1834 research outputs found
Sort by
Nexus : current & completed research projects new shared workflow proposal for HEIs and the NRF
No full textAt present the Nexus database provides information on approximately 170 000 South African Current and Completed Research Projects, the latter linked to the Electronic Theses and Dissertations Portal which harvests from higher education institutional repositories. This knowledge resource provides information on all fields of science since 1919. The records of the Union Catalogue of Theses and Dissertations (UCTD) formerly maintained by the Potchefstroom University for CHE are now included as per stakeholder request. The NAVTECH research projects are included in the database. Nexus also includes abstracts and English titles for research projects not in English. This database is widely used by local and international researchers and students
The growth and recovery of mangroves at three South African study sites
No full textMangroves in South Africa are prone to anthropogenic pressures such as browsing and trampling by livestock and by natural disturbances such as drought and floods. These mangroves exist at one of the most southerly limits in the world providing a unique opportunity to study recovery and resilience to change. This study used long term data at three South African study sites located in the subtropical (St Lucia Estuary) and warm temperate regions (Nxaxo and Kobonqaba estuaries) to compare mangrove growth rate, population structure and responses to disturbance. The first objective was investigated at St Lucia Estuary where site specific or microhabitat differences were measured to assess the influence of these on mangrove growth and population structure. It was suggested that site - specific variability would ensure mangrove survival and analysis showed that seedlings were present at different sites in different years. There was always some recruitment but often little survival to the next size class. Over time seedling numbers were quite variable and self – thinning of adults was evident. The second objective was to identify the environmental factors influencing population density and growth. Results showed that sediment moisture and salinity influenced seedling and adult density due to fluctuations in estuary water level. Mangrove growth rates for Avicennia marina in terms of height was faster (40 – 75 cm yr-1 ) at Site 1 where conditions were waterlogged and moderately saline and slower (5 – 25 cm yr1 ) in dry and hypersaline conditions at Site 4. Overall mangroves at St Lucia have shown persistence through drought and fluctuations in environmental conditions however resilience may be hindered at sites that are subjected to partially flooding and prolonged waterlogging. The second site was Nxaxo Estuary in the Eastern Cape where cattle exclusion plots (nonbrowsed) and control plots (browsed) were used to assess the recovery of A. marina trees from cattle browsing. Trees in the browsed plots showed no vertical growth while trees in the non-browsed plots grew significantly faster (5.4 ± 0.5 cm yr-1). When cattle were prevented from entering the mangrove area, the trees recovered fairly quickly and within 3 years growth was similar in both the non – browsed (17.9 ± 3.2 cm yr -1) and browsed plots (18 ± 1.6 cm yr -1). Lastly, mangrove recovery was investigated at Kobonqaba Estuary where long-term closure of the mouth to the sea resulted in high water levels, inundation of pneumatophores and die-back of the majority of the mangroves. This study measured the recovery of the mangroves by assessing changes in vegetation cover and sediment characteristics along transects. High initial porewater nutrient concentrations promoted salt marsh growth and plants increased average cover from 0% in 2011 to 18.9% (2013) and 50% in 2015. The total number of A. marina individuals increased from only seven to 27 individuals over four years. Salt marsh competition and facilitation will likely influence mangrove recovery in the future. Overall it was concluded that when a short term pressure (cattle browsing) is alleviated, mangrove forests even at warm temperate sites are able to recovery rapidly by increasing growth and seedling establishment. However, mangroves in the subtropical sites show more resilience and recovery potential to long term pressures such as fluctuating environmental conditions because of faster growth rates.National Research Foundatio
Reviews, Evaluations & Projects (REP) Breakaway Session (RAW) 2017
No full textThe Grants Management and Systems Administration (GMSA) Directorate hosted its 8th annual Research Administrators Workshop (RAW) from 9 to 11 October 2017 in the Western Cape. The workshop aimed to bring together key stakeholders from universities and science councils across South Africa, including international delegates, to share experiences and best practices in research administration and management
The second Southern African bird atlas project: causes and consequences of geographical sampling bias
