A case study of English/Xhosa code switching as a communicative and learning resource in an English medium classroom
- Authors: Marawu, Sithembele
- Date: 1997
- Subjects: Code switching (Linguistics) -- South Africa Language and education -- South Africa Education, Bilingual -- South Africa
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1436 , http://hdl.handle.net/10962/d1003317
- Description: Research on code switching (CS), the use of more than one language in a single piece of discourse, has focused on various aspects of the phenomenon. For example, research has concentrated on switching that occurs between turns of interlocutors in a piece of discourse, sometimes between sentences within a single tum and sometimes within a sentence. Researchers have approached this discourse behaviour from various perspectives. For instance, some investigate the social functions of the switches, others explore the linguistic constraints on the switches. Furthermore, most of this research has examined CS in non-educational contexts. Research on classroom CS, the focus of this study, took hold in the mid 1970s. Researchers began to investigate the communicative functions of CS and the frequency with which teachers and learners used certain languages to perform different functions. Recent studies on classroom CS focus on the sequential flow of classroom discourse and "the way in which codeswitching contributes to the interactional work that teachers and learners do in bilingual classrooms" (Martin-Jones 1995:91). The approach used in these studies is the conversational analytic approach grounded in ethnographic observation. In South Africa little research has been done on classroom CS, though it makes an important contribution to the interactional work of teachers and learners in classrooms. This study explores the use of English and Xhosa in the classroom as a learning and communicative resource. Its focus is on the communicative functions of the switching behaviour of a teacher as she interacts with her pupils. In other words, this study looks at how the research subject uses English and Xhosa to get things done in the classroom. As the classroom situation observed is dominated by the teacher, this study concentrates mainly on her communicative repertoire. It does not attempt a full linguistic description of the switches made by the research subject, for example, it does not deal with linguistic constraints on CS. One of the major findings noted in this study is that the research subject does not use CS so as to avoid using English. She uses CS as a learning resource. It has also been noted that CS is used by the research subject as a contextualisation cue, for example, we noted the way it co-occurs with other contextualisation cues like nonverbal communication cues. This is in line with Martin-Jones' (1995) viewpoint that CS is not used by bilingual teachers simply to express solidarity with the learners but to negotiate and renegotiate meaning.
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- Date Issued: 1997
A case-study of principal succession : the experience of a high school principal and staff
- Authors: Dowding, Susan Patricia
- Date: 1997
- Subjects: Educational leadership School principals -- South Africa
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1440 , http://hdl.handle.net/10962/d1003321
- Description: This is a study of a principal succession In a non-racial, multicultural High-School in the North West Province of South Africa, formerly the independent homeland known as "Bophuthatswana". I was employed at the school at the time and am, therefore, a complete member-researcher. I use a qualitative research approach which relies mostly on in-depth interviews, individually and in groups. I chose my sample by administering a short biographical questionnaire. I have sought to establish "what is happening?" in the succession process by reporting the insights and experiences of a staff and its new principal. While I use the stage frameworks of more traditional researchers in succession to provide a coherent structure for my analysis, I use the organisational socialisation perspective extensively to analyse the insights provided by the staff and principal. Unlike other principal succession studies, I include the insights of both the principal and the staff. The organisational socialisation approach emphasises that succession is an interactive, multidirectional process. My study reinforces many of the observations of other researchers in leadership succession, whether in business or Education. However, two elements of succession emerge which appear to be unique in terms of other succession literature. These elements include the impact of socio-political events and what I call "ethno-cultural" aspects on the succession socialisation process. I provide examples of the influence these factors exert in this principal succession. This study is therefore of potential significance to administrators in both Education and business in the South African context where there are significant changes taking place in the power structures and ethnic makeup of relevant organisations. I also identify a number of areas for further research.
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- Date Issued: 1997
A collated digital, geological map database for the central Namaqua Province using geographical information system technology
- Authors: Holland, Henry
- Date: 1997
- Subjects: Geographic information systems , Namaqua Province (South Africa) -- Maps Databases , Geology Maps , Cartography
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4936 , http://hdl.handle.net/10962/d1005548 , Geographic information systems , Namaqua Province (South Africa) -- Maps Databases , Geology Maps , Cartography
- Description: The genlogy of the Namaqua Province is notoriously difficult to map and interpret due to polymetamorphic and multiple deformation events and limlted outcrop. Current maps of the Province reflect diverse interpretations of stratigraphy as a consequence of these difficulties. A Geographic Information System is essentially a digital database and a set of functions and procedures to capture, analyse and manipulate spatially related data. A GIS is therefore ideally suited to the study and analysis of maps. A digital map database was established, using modem GIS technology, to facilitate the collation of existing maps of an area in the Central Namaqua Province (CNP). This database is based on a lithological classification system similar to that used by Harris (1992), rather than on an interpretive stratigraphic model. In order to establish the database, existing geological maps were scanned into a GIS, and lines of outcrop and lithological contacts were digitised using a manual line following process, which is one of the functions native to a GIS. Attribute data were then attached to the resultant polygons. The attribute database consists of lithological, textural and mineralogical data, as well as stratigraphical classification data according to the South African Committee for Stratigraphy (SACS), correlative names assigned to units by the Precambrian Research Unit, the Geological Survey of South Africa, the Bushmanland Research group and the University of the Orange Free State. Other attribute data included in the database, are tectonic and absolute age information, and the terrane classification for the area. This database reflects the main objective of the project and also serves as a basis for further expansion of a geological GIS for the CNP. Cartographic and database capabilities of the GIS were employed to produce a collated lithological map of the CNP. A TNTmipsTM Spatial Manipulation Language routine was written to produce a database containing two fields linked to each polygon, one for lithology and one for a correlation probability factor. Correlation factors are calculated in this routine from three variables, namely the prominence a worker attached to a specific lithology within a unit or outcrop, the agreement amongst the various workers on the actual lithology present within an outcrop, and the correspondence between the source of the spatial element (mapped outcrop) and the source of the attribute data attached to it. Outcrops were displayed on the map according to the lithology with the highest correlation factor, providing a unique view of the spatial relationships and distribution patterns of lithological units in the CNP. A second map was produced indicating the correlation factors for lithologies within the CNP. Thematic maps are produced in a GIS by selecting spatial elements according to a set of criteria, usually based on the attribute database, and then displaying the elements as maps. Maps created by this process are known as customised maps, since users of the GIS can customise the selection and display of elements according to their needs. For instance, all outcrops of rock units containing particular lithologies of a given age occurring in a specific terrane can be displayed - either on screen or printed out as a map. The database also makes it possible to plot maps according to different stratigraphic classification systems. Areas where various workers disagree on the stratigraphic classification of units can be isolated, and displayed as separate maps in order to aid in the collation process. The database can assist SACS in identifying areas in the CNP where stratigraphic classification is still lacking or agreements on stratigraphic nomenclature have not yet been attained. More than one database can be attached to the spatial elements in a GIS, and the Namaqua-GIS can therefore be expanded to include geochemical, geophysical, economic, structural and geographical data. Other data on the area, such as more detailed maps, photographs and satellite images can be attached to the lithological map database in the correct spatial relationship. Another advantage of a GIS is the facility to continually update the database(s) as more information becomes available and/or as interpretation of the area is refined.
