An investigation into the pre-service training of secondary school mathematics teachers at colleges of education administered by the House of Representatives
- Authors: Hendricks, Mogamat Armien
- Date: 1989
- Subjects: Mathematics teachers -- Training of -- South Africa Mathematics -- Study and teaching (Higher) -- South Africa Colored people (South Africa) -- Education Colored people (South Africa) -- Education (Secondary)
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1864 , http://hdl.handle.net/10962/d1004591
- Description: This study involves an investigatioh into the nature and effectiveness of the pre-service training, where provided, of secondary school Mathematics teachers at the 11 colleges of education administered by the House of Representatives in the Republic of South Africa. The purpose of this study is to determine whether the HDE (Secondary) course offered at some of the aforementioned colleges of education is justified, In spite of the fact that it contravenes the requirements of the Education Act, No. 73 of 1969. Three different questionnaires were designed and during 1986 were sent to heads of Mathematics departments at the aforementioned colleges of education , to Mathematics teacher educators at these colleges and to beginning secondary school Mathematics teachers, teaching at schools administered by the House of Representatives in the Eastern Cape and Natal. The findings of this study show that the secondary course for Mathematics teachers is only offered at 5 of the 11 colleges of education and only a small percentage of students take this course. During 1986 most of the Mathematics teacher educators at the colleges of education were not suitably qualified. The study also shows that the Mathematics curriculum for the training of secondary school teachers is inadequate and a revision thereof is thus recommended. An obvious conclusion drawn from the findings is that the training of secondary school Mathematics teachers at these colleges of education is still in an early stage of development. One of the main recommendations of this study is that the training of secondary school Mathematics teachers at colleges of education administered by the House of Representatives should be terminated , in view of its ineffectiveness and In accordance with Education Act , No . 73 of 1969. On the other hand, in case this is not possible, suggestions are also made for the improvement of the pre-service training of secondary school mathematics teachers at these colleges of education.
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An investigation into the properties of cotton fibres as used in nonwoven fabrics
- Authors: Lutseke, Nothando Sazikazi
- Date: 1989
- Subjects: Cotton -- Analysis , Fibers -- Analysis , Nonwoven fabrics -- Analysis , Textile chemistry
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4552 , http://hdl.handle.net/10962/d1018241
- Description: The purpose of this investigation was to determine the properties that characterise cotton fibres in the various stages in the CPNF process as well as to determine which fibre characteristics a r e required to entangle the fibres to produce a successful CPNF . The criteria adopted in this work for a successful CPNF include: 1. the tensile strength of the fabrics 2. a well-defined pattern 3. absorbency and wicking The properties selected for investigation were 1. the cotton fibre surface (using SEM and DSC analyses) 2. the degree of degradation of the cotton fibre as a result of the CPNF process (using cellulose fluidity measurements) 3. the non-cellulosic content of the fibre (using IR, DSC, and Chemical analyses) 4. fibre friction 5. absorbency and wicking 6. tensile properties Analysis of the results indicates clearly what the fundamental properties of the cotton fibre must be for a successful cotton CPNF to be manufactured. The conclusions also indicate the necessary properties a man-made fibre must have to produce a successful CPNF.
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An investigation into the social/personality guidance needs of a group of secondary school pupils
- Authors: McGregor, Dale
- Date: 1989
- Subjects: Interpersonal relations in adolescence , Personality in adolescence , Educational counseling , Adolescent psychology , Youth -- Counseling of
- Language: English
- Type: text , Thesis , Masters , MEd
- Identifier: vital:1353 , http://hdl.handle.net/10962/d1001419
- Description: School guidance aims to meet the social/personality, educational and vocational needs of pupils, and the curriculum, organised and drawn up by the relevant State education departments, attempts to address these needs. This investigation set out to discover the guidance needs of pupils specifically in the social/personality area, and further, to state these needs in such a way as to allow the logical development of guidance programmes. Group and individual interviews were conducted using a sample of 72 high school pupils, selected from standards six to eight. The results show clearly the areas in which the pupils perceive their needs to lie. It is also apparent that further research in this area is strongly indicated.
