Scielo RSS <![CDATA[South African Journal of Science]]> http://www.scielo.org.za/rss.php?pid=0038-235320170004&lang=pt vol. 113 num. 7-8 lang. pt <![CDATA[SciELO Logo]]> http://www.scielo.org.za/img/en/fbpelogp.gif http://www.scielo.org.za <![CDATA[<b>Worlds of awards</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S0038-23532017000400001&lng=pt&nrm=iso&tlng=pt <![CDATA[<b>Mother-to-child transmission of HIV and South Africa's 'HIV warrior'</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S0038-23532017000400002&lng=pt&nrm=iso&tlng=pt <![CDATA[<b>Discovering new host-directed therapies to treat inflammation</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S0038-23532017000400003&lng=pt&nrm=iso&tlng=pt <![CDATA[<b>Building needs-based healthcare technology competencies across Africa</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S0038-23532017000400004&lng=pt&nrm=iso&tlng=pt <![CDATA[<b>STIAS-Wallenberg Roundtable on mHealth: Towards a roadmap for image-based mobile technologies for health care</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S0038-23532017000400005&lng=pt&nrm=iso&tlng=pt <![CDATA[<b>The drive behind the legends of South African science</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S0038-23532017000400006&lng=pt&nrm=iso&tlng=pt <![CDATA[<b>The unique yet universal voice of South African sociology</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S0038-23532017000400007&lng=pt&nrm=iso&tlng=pt <![CDATA[<b>An environmental history of Angola</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S0038-23532017000400008&lng=pt&nrm=iso&tlng=pt <![CDATA[<b>The age of fossil StW573 ('Little Foot'): Reply to comments by Stratford et al. (2017)</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S0038-23532017000400009&lng=pt&nrm=iso&tlng=pt <![CDATA[<b>Banking regulations: An examination of the failure of African Bank using Merton's structural model</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S0038-23532017000400010&lng=pt&nrm=iso&tlng=pt <![CDATA[<b>Nanotechnology in South Africa - Challenges in evaluating the impact on development</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S0038-23532017000400011&lng=pt&nrm=iso&tlng=pt <![CDATA[<b>The function of a university in South Africa: Part 2</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S0038-23532017000400012&lng=pt&nrm=iso&tlng=pt <![CDATA[<b>The importance of monitoring the Greater Agulhas Current and its inter-ocean exchanges using large mooring arrays</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S0038-23532017000400013&lng=pt&nrm=iso&tlng=pt The 2013 Intergovernmental Panel on Climate Change report, using CMIP5 and EMIC model outputs suggests that the Atlantic Meridional Overturning Circulation (MOC) is very likely to weaken by 11-34% over the next century, with consequences for global rainfall and temperature patterns. However, these coupled, global climate models cannot resolve important oceanic features such as the Agulhas Current and its leakage around South Africa, which a number of studies have suggested may act to balance MOC weakening in the future. To properly understand oceanic changes and feedbacks on anthropogenic climate change we need to substantially improve global ocean observations, particularly within boundary current regions such as the Agulhas Current, which represent the fastest warming regions across the world's oceans. The South African science community, in collaboration with governing bodies and international partners, has recently established one of the world's most comprehensive observational networks of a western boundary current system, measuring the Greater Agulhas Current System and its inter-ocean exchanges south of Africa. This observational network, through its design for long-term monitoring, collaborative coordination of resources and skills sharing, represents a model for the international community. We highlight progress of the new Agulhas System Climate Array, as well as the South African Meridional Overturning Circulation programme, which includes the Crossroads and GoodHope hydrographic transects, and the South Atlantic MOC Basin-wide Array. We also highlight some of the ongoing challenges that the programmes still face. SIGNIFICANCE: •Large mooring arrays have been successfully deployed to monitor the Greater Agulhas Current system. •Capacity development is ongoing, although established, in marine science around South Africa. •Challenges exist with regard to retention of skilled staff, resources and funding. <![CDATA[<b>Wind speed characteristics and implications for wind power generation: Cape regions, South Africa</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S0038-23532017000400014&lng=pt&nrm=iso&tlng=pt Spatio-temporal dynamics of near-surface wind speeds were examined across the Northern, Western and Eastern Cape regions of South