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- Date Issued: 1997
A comparative photostability study of four propyl piperzine-substituted phenothiazines
- Authors: Drummond, Patricia Mary
- Date: 1997
- Subjects: Phenothiazine
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3756 , http://hdl.handle.net/10962/d1003234 , Phenothiazine
- Description: Four structurally related phenothiazines available in South Africa in a variety of dosage forms and as fine chemicals were investigated to ascertain whether their structural differences in terms of the 2-chloro-/ trifluoromethyl-substituents on the phenothiazine nucleus and the methyl-/ ß-hydroxethyl groups on the piperazine ring accouning for the differences in pharmacological activity can be correlated with their photostability².The four propyl piperazine-substituted derivatives are ranked in the following decreasing order of neuroleptic activity: fluphenazine> trifluoperazine> perphenazine > rochlorperazine. In order to assess their photostability an HPLC method was developed and validated for linearity, accuracy and precision, selectivity, limit of detection and quantitation and ruggedness. Preliminary solution photostudies under controlled light conditions (UV, sunlight, fluorescent light) indicated that the rate of degradation followed first-order kinetics with perphenazine the most susceptible to.photodegradation under all light conditions studied. In vitro and in vivo metabolism yielding the 5-sulphoxide and its reported presence on decomposition of the phenothiazines25 led to the development of a synthetic procedure suitable for the sutphoxides of all four derivatives based on the method proposed by Owens et al. in order to provide standards for comparison in the photostudies⁷. Since ICH regulations require that impurities> 0.1 % are examined and identified⁷⁴ and semi-preparative isolation of photoproducts proved unsuccessful, LC-MS having been well documented for structural.elucidation⁷⁵ ⁷⁵ ⁷⁶ ⁷⁷ was used to characterize solution (UV, sunlight, fluorescent light) and preliminary solid (UV) photostudies. The chloroderivatives underwent dechlorination and sulphoxidation with subsequent photosubstitution in the case of prochlorperazine to yield the 2-hydroxy derivative and sulphoxidation of the dechloro-derivative of perphenazine. The sulphoxides of both trifluoperazine and fluphenazine were formed with further oxidation to the respective sulphones occurring. Preliminary solid state (UV) photostudies showed fluphenazine to be the least stable with 30.71 % degradation as opposed to 7.57% for prochlorperazine, 4.28% for perphenazine and 7.10% for trifluoperazine witn sulphoxidation observed to be. the major degradation pathway. Since in vitro metabolism of perazine derivatives is reported to occur via N-oxidation, N-demethylation, sulphoxidation and aromatic hydroxylation¹⁸ it does appear that there is some correlation between metabolic and photoproducts. However the fact that solution (UV) photostudies indicates trifluoperazine to be the most and perphenazine the least stable does not concur with the proposed order of pharmacological activity.
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- Date Issued: 1997
A comparative study of the Grey-headed Sparrow (Passer griseus L) and the House Sparrow (Passer domesticus L) in Malawi
- Authors: Nhlane, Martin Edwin Darwin
- Date: 1997
- Subjects: English sparrow Sparrows
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5654 , http://hdl.handle.net/10962/d1005337
- Description: The House Sparrow Passer domesticus, an introduced species, and the Grey-headed Sparrow Passer griseus, an indigenous species, are sympatric in Malawi. Their distribution in the country and any possible interactions were studied, principally in southern Malawi. A morphological analysis of museum specimens confirmed that grey-headed sparrows in Malawi belong to the Northern Grey-headed Sparrow Passer griseus as distinct from the Southern Grey-headed Sparrow Passer diffusus. This species was widely distributed in the, country in association with human dwellings, both in rural areas as well as urban centres. In the northern region Greyheaded Sparrows were more abundant in the urban centres than rural areas, but in the central and southern regions numbers in the rural and urban areas were more or less the same. In Blantyre City, where they are in sympatry with the House Sparrow, they were found in the low density and industrial areas and were absent from the high density areas. The House Sparrow, arrived in Malawi in 1967 at Chileka in the southern region. Since then it has spread northwards, moving from the southern to the central and northern regions. House Sparrow numbers were found to be progressively larger in the southern region and lowest in the northern region. House Sparrows were found at sites where food was readily available, as in the immediate vicinity of houses. In the central and northern regions they were restricted mainly to urban areas. In the southern region, they occur both in rural and urban areas, probably as a reflection of the larger period of colonization in the south. In the northern region their movement has apparently been restricted by geographical barriers. In Blantyre City Grey-headed Sparrows preferred areas where tree density was high and house density was low, while House Sparrows preferred areas where house density was high and tree density was low. There was a positive correlation between Greyheaded Sparrow numbers and tree density and a negative correlation with house density. House Sparrow abundance was negatively correlated with tree density and positively correlated with house density. Grey-headed Sparrows bred in the rainy season, whereas House Sparrows bred throughout the year. There were differences in nest site selection: Grey-headed Sparrows used artificial structures such as fencing poles, and wooden telephone or electricity poles. The House Sparrow used mostly buildings and nested in crevices, holes in walls and between the walls and rafters. Nest height also differed- Grey-headed Sparrows nested at heights ranging from 1 - 8 m while House Sparrow nests were at heights of 1 - 5 m. Moult data suggests that although the House Sparrows breed throughout the year, they moult at a particular time of the year when breeding is less common. Grey-headed Sparrows were found to moult mainly from May to September in southern Africa and from June to September in central Africa. In both cases the breeding season extends over a similar period from about October to April/May of the following year. Peak moult periods differed between the House Sparrows and Grey-headed Sparrows. House Sparrows moulted mainly in the first half of the year, and Greyheaded Sparrows in the second six months. The clutch sizes of the two species were similar (mean 3.9 eggs for the House Sparrow and 3.4 for the Grey-headed Sparrow). The clutch size of the House Sparrow varied seasonally and was larger from November to May. The average incubation period for the House Sparrow was 11.5 days and the fledging period 15.4 days. The Grey-headed Sparrow fledging period was 14.7 days. Chick mortality of the House Sparrow at Chikunda farm was attributed to starvation resulting from brood reduction, abandonment, predation, low birth weight, accidental deaths and parasitism by fly larvae. Both Grey-headed and House Sparrows fed their young on insect food. Male House Sparrows fed actively initially, but their contribution declined from about day five onwards. In the Grey-headed Sparrow, both parents fed their young equally throughout the nestling period. House Sparrows fed on the ground near houses; Grey-headed Sparrows fed both on the ground away from houses and in tree canopies. The Grey-headed Sparrow walked as it fed on the ground as opposed to the House sparrow which hopped. Grey-headed Sparrows fed mainly as pairs and singletons while House Sparrows fed as family groups. Larger feeding groups of Grey-headed Sparrows were seen in the northern region at areas where food was plentiful. Where the two sparrows were seen feeding together, there was no direct competition for food. Where individual distance was violated; male House Sparrows displaced Grey-headed Sparrows which landed too close to them. Overall it appears that the distribution of the two species is determined more by their responses to habitat conditions than by interspecific interactions.
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- Date Issued: 1997
A critical investigation of the Primary Schools Nutrition Programme (PSNP) in the Eastern Cape
- Authors: Houston, Elizabeth Margaret
- Date: 1997
- Subjects: Operation Hunger (Organization) , Primary schools nutrition programme -- South Africa , Non-governmental organizations , School children -- Food -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2783 , http://hdl.handle.net/10962/d1002993 , Operation Hunger (Organization) , Primary schools nutrition programme -- South Africa , Non-governmental organizations , School children -- Food -- South Africa
- Description: The thesis focuses on the Primary School Nutrition Programme (PSNP), particularly in the Eastern Cape, as a government nutrition and education project, and its failure to achieve its stated goals. The programme experienced problems almost as soon as it was introduced. The press reported incidents of fraud and maladministration and the programme was halted and restarted numerous times. The thesis seeks to offer some insight as to why the government was unable to reach its stated objectives in the implementation phase of the programme. State theory informs the thesis in an attempt to further explain why governments often seem unable to attain their intended goals. The thesis provides an alternative to government development programmes, arguing that NGOs are better equipped to deal with the particular problems that people on the ground experience when dealing with issues like nutritional vulnerability. Operation Hunger provides an excellent case study for how development of this nature ought to occur. The essential argument of the thesis is that there is an inherent tension between what a government's stated intentions is and what, it, in reality, intends to gain from such programmes. It is the contention of this thesis that the Government of National Unity embarked on the PSNP, not to ensure nutritional development for its own sake, but rather to curry favour with its constituents. Operation Hunger, and other organisations like it, provide relief to vulnerable communities with no hidden agenda in mind. Their mandate is solely that they provide assistance. The thesis argues, then, that NGOs have a role in domestic and international politics, that they can make up for or do better, or at least well, things that governments struggle to do.
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- Date Issued: 1997
A new empirical model for the peak ionospheric electron density using neural networks
- Authors: McKinnell, L A
- Date: 1997
- Subjects: Ionospheric electron density Neural networks (Computer science)
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5478 , http://hdl.handle.net/10962/d1005264
- Description: This thesis describes the search for a temporal model for predicting the peak ionospheric electron density-(foF2). Existing models, such as the International Reference Ionosphere (IRI) and 8KYCOM, were used to predict the 12 noon foF2 value over Grahamstown (26°E, 33°8). An attempt was then made to find a model that would improve upon these results. The traditional method of linear regression was used as a first step towards a new model. It was found that this would involve a multi variable regression that is reliant on guessing the optimum variables to be used in the final equation. An extremely complicated modelling equation involving many terms would result. Neural networks (NNs) are introduced as a new technique for predicting foF2. They are also applied, for the first time, to the problem of determining the best predictors of foF2. This quantity depends upon day number, level of solar activity and level of magnetic activity. The optimum averaging lengths of the solar activity index and the magnetic activity index were determined by appling NNs, using the criterion that the best indices are those that give the lowest rms error between the measured and predicted foF2. The optimum index for solar activity was found to be a 2-month running mean value of the daily sunspot number and for magnetic activity a 2-day averaged A index was found to be optimum. In addition, it was found that the response of foF2 to magnetic activity changes is highly non-linear and seasonally dependent. Using these indices as inputs, the NN trained successfully to predict foF2 with an rms error of 0.946 MHz on the daily testing values. Comparison with the IRI showed an improvement of 40% on the rms error. It is also shown that the NN will predict the noon value of foF2 to the same level of accuracy for unseen data of the same type.
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- Date Issued: 1997
A phenomenological investigation into educational leaders' perceptions of themselves, their followers, and their organisational contexts
- Authors: Van der Mescht, Hennie
- Date: 1997
- Subjects: Educational leadership -- Psychological aspects
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1697 , http://hdl.handle.net/10962/d1003580
- Description: Leadership is a richly researched ana widely covered topic, attracting the attention of virtually every discipline within the human sciences. Research which focuses on leadership within an educational context is, however, a relatively recent development. Most of the leadership research conducted in this century has been driven by the needs of industry. Consequently, leadership theories have tended to emphasise the instrumentality, measurability and effectiveness of leadership. Leadership models, intent on being prescriptive and 'learnable', have been inclined to oversimplify the complexity of the leadership phenomenon. Another factor which accounts for these features is the research approach adopted by researchers, which has largely been positivistic. This study is an attempt to investigate the underlying dynamics of educational leadership. It is an in-depth study of five educational leaders' perceptions of themselves as leaders, of the people with whom they interact, and of the organisations within which they work. The study is conducted along the lines suggested by phenomenology, a highly qualitative, anti-positivistic research approach, which encourages the researcher to set aside pre-conceived notions of the phenomenon, and to describe what is found exactly as it presents itself. My findings have highlighted a wide and richly varied range of psychological, emotional and cultural factors which seem to play significant roles in how leaders perceive themselves, others and their environments. Most of these factors have been either entirely ignored or very scantily covered in mainstream leadership literature. Educational leadership emerges as a complex, virtually undefinable phenomenon; new and challenging research approaches and methods have the potential for increasing our understanding of how leaders lead, which in turn will have implications for leadership education and selection.
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- Date Issued: 1997
A predictive biogeography of selected alien plant invaders in South Africa
- Authors: Youthed, Jennifer Gay
- Date: 1997
- Subjects: Alien plants -- South Africa , Biogeography -- South Africa , Acacia -- South Africa , Acacia mearnsii -- South Africa , Opuntia ficus-indica -- South Africa , Solanum -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4846 , http://hdl.handle.net/10962/d1005522 , Alien plants -- South Africa , Biogeography -- South Africa , Acacia -- South Africa , Acacia mearnsii -- South Africa , Opuntia ficus-indica -- South Africa , Solanum -- South Africa
- Description: Five techniques were used to predict the potential biogeography of the four alien plant species, Acacia longifolia, Acacia mearnsii, Opuntia ficus-indica and Solanum sisymbrifolium. Prediction was based on five environmental factors, median annual rainfall, co-efficient of variation for rainfall, mean monthly maximum temperature for January, mean monthly minimum temperature for July and elevation. A geographical information system was used to manage the data and produce the predictive maps. The models were constructed with presence and absence data and then validated by means of an independent data set and chisquared tests. Of the five models used, three (the range, principal components analysis and discriminant function analysis) were linear while the other two (artificial neural networks and fuzzy logic) were non-linear. The two non-linear techniques were chosen as a plant's response to its environment is commonly assumed to be non-linear. However, these two techniques did not offer significant advantages over the linear methods. The principal components analysis was particularly useful in ascertaining the variables that were important in determining the distribution of each species. Artifacts on the predictive maps were also proved useful for this purpose. The techniques that produced the most statistically accurate validation results were the artificial neural networks (77% correct median prediction rate) and the discriminant function analysis (71% correct median prediction rate) while the techniques that performed the worst were the range and the fuzzy classification. The artificial neural network, discriminant function analysis and principal component analysis techniques all show great potential as predictive distribution models.
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- Date Issued: 1997
A quantitative survey of knowledge, attitudes and behaviour, related to AIDS/HIV, among Zulu speaking standard eight high school students
- Authors: Harvey, Brian
- Date: 1997
- Subjects: AIDS (Disease) -- South Africa -- KwaZulu-Natal , AIDS (Disease) -- Social aspects -- South Africa -- KwaZulu-Natal , AIDS (Disease) in adolescence -- South Africa -- KwaZulu-Natal -- Attitudes
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2987 , http://hdl.handle.net/10962/d1002496 , AIDS (Disease) -- South Africa -- KwaZulu-Natal , AIDS (Disease) -- Social aspects -- South Africa -- KwaZulu-Natal , AIDS (Disease) in adolescence -- South Africa -- KwaZulu-Natal -- Attitudes
- Description: AIDS is a serious South African health problem, with HIV infection in KwaZulu-Natal being at the local epidemic's forefront. Adolescents in this province are at additional risk because of their lifestyles. Information on existing risky behaviour and its psychosocial concomitants can provide an important base for educational interventions aimed at reducing further transmission. This study aims to provide baseline information on knowledge, attitudes and reported behaviour, relating to HIV/AIDS, among adolescents in KwaZulu-Natal. A survey, using an anonymous, self-administered questionnaire with closed-ended questions to collect data, was conducted among standard eight Zulu-speaking students (N = 1511) in five parts of the province. The theoretical framework that informed data collection was drawn from the Health Belief Model and Bandura's Social Cognitive Theory. The data generated were first analysed descriptively, providing percentages for responses to individual items. Secondly, cross-tabulations were calculated for relevant items using three independent biographical variables, namely: Locality (rural/peri-urban), gender and students' reports of sexual activity. The results showed inadequate knowledge concerning HIV/AIDS to provide a foundation for developing healthier attitudes. Although most students acknowledged the disease's severity, few reported feeling personally susceptible, denying the immediacy of the threat. Additionally, cues to action and the perceived benefits of adopting preventive behaviours were not influential. Barriers preventing condom use were not primarily logistical, with personal concerns being the main barriers to change. Furthermore, perceived self-efficacy in preventive behaviours was low. Recommendations regarding areas for future research, as well as considerations which will enhance the effectiveness of risk reducing interventions among similar populations, are provided.
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- Date Issued: 1997
A reconstruction of the history of land degradation in relation to land use change and land tenure in Peddie district, former Ciskei
- Authors: Kakembo, Vincent
- Date: 1997
- Subjects: Land use -- South Africa -- Eastern Cape , Land degradation -- South Africa -- Eastern Cape , Soil erosion -- South Africa -- Eastern Cape , Land tenure -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4847 , http://hdl.handle.net/10962/d1005523 , Land use -- South Africa -- Eastern Cape , Land degradation -- South Africa -- Eastern Cape , Soil erosion -- South Africa -- Eastern Cape , Land tenure -- South Africa -- Eastern Cape
- Description: A history of land degradation is reconstructed in a part of the dividing ridge between the Great Fish and Keiskamma rivers, in Peddie District, former Ciskei. The study entails a comparative investigation of the progressive changes in land use, vegetation and soil erosion in three tenure units, namely: former commercial farms, traditional and betterment villages. Analysis of the sequential aerial photography of the area for 1938,1954, 1965, 1975 and 1988 is employed. This is backed by groundtruthing exercises. Data thus obtained are quantified, and linkages between degradation, anthropogenic and physical factors are derived using PC ARC/INFO GIS. Differences in land tenure systems emerge as the main controlling factor to variations in land degradation. Confinement of vegetation diminution and erosion to traditional and betterment villages is observed at all dates. Scantily vegetated surfaces and riparian vegetation removal are a characteristic feature of both areas throughout the study period. 'Betterment,' introduced in the early 1960s to curb land degradation is, instead observed to exacerbate it, particularly soil erosion. Trends in land use change are characterised by the abandonment of cultivated land, which is noted to coincide with a sharp rise in population. Erosion intensification into severe forms particularly between 1965 and 1975, coincident with a period of extreme rainfall events, emerges as the most significant degradation trend. A close spatial correlation between abandoned cultivated land and intricate gullies is identified. So is the case between grazing land and severe sheet erosion. Within the grazing lands, an examination of erosion and categories of vegetated surfaces reveals that erosion occurs predominantly on the scanty vegetation category. Such erosion-vegetation interaction largely explains the non-recovery of the scanty vegetation category, even during periods of intense rainfall. Extensive channel degradation is evident along stream courses with scanty riparian vegetation. Physical factors are noted to have a significant bearing on erosion. The high prevalence of erosion on the Ecca group of rocks confirms its erosion-prone nature. Pockets of colluvium and alluvium accumulation in the steep bottomlands are identified as the sites of the most severe gully erosion. Field surveys at some of the sites indicate that a dolerite sill through the area forms a boundary of colluvium accumulation and the upslope limit to gully incision. That these sites are recognised as formerly cultivated land, portrays the interaction between physical and anthropogenic variables with regard to inducing degradation in the area.
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- Date Issued: 1997
A theology of spiritual direction for the Presbyterian Church of Southern Africa
- Authors: Snyman, Kevin
- Date: 1997
- Subjects: Spiritual direction , Presbyterian Church of Southern Africa
- Language: English
- Type: Thesis , Masters , MTh
- Identifier: vital:1301 , http://hdl.handle.net/10962/d1016260
- Description: This essay is written in response to a lacuna that appears to exist within the Presbyterian Church of Southern Africa with regard to the ancient and highly regarded ministry of spiritual direction. My primary assertion is that, in the light of what might be perceived of as a crisis of relevance in Presbyterian life and spiritual practice, spiritual direction offers one particular way of fostering an exciting and existentially relevant spirituality for the denomination. Through the hoped-for renewal brought about by direction, Presbyterians may well have something to say to a South Africa racked not only with violence and poverty, but also bored by an increasingly irrelevant Christianity. The essay traces that history of spiritual direction most apposite to Presbyterianism in South Africa. This includes an overview of aspects of the Celtic and African spiritual traditions with a view to finding any correspondence that would help to narrow the distance between the spirituality of its black and white members. It then asks questions about the character and tasks of directors. Highlighted is the task of fostering an awareness of God that is not purely ''heavenly minded", but is able to speak into the real issues facing Presbyterians today. The essay goes on to explore the relationship that should exist between director and directee, focussing for a moment on the direction necessary in the directee's prayer life. The essay comes full circle as it considers the implications of introducing direction more widely in this largely "directionless" denomination. As a microcosm of the country, divergent cultures are as much a reality in the P.C.S.A. as in the rest of South Africa. So respect for uniqueness and the practice of interpathy are encouraged as part of the familiarisation process. Throughout the essay, I attempt to show that spiritual direction is a means of allowing the directee to more clearly discern the voice of the Spirit, who constantly encourages the transcendence of self - viz. the breaking of and dying to old perceptions, habits and beliefs so that s/he might more fully enter into the mystery that one usually refers to as God.
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- Date Issued: 1997
An evaluation of small scale open cast mining of UG2 in the Bushveld complex
- Authors: Mooney, David G
- Date: 1997
- Subjects: Platinum mines and mining -- South Africa , Strip mining -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4943 , http://hdl.handle.net/10962/d1005555 , Platinum mines and mining -- South Africa , Strip mining -- South Africa
- Description: The current weak state of the platinum market, as well as the large inventory of platinum group metals held by Russia, necessitates that the South African platinum mining industry must carefully evaluate the benefits and disadvantage of small-scale mining of shallow, open castable ore resources. Until the late 1980's, these resources were ignored due to the metallurgical complexities of treating oxidized ore, as well as the mind set that existed within the South African mining industry which militated against open cast mining in the Bushveld. During the latter part of the 1980's and early 1990's, advances in the metallurgical treatment of oxidized ore, specifically the UG2, as well as operational problems, created the impetus to begin the exploitation of these resources. Small-scale open cast mining has become viable due to the development of suitable mining methods that facilitate mining practices acceptable to the Department of Mineral and Energy Affairs, in terms of environmental legislation. Metallurgical advances and growing experience, especially with respect to the UG2, enables reasonable platinum group metals recovery from oxidized ore. The problems experienced in doing this can, and are being overcome. With growing public awareness of environmental issues, particularly related to the mining industry, the requirement to ensure that the small-scale open cast mine site is well managed is paramount. A methodology for the evaluation is presented along with a case study of a small-scale UG2 open cast pit. Evidence is presented that shows that these small-scale open cast mining operations are extremely profitable and require minimal capital expenditure. However, caution is advised when evaluating Merensky Reef open cast operations because of the problems that they present.
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- Date Issued: 1997
An examination of the factors underlying decision-making about selection and presentation of photographs of political conflict in South African newspapers
- Authors: O'Dowd, Catherine Frances
- Date: 1997
- Subjects: Photojournalism , Photojournalism -- South Africa , Photojournalists -- South Africa , South Africa -- Politics and government -- 1989-1994
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3478 , http://hdl.handle.net/10962/d1002933 , Photojournalism , Photojournalism -- South Africa , Photojournalists -- South Africa , South Africa -- Politics and government -- 1989-1994
- Description: What newspaper readers see of an event is detennined by what photographs are seley ted and how they are presented. This thesis attempts to deconstruct the decision-making process around selection and presentation of photographs, with the aim of detennining what factors are taken into account in that process. It is based on the hypothesis that there must be a number of factors involved in decisions about news photographs, although these factors may not necessarily be consciously acknowledged in the decision-making process. The study involves a comparison of how five case studies of incidents of political violence, which occurred between 1990 and 1994 in South Africa, were used'in lrinewspapers. The focus on images of political violence is based on the assumption that politically and visually controversial images will give rise to situations in which gatekeepers will be caned upon to question their decisions. The research is based on qualitative research interviews with the decision-makers involved in the case studies. The analysis of the decision-making procedures is based on the theory of gatekeeping. The interviews are analysed in terms of Lewin's theory offqrces, which suggests that, depending on the context, some factors will manifest themselves as positive forces working in favour of the photograph being selected or well presented, while others will take the form of negative forces. The analysis sets out to determine what factors were taken into account in the decision::making process, what detennined their relative degrees of importance and how those relative degrees of importance determined the final outcome. Following an introduction to the practical case study research, dealing with general issues such as picture policy in newspapers and decision-making procedures, each case study is dealt with in turn. After an outline of the context in which the event occurred, the kinds of pictures that were available to the newspapers are described. Then the decisions taken about which to choose and how to use them are analysed in terms of dominant themes. These are themes such as newsworthiness, gruesomeness of content and concern abo!Jt what other media were using. The analysis examines the way the news context and the decision-making context determine the relative importance of the various factors present. Finally the study looks at the conclusions that can be drawn from the five case studies. The conclusion supports the initial hypothesis in finding that these decisions can be shown to have their basis in a fairly limited set of factors. The different results, from study to study and from newspaper to newspaper within a study, are determined by the changing news context and the decisi~n-making context.
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- Date Issued: 1997
An investigation into patterns of interaction in small teaching groups at Rhodes University, with particular emphasis on the effect of gender, mother-tongue and educational background
- Authors: Hunt, Sally Ann
- Date: 1997
- Subjects: Tutors and tutoring , Multicultural education--South Africa , Group work in education , Small groups--Study and teaching (Higher)
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2350 , http://hdl.handle.net/10962/d1002632 , Tutors and tutoring , Multicultural education--South Africa , Group work in education , Small groups--Study and teaching (Higher)
- Description: The assumption underlying this study is that knowledge is constructed through interaction. Small teaching groups, or tutorials, are often regarded as a particularly effective context for learning in the setting of tertiary education in that they provide an environment for free interaction between students, and thus facilitate active learning. Factors which systematically affect the degree of participation of the individual in tutorIals -directly affect the learning experience of that individual and raise questions about the equality achieved in tutorials, in terms of opportunities for learning. This study focuses on one such type of factor: culturally acquired norms of interaction. The individual is seen as a composite of cultural identities, utilising norms acquired through socialisation and experience in appropriate contexts. Previous research has demonstrated that gendered norms of interaction and those associated with the individual's mother-tongue are particularly salient. In the educational context, norms acquired through previous experience of education are likely to be carried over to the new setting of the university. Thus these factors form the focus of this study. One flrst-year tutorial from each of five departments in the Faculties of Arts and Social Science at Rhodes University, Grahamstown, was video-recorded and the data thus obtained was analyzed for patterns of interaction in terms of gender, mother-tongue and educational background. A model of utterance types was developed to provide a structured description of the patterns found in the tutorials. Interviews and video-sessions with a sample of the tutorial members were conducted, which add a qualitative dimension to the investigation and allow for triangulation. The recorded tutorials and interviews reveal a marked awareness amongst students of the composition of tutorial groups in terms of gender and ethnicity and this composition appears to affect the relative participation of students, in that members of numerically dominant groups are more willing to participate. This is particularly clear in the case of female students. With regard to second-language (L2) speakers of English, a number of factors are highlighted which tend to decrease participation. Apart from problems with English as the medium of instruction, these students tend to be reluctant to participate due to cultural norms, according to which students, as subordinates, should not take the initiative in interaction, in order to show appropriate respect. Patterns of interaction by L2 students from racially integrated schools, however, do not conform to this set of norms as strongly. It is argued that sensitivity is required to address this situation and a number of options are presented.
