance and diversity of heterotrophic protists in South African biocrusts</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S0038-23532016000400020&lng=pt&nrm=iso&tlng=pt Biological soil crusts (biocrusts) occur widely in the uppermost millimeters of the soil in arid and semi-arid systems. Worldwide they cover large terrestrial areas and play a major role in the global terrestrial carbon and nitrogen cycles. However, knowledge of the microbial decomposer foodwebs within biocrusts is particularly scarce. Heterotrophic protists in soil are predominantly bacterivores, and because of their high biomass compared with other soil fauna and fast turnover rates, protists are considered an important factor for soil nutrient cycling and energy fluxes. Thus, knowledge of their biodiversity, abundance and functional roles is important to understand soil ecosystem functions. We investigated the diversity and abundance of heterotrophic soil protists in different types of biocrusts from the Succulent Karoo, South Africa. With an overall diversity of 23 distinct morphotypes, soil protist biodiversity was shown to be high. The most abundant groups were Spumella-like chrysomonads, gliding bodonids, glissomonads and heteroloboseans. Protist abundance was highly variable among samples. The abundance and diversity did not differ significantly among different types of biocrusts, indicating that microscale differences, but not macroscopic soil crust builders (e.g. cyanobacteria, lichens and bryophytes), have a major impact on the protist community. <![CDATA[<b>The stable isotope setting of <i>Australopithecus sediba </i>at Malapa, South Africa</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S0038-23532016000400021&lng=pt&nrm=iso&tlng=pt We report δ13C and δ18O results from carbonate-cemented cave sediments at Malapa in South Africa. The sediments were deposited during a short-period magnetic reversal at 1.977±0.003 Ma, immediately preceding deposition of Facies D sediments that contain the type fossils of Australopithecus sediba. Values of δ13C range between -5.65 and -2.09 with an average of -4.58±0.54°‰(Vienna Pee Dee Belemnite, VPDB) and values of δ18O range between -6.14 and -3.84 with an average of -4.93±0.44°‰(VPDB). Despite signs of diagenetic alteration from metastable aragonite to calcite, the Malapa isotope values are similar to those obtained in two previous studies in South Africa for the same relative time period. Broadly, the Malapa δ13C values provide constraints on the palaeovegetation at Malapa. Because of the complex nature of the carbonate cements and mixed mineralogy in the samples, our estimates of vegetation type (C4-dominant) must be regarded as preliminary only. However, the indication of a mainly C4 landscape is in contrast to the reported diet of A. sediba, and suggests a diverse environment involving both grassland and riparian woodland. <![CDATA[<b>Universities are becoming major players in the national system of innovation</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S0038-23532016000400022&lng=pt&nrm=iso&tlng=pt Based on data from South Africa's research and development (R) surveys, the country's R expenditure has grown in real terms by 52% over the period 2001 to 2012. This growth has been driven by government funding, which rose from 34% of the total funding in 2003 to 45% by 2012. Much of the additional funding has been granted to universities, with government support of R in this sector rising 450% in nominal terms, or 250% in real terms, over the same period. This funding focus, indicative of a growing role for universities as R performers within the national system of innovation, follows a pattern set earlier in many developed countries and reflects a revision in the state's steering of knowledge creation. The R Survey also revealed a decline in the average cost of research, as expressed by expenditure per full-time equivalent researcher. This finding suggests that the researcher labour market is being better supplied and the constraints identified by earlier reviews are slowly being overcome. Both trends are highly positive for the research system. However, the 34% decline in business R expenditure since its peak in 2008 is a matter of concern and needs to be addressed. In particular, the level of state-industry embeddedness must be increased to encourage private investment and to overcome South Africa's present growth constraints in respect of developing competitive medium- to high-technology sectors. <![CDATA[<b>Reptiles sold as traditional medicine in Xipamanine and Xiquelene Markets (Maputo, Mozambique)</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S0038-23532016000400023&lng=pt&nrm=iso&tlng=pt Zootherapy plays a role in healing practices in Mozambican society. Although several studies have focused on ethnobotany and traditional medicine in the country, little research has been conducted on the use of reptiles in zootherapy. The aim of this study was therefore to fill this gap by assessing the reptile species traded for traditional medicine in the Xipamanine and Xiquelene Markets in Maputo, Mozambique. We found that few reptile species are traded domestically for traditional medicine and that their use appears to be in decline in Mozambique. Our findings also suggest that the domestic trade of reptiles for traditional medicines in Maputo markets is unlikely to have a significant impact on the conservation of reptiles in Mozambique. However, we suggest that international trade with South Africa is likely having a larger impact, given observations of Mozambican nationals selling a diverse range of fauna in urban traditional medicine markets in Johannesburg and Durban. <![CDATA[<b>A unique fingerprint? Factors influencing attitudes towards science and technology in South Africa</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S0038-23532016000400024&lng=pt&nrm=iso&tlng=pt From an international perspective, research in the field of public attitudes towards science and technology has been conducted since the 1970s. A frequently articulated - and empirically supported - assumption is that strong interest in and knowledge about science in a society is associated with more favourable attitudes towards science. This positive attitude in turn affects support for public funding of science. However, this research field is not without controversy, and for the South African population many questions remain unanswered. Initial research has not explored the factors that shape attitudes towards science and technology in detail. We re-analysed data from the Human Sciences Research Council to explore the above assumption. Interestingly, for the South African population, higher levels of scientific literacy and use of information sources are associated with more promises but also more reservations towards science and technology. This is especially true for relatively young and educated survey respondents. In international comparison, South Africa shows a unique fingerprint to some extent, but also shares characteristics with industrially developing countries of Europe (such as Greece or Portugal). To understand the correlations better, future research should aim to examine the overall picture when investigating the diverse South African population more extensively. <![CDATA[<b>Two dung beetle species that disperse mimetic seeds both feed on eland dung</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S0038-23532016000400025&lng=pt&nrm=iso&tlng=pt Scarabaeus spretus zur Strassen was observed to roll and bury Ceratocaryum argenteum (Restionaceae) seeds in the sandplain fynbos of the Potberg area of the De Hoop Nature Reserve, South Africa. This species is the second dung beetle species found to be deceived by the faecal mimicry of C. argenteum seeds - the first species being Epirinus flagellatus. An isotopic analysis suggests that both these dung beetle species most likely feed on eland (Taurotragus oryx), not bontebok (Damaliscus pygargus pygargus), dung. Thus the model in this mimicry is eland dung; this interaction suggests large herbivores are an integral part of this fynbos. <![CDATA[<b>Anaerobic digestion of donkey dung for biogas production</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S0038-23532016000400026&lng=pt&nrm=iso&tlng=pt Biogas can provide a solution to some of South Africa's energy needs, especially in rural areas of the Eastern Cape province that have plentiful biogas substrates from donkeys, goats, sheep, cattle and chicken. We investigated the effectiveness of donkey dung for biogas production using a designed and constructed cylindrical field batch biogas digester. The donkey dung was collected from the University of Fort Hare's Honeydale Farm and was analysed for total solids, volatile solids, total alkalinity, calorific value, pH, chemical oxygen demand and ammonium nitrogen. The biogas composition was analysed using a gas analyser. We found that donkey dung produced biogas with an average methane yield of 55% without co-digesting it with other wastes. The results show that donkey dung is an effective substrate for biogas production.