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Electron spin resonance dating of tooth enamel from Kromdraai B, South Africa

Curnoe, Darren; Grun, Rainer; Thackeray, J
Fonte: Academy of Science of South Africa Publicador: Academy of Science of South Africa
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
86.24%
ELECTRON SPIN RESONANCE (ESR) DATING offers the potential to provide dates for Plio-Pleistocene sites in South Africa. Previous attempts have been made to date tooth enamel samples from Sterkfontein, Swartkrans and Gladysvale. Here we report results of ESR dating of tooth enamel from Kromdraai B in the Sterkfontein Valley.

Timing and kinematics of the Colenso Fault: The early Paleozoic shift from collisional to extensional tectonics in the Pan-African Saldania Belt, South Africa

Kisters, Alexander F M; Belcher, Richard W; Armstrong, Richard; Scheepers, Reyno; Rozendaal, Abraham; Jordaan, L Smith
Fonte: Geological Society of South Africa Publicador: Geological Society of South Africa
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
86.24%
The Colenso fault is a major northwest to southeast trending fault zone in the Pan-African Saldania Belt of the Western Cape Province in South Africa that is spatially closely associated with granitoids of the ∼550 to 510 Ma Cape Granite Suite. Most of

Age and significance of the Marble Hall breccia, Bushveld Complex, South Africa

De Waal, S.A.; Graham, IT; Phillips, David
Fonte: Geological Society of South Africa Publicador: Geological Society of South Africa
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
86.24%
Diorite and associated breccia form scattered outcrops on the Marble Hall Fragment, in the vicinity of the town of Marble Hall, Mpumalanga Province, South Africa. The diorite (2055.6 ± 3.1 Ma) intruded as sub-horizontal sills in highly deformed and metam

Pleistocene Homo and the updated Stone Age sequence of South Africa

Dusseldor,Gerrit; Lombard,Marlize; Wurz,Sarah
Fonte: South African Journal of Science Publicador: South African Journal of Science
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2013 Português
Relevância na Pesquisa
76.32%
We provide a brief overview of how the rich South African Pleistocene Homo fossil record correlates with the recently revised Stone Age sequence. The overview and correlation of the data is intended to highlight gaps in the record and/or our understanding thereof, and to stimulate interdisciplinary research and debate on the Homo fossil and archaeological records spanning the Pleistocene. As an updated resource we present a complete inventory of known Pleistocene fossil material assigned to the genus Homo, and, where possible, its association with archaeological material. We demonstrate that (1) anatomical changes are not necessarily paralleled by changes in the archaeological sequence currently based on a range of technocomplexes, (2) the early Homo record of South Africa probably differs from that of East Africa, (3) mid-Pleistocene Homo might be associated with the Earlier to Middle Stone Age transitional phase and (4) the fossil record associated with the Middle Stone Age has wide anatomical variation. Also, hiatuses in the fossil record, such as that associated with the appearance of early Khoe-San-like populations, do not show concurrent hiatuses in the archaeological record. Thus, for a broader understanding of the demographic history of South Africa during the Pleistocene...

A serological survey of antibodies to Leptospira species in dogs in South Africa

Roach,J M; van Vuuren,M; Picard,J A
Fonte: Journal of the South African Veterinary Association Publicador: Journal of the South African Veterinary Association
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/09/2010 Português
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76.36%
Leptospirosis, a disease more common in the tropics, can cause a life-threatening multisystemic syndrome in humans and animals. Immunity, whether natural or vaccineinduced, is serogroup-specific with the infecting serovars varying according to geographical locality. In South Africa, in spite of the fact that the bacterin vaccine for some Leptospira serovars is often used, there is no recent information on the incidence of canine leptospirosis as well as the infecting serovar/s. The aim of this study, which was undertaken on sera collected in 2008 and 2009 from both strays and owned dogs predominantly in the coastal regions of South Africa, was to determine the presence of leptospiral antibodies to 15 serovars known to infect dogs. Of the 530 samples tested, 25 tested positive to 7 different serovars with the microscopic agglutination test (MAT). Nine of the 25 samples tested positive to more than one serovar. The 2 serovars most frequently represented were Canicola, which reacted to 17 sera, and Pyrogenes, which reacted to 10 sera. Currently the only vaccines available in South Africa in different combinations contain serovars Canicola, Icterohaemorrhagiae, Pomona and Grippotyphosa. The results showed that the use of vaccines containing serovar Canicola is still justifiable in certain regions of the country. However...

Contextualizing South Africa's participation in the SITES 2006 module

Blignaut,Seugnet; Els,Christo; Howie,Sarah
Fonte: South African Journal of Education Publicador: South African Journal of Education
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2010 Português
Relevância na Pesquisa
76.33%
The International Association for the Evaluation of Educational Achievement (IEA) initiated the Second International Technology in Education Study (SITES 2006) - a large-scale comparative survey on the use of Information and Communication Technologies (ICTs) in schools. The goal was to understand the pedagogical use of ICTs in schools in 22 education systems. We aim to contextualize South Africa's participation in SITES 2006 on four levels: (i) the nature and structure of the South African education system, (ii) a review of South Africa's participation in SITES 2006, (iii) ICT infrastructure, facilities and equipment, and (iv) teachers' use of ICTs for teaching and learning. SITES 2006 administered three questionnaires to school principals, technology coordinators, and mathematics and science teachers. The final sample consisted of 666 mathematics and 622 science teachers. Although most education systems collected data via the internet, South Africa was the only country that used only a paper-and-pencil data collection strategy with an average return rate of 90%. South Africa scored low on most variables, e.g. ICT infrastructure, facilities, and equipment. A large percentage of South African teachers reported their ICT incompetence. South Africa's inability to cross the boundaries of traditional learning towards the development of 21st century teaching and learning skills inhibits social and economic growth for the development of human capital.

Technical efficiency and primary education in South Africa: evidence from sub-national level analyses

Boateng,Nana Adowaa
Fonte: South African Journal of Education Publicador: South African Journal of Education
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/06/2014 Português
Relevância na Pesquisa
76.32%
The paper examines the extent to which sub-national public officials are efficient in delivering basic education services and argues that technical inefficiencies, especially in the management of public funds for education, could potentially contribute to poor education service delivery in South Africa. A conceptual framework is proposed to show the underlying mechanisms by which these technical inefficiencies can adversely affect education outcomes. The analysis is based on two micro-level surveys that were applied at 175 public primary schools and 13 district education offices (DEOs) in two provinces in South Africa: the North-West Province and Gauteng. The analysis reveals that South Africa has a well-planned decentralised structure to administer education. However, districts have significant human resource constraints. Capacity is often lacking and record-keeping, particularly of financial information, is very poor. Lack of technical efficiency has resulted in misappropriation of funds (leakage) and extensive delays in remitting funds to schools. The paper concludes that these inefficiencies potentially affect education outcomes and therefore should be given due consideration when designing and implementing education policy reforms.

Renewable energy choices and their water requirements in South Africa

Sparks,Debbie; Madhlopa,Amos; Keen,Samantha; Moorlach,Mascha; Dane,Anthony; Krog,Pieter; Dlamini,Thuli
Fonte: Journal of Energy in Southern Africa Publicador: Journal of Energy in Southern Africa
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/11/2014 Português
Relevância na Pesquisa
76.32%
South Africa is an arid country, where water supply is often obtained from a distant source. There is increasing pressure on the limited water resources due to economic and population growth, with a concomitant increase in the energy requirement for water production. This problem will be exacerbated by the onset of climate change. Recently, there have been concerns about negative impacts arising from the exploitation of energy resources. In particular, the burning of fossil fuels is significantly contributing to climate change through the emission of carbon dioxide, a major greenhouse gas. In addition, fossil fuels are being depleted, and contributing to decreased energy security. As a result of this, the international community has initiated various interventions, including the transformation of policy and regulatory instruments, to promote sustainable energy. With this in mind, South Africa is making policy and regulatory shifts in line with international developments. Renewable energy is being promoted as one way of achieving sustainable energy provision in the country. However, some issues require scrutiny in order to understand the water footprint of renewable energy production. Due to the large gap that exists between water supply and demand...

What contribution does the installation of solar water heaters make towards the alleviation of energy poverty in South Africa?

Wlokas,Holle Linnea
Fonte: Journal of Energy in Southern Africa Publicador: Journal of Energy in Southern Africa
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2011 Português
Relevância na Pesquisa
76.34%
The South African government has publicized plans to install one million solar water heaters in households throughout South Africa by the year 2014, with the goals of reducing strain on existing electricity resources, mitigating greenhouse gas emissions, creating employment and alleviating poverty. This paper examines two existing solar water heater installation projects with the aim of investigating the social contribution of the installation of solar water heaters in low-income households in South Africa. The Sustainable Urban Livelihoods approach (SULA) was adjusted to provide an analytical framework for the development of suitable indicators of social change in the context of renewable energies and energy poverty. Increases in household capital and the reduction of household vulnerability to shocks, stressors and seasonal variability as the result of solar water heater installation were investigated in projects in low-income housing developments in the cities of Cape Town and Port Elizabeth, South Africa. Data collected from paired household surveys (before and after installation) in over 600 households and qualitative information (Most Significant Change stories) show that the provision of a constant, cheap source of heated water contributed positively to the alleviation of energy poverty. Household capitals (categorised as Human...

Dissemination of solar water heaters in South Africa

Chang,Keh-Chin; Lin,Wei-Min; Ross,Greg; Chung,Kung-Ming
Fonte: Journal of Energy in Southern Africa Publicador: Journal of Energy in Southern Africa
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2011 Português
Relevância na Pesquisa
76.39%
Global concern over a looming energy crisis, water scarcity and man-made climate change are driving a huge demand for clean technologies, which focus on preserving the earth's resources. In South Africa, the economy is very energy-intensive with coal being the main national energy supply. In view of the growing depletion of fossil fuel, it is important for South Africa to adopt a more sustainable energy mix. This study examines the potential for widespread dissemination of solar water heaters (SWHs) in South Africa. Barriers and constraints to market expansion are analyzed to determine strategies for overcoming these barriers. It is found that payback period of a SWH is shorter than the life-span of the system itself, indicating that SWHs are economically viable even with low production cost of electricity and thus represent a profitable investment proposition for end users, manufacturers and distributors. However, the subsidy programs offered by the government of South Africa may not be sufficient to facilitate diffusion. This is attributed to the high initial capital cost of the system and low affordability of the majority of the South Africa population with low income. Alternative financing mechanisms are required.

Recent advances in sex identification of human skeletal remains in South Africa

Bidmos,MA; Gibbon,VE; Štrkalj,G
Fonte: South African Journal of Science Publicador: South African Journal of Science
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/12/2010 Português
Relevância na Pesquisa
76.34%
We review methods of sex estimation from human skeletal remains in South Africa within the forensic context. Sex is one of the key variables in obtaining a biological profile of the individual or population whose remains are analysed. Sex estimation based on the morphological characteristics of skeletal elements is population specific and thus the establishment of regional criteria is one of the imperatives for modern forensic anthropology. A literature review was carried out wherein the available methods of sex identification (morphological, metrical, geometric morphometrics and molecular) from South African skeletal material were critically examined. The approaches to sex estimation based on bone morphology have a long and productive history in South Africa. A number of approaches providing accurate results on the local populations have been developed. Research in molecular sex determination methods is still in its infancy in South Africa and the first innovative studies appeared only in recent years. While each of the four methods analysed is bounded by a number of constraints, they seem to complement each other and provide the best results when applied in conjunction with each other.

Economic inequality as a source of interpersonal violence: Evidence from Sub-Saharan Africa and South Africa

Harris,Geoff; Vermaak,Claire
Fonte: South African Journal of Economic and Management Sciences Publicador: South African Journal of Economic and Management Sciences
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2015 Português
Relevância na Pesquisa
76.32%
This article examines whether the close association of income inequality and violence identified for high income countries applies also to sub-Saharan Africa and, in particular, to South Africa. Cross sectional analysis across sub-Saharan countries provided no evidence of such an association. However, using homicide rates and several measures of inequality across South Africa's 52 districts does provide evidence of a significant positive relationship between homicide rates and expenditure inequality. A one per cent increase in inequality is associated with an increase in the homicide rate of 2.3 to 2.5 per cent. This relationship remains significant after controlling for other characteristics of the district.

Cradle-to-gate environmental impacts of the concrete industry in South Africa

Muigai,R; Alexander,M G; Moyo,P
Fonte: Journal of the South African Institution of Civil Engineering Publicador: Journal of the South African Institution of Civil Engineering
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2013 Português
Relevância na Pesquisa
76.34%
The objective of the paper is to provide an understanding of the South African concrete industry's environmental burden in terms of natural resource consumption and carbon dioxide equivalent emissions (CO2-e). The review covers current practices in the concrete construction field in South Africa (SA) and their implications for the environment. Elaboration in terms of detail and quantification is given for the environmental burden generated during the manufacture of raw materials for concrete and their transportation to site. Four-year average (2005-2008) data is provided for resources consumed and wastes emitted during the quarrying and manufacture of raw materials for concrete. Carbon dioxide-equivalent emissions data per unit of material produced was obtained from the InEnergy Report produced for the Cement and Concrete Institute (C&CI) of South Africa. The study determined that, on average, 39.7 Mt of raw materials are consumed per year and 4.92 x 10(9) kg CO2-e emissions are emitted per year to produce cement and aggregates for concrete production in South Africa.

Strong winds in South Africa: Part 1 Application of estimation methods

Kruger,A C; Retief,J V; Goliger,A M
Fonte: Journal of the South African Institution of Civil Engineering Publicador: Journal of the South African Institution of Civil Engineering
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2013 Português
Relevância na Pesquisa
76.36%
The accurate estimation of strong winds is of cardinal importance to the built environment, particularly in South Africa, where wind loading represents the dominant environmental action to be considered in the design of structures. While the Gumbel method remains the most popular applied method to estimate strong wind quantiles, several factors should influence the consideration of alternative approaches. In South Africa, the most important factors influencing the choice of method are the mixed strong wind climate and the lengths of available wind measurement records. In addition, the time-scale of the estimations (in this case one hour and 2-3 seconds) influences the suitability of some methods. The strong wind climate is dominated by synoptic scale disturbances along the coast and adjacent interior, and mesoscale systems, i.e. thunderstorms, in the biggest part of the interior. However, in a large part of South Africa more than one mechanism plays a significant role in the development of strong winds. For these regions the application of a mixed-climate approach is recommended as more appropriate than the Gumbel method. In South Africa, reliable wind records are in most cases shorter than 20 years, which makes the application of a method developed for short time series advisable. In addition it is also recommended that the shape parameter be set to zero...

The scholarly impact of doctoral research conducted in the field of education in South Africa

Wolhuter,CC
Fonte: South African Journal of Education Publicador: South African Journal of Education
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/08/2015 Português
Relevância na Pesquisa
76.36%
The aim of this study is to investigate the scholarly impact of knowledge generated as part of doctoral studies in the field of education in South Africa. The transition rate of the 97 doctoral theses completed in the various fields of education in South Africa in 2008 into peer-reviewed articles and chapters in scholarly books, as well as the citation impact of these theses, were studied. It was found that the transition rates of these theses to journal articles and book chapters were low, as was their citation impact. Eighty three of the 97 theses did not transfer into any kind of publication, 70 out of the 97 made no citation impact, and 65 theses neither transferred to an article/a book chapter, nor did they receive any citation. The low scholarly impact of doctoral research in education in South Africa is related to a number of contextual and field-specific factors, identified in the survey of literature. The main recommendation made is the mapping of fields of education scholarship, making possible the identification of lacuna for research with high impact potential.

Decomposition analysis of energy-related CO2 emissions in South Africa

Zhang,Ming; Dai,Shuang; Song,Yan
Fonte: Journal of Energy in Southern Africa Publicador: Journal of Energy in Southern Africa
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/02/2015 Português
Relevância na Pesquisa
76.32%
South Africa has become one of the most developing countries in the world, and its economic growth has occurred along with rising energy-related CO2 emission levels. A deeper understanding of the driving forces governing energy-related CO2 emissions is very important in formulating future policies. The LMDI (Log Mean Divisia Index) method is used to analyse the contribution of the factors which influence energy-related CO2 emissions in South Africa over the period 1993-2011. The main conclusions drawn from the present study may be summarized as follows: the energy intensity effect plays the dominant role in decreasing of CO2 emission, followed by fossil energy structure effect and renewable energy structure effect; the economic activity is a critical factor in the growth of energy-related CO2 emission in South Africa.