No full textUsing the Southern African Bird Atlas Project (SABAP2) as a case study, we examine the possible determinants of spatial bias in volunteer sampling effort and how well such biased data represent environmental gradients across the area covered by the atlas. For each province in South Africa, we used generalized linear mixed models to determine the combination of variables that explain spatial variation in sampling effort (number of visits per 5′ × 5′ grid cell, or “pentad”). The explanatory variables were distance to major road and exceptional birding locations or “sampling hubs,” percent-age cover of protected, urban, and cultivated area, and the climate variables mean annual precipitation, winter temperatures, and summer temperatures. Further, we used the climate variables and plant biomes to define subsets of pentads representing environmental zones across South Africa, Lesotho, and Swaziland. For each environ-mental zone, we quantified sampling intensity, and we assessed sampling complete-ness with species accumulation curves fitted to the asymptotic Lomolino model. Sampling effort was highest close to sampling hubs, major roads, urban areas, and protected areas. Cultivated area and the climate variables were less important. Further, environmental zones were not evenly represented by current data and the zones var-ied in the amount of sampling required representing the species that are present. SABAP2 volunteers’ preferences in birding locations cause spatial bias in the dataset that should be taken into account when analyzing these data. Large parts of South Africa remain underrepresented, which may restrict the kind of ecological questions that may be addressed. However, sampling bias may be improved by directing volun-teers toward undersampled regions while taking into account volunteer preferences.National Research Foundation, Grant/Award Number: 88121, 85802, 81685 and 7391
An exploration of the potential of wordless picturebooks to encourage parent-child reading in the South African context
No full textThis research study focused on the influence of a participatory project in which wordless
picturebooks were used in parent-child joint reading and, more generally, the development
of a culture of reading in the home. The research was conducted within the South African
context, in low socio-economic areas of Gauteng, and is approached from the researcher’s
viewpoint as an illustrator. Using multimodal social semiotics as a theoretical departure,
the researcher argues that the characteristics of wordless picturebooks can serve as
motivating factors that could contribute to developing a more positive attitude to reading
in South Africa.
Internationally, there is a large volume of literature which advocates the use of wordless
books in literacy development, yet little research exists on their use in the South African
context. Furthermore, the majority of research investigating the value of book sharing has
been conducted in the developed world. South Africa has a very low general reading rate,
and despite a growing support for literacy development in mother tongue, there still exists
a lack of indigenous language picturebooks for very young children. Many families are also
simply unable to afford books. As a result, many children are not exposed to books or book
sharing activities prior to entering formal school, where the focus of reading is not on
reading for enjoyment. By systematically moving the reading environment from a
community center or pre-school to participant homes, the main aim of this research was
to determine the perceptions of the parents /primary caregivers and children that
participated in the research regarding the value of utilizing wordless picturebooks. The
researcher aimed go gain an understanding of how wordless picturebooks could assist in
ensuring that literacy poor families are supported as a child’s first educator.
The research was based on participative action research, and was conducted in three
literacy poor areas of Gauteng. Qualitative data was collected by means of focus group and
semi-structured individual interviews before and after participants attended a reading
programme that spanned over a four to six-week period. Prior to the reading programme,
a story collection workshop was hosted at two of the research sites, and the stories
collected from the participants was used by the researcher to create wordless
picturebooks. The use of these books were subsequently pilot tested at the third research
site, whereas existing wordless picture books were used at the first two sites. An initial sample of 42 parents/primary caregivers and their pre-school child were included in the
study, however low participant retention resulted in a significantly smaller sample that
completed the research with only 14 parents/primary caregivers having attended all the
sessions of the reading programme. It should however be noted that even though the
number of participants that completed the entire programme, in other words, who
attended all sessions, was low, data pertaining to the reading experience after the
implementation of the programme was collected from 39 participants in total.
