Issues in contemporary geographical hydrology
- Authors: Hughes, Denis A
- Date: 2002
- Language: English
- Type: text , Article
- Identifier: vital:7083 , http://hdl.handle.net/10962/d1012340
- Description: Finding solutions to the many water resource utilisation problems that face South Africa has been the driving force behind a large part of the hydrological research that has been undertaken in the country. Any review of the methodology and past or present issues of hydrology in South Africa would find it difficult to distinguish between those that are part of engineering hydrology, and those that are part of geographical hydrology. Both have a great deal to contribute to solving the water resource management problems of South Africa and these contributions should be made in a co-operative framework. As will be demonstrated in the paper, the changing face of South Africa and the requirements of managing water in a transformed, democratic society have made the need for co-operation across various disciplines even more essential.
- Full Text: false
- Authors: Hughes, Denis A
- Date: 2002
- Language: English
- Type: text , Article
- Identifier: vital:7083 , http://hdl.handle.net/10962/d1012340
- Description: Finding solutions to the many water resource utilisation problems that face South Africa has been the driving force behind a large part of the hydrological research that has been undertaken in the country. Any review of the methodology and past or present issues of hydrology in South Africa would find it difficult to distinguish between those that are part of engineering hydrology, and those that are part of geographical hydrology. Both have a great deal to contribute to solving the water resource management problems of South Africa and these contributions should be made in a co-operative framework. As will be demonstrated in the paper, the changing face of South Africa and the requirements of managing water in a transformed, democratic society have made the need for co-operation across various disciplines even more essential.
- Full Text: false
John Jolly : the Grahamstown bell founder
- Authors: Lewis, Colin A
- Date: 2002
- Language: English
- Type: Article
- Identifier: vital:6173 , http://hdl.handle.net/10962/d1012364 , http://www.ringingworld.co.uk
- Description: Colin Lewis was Professor of Geography at Rhodes University, Grahamstown, South Africa from 1989 until his retirement at the end of 2007. In 1990, with the strong support of the incumbent Vice-Chancellor, Dr Derek Henderson, he instigated the Certificate in Change Ringing (Church Bell Ringing) in the Rhodes University Department of Music and Musicology - the first such course to be offered in Africa. Since that date he has lectured in the basic theory, and taught the practice of change ringing. He is the Ringing Master of the Cathedral of St Michael and St George, Grahamstown, South Africa.
- Full Text:
- Authors: Lewis, Colin A
- Date: 2002
- Language: English
- Type: Article
- Identifier: vital:6173 , http://hdl.handle.net/10962/d1012364 , http://www.ringingworld.co.uk
- Description: Colin Lewis was Professor of Geography at Rhodes University, Grahamstown, South Africa from 1989 until his retirement at the end of 2007. In 1990, with the strong support of the incumbent Vice-Chancellor, Dr Derek Henderson, he instigated the Certificate in Change Ringing (Church Bell Ringing) in the Rhodes University Department of Music and Musicology - the first such course to be offered in Africa. Since that date he has lectured in the basic theory, and taught the practice of change ringing. He is the Ringing Master of the Cathedral of St Michael and St George, Grahamstown, South Africa.
- Full Text:
Kariega Metaphors
- Authors: Mann, Chris
- Date: 2002
- Subjects: To be catalogued
- Language: English
- Type: text , poem
- Identifier: http://hdl.handle.net/10962/468840 , