590 research outputs found

    An investigation of the perceptions of South African students with regards to accelerated learning courses

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    The cost of repeating a module has both financial and social implications. The social implications include increased workloads when repeating a module and students often not being able to graduate within the prescribed minimum course period. A possible solution for this is the use of accelerated learning courses, in the form of summer or winter schools. These schools provide students with another opportunity to pass a module, during the summer or winter recess, using an accelerated learning mode, and consequently complete modules with prerequisites of failed modules in the following year. Using an accelerated learning approach, a summer or winter school covers a large portion of the content in semester or year modules in a shortened timeframe outside the normal academic period. Using a questionnaire approach, the various perceptions of first year students at the end of the academic year regarding the use of these schools were obtained and analysed. The timing of the end of the academic year allows students to familiarise themselves with the various accelerated learning courses offered to them throughout the academic year. The findings suggest that students have a positive perception of these schools despite most of them not having had previous experience of completing an accelerated learning course. Although previous literature has indicated that students are hesitant to complete finance-related modules in an accelerated learning format versus traditional semester and year modules, the perceptions indicate that students are willing to engage in financial modules, with the students identifying that the benefits of these accelerated learning courses exceed the cost. The findings suggest that students who are presented with various non-academic obstacles throughout the traditional module are able to use summer or winter schools as a way to reduce exposure to these obstacles and complete an accelerated learning course. The use of these schools therefore presents an area for module developers to consider when implementing these schools as a way to improve throughput rates, thereby contributing in a positive way to students’ financial and social health

    Identification of Silver and Palladium in Irradiated TRISO Coated Particles of the AGR-1 Experiment

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    Evidence of the release of certain metallic fission products through intact tristructural isotropic (TRISO) particles has been seen for decades around the world, as well as in the recent AGR-1 experiment at the Idaho National Laboratory (INL). However, understanding the basic mechanism of transport is still lacking. This understanding is important because the TRISO coating is part of the high temperature gas-cooled reactor functional containment and critical for the safety strategy for licensing purposes. Our approach to identify fission products in irradiated AGR-1 TRISO fuel using scanning transmission electron microscopy (STEM), Electron Energy-Loss Spectroscopy (EELS) and Energy Filtered TEM (EFTEM), has led to first-of-a-kind data at the nano-scale indicating the presence of silver at triple-points and grain boundaries of the SiC layer in the TRISO particle. Cadmium was also found in the triple junctions. In this initial study, the silver was only identified in SiC grain boundaries and triple points on the edge of the SiC-IPyC interface up to a depth of approximately 0.5 ÎĽm. Palladium was identified as the main constituent of micron-sized precipitates present at the SiC grain boundaries. Additionally spherical nano-sized palladium rich precipitates were found inside the SiC grains. No silver was found in the center of the micron-sized fission product precipitates using these techniques, although silver was found on the outer edge of one of the Pd-U-Si containing precipitates which was facing the IPyC layer. Only Pd-U containing precipitates were identified in the IPyC layer and no silver was identified in the IPyC layer. The identification of silver alongside the SiC grain boundaries and the findings of Pd inside the SiC grains and alongside SiC grain boundaries provide important information needed to understand silver and palladium transport in TRISO fuel, which has been the topic of international research for the past forty years. The findings reported in this paper may support the postulations of recent research that Ag transport may be driven by grain boundary diffusion. However, more work is needed to fully understand the transport mechanisms. Additionally, the usefulness of the advanced electron microscopic techniques for TRISO coated particle research is demonstrated in this paper

