Scielo RSS <![CDATA[South African Journal of Science]]> http://www.scielo.org.za/rss.php?pid=0038-235320180003&lang=es vol. 114 num. 5-6 lang. es <![CDATA[SciELO Logo]]> http://www.scielo.org.za/img/en/fbpelogp.gif http://www.scielo.org.za <![CDATA[<b>The Fourth Industrial Revolution and education</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S0038-23532018000300001&lng=es&nrm=iso&tlng=es <![CDATA[<b>Towards human development friendly universities</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S0038-23532018000300002&lng=es&nrm=iso&tlng=es <![CDATA[<b>A new look at Old Fourlegs</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S0038-23532018000300003&lng=es&nrm=iso&tlng=es <![CDATA[<b>Decolonising engineering in South Africa - Experience to date and some emerging challenges</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S0038-23532018000300004&lng=es&nrm=iso&tlng=es <![CDATA[<b>Response to Benoit and Thackeray (2017): 'A cladistic analysis of <i>Graecopithecus'</i></b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S0038-23532018000300005&lng=es&nrm=iso&tlng=es <![CDATA[<b>A temperature index in a Late Quaternary sequence at Wonderkrater, South Africa</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S0038-23532018000300006&lng=es&nrm=iso&tlng=es <![CDATA[<b>Psychrophiles: Ecological significance and potential industrial application</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S0038-23532018000300007&lng=es&nrm=iso&tlng=es The bulk of earth's biosphere is cold (<5 °C) that sustains a broad diversity of microbial life by triggering physiological response(s) to ensure survival in cold and frozen ecosystems. The strategy of adaptation to cold environments includes changes in membrane composition and induction of a set of specific cold-active proteins, polyunsaturated lipids and exopolysaccharides. These adaptive features provide an enormous natural reservoir of enzymes that function effectively in cold environments, and these cold-active enzymes have been targeted for innovative applications useful to humankind. This review provides an overview of the existence, distribution and adaptation strategies of psychrophilic microorganisms worldwide with great emphasis on their recently emerged industrial applications in the textile industry, food and dairy industry, brewing and wine industry, laundry detergent industry, and others. SIGNIFICANCE: •The outcome of these studies may also help in the exploration of the possibility of life in distant frozen planets. <![CDATA[<b>Trends in behavioural ecology: Putting South African research in a global perspective</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S0038-23532018000300008&lng=es&nrm=iso&tlng=es South Africa remains at the leading edge of scientific publishing on the African continent, yet few analyses of publication patterns exist outside the biomedical field. Considering the large number of protected areas and mammalian guilds within the country, I examined trends in South African ecological research as it pertains to the behaviour of mammals. I assessed the topics and taxonomic focus of mammalogists at South African institutes over the span of 15 years (2001-2015), and contrasted local research with the shifting focus of international behavioural research. This review of more than 1000 publications indicates that South African based researchers exhibit a strong tendency towards field-based research, as opposed to laboratory-centred experiments. In terms of topical focus, local ecologists place significant weight on the behavioural categories of mating, social and foraging behaviour - reflecting a global priority for these topics. This finding contrasts with an increased emphasis on animal cognition and communication research in the international research arena, including field-based studies on these themes. I make suggestions on how behavioural ecologists in South Africa can align themselves with global trends while also continuing to distinguish those facets that make South African behavioural ecology unique. SIGNIFICANCE: • This review is the first of behavioural ecology in South Africa. • Suggestions are made for where South African researchers can profitably shift research focus. • International trends in behavioural ecology are highlighted. <![CDATA[<b>Privacy and user awareness on Facebook</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S0038-23532018000300009&lng=es&nrm=iso&tlng=es Users' privacy on social media platforms continues to be important as users face numerous threats to their personal data. Social media sites such as Facebook store large amounts of users' personal data which make such sites prime targets for hackers. Research has shown that users have been subjected to privacy attacks in which hacked personal data are sold to online marketers. These incidents have prompted the need to protect users' privacy against data theft by third parties. We investigated the privacy risks that social media users on Facebook face when online. The privacy awareness of regular users of Facebook was evaluated through the observation of their online activities. Facebook was selected as a case study because it is the largest and most popular social media platform in South Africa. A sample group of Facebook users was selected for this study based on their activeness (or frequency of posting, uploaded or liking) on the site. Findings indicate that users' personal data can be obtained as they are publicly available on Facebook. The implication of this finding is that users lack adequate awareness on protection tools designed to protect their personal data, and as a result, they risk losing their data and privacy. SIGNIFICANCE: • This study serves as an assessment tool for the privacy and security features of the social media site Facebook. This assessment tool can help users of social media sites to evaluate their own behaviour and usage patterns on Facebook. It can also assist social media site designers in considering the effectiveness of current measures, which are designed to ensure that the privacy and safety of users are protected. <![CDATA[<b>Cultural differences and confidence in institutions: Comparing Africa and the USA</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S0038-23532018000300010&lng=es&nrm=iso&tlng=es A comparison was undertaken of confidence in 17 institutions in Ghana, Nigeria, Zimbabwe and the USA using data from the World Values Survey to find shared valuations