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Apneic Bradycardia : terrestrial and aquatic responses in man under working conditions
- Authors: Manley, Elizabeth
- Date: 1989
- Subjects: Apnea Respiration -- Measurement Heart rate monitoring Work -- Physiological aspects Underwater -- Physiology
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5098 , http://hdl.handle.net/10962/d1001838
- Description: The focus of this research was the reappraisal in physiological and psychophysical terms of current equivocal theories regarding the onset, course and termination of apneic bradycardia. Sixteen healthy male subjects participated in four separate testing sessions . Maximal oxygen consumption (VO₂ max) was measured on land and underwater using an identical direct, continuous progressive cycle ergometer test. On each of two other occasions subjects exercised in either environment at 50, 70 and 90% of the appropriate VO₂ max, during which time heart rate was continuously recorded. An initial apneic bout at each exercise intensity was followed by performance of the same workload without apnea for an equivalent period of time. Ratings of perceived exertion (RPE) were also monitored. While apneic bradycardia occurred at each exercise intensity studied underwater, it was apparent only at 50% VO₂ max on land. With the exception of between 50 and 90% VO₂ max on land, the mean apneic heart rates did not differ with varying exercise intensity (p<0.05); nor did the lowest heart rate recorded, although this was lower underwater than on land. Apart from 70% VO₂ max on land, apneic heart rates were lower than the equivalent values measured during exercise without apnea. Land and underwater heart rates during apneic and non-apneic conditions did not differ until 90% VO₂ max. The effects of increasing exercise intensity upon the onset of bradycardia were evident in that it occurred earlier at 50% VO₂ max underwater than at the heavier workloads, and only at 50% VO₂ max on land. The mean breath-hold duration did not differ between the land and underwater environments, nor was it affected by increasing exercise intensity. The order in which breath-holds was performed did not alter the length of apnea. Land and underwater RPE did not differ and increased with increasing exercise intensity in both environments. During apneic exercise RPE was greater than the equivalent exercise without apnea. Twelve of the original 16 subjects were divided equally into two groups on the basis of vital capacity expressed relative to body surface area. Vital capacity was measured during the first laboratory session. Neither the mean heart rate response to apneic exercise at 50% V0₂ max in both environments, nor the lowest heart rates recorded differed between groups, prompting the conclusion that lung volume did not affect apneic bradycardia. Despite a longer breath-hold duration for Group A (large relative lung volume) than Group B (small relative lung volume), the onset point of bradycardia was the same for either group when expressed relative to total breath-hold duration
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Arguments for other minds
- Authors: Dowling, Dolina Sylvia
- Date: 1989
- Subjects: Mind and body -- Philosophy
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: vital:2702 , http://hdl.handle.net/10962/d1001977
- Description: If I am aware of my own mental states by introspection (a) How can I know that other people have minds? and (b) How can I know what their mental states are? These are two of the questions with which I will be concerned in this dissertation. I discuss five different attempts to deal with them. (i) The claim that we can know that other people have minds by an argument from analogy. I show a number of serious flaws in Russell's and other versions of this argument. (ii) Malcolm's thesis that the criteria by which we apply mental terms to others are just different from the criteria one applies in one's own case. I argue that Halcolm's accounts of both first- and third-person criteria are not adequate. (iii) I consider Strawson claim that 'persons' is a primitive concept and that behavioural criteria are "logically adequate" for determining the correctness of statements about the mental states of others. I argue that both of his key concepts are underanalysed. (iv) A quite different attempt to answer our questions (a) and (b) is given by the empirical realist who argues that knowledge claims about other minds are best understood as hypotheses in a wider psycho-physical theory. I show that the major fault in Putnam's version of empirical realism is that he overlooks the subjective character of (iii) our mental states. (v) Finally I consider the claim, due to Nagel, that a conception of mental states is possible which incorporates both subjective and objective aspects of the phenonemon. I speculate that with a great deal of development this approach might hold the answer to our questions.
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Assessment of factors influencing the quality of surface and ground water in the Hout Bay river catchment
- Authors: Pearce, Meryl Winsome
- Date: 1989
- Subjects: Water -- South Africa -- Hout Bay Hydrology Water -- Pollution -- South Africa -- Hout Bay Water quality -- South Africa -- Hout Bay Aquatic ecology Water quality Hout Bay river (South Africa) Groundwater -- South Africa -- Hout Bay
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4800 , http://hdl.handle.net/10962/d1001900
- Description: An investigation into the quality of surface water and ground water was conducted during 1988 in the 38,8 km² Hout Bay River catchment near Cape Town. The main objective of the study was to determine those areas and activities which constitute a pollution source and to ascertain the relative proportion which each contributes to the pollution problem and health risk of the surf zone of the beach at Hout Ba . The objective was achieved by monitoring the chemical and microbiological attributes of the Hout Bay River, its tributaries and stormdrains in wet and dry conditions on a routine basis and during storm events. Hout Bay is a rapidly developing residential area in which sewage disposal occurs by means of septic tank soakaway systems. Ground water quality was monitored to investigate the contribution to contamination by septic tank effluent. Results showed that stormdrain effluent in dry and wet conditions and surface runoff during rainfall were the main vectors of pollution. Although the pollution concentration was high during dry conditions the greatest pollution discharge to the surf zone of Hout Bay occurred during storm events. In view of the proposed residential development it is imperative that pollution control measures be undertaken so as to secure the future recreational and aesthetic value of Hout Bay
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Attitudes to family planning in the Taung area of Bophuthatswana: a social work perspective
- Authors: Thekisho, Geraldine Nomonde
- Date: 1989
- Subjects: Birth control -- South Africa -- Bophuthatswana , Bophuthatswana (South Africa) -- Social conditions
- Language: English
- Type: Thesis , Masters , MSocSc
- Identifier: vital:3277 , http://hdl.handle.net/10962/d1004914 , Birth control -- South Africa -- Bophuthatswana , Bophuthatswana (South Africa) -- Social conditions
- Description: Emphasis in the study is on the prevalence of poverty especially in the so called third world developing countries. Poverty as a social problem is caused by a number of factors, viz: Over population, unemployment, illiteracy, etc. In the case of the study the focus is the rapid population growth or "population explosion" as it is commonly known. Family planning is sen as important, but not the only strategy in combatting the interrelated problem of population growth and development. The relevance and importance of social workers, as members of a multidisciplinary team in the delivery of family planning programmes is emphasised. There is evidence in the study to support the observation that Black African people in particular are reluctant to use family planning methods. Based on this evidence, the basic assumption arrived at is that there is a general unfavourable attitude to family planning in the Taung area. The research design used is exploratory-descriptive. Of the 75 areas in the district, 10 areas were included In the investigation. A stratified random sample was used, with a sample size of 200 respondents. The interview schedule was used to collect data. It was structured and consisted primarily of close-ended questions, and was analysed using the Biomedical Data Programme (B.M.D.P.). The problem is formulated from literature concerned with population growth in the Republic of South Africa as well as Bophuthatswana. The following sub-problems were described: illegitimacy; health and economic problems associated with large families; abortion; malnutrition and malnourishment; and the absence of services of the National Family Planning Programme In the Taung area. Compatibility between social work and family planning is a central concern, with community development as a significant method of intervention. The three important concepts in the study were broadly defined, viz: Overpopulation, family planning and attitude. It was established that: -the use of family planning follows rather than precedes the process of modernisation and rising economic standards; -no family planning programme can be practised universally - because of factors such as culture, need and habit. Attitudinal change is considered based on the basic assumption arrived at. Little has been done on the subject of family planning in south Africa. With regard to the role of social work in family planning, there have been impediments along the following lines: lack of firm tradition; emphasis on treatment rather than on preventive work; a view of family planning asa health measure and to be offered solely in the medical and health services. To be active in this field social workers need formal education and training. Taung: - the area of study is predominantly rural with almost all characteristics of rural areas, those of: Irregular transport services to and from remote areas; corrugated roads; primitive sanitary conditions; poor communication system; absence of electricity in villages; illiteracy and unemployment. On the other hand, development is evident especially in the health, education and welfare fields. The central findings in the study are those arising from resistances to family planning usage - politically; culturally; morally and psychologically. The general conclusions are: The high rate of unemployment is present in the sample and there is financial dependence on partners (men); the importance of social workers in family planning is emphasised; there is a desire to have large numbers of children (children feature prominently in the area and are regarded as an asset in various ways); and lastly, improved education does lead to an increase in motivation to adopt family planning practices. Against the highlighted findings, recommendations were made, viz that: Community development be used as a strategy for change; social workers be involved as team members in family planning - in policy formulation and planning of population programmes at various levels, using different methods of intervention; paramedical aides beused - because of inter alia shortage of qualified manpower and lastly formal education and training to be granted to prospective change agents in family planning delivery programmes. , KMBT_363 , Adobe Acrobat 9.54 Paper Capture Plug-in
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Comparison of different notions of compactness in the fuzzy topological space
- Authors: Morapeli, E Z
- Date: 1989
- Subjects: Fuzzy mathematics Fuzzy topology
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5393 , http://hdl.handle.net/10962/d1001982
- Description: Various notions of compactness in a fuzzy topological space have been introduced by different authors. The aim of this thesis is to compare them. We find that in a T₂ space (in the sense that no fuzzy net converges to two fuzzy points with different supports) all these notions are equivalent for the whole space. Furthermore, for N-compactness and f-compactness (being the only notions that are defined for an arbitrary fuzzy subset) we have equivalence under a stronger condition, namely, a T₂ space in the sense that every prime prefilter has an adherence that is non-zero in at most one point
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Educare work in Ciskei with special reference to the Keiskammahoek district
- Authors: Oosthuysen, Lucia
- Date: 1989
- Subjects: Educare , Education, Preschool -- South Africa -- Ciskei , Education, Primary -- South Africa -- Ciskei , Readiness for school -- South Africa -- Ciskei
- Language: English
- Type: text , Thesis , Masters , MEd
- Identifier: vital:1356 , http://hdl.handle.net/10962/d1001422
- Description: High drop-out rates in the sub-standards in developing countries prompted the researcher to investigate preschool education in first and third world countries, and attend to the related problem of school readiness. The rapidly expanding Educare preschool project in the rural area ot Keiskammahoek in Ciskei was investigated as an example ot community-based low-cost preschool education. A final sample of 41 children who had attended Educare Centres were matched to a control group on age, sex, primary school (where possible), and breadwinner's occupation. The Abbreviated Aptitude Test for School Beginners (standardised on Xhosa-speaking school beginners) was used to test tor significant differences between the two groups six to seven weeks atter school entry. A t-test was used on raw scores and chi-squared tests on staves. No signiticant difference was found between the means of the experimental and control groups. On a subjective rating scale for general-linguistic development and socio-emotional adjustment, no significant difference between means of the experimental and control groups was found. The experimental group's tailure to perform better than the control group, could be ascribed to various reasons, amongst others, the possible shortcoming that the pairs were not matched on intelligence, severe lack ot equipment in Educare Centres, large numbers of children in the majority of groups, uniform programmes for a wide age range, irregular attendance ot children, the low level of training of supervisors and poor home conditions. Scholastic abilities of school beginners in the Keiskammahoek District, as tested, were poor. Results deviated grossly from standardised norms. The expected percentage for the combined categories Very Weak and Weak is, tor instance, 31%; in this investigation, however, 73% of the testees fell in these two classes. Chronologically older children generally performed better. A highly significant difference existed between testees under six years and those over six years. This investigation indicated the need for better organised preschool education in rural areas in Ciskei. proposals with substantial financial implications are: Better training of para-professional staff by qualified staff. Training of qualified staff to provide expertise in preschool education in Ciskei. Provision of sufficient educational materials by Government subsidies and private sponsors. Institution of bridge classes by the Ciskei Department of Education to promote school readiness. Suggestions without financial implications include: An investigation of regulations regarding entrance age for basic education. Only in exceptional cases should children under six be admitted. Daily programmes in Educare Centres geared towards learning readiness without becoming academic. An age limit of three years for admittance to Educare Centres. Very young children should be catered for separately. Liaison between Sub A teachers and Educare staff. , Adobe Acrobat 9.53 Paper Capture Plug-in
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Effects of incremented loads over preferred values on psychophysical and selected gait kinematic factor
- Authors: Manley, Peter Gwynne
- Date: 1989
- Subjects: Psychophysiology , Kinematics , Work -- Physiological aspects , Human engineering
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:5160 , http://hdl.handle.net/10962/d1015734
- Description: This study investigated the effects of incremented loads greater than maximal acceptable loads on selected locomotor kinematic and psychophysical variables for four different hand-held load-carriage methods. Ten male and ten female subjects, between the ages of 18 and 30, participated in four experimental sessions. Data collection involved obtaining selected anthropometric, strength, maximal load and preferred load, gait kinematic, and psychophysical values. The anthropometric, strength and load capacity variables enabled absolute and morphology normalised sex-based comparisons to be made. The kinematic and psychophysical parameters were used to quantify any changes from two sets of baseline values,"unloaded" and "maximal acceptable load" values, when loads were increased and carrying methods changed. Statistical analysis revealed that males were taller, heavier and stronger than females (p<0.05). Males chose significantly greater maximal acceptable loads and absolute maximal loads than females when expressed in their absolute or relative terms. Preferred walking speeds were not significantly different for unloaded or loaded conditions, although males walked significantly faster in absolute terms (but not in relative terms) than females. Different load carrying methods and incremented loads brought. about significant changes to several of the kinematic parameters investigated. Finally, ratings of perceived exertion, as well as the number of exertion sites, were seen to increase significantly as load increased. These values were not, however, significantly affected by differences in load carriage method.
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Energetic and kinematic responses to morphology-normalised speeds of walking and running
- Authors: Williams, Martin Andrew
- Date: 1989
- Subjects: Running -- Physiological aspects , Walking -- Physiological aspects
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5166 , http://hdl.handle.net/10962/d1016240
- Description: This study investigated the influence of human morphology upon selected physiological, biomechanical and psychological responses to horizontal locomotion. In so doing, it was possible to evaluate the effectiveness with which morphology-normalised speeds of walking and running reduced the between-subject variability that is inherent in human locomotor responses. Twenty caucasian males were divided into two groups on the basis of stature - ten subjects in each of a "short" category (<170cm) and a "tall" category (>185cm). All subjects were habituated to treadmill locomotion prior to exposure to three walking treatments (0.83, 1.39 and 1.94m.s⁻¹) and three running treatments (2.50, 3.06 and 3.61m.s⁻¹). During each of these five-minute locomotor conditions, energetic (V02), kinematic (cadence and stride length) and psychophysical (central and local RPE) data were captured. From these data, lines of best fit were calculated for each subject, allowing for a prediction of the abovementioned locomotor variables from known absolute rates of progression. Using suitable regression equations, subject responses to morphology-normalised speeds of walking and running were effectively extrapolated. When the rate of progression was expressed in absolute terms (m.s⁻¹), significant differences (P <0.05) were found between the stature-related groups with respect to both energetic and kinematic locomotor responses. Such differences were successfully eliminated when use was made of locomotor speeds relativised on the basis of morphology. This study concludes that the use of appropriately prescribed morphology-normalised rates of progression are effective in reducing the variability in locomotor responses between subjects differing significantly in stature.
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Examining of the novel in the senior secondary phase (English first language higher grade): a study of conflicting aims
- Authors: Macrae, Claire Elisabeth
- Date: 1989
- Subjects: Education, Secondary English Secondary -- Study and teaching -- South Africa Education Secondary -- Evaluation
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1357 , http://hdl.handle.net/10962/d1001423
- Description: This study deals with the problems of external examining, the inflexible demands of which dominate and dictate to literature teaching in South African schools today. The aims of teaching literature are discussed, and it is suggested that the negative attitudes among pupils resulting from the present examining system defeat many of these aims. The opportunities for the enjoyment of literature are minimised by the process of preparation for external examinations. Creative teaching methods are abandoned in favour of coaching for specific types of questions, which are determined and limited by the practical constraints of a mass external examination. In catering to the demands for admininstrative reliability and efficiency, the educational validity and efficiency of the examinations are sacrificed. In Britain the Newbolt and Bullock Reports, among others, have made forceful recommendations for alternative approaches to external examining. Subsequently, much experimentation with internal examining, course-work and open-book examining has followed, aspects of which are discussed in this study. There has been limited experimentation in these areas in South Africa. The TED conducted a successful internal examining experiment in English literature, the results of which are considered in this thesis. The national English Olympiad open-book examination is a further example of the success of an alternative approach. By contrast, a comparison of examination papers set by the JMB and CED over the last ten years, shows clearly that the stated syllabus aims of teaching literature and the aims of examining the subject were wholly incompatible. Recommendations are made for the adoption of alternative examining strategies in order to address the shortcomings identified
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Family planning : an evaluative study on the attitudes and use of contraceptives by black males in Umtata
- Authors: Madikizela, Nosinodi Alicia
- Date: 1989
- Subjects: Birth control -- South Africa -- Transkei , Transkei (South Africa) -- Social conditions
- Language: English
- Type: Thesis , Masters , MSocSc
- Identifier: vital:3278 , http://hdl.handle.net/10962/d1006454 , Birth control -- South Africa -- Transkei , Transkei (South Africa) -- Social conditions
- Description: The purpose of this study is to identify, observe and record the attitudes and use to of contraceptives by black males in Umtata and to investigate the effect of education, urbanisation and age on fertility control. Data was gathered from a sample of adult males who were past the school going age and were employed or working in Umtata and its surburbs, which are Ngangelizwe, Ikwezi, Southernwood, Northcrest, Norwood, Ncambedlana, Nduli Crescent, Fortgale and Hill Crest. Information was also gathered from Nursing officers in charge of family planning service centres in the areas mentioned above. Findings reveal that, although black urbanised educated males in Umtata seem to have accepted the use of contraceptives by themselves and their sexual partners, their patterns of behaviour in relation to fertility control and the value of children to families remains traditional. This contributes to the relatively high fertility rate in the country. Children are an investment for old age. They are also regarded as a security factor against divorce. It is the duty of legally married couples to raise a family with children who will continue to bear the family name. It appears that men are either suspicious of modern contraception if not totally opposed to it. Many still prefer the use of natural methods of contraception. There is thus need for social workers and health planners to recognise and educate males on the use and benefits of modern contraceptives to limit the number of children borne and control periods when they would like to have children. This study will be of value to social welfare services and to family planning nurses who are in direct contact with clients in hospitals and clinics, in their family planning campaigns, when they motivate couples and individuals on the importance of family planning, and also in mother-and-child health services. Educationists, sociologists, psychologists and persons in other fields of study will also benefit from information attained in this survey.
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Health and politics : appraisal and evaluation of the provision of health and mental health services for Blacks in South Africa
- Authors: O'Donoghue, Sean B
- Date: 1989
- Subjects: Black people -- Mental health -- South Africa , Mental health services -- South Africa
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: vital:2909 , http://hdl.handle.net/10962/d1002074
- Description: The aim of this study has been to examine, in the light of recent events in the field of Health Care in South Africa, the remarks and claims made by the World Health Organization, and the American Psychiatric Association between 1976 and 1978 on Health Care services, as provided for Blacks, by the South African government. In two reports, these organizations instituted the earliest, and arguably most significant claims against South Africa's system of Health Care. This study sketches firstly the political genesis and social context of the WHO, and APA examinations. Secondly, this study evaluates responses made by the South African State to the critical climate inspired by the above mentioned reports, through a close analysis of recent events associated with the politics, and provision of Health Care Facilities - particularly with regard to Black South Africans. This analysis suggests that the governments' earlier tentative policy of privatisation (which was soundly condemned by WHO and the APA) has been even more enthusiastically pursued - in contradiction to it's avowed policies of Commu ity Health Care, and to the continuing detriment of those South African communities who are in most need of adequate Health Care services. The study concludes that the criticisms raised by the WHO and APA had the effect of inspiring positive reforms in South Africa's health services, but in no way thwarted the governments', at first only tentative plans, to increasingly privatise it's psychiatric and other medical institutions.
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High-performance liquid chromatographic studies of the acid degradation, pharmacokinetics and comparative bioavailability of erythromycin
- Authors: Glew, Fiona
- Date: 1989
- Subjects: High performance liquid chromatography , Erythromycin -- Analysis , Erythromycin -- Pharmacokinetics , Erythromycin -- Bioavailability
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3737 , http://hdl.handle.net/10962/d1001529
- Description: Erythromycin is a macrolide antibiotic with a spectrum similar to penicillin and is used mainly in the treatment of infections caused by gram-positive organisms. Since its discovery in 1952, erythromycin has achieved wide-spread clinical use. Susceptibility of erythromycin base to inactivation by acid results in decreased availability following exposure to acidic gastric fluids. Formulation of acid resistant dosage forms and the preparation of acid stable chemical derivatives have been attempted to improve absorption and subsequent clinical efficacy . Two of the most commonly used erythromycin derivatives are the stearic acid salt (erythromycin stearate) and the lauryl sulphate salt of the propionyl ester (erythromycin estolate). Although it has been known for many years that erythromycin is susceptible to acid degradation, very few reports on the stability of erythromycin in aqueous solutions appear in the literature. In this study, a high-performance liquid chromatographic system using electrochemical detection was employed for a kinetic study of erythromycin degradation. The effect of varying acid pH on the degradation rate of both erythromycin base and erythromycin stearate, and the effect on the hydrolysis rate of erythromycin estolate is presented. In addition, the effect of temperature on erythromycin degradation was also investigated. Until recently, the majority of pharmacokinetic and bioavailability studies have utilized relatively non-specific microbiological assay procedures. However, in this study a solid phase extraction, followed by the use of a high-performance liquid chromatographic system using electrochemical coulometric detection was employed for the determination of erythromycin in biological fluids. Human volunteers each received enteric coated erythromycin base pellets in capsule dosage form and also film coated erythromycin stearate tablets on separate occasions. Results from the clinical trials revealed the enteric coated erythromycin base pellets had a greater bioavailability than the film coated erythromycin stearate tablets. Computer fitting of data revealed no intra-volunteer variability in elimination rate constants, suggesting differences in serum levels following administration of both dosage forms are due to variation in absorption. Results from the clinical trials were also compared with those obtained from a further trial, during which the same volunteers received erythromycin estolate
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Identification and analysis of manual materials handling tasks within a commercial warehouse in South Africa
- Authors: Walraven, Lynne Louise
- Date: 1989
- Subjects: Materials handling -- Safety measures , Industrial safety -- South Africa , Lifting and carrying -- Safety measures
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:5159 , http://hdl.handle.net/10962/d1015722
- Description: Lifting and overstraining are major causative factors related to musculoskeletal injuries and low back pain. A great number of work-related injuries arise from the handling and/or mishandling of materials. Hence there is a need to quantify risk factors in situ and develop guidelines for safe lifting practises in industry. The aim of this study was to make appropriate in situ quantification, within a commercial warehouse, of the stresses and physical demands imposed on the worker when performing two handed lifts in the sagittal plane. The performance of employees was assessed under normal working conditions through an observational methodology of data collection. Task performance evaluation was based on detailed measurement of all containers handled, an activity and time analysis, and the 'Work Practices Guide to Manual Lifting’ (NIOSH, 1981) which was used as the primary guide to developing theoretical recommendations to probable MMH risk factors for the workers involved. Of the 191 tasks analysed 103 were deemed unsuitable. Appropriate task factor adjustments were made where necessary to both the frequency and Hfactors (horizontal distance between the centre of gravity of the container and that of the worker) in order to reduce the risk factor for the workers
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Interactions between ants, herbivorous insects and bracken (Pteridium aquilinum), a fern with extrafloral nectaries
- Authors: Rashbrook, Vanessa Karin
- Date: 1989
- Subjects: Arthropod pests -- South Africa Ants -- South Africa Ferns -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5592 , http://hdl.handle.net/10962/d1002042
- Description: Bracken (Pteridium aquilinum) is a cosmopolitan species of fern which possesses extrafloral nectaries. A survey of the arthropod fauna associated with the plant throughout its range in South Africa identified the most widespread and damaging bracken herbivores and those species most likely to be influenced by ants visiting the extrafloral nectaries. Seventeen herbivorous arthropods were found to be definitely feeding on bracken and a further thirteen species with a less certain status were recorded. In addition, several species of ants were observed on the fronds and feeding at the extrafloral nectarie. On the basis of their widespread distribution and abundance, four bracken herbivores emerged as being particularly detrimental to the plant in South Africa. They were an eriophyid gall mite, a leafhopper and two moths. The biology of the two lepidopterans, Appana cinisigna and Panotima sp., suggested that they were potentially vulnerable to ants at various stages of their life histories. Laboratory experiments were undertaken to observe ant-lepidopteran interactions under controlled conditions. The ant Crematogaster peringueyi rapidly removed exposed A. cini igna eggs, but did not appear to regard Panotima eggs as food items. Small instar larvae of both species proved vulnerable, but the larger larvae appeared capable of escaping ant predation. Ant exclusion experiments in the field, using natural and artificially augmented ant densities, were carried out at two sites near Grahamstown. The dominant ant species was C. peringueyi. Neither the numbers of lepidopterans nor levels of herbivory were significantly reduced by the presence of ants . Despite the implications of the laboratory tests, the results of these field experiments did not support the hypothesis that ants which visit bracken extrafloral nectaries benefit the plant. Ant-bracken field studies on other continents also reported no significant ant-related effects, though marginal reductions in the abundance of certain herbivores have been noted at one site in the U.K. Since ant protection does not appear to be an inevitable consequence of having extrafloral nectaries, their value to bracken is in some doubt. The most likely situation where effective protection will occur is when high densities of vulnerable herbivores are preyed upon by large numbers of aggressive ants. However, even under these conditions, enhancement of plant fitness is not inevitable. This raises the question of why extrafloral nectaries have been retained in a plant that is as successful and widespread as bracken.
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Investigation of the causative agents of the 1982 Gazankulu poliomyelitis outbreak, using four biochemical techniques
- Authors: Gibson, Katherine Margaret
- Date: 1989
- Subjects: Poliomyelitis -- Analysis , Poliomyelitis -- History -- South Africa , Poliomyelitis vaccine -- Analysis
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3878 , http://hdl.handle.net/10962/d1001612
- Description: Comparison of poliovirus strains was carried out to determine the origin of the virus in two isolates obtained during the 1982 outbreak of poliomyelitis in Gazankulu. Comparisons of the outbreak isolates with vaccine and wild-type strains of the same poliovirus type were carried out using four biochemical techniques. SDS-polyacrylamide gel electrophoresis (SDS-PAGE), two-dimensional thin-layer chromatography (TLC) and reversed-phase high-performance liquid-chromatography (RP-HPLC) were used for comparing viral capsid proteins. Comparison of poliovirus strains at a genetic level was carried out using two-dimensional oligonucleotide mapping of viral RNA. Results showed the type 1 poliovirus isolate, 5061, to be a novel wild-type poliovirus. The type 2 isolate, 5068, was closely related to the poliovirus type 2 Sabin vaccine strain, P712. It was concluded that the intrinsic variability of poliovirus strains was responsible for the appearance of isolate 5068
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Isolation, purification and effect of ligands on the nicotinic cholinergic receptor
- Authors: Kapp, Eugene Anthony
- Date: 1989
- Subjects: Ligands (Biochemistry) , Nicotinic receptors
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4550 , http://hdl.handle.net/10962/d1018235
- Description: The nicotinic cholinergic receptor protein of the fish electric organ, Torpedo fuscomaculata, has been isolated, purified and shown to represent a true model for the nAChR from other species and higher vertebrates. It is an integral membrane protein composed of four different subunits, tightly associated with other functional, but non-specific proteins. Purification of the nicotinic cholinergic receptor by chromatofocusing demonstrates an improved method over that of affinity and ion-exchange chromatography. Gel chromatography and SDS-polyacrylamide gel electrophoresis show evidence of four subunits; a(40-44 kDa), 6(53 kDa ),'Y(63 kDa) and 6(66 kDa) despite some degradation of receptor molecules by intracellular proteases. Spectrophotometric and fluorimetric studies of receptor-ligand interactions, show the functional and chemical integrity of the receptor to remain intact after solubilisation. The effect of cholinergic ligands on purified receptor preparations indicate quenching of the intrinsic fluorescence of the receptor. Agonists, like acetylcholine, bind and cause local conformational transitions, changing the active region from a hydrophobic to a hydrophilic environment. This phenomenon is illustrated by the 10-fold increase in fluorescence when the receptor is in a desensitised state. Antagonists, such as d-Tubocurarine, block this conformational transition. In vitro rectus abdominis muscle preparations . show the nitrosamines, dimethylnitrosamine and diphenylnitrosamine, to be true agonists of the nAChR. However their low affinity and specificity for the receptor precludes them as photoaffmity labelling agents. Photoactivation of dimethylnitrosamine occurs when associated with an acidic hydrogen at the active site of the receptor, suggesting energy-transfer labelling to be more facile than photoaffmity labelling. The membrane-bound receptor, in the presence of these nitrosamines, undergoes conformational transitions regulating the opening and closing of the ion-channel. Desensitisation and receptor activation are shown to involve one and the same molecular transition.
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Jean Dubuffet : a study of his concepts pertaining to the alienation of the artist
- Authors: Mather-Pike, Richard
- Date: 1989
- Language: English
- Type: Thesis , Masters , MFA
- Identifier: vital:21086 , http://hdl.handle.net/10962/6290
- Description: I decided on an investigation into the nature of Dubuffet's remarks concerning the plight of the artist in modern societies, believing that the difficulties facing the artist are, at the time of this writing, still in force, and perhaps even more so now than they were in his day. These difficulties I believe, arise in the form of curtailments on personal and aesthetic freedoms brought about as the result of the artist's position in, and conformity to, the norms and values of his society. The problem is I believe, that these value systems not only censor or curb artistic freedom but actually restrict all individual enterprises by demanding that the indi vidual conform to the greater wish of the group, at the expense of his own creative and individual potential.
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