Africa. The regions assessed were geographically subdivided into three zones: coastal, coastal hinterland and inland. Wind speed data (10 m) were evaluated at monthly, seasonal, annual and zonal resolutions, with the aim to establish wind speed attributes and trends. Data from 19 weather stations with high-resolution wind records between 1995 and 2014 were evaluated. The majority of stations (79%) recorded a decrease in mean annual wind speed over the study period. The mean rate of decrease across all stations over the 20-year period equates to -1.25%, quantifying to an annual decrease of -0.002 m/s/year (-0.06% pa). The largest seasonal decline of -0.006 m/s/year (-0.15% pa) was recorded in summer. Statistically significant declines in mean annual wind speed are somewhat more pronounced for the coastal zone (-0.003 m/s/year, -0.08% pa) than over interior regions (-0.002 m/s/year, -0.06% pa) for the study period. The largest decrease (-0.08% pa) was recorded for the coastal zone, followed by the inland zone (-0.06% pa), equating to an annual reduction in available energy of 0.18% pa and 0.09% pa, respectively. When considering all stations over the study period, the mean inter-annual variability is 3.11%. Despite such decreases in wind speed, the variance identified in this study would not have posed any risk to power generation from wind across the assessed stations, based on the period 1995 to 2014. SIGNIFICANCE: • Mean recorded wind speed decreases have been marginal under recent (last 20 years) climatic conditions and change, thus adding confidence to the justification by the South African government to procure additional wind-generated electricity capacity. • Wind speed trends and variance measured over the research period (1995-2014) for the Cape stations in this study, would not have posed any risk to power generation from wind. • Only four stations (28.6%) recorded statistically significant trends at the 0.05% level; of these 75% were decreasing trends. • Coastal zones recorded a statistically larger decrease in mean wind speed compared to inland regions. • When considering all stations over the period 1995-2014, the mean inter-annual variability is 3.11%. <![CDATA[<b>Extreme 1-day rainfall distributions: Analysing change in the Western Cape</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S0038-23532017000400015&lng=pt&nrm=iso&tlng=pt Severe floods in the Western Cape Province of South Africa have caused significant damage to property and infrastructure over the past decade (2003-2014). The hydrological design criteria for exposed structures and design flood calculations are based mostly on the implicit assumption of stationarity, which holds that natural systems vary within an envelope of variability that does not change with time. This assumption was tested by examining the changes in extreme 1-day rainfall high percentiles (95th and 98th) and both the 20- and 50-year return period rainfall, comparing the period 1950-1979 against that of 1980-2009 across the province. A generalised Pareto distribution and a peaks-over-threshold sampling approach was applied to 76 rainfall stations across the province. Of these stations, 48 (63%) showed an increase in the 50-year return period 1-day rainfall and 28 (37%) showed a decrease in the 1980-2009 period at the 95th percentile peaks-over-threshold. At the 98th percentile peaks-over-threshold, 49 stations (64%) observed an increase and 27 (36%) a decrease for the later period. The change in the number of 3-day storms from the first to the second period is negligible, evaluated at 0.9% and 0.5% at the 95th and 98th percentile peaks-over-threshold levels, using cluster analysis. While there is no clear spatial coherency to the results, the general trend indicates an increase in frequency of intense rainfalls in the latter half of the 20th and early 21st centuries. These results bring into question assumptions of stationarity commonly used in design rainfall. SIGNIFICANCE: •63% of analysed rainfall stations in the Western Cape display an increase in 20- and 50-year 1-day rainfall extremes. •The results challenge the current assumptions of climate stationarity made in design rainfall estimations. •We propose an alternative methodology to rainfall extremes analysis for design flood estimation. •The methods employed can be replicated by future studies in other regions. <![CDATA[<b>Conservation implications of avian malaria exposure for African penguins during rehabilitation</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S0038-23532017000400016&lng=pt&nrm=iso&tlng=pt The African penguin (Spheniscus demersus) is the only penguin species that breeds on the African continent and it is currently classified as endangered. Its conservation is assisted by the Southern African Foundation for the Conservation of Coastal Birds (SANCCOB) which is a seabird rehabilitation