Nutrient supplementation and secondary metaolites in melanoma cells
- Authors: Stoll, Karin Elisabeth
- Date: 1994
- Subjects: Vitamin C -- Therapeutic use Cancer -- Research
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4049 , http://hdl.handle.net/10962/d1004110
- Description: Considerable interest exists with regard to the putative therapeutic role of ascorbic acid in various conditions. A condition which has received much attention is cancer, as it is reported that ascorbic acid may be a prophylactic against cancer development. However, the actual involvement of ascorbic acid, an oxidizing/reducing agent, in the development and progression of tumours is presently a subject of much speculation. This study initially addressed the effect of ascorbic acid supplementation over a nutritional concentration range (0 - 100 μg/ml) on the in vitro growth of non-malignant LLCMK and malignant B16 cells. Ascorbic acid supplementation of these two cell types resulted in an overall decrease in the growth of both types of cells. The actual inhibitory mechanism of ascorbic acid on cell growth was not clear. Further study attempted to define and explain a mechanism responsible for this effect. Ascorbic acid has a role in the maintenance of tissue integrity and host defences, thus providing a rational basis for examining its relationship to cancer. Ascorbic acid is lcnown to be essential for the structural integrity of the intercellular matrix of the cells, the latter being a complex aqueous gel containing, amongst other compounds, fats and prostaglandins. Fats and prostaglandins have diverse effects on. membrane stability, enzyme activity and secondary messengers within cells. Hence, this study investigated the effect of ascorbic acid supplementation on certain enzymes and secondary metabolites within the cells, which had the potential to be involved in the control of cell growth. Throughout this study, emphasis was placed on the Bl6 melanoma cells as ascorbic acid supplementation did not significantly affect levels of secondary metabolites within the non-malignant LLCMK cells. Ascorbic acid supplementation of the B16 cells resulted in significant increases in adenylate cyclase activity and cyclic adenosine monophosphate levels, witb a significant decrease in Bl6 cell growth in that particular experiment. As cyclic adenosine monophosphate has a regulatory role in the cell cycle, this study suggested that the inhibitory effect of ascorbic acid supplementation on cell growth was mediated tbrough a final effect provided by the second messenger, cyclic adenosine monophosphate. However, clarification of tbe mechanism of tbe effect of ascorbic acid on adenylate cyclase activity was required. Hence, a further study investigated prostaglandin E₂ levels, as tbese affect adenylate cyclase activity. Prostaglandin E₂ levels were also found to be inversely related to Bl6 cell growth with ascorbic acid supplementation. It thus appeared tbat adenylate cyclase activity was dependent on prostaglandin E₂ levels in the B16 cells, and further study showed that tbis was indeed the case. Here, higher levels of prostaglandin E₂ supplementation of the Bl6 cells inhibited cell growth significantly and also significantly increased adenylate cyclase activity. Arachidonic acid is the precursor of prostaglandin E₂. In the presence of ascorbic acid supplementation, the percentage arachidonic acid composition of the Bl6 cells was inversely correlated with cell growth. Hence, prostaglandin E₂ levels in ascorbic acid supplemented B16 cells appeared dependent on tbe amount of precursor present. This was confirmed when Bl6 cells were supplemented with arachidonic acid. The latter had an inhibitory effect on Bl6 cell growth and also stimulated prostaglandin E₂ production. The cause of tbe inverse relationship between B16 cell growth and arachidonic acid composition with ascorbic acid supplementation was furtber investigated and found to be dependent on tbe uptake of arachidonic acid and other essential fatty acids from tbe medium. The enzymes phospholipase A₂ delta-5 and delta-6-desaturase, and elongase which could influence arachidonic acid levels were not affected to any extent by ascorbic acid supplementation and therefore did not influence the inverse relationship between B16 cell growth and arachidonic acid. Hence, it can be concluded that the effect of ascorbic acid supplementation on the BI6 cells is mediated, in part at least, by cyclic adenosine monophosphate. However, this is not the result of a direct effect of ascorbic acid supplementation. The initial effect of ascorbic acid supplementation concerns fatty acid - in particular arachidonic acid - uptake from the medium, with subsequent cascade effects On secondary metabolites, ultimately affecting the cellular levels of cyclic adenosine monophosphate.
- Full Text:
- Date Issued: 1994
- Authors: Stoll, Karin Elisabeth
- Date: 1994
- Subjects: Vitamin C -- Therapeutic use Cancer -- Research
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4049 , http://hdl.handle.net/10962/d1004110
- Description: Considerable interest exists with regard to the putative therapeutic role of ascorbic acid in various conditions. A condition which has received much attention is cancer, as it is reported that ascorbic acid may be a prophylactic against cancer development. However, the actual involvement of ascorbic acid, an oxidizing/reducing agent, in the development and progression of tumours is presently a subject of much speculation. This study initially addressed the effect of ascorbic acid supplementation over a nutritional concentration range (0 - 100 μg/ml) on the in vitro growth of non-malignant LLCMK and malignant B16 cells. Ascorbic acid supplementation of these two cell types resulted in an overall decrease in the growth of both types of cells. The actual inhibitory mechanism of ascorbic acid on cell growth was not clear. Further study attempted to define and explain a mechanism responsible for this effect. Ascorbic acid has a role in the maintenance of tissue integrity and host defences, thus providing a rational basis for examining its relationship to cancer. Ascorbic acid is lcnown to be essential for the structural integrity of the intercellular matrix of the cells, the latter being a complex aqueous gel containing, amongst other compounds, fats and prostaglandins. Fats and prostaglandins have diverse effects on. membrane stability, enzyme activity and secondary messengers within cells. Hence, this study investigated the effect of ascorbic acid supplementation on certain enzymes and secondary metabolites within the cells, which had the potential to be involved in the control of cell growth. Throughout this study, emphasis was placed on the Bl6 melanoma cells as ascorbic acid supplementation did not significantly affect levels of secondary metabolites within the non-malignant LLCMK cells. Ascorbic acid supplementation of the B16 cells resulted in significant increases in adenylate cyclase activity and cyclic adenosine monophosphate levels, witb a significant decrease in Bl6 cell growth in that particular experiment. As cyclic adenosine monophosphate has a regulatory role in the cell cycle, this study suggested that the inhibitory effect of ascorbic acid supplementation on cell growth was mediated tbrough a final effect provided by the second messenger, cyclic adenosine monophosphate. However, clarification of tbe mechanism of tbe effect of ascorbic acid on adenylate cyclase activity was required. Hence, a further study investigated prostaglandin E₂ levels, as tbese affect adenylate cyclase activity. Prostaglandin E₂ levels were also found to be inversely related to Bl6 cell growth with ascorbic acid supplementation. It thus appeared tbat adenylate cyclase activity was dependent on prostaglandin E₂ levels in the B16 cells, and further study showed that tbis was indeed the case. Here, higher levels of prostaglandin E₂ supplementation of the Bl6 cells inhibited cell growth significantly and also significantly increased adenylate cyclase activity. Arachidonic acid is the precursor of prostaglandin E₂. In the presence of ascorbic acid supplementation, the percentage arachidonic acid composition of the Bl6 cells was inversely correlated with cell growth. Hence, prostaglandin E₂ levels in ascorbic acid supplemented B16 cells appeared dependent on tbe amount of precursor present. This was confirmed when Bl6 cells were supplemented with arachidonic acid. The latter had an inhibitory effect on Bl6 cell growth and also stimulated prostaglandin E₂ production. The cause of tbe inverse relationship between B16 cell growth and arachidonic acid composition with ascorbic acid supplementation was furtber investigated and found to be dependent on tbe uptake of arachidonic acid and other essential fatty acids from tbe medium. The enzymes phospholipase A₂ delta-5 and delta-6-desaturase, and elongase which could influence arachidonic acid levels were not affected to any extent by ascorbic acid supplementation and therefore did not influence the inverse relationship between B16 cell growth and arachidonic acid. Hence, it can be concluded that the effect of ascorbic acid supplementation on the BI6 cells is mediated, in part at least, by cyclic adenosine monophosphate. However, this is not the result of a direct effect of ascorbic acid supplementation. The initial effect of ascorbic acid supplementation concerns fatty acid - in particular arachidonic acid - uptake from the medium, with subsequent cascade effects On secondary metabolites, ultimately affecting the cellular levels of cyclic adenosine monophosphate.
