Tutors' views on the integrated tutor model in open distance learning

The facilitation of learning by tutors is a worldwide phenomenon that is supported by most open and distance learning (ODL) institutions. It is a strategy employed to achieve academic success. This qualitative intrinsic case study explored the views of tutors at the University of South Africa (Unisa) about the implementation of the Integrated Tutor Model (ITM) which supports student learning. The successes, challenges and impact of the ITM on the tutors’ delivery of tutorials are not fully known. Therefore, the findings of this study will highlight the successes, challenges and impact of the ITM which Unisa can use to improve the model. Data were gathered through face-to-face interviews with six tutors who were purposively selected from Unisa’s Gauteng region. The findings revealed successes and challenges of the ITM that affect the support that is due to the students via tutorage. These findings explain the application of the ITM that can assist Unisa in strengthening or reviewing both the tutor system and the model

Traditional eye medication and pterygium occurrence in Limpopo Province

Background. The relative importance of environmental and hereditary factors in the occurrence of pterygium in African blacks has not been reported.Aim. To investigate the relative significance of factors associatedwith pterygium occurrence.Methods. This was a prospective case-controlled study where150 pterygium patients and 150 controls participated. Interviewswere conducted, eyes examined and multivariate analysis done. Thefamilies of 51 pterygium cases and 50 controls were examined forpresence of pterygium.Results. Of 150 cases and 150 controls, 79 (52.6%) and 60 (40%)used traditional eye drops (odds ratio (OR) 2.03; p=0.009. Ten cases (6.6%) and 26 controls (17.3%) had unstable tear film (OR 0.30; p=0.007. Forty-six cases (30.6%) and 15 controls (10%) reported a positive family history (OR 3.93; p<0.001). Groups of 3 - 5 pterygium cases in a household occurred in 36 of 51 pterygium families (70.5%) v. 1 of 50 controls (2%).Conclusions. Pterygium occurrence was associated with the use of traditional eye drops, a positive family history and having groupsof diagnosed pterygium-affected relatives. However, unstable tearfilm seemed protective against pterygium occurrence

Effect of pH on the recovery and grade of base metal sulphides (PGMs) by flotation

This study investigated the effect of pH on the recovery and grade of the Platinum Group Metals (PGMs) and base metal sulphides from the UG2 ore of the Bushveld Complex. This was achieved through running a series of test work in a Denver flotation cell at varying pH 6-11 at constant reagent dosage. The UG-2 reef is characterized by two predominant gangue phases i.e. chromite and silicate, that have significantly different physical and chemical properties. The test work was aimed at evaluating which pH gives best recoveries, and finding the effect of the chrome content in these recoveries. A pH of 9 gave the highest recovery compared to other pH ranges. However, the highest PGM grade was attained at a pH of 6 which is slightly acidic. Ideally this trend could be expected since the collectors (xanthates) are more stable in alkaline medium. The higher PGM recovery was also accompanied by higher chrome content as a result of their similar chemical properties

The Functional Importance of Forbs in Grassland Ecosystems

Herbaceous vegetation in grassland ecosystems is characterised by grass dominance in a species-rich forb-grass mixture. Forbs (i.e. the non-graminoid herbaceous component) represent the largest proportion of total species- and functional richness, which secure important ecosystem functions. Although grasses remain the most important forage source, certain forb species provide nutritious food sources for herbivores. Moreover, forbs provide food- and habitat sources to enhance invertebrate diversity and hence, agricultural food security through the maintenance of healthy pollinator communities. Important food and medicinal sources for human livelihoods in developing countries are also largely contributed by forbs. However, the dynamics and ecology of forb species are poorly understood in rangeland systems. Increasing global pressures are threatening the hyper-diverse grassland ecosystems (including African savannas) and in particular the diversity of the forb flora. The sub-ordinate role of forbs in savanna and grassland rangeland management practices led us to accumulate evidence of important ecosystem functions and services provided by this diverse life form. In this study, we present results that were obtained from several independent studies in which forb data were collected and analysed as an equally important herbaceous life form, to contribute to our current understanding of the ecology of grassland ecosystems. Our results revealed evidence of forbs as important forage for large African mammalian herbivores, including domestic cattle, during periods when other forage resources are severely limited. However, sustained overgrazing can severely deplete forb populations and diversity. Forbs as grazing indicators have been identified as the basis of a proposed forb-condition scoring method for mesic grasslands. Furthermore, the importance of intermediate disturbances, such as moderate grazing and/or the maintenance of crop field margins were identified for invertebrate community conservation. Studies on useful indigenous plants exposed forbs as an important life form to provide food- and medicinal resources to human livelihoods in African grassland ecosystems

Phase equilibrium of volatile organic compounds in silicon oil using the UNIFAC procedure : an estimation

This paper focuses on the phase equilibrium of volatile organic compounds in silicon oil chemically known as PDMS (polydimethylsiloxane) at infinite dilution. Measurements can be expensive and time consuming, hence the need for thermodynamic models which allow the calculation of the phase equilibrium behavior using a limited number of experimental data. The objective of this study was to predict infinite dilution activity coefficients of selected VOCs (volatile organic compounds) in PDMS using the Original UNIFAC model. The predicted results show that PDMS can be used to abate volatile organic compounds from contaminated air streams. The results obtained in this work are comparable to those obtained by the same authors through measurements such as the static headspace and the dynamic gas liquid chromatographic techniques as well as other literature. Although the UNIFAC group contribution method over estimate the infinite dilution activity coefficients, the results of this work may be applied in preliminary phases of process design, simulation and feasibility studies