facility based at the Rietvlei Wetland Reserve in Tableview, Cape Town. Despite the success of SANCCOB in rehabilitating diseased, injured or oiled penguins, significant mortalities have occurred at the facility as a result of avian malaria. Avian malaria can be contracted during rehabilitation during which penguins are inadvertently exposed to additional threats. An enzyme-linked immunosorbent assay (ELISA) was used to assess the anti-Plasmodium antibody levels of penguins to avian malaria on entry into the SANCCOB facility from 2001 to 2004 and during their rehabilitation process. Using blood smear data, avian malaria prevalence and malaria-related deaths were also monitored from 2002 to 2013. Significant increases in anti-Plasmodium antibody levels after admission were found during summer months. New infection and not parasite recrudescence was concluded to be the cause of this increase. This source was confirmed by a dramatic drop in penguin mortalities upon exclusion of mosquito vectors in 2008. Mortalities did not depend on the birds' abilities to produce an anti-Plasmodium antibody response and oiling had no influence on immunity or prevalence of avian malaria infections. This study highlights the importance of mosquito vector control to control pathogen exposure in wild bird rehabilitation centres. SIGNIFICANCE: •Efforts to assist with the conservation of endangered species can unintentionally add to the conservation burden. •Rehabilitation influences exposure of African penguins to avian malaria. •Avian malaria prevalence and mortality are not influenced by oiling or anti-Plasmodium antibody responses. •Vector control can limit avian malaria exposure in wild bird rehabilitation centres. <![CDATA[<b>A simulation study on the effect of climate change on crop water use and chill unit accumulation</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S0038-23532017000400017&lng=pt&nrm=iso&tlng=pt Climate change and its impact on already scarce water resources are of global importance, but even more so for water scarce countries. Apart from the effect of climate change on water supply, the chill unit requirement of deciduous fruit crops is also expected to be affected. Although research on crop water use has been undertaken, researchers have not taken the future climate into consideration. They also have focused on increasing temperatures but failed to relate temperature to chill unit accumulation, especially in South Africa. With a view of helping farmers to adapt to climate change, in this study we provide information that will assist farmers in their decision-making process for adaptation and in the selection of appropriate cultivars of deciduous fruits. Crop water use and chill unit requirements are modelled for the present and future climate. Results show that, irrespective of the irrigation system employed, climate change has led to increases in crop water use. Water use with the drip irrigation system was lower than with sprinkler irrigation as a result of efficiency differences in the irrigation technologies. It was also confirmed that the accumulated chill units will decrease in the future as a consequence of climate change. In order to remain in production, farmers need to adapt to climate change stress by putting in place water resources and crop management plans. Thus, producers must be furnished with a variety of adaptation or management strategies to overcome the impact of climate change. SIGNIFICANCE: •Producers must closely monitor the usage of efficient irrigation technology. •Climate adaptation needs to be anticipated years in advance and will require a transition to different crop species or cultivars or the development of management practices. •The results of this study will guide producers in the selection of cultivars when re-establishing their orchards. <![CDATA[<b>The role of plant breeders' rights in an evolving peach and nectarine fresh fruit sector</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S0038-23532017000400018&lng=pt&nrm=iso&tlng=pt The evolving impact of plant breeders' rights was investigated in a bid to provide a basis for understanding the complex relationship that exists between scientific, legislative and market matters that shape the peach and nectarine fresh fruit sector. The results show that there is complementarity among varietal legislation, deregularisation, international trade policies, market trends and research intensity. Plant varietal legislation is found to play a facilitative role in ensuring the growth in the sector which has evolved from merely facilitating access to better quality cultivars which were bred beyond South Africa's borders, to the provision of good quality germplasm that aids in the breeding of locally bred varieties which better meet the production needs of local farmers. The results of the analysis show that strengthened varietal