- Full Text:
- Date Issued: 1994
Photoreduction of tin (IV) phthalocyanines
- Authors: Nyokong, Tebello
- Date: 1994
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/293413 , vital:57083 , xlink:href="https://doi.org/10.1016/S0277-5387(00)83491-9"
- Description: Photolysis of Sn(IV)Pc(OH)2 (Pc = phthalocyanine dianion) and Sn(IV)Pc(Cl)2 using a tungsten lamp, and in the presence of SnCl2·2H2O as an electron donor results in the reduction of these complexes of π anion radical species. The reduction shows second order dependence on the concentration of the Sn(IV)Pc complexes and a first order dependence on SnCl2·H2O.
- Full Text:
- Date Issued: 1994
- Authors: Nyokong, Tebello
- Date: 1994
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/293413 , vital:57083 , xlink:href="https://doi.org/10.1016/S0277-5387(00)83491-9"
- Description: Photolysis of Sn(IV)Pc(OH)2 (Pc = phthalocyanine dianion) and Sn(IV)Pc(Cl)2 using a tungsten lamp, and in the presence of SnCl2·2H2O as an electron donor results in the reduction of these complexes of π anion radical species. The reduction shows second order dependence on the concentration of the Sn(IV)Pc complexes and a first order dependence on SnCl2·H2O.
- Full Text:
- Date Issued: 1994
Southern African Journal of Gerontology, volume 3, number 1, April 1994
- Ferreira, Monica (editor), Møller, Valerie (editor), HSRC/UCT Centre for Gerontology
- Authors: Ferreira, Monica (editor) , Møller, Valerie (editor) , HSRC/UCT Centre for Gerontology
- Date: 1994
- Subjects: Gerontology -- South Africa , Older people -- Care -- South Africa
- Language: English
- Type: Text
- Identifier: vital:8068 , http://hdl.handle.net/10962/d1012860
- Description: A typical case, culled from the author's own experience in the Third World, points towards a major crisis in ageing in the near future for many developing countries. Whilst the increase in numbers of elderly, both gross and proportionate, is well-known, it is not so widely realised that the increase in developing countries will far outstrip that in industrialized nations. Although the elderly were historically cared for within the traditional extended family structure, that system is now breaking down before the advance of migration and easy divorce. Many elderly persons are left alone in depopulated communities. Others fail to adapt in the rural-to-urban transition. Most developing countries have no firmly established services for the elderly. However, as awareness of the impending crisis increases, community groups assist the elderly in developing their own initiatives to avoid the local effects of the crisis.
- Full Text:
- Date Issued: 1994
- Authors: Ferreira, Monica (editor) , Møller, Valerie (editor) , HSRC/UCT Centre for Gerontology
- Date: 1994
- Subjects: Gerontology -- South Africa , Older people -- Care -- South Africa
- Language: English
- Type: Text
- Identifier: vital:8068 , http://hdl.handle.net/10962/d1012860
- Description: A typical case, culled from the author's own experience in the Third World, points towards a major crisis in ageing in the near future for many developing countries. Whilst the increase in numbers of elderly, both gross and proportionate, is well-known, it is not so widely realised that the increase in developing countries will far outstrip that in industrialized nations. Although the elderly were historically cared for within the traditional extended family structure, that system is now breaking down before the advance of migration and easy divorce. Many elderly persons are left alone in depopulated communities. Others fail to adapt in the rural-to-urban transition. Most developing countries have no firmly established services for the elderly. However, as awareness of the impending crisis increases, community groups assist the elderly in developing their own initiatives to avoid the local effects of the crisis.
- Full Text:
- Date Issued: 1994
Author, ideology and publisher a symbiotic relationship : Lovedale Missionary Press and early Black writing in South Africa: with specific reference to the critical writings of H.I.E. Dlomo
- Authors: Midgley, Henry Peter
- Date: 1994
- Subjects: Shepherd, Robert H W (Robert Henry Wishart), 1888-1971 Dhlomo, H I E (Herbert I E), 1903-1956 Rhodes University Dissertations African literature Lovedale Institution South African literature -- Black authors -- History and criticism South African literature (English) -- History and criticism Politics and literature -- South Africa -- History -- 20th century Press and politics -- South Africa -- History
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2241 , http://hdl.handle.net/10962/d1002284
- Description: The specific instances of R.H.W. Shepherd and H.I.E. Dhlomo are used in this thesis to investigate some of the many factors that influence the formation of a colonial literature, such as politics, social structures and personal ideals. By isolating the Lovedale Mission Press ~s a "contact zone" - a·place where the cultures of the colonizer and the colonized come into direct contact with each other - it is possible to trace how the interaction between these cultures shaped the writing of a particular African writer, H.I.E. Dhlomo. This is done through an analysis of historical factors that shaped the policy of the Lovedale Mission Press in the twentieth century: the development of liberalism in South Africa, the·role of the missionary in African education, the function ofa liberal magazine such as The South African Outlook and the appointment of an ambitious missionary, R.I.W. Shepherd, to the position of Director of Publications. This necessarily included a study of Shepherd's vision of African literature. On the other hand, this study takes cognisance of the factors that shaped Herbert Dhlomo's vision of literature: the development of African nationalism, the entrenchment of segregation as a politial doctrine, and most importantly, his struggle to have his creative writing published by the Lovedale Press. It is shown how Shepherd's vision of what African literature should entail contrasted with Dhlomo's, and how, as a result, Dhlomo deliberately structured his critical writing as a response to Shepherd's Eurocentric approach to African literature.
- Full Text:
- Date Issued: 1994
- Authors: Midgley, Henry Peter
- Date: 1994
- Subjects: Shepherd, Robert H W (Robert Henry Wishart), 1888-1971 Dhlomo, H I E (Herbert I E), 1903-1956 Rhodes University Dissertations African literature Lovedale Institution South African literature -- Black authors -- History and criticism South African literature (English) -- History and criticism Politics and literature -- South Africa -- History -- 20th century Press and politics -- South Africa -- History
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2241 , http://hdl.handle.net/10962/d1002284
- Description: The specific instances of R.H.W. Shepherd and H.I.E. Dhlomo are used in this thesis to investigate some of the many factors that influence the formation of a colonial literature, such as politics, social structures and personal ideals. By isolating the Lovedale Mission Press ~s a "contact zone" - a·place where the cultures of the colonizer and the colonized come into direct contact with each other - it is possible to trace how the interaction between these cultures shaped the writing of a particular African writer, H.I.E. Dhlomo. This is done through an analysis of historical factors that shaped the policy of the Lovedale Mission Press in the twentieth century: the development of liberalism in South Africa, the·role of the missionary in African education, the function ofa liberal magazine such as The South African Outlook and the appointment of an ambitious missionary, R.I.W. Shepherd, to the position of Director of Publications. This necessarily included a study of Shepherd's vision of African literature. On the other hand, this study takes cognisance of the factors that shaped Herbert Dhlomo's vision of literature: the development of African nationalism, the entrenchment of segregation as a politial doctrine, and most importantly, his struggle to have his creative writing published by the Lovedale Press. It is shown how Shepherd's vision of what African literature should entail contrasted with Dhlomo's, and how, as a result, Dhlomo deliberately structured his critical writing as a response to Shepherd's Eurocentric approach to African literature.