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- Date Issued: 1997
An investigation into the effects of inorganic toxins and tryptophan metabolites on the forebrain cholinergic system and the pineal gland of the rat
- Authors: Mahabeer, Rajeshree
- Date: 1997
- Subjects: Toxins -- Physiological effect , Metabolites -- Physiological effect , Pineal gland , Brain -- Physiological aspects
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4018 , http://hdl.handle.net/10962/d1004078 , Toxins -- Physiological effect , Metabolites -- Physiological effect , Pineal gland , Brain -- Physiological aspects
- Description: As soon as the building of the body is completed, the ageing process begins. In the natural course of events, the functioning of some organ systems finally ebbs below the threshold necessary to maintain the body, resulting in death. This occurrence is relatively rare, because diseases superimpose themselves upon the ageing process, bringing premature death resulting from pathological causes. This study focused on the cholinergic system of the rat forebrain. The cholinergic neurons in the brain are said to be involved in memory and learning, and a decrease in the activity of its enzymes has been reported in certain diseases, such as Alzheimer's disease. In the present study, the in vitro effects on the cholinergic system, of aluminium and mercury and tryptophan metabolites, kynurenic acid and quinolinic acid, are determined. Aluminium has been considered as a possible factor in Alzheimer's disease. Mercury in high concentrations is toxic, and its use in amalgam for dental treatment is under consideration with regard to its possible role in promoting neurological disease. The tryptophan metabolites increase in the brain with age and may have a role in pathological diseases. Quinolinic acid, when administered in toxic concentrations produces a possible model for Huntington's disease. This study investigated the effects of the above mentioned toxins on: (1) The synthesis of acetylcholine by choline acetyltransferase; (2) The specific binding of acetylcholine muscarinic receptors; (3) The degradation of acetylcholine by acetyl cholinesterase, Choline acetyltransferase activity did not change in the presence of aluminium chloride, kynurenic acid and quinolinic acid from 1 nM to 1 mM. Mercuric chloride had no significant effect on the enzymes activity from a concentration of 1 nM- 1 pM. At 10 pM there was a significant decrease in cholineacetyltransferase activity (P < 0.001). Enzyme activity continued to decrease at 100 pM (P < 0.0002). At 1 mM, enzyme activity was virtually non existent (P < 0.0001). Acetyl cholinesterase activity was not affected by aluminium chloride, kynurenic acid and quinolinic acid. Mercuric chloride from 1 pM - 1 mM significantly reduced the enzyme activity (P < 0.05). The binding of the antagonist, [³H] quinuclidinyl benzilate (QNB), to acetylcholine muscarinic receptors, revealed that aluminium chloride did not affect the binding of the antagonist, in the concentration range of 1 nM - 100 pM, to the receptors. At 1 mM, aluminium chloride appears to increase the sensitivity of the receptors for the ligand (P < 0.01). Mercuric chloride also does not appear to have any significant effect on receptor binding in this range. However, at 1 mM there appears to be a very significant decrease in receptor binding (P < 0.01). This decrease may be attributed to the interaction of mercury with the sulfhydryl groups in muscarinic receptors. Kynurenic acid had no effect on the receptor binding. Quinolinic acid, in the concentration range from 10 nM - 1 mM increased the binding ofthe receptor to [3Hi QNB significantly (P < 0.001). The study also investigated the effect of the tryptophan metabolites of the kynurenine pathway on pineal indole metabolism. The kynurenine pathway is a major route of tryptophan metabolism in the pineal gland, along with indole metabolism. Investigations showed that kynurenic acid produced a decrease in N-acetylserotonin concentrations ( P < 0.001) and melatonin concentrations (P < 0.003). Further experiments using quinolinic acid produced a similar decrease in N-acetylserotonin (P < 0.001) and melatonin (P < 0.015). A decrease was also noted in the level of 5-methoxytryptophol (P < 0.0005). These findings suggest that aluminium chloride, kynurenic acid and quinolinic acid have no possible role in the decrease of activity of cholinergic enzymes which is observered in diseases such as Alzheimer's disease. The results regarding the effect of mercury chloride on the cholinergic system suggest that low exposure to the toxin will not adversely effect the enzymes. The decrease in N-acetylserotonin and melatonin concentrations reported here, may be a result of kynurenic acid and quinolinic acid having an inhibitory effect on the enzyme, serotonin Nacetyltransferase, which is responsible for the conversion of serotonin to N-acety/serotonin.
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- Date Issued: 1997
An investigation into the enlightenment and aspects of Spanish life which may have influenced Los Caprichos (1797-1799) of Francisco de Goya (1746-1828)
- Authors: Ralls, Warren John
- Date: 1997
- Subjects: Goya, Francisco, 1746-1828 -- Criticism and interpretation Goya, Francisco, 1746-1828. Caprichos
- Language: English
- Type: Thesis , Masters , MFA
- Identifier: vital:2421 , http://hdl.handle.net/10962/d1002217
- Description: The aim of this mini-thesis was to investigate if the Spanish artist Francisco Jose de Goya y Lucientes (1746-1828) was aware of the progress that enlightened thought brought to Spain during the late eighteenth-century, and to see whether this had any effect on his series Los Caprichos (1797-1799). According to some contemporary historians, such as Dowling (1985, p. 347), the " ... specific subject-matter of the Caprichos came directly from the ideology of the Spanish Enlightenment. " The contemporary historian Jeremy Black (1990, p. 208) described the Enlightenment as a " ... tendency towards critical enquiry and the application of reason." Enlightened thinkers were primarily critics who used reason as a goal and a method to create a better society. Reason was believed to be a characteristic trait of the human species, human development and social organisation. The Enlightenment is not a purely seventeenth and eighteenth century phenomenon, but originated in the ideas of the classical civilizations and also the humanism of the Middle Ages and Renaissance in Europe. Many intellectuals were responsible for this new direction of thinking. The ideas of these scientists and philosophers are discussed in some detail, especially those beliefs which are clearly seen in the subject-matter of Los Caprichos. In addition, consideration is given to the possible effects of some of the historical events on the life and work of Goya, for example, the French Revolution (1789) and the Reign of Terror (1793-1794) which followed the Revolution. In order to understand the background of the environment into which Goya was born and in which he developed, research was done on Spanish life and the monarchs of the eighteenth century. Specific attention is given to two Spanish kings from the House of Bourbon: Charles 3, who began numerous enlightened reforms in Spain and reigned around the time of Goya's early artistic and social development, and Charles 4 who did not continue the reforming policies of his father and ruled Spain when the Caprichos were produced. The extent to which the Enlightenment spread to Spain is investigated, especially during the period in which Goya lived. Notable progressive thinkers of this European country are discussed, and special attention is given to those open-minded people whom Goya met. There appears to be proof that Goya may have been inspired by numerous of these learned Spaniards, and where this has motivated the Caprichos, special mention is made. The general census of the twentieth century, however, seems to be that Goya was not a towering intellectual thinker, but he was most certainly not an illiterate, unintelligent person either. The themes of Los Caprichos strongly suggest that he was influenced by enlightened individuals many of whom were his friends, such as the wealthy businessman and art-collector Sebastian Martinez (17 ?-1800) (with whom Goya stayed during a serious illness in 1792-1793). The letters written by Goya to his childhood friend Martin Zapater (1746-18 ?) and selected prints from the Caprichos provide sufficient proof to indicate that enlightened thought inspired the work of Goya. It must be recognised, however, that there were other events that could have been influential such as: his appointment as Painter to the King in 1786, which provided Goya with a regular salary and released him from the demands of patrons, giving his imagination free reign; the illness that he suffered from 1792 until 1793, which could have caused Goya to view his life in perspective and could have given him the courage to criticise society. On a smaller scale, the possible love affair that Goya had with the Duchess of Alba, which turned sour, was possibly a blow to his self esteem. This is a subject which is seen in a few of the prints from Los Caprichos. The research gathered for this mini-thesis is from the ex post facto source-material available through Rhodes University library, and any other attainable published data connected to Goya. This information consists of secondary sources which include copies of manuscripts dating from the time of Goya as well as first-hand observations of Goya's art.
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- Date Issued: 1997
An investigation into the visual literacy skills of Black primary-school children from an informal settlement in Cape Town, with particular reference to visual imagery in educational textbooks
- Authors: Griffiths, Corona Gracelyn
- Date: 1997
- Subjects: Textbooks Illustrations , Visual literacy , Literacy -- South Africa , Visual literacy -- South Africa , Visual communication , Black people -- Education (Primary) -- South Africa , School children -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2403 , http://hdl.handle.net/10962/d1002199 , Textbooks Illustrations , Visual literacy , Literacy -- South Africa , Visual literacy -- South Africa , Visual communication , Black people -- Education (Primary) -- South Africa , School children -- South Africa
- Description: This thesis provides evidence that learning difficulties some. black primary-schoolchildren may experience with certain textbooks, can be attributed, in part, to the visual text (imagery). These difficulties were established by eliciting responses from educationally dlscfdvantaged urban black primary learners to selected examples of visual texts using the Research Interview method. To further establish if these difficulties were attributable either to poorly executed/unrecognizable visual text, or to low levels of learned educational visual literacy skills - white primary-school children were also interviewed - as it was anticipated that they would be familiar with Western pictorial material due to their consistent exposure to books from an early age. The difficulties experienced by the black interviewees were attributed mainly to their level of learned pictorial perceptual skills and to a lesser extent to poorly/inadequately illustrated visual texts. It was found from interviews with the developers of visual texts - publishing personnel and illustrators - that the former were not entirely certain e.xactly which aspects of visual text were difficult for black primary learners to comprehend, while the latter were generaUy very uncertain. The procedure for visual text development by the developers (including textbook authors), was found to be problematic due to the lack of synthesis and consultative decision making in the process- between these persons. The limited time allocated to illustrators for producing visual text, as well as their professional isolation, were found to be factors which can give rise to ineffective and inadequate visual texts. Most publishers and authors, if they trial (field-test) materials, generally do not trial the visual text. The visual text is usually decided upon ultimately by the poblishers and produced after trialling and/or consultants have examined the written text. Consequently incongruent meanings and inconsistencies can result between written and visual text, which can affect the learning effectiveness of the composite text. Trialling (field-testing) of visual and written text together, was recommended to identify and address any difficulties experienced by learners prior to final publication of the textbook. Recommendations were provided for textbook selection committees, authors, teachers, publishers and illustrators.
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- Date Issued: 1997
An investigation of nondeterminism in functional programming languages
- Authors: Graham, Gwyneth Clare
- Date: 1997
- Subjects: Functional programming languages
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4658 , http://hdl.handle.net/10962/d1006658 , Functional programming languages
- Description: This thesis investigates nondeterminism in functional programming languages. To establish a precise understanding of nondeterministic language properties, Sondergaard and Sestoft's analysis and definitions of functional language properties are adopted as are the characterizations of weak and strong nondeterminism. This groundwork is followed by a denotational semantic description of a nondeterministic language (suggested by Sondergaard and Sestoft). In this manner, a precise characterization of the effects of strong nondeterminism is developed. Methods used to hide nondeterminism to in order to overcome or sidestep the problem of strong nondeterminism in pure functional languages are defined. These different techniques ensure that functional languages remain pure but also include some of the advantages of nondeterminism. Lastly, this discussion of nondeterminism is applied to the area of functional parallel language implementation to indicate that the related problem and the possible solutions are not purely academic. This application gives rise to an interesting discussion on optimization of list parallelism. This technique relies on the ability to decide when a bag may be used instead of a list.
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- Date Issued: 1997
An overview of the early-proterozoic, auriferous Black Reef placer in the Transvaal Basin
- Authors: De Bever, Johannes Nicolaas
- Date: 1997
- Subjects: Geology, Economic -- South Africa , Placer deposits -- South Africa , Prospecting -- Research -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4984 , http://hdl.handle.net/10962/d1005596 , Geology, Economic -- South Africa , Placer deposits -- South Africa , Prospecting -- Research -- South Africa
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- Date Issued: 1997