legislation has contributed significantly to cultivar development, reduced varietal concentration, increased resource (land) utilisation and increased export revenue generation and market penetration. The study warns of the negative effects that widening the scope of the Plant Breeders' Rights Act would have on innovation and cultivar access by poor farmers. Because of the strong ties existing between innovation and R investment, the recommendation is for an increase in R investment in the local research institution. SIGNIFICANCE: •Insights into the impact of legislation on the industry's growth and development are given. •Empirical evidence related to the sector's performance of the innovation market is presented. <![CDATA[<b>Teacher participation in science fairs as professional development in South Africa</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S0038-23532017000400019&lng=pt&nrm=iso&tlng=pt This research was undertaken to understand the perceptions of the Physical Sciences teachers who participate in the South African 'Eskom Expo for Young Scientists', regarding the educational significance of the science fair, and the extent to which expo participation provides an opportunity for professional development. The educational significance of this article is found in its contribution to the professional identity of teachers in their roles as organisers, mentors and judges. The model of Beijaard et al. (Teach Teach Educ. 2004;20:107-128) was used to characterise the teachers' professional identity in terms of professional knowledge, attitudes, beliefs, norms and values, as well as emotions and agency. Interviews with the Physical Sciences teachers were analysed using thematic analysis, ultimately interpreting and linking the categories of responses to the theme of professional identity. The study found that expo participation contributes to pedagogical knowledge, content knowledge (as both procedural and declarative or factual knowledge) and pedagogical content knowledge. Self-efficacy beliefs were strengthened, positive attitudes were developed, and strategies of inquiry-based learning and effective methodological instruction were observed during participation, which contributed to the participants' school-based teaching. Teachers learn both from their engagement with learners, and through networking opportunities with fellow teachers. Teachers themselves value these aspects, and consequently, science fair participation is a sustainable form of professional development. It is recommended that the opportunity for professional development that is provided by teachers' participation in such school-level science fairs should be acknowledged and promoted by schools and fair organisers. SIGNIFICANCE: •Science expos offer professional development to participating teachers and improve learners' academic performance. <![CDATA[<b>The extent of South African authored articles in predatory journals</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S0038-23532017000400020&lng=pt&nrm=iso&tlng=pt We present a first estimate of the extent of predatory publishing amongst South African academics. This estimate is based on an analysis of all South African authored papers that qualified for subsidy over the period 2005 to 2014. The analysis shows that 4246 South African papers were published in 48 journals which we re-classified (refining Beall's classification) as either being probably or possibly predatory. A breakdown of these papers by year shows that the greatest increase in predatory publishing has occurred since 2011. Results are also presented of the distribution of these papers by individual university and scientific field. We conclude with some suggestions about predatory publishing and its pervasive consequence for our trust in science and how this should be addressed by the major stakeholders in the South African higher education system. SIGNIFICANCE: •This study is the first to analyse the extent of predatory publishing in South Africa. <![CDATA[<b>Scientific and non-scientific information in the uptake of health information: The case of Ebola</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S0038-23532017000400021&lng=pt&nrm=iso&tlng=pt The Ebola virus disease outbreak in West Africa (2013-2016) claimed over 10 000 lives in less than 18 months. Low levels of familiarity with the disease, ease of transmission, scale of infection, gruesomeness of symptoms, lack of cure and high fatality rate created a global panic. From the perspective of the social psychology of communication and content analysis, this study examines media coverage of the crisis in Africa with a view to unpacking the scientific and non-scientific information that may have framed public understanding of the disease. Findings show that accepting scientific advice was not unproblematic, because of the similarity of early symptoms with known diseases such as Lassa, dengue and malaria fevers. Cultural and religious actors and beliefs posed a paradox for believers as the public assimilated disease prevention information into existing norms and practices. Rumours and conspiracy theories about Western governments and pharmaceuticals also contributed to the rejection of the scientific explanation of its origin. Fear of the devastating effects of the disease and the lack of a cure led to the stigmatisation of the infected and treatment centres and ultimately to public revolts. Findings show the importance of non-scientific information and actors in matters of health and illness in Africa. SIGNIFICANCE: •Scientific knowledge is not enough to change health behaviour. Non-scientific knowledge and actors, traditional and religious practices, rumours and conspiracy theories must all be factored into efforts to address behavioural change. <![CDATA[<b>Women's representation in national science academies: An unsettling narrative</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S0038-23532017000400022&lng=pt&nrm=iso&tlng=pt Science academies are well placed to contribute towards strengthening of national systems of innovation through advocating for an increased participation of girls and women in science. To successfully do so, academies would need to overcome challenges faced with regard to women's representation in their own ranks and women's resultant full participation in the activities of national science academies. We collected baseline data on the representation of women scientists in the membership and governance structures of national science academies that are affiliated with IAP: the Global Network of Science Academies. Women academy members remained far below parity with men, given that women's membership was typically about 12%. Women members were better represented in the social sciences, humanities and arts but the corresponding shares rarely exceeded 20%. In the natural sciences and engineering, women's membership remained well below 10%. On average, the largest share of women members (17%) was associated with academies in Latin America and the Caribbean. The average share of women serving on governing bodies was 20%. To change this unsettling narrative, the importance of academies of science annually collecting, analysing and reporting gender-disaggregated data on membership and activities is highlighted as a key recommendation. Several aspects of women's representation and participation in national science academies are highlighted for further investigation. SIGNIFICANCE: •Demonstrates under-representation of women in national science academies. •Reports on results of the first gender-disaggregated survey on membership and governance of national science academies, globally. •Underscores the importance of regular collection, analysis and reporting of gender-disaggregated data in the science sector. <![CDATA[<b>Population irruption of the clam <i>Meretrix morphina</i> in Lake St Lucia, South Africa</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S0038-23532017000400023&lng=pt&nrm=iso&tlng=pt The thick-shelled clam Meretrix morphina, previously referred to as Meretrix meretrix, now occurs in the west Indian Ocean region, along the eastern seaboard of Africa, from the Red Sea to the Mlalazi Estuary, close to the Tugela River. Its presence in South Africa is only of recent recording. Meretrix morphina was detected for the first time in Lake St Lucia in 2000. The population declined and was not detected from 2005 until 2011, most likely as a result of a severe drought that resulted in widespread desiccation and hypersalinity in the lake. The system then experienced increased freshwater input resulting in lower salinities from 2011 until 2014, during which time M. morphina reappeared and their population gradually increased. In 2015, M. morphina became abundant in St Lucia, attaining unprecedented densities of 447 ind./m². Biomass, expressed as a fresh weight, varied in the different basins of St Lucia, ranging from 195 g/m² at Lister's Point to 1909.8 g/m² at Catalina Bay. However, in 2016, when drought conditions returned, M. morphina disappeared. This species appears to thrive under brackish salinities and high temperatures. It is able to establish large populations with high biomass and can become dominant. However, M. morphina is sensitive to desiccation and hypersaline conditions. This clam has substantial commercial value and is exploited along the African east coast, particularly in Mozambique. In future, it may feature more prominently in South African estuaries. However, the ecology of M. morphina is still largely unknown. SIGNIFICANCE: • First record of population irruption of M. morphina in South Africa. • Report on the largely unknown ecology of a commercially valuable bivalve. • Update on the taxonomy and poleward spread of M. morphina.