    Concussion knowledge and attitudes among amateur South African rugby players

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    Background: The South African Rugby Union’s BokSmart programme currently educates coaches and referees on concussion. Rugby players are often more familiar with their teammates than the coach or referee. Therefore they are well-positioned to play a pivotal role in rugby safety if they have adequate knowledge to identify subtle signs and abnormal behaviour displayed by a concussed teammate. However, no programme focuses on concussion education among South African rugby players and there is a dearth of literature on concussion education programmes among rugby players which could lead to safer return to play (RTP) habits.Objectives: To evaluate South African rugby players’ concussion knowledge and attitudes/behaviours regarding RTP following a concussion.Methods: A descriptive, cross-sectional study was used. Participants (n=294) were divided into junior amateur high school (JAHS) (n=216) and senior amateur club (SAC) (n=78) players. The modified RoCKAS-ST questionnaire was used to evaluate their concussion knowledge index (CKI) and concussion attitudes/behaviours index (CAI) regarding RTP.Results: On average, 62% (JAHS) and 60% (SAC) of the CKI questions were answered correctly. JAHS participants correctly identified 66% of concussion symptoms, similarly to the SAC participants (63%), rendering similar (p=0.37) overall CKI scores when comparing the two groups. The CAI questions yielded similar (p=0.98) results between the groups, reporting safe responses in 66% (JAHS) and 67% (SAC) of the items.Discussion and conclusion: Junior and senior South African amateur rugby players lacked approximately one-third of essential concussion knowledge, which may lead to a display of unsafe attitudes/behaviours to concussion and RTP. Further research is warranted to inform educational programmes on concussion among rugby players.Keywords: post-concussion syndrome, rugby union, return to play, safety, South Afric

    Radiation Shielding Analysis and Optimisation for the MinPET Kimberlite Sorting Facility using the Monte Carlo Calculation Code, MCNPX

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    Abstract: Radiation shielding calculations, analysis and optimization process carried out in order to design shielding for a Mineral-Positron Emission Tomography (MinPET) facility are presented. PET is a nuclear imaging technique commonly used in diagnostic medicine. The technique is based on the detection of 511 keV coincident and co-linear photons produced from the annihilation of a positron (produced by a positron emitter) and a nearby electron. This technique is currently being developed for mineral detection and quantification, particularly diamonds in kimberlite rocks through the MinPET facility. The facility is aimed at improving diamond mining through the early detection of the diamond bearing rocks. High energy photons are produced via bremsstrahlung when a high energy, 40 MeV 5mA, electron beam impinges on a high density target - tungsten..

    Crystallization of recombinant Bacteroides fragilis glutamine synthetase (GlnN) isolated using a novel and rapid purification protocol

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    Glutamine synthetase enzymes (GSs) are large oligomeric enzymes that play a critical role in nitrogen metabolism in all forms of life. To date, no crystal structures exist for the family of large (1 MDa) type III GS enzymes, which only share 9% sequence identity with the well characterized GSI and GSII enzymes. Here we present a novel protocol for the isolation of untagged Bacteroides fragilis GlnN expressed in an auxotrophic Escherichia coli strain. The rapid and scalable two-step protocol utilized differential precipitation by divalent cations followed by affinity chromatography to produce suitable quantities of homogenous material for structural characterization. Subsequent optimizations to the sample stability and solubility led to the discovery of conditions for the production of the first diffraction quality crystals of a type III GS enzyme

    Sample Preparation Techniques for Grain Boundary Characterization of Annealed TRISO-Coated Particles

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    Crystallographic information about layers of silicon carbide (SiC) deposited by chemical vapor deposition is essential to understanding layer performance, especially when the the layers are in nonplanar geometries (e.g., spherical). Electron backscatter diffraction (EBSD) was used to analyze spherical SiC layers using a different sampling approach that applied focused ion beam (FIB) milling to avoid the negative impacts of traditional sample polishing and address the need for very small samples of irradiated materials for analysis. The mechanical and chemical grinding and polishing of sample surfaces can introduce lattice strain and result in the unequal removal of SiC and the surrounding layers of different materials due to the hardness differences among these materials. The nature of layer interfaces is thought to play a key role in the performance of SiC; therefore, the analysis of representative samples at these interfacial areas is crucial. In the work reported herein, a FIB was employed in a novel manner to prepare a more representative sample for EBSD analysis from tristructural-isotropic layers that are free of effects introduced by mechanical and chemical preparation methods. In addition, the difficulty of handling neutron-irradiated microscopic samples (such as those analyzed in this work) has been simplified using pretilted mounting stages. The results showed that while the average grain sizes of samples may be similar, the grain boundary characteristics can differ significantly. Furthermore, low-angle grain boundaries comprised 25% of all boundaries in the FIB-prepared sample compared to only 1% to 2% in the polished sample from the same particle. This study demonstrated that the characterization results from FIB-prepared samples provide more repeatable results due to the elimination of the effects of sample preparation

    The relationship between obesity, leptin, adiponectin and the components of metabolic syndrome in urban African women, Free State, South Africa

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    Objectives: Obesity prevalence is increasing worldwide. In South Africa, older and urbanised African women have significantly higher rates of obesity. Limited information is available on the relationship between anthropometric parameters, adipokines and metabolic health status of African women. This study investigated the relationship between obesity, adipokines and the components of metabolic syndrome in urban African women.Methods: This study included 135 urban African women that were 26–63 years of age, identified with metabolic syndrome in the urban leg of the Assuring Health for All in the Free State (AHA-FS) study. To establish anthropometric status, the following measures were taken: body weight, height and waist circumference. Blood was drawn to determine leptin, adiponectin levels and metabolic status.Results: Adiponectin levels in obese women were significantly decreased compared to normal weight women. Leptin levels and leptin:adiponectin ratios (L:A) were increased in the obese group compared to the overweight and normal weight groups. Leptin and L:A showed strong positive correlations with body mass index and waist circumference. Adiponectin levels decreased as the number of components of metabolic syndrome increased. The L:A ratio was significantly lower in women with elevated triglycerides and significantly higher in women with elevated blood glucose levels. Adiponectin levels were significantly lower in women with elevated blood glucose.Conclusion: This study confirms the inverse relationship between adiponectin and leptin with increased body adiposity. Results indicate that waist circumference, fasting blood glucose and triglyceride levels are the metabolic syndrome components most closely associated with altered adiponectin and leptin levels and L:A in urban African women with metabolic syndrome.Keywords: adipokines, adiponectin, components of metabolic syndrome, leptin, L:A ratio, obesit

    Performance indicators that discriminate winning and losing in elite men’s and women’s Rugby Union

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    This study aimed to identify performance indicators that discriminate winning and losing in elite men’s and women’s Rugby Union during the latest World Cup competitions. The knockout stages of the men’s 2015 Rugby World Cup (n = 8) and women’s 2014 Rugby World Cup (n = 8) were compared. Findings suggest that in the men’s game, winning teams kicked a greater percentage of possession in the opposition 22–50 m with a view to gaining territory and pressuring the opposition (winners = 16%, losers = 7%). In the women’s game successful teams adopted a more possession-driven attacking approach in this area of the pitch. Successful women’s teams appear more willing to attack with ball in hand following a kick receipt and adopt a more expansive game through attacking with wider carries in the outside channels. The percentage of lineouts won on the opposition ball was found to be an important performance indicator that discriminates winners and losers, regardless of sex (winners = 18%, losers = 11%). Findings suggest successful men’s and women’s teams adopt different tactical approaches to knockout competitions, this knowledge should be used as a basis for coaches to develop tactical approaches and training methods which are sex dependent

    Supporting Treatment for Anti-Retroviral Therapy (START) together: protocol for a pilot, randomized, couple-based intervention to promote women's ART adherence and men's engagement in HIV care in KwaZulu-Natal, South Africa

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    Background: South Africa currently has the greatest number of people with HIV globally. The country has not yet met its 95-95-95 goals, with different gaps in the HIV care cascade for women and men. This paper reports on a protocol to pilot test a couple-based intervention designed to improve women's antiretroviral therapy (ART) adherence and men's engagement in care in heterosexual couples living in the Vulindlela area of KwaZulu-Natal, South Africa. Study goals are two-fold: (1) assess the acceptability, feasibility, and fidelity of the experimental intervention, START Together, and (2) collect efficacy data on START Together for women's ART adherence, men's engagement in HIV care, and the couple's relationship functioning. Methods: Women (N = 20) who were not engaged with ART adherence (defined via self-reported ART difficulties, record of missed clinic visits, or viral non-suppression) are the target patients; male partners are not required to know or disclose their HIV status to be part of the study. Couples are randomized 1:1 to the experimental treatment (START Together) or treatment as usual (referrals to the local clinic to support ART adherence or any other HIV-related care). START Together is a 5-session intervention based in cognitive-behavioral couple therapy, which is a skill-based intervention focusing on communication and problem-solving skills, and Life Steps, a problem-solving intervention identifying barriers and solutions to medication adherence. Couples are assessed at baseline, post-treatment (8 weeks post-randomization), and follow-up (12 weeks post-randomization). Conclusion: This study will provide preliminary implementation and efficacy data on whether this novel approach has potential to improve women and men's HIV and healthcare-related needs

    Language capabilities of Free State doctors

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