Thematic analysis of the data was conducted, and themes that pertained to aspects of
Design (as a central notion in Multiliteracies), Multimodality and participant generated
content were identified. The key findings indicated that wordless picturebooks can be
viewed as a valuable tool in fostering a culture of reading in the South African context.
Participants reported that they were reading more at home, and that the activity was
enjoyable, compared to previous reading experiences. Furthermore, the research findings
highlighted factors that influence parent-child reading programmes within the context of
South African, literacy poor areas. It is recommended the genre warrants more local
attention and that larger-scale research studies be conducted with more diverse
populations.National Research Foundatio
Modelling South African traffic for large networks - an extension of the gravity model for traffic demand modelling
No full textTraffic congestion is a growing burden on society. Due to the complexity of modelling transportation,
many approaches do not scale efficiently. Assumptions are made to estimate the
locality and quantity of traffic that passes through, leaves or enters a study area. Infrastructure
investment based on inaccurate transportation modelling could potentially increase congestion.
Furthermore, the effects of changes in infrastructure outside a study area are also unknown. It
is therefore necessary to model transportation networks at a larger scale than required before.
This thesis presents a large scale traffic modelling framework, potentially capable of modelling
the impact of public transport and infrastructure investment for the South African context. The
framework builds on the basic procedure of the Four-Step Modelling methodology.
To address the shortcomings of static trip distribution models, a proposed, temporally adjusted,
doubly constrained gravity model is formulated. Kernel density functions are fitted from survey
data to define unique impedance of travel functions for each travel analysis zone. Route selection
is determined by a heuristic approach to dynamic traffic assignment which is implemented in a
mesoscopic traffic simulator.
The proposed gravity model is iteratively calibrated using the output of the traffic simulator in a
positive feedback loop to produce a trip distribution that approaches an equilibrium assignment.
The gravity model calibration and validation shows that the proposed gravity model is more
accurate than the single impedance of travel gravity model. The framework produces OD trip
matrices, inter- and intra-zonal routes, quarter-hourly traffic flows and a measure of congestion,
all which can be visualised in a GIS environment.National Research Foundatio
A framework for implementing bring your own device in higher education institutions in South Africa
No full textAlthough the concept of Bring Your Own Device (BYOD) was only first introduced in 2009, organisations and higher education institutions have shown an increasing interest in and tolerance for employees and students using their own mobile devices for work and academic purposes, to such an extent that it is predicted that BYOD will become the leading practice for all educational environments by the year 2017. Although mobile device usage is increasing in higher education institutions, it has been found that currently no generally recognised framework exists to aid South African higher education institutions with the implementation of BYOD. The problem is further worsened as research suggests that the number of new mobile vulnerabilities reported each year has increased. The primary objective of this study is to develop a framework for implementing BYOD in higher education institutions in South Africa. This primary objective is divided into several secondary objectives, which collectively aim to address the proposed problem. Therefore, the secondary objectives are to understand BYOD in organisations and the challenges it brings; to determine how BYOD challenges differ in higher education institutions; to determine the key components for implementing BYOD in higher education institutions; to determine the extent to which the BYOD key components relate to a higher education institution in South Africa; and to validate the proposed BYOD framework, verifying its quality, efficacy and utility. At first, a comprehensive literature study is used to determine and understand the benefits, challenges and key components for the implementation of BYOD in both organisations and higher education institutions. Thereafter, a case study is used to determine the extent to which the components, identified in the literature study, relate to an educational institution in South Africa. The findings from the case study, in combination with the key components, are then triangulated and a preliminary framework for implementing BYOD in higher education institutions in South Africa is argued. Furthermore, elite interviews are used to determine the quality, efficacy and utility of the proposed BYOD framework. To address the proposed problem, this research proposes a stepby- step holistic framework to aid South African higher education institutions with the implementation of BYOD. This framework adds a significant contribution to the work on this topic, as it provides a foundation upon which further such research can build. It is believed that such a framework would be useful for higher education institutions in South Africa and would result in the improved implementation of BYOD.National Research Foundatio