and distinguishing characteristics as markers of cultural categories. Frequencies and rankings were examined and exploratory factor analysis was used to find plausible meanings of groups of institutions. The findings show that, although African respondents score institutions higher than their US counterparts, the rankings vary. With frequencies, the meaning is manifest. The analysis shows that 10 institutions load similarly on one latent variable and their combinations with the others indicate culture-specific characteristics. The latent variables were named 'not-for-profit', 'for-profit', 'political', 'watchdog or fourth estate' and 'social order' and they show Ghana is closer to the USA than to Nigeria, which is closer to Zimbabwe. The 'not-for-profit' variable is more important in the USA and Ghana and 'political' is more important in Nigeria and Zimbabwe. Institutional-specific loadings show that whereas the police and courts are grouped as 'political' in Nigeria, in other countries they belong to 'social order'; and while universities are perceived as 'for-profit' in Africa, they are 'not-for-profit' in the USA. Comparing frequencies and rankings or dividing along the lines of individualistic versus collective or private and public sectors, masks the dynamic distribution of the systems of meaning in the local cultures; the latent variables approach therefore offers a more conceptually sound categorisation informed by shared and distinguishing institutions. SIGNIFICANCE: • Nigerians, as at the time of the survey, were yet to perceive the principles of separation of powers between political institutions, the judiciary and the police - an essential feature of a good democracy and a characteristic of other countries in the study. Zimbabweans and Nigerians perceive their public institutions in generally the same way with the domination of the political establishments while Ghanaians are closer to the USA in terms of the values they attach to their establishments with the most important group being the charities. The universities in Africa, as well as the civil service in Nigeria, are associated with business/ profit centres with the Nigerian labour movement also seen as political. The army also remains relevant as a part of the fourth estate in Ghana and Nigeria. <![CDATA[<b>Household food waste disposal in South Africa: A case study of Johannesburg and Ekurhuleni</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S0038-23532018000300011&lng=es&nrm=iso&tlng=es Food waste is becoming an important issue in light of population growth and global food security concerns. However, data on food wastage are limited, especially for developing countries. Global estimates suggest that households in developed countries waste more food than those in developing countries, but these estimates are based on assumptions that have not been tested. We therefore set out to present primary data relating to household food waste disposal for South Africa within the sub-Saharan African context. As the Gauteng Province contributes about 45% of the total municipal waste generated in South Africa, the case study area covers two of the large urban metropolitan municipalities in Gauteng, namely Ekurhuleni and Johannesburg, with a combined population of 8.33 million, representing nearly 15% of the South African population. Municipal solid waste characterisation studies using bulk sampling with randomised grab sub-sampling were undertaken over a 6-week period during summer in 2014 (Johannesburg) and 2016 (Ekurhuleni), covering a representative sample of the municipal waste collection routes from households in each of the two surveyed municipalities. The food waste component of the household waste (excluding garden waste) was 3% in Ekurhuleni and 7% in Johannesburg. The results indicate that an average of 0.48 kg (Ekurhuleni) and 0.69 kg (Johannesburg) of food waste (including inedible parts) is disposed of into the municipal bin per household per week in the two municipalities, respectively. This translates into per capita food waste disposal of 8 kg and 12 kg per annum, respectively, in South Africa as compared to the estimated 6-11 kg per annum in sub-Saharan Africa and South and Southeast Asia. SIGNIFICANCE: • Research on food waste in developing countries is limited. • This study is the first of its kind undertaken in South Africa. • Food waste research is important to address food security issues. • This study provides evidence to support Sustainable Development Goal 12.3. <![CDATA[<b>Revelations from an online diagnostic arithmetic and algebra quiz for incoming students</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S0038-23532018000300012&lng=es&nrm=iso&tlng=es A review of relevant literature revealed that research indicates an alarming number of secondary school students who enter tertiary institutions display a serious lack of mathematical basics required for the study of university mathematics. This so-called change from the secondary school to tertiary study of mathematics has become an important field of mathematical learning research. In this context, at the University of KwaZulu-Natal, online diagnostics for pre-calculus knowledge and skills were made available to first-year mathematics students. We report here on some findings from an analysis of the provision of diagnostic questions for basic arithmetic and algebra. The results show that the diagnostic questions which were in the form of an online quiz assisted students to cope with their mathematics module in the sense that it positively impacted on the final results of students who attempted the quiz. SIGNIFICANCE: • Students who completed an online quiz on basic arithmetic and algebra to identify their strengths and weaknesses indicated that the quiz prepared them for the material they had to study for their mathematics module. <![CDATA[<b>The Grootfontein aquifer: Governance of a hydro-social system at Nash equilibrium</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S0038-23532018000300013&lng=es&nrm=iso&tlng=es The Grootfontein groundwater aquifer is important to the water supply of the town Mahikeng in the North West Province of South Africa and to commercial agriculture in the Province, but the water table has fallen by up to 28 m as a consequence of over-abstraction since the 1980s. Institutional and hydrogeological issues impact the aquifer in complex ways, described here as a hydro-social system. Whilst the hydrogeology is well understood and South African laws provide for sustainable groundwater governance, poor stakeholder collaboration and other institutional problems mean that the over-abstraction is likely to persist - an example of an undesirable Nash equilibrium. The Grootfontein aquifer case shows that groundwater underpins wider social-ecological-economic systems, and that more holistic management - taking the institutional context into account - is needed to underpin economic growth, employment and other public outcomes. SIGNIFICANCE: • The cost of better natural resource stewardship, including groundwater, is likely to be considerably less than the losses that occur when it is absent. • If local groundwater was better managed, it could make water supplies in Mahikeng cheaper and more reliable, which would in turn support local economic growth and employment. <![CDATA[<b>Farmer groups and inorganic fertiliser use among smallholders in rural South Africa</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S0038-23532018000300014&lng=es&nrm=iso&tlng=es Smallholder farmers in developing countries are characterised by low uptake of improved farm inputs and weak links to markets. Among other reasons, the high transaction costs that these smallholder farmers incur, as a result of their location in remote areas, inadequate information and missing credit markets, inhibit them from participating in both input and output markets. Organising farmers into groups has been suggested as a potential mechanism for reducing transaction costs. Accordingly, farmer groups have been preferred channels for smallholder farmer support in South Africa, both by the government and donors. However, the impact of these groups on smallholder outcomes such as technology adoption is largely unknown. We investigated the extent to which membership in farmer groups influences the use of improved farm inputs such as inorganic fertiliser among smallholder farmers in South Africa. A sample of 984 households was analysed using the propensity score matching method. Group membership was found to play a positive role in inorganic fertiliser use with a 14% higher chance of inorganic fertiliser use among group members. Among fertiliser users, group members used 170 kg more inorganic fertiliser than did non-members. Further analysis indicated that the effect of group membership on inorganic fertiliser use was heterogeneous among group members. The results suggest that farmer groups play a positive role in the use of improved farm inputs in South Africa. For greater effectiveness of group membership, policymakers should target the less educated, increase the assets of the poor and improve access to extension and information. SIGNIFICANCE: • The impact of farmer groups on smallholder outcomes such as technology adoption is largely unknown. • Farmer groups were found to play a positive role in the adoption of agricultural technologies such as inorganic fertilisers. • Effect of group membership on inorganic fertiliser adoption was heterogeneous among group members. • Variables that should be targeted for greater effectiveness of collective action were identified. <![CDATA[<b>Power laws, demography and entrepreneurship in selected South African regions</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S0038-23532018000300015&lng=es&nrm=iso&tlng=es Statistically significant Pareto-like log-log rank-size distributions were recorded for population and enterprise agglomeration in the towns of three different regions of South Africa, and are indicative of skewed distributions of population and enterprise numbers in regional towns. There were no distinct differences between groups of towns of regions from different parts of the country. However, the regional agglomerations differed from those of groups of towns randomly selected from a database. Regions, therefore, appear to have some uniqueness regarding such agglomerations. The identification of Zipf-like links between population and enterprise growth in regional towns still does not fully explain why some towns grow large and others stay small and there is a need to further explore these issues. The extreme skewness in population and enterprise numbers of different towns' distributions should, however, be considered in local economic development planning and execution. SIGNIFICANCE: • This contribution illustrates that the populations and enterprises of South African regional towns are distributed in orderly ways (called Pareto distributions) that result in some being large/many and others small/few. <![CDATA[<b>Arable agriculture changes soil microbial communities in the South African Grassland Biome</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S0038-23532018000300016&lng=es&nrm=iso&tlng=es Many studies, mostly in temperate regions of the northern hemisphere, have demonstrated that agricultural practices affect the composition and diversity of soil microbial communities. However, very little is known about the impact of agriculture on the microbial communities in other regions of the world, most particularly on the African continent. In this study, we used MiSeq amplicon sequencing of bacterial 16S rRNA genes and fungal ITS regions to characterise microbial communities in agricultural and natural grassland soils located in the Mpumalanga Province of South Africa. Nine soil chemical parameters were also measured to evaluate the effects of edaphic factors on microbial community diversity. Bacterial and fungal communities were significantly richer and more diverse in natural grassland than in agricultural soils. Microbial taxonomic composition was also significantly different between the two habitat types. The phylum Acidobacteria was significantly more abundant in natural grassland than in agricultural soils, while Actinobacteria and the family Nectriaceae showed the opposite pattern. Soil pH and phosphorus significantly influenced bacterial communities, whereas phosphorus and calcium influenced fungal communities. These findings may be interpreted as a negative impact of land-use change on soil microbial diversity and composition. SIGNIFICANCE: • This report is the first of the effect of land-use changes on the diversity of the soil microbial communities in African grassland soils. • Land-use changes influence the diversity and structure of soil microbial communities in the Grassland Biome of South Africa. • This study serves as a baseline for future studies on South African soil microbial diversity.