A chemical investigation of Tulbaghia Violacea
- Authors: Burton, Stephanie Gail
- Date: 1990
- Subjects: Liliaceae , Plants -- Analysis
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4528 , http://hdl.handle.net/10962/d1015725
- Description: Tulbaghia violacea, a member of the family Alliaceae is indigenous to the Eastern Cape and is widely used as a herbal remedy for various febrile and gastro-enteric ailments, particularly in young children. Adverse effects, and even fatalities, have been reported following treatment with the plant extract. The project has involved synthesis of model compounds, chromatographic analysis of flavonoid and other constituents of the plant, and examination of the volatile components. Some fifteen flavones were synthesised as chromatographic models and in the course of this work, the development of a new method for synthesis of carboxylic anhydrides was completed. Use of the flavone standards permitted identification of the flavonols kaempferol and quercetin in hydrolysed glycosidic plant extracts. In addition, several sugars were identified, viz., D-glucose, D-fructose, L-arabinose and D-galactose as free sugars, and D-glucose, D-galactose , 1-rhamnose, D- fucose, D-xylose, 1-arabinose and D-fructose as glycosidic sugars, by g.l.c. and g. c. - m. s. analysis of derivatives of isolated sugar mixtures. The presence in the plant extracts of steroidal saponins was also demonstrated. The sulphur compounds, 2,4,5,7-tetrathiaoctane-2,2-dioxide and 2,4,5,7-tetrathiaoctane were isolated from the plant and characterised spectroscopically. This result, together with analysis of volatiles from the plant, has led to a proposal concerning the nature and origin of sulphur compounds in Tulbaghia violacea, showing close correlation with the sulphur compounds in Allium species. Investigation of the biological activity of Tulbaghia violacea extracts showed bacteriostatic activity, particularly of extracts which had not been heated, and which had been prepared from mature plants. Treatment of isolated smooth muscle preparations with Tulbaghia violacea extracts indicated the presence of a β-adrenergic agonist having an inhibitory effect on normal muscle contraction. The results of the investigations indicate that while there may be some basis for use of the plant as an antibacterial, or to treat colic, the adverse effects, caused possibly by the sulphur compounds and/or steroidal saponins present, may override the beneficial effects.
- Full Text:
A cross cultural investigation of gender: gender stereotypes of English and Xhosa undergraduate students
- Authors: Robinson, Kathryn Ann
- Date: 1990
- Subjects: Sex role -- South Africa -- Cross-cultural studies , Stereotypes (Social psychology) -- South Africa
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: vital:2901 , http://hdl.handle.net/10962/d1002065
- Description: This study begins with the assertion that gender-role stereotypes exist in society, and that these influence the way the members of society perceive themselves and others. These stereotypes consist of sex-typed personality traits, attitudes, interests and behaviours, and they vary to a greater or lesser extent according to the culture that they originate in. Just as ordinary members of society are influenced by these stereotypes, so too are researchers, although this is not something that is often readily admitted. A great deal of research has been undertaken on gender-roles in past years, but researchers have tended to re-use existing conceptualisations of gender without examining whether they are in fact salient for the culture or generation under study. This study begins with the premise that (in South Africa as much as anywhere) before truly accurate assessment of the distributions of gender roles in a culture can be initiated, the culturally specific content of its gender-roles must be discovered. This firstly involves the description of the culture's gender-role stereotypes. Such explication would hopefully also help researchers to avoid making biased interpretations as a result of the stereotypes. Secondly, the relationship between stereotypes and self-perceptions must be established to see if scales based on the former are valid for use on the latter. This study's aim was to begin to investigate these two areas in English and Xhosa students. 94 white English speaking, and 48 black Xhosa speaking undergraduate students responded to an open ended, and a Likert-type questionnaire on various traits, attitudes and behaviours, by rating each for the "typical" male and female as well as themselves. Descriptions of stereotypes and self-ratings were obtained from performing within culture t-tests, comparing ratings of typical males and females, and male and female self ratings. Data from the open ended questionnaires was used to fill out these descriptions, which were then compared across sexes and across cultures. Gender stereotyping proved to be salient in both cultures, and gender stereotypes of the two cultures shared some similarities but also had menaingful differences. In both cultures, stereotypes and self-descriptions paralleled one another in some areas, but also differed significantly. It was concluded that the same gender-role scale would not be equally valid for use in the two cuItures, and that scales based on stereotypes would not be altogether valid for assessing self-perceptions. Various issues and implications arising from the results are discussed critically, including the proposal for a redefinition of the terms "stereotype" and "culture" to suit South African society.
- Full Text:
A life-history approach to the biology of Oreochromis mossambicus (Pisces : Cichlidae) in the Eastern Cape, South Africa
- Authors: James, Nick, 1955-
- Date: 1990
- Subjects: Cichlids -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5187 , http://hdl.handle.net/10962/d1001963
- Description: The phenotypic plasticity of the cichlid Oreochromis mossambicus was examined in fresh and brackish water populations living in the eastern Cape near the southern extremity of the natural range. The primary goal of the study was to examine the wide variety of life-history styles which were expressed in relation to the varying environmental conditions. Four natural populations were studied during 1986 and 1987, and some experimental work under artificial conditions was carried out at the Rhodes University fishfarm during 1988. This comparative approach gave insights into the complex interactions between biotic and abiotic factors which are exploited by this hardy species. O. mossambicus displayed a wide variety of life-history tactics under harsh environmental conditions. The growth of juvenile fish was rapid and mortality of the young-of-the-year was high. Age at first onset of sexual maturity ranged from one to three years. Under harsh conditions growth rate was markedly reduced after maturity, which occurred during the second or third summer and growth disparity between the sexes was more pronounced. Longevity was found to vary from five to ten years for different populations. Under more favourable conditions (resembling the typical "floodplain" habitats of this species at lower latitudes) very rapid juvenile growth, and a high maximum mass of over 2300 g for both sexes was iii achieved. Sexual maturity under these conditions could be delayed until the third or fourth summer of life. O. mossambicus demonstrated an ability to withstand and even benefit from fluctuating water levels, and adjusted its life style according to the prevailing conditions: at times of high water level recruitment was low and sexual maturity delayed. During low water periods reproductive rates increased. Q. mossambicus showed a distinct preference for gentle gradients and well-vegetated habitats for feeding, nesting and refuge. During the study winter temperatures were near and at some times below the generally accepted lower limits for this species. This implies that these indigenous populations have a degree of cold tolerance. A further implication is that Q. mossambicus has the ability to thrive under adverse conditions which may partially explain its wide and successful colonisation of water bodies far from its natural range, and its obvious fisheries potential.
- Full Text:
A pilot study of commonly held misconceptions in secondary school genetics
- Authors: Moore, Aldyth Margaret
- Date: 1990
- Subjects: Genetics -- Study and teaching (Secondary)
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1338 , http://hdl.handle.net/10962/d1001404
- Description: This pilot study was aimed at investigating with the aid of a two-tier multiple choice questionnaire, the misconceptions held by pupils in standards 8 and 10 as well as first year Biology students in the area of senior secondary school genetics. It was found that certain of the children's preconceived ideas were altered by tuition while others were unaffected by either age or tuition and consequently warranted the name misconceptions. Four misconceptions were identified in this study and these were seen to be at the root of the difficulties experienced in genetics. They involved plants being seen to be unable to reproduce sexually, an inability to relate meiosis to genetics, a tendency to cling to the Punnett square algorithm when solving genetics problems despite a lack of understanding of the underlying processes and a failure to see the role of chance in genetics. These misconceptions were seen to have arisen because of certain preconceived ideas which hamper the formation of a suitable conceptual framework. The adoption of suitable teaching strategies appears to be the most likely method of rectifying the problem. However, before this can be regarded as conclusive, further research into the concept development of specific aspects such as sexual reproduction, needs to be done. Studies to investigate the most suitable teaching strategy should also be carried out as well as an investigation into the structure of the curriculum
- Full Text:
A preliminary appraisal of the mineral potential of Venda based on a reconnaissance geochemical soil sampling survey and literature review
- Authors: Wilson, Michael George Carey
- Date: 1990
- Subjects: Mines and mineral resources -- South Africa -- Venda
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4994 , http://hdl.handle.net/10962/d1005606 , Mines and mineral resources -- South Africa -- Venda
- Description: A reconnaissance soil sampling survey was carried out over Venda by Cycad (Pty) Ltd and the samples were analysed for 36 elements using XRF techniques, by Anglo American Research Laboratories in Johanuesburg. The data resulting from this survey forms the basis for the present interpretive study. Initially the sample positions were co-ordinated, then the geological, soil and sample types were allocated to each point. Twelve lithological groupings were chosen which incorporated most of the available data, retained significant geological characteristics and consisted of statistically significant sample populations. Statistical manipulation was undertaken for each of the lithological groups. Using a final population of 5768 samples, means were determined and anomalous values were identified using a threshold of mean plus two standard deviations. Due to time and budgetary constraints, 24 of the 36 elements were chosen for statisical manipulation and fourteen of these, with particular economic significance, were chosen for plotting, wherever significant numbers of anomalies were present. The element overlays were plotted so as to coincide with 18 of the 25, 1:50 000 topographic sheets covering Venda , the remaining 7 having inadequate sample coverage to yield meaningful contours. In this way a total of 175 element overlay sheets were plotted, each showing contoured element levels, with selected anomalous values. The treatment of the vast body of information made available by the Cycad sampling programme has thus been selective and has continually been aimed at highlighting and concentrating attention on the areas of greatest indicated mineralization potential, rather than on specific anomalies. In this regard it is felt that the present study has been successful, in spite of limited sample coverage in some areas. Combining the results of this study with a modern tectonically-based appraisal of mineralization potential and a knowledge of the local geology and previously known mineralization gleaned from an extensive literature review, the following types of mineralization are considered to have the highest potential in Venda: i) Nickel-copper-platinum mineralization as well as magnesite, in the olivine dolerite sills which intrude the base of the Karoo Sequence in Northern Venda. ii) Coal in the basal Karoo Sequence sediments in a broad zone from Jazz 715 MS in the west, and along the Klein Tshipise fault from Amonda 159 MT to the Mutale Copper Fields then east of these to the Kruger National Park. Where intrusives invade these lower Karoo sed iments the potential exists for amorphous graphite. iii) Hydrothermal copper and possibly gold and silver concentrations, in Nzhelele and Sibasa Formation rocks, particularly those associated with faults known to have been active in post-Soutpansberg times. iv) Sediment-hosted massive sulphide deposits (Cu-Pb -Zn) close to basin margin faults, near intersections with cross cutting faults that have resulted in localized basin formation. These are most likely in the Soutpansberg sediments. v) Martle, flake-graphite and late stage skarn mineralization (including lead, zinc, gold and tungsten), in calcareous rocks of the Gumbu Formation.
- Full Text:
A study of coeval sibling cannibalism in larval and juvenile fishes and its control under culture conditions
- Authors: Pienaar, Anthony Graham
- Date: 1990
- Subjects: Fishes -- Behavior , Fishes -- Larvae , Fish culture
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5781 , http://hdl.handle.net/10962/d1005469 , Fishes -- Behavior , Fishes -- Larvae , Fish culture
- Description: The primary objective of this study was to examine environmental parameters thought to affect cannibalism in certain fish species. It was found that environmental, behavioural, genetic and physiological factors all affect cannibalism in the species exhibiting the phenomenon. The diversity of factors nfluencing cannibalism served to illustrate the complexity of this behaviour pattern. Feeding to satiation was found to suppress cannibalism in catfish, trout and koi carp. High population densities were found to increase the rate of cannibalism, thereby acting as a population regulation mechanism for catfish, trout and the common and koi carps. Live food, as compared with dry pelletized feed was found to significantly suppress cannibalistic aggression. Catfish grown in total darkness, provided with refuges and living in turbid conditions were found to exhibit lowered cannibalistic and territorial aggression. Various lines of evidence suggested that cannibalism has a genetic basis, as was shown by the differences in cannibalistic behaviour of the two strains of Cyprinus carpio, viz. common and koi carp, with cannibalism being higher in the latter. This finding substantiates the hypothesis that cannibalism is genetically controlled and therefore open to evolutionary change. It is concluded that cannibalism is adaptive in times of food limitation, but that it is merely a by-product of normal feeding behaviour when food is abundant. Since cannibalism is advantageous and thus adaptive, the question arises ai to whether selection is occurring at the individual or the population level (or both). It was concluded that it is acting at the individual level, and that any benefits accruing at the population level iv were simply the effect of the initial cause, viz. individual selection. One of the aims of this study was to determine whether cannibalistic tendencies in fish are influenced by differing life history style trajectories. Based on the results of this study it is hypothesized that cannibalism is an r-selected trait. wi th the understanding gained from the knowl edge of the fundamental principles governing cannibalism, certain recommendations for its control in fish culture could be made. It is, however, imperative that further intensive studies be carried out to understand more fully this complex subject. General "rules" for regulating cannibalism could be helpful for any given cannibalistic species. However, in considering the differing life-history styles of each species, it becomes evident that species-specific guidelines need to be worked out. Until then, any suggestions for cannibalistic control offered to the aquaculturist can only serve as unrefined tools.
- Full Text:
A study of possible interactions between the pineal gland and the opioidergic system
- Authors: Khan, Razeeya B
- Date: 1990
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3729 , http://hdl.handle.net/10962/d1001468
- Description: Recent observations suggest a link between the pineal gland and the opioid system. Possible areas of interaction between the pineal gland and the opioidergic system in Wistar rats were investigated. The effect of opioids on the pineal gland in organ culture was monitored. Neither morphine, methadone nor the opioid antagonist naloxone was found to affect [¹⁴C]-serotonin metabolism by the pineal gland in vitro. Both the pineal gland and the opioid system are influenced by exposure to stressful stimuli. Morphine and melatonin had protective effects on stress-induced gastric lesions. The ability of melatonin to inhibit lesion formation was found not to be exerted via an opioidergic mechanism. Evidence has been obtained for a possible modulation of the stress response by the pineal gland . The opioid drugs are the most potent analgesic agents available. A possible interaction between the opioid system and the pineal gland in the modulation of the response to noxious stimuli was investigated. An intact pineal gland was found to be necessary for the manifestation of the nocturnally increased response of rats to noxious stimuli
- Full Text:
A study of real-time operating systems for microcomputers
- Authors: Wells, George Clifford
- Date: 1990
- Subjects: Operating systems (Computers) , Microcomputers
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4611 , http://hdl.handle.net/10962/d1004896 , Operating systems (Computers) , Microcomputers
- Description: This thesis describes the evaluation of four operating systems for microcomputers. The emphasis of the study is on the suitability of the operating systems for use in real-time applications, such as process control. The evaluation was performed in two sections. The first section was a quantitative assessment of the performance of the real-time features of the operating system. This was performed using benchmarks. The criteria for the benchmarks and their design are discussed. The second section was a qualitative assessment of the suitability of the operating systems for the development and implementation of real-time systems. This was assessed through the implementation of a small simulation of a manufacturing process and its associated control system. The simulation was designed using the Ward and Mellor real-time design method which was extended to handle the special case of a real-time simulation. The operating systems which were selected for the study covered a spectrum from general purpose operating systems to small, specialised real-time operating systems. From the quantitative assessment it emerged that QNX (from Quantum Software Systems) had the best overall performance. Qualitatively, UNIX was found to offer the best system development environment, but it does not have the performance and the characteristics required for real-time applications. This suggests that versions of UNIX that are adapted for real-time applications are worth careful consideration for use both as development systems and implementation systems.
- Full Text:
A study of the effects of the pineal hormone, melatonin, on dopaminergic transmission in the central nervous system of rats
- Authors: Burton, Susan Frances
- Date: 1990
- Subjects: Dopaminergic mechanisms Melatonin Pineal gland -- Secretions Neural transmission Pineal gland Nervous system
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3726 , http://hdl.handle.net/10962/d1001463
- Description: Dopamine mechanisms in the central nervous system are important in the control of both normal and abnormal motor function. The recent observations in both animal and human studies, that melatonin, the principal hormone of the pineal gland, may have a role in the control of movement and the pathophysiology of movement disorders, have given rise to the concept that melatonin may have a modulatory influence on central dopaminergic neurotransmission. This study makes use of three animal behavioural models as well as a biochemical model of central dopaminergic function to further investigate the concept. Results from studies using the biochemical model, which investigated the effect of melatonin on dopamine and apomorphine stimulation of dopamine-sensitive adenylate cylase, suggest that melatonin is neither a competitive antagonist nor agonist at the D₁ receptor level, although the possibility of physiological stimulation or antagonism is not excluded. In behavioural studies, prior melatonin mg/kg administration (1 and 10 (8M) ip) inhibited apomorphine induced stereotypy and locomotor activity in normal rats, and apomorphine-induced rotational behaviour in 6-hydroxydopamine and quinolinic acid lesioned rats. The possibility that these results may have physiological significance is borne out by the observation that, under enviromental lighting conditions that are associated with raised endogeous melatonin levels, apomorphine- induced stereotypy and locomotor activity is attenuated. The general conclusion is that melatonin has an inhibitory influence on central nervous system dopaminergic function, suggesting therefore, that the pineal gland and melatonin may have a role in the pathophysiology and treatment of movement and behavioural disorders associated with dopaminergic dysfunction
- Full Text:
An alternative peripheral executive for the data general AOS/VS operating system
- Authors: Tennant, Robert Satchwell
- Date: 1990
- Subjects: Operating systems (Computers) , Computers
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4566 , http://hdl.handle.net/10962/d1002031
- Full Text:
An analysis of some school history textbooks with special reference to styles of concept presentation
- Authors: Matoti, Sukude Mangwevandile
- Date: 1990
- Subjects: History -- Study and teaching -- South Africa -- Textbooks -- Evaluation , South Africa -- History -- Textbooks
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1343 , http://hdl.handle.net/10962/d1001409
- Description: The aim of this study was to find out whether the school history textbooks used in Transkei Junior and Senior secondary schools were adequate in helping pupils meet the demands of their course. The results of the study would be used as argument for or against the assumption that the type of textbooks used in Transkei schools, through their inadequacy in equipping the pupils with the necessary skills for "doing" history, do contribute to the high failure rate in history, especially that they are in most schools, the only recourse for both the teacher and the pupil. In particular the study intended to see what strategies the history textbooks used to aid concept understanding which is crucial to the understanding of history. Twenty three criteria, fourteen objective and nine subjective were used to assess the books for readability and for strategies which might aid concept understanding. Eight books were assessed: four Std 5 and four Std 8 books. The results showed that only three of the eight books catered for the development of skills of learning history and were suited to the level of the pupiils for whom they were intended . History textbooks therefore need to be improved so as to foster the skills of learning history. Their inadequacy could be a contributory factor to the high rate of failure. In-service and pre-service training in methods of textbook analysis can assist in textbook selection and for changes in methods of teaching to supplement shortcomings in books which are commonly used
- Full Text:
An analysis of the early ontogeny of Aplocheilichthys johnstoni (Günter, 1893) from a life history perspective
- Authors: Haigh, Eliria H
- Date: 1990
- Subjects: Ontogeny -- History , Cyprinodontidae , Aplocheilidae , Fishes -- History
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5217 , http://hdl.handle.net/10962/d1005060
- Description: The reproductive and developmental styles of Aplocheilichthys johnstoni closely resemble those of other oviparous cyprinodont fishes reported in the literature. Reproductively it sorts to the guild of nonguarding phytophyllic broodhiders, is a daily, fractional spawner of relatively large, adhesive eggs. The length of the embryonic period varies between 14 and 19 days and the larval period can last for up to 30 days. Sexual maturity can be attained at an age of 150 days from fertilization. The embryology is described in detail and close comparison is made with the embryology of other cyprinodonts to highlight possible phylogenetic differences. Major differences with other cyprinodonts are in the rate of development, and heterochronic shifts in the appearance of certain structures in relation to each other. A discussion is included on the nature of development. It is suggested that development proceeds in a gradual stepwise fashion, interspersed with four major saltations, namely, fertilisation, onset of exogenous feeding, sexual maturity and death
- Full Text:
An empirical phenomenological investigations of the experience of being unemployed : a critical study in the South African context
- Authors: Jaffray, Timothy William
- Date: 1990
- Subjects: Unemployment -- Psychological aspects , Unemployment -- South Africa -- Psychological aspects
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: vital:2904 , http://hdl.handle.net/10962/d1002068
- Description: Unemploynent is a problem that confronts many western countries. The aim of this dissertation is to understand, on the basis of a phenomenological investigation, what it means to be an unemployed, white, South African citizen. These meanings are then seen and discussed against the background of the problems associated with the ideological structure within the country. How the latter relates to white employment and psychological life is also explored. The results demonstrate the negative impact unemploynent has upon the psychological functioning of the individual. The results further show the despair such individuals face, having been 'denied' an accepted role within society.
- Full Text:
An examination of the achievement of the Jesuit Order in South Africa, 1879-1934
- Authors: Ryan, Judy Anne
- Date: 1990
- Subjects: Jesuits -- South Africa -- History Jesuits -- South Africa -- History
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: vital:2522 , http://hdl.handle.net/10962/d1001851
- Description: The Society of Jesus, founded in 1540 by St Ignatius of Loyola, dispatched the first group of five priests and three brothers to the Cape in 1875. Their destination was St Aidan's College (1875-1973) in Grahamstown which they would staff. Two of the priests went to Graaff-Reinet where the Society established a mission house and noviciate (1875-1889). On 1 July 1878 the Zambesi Mission was founded with Henry Depelchin as its appointed leader. The Mission was placed under the direct control of the Jesuit General. St Aidan's became the headquarters of the Zambesi Mission and it was hoped that trainees for the Mission would emerge from the College. The first group of missionaries bound for the Zambesi regions left Grahamstown in 1879. Negotiations followed with the Ndebele chiefdom in Bulawayo and stations were established at Tati, Empandeni and Pandamatenga. Unsuccessful probes into Barotseland and Gazaland followed and a decade later the mission to Zambesia was abandoned and the Jesuits returned to the south where there had been further expansion of the Order's activities. Dunbrody (1882-1934), situated on the Sundays River, had been set up as a base for the Zambesi Mission, as an educational centre for Blacks and as a farm. Keilands (1886-1908) was an attempt to establish a missionary base for the extension of activities into the Transkei. Vleischfontein (1884-1894) in the Western Transvaal, was developed as a staging post between Zambesia and the Cape. In 1924 the Order attempted to develop parish work in Claremont, but initially nowhere else. By 1890 the Jesuits were ready to return to Matabeleland and in the post colonial years a string of stations were founded. Partly to conserve its manpower for the Zambesi enterprise and for financial and economic reasons, Graaff-Reinet was abandoned in 1889, followed by Vleischfontein, Keilands, the parish at Claremont, and Dunbrody. By 1934, the terminal point of the thesis, the only Jesuit presence in South Africa was at St Aidan's which was saved from closure by Papal intervention.
- Full Text:
An investigation into some learning and teaching problems of biology in Transkei senior secondary schools
- Authors: Matoti, Sheila Nokuthula
- Date: 1990
- Subjects: Education, Secondary Biology -- Study and teaching
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1349 , http://hdl.handle.net/10962/d1001415
- Description: The aim of this study was to investigate some learning and teaching problems of biology in Transkei Senior Secondary schools. The research focussed mainly on Biochemistry. Biochemistry was treated in the context of biology as a whole to show its relevance to other sections of the syllabus. Questionnaires were administered to standard 10 pupils in 15 senior secondary schools selected randomly from the Central Region of Transkei. Further information on pupils' understanding of concepts taught in Biochemistry , was gained through use of concept tests and concept maps. Interviews were conducted with standard 9 and 10 biology teachers, Subject committee members, Examiners, Subject advisers, Lecturers from the University of Transkei and the Transkei Teachers' In-service College and pupils. Data obtained through the use of those research methods was analysed and discussed. Concept mapping as a teaching strategy was introduced to some standard 9 and 10 teachers who attended courses (biology) at The Transkei Teachers ' In-service College. Some suggestions and recommendations for the learning and teaching of biology were then made
- Full Text:
An investigation into some of the problems affecting the teaching and learning of biochemistry in Transkei Colleges of Education
- Authors: Qokweni, Patiswa
- Date: 1990
- Subjects: Biochemistry -- Study and teaching -- South Africa -- Transkei
- Language: English
- Type: text , Thesis , Masters , MEd
- Identifier: vital:1350 , http://hdl.handle.net/10962/d1001416
- Description: The study investigated some of the problems experienced in the teaching and learning of biochemistry - a section in the Senior Certificate biology syllabus - in the Transkei Colleges of Education. Biochemistry is often labelled a difficult area, therefore, the study was an attempt to identify the problems encountered by biology teachers and lecturers in teaching biochemistry and by student-teachers in learning it. Questionnaires were admlninistered to final-year biology major student-teachers in the colleges, and to the biology teachers and college lecturers. Examiners and subject advisers for biology were interviewed. The questionnaires required the respondents to identify the following: 1. Areas of biochemistry they find difficult. 2. Areas of biochemistry they find easy to understand. 3. Possible reasons for the students' poor performance in biochemistry. 4. Possible suggestions for improvement. The student-teachers were further given a concept test to test their understanding of the concept 'photosynthesis'. After analysing the data, the findings were used to make some recommendations, in an attempt to improve the teaching of biochemistry by the teachers and lecturers and of the learning of biochemistry by the students
- Full Text:
An investigation into the nature and extent of erosion and sedimentation in the Maqalika Dam catchment, Maseru
- Authors: Ntsaba, 'Mankone 'Mabataung
- Date: 1990
- Subjects: Erosion -- Lesotho Sedimentation and deposition -- Lesotho Land use -- Lesotho -- History River sediments -- Lesotho
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4799 , http://hdl.handle.net/10962/d1001899
- Description: The study investigates the nature and extent of erosion and deposition in the Maqalika catchment, Maseru. Components of the study include (i) the re-construction of erosion and land use history in the catchment from 1961 to 1985, (li) determination of dominant factors or combinations of factors responsible for the observed erosion distribution at each date, (iii) the identification and evaluation of erosion and deposition features, and their spatial and temporal variations, and (iv) identification of socia-economic problems associated with observed erosion and deposition. Methods employed for the re-construction of erosion and land use history include the use of sequential aerial photography of 1961, 1979 and 1985, orthophoto maps and review of literature from past studies. It has been possible to map erosion and land use for the three time periods pinpointing areas of major change. Results are presented in map form showing the spatial distribution of each erosion class and each land use category. It was however not possible to derive any meaningful relationship between erosion distribution and land use, on the aforementioned maps. The only observation made from the comparison of the maps is that erosion degree and distribution sometimes changes with land use, while land use sometimes changes in response to erosion. Major land use changes are the conversion of agricultural land to urban land use, and grazing land. Due to the mnlti-dimensional nature of soil erosion, hand 'actor analysis was employed to determine which factors or combinations of factors were dominant at each date. Despite the extensive research on the various factors affecting erosion such as those used for the USLE and SLEMSA there is a growing uncertainty as to which factors are more important to erosion. Soil erodibility has been found to be a component of the major controlling factor combinations in all three periods under study. At each date erodibility combined with a number of other factors determined the observed erosion distribution. As suggested by Mosley (1980), Cambell (1985) and Coleman and Scatena (1986) sediment from a catchment is derived principally from spatially limited portions of the catchment. Likewise eroded sediment becomes deposited in spatially limited areas with special characteristics which encourage deposition. Aerial photographic survey aided by ground survey and oblique photographs were employed to identify sediment sources and sinks within the catchment. Some sediment sources are fIxed such as gully floors and sides, while some change location from time to time such as construction sites. An evaluation of portions of the catchment for their ability to supply and deliver sediment has shown that the most eroded areas are not the most active sediment sources. Sediment yield is limited by either supply or transport. Sediment yield was estimated using reservoir survey data which indicate that there is a high rate of soil loss from the catchment. One flaw of this method as a measure of soil loss is that it treats the measured sediment yield as if it were contributed uniformly from the basin. This method however affords the researcher to estimate minimum erosion rates, taking into account that large amounts of sediment are stored at various places within the catchment. The possible socio-economic consequences of erosion and deposition have been identified. These include loss of cropland, destruction of roads and building sites which require methods of reclamation, sedimentation of small reservoirs and ponds, and the formation of gully bottom fills which are potential sediment sources. Conservation measures presently applied in the catchment are assessed and found to be irrelavant to the present erosion problem. Data from the reservoir survey revealed that the estimated rate of soil loss is more important to on-site erosion damage than to off-site damage in the form of the sedimentation of Maqalika reservoir. Appropriate conservation measures such as those suggested by Amimoto (1981) would be relevant to the study area, however the main constraint in their implementation would be lack of legislation and the absence of a sound land use policy. It is therefore concluded that the present land use situation which does not take into consideration the physical constraints of the catchment is partly responsible for accelarated erosion in the catchment.
- Full Text:
Dealing with distress: a medical anthropological analysis of the search for health in a rural Transkeian village
- Authors: Simon, Christian Michael
- Date: 1990
- Subjects: Medical care -- South Africa -- Transkei -- Jotelo , Poor -- Health and hygiene -- South Africa -- Transkei , Transkei (South Africa) -- Economic conditions
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2082 , http://hdl.handle.net/10962/d1001599
- Description: This study aims to characterize and understand the search for health in a rural Transkeian community. It begins with the observation that the people of Jotelo have to negotiate considerable hardships in their daily lives. These hardships include the impact of malnutrition, undernourishment and a wide range of diseases like tuberculosis, typhoid and gastro-enteritis. To survive ill-health, people develop numerous practical strategies. Most significantly, they attempt to maximise availalble resources, like cash, their relations with others and local medical facilities. Hence the study attempts to characterize how and why patients select various kinds of therapy in their search for health. By focusing on patients' recourses to treatment, the study reveals that the search for health is as much a personal experience as it is a social and economic one. This idea is developed in an analysis of the links betw'een work, illness and social reproduction. The point which emerges from this discussion captures the central theme of the study: the search for health is a profoundly personal, social and economic experience. This notion is strengthened by an examination of the historical and contemporary nature of local health and health care. It is observed that health and health care is intimately linked to the local and wider political economy. This not only serves to contextualise the discussion on patients' actual experiences, but points to the fact that these experiences are part of wider processes. By depicting the search for health in this way, the study hopes to have illustrated what people do in times of illness and why. Yet it also claims to have gone beyond such a depiction. By abstracting from its findings, it aims to conclude that the search for health is not merely caused by various local and wider processes, to which it has referred. In other words, it hopes to avoid a deterministic view of patients' experiences in times of distress. Instead, it is argued that the search for health is ultimately an integral part of the local and wider economic and political environment
- Full Text:
Enrichment strategies for gifted English first language (HG) pupils at the senior secondary level : a critical evaluation of a programme implemented at Grey Boys' High School, Port Elizabeth, 1986-1988
- Authors: Cunningham, Gregory Mark
- Date: 1990
- Subjects: English language -- Study and teaching (Secondary) -- South Africa -- Eastern Cape Gifted children -- Education (Secondary) -- South Africa -- Eastern Cape Gifted children -- Education -- Research
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1510 , http://hdl.handle.net/10962/d1003392
- Description: Programmes developed specifically for the gifted and talented pupil are not a novel idea. Yet, by comparison, the history of gifted education is a brief one. Highly gifted and talented pupils often have difficulty being challenged in a conventional classroom situation. Since classroom instruction is usually designed for the benefit of pupils who function at the level of the majority of their peer age-group, this teaching, no matter how well done, may not be appropriate for the extremely gifted pupil whose abilities differ greatly from this group. Even special programmes for gifted and talented students may be designed for a broad group of gifted students and may not meet the specific needs of the gifted child, especially ones with a special intellectual talent. While it is important to bear aspects such as the characteristics of giftedness and the attributes of the talented individual in mind, the basis of this dissertation examines what enrichment and acceleration strategies may be utilised by the English First Language (HG) teacher when presented with a preselected group of pupils who are gifted in English, utilising a composite gifted educational model as a mechanism for the development of this specific programme.
- Full Text:
Household, production and the organisation of cooperative labour in Shixini, Transkei
- Authors: Heron, Gavin Stewart
- Date: 1990
- Subjects: Xhosa (African people) , Agriculture -- South Africa -- Transkei , Agriculture, Cooperative -- South Africa -- Transkei , Cooperative societies -- South Africa -- Transkei
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2109 , http://hdl.handle.net/10962/d1007448 , Xhosa (African people) , Agriculture -- South Africa -- Transkei , Agriculture, Cooperative -- South Africa -- Transkei , Cooperative societies -- South Africa -- Transkei
- Description: Incidences of cooperation in agricultural activity are widespread phenomena in low-income third world communities. Two forms of cooperative labour groupings are identified in Shixini, Transkei . These are the work party and the ploughing company. It is argued that different organisational principles operate in the different cooperative forms. Work parties are based on principles of neighbourhood whi Ie ploughing companies are organised around kinship relationships. Factors which determine the principle of organisation are social values; the wider South African economic system; ecology; reciprocity; the constitution and structure of the household; economic differentiation; and labour demand and supply. The dissertation is divided into five chapters. The first is an overview of the Shixini social, economic and political systems. This chapter discusses the influence of the wider South African politico-economic system on agricultural production; the Shixini!Transkei political context; kinship and its relation to social organisation; and the likely effects of an agricultural 'betterment' scheme on the area. The second chapter is an overview of agricultural production in Shixini. It is found that the most significant determinants of agricultural production is the structure and constitution of the household and the way in which stock is distributed in the community. The third and fourth chapters describe and analyse Xhosa work parties and ploughing companies . Argument is lead as to the reasons for the specific organisational principles operating in each case. The penultimate chapter is an analysis of sacred and secular ritual. It is argued that both ritual forms reveal cooperative principles of organisation. Secular ritual dramatises the organisation of work parties while sacred ritual dramatises kinship relationships and so, the organisation of ploughing companies. , KMBT_363
- Full Text: