A description of gametogenesis in the panga Pterogymnus laniarius (Pisces: Sparidae) with comments on changes in maturity patterns over the past two decades
- Booth, Anthony J, Hecht, Thomas
- Authors: Booth, Anthony J , Hecht, Thomas
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/123542 , vital:35452 , https://doi.org/10.1080/02541858.1997.11448428
- Description: A description of gametogenesis in the panga Pferogymnus laniarius, a common endemic seabream species inhabiting the Agulhas Bank, South Africa, is presented. After sexual maturity, oogenesis and spermatogenesis continued throughout the year and were found to be similar to these processes in other seabream species and teleosts in general. Analysis of maturity data over the past two decades revealed a significant change in both age and size-at-maturity, a response to fishing pressure.
- Full Text:
- Date Issued: 2015
- Authors: Booth, Anthony J , Hecht, Thomas
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/123542 , vital:35452 , https://doi.org/10.1080/02541858.1997.11448428
- Description: A description of gametogenesis in the panga Pferogymnus laniarius, a common endemic seabream species inhabiting the Agulhas Bank, South Africa, is presented. After sexual maturity, oogenesis and spermatogenesis continued throughout the year and were found to be similar to these processes in other seabream species and teleosts in general. Analysis of maturity data over the past two decades revealed a significant change in both age and size-at-maturity, a response to fishing pressure.
- Full Text:
- Date Issued: 2015
Stratigraphy and age of Karoo basalts of Lesotho and implications for correlations within the Karoo igneous province
- Marsh, Julian S, Hooper, P R, Rehacek, J, Duncan, R A, Duncan, Andrew R
- Authors: Marsh, Julian S , Hooper, P R , Rehacek, J , Duncan, R A , Duncan, Andrew R
- Date: 2013
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/149507 , vital:38859 , https://doi.org/10.1029/GM100p0247
- Description: Remnants of the erupted and intrusive products of the Karoo igneous province, one of the classic Mesozoic continental flood basalt provinces, are found throughout southern Africa. Such large continental igneous events are frequently ascribed to the rise of deep-seated mantle plumes and, in some instances, are thought to be related to continental breakup.
- Full Text: false
- Date Issued: 2013
- Authors: Marsh, Julian S , Hooper, P R , Rehacek, J , Duncan, R A , Duncan, Andrew R
- Date: 2013
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/149507 , vital:38859 , https://doi.org/10.1029/GM100p0247
- Description: Remnants of the erupted and intrusive products of the Karoo igneous province, one of the classic Mesozoic continental flood basalt provinces, are found throughout southern Africa. Such large continental igneous events are frequently ascribed to the rise of deep-seated mantle plumes and, in some instances, are thought to be related to continental breakup.
- Full Text: false
- Date Issued: 2013
A model for the analysis of small group interaction–and beyond?:
- Authors: Hunt, Sally
- Date: 2012
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/139171 , vital:37711 , DOI: 10.1080/10118063.1997.9724122
- Description: This article describes a branching model developed for the analysis of interaction in small teaching groups in a tertiary setting. Based within Conversation Analysis, the model constitutes a set of justifications for the validity of utterances in terms of their place on the conversational floor. Examples of the classifications included in the model are provided from a broader study of interaction in tutorials at an Eastern Cape university. It is suggested that while the model was developed for a specific context, it could be adapted for use in a variety of contexts.
- Full Text:
- Date Issued: 2012
- Authors: Hunt, Sally
- Date: 2012
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/139171 , vital:37711 , DOI: 10.1080/10118063.1997.9724122
- Description: This article describes a branching model developed for the analysis of interaction in small teaching groups in a tertiary setting. Based within Conversation Analysis, the model constitutes a set of justifications for the validity of utterances in terms of their place on the conversational floor. Examples of the classifications included in the model are provided from a broader study of interaction in tutorials at an Eastern Cape university. It is suggested that while the model was developed for a specific context, it could be adapted for use in a variety of contexts.
- Full Text:
- Date Issued: 2012
The effects of economic incentives in controlling pollution in the South African leather industry: die uitwerking van ekonomiese insentiewe op die beheer van besoedeling in die Suid-Afrikaanse leerbedryf
- Mowat, Shaun P, Antrobus, Geoffrey G, Fraser, Gavin C G
- Authors: Mowat, Shaun P , Antrobus, Geoffrey G , Fraser, Gavin C G
- Date: 2010
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/143057 , vital:38197 , DOI: 10.1080/03031853.1997.9523487
- Description: Pollution of the environment is becoming an increasingly serious problem. A large contributor to this is industry which generates effluent as a by-product of its production process. Two methods of controlling the pollution generated by industry are the so-called “command and control” techniques and economic incentives. In theory, economic incentives promise a more economically efficient and equitable means of pollution control. This paper sets out to ascertain whether this would hold in practice by applying environmental economic theory to the practical problem of controlling the effluent generated by one particular industry, viz the South African leather industry.
- Full Text:
- Date Issued: 2010
- Authors: Mowat, Shaun P , Antrobus, Geoffrey G , Fraser, Gavin C G
- Date: 2010
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/143057 , vital:38197 , DOI: 10.1080/03031853.1997.9523487
- Description: Pollution of the environment is becoming an increasingly serious problem. A large contributor to this is industry which generates effluent as a by-product of its production process. Two methods of controlling the pollution generated by industry are the so-called “command and control” techniques and economic incentives. In theory, economic incentives promise a more economically efficient and equitable means of pollution control. This paper sets out to ascertain whether this would hold in practice by applying environmental economic theory to the practical problem of controlling the effluent generated by one particular industry, viz the South African leather industry.
- Full Text:
- Date Issued: 2010
A new species of the flatfish genus Chascanopsetta (Pleuronectiformes: Bothidae), from the coasts of Kenya and Somalia with comments on C.lugubris
- Hensley, Dannie A, Smale, Malcolm J, J.L.B. Smith Institute of Ichthyology
- Authors: Hensley, Dannie A , Smale, Malcolm J , J.L.B. Smith Institute of Ichthyology
- Date: 1997-12
- Subjects: Fishes -- Indian Ocean , Flatfishes -- Indian Ocean
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10962/70987 , vital:29768 , Margaret Smith Library (South African Institute for Aquatic Biodiversity (SAIAB)) Periodicals Margaret Smith Library (South African Institute for Aquatic Biodiversity (SAIAB))
- Description: Online version of original print edition of the Special Publication of the J.L.B. Smith Institute of Ichthyology; No. 59 , Six species of the genus Chascanopsetta are currently recognized. Recent work on otolith morphology from specimens identified as C. lugubris raised the possibility that three forms of C. lugubris are found in the western Indian Ocean. Re-examination of the voucher specimens showed that one of these forms is a new species, C. kenyaensis, from Kenya and Somalia. The other two forms may show differences in otolith morphology due to ontogeny. The new species most closely resembles C. prorigera from the Hawaiian Archipelago, Emperor Seamounts, and the western North Atlantic. These two species differ in lateral-line scale counts, body depth, upper-jaw length, and coloration. Many comparative specimens of C. lugubris were examined. It was found that this species’ distribution rounds the Cape of Good Hope from the southwestern Indian Ocean into the southeastern Atlantic. Specimens from this southern African region show higher dorsal- and anal-fin ray counts than those from more northern areas in the Atlantic, western Pacific, and Indian oceans. There is some indication that what some authors refer to as the Indo-West Pacific subspecies C. lugubris lugubris rounds the Cape of Good Hope and also occurs in parts of the eastern Atlantic. A more thorough comparison of C. lugubris from different regions is needed.