- Full Text:
- Date Issued: 1994
Abdoul Aziz
- Tidiane Gaye (lead vocal), Assane Diop (solo guitar), Niankou Sembene (keyboards), Ousseynou Diop (drums), Moussa Sene, Mor Sourang, Thio Mbaye (percussion), Mada Ba (chorus), Galissa (kora), Mamane Thiam (tama), Studio 2000, Samassa Records
- Authors: Tidiane Gaye (lead vocal) , Assane Diop (solo guitar) , Niankou Sembene (keyboards) , Ousseynou Diop (drums) , Moussa Sene, Mor Sourang, Thio Mbaye (percussion) , Mada Ba (chorus) , Galissa (kora) , Mamane Thiam (tama) , Studio 2000 , Samassa Records
- Date: 1994
- Subjects: Popular music--Africa, West , Africa Senegal Dakar f-sg
- Language: Wolof
- Type: sound recordings , field recordings , sound recording-musical
- Identifier: http://hdl.handle.net/10962/130060 , vital:36371 , International Library of African Music, Rhodes University, Grahamstown, South Africa , SDC37-02
- Description: Popular Senegalese music incorporating pop, funk, Congolese ndombolo, cut-shifted Ivorian or Afro-dance
- Full Text: false
- Date Issued: 1994
- Authors: Tidiane Gaye (lead vocal) , Assane Diop (solo guitar) , Niankou Sembene (keyboards) , Ousseynou Diop (drums) , Moussa Sene, Mor Sourang, Thio Mbaye (percussion) , Mada Ba (chorus) , Galissa (kora) , Mamane Thiam (tama) , Studio 2000 , Samassa Records
- Date: 1994
- Subjects: Popular music--Africa, West , Africa Senegal Dakar f-sg
- Language: Wolof
- Type: sound recordings , field recordings , sound recording-musical
- Identifier: http://hdl.handle.net/10962/130060 , vital:36371 , International Library of African Music, Rhodes University, Grahamstown, South Africa , SDC37-02
- Description: Popular Senegalese music incorporating pop, funk, Congolese ndombolo, cut-shifted Ivorian or Afro-dance
- Full Text: false
- Date Issued: 1994
Systematics and Osteology of the Zoarcidae (Teleostei: Perciformes)
- Authors: Anderson, M Eric
- Date: 1994
- Language: English
- Type: Text
- Identifier: vital:15033 , http://hdl.handle.net/10962/d1019910 , ISSN 0073-4381 , Ichthyological Bulletin of the J.L.B. Smith Institute of Ichthyology; No. 60
- Description: The eelpouts, Zoarcidae, are a group of perciform fishes, most species of which inhabit continental shelves and slopes of boreal seas. There are about 220 valid species of eelpouts; most are rare, deep-sea forms and the systematics and biology of the group has been neglected by most workers. This work is a contribution to the improvement of that state. The anatomy of the Zoarcidae was studied in an attempt to reconstruct phylogeny and establish generic limits. From an analysis of a matrix of 76 characters, the 45 genera recognised here form 4 subfamilies. The Lycozoarcinae contains only the primitive Lycozoarces hubbsi. The others, Zoarcinae, Gymnelinae, and Lycodinae, for the most part, include genera recognised in previous classifications (Gill, 1862, 1864; Andriashev, 1939). The more primitive zoarcids are characterised by having 4-6 suborbital bones arranged in a circular pattern close to the orbit, and “complete” cephalic lateralis pore patterns, except some of the few deep-sea forms. The more derived zoarcids are characterized by having 6-11 suborbital bones arranged in an angled, or “L”-shaped" pattern away from the orbit (except a few which have lost some bones) and the loss of the interorbital pores (except for some reversals in Lycenchelys and Lycodapus). Zoarcids are considered to have originated in the North Pacific Ocean, perhaps as early as the Eocene, when a pre-percoid radiation occurred. The suborder Zoarcoidei (today some 8-9 families) spread across the Pacific rim. Among Zoarcidae, a pre-Miocene radiation took place along the western coasts of the Americas, with areas of endemism forming in the Magellan Province of South America and Antarctica. Subsequent spreading back into northern waters occurred in Melanostigma and Pachycara. , Rhodes University Libraries (Digitisation)
- Full Text:
- Date Issued: 1994
- Authors: Anderson, M Eric
- Date: 1994
- Language: English
- Type: Text
- Identifier: vital:15033 , http://hdl.handle.net/10962/d1019910 , ISSN 0073-4381 , Ichthyological Bulletin of the J.L.B. Smith Institute of Ichthyology; No. 60
- Description: The eelpouts, Zoarcidae, are a group of perciform fishes, most species of which inhabit continental shelves and slopes of boreal seas. There are about 220 valid species of eelpouts; most are rare, deep-sea forms and the systematics and biology of the group has been neglected by most workers. This work is a contribution to the improvement of that state. The anatomy of the Zoarcidae was studied in an attempt to reconstruct phylogeny and establish generic limits. From an analysis of a matrix of 76 characters, the 45 genera recognised here form 4 subfamilies. The Lycozoarcinae contains only the primitive Lycozoarces hubbsi. The others, Zoarcinae, Gymnelinae, and Lycodinae, for the most part, include genera recognised in previous classifications (Gill, 1862, 1864; Andriashev, 1939). The more primitive zoarcids are characterised by having 4-6 suborbital bones arranged in a circular pattern close to the orbit, and “complete” cephalic lateralis pore patterns, except some of the few deep-sea forms. The more derived zoarcids are characterized by having 6-11 suborbital bones arranged in an angled, or “L”-shaped" pattern away from the orbit (except a few which have lost some bones) and the loss of the interorbital pores (except for some reversals in Lycenchelys and Lycodapus). Zoarcids are considered to have originated in the North Pacific Ocean, perhaps as early as the Eocene, when a pre-percoid radiation occurred. The suborder Zoarcoidei (today some 8-9 families) spread across the Pacific rim. Among Zoarcidae, a pre-Miocene radiation took place along the western coasts of the Americas, with areas of endemism forming in the Magellan Province of South America and Antarctica. Subsequent spreading back into northern waters occurred in Melanostigma and Pachycara. , Rhodes University Libraries (Digitisation)
- Full Text:
- Date Issued: 1994
Static analysis of functional languages
- Authors: Mountjoy, Jon-Dean
- Date: 1994 , 2012-10-10
- Subjects: Functional programming languages
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4669 , http://hdl.handle.net/10962/d1006690 , Functional programming languages
- Description: Static analysis is the name given to a number of compile time analysis techniques used to automatically generate information which can lead to improvements in the execution performance of function languages. This thesis provides an introduction to these techniques and their implementation. The abstract interpretation framework is an example of a technique used to extract information from a program by providing the program with an alternate semantics and evaluating this program over a non-standard domain. The elements of this domain represent certain properties of interest. This framework is examined in detail, as well as various extensions and variants of it. The use of binary logical relations and program logics as alternative formulations of the framework , and partial equivalence relations as an extension to it, are also looked at. The projection analysis framework determines how much of a sub-expression can be evaluated by examining the context in which the expression is to be evaluated, and provides an elegant method for finding particular types of information from data structures. This is also examined. The most costly operation in implementing an analysis is the computation of fixed points. Methods developed to make this process more efficient are looked at. This leads to the final chapter which highlights the dependencies and relationships between the different frameworks and their mathematical disciplines. , KMBT_223
- Full Text:
- Date Issued: 1994
- Authors: Mountjoy, Jon-Dean
- Date: 1994 , 2012-10-10
- Subjects: Functional programming languages
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4669 , http://hdl.handle.net/10962/d1006690 , Functional programming languages
- Description: Static analysis is the name given to a number of compile time analysis techniques used to automatically generate information which can lead to improvements in the execution performance of function languages. This thesis provides an introduction to these techniques and their implementation. The abstract interpretation framework is an example of a technique used to extract information from a program by providing the program with an alternate semantics and evaluating this program over a non-standard domain. The elements of this domain represent certain properties of interest. This framework is examined in detail, as well as various extensions and variants of it. The use of binary logical relations and program logics as alternative formulations of the framework , and partial equivalence relations as an extension to it, are also looked at. The projection analysis framework determines how much of a sub-expression can be evaluated by examining the context in which the expression is to be evaluated, and provides an elegant method for finding particular types of information from data structures. This is also examined. The most costly operation in implementing an analysis is the computation of fixed points. Methods developed to make this process more efficient are looked at. This leads to the final chapter which highlights the dependencies and relationships between the different frameworks and their mathematical disciplines. , KMBT_223
- Full Text:
- Date Issued: 1994
Babesia canis : a characterization of five field stocks in Southern Africa
- Authors: Van Heerden, Garth William
- Date: 1994
- Subjects: Babesia canis -- Africa, Southern , Tick-borne diseases -- Africa, Southern , Dogs -- Parasites
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5645 , http://hdl.handle.net/10962/d1005327 , Babesia canis -- Africa, Southern , Tick-borne diseases -- Africa, Southern , Dogs -- Parasites
- Description: This study attempted to characterise 5 field stocks of B. canis, collected from various geographic areas of southern Africa in terms of pathogenicity, immune response, cross resistance and antigenic composition. This was done by means of artificial infection of two to four year old Beagle dogs. Serological tests included indirect fluorescent antibody tests, polyacrylamide gel electrophoresis , Western blotting of B. canis antigen and immune serum transfers. The ZIM1, GHT1 , QTN1 and DBN1 stocks were found to be virulent and the JHB1 stock, which might be a cardiac form of babesiosis, was found to be highly virulent. Immune responses of dogs to primary challenges were poor. A second challenge or relapse was important in the development of a resistant immunity. Heterologous challenges showed that dogs which were immune to the ZIM1, QTN1 and DBN1 stocks were partially immune to the JHB1 stock. The dog that was immune to the GHT1 stock was the only one that was totally resistant to the JHB1 stock. Western blots revealed interstock antigenic variation between the JHB1 and the other four stocks. These differences were, however, not great enough to separate the stocks taxonomically.
- Full Text:
- Date Issued: 1994
- Authors: Van Heerden, Garth William
- Date: 1994
- Subjects: Babesia canis -- Africa, Southern , Tick-borne diseases -- Africa, Southern , Dogs -- Parasites
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5645 , http://hdl.handle.net/10962/d1005327 , Babesia canis -- Africa, Southern , Tick-borne diseases -- Africa, Southern , Dogs -- Parasites
- Description: This study attempted to characterise 5 field stocks of B. canis, collected from various geographic areas of southern Africa in terms of pathogenicity, immune response, cross resistance and antigenic composition. This was done by means of artificial infection of two to four year old Beagle dogs. Serological tests included indirect fluorescent antibody tests, polyacrylamide gel electrophoresis , Western blotting of B. canis antigen and immune serum transfers. The ZIM1, GHT1 , QTN1 and DBN1 stocks were found to be virulent and the JHB1 stock, which might be a cardiac form of babesiosis, was found to be highly virulent. Immune responses of dogs to primary challenges were poor. A second challenge or relapse was important in the development of a resistant immunity. Heterologous challenges showed that dogs which were immune to the ZIM1, QTN1 and DBN1 stocks were partially immune to the JHB1 stock. The dog that was immune to the GHT1 stock was the only one that was totally resistant to the JHB1 stock. Western blots revealed interstock antigenic variation between the JHB1 and the other four stocks. These differences were, however, not great enough to separate the stocks taxonomically.
- Full Text:
- Date Issued: 1994
An investigation into the present state of school guidance in Ciskeian secondary schools in the Keiskammahoek area
- Authors: Lombo, Mzimkhulu Solomon
- Date: 1994
- Subjects: Educational counseling -- Keiskammahoek
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1613 , http://hdl.handle.net/10962/d1003495
- Description: Although school guidance and counselling services were established in Ciskeian Secondary Schools in the early 1980's, little appears to be taking place. One is continually hearing the plea for an improvement in the system, but once again little is happening. Before such improvement can take place, however, it needs to be known what exactly is and isn't taking place. Furthermore, the problems preventing the services from operating successfully need to be clarified. This research aims at describing the state of guidance in a group of five secondary schools in the Keiskammahoek area of the Ciskei, and elucidating the problems experienced by practitioners in the field. An open-ended questionnaire was administered to 98 pupils and 18 guidance teachers, and the five principals of these schools were interviewed. The findings, which are discussed in detail, confirm the suspicions of the researcher that little guidance indeed is taking place. Many reasons for this state of affairs are given. Finally, suggestions are made as to how this unsatisfactory situation may be improved.
- Full Text:
- Date Issued: 1994
- Authors: Lombo, Mzimkhulu Solomon
- Date: 1994
- Subjects: Educational counseling -- Keiskammahoek
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1613 , http://hdl.handle.net/10962/d1003495
- Description: Although school guidance and counselling services were established in Ciskeian Secondary Schools in the early 1980's, little appears to be taking place. One is continually hearing the plea for an improvement in the system, but once again little is happening. Before such improvement can take place, however, it needs to be known what exactly is and isn't taking place. Furthermore, the problems preventing the services from operating successfully need to be clarified. This research aims at describing the state of guidance in a group of five secondary schools in the Keiskammahoek area of the Ciskei, and elucidating the problems experienced by practitioners in the field. An open-ended questionnaire was administered to 98 pupils and 18 guidance teachers, and the five principals of these schools were interviewed. The findings, which are discussed in detail, confirm the suspicions of the researcher that little guidance indeed is taking place. Many reasons for this state of affairs are given. Finally, suggestions are made as to how this unsatisfactory situation may be improved.
- Full Text:
- Date Issued: 1994
A basic guide to the Reconstruction and Development Programme
- Authors: African National Congress
- Date: 1994
- Subjects: Reconstruction and development programme (South Africa) , South Africa -- Economic policy , South Africa -- Social policy , African National Congress
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10962/75927 , vital:30483 , 1874902062
- Description: The RDP is a plan to address the many social and economic problems facing our country — problems such as...violence, lack of housing, lack of jobs, inadequate education and health care, lack of democracy, a failing economy. The RDP recognises that all of these problems are connected. For example, we cannot successfully build the economy while millions do not have homes or jobs. And we cannot provide homes and jobs without rebuilding the economy. We need policies and strategies to address all of the problems together. The RDP aims to do this. The RDP is a programme to mobilise all our people and all our resources to finally get rid of apartheid and build a democratic, non racial and non sexist future. The RDP was drawn up by the ANC-led alliance in consultation with other key mass organisations and assisted by a wide range of nongovernmental organisations (NGOs) and research organisations. This inclusive approach to developing and implementing policy — involving as many organisations as possible — is unique in South Africa’s political history. The ANC — because it is a liberation movement and based on the traditions of the Freedom Charter — is the only political organisation which can bring together such a wide range of social movements, community-based organisations and numerous other sectors and formations. This widespread and broad-based support throughout South Africa will allow the ANC within a Government of National Unity successfully to implement the RDP.
- Full Text:
- Date Issued: 1994
- Authors: African National Congress
- Date: 1994
- Subjects: Reconstruction and development programme (South Africa) , South Africa -- Economic policy , South Africa -- Social policy , African National Congress
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10962/75927 , vital:30483 , 1874902062
- Description: The RDP is a plan to address the many social and economic problems facing our country — problems such as...violence, lack of housing, lack of jobs, inadequate education and health care, lack of democracy, a failing economy. The RDP recognises that all of these problems are connected. For example, we cannot successfully build the economy while millions do not have homes or jobs. And we cannot provide homes and jobs without rebuilding the economy. We need policies and strategies to address all of the problems together. The RDP aims to do this. The RDP is a programme to mobilise all our people and all our resources to finally get rid of apartheid and build a democratic, non racial and non sexist future. The RDP was drawn up by the ANC-led alliance in consultation with other key mass organisations and assisted by a wide range of nongovernmental organisations (NGOs) and research organisations. This inclusive approach to developing and implementing policy — involving as many organisations as possible — is unique in South Africa’s political history. The ANC — because it is a liberation movement and based on the traditions of the Freedom Charter — is the only political organisation which can bring together such a wide range of social movements, community-based organisations and numerous other sectors and formations. This widespread and broad-based support throughout South Africa will allow the ANC within a Government of National Unity successfully to implement the RDP.
- Full Text:
- Date Issued: 1994
Delineation of buried stream channels using geophysical techniques
- Authors: Biedler, Murray W
- Date: 1994
- Subjects: Stream channelization , Seismic refraction method , Electric prospecting , Electromagnetism , Aquifers -- South Africa , Groundwater , Hydrogeology -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4823 , http://hdl.handle.net/10962/d1005498 , Stream channelization , Seismic refraction method , Electric prospecting , Electromagnetism , Aquifers -- South Africa , Groundwater , Hydrogeology -- South Africa
- Description: This study sets out to evaluate the use of geophysical methods for delineating buried stream channels, which can act as zones of preferential flow within a less hydraulically conductive aquifer. This information is important for gaining an understanding of flow dynamics of alluvial systems. The most reliable method of delineating the dimensions of aquifers is by drilling, which is an expensive proposition and is best preceded by a preliminary geophysical study to help define target zones for a drilling program. The study area is located adjacent to the Coerney River in the Sundays River Valley. Geologically it consists of approximately 5 metres of alluvial fines, covering 3 metres of coarse cobbles and boulders, all underlain by alternating siltstone and sandstone beds of indeterminate thickness. Throughout the area the water is very shallow at approximately 2 metres depth and the groundwater tends to be very saline. An air photo study revealed an old oxbow channel that had been covered over by subsequent agricultural land use. The geophysical methods available for the study were portable seismic refraction, electrical resistivity and electromagnetics. Preliminary field tests clearly showed that seismics did not produce valid results. The methods of electrical resistivity and electromagnetics produced good data and were subjected to further assessment. A grid was surveyed over the study area and both geophysical methods were applied at regularly spaced stations. Soil samples were taken over the same survey grid and analyzed for electrical conductivity in a soils laboratory. The results were compared to the geophysical data in an attempt to quantify the relationship between geophysical response and soil salinity. The data from the electromagnetic survey showed areas of low electrical conductivity which was a possible indication of zones of preferential groundwater flow. A transect of boreholes was drilled over selected electrical conductivity lows and successfully intersected the buried stream channel. A comparison of the borehole logs with the layered earth models from the Vertical Electrical Soundings indicated that the electrical resistivity method was not responding to the features of the buried stream channel and the cobblestone layer. This proved the electromagnetic method to be more valuable for this particular study
- Full Text:
- Date Issued: 1994
- Authors: Biedler, Murray W
- Date: 1994
- Subjects: Stream channelization , Seismic refraction method , Electric prospecting , Electromagnetism , Aquifers -- South Africa , Groundwater , Hydrogeology -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4823 , http://hdl.handle.net/10962/d1005498 , Stream channelization , Seismic refraction method , Electric prospecting , Electromagnetism , Aquifers -- South Africa , Groundwater , Hydrogeology -- South Africa
- Description: This study sets out to evaluate the use of geophysical methods for delineating buried stream channels, which can act as zones of preferential flow within a less hydraulically conductive aquifer. This information is important for gaining an understanding of flow dynamics of alluvial systems. The most reliable method of delineating the dimensions of aquifers is by drilling, which is an expensive proposition and is best preceded by a preliminary geophysical study to help define target zones for a drilling program. The study area is located adjacent to the Coerney River in the Sundays River Valley. Geologically it consists of approximately 5 metres of alluvial fines, covering 3 metres of coarse cobbles and boulders, all underlain by alternating siltstone and sandstone beds of indeterminate thickness. Throughout the area the water is very shallow at approximately 2 metres depth and the groundwater tends to be very saline. An air photo study revealed an old oxbow channel that had been covered over by subsequent agricultural land use. The geophysical methods available for the study were portable seismic refraction, electrical resistivity and electromagnetics. Preliminary field tests clearly showed that seismics did not produce valid results. The methods of electrical resistivity and electromagnetics produced good data and were subjected to further assessment. A grid was surveyed over the study area and both geophysical methods were applied at regularly spaced stations. Soil samples were taken over the same survey grid and analyzed for electrical conductivity in a soils laboratory. The results were compared to the geophysical data in an attempt to quantify the relationship between geophysical response and soil salinity. The data from the electromagnetic survey showed areas of low electrical conductivity which was a possible indication of zones of preferential groundwater flow. A transect of boreholes was drilled over selected electrical conductivity lows and successfully intersected the buried stream channel. A comparison of the borehole logs with the layered earth models from the Vertical Electrical Soundings indicated that the electrical resistivity method was not responding to the features of the buried stream channel and the cobblestone layer. This proved the electromagnetic method to be more valuable for this particular study
- Full Text:
- Date Issued: 1994
Synthesis and conformational studies of indolizines
- Authors: George, Rosemary
- Date: 1994
- Subjects: Indole alkaloids -- Research , Organic compounds -- Synthesis , Chemistry, Organic
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4367 , http://hdl.handle.net/10962/d1005032 , Indole alkaloids -- Research , Organic compounds -- Synthesis , Chemistry, Organic
- Description: The present investigation has involved a kinetic and mechanistic study of the thermal cyclization of 3-acetoxy-3-(2-pyridyl)-2-methylenepropanoate esters and related compounds to 2-substituted indolizines. Substrates for the kinetic study were prepared via the Baylis-Hillmann reaction of pyridine-2-carboxaldehydes with acrylate esters, acrylonitrile and methyl vinyl ketone. The resulting hydroxy compounds were then acetylated to afford the acetoxy derivatives, thermal cyclization of which gave the corresponding 2-substituted indolizines. The cyclization reactions was followed using 'H NMR spectroscopy and were shown to follow firstorder kinetics. The influence of the various substituents on the observed first-order rate constants has been examined and variable temperature studies have permitted evaluation of activation parameters for the formation of methyl indolizine-2-carboxylate and ethyl indolizine-2-carboxylate. An alternative route to 2-substituted indolizines via halogenated derivatives was explored and several halogenated 2-pyridyl derivatives were synthesised and their thermal cyclization to indolizines was attempted. Novel 5-methylindolizine-2-carboxamides were prepared as part of this investigation and dynamic NMR spectroscopy was used to study internal rotation about the amide N-CO bond in these compounds.
- Full Text:
- Date Issued: 1994
- Authors: George, Rosemary
- Date: 1994
- Subjects: Indole alkaloids -- Research , Organic compounds -- Synthesis , Chemistry, Organic
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4367 , http://hdl.handle.net/10962/d1005032 , Indole alkaloids -- Research , Organic compounds -- Synthesis , Chemistry, Organic
- Description: The present investigation has involved a kinetic and mechanistic study of the thermal cyclization of 3-acetoxy-3-(2-pyridyl)-2-methylenepropanoate esters and related compounds to 2-substituted indolizines. Substrates for the kinetic study were prepared via the Baylis-Hillmann reaction of pyridine-2-carboxaldehydes with acrylate esters, acrylonitrile and methyl vinyl ketone. The resulting hydroxy compounds were then acetylated to afford the acetoxy derivatives, thermal cyclization of which gave the corresponding 2-substituted indolizines. The cyclization reactions was followed using 'H NMR spectroscopy and were shown to follow firstorder kinetics. The influence of the various substituents on the observed first-order rate constants has been examined and variable temperature studies have permitted evaluation of activation parameters for the formation of methyl indolizine-2-carboxylate and ethyl indolizine-2-carboxylate. An alternative route to 2-substituted indolizines via halogenated derivatives was explored and several halogenated 2-pyridyl derivatives were synthesised and their thermal cyclization to indolizines was attempted. Novel 5-methylindolizine-2-carboxamides were prepared as part of this investigation and dynamic NMR spectroscopy was used to study internal rotation about the amide N-CO bond in these compounds.
- Full Text:
- Date Issued: 1994
Inauguration photo of Nelson Mandela in 1994 with the founder of the Centre for women, Dr Mercy Oduyoye, Dr Nita Barrow of Barbados, Archbishop Ted Scott and Dr. Brigalia Bam
- Date: 1994 , 2022-10-06
- Subjects: Bam, Brigalia
- Language: English
- Type: photograph , realia
- Identifier: http://hdl.handle.net/10948/56975 , vital:57209
- Description: Inauguration photo of Nelson Mandela in 1994 with the founder of the Centre for Women, Dr Mercy Oduyoye, Dr Nita Barrow of Barbados, Archbishop Ted Scott and Dr. Brigalia Bam. , Donated/gifted to Nelson Mandela University Archives , Forms part of: Brigalia Bam collection
- Full Text: false
- Date Issued: 1994
- Date: 1994 , 2022-10-06
- Subjects: Bam, Brigalia
- Language: English
- Type: photograph , realia
- Identifier: http://hdl.handle.net/10948/56975 , vital:57209
- Description: Inauguration photo of Nelson Mandela in 1994 with the founder of the Centre for Women, Dr Mercy Oduyoye, Dr Nita Barrow of Barbados, Archbishop Ted Scott and Dr. Brigalia Bam. , Donated/gifted to Nelson Mandela University Archives , Forms part of: Brigalia Bam collection
- Full Text: false
- Date Issued: 1994
The impact of structural adjustment programmes upon the political economy of Zambia: a critical analysis
- Authors: Makan, Amita
- Date: 1994
- Subjects: Structural adjustment (Economic policy) -- Zambia , Zambia -- Economic conditions -- 1964- , Zambia -- Politics and government -- 1964-1991 , Zambia -- Economic conditions
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2800 , http://hdl.handle.net/10962/d1003010 , Structural adjustment (Economic policy) -- Zambia , Zambia -- Economic conditions -- 1964- , Zambia -- Politics and government -- 1964-1991 , Zambia -- Economic conditions
- Description: This study begins with a statistical survey setting out the parameters of Zambia's socio-economic decline in the 1980s. In order to unravel the complex reasons for the crisis, the study develops and employs an historical structural framework which emphasises the interconnectedness of historical, political, economic and social processes . Thereafter, an explanation of Zambia's political and economic development is presented as a background for understanding how and why the IMF came to play an increasingly decisive role in the management of the economic crisis in the 1980s. It is argued that patron-client politics in conjunction with a 'coincidence of interests' between local elite and international capital, entrenched the distorted mono-export dependent economy which, in turn, accelerated the economic decline and debt crisis of the 1980s. After presenting an overview of the Fund's philosophy and objectives, close attention is paid to the impact of SAPs on Zambia, especially in terms of how such policies as subsidy withdrawal, de-regulation and devaluation affected the economy, debt-reduction, health and education. While there is no incontrovertible evidence that adjustment policies caused the crisis, they have been largely ineffective in reversing Zambia's economic decline. In fact, due to the IMF's ahistorical and apolitical approach, any gains have been ephemeral and, in many instances, served to exacerbate the suffering of the population. Finally, Zambia's political structures have proved unable and unwilling to implement IMF reforms consistently and this underlies the central point that SAPs, as a strategy, cannot ensure long-term sustainable development.
- Full Text:
- Date Issued: 1994
- Authors: Makan, Amita
- Date: 1994
- Subjects: Structural adjustment (Economic policy) -- Zambia , Zambia -- Economic conditions -- 1964- , Zambia -- Politics and government -- 1964-1991 , Zambia -- Economic conditions
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2800 , http://hdl.handle.net/10962/d1003010 , Structural adjustment (Economic policy) -- Zambia , Zambia -- Economic conditions -- 1964- , Zambia -- Politics and government -- 1964-1991 , Zambia -- Economic conditions
- Description: This study begins with a statistical survey setting out the parameters of Zambia's socio-economic decline in the 1980s. In order to unravel the complex reasons for the crisis, the study develops and employs an historical structural framework which emphasises the interconnectedness of historical, political, economic and social processes . Thereafter, an explanation of Zambia's political and economic development is presented as a background for understanding how and why the IMF came to play an increasingly decisive role in the management of the economic crisis in the 1980s. It is argued that patron-client politics in conjunction with a 'coincidence of interests' between local elite and international capital, entrenched the distorted mono-export dependent economy which, in turn, accelerated the economic decline and debt crisis of the 1980s. After presenting an overview of the Fund's philosophy and objectives, close attention is paid to the impact of SAPs on Zambia, especially in terms of how such policies as subsidy withdrawal, de-regulation and devaluation affected the economy, debt-reduction, health and education. While there is no incontrovertible evidence that adjustment policies caused the crisis, they have been largely ineffective in reversing Zambia's economic decline. In fact, due to the IMF's ahistorical and apolitical approach, any gains have been ephemeral and, in many instances, served to exacerbate the suffering of the population. Finally, Zambia's political structures have proved unable and unwilling to implement IMF reforms consistently and this underlies the central point that SAPs, as a strategy, cannot ensure long-term sustainable development.
- Full Text:
- Date Issued: 1994
"We are all friends here": the social dynamics of a development project
- Authors: Ainslie, Andrew
- Date: 1994
- Subjects: St Mark's Mission (South Africa) St Mark's Community Project Rural development -- South Africa -- Eastern Cape Community development -- South Africa Cooperative marketing of agricultural produce -- South Africa Women in community development -- South Africa Women in cooperative societies -- South Africa Sex role in the work environment -- South Africa World Vision International Eastern Cape (South Africa) -- Rural conditions
- Language: English
- Type: Book , Text
- Identifier: http://hdl.handle.net/10962/1663 , vital:20214 , ISBN 0868102660
- Description: In 1978, a Rev. John Galela, then a minister at St.Mark's, launched a project which included pig-farming and the growing of vegetables for human consumption and to feed the pigs. With a grant from the South African Council of Churches (SACC), a pump was installed on the banks of the river and vegetables were grown under irrigation on 2,4 ha of land. This pilot project did not affect the leasing arrangements mentioned above. The project apparently enjoyed the approval and support of the local community, until the chief, Chief M.D. Feketha (an influential member of the Ciskeian cabinet at this time), came to hear of it and forbade the people of Newlands, who fall under his "tribal" jurisdiction, to participate in the project. , Digitised by Rhodes University Library on behalf of the Institute of Social and Economic Research (ISER)
- Full Text:
- Date Issued: 1994
- Authors: Ainslie, Andrew
- Date: 1994
- Subjects: St Mark's Mission (South Africa) St Mark's Community Project Rural development -- South Africa -- Eastern Cape Community development -- South Africa Cooperative marketing of agricultural produce -- South Africa Women in community development -- South Africa Women in cooperative societies -- South Africa Sex role in the work environment -- South Africa World Vision International Eastern Cape (South Africa) -- Rural conditions
- Language: English
- Type: Book , Text
- Identifier: http://hdl.handle.net/10962/1663 , vital:20214 , ISBN 0868102660
- Description: In 1978, a Rev. John Galela, then a minister at St.Mark's, launched a project which included pig-farming and the growing of vegetables for human consumption and to feed the pigs. With a grant from the South African Council of Churches (SACC), a pump was installed on the banks of the river and vegetables were grown under irrigation on 2,4 ha of land. This pilot project did not affect the leasing arrangements mentioned above. The project apparently enjoyed the approval and support of the local community, until the chief, Chief M.D. Feketha (an influential member of the Ciskeian cabinet at this time), came to hear of it and forbade the people of Newlands, who fall under his "tribal" jurisdiction, to participate in the project. , Digitised by Rhodes University Library on behalf of the Institute of Social and Economic Research (ISER)
- Full Text:
- Date Issued: 1994
Case studies of tutors' responses to student writing and the way in which students interpret these
- Authors: Paxton, Moragh Isobel Jane
- Date: 1994
- Subjects: Written communication -- Study and teaching -- South Africa Written communication -- South Africa -- Case studies Grading and marking (Students) -- Case studies
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1430 , http://hdl.handle.net/10962/d1003311
- Description: This thesis examines tutor feedback on student essays to ascertain the extent to which these responses assist in teaching the academic and specific disciplinary conventions and to determine what is effective feedback and what is not. The investigation constituted an evaluation of a small sample of essays and the framework for this evaluation was developed from a study of current theories of literacy and language teaching. It was further informed by data gathered from interviews with students and tutors and questionnaires completed by them. This was done in order to establish how students interpret and react to feedback and to demonstrate the level of understanding between tutors and students in this mode of communication. The conclusion was that tutor feedback can provide a valuable method for teaching the discourse of the discipline. However, results of the study revealed that communication often breaks down because tutors and students do not share a common language for talking about academic discourse and because students may not have understood the requirements of the task. In addition, the study found that responses to a small group of essays in the lowest mark category and written by second language students, were very inadequate. As the researcher, I concluded that graduate tutors were not well equipped for the task of dealing with these weaker essays. I have made suggestions for future research in this area and I believe that the data from this case study will provide valuable ideas for training tutors for responding to student essays.
- Full Text:
- Date Issued: 1994
- Authors: Paxton, Moragh Isobel Jane
- Date: 1994
- Subjects: Written communication -- Study and teaching -- South Africa Written communication -- South Africa -- Case studies Grading and marking (Students) -- Case studies
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1430 , http://hdl.handle.net/10962/d1003311
- Description: This thesis examines tutor feedback on student essays to ascertain the extent to which these responses assist in teaching the academic and specific disciplinary conventions and to determine what is effective feedback and what is not. The investigation constituted an evaluation of a small sample of essays and the framework for this evaluation was developed from a study of current theories of literacy and language teaching. It was further informed by data gathered from interviews with students and tutors and questionnaires completed by them. This was done in order to establish how students interpret and react to feedback and to demonstrate the level of understanding between tutors and students in this mode of communication. The conclusion was that tutor feedback can provide a valuable method for teaching the discourse of the discipline. However, results of the study revealed that communication often breaks down because tutors and students do not share a common language for talking about academic discourse and because students may not have understood the requirements of the task. In addition, the study found that responses to a small group of essays in the lowest mark category and written by second language students, were very inadequate. As the researcher, I concluded that graduate tutors were not well equipped for the task of dealing with these weaker essays. I have made suggestions for future research in this area and I believe that the data from this case study will provide valuable ideas for training tutors for responding to student essays.
- Full Text:
- Date Issued: 1994
The porphyry copper system and the precious metal-gold potential
- Authors: Gendall, Ian Richard
- Date: 1994
- Subjects: Copper ores , Porphyry , Gold ores -- Geology , Prospecting
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4992 , http://hdl.handle.net/10962/d1005604 , Copper ores , Porphyry , Gold ores -- Geology , Prospecting
- Description: It has been established that porphyry copper/copper-gold deposits have formed from I Ma to 2 Ga ago. Generally, they are related to the Mesozoic-Cenozoic interval with few reported occurrences from the Palaeozoic or Precambrian. A reason cited is the erosion of these deposits which are often related to convergent plate margins and orogenic belts. Observations of the alteration and mineralisation within and around porphyry copper/copper-gold systems have been included in numerous idealised models. These alteration and mineralisation patterns are dependent on the phases of intrusion, the tectonic setting and rock type, depth of emplacement and relationship to coeval volcanics, physiochemical conditions operative within and surrounding the intrusive and many other mechanical and geochemical conditions. Island arc and cratonic arc/margin deposits are generally considered to be richer in gold than their molybdenum-rich, intra-cratonic counterparts. Metal zonation may occur around these copper/copper-gold deposits, e.g. copper in the core moving out to silver, lead, zinc and gold. This zonation is not always present and gold may occur in the core, intermediate or distal zones. Examples of gold-rich porphyry deposits from British Columbia, Chile and the SW Pacific Island regions suggest gold is closely associated with the potassic-rich zones. Generally these gold-rich zones have greater than 2% magnetite and a high oxygen fugacity is considered to be an important control for gold deposition. High Cl contents within the magma are necessary for gold mobility within the host intrusive centres. Beyond this zone HS₂ becomes an important transporting ligand. Exploration for porphyry copper-gold deposits includes an integrated geological, geophysical and geochemical approach. Petrographic work through to Landsat imagery may be used to determine the chemical conditions of the system, ore association, favourable structural zones and alteration patterns, in order to focus exploration activities.
- Full Text:
- Date Issued: 1994
- Authors: Gendall, Ian Richard
- Date: 1994
- Subjects: Copper ores , Porphyry , Gold ores -- Geology , Prospecting
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4992 , http://hdl.handle.net/10962/d1005604 , Copper ores , Porphyry , Gold ores -- Geology , Prospecting
- Description: It has been established that porphyry copper/copper-gold deposits have formed from I Ma to 2 Ga ago. Generally, they are related to the Mesozoic-Cenozoic interval with few reported occurrences from the Palaeozoic or Precambrian. A reason cited is the erosion of these deposits which are often related to convergent plate margins and orogenic belts. Observations of the alteration and mineralisation within and around porphyry copper/copper-gold systems have been included in numerous idealised models. These alteration and mineralisation patterns are dependent on the phases of intrusion, the tectonic setting and rock type, depth of emplacement and relationship to coeval volcanics, physiochemical conditions operative within and surrounding the intrusive and many other mechanical and geochemical conditions. Island arc and cratonic arc/margin deposits are generally considered to be richer in gold than their molybdenum-rich, intra-cratonic counterparts. Metal zonation may occur around these copper/copper-gold deposits, e.g. copper in the core moving out to silver, lead, zinc and gold. This zonation is not always present and gold may occur in the core, intermediate or distal zones. Examples of gold-rich porphyry deposits from British Columbia, Chile and the SW Pacific Island regions suggest gold is closely associated with the potassic-rich zones. Generally these gold-rich zones have greater than 2% magnetite and a high oxygen fugacity is considered to be an important control for gold deposition. High Cl contents within the magma are necessary for gold mobility within the host intrusive centres. Beyond this zone HS₂ becomes an important transporting ligand. Exploration for porphyry copper-gold deposits includes an integrated geological, geophysical and geochemical approach. Petrographic work through to Landsat imagery may be used to determine the chemical conditions of the system, ore association, favourable structural zones and alteration patterns, in order to focus exploration activities.
- Full Text:
- Date Issued: 1994
Farmers' strategies and their implications for land reform in the Orange Free State
- Authors: Beinart, William
- Date: 1994
- Subjects: Agriculture -- Orange Free State Land reform -- South Africa -- Orange Free State Land tenure -- Orange Free State
- Language: English
- Type: text , Manuscript
- Identifier: http://hdl.handle.net/10962/2813 , vital:20328
- Description: It is possible to conjure a wide variety of future agricultural scenarios in South Africa. But new policies should be developed only with close attention to what exists and what is feasible. Analysis of the potential for land reform should remain sensitive to local ecological and economic conditions and to the current strategies of both farmers and dispossessed. Rural life for many people remains insecure. Farmworkers are particularly vulnerable at present and might become more so in a phase of rapid reform and uncertainty. Although the most carefully planned strategy of reform might be undermined by the sheer demand for land or informal reoccupations, the aims of restitution, justice and redistribution should be tempered by the equally difficult demands of production. Drawing on material from a local research project in the Orange Free State (OFS), done jointly with Colin Murray, this article concentrates on three issues: patterns of land ownership; farming strategies; and land availability. The position of farmworkers and those who have recently moved off farms, as well as the potential for new patterns of occupation will be addressed in subsequent project papers (Murray, 1993). , Digitised by Rhodes University Library on behalf of the Institute of Social and Economic Research (ISER)
- Full Text:
- Date Issued: 1994
- Authors: Beinart, William
- Date: 1994
- Subjects: Agriculture -- Orange Free State Land reform -- South Africa -- Orange Free State Land tenure -- Orange Free State
- Language: English
- Type: text , Manuscript
- Identifier: http://hdl.handle.net/10962/2813 , vital:20328
- Description: It is possible to conjure a wide variety of future agricultural scenarios in South Africa. But new policies should be developed only with close attention to what exists and what is feasible. Analysis of the potential for land reform should remain sensitive to local ecological and economic conditions and to the current strategies of both farmers and dispossessed. Rural life for many people remains insecure. Farmworkers are particularly vulnerable at present and might become more so in a phase of rapid reform and uncertainty. Although the most carefully planned strategy of reform might be undermined by the sheer demand for land or informal reoccupations, the aims of restitution, justice and redistribution should be tempered by the equally difficult demands of production. Drawing on material from a local research project in the Orange Free State (OFS), done jointly with Colin Murray, this article concentrates on three issues: patterns of land ownership; farming strategies; and land availability. The position of farmworkers and those who have recently moved off farms, as well as the potential for new patterns of occupation will be addressed in subsequent project papers (Murray, 1993). , Digitised by Rhodes University Library on behalf of the Institute of Social and Economic Research (ISER)
- Full Text:
- Date Issued: 1994
The comprehension of figurative language in English literary texts by students for whom English is not a mother tongue
- Authors: Winberg, Christine
- Date: 1994
- Subjects: English language -- Study and teaching -- Foreign speakers , English literature -- Study and teaching (Higher) , Context (Linguistics) , Metaphor , Figures of speech
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2366 , http://hdl.handle.net/10962/d1002649 , English language -- Study and teaching -- Foreign speakers , English literature -- Study and teaching (Higher) , Context (Linguistics) , Metaphor , Figures of speech
- Description: This study applies Sperber and Wilson's relevance theory to the comprehension of figurative language in poetry. Students' understanding of metaphor as a linguistic category and comprehension of metaphorical texts are analysed in terms of the principle of relevance. Patterns of comprehension in English first language (Ll) and English second language (ESL) students' analyses of metaphorical texts are discussed and through an analysis of similarities and differences in these patterns of comprehension an attempt is made to develop a pedagogy around relevance theory. Relevance theory's particular emphasis on the role played by "context" in cognition is seen to have significance for the teaching of literature in South African universities. Relevance theory's account of cognition generates a range of educational principles which could be specifically applied to the teaching of metaphor. An appraisal of the strengths and difficulties students experience in expressing their understanding of metaphor in an academic context is included. This was done to further develop relevance theory into a pedagogical approach which takes into account the academic context in which writing occurs. The investigation of the particular difficulties that English metaphor poses for ESL students entailed acquiring a working knowledge of the ways in which metaphor is taught and assessed in DET schools. The interpretations of students of different linguistic, social and educational backgrounds reveal unifying elements that could be incorporated into a pedagogy based on relevance theory. Such a pedagogy would be appropriate to the multilingual/multicultural/multiracial nature of classes in South African universities and would be a more empowering approach to the teaching of English metaphor.
- Full Text:
- Date Issued: 1994
- Authors: Winberg, Christine
- Date: 1994
- Subjects: English language -- Study and teaching -- Foreign speakers , English literature -- Study and teaching (Higher) , Context (Linguistics) , Metaphor , Figures of speech
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2366 , http://hdl.handle.net/10962/d1002649 , English language -- Study and teaching -- Foreign speakers , English literature -- Study and teaching (Higher) , Context (Linguistics) , Metaphor , Figures of speech
- Description: This study applies Sperber and Wilson's relevance theory to the comprehension of figurative language in poetry. Students' understanding of metaphor as a linguistic category and comprehension of metaphorical texts are analysed in terms of the principle of relevance. Patterns of comprehension in English first language (Ll) and English second language (ESL) students' analyses of metaphorical texts are discussed and through an analysis of similarities and differences in these patterns of comprehension an attempt is made to develop a pedagogy around relevance theory. Relevance theory's particular emphasis on the role played by "context" in cognition is seen to have significance for the teaching of literature in South African universities. Relevance theory's account of cognition generates a range of educational principles which could be specifically applied to the teaching of metaphor. An appraisal of the strengths and difficulties students experience in expressing their understanding of metaphor in an academic context is included. This was done to further develop relevance theory into a pedagogical approach which takes into account the academic context in which writing occurs. The investigation of the particular difficulties that English metaphor poses for ESL students entailed acquiring a working knowledge of the ways in which metaphor is taught and assessed in DET schools. The interpretations of students of different linguistic, social and educational backgrounds reveal unifying elements that could be incorporated into a pedagogy based on relevance theory. Such a pedagogy would be appropriate to the multilingual/multicultural/multiracial nature of classes in South African universities and would be a more empowering approach to the teaching of English metaphor.
- Full Text:
- Date Issued: 1994
A classroom-based investigation into the potential of a computer-mediated criterion-referenced test as an evaluation instrument for the assessment of primary end user spreadsheet skills
- Authors: Benn, Kenneth Robert Andrew
- Date: 1994
- Subjects: Education -- Data processing Electronic spreadsheets Criterion-referenced tests Educational tests and measurements
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1447 , http://hdl.handle.net/10962/d1003328
- Description: The demand for innovative end users of information technology is increasing along with the proliferation of computer equipment within the workplace. This has resulted in increasing demands being made upon educational institutions responsible for the education of computer end users. The demands placed upon the teachers are particularly high. Large class groups and limited physical resources make the task especially difficult. One of the most time consuming, yet important, tasks is that of student evaluation. To effectively assess the practical work of information technology students requires intensive study of the storage media upon which the students'efforts have been saved. The purpose of this study was to assess the suitability of criterion-referenced testing techniques applied to the evaluation of end user computing students. Objective questions were administered to the students using Question Mark, a computer-managed test delivery system which enabled quick and efficient management of scoring and data manipulation for empirical analysis. The study was limited to the classroom situation and the assessment of primary spreadsheet skills. In order to operate within these boundaries, empirical techniques were used which enabled the timeous analysis of the students' test results. The findings of this study proved to be encouraging. Computer-mediated criterion-referenced testing techniques were found to be sufficiently reliable for classroom practice when used to assess primary spreadsheet skills. The validation of the assessment technique proved to be problematic because of the constraints imposed by normal classroom practice as well as the lack of an established methodology for evaluating spreadsheet skills. However, sufficient evidence was obtained to warrant further research aimed at assessing the use of computer-mediated criterion-referenced tests to evaluate information technology end user learning in situations beyond the boundaries of the classroom, such as a national certification examination.
- Full Text:
- Date Issued: 1994
- Authors: Benn, Kenneth Robert Andrew
- Date: 1994
- Subjects: Education -- Data processing Electronic spreadsheets Criterion-referenced tests Educational tests and measurements
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1447 , http://hdl.handle.net/10962/d1003328
- Description: The demand for innovative end users of information technology is increasing along with the proliferation of computer equipment within the workplace. This has resulted in increasing demands being made upon educational institutions responsible for the education of computer end users. The demands placed upon the teachers are particularly high. Large class groups and limited physical resources make the task especially difficult. One of the most time consuming, yet important, tasks is that of student evaluation. To effectively assess the practical work of information technology students requires intensive study of the storage media upon which the students'efforts have been saved. The purpose of this study was to assess the suitability of criterion-referenced testing techniques applied to the evaluation of end user computing students. Objective questions were administered to the students using Question Mark, a computer-managed test delivery system which enabled quick and efficient management of scoring and data manipulation for empirical analysis. The study was limited to the classroom situation and the assessment of primary spreadsheet skills. In order to operate within these boundaries, empirical techniques were used which enabled the timeous analysis of the students' test results. The findings of this study proved to be encouraging. Computer-mediated criterion-referenced testing techniques were found to be sufficiently reliable for classroom practice when used to assess primary spreadsheet skills. The validation of the assessment technique proved to be problematic because of the constraints imposed by normal classroom practice as well as the lack of an established methodology for evaluating spreadsheet skills. However, sufficient evidence was obtained to warrant further research aimed at assessing the use of computer-mediated criterion-referenced tests to evaluate information technology end user learning in situations beyond the boundaries of the classroom, such as a national certification examination.
- Full Text:
- Date Issued: 1994