Parametric effects on leaching behavior of nickel-copper matte in ammonia

Abstract: Please refer to full text for abstrac

Nurturing lifelong learning in communities through the National University of Lesotho: prospects and challenges

This paper analyses one aspect of a pan-African action research project called ITMUA (Implementing the Third Mission of Universities in Africa). This particular paper draws on the data from that project to explore the National University of Lesotho’s contribution to lifelong learning in its communities. It provides background information on the ITMUA initiative and analyses interview and focus group responses to two case studies in terms of their contribution to lifelong learning. It uses, as its analytical framework, a modified version of Mbigi’s African perspective on the four De Lors’ ‘pillars’, by adding a fifth pillar, courtesy of Torres. The paper argues that community engagement is a two-way process between universities and their wider constituencies with opportunities for mutual lifelong learning. But there are also challenges of understanding and process which must be addressed if the full range of these lifelong learning pillars is to be accommodated within African contexts. The paper provides an introduction to the history of community engagement in Africa as a university mission, followed by a brief discussion of lifelong learning within African perspectives. After describing the particular context of Lesotho, the concept of community service and community engagement in contemporary African contexts introduces the action research project and the case studies. The final part of the paper presents and discusses the research findings

Latex allergy and its clinical features among healthcare workers at Mankweng Hospital, Limpopo Province, South Africa

BACKGROUND AND OBJECTIVES. Latex allergy, caused by sensitisation in atopic individuals, is a common occupational disease among healthcare workers who use latex gloves. It may be present in non-atopic individuals as well. The main objective of this study was to document the prevalence and disease spectrum of latex allergy at Mankweng Hospital, Limpopo Province, South Africa. The secondary objective was to determine clinical presentation of the disease. METHODS. A cross-sectional descriptive study, with an analytical component, was conducted among healthcare workers who worked in high-risk areas for latex sensitisation. ImmunoCAP testing was performed and followed by a skin-prick test (SPT) in those who tested negative to the blood test. RESULTS. Two hundred screening questionnaires were distributed to healthcare workers at the hospital. Of these 158 (79.0%) were returned, with 59 participants meeting the inclusion criteria (experiencing symptoms due to wearing latex gloves). The mean age of the participants was 39.6 years (standard deviation 9.8 years, range 20 - 60 years). There were more females (98.1%) than males (1.9%). Glove-related symptoms were present in 59 subjects (37.1%), in 7 (11.9%) of whom the ImmunoCAP was positive to latex (95% confidence interval 4.2 - 22.9%). Fourteen participants were lost to follow-up before the SPT was performed. Thirty-eight of the participants with negative ImmunoCAP tests underwent SPT. Positive SPTs were reported in 5 of these 38 workers (13.2%), indicating that the ImmunoCAP test missed 11.1% (5/45) of latex-allergic individuals. The prevalence of latex allergy in this study was 8.3% (12/144). A denominator of 144 was used, as there is a possibility that some of the 14 individuals lost to follow-up could have tested positive to latex sensitisation by SPT. The symptoms experienced by latex-sensitised workers were rhinitis (100.0%), asthma (50.0%), dermatitis (25.0%), severe anaphylaxis (8.3%), abdominal pain (8.3%) and angio-oedema (8.3%). CONCLUSION. Our findings reveal that latex allergy is a problem at our hospital. The prevalence of 8.3% is comparable to findings in other South African centres. We recommend a latex-free protocol for high-risk areas and healthcare workers.http://www.samj.org.zaam2014ay201

From waste cooking oil to oxygen-rich onion-like nanocarbons for the removal of hexavalent chromium from aqueous solutions

Vegetable cooking oil is used in domestic and commercial kitchens owing to its ability to modify and enhance the taste of the food through the frying process. However, as the oil is used through several frying cycles, it changes colour to dark brown and acquires an unpleasant smell. At this point, the waste oil is usually discarded, thereby finding its way into freshwater streams due to poor disposal and thus becoming an environmental pollutant. To provide an alternative, ‘green’ route to waste oil disposal, herein we report on the metal-free synthesis of onion-like nanocarbons (OLNCs) made from waste cooking oil via flame pyrolysis. The OLNCs were then applied in the removal of hexavalent chromium ions from aqueous solutions. The as-synthesised OLNCs were found to have similar properties (size, quasi-spherical shape etc.) to those synthesised from pure cooking oils. The Fourier-transform infrared spectroscopy data showed that the OLNCs contained C-O-type moieties which were attributed to the oxygenation process that took place during the cooking process. The OLNCs from waste oil were applied as an adsorbent for Cr(VI) and showed optimal removal conditions at pH = 2, t = 360 min, Co = 10 mg/L and Q0max = 47.62 mg/g, superior to data obtained from OLNCs prepared from pristine cooking oil. The results showed that the OLNCs derived from the waste cooking oil were effective in the removal of hexavalent chromium. Overall, this study shows how to repurpose an environmental pollutant (waste cooking oil) as an effective adsorbent for pollutant (Cr(VI)) removal. Significance: • Waste cooking oil outperformed olive oil as a starting material for the production of OLNCs for the removal of toxic Cr(VI) from water. • The superior performance of the OLNCs from waste cooking oil was attributed to the higher oxygen content found on their surface and acquired through the cooking process. • Not only are the OLNCs produced from waste cooking oil effective in the removal of Cr(VI), but they can be used multiple times before replacement, which makes them sustainable