Public attitudes to science in South Africa

Reddy,Vijay; Gastrow,Michael; Juan,Andrea; Roberts,Benjamin
Fonte: South African Journal of Science Publicador: South African Journal of Science
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2013 Português
Relevância na Pesquisa
76.32%
In a global environment characterised by the growing role of science and technology in our economic, social, and political lives, an international research agenda has arisen to measure and understand how science and technology are perceived and evaluated by the public. In 2010, the South African Social Attitudes Survey included 20 items to measure public attitudes towards science, knowledge about science, and sources of information about science. This household survey was administered to a representative, stratified, random sample of 3183 participants. The findings were analysed through a bivariate analysis, and here we report on South African attitudes towards science and technology, how these have changed between 1999 and 2010, and where South African science attitudes fit on the canvas of global science attitudes. The data reveal a complex and shifting relationship between attitudes of promise and reservation towards science in South Africa. In the international context, South Africa has a unique 'fingerprint' of public attitudes towards science. The strongest demographic variable impacting on attitude towards science was educational attainment, followed by age. Gender had no impact on science attitude. This broad overview also highlights some directions for further research to meet the growing academic and policy interest in the interface between the institutions of science and the public.

Self-reported musculoskeletal pain among dentists in South Africa: A 12-month prevalence study

Botha,PJ; Chikte,U; Barrie,R; Esterhuizen,TM
Fonte: SciELO África do Sul Publicador: SciELO África do Sul
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em // Português
Relevância na Pesquisa
76.38%
INTRODUCTION: Musculoskeletal trouble (ache, pain, discomfort) originating in the neck, shoulder, and back is a common occupational hazard among dental professionals worldwide. The significance of this problem justified research into the prevalence of these symptoms among dentists in South Africa for which there is currently no information. AIMS: The aim of this study was to investigate the one-year prevalence of self-reported musculoskeletal trouble in the neck, shoulder, and lower back areas among dentists in South Africa. METHODS: A survey questionnaire was forwarded to all members of the South African Dental Association whose email addresses were recorded on the Association data base. The email survey was performed using the previously validated Nordic Musculoskeletal Questionnaires. RESULTS: This cross sectional study revealed a self-reported 12-month prevalence of musculoskeletal trouble (ache, pain, discomfort) among dentists in South Africa of 77,9% involving the neck, 69,8% the lower back, and 72,4% the shoulders. Multiple regression analysis showed that a decrease in height among the respondents was associated with an increase in neck trouble (0.962 [CI 0.938; 0.992]). CONCLUSIONS: The 12-month prevalences for musculoskeletal trouble (ache...

Greenhouse gas emissions from shale gas and coal for electricity generation in South Africa

Cohen,Brett; Winkler,Harald
Fonte: South African Journal of Science Publicador: South African Journal of Science
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/02/2014 Português
Relevância na Pesquisa
76.32%
There is increased interest, both in South Africa and globally, in the use of shale gas for electricity and energy supply. The exploitation of shale gas is, however, not without controversy, because of the reported environmental impacts associated with its extraction. The focus of this article is on the greenhouse gas footprint of shale gas, which some literature suggests may be higher than what would have been expected as a consequence of the contribution of fugitive emissions during extraction, processing and transport. Based on some studies, it has been suggested that life-cycle emissions may be higher than those from coal-fired power. Here we review a number of studies and analyse the data to provide a view of the likely greenhouse gas emissions from producing electricity from shale gas, and compare these emissions to those of coal-fired power in South Africa. Consideration was given to critical assumptions that determine the relative performance of the two sources of feedstock for generating electricity - that is the global warming potential of methane and the extent of fugitive emissions. The present analysis suggests that a 100-year time horizon is appropriate in analysis related to climate change, over which period the relative contribution is lower than for shorter periods. The purpose is to limit temperature increase in the long term and the choice of metric should be appropriate. The analysis indicates that...

Scientific research in the natural sciences in South Africa: A scientometric study

Sooryamoorthy,Radhamany
Fonte: South African Journal of Science Publicador: South African Journal of Science
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2013 Português
Relevância na Pesquisa
76.34%
As a leading producer of scientific publications on the African continent, South Africa has made remarkable progress. However, attempts are yet to be made to comprehend the empirical reality of scientific production in South Africa. One way to do this is to analyse specific science disciplines (such as the natural sciences), publication outputs and their features. A bibliometric study was undertaken of the publication trends and patterns of South African researchers in the natural sciences from 1975 to 2005 (choosing selected sample years), using the Thomson Reuters' Web of Knowledge database of selected indexed natural science journals. Characteristics of natural science publications, such as the trends over the years, were revealed as well as the collaborative dimensions involved in the production of scientific papers in these disciplines in South Africa. The connection between collaboration and publication, as well as between collaboration and sectors of authors was evident. The key findings of this study were that authors were based mostly in universities and were collaborative in their research endeavours. In addition, the participation of international collaborators has increased.