- Full Text:
- Date Issued: 1997-12
- Authors: Hensley, Dannie A , Smale, Malcolm J , J.L.B. Smith Institute of Ichthyology
- Date: 1997-12
- Subjects: Fishes -- Indian Ocean , Flatfishes -- Indian Ocean
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10962/70987 , vital:29768 , Margaret Smith Library (South African Institute for Aquatic Biodiversity (SAIAB)) Periodicals Margaret Smith Library (South African Institute for Aquatic Biodiversity (SAIAB))
- Description: Online version of original print edition of the Special Publication of the J.L.B. Smith Institute of Ichthyology; No. 59 , Six species of the genus Chascanopsetta are currently recognized. Recent work on otolith morphology from specimens identified as C. lugubris raised the possibility that three forms of C. lugubris are found in the western Indian Ocean. Re-examination of the voucher specimens showed that one of these forms is a new species, C. kenyaensis, from Kenya and Somalia. The other two forms may show differences in otolith morphology due to ontogeny. The new species most closely resembles C. prorigera from the Hawaiian Archipelago, Emperor Seamounts, and the western North Atlantic. These two species differ in lateral-line scale counts, body depth, upper-jaw length, and coloration. Many comparative specimens of C. lugubris were examined. It was found that this species’ distribution rounds the Cape of Good Hope from the southwestern Indian Ocean into the southeastern Atlantic. Specimens from this southern African region show higher dorsal- and anal-fin ray counts than those from more northern areas in the Atlantic, western Pacific, and Indian oceans. There is some indication that what some authors refer to as the Indo-West Pacific subspecies C. lugubris lugubris rounds the Cape of Good Hope and also occurs in parts of the eastern Atlantic. A more thorough comparison of C. lugubris from different regions is needed.
- Full Text:
- Date Issued: 1997-12
A new species of Bothus (Pleuronectiformes: Bothidae) from Mozambique
- Hensley, Dannie A, J.L.B. Smith Institute of Ichthyology
- Authors: Hensley, Dannie A , J.L.B. Smith Institute of Ichthyology
- Date: 1997-02
- Subjects: Fishes -- Mozambique
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10962/70976 , vital:29767 , Margaret Smith Library (South African Institute for Aquatic Biodiversity (SAIAB)) Periodicals Margaret Smith Library (South African Institute for Aquatic Biodiversity (SAIAB))
- Description: Online version of original print edition of the Special Publication of the J.L.B. Smith Institute of Ichthyology; No. 58 , Bothus swio is described based on one adult male specimen collected off the coast of Mozambique. Males of this species appear to differ from all known congeners because of their narrow interobital region. Other characters useful for its identification are lack of ocular appendages, relative positions of the anterior margins of the eyes, number of lateral-line scales, length and colour pattern of the ocular-side pectoral fin, lack of orbital spines, dorsal- and anal-fin ray counts, and lack of colour pattern on the blind side. Bothus swio most closely resembles B. pantherinus and B. tricirrhitus.
- Full Text:
- Date Issued: 1997-02
- Authors: Hensley, Dannie A , J.L.B. Smith Institute of Ichthyology
- Date: 1997-02
- Subjects: Fishes -- Mozambique
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10962/70976 , vital:29767 , Margaret Smith Library (South African Institute for Aquatic Biodiversity (SAIAB)) Periodicals Margaret Smith Library (South African Institute for Aquatic Biodiversity (SAIAB))
- Description: Online version of original print edition of the Special Publication of the J.L.B. Smith Institute of Ichthyology; No. 58 , Bothus swio is described based on one adult male specimen collected off the coast of Mozambique. Males of this species appear to differ from all known congeners because of their narrow interobital region. Other characters useful for its identification are lack of ocular appendages, relative positions of the anterior margins of the eyes, number of lateral-line scales, length and colour pattern of the ocular-side pectoral fin, lack of orbital spines, dorsal- and anal-fin ray counts, and lack of colour pattern on the blind side. Bothus swio most closely resembles B. pantherinus and B. tricirrhitus.
- Full Text:
- Date Issued: 1997-02
"My life in the new South Africa": a youth perspective
- Leggett, Ted, Moller, Valerie, Richards, Robin
- Authors: Leggett, Ted , Moller, Valerie , Richards, Robin
- Date: 1997
- Subjects: Quality of life -- South Africa
- Language: English
- Type: Text
- Identifier: vital:538 , http://hdl.handle.net/10962/d1010393
- Description: The young people of South Africa hold the future of society in their hands. They will become the new leaders who will make or break South Africa's fledgling democracy. Of course, it is impossible to know how society will fare in the millennium; but knowledge of where the youth think their lives and their country are heading will provide some clues to what the future holds. The research for this book was inspired by the "Monitoring the future" project, a regular survey of young people's values and aspirations by the Institute of Social Research at the University of Michigan. Our research was informed by recent comprehensive inquiries on the youth conducted by the Human Sciences Research Council (HSRC) Co-operative Research Programme on South African Youth and the research by the Joint Enrichment Programme and the Community Agency for Social Enquiry (CASE). The present study also builds on more focused research on leisure, educational aspirations and quality of life conducted by researchers attached to the University of Natal's Quality of Life Research Unit. The evidence for the two large-scale inquiries and the quality of life studies was collected before South Africa's first open general elections. The material presented in this book is about young people who have experience of living under the new democracy. This report may be among the first to inform the newly formed National Youth Commission of young people's needs and aspirations. Urgently needed for planning and policy formation is a systematic programme of research into the evolving situation of South African youth under the new political dispensation. Until such time as the values and lifestyles of young people are monitored at regular intervals, ad hoc studies such as the one reported here may help to fill the gap. It is hoped that the views of young people expressed in this book will deepen our understanding of young people's expectations and aspirations for the future. My life in the New South Africa provides a snapshot of society two years after the first open general elections as seen through the lenses of the youth. The book, which was written by the young people themselves, documents contemporary everyday life and hopes and fears for the future as envisaged by the youth. The material was gathered through an innovative research project which aimed to learn how young people see themselves and their society two years into the new democracy. Over 900 of the youth gave descriptions of "my life in the New South Africa" in the first half of 1996 in response to a letter writing competition designed by the Quality of Life Research Unit at the University of Natal. The competition fits the currently fashionable genre of "participatory" research, in which subjects double as analysts of their life situation. Although a fairly recent addition to the South African research repertoire, the participatory method is not unfamiliar to quality of life researchers. For many years, students of quality of life have advocated that ordinary people and not the external experts are the best judges of what makes people's lives satisfactory or not. Working in this research tradition, the Quality of Life research team at the University of Natal took on the task of shaping a book around the issues addressed by the youth in their letters. The material produced by the letter writing competition was content-analysed by a team of experts and organised in a number of thematic chapters which cover many of the dominant concerns of contemporary youth. Essentially, the youth wrote the script and the researchers did the editing. The mood of the letters is overwhelmingly positive and inspiring for a new democracy intent on overcoming the shortcomings of the past. Energy, youthful optimism and good intentions radiate from the letters. There is no doubt that My life in the New South Africa will provide useful pointers for current policy formation. It is hoped that the contents of this book will also serve as benchmark information against which South African society will be able to measure itself in years to come. The majority of the young people who entered the competition fervently believe, or at least wish to believe, that their hopes for an ideal society in which all South Africans live in harmony will be realised. Their idealism is as refreshing and touching in its naivetέ as it is sobering. The youth who wrote to the Quality of Life research team, boldly outline the challenges that lie ahead for a new democracy. Time will tell if the hopes and fears of contemporary youth can be laid to rest and their dreams for the future fulfilled. South Africa owes it to the next generation that its young people not be disappointed.
- Full Text:
- Date Issued: 1997
- Authors: Leggett, Ted , Moller, Valerie , Richards, Robin
- Date: 1997
- Subjects: Quality of life -- South Africa
- Language: English
- Type: Text
- Identifier: vital:538 , http://hdl.handle.net/10962/d1010393
- Description: The young people of South Africa hold the future of society in their hands. They will become the new leaders who will make or break South Africa's fledgling democracy. Of course, it is impossible to know how society will fare in the millennium; but knowledge of where the youth think their lives and their country are heading will provide some clues to what the future holds. The research for this book was inspired by the "Monitoring the future" project, a regular survey of young people's values and aspirations by the Institute of Social Research at the University of Michigan. Our research was informed by recent comprehensive inquiries on the youth conducted by the Human Sciences Research Council (HSRC) Co-operative Research Programme on South African Youth and the research by the Joint Enrichment Programme and the Community Agency for Social Enquiry (CASE). The present study also builds on more focused research on leisure, educational aspirations and quality of life conducted by researchers attached to the University of Natal's Quality of Life Research Unit. The evidence for the two large-scale inquiries and the quality of life studies was collected before South Africa's first open general elections. The material presented in this book is about young people who have experience of living under the new democracy. This report may be among the first to inform the newly formed National Youth Commission of young people's needs and aspirations. Urgently needed for planning and policy formation is a systematic programme of research into the evolving situation of South African youth under the new political dispensation. Until such time as the values and lifestyles of young people are monitored at regular intervals, ad hoc studies such as the one reported here may help to fill the gap. It is hoped that the views of young people expressed in this book will deepen our understanding of young people's expectations and aspirations for the future. My life in the New South Africa provides a snapshot of society two years after the first open general elections as seen through the lenses of the youth. The book, which was written by the young people themselves, documents contemporary everyday life and hopes and fears for the future as envisaged by the youth. The material was gathered through an innovative research project which aimed to learn how young people see themselves and their society two years into the new democracy. Over 900 of the youth gave descriptions of "my life in the New South Africa" in the first half of 1996 in response to a letter writing competition designed by the Quality of Life Research Unit at the University of Natal. The competition fits the currently fashionable genre of "participatory" research, in which subjects double as analysts of their life situation. Although a fairly recent addition to the South African research repertoire, the participatory method is not unfamiliar to quality of life researchers. For many years, students of quality of life have advocated that ordinary people and not the external experts are the best judges of what makes people's lives satisfactory or not. Working in this research tradition, the Quality of Life research team at the University of Natal took on the task of shaping a book around the issues addressed by the youth in their letters. The material produced by the letter writing competition was content-analysed by a team of experts and organised in a number of thematic chapters which cover many of the dominant concerns of contemporary youth. Essentially, the youth wrote the script and the researchers did the editing. The mood of the letters is overwhelmingly positive and inspiring for a new democracy intent on overcoming the shortcomings of the past. Energy, youthful optimism and good intentions radiate from the letters. There is no doubt that My life in the New South Africa will provide useful pointers for current policy formation. It is hoped that the contents of this book will also serve as benchmark information against which South African society will be able to measure itself in years to come. The majority of the young people who entered the competition fervently believe, or at least wish to believe, that their hopes for an ideal society in which all South Africans live in harmony will be realised. Their idealism is as refreshing and touching in its naivetέ as it is sobering. The youth who wrote to the Quality of Life research team, boldly outline the challenges that lie ahead for a new democracy. Time will tell if the hopes and fears of contemporary youth can be laid to rest and their dreams for the future fulfilled. South Africa owes it to the next generation that its young people not be disappointed.
- Full Text:
- Date Issued: 1997
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.
- Full Text:
- Date Issued: 1997
- 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.
- Full Text:
- 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.
- Full Text:
- Date Issued: 1997
- 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.
- Full Text:
- 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.
- Full Text:
- Date Issued: 1997
- 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.
- Full Text:
- 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.
- Full Text:
- Date Issued: 1997
- 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.
- Full Text:
- 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.
- Full Text:
- Date Issued: 1997
- 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.
- Full Text:
- 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.
- Full Text:
- Date Issued: 1997
- 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.
- Full Text:
- Date Issued: 1997
A description of gametogenesis in the panga Pterogymnus laniarius (Pisces: Sparidae) with comments on changes in maturity patterns over the past two decades
- Booth, Anthony J, Hecht, Thomas
- Authors: Booth, Anthony J , Hecht, Thomas
- Date: 1997
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/446930 , vital:74571 , https://www.ajol.info/index.php/az/article/view/154565
- Description: A description of gametogenesis in the panga Pferogymnus laniarius, a common endemic seabream species inhabiting the Agulhas Bank, South Africa, is presented. After sexual maturity, oogenesis and spermatogenesis continued throughout the year and were found to be similar to these processes in other seabream species and teleosts in general. Analysis of maturity data over the past two decades revealed a significant change in both age and size-at-maturity, a response to fishing pressure.
- Full Text:
- Date Issued: 1997
- Authors: Booth, Anthony J , Hecht, Thomas
- Date: 1997
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/446930 , vital:74571 , https://www.ajol.info/index.php/az/article/view/154565
- Description: A description of gametogenesis in the panga Pferogymnus laniarius, a common endemic seabream species inhabiting the Agulhas Bank, South Africa, is presented. After sexual maturity, oogenesis and spermatogenesis continued throughout the year and were found to be similar to these processes in other seabream species and teleosts in general. Analysis of maturity data over the past two decades revealed a significant change in both age and size-at-maturity, a response to fishing pressure.
- Full Text:
- Date Issued: 1997
A liberal journal for a conservative estimate
- COSATU
- Authors: COSATU
- Date: 1997
- Language: English
- Type: text
- Identifier: http://hdl.handle.net/10962/139694 , vital:37769
- Description: AIDS starts with a virus. Like all viruses, it’s a parasite fragile and impotent. It cannot reproduce except within human cells, It’s tiny. Over 500,000,000 HIV viruses could fit the dot on top of this i. In the wrong environment HIV dies. In the right environment, it dominates. AIDS is dominating South Africa with all ready 2.4 million people infected, with estimates of 20% of the working population being infected within four years. South Africa has willingly opened itself to domination. This time, not colonial political oppression or the cruelty of racial apartheid, but domination by a virus all of us saw coming. The Ministry of Health welcomed the virus by failing to impart a practical and realistic National AIDS strategy. Instead, entertaining us with a R14.3 million play called Sarafina 2 and a discredited new cure for AIDS Virodene.
- Full Text:
- Date Issued: 1997
- Authors: COSATU
- Date: 1997
- Language: English
- Type: text
- Identifier: http://hdl.handle.net/10962/139694 , vital:37769
- Description: AIDS starts with a virus. Like all viruses, it’s a parasite fragile and impotent. It cannot reproduce except within human cells, It’s tiny. Over 500,000,000 HIV viruses could fit the dot on top of this i. In the wrong environment HIV dies. In the right environment, it dominates. AIDS is dominating South Africa with all ready 2.4 million people infected, with estimates of 20% of the working population being infected within four years. South Africa has willingly opened itself to domination. This time, not colonial political oppression or the cruelty of racial apartheid, but domination by a virus all of us saw coming. The Ministry of Health welcomed the virus by failing to impart a practical and realistic National AIDS strategy. Instead, entertaining us with a R14.3 million play called Sarafina 2 and a discredited new cure for AIDS Virodene.
- Full Text:
- 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.
- Full Text:
- Date Issued: 1997
- 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.
- Full Text:
- 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.
- Full Text:
- Date Issued: 1997
- 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.
- Full Text:
- 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.
- Full Text:
- Date Issued: 1997
- 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.
- Full Text:
- 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.
- Full Text:
- Date Issued: 1997
- 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.
- Full Text:
- 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.
- Full Text:
- Date Issued: 1997
- 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.
- Full Text:
- Date Issued: 1997