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- ItemBinding of deoxy-thymidine-5'-triphosphate and deoxyadenosine-5'-triphosphate to chrysotile asbestos(Academy of Science for South Africa, 2003) Hawtrey, A.; Pieterse, A.; Van Zyl, J. M.; Bester, A. J.; Harington, J. S.Tritiated deoxythymidine-5'-triphosphate ([3H]dTTP) and deoxyadenosine- 5'-triphosphate ([3H]dATP) were found to bind strongly to fibres of chrysotile asbestos. Binding of both triphosphates to amosite and crocidolite, however, was much less than that to chrysotile. Further work with chrysotile showed that the binding appears to be electrostatic in nature, with the negative phosphate groups of the nucleotides attaching to the positively charged groups on the mineral fibre. Attachment of the triphosphates to the mineral surface was found to be concentration dependent. Time curves of binding indicated that, for both nucleoside triphosphates, binding was rapid at 20oC and 37oC. Strong binding was also observed at 55oC. Binding at the higher temperatures depended on the type of buffer used and pH. Bound [3H]dTTP and [3H]dATP could be partially removed from chrysotile by 0.1 M sodium pyrophosphate after a short incubation at 20oC. Various chemical reagents that affected binding were studied and are discussed. The possible use of chrysotile asbestos as a solid phase material for the polymerization of dTTP and dATP or activated 5'-phosphorimidazolide of adenosine is also discussed.
- ItemCompassionate citizenship and higher education re-imagining : perspectives on higher education(Higher Education South Africa, 2003) Waghid, Y.Higher education re-imagining in South Africa primarily focuses on educating students to be responsible citizens. The National Plan for Higher Education (2001) aims in the first instance at cultivating in students the capacity to deliberate respectfully with one another in order to become responsible citizens. This article argues that deliberation and respect are necessary but not sufficient conditions to foster a sense of responsible citizenship. Students also need to be taught to develop the quality that Nussbaum (2001) refers to as "compassionate citizenship".
- ItemComputer simulation of internal combustion engine flow processes(South African Institution of Mechanical Engineers, 2002) Van Vuuren, C. M.; Thiart, G. D.; Taylor, A. B.A computer code for the simulation of internal combustion engine processes is presented. The main objective of the code is to serve as a tool for the design of inlet and outlet manifolds of combustion engines. The code is built around a two-zone thermodynamic combustion model that is linked to a quasi one-dimensional unsteady method of characteristics pipe flow model and a camshaft model. Two simple test cases are presented to show that the pipe flow model functions correctly. Predictions of the crankshaft power delivered by a commercial internal combustion engine computed by means of the code are shown to compare favourably with measured results. An example illustrating the usefulness of the code as a design tool is also presented.
- ItemMeasurement of the magnitude of force applied by students when learning a mobilisation technique(2003) Smit, E.; Conradie, C.; Wessels, J.; Otto, R.; Witbooi, I.Passive accessory intervertebral movements (PAIVM’s) are frequently used by physiotherapists in the assessment and management of patients. Studies investigating the reliability of passive mobilisation techniques have shown conflicting results. Therefore, standardisation of PAIVM’s is essential for research and teaching purposes, which could result in better clinical management. In order to standardise graded passive mobilisation techniques, a reliable, easy-to-use, objective measurement tool must be used. The aim of this study was to determine whether it is necessary to quantify the magnitude of force applied when teaching a grade I central posteroanterior (PA) mobilisation technique (according to Maitland) on the cervical spine. An objective measurement tool (FlexiForceTM) was used to determine the consistency of force applied by third and fourth year physiotherapy students while performing this technique. Twenty third- and 20 fourth year physiotherapy students (n=40) were randomly selected. Each subject performed a grade I central PA on sensors placed on C6 for 25 seconds. The average maximum grade 1 force applied by the third year students was significantly higher than the force applied by the fourth year students (p=0.034). There was a significantly larger variation in applied force among third years (p=0.00043). The results indicate that the current teaching method is insufficient to ensure inter-therapist reliability amongst students, emphasising the need for an objective measurement tool to be used for teaching students. The measurement tool used in this study is economical, easily applied and is an efficient method of measuring the magnitude of force. Further research is needed to demonstrate the reliability and validity of the tool to assist teaching and research in a clinical setting.
- ItemPhysiotherapy students' perceptions of an innovative approach to clinical practice orientation(AOSIS, 2002) Faure, M. R.; Unger, M.; Burger, M.The transition from the classroom to clinical practice is stressful for many students. In the current situation in South Africa with the shortages of clinicians’ posts in hospitals, this transition is even more difficult given the reduced time that clinicians have for supervising undergraduate students. The University of Stellenbosch initiated structured peer-led introduction to clinical education (SPLICE), during which senior physiotherapy students orientate second year students to clinical practice. The aim of this study was to investigate the perceptions of all of the second, third and fourth year students who took part in these SPLICE sessions. This information was captured using a questionnaire with open and closed questions. The response of all of the students was extremely positive. Common to all cohorts of students was the opinion of the motivational benefits of the sessions as well as the opinion that their confidence increased. Students in the various years of study differed in the ways in which they felt more confident. Closely linked were those comments referring to a sense of increased preparedness for clinical practice and a positive learning environment. A positive change in attitude towards clinical practice was also noted in many second year students. Further research is needed into the effect that SPLICE might have had on the second year students when they enter clinical practice as third year students. The role and opinions of patients during these sessions, and indeed during any clinical education sessions, including clinical examinations, needs further investigation.
- ItemQuantifying the role of personal management style in the success of investment portfolios(Operations Research Society of South Africa, 2002) Wagenaar, E. A.; Van Vuuren, J. H.It is extremely difficult to quantify the effect of different management styles of portfolio managers upon the success of their portfolios. Various mathematical models in the literature attempt to predict the risk and returns of portfolios according to changes in the economic arena, but these models usually do not take into account the personal styles of portfolio managers. The aim of this paper is a modest attempt at quantifying the effect of different managerial styles upon decisions regarding portfolios. This is accomplished by the formulation of a mathematical performance index that portrays the influence of a portfolio manager's personal and managerial characteristics on the success of his portfolio.
- ItemTreatment utilisation and trauma characteristics of child and adolescent inpatients with posttraumatic stress disorder(AOSIS, 2003) Traut, A.; Kaminer, D.; Boshoff, D.; Seedat, S.; Hawkridge, S. M.; Stein, D. J.Objective. Few empirical studies have addressed the impact of trauma exposure and posttraumatic stress disorder (PTSD) on treatment utilisation and outcome in South African youth. This study was undertaken to document demographic, clinical, and treatment characteristics of child and adolescent inpatients with PTSD.