A corpus-based analysis of code-switching in the oral discourse of Shona-English bilinguals
No full textBilingualism is one of the by-products of globalization and migration. As people from different ethnicities come into contact, their languages will influence each other. People learn a second or third language in different environments leading to their linguistic proficiency levels being different. In conversations involving bilinguals, code-switching may be prevalent. This practise of alternating between two or more languages during a speech act has been of great interest to researchers with various models and hypotheses being proposed to explain it. Although code-switching has been studied extensively in literature, indigenous languages such as Shona have received less attention. This study aims to determine whether the markedness model of code-switching can be applied to Shona oral discourse (speech). An analysis is done to ascertain the nature, occurrence and characteristics of code-switching in the speech of Shona-English bilinguals. Participants who attended formal education for at least ten years were selected for the study. In order to inform on the theoretical background and on previous studies that dealt with code-switching, a literature review was conducted. The study used semi-structured interviews, a cloze test and recordings as data collection methods. Data was analysed to determine the applicability of the markedness model to the compiled corpus. Data analysis was also aided by WordSmith, (corpus analysis software). Results of the analysis seem to suggest that the markedness model can be applied to Shona-English code-switching. In addition, an analysis of the corpus using WordSmith showed frequently used English words and collocations and concordances of the code-switched words. An examination of the collocations and concordances shows the contexts in which the code-switched words appear.National Research Foundatio
The impact of EPHA2 polymorphism on KSHV infectivity and KS prevalence among HIV/AIDS patients in South Africa
No full textKaposi's Sarcoma (KS) is the most common Acquired Immune Deficiency Syndrome (AIDS)-related malignancy globally and is of particular significance in sub-Saharan Africa where, due to the Human Immunodeficiency Virus (HIV) epidemic, KS is the cause of significant morbidity and mortality. The oncogenic Kaposi's Sarcoma-associated herpes virus (KSHV) is the etiological agent of KS. Although KSHV seroprevalence in sub-Saharan Africa is high, not all AIDS patients develop KS, suggesting that host genetic factors contribute to susceptibility. The infection mechanism of KSHV in endothelial cells has recently been elucidated and highlights Eph Receptor A2 (EPHA2) as a specific host receptor for virus entry. Furthermore, EPHA2 has been implicated in oncogenesis and is upregulated in a number of cancers including KS. We therefore hypothesised that mutations in the KSHV host receptor's coding region could result in an altered EPHA2 that could affect susceptibility to KSHV infection and/or KS development among HIV/AIDS patients. To test our hypothesis, we studied three groups of HIV positive South African patients, namely patients with KS and patients without KS who were KSHV positive or KSHV negative. KS status was determined clinically and KSHV seroconversion was assessed using a combination of ELISAs to KSHV lytic antigen K8.1 and latency-associated nuclear antigen in patient plasma samples. All patients with KS were found to be KSHV seropositive as expected, while 45.45% of HIV positive patients without KS were found to be KSHV seropositive. From patient blood cells, we extracted genomic DNA and subsequently PCR amplified and sequenced the coding region of EPHA2, before comparing these sequences to the NCBI reference by multiple alignment. A number of variants were identified throughout the EPHA2 coding region and assessed statistically for association with KSHV susceptibility and/or KS prevalence. A novel heterozygous transition (c.2727C>T), which is predicted to result in the substitution of Cysteine for Arginine at amino acid position 858 in the functionally important tyrosine kinase domain, was identified as statistically associated with KSHV susceptibility as well as KS prevalence. Three additional missense variants (c.2254T>C, c.2257A>C and c.2688G>C) occurring in the tyrosine kinase domain and one occurring in the sterile-α-motif (c.2990G>T), a putative protein interaction domain, were found to be statistically associated with KS prevalence. This is the first study to investigate polymorphism in EPHA2 in HIV/AIDS patients in relation to susceptibility to KSHV infection and/or KS prevalence. The identification of variants in the KSHV entry receptor, EPHA2, opens new doors for the development of biomarkers involved in prognosis and treatment of KSHV-associated pathologies.National Research Foundatio