78 research outputs found

    The impact of the European Union-South Africa free trade area agreement on factor returns in South Africa : much ado about nothing?

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    Includes bibliographical references (leaves 35-38)

    RADICAL SCAVENGING ACTIVITY OF SELECTED MEDICINAL PLANTS FROM LIMPOPO PROVINCE OF SOUTH AFRICA

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    Plants collected from Limpopo province of South Africa were investigated for their antioxidative potential using the DPPH radical scavenging assay. Acetone extracts of Flueggea virosa had the highest antioxidant activity with an IC50 value of 30 μg/ml, closely matching the ascorbic acid with an IC50 value of 25 μg/ml. The lowest antioxidant readings were observed with extracts of Rhynchosia venulosa (root extract) and Ficus ingens (leaf extract). Acetone extract of Bridelia virosa leaves had the highest phenolic content (156 mg GAE/g extract), while the lowest content was recorded for R. venulosa root extract and leaf extract of F. ingens (8.3 and 17.7 mg GAE/g extract, respectively). There was a linear correlation between antioxidant activity and total phenolic content. Extracts with high phenolic content had low IC50 values, while extracts with low phenolic concentrations had high IC50 values

    Thermodynamically accessible titanium clusters TiN, N = 2-32

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    We have performed a genetic algorithm search on the tight-binding interatomic potential energy surface (PES) for small TiN (N = 2-32) clusters. The low energy candidate clusters were further refined using density functional theory (DFT) calculations with the PBEsol exchange-correlation functional and evaluated with the PBEsol0 hybrid functional. The resulting clusters were analysed in terms of their structural features, growth mechanism and surface area. The results suggest a growth mechanism that is based on forming coordination centres by interpenetrating icosahedra, icositetrahedra and Frank-Kasper polyhedra. We identify centres of coordination, which act as centres of bulk nucleation in medium sized clusters and determine the morphological features of the cluster

    Collaborative custodianship through collaborative cloud mapping : challenges and opportunities

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    Collaborative custodianship refers to an arrangement where a number of custodians work together to produce integrated datasets for a spatial data infrastructure (SDI), e.g. local authorities contributing address or street data to a national SDI dataset. Collaborative cloud mapping allows for ubiquitous, convenient, on-demand, configured and tailor-made mapping with resources shared between various entities collaborating on a specific initiative, such as an SDI or for disaster management. This paper presents the results of a workshop in South Africa during which case studies from the Netherlands, Belgium and Austria of collaborative custodianship of address data were presented, and OpenStreetMap as a case study of collaborative cloud mapping. Subsequently, challenges and opportunities for implementing similar initiatives in the context of the South African SDI were debated in break-away sessions. The results from these sessions were analysed using the PESTEL framework

    Urban fuelwood demand and markets in a small town in South Africa: Livelihood vulnerability and alien plant control

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    Fuelwood is the primary energy for most households throughout the developing world. With increasing urbanization and declining local availability of fuelwood, a growing proportion of households obtain their fuelwood by purchasing it. These fuelwood markets are the key nexus in supply and demand scenarios and can be potentially significant points for intervention to address energy security amongst the urban poor. This paper reports on the fuelwood demand and marketing in a small town in South Africa. Despite the availability of more modern fuels and state subsidization of electricity, fuelwood was still used by half the households. Annual demand was 1.2 t per household. Over half of the households bought their fuelwood requirements because local stocks were limited. Those households that did collect their own fuelwood were significantly poorer than households that purchased fuelwood, as well as households that did not use fuelwood at all. Fuelwood markets operated through 45-60 vendors who transported fuelwood from further afield. Income from the fuelwood trade was low, but was strongly linked to hours worked. Thus, vendors working a full week did earn a meaningful income, especially in the context of high unemployment in the area. Fuelwood vendors also provided casual employment opportunities for unskilled labour. Most vendors harvested fuelwood from commonage lands, with most of the wood being from alien species. Local stocks of wood are declining in the face of constant transformation of commonage to residential areas, and a national water and biodiversity conservation programme to eradicate alien plants. This decline poses a threat to the financial viability of fuelwood markets. Yet, an opportunity exists to incorporate the vendors into the alien plant clearing programme, since they already perform such a function

    Distribution, drivers and population structure of the invasive alien snail Tarebia granifera in the Luvuvhu system, South Africa

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    Invasive alien species continue to spread and proliferate in waterways worldwide, but environmental drivers of invasion dynamics lack assessment. Knowledge gaps are pervasive in the Global South, where the frequent heavy human-modification of rivers provides high opportunity for invasion. In southern Africa, the spatio-temporal ecology of a widespread and high-impact invasive alien snail, Tarebia granifera, and its management status is understudied. Here, an ecological assessment was conducted at seven sites around Nandoni Reservoir on the Luvuvhu River in South Africa. The distribution and densities of T. granifera were mapped and the potential drivers of population structure were explored. T. granifera was widespread at sites impacted to varying extents due to anthropogenic activity, with densities exceeding 500 individuals per square meter at the most impacted areas. T. granifera predominantly preferred shallow and sandy environments, being significantly associated with sediment (i.e., chlorophyll-a, Mn, SOC, SOM) and water (i.e., pH, conductivity, TDS) variables. T. granifera seemed to exhibit two recruitment peaks in November and March, identified via size-based stock assessment. Sediment parameters (i.e., sediment organic matter, sediment organic carbon, manganese) and water chemistry (i.e., pH, total dissolved solids, conductivity) were found to be important in structuring T. granifera populations, with overall snail densities highest during the summer season. We provide important autecological information and insights on the distribution and extent of the spread of T. granifera. This may help in the development of invasive alien snail management action plans within the region, as well as modelling efforts to predict invasion patterns elsewhere based on environmental characteristics

    How do we best engage young people in decision-making about their health? A scoping review of deliberative priority setting methods

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    Abstract Introduction International organisations have called to increase young people’s involvement in healthcare and health policy development. We currently lack effective methods for facilitating meaningful engagement by young people in health-related decision-making. The purpose of this scoping review is to identify deliberative priority setting methods and explore the effectiveness of these in engaging young people in healthcare and health policy decision-making. Methods Seven databases were searched systematically, using MeSH and free text terms, for articles published in English before July 2021 that described the use of deliberative priority setting methods for health decision-making with young people. All titles, abstracts and full-text papers were screened by a team of six independent reviewers between them. Data extraction followed the Centre for Reviews and Dissemination guidelines. The results are presented as a narrative synthesis, structured around four components for evaluating deliberative processes: 1) representation and inclusion of diverse participants, 2) the way the process is run including levels and timing of participant engagement, 3) the quality of the information provided to participants and 4) resulting outcomes and decisions. Findings The search yielded 9 reviews and 21 studies. The more engaging deliberative priority setting tools involved young people-led committees, mixed methods for identifying and prioritising issues and digital data collection and communication tools. Long-term and frequent contact with young people to build trust underpinned the success of some of the tools, as did offering incentives for taking part and skills development using creative methods. The review also suggests that successful priority setting processes with young people involve consideration of power dynamics, since young people’s decisions are likely to be made together with family members, health professionals and academics. Discussion Young people’s engagement in decision-making about their health is best achieved through investing time in building strong relationships and ensuring young people are appropriately rewarded for their time and contribution. If young people are to be instrumental in improving their health and architects of their own futures, decision-making processes need to respect young people’s autonomy and agency. Our review suggests that methods of power-sharing with young people do exist but that they have yet to be adopted by organisations and global institutions setting global health policy

    COVID‑19 in pregnant women in South Africa: A retrospective review

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    Background. The majority of maternal deaths in South Africa (SA) occur as a result of non-pregnancy-related infections (NPRI). Pregnancy is a known risk factor in severe COVID‑19, increasing the burden of NPRI in SA. In this study, we describe the prevalence, profile and clinical outcomes of pregnant women with COVID‑19 admitted to a tertiary facility. Objectives. To describe the prevalence, profile and clinical outcomes of pregnant women with COVID‑19 admitted to a tertiary facility in Gauteng, SA. Methods. We performed a retrospective review of all pregnant women with COVID‑19 admitted to Charlotte Maxeke Johannesburg Academic Hospital between 6 March and 30 August 2020. Data collected included demographics, medical history, obstetric history, clinical findings and laboratory variables. Outcomes assessed were mortality, admission to intensive care unit (ICU), symptomatic v. asymptomatic disease, maternal and fetal outcome and mode of delivery. Results. A total of 204 pregnant women were included in the study. Of these, 33 (16.2%) women were critically ill, with 21 (10.3%) admitted to the ICU and 3 (1.5%) deaths related to COVID‑19. The median gestational age was 37 weeks and median birthweight 2 940 g. Sixty-seven women (33%) were HIV-positive, in keeping with national statistics regarding HIV in pregnancy. Caesarean section was the most common mode of delivery (n=105, 60%). However, no women underwent caesarean section for indications related to COVID‑19. Conclusion. COVID‑19-related mortality in our cohort was higher than that seen internationally, likely due to differences in background maternal mortality rates and difficulty in accessing care

    THE VLT LEGA-C spectroscopic survey:the physics of galaxies at a lookback time of 7 Gyr

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    The Large Early Galaxy Census (LEGA-C) is a Public Spectroscopic Survey of ~3200 K-band selected galaxies at redshifts z = 0.6 − 1.0 with stellar masses M∗>1010M⊙{M}_{*}\gt {10}^{10}\quad {M}_{\odot }, conducted with VIMOS on ESO's Very Large Telescope. The survey is embedded in the COSMOS field (R.A. = 10h00; decl.  =  +2  deg\mathrm{decl}.\;=\;+2\;\mathrm{deg}). The 20 hr long integrations produce high-signal-to-noise ratio continuum spectra that reveal ages, metallicities and velocity dispersions of the stellar populations. LEGA-C's unique combination of sample size and depth will enable us for the first time to map the stellar content at large lookback time, across galaxies of different types and star formation activity. Observations started in 2014 December and are planned to be completed by mid 2018, with early data releases of the spectra and value-added products. In this paper we present the science case, the observing strategy, an overview of the data reduction process and data products, and a first look at the relationship between galaxy structure and spectral properties, as it existed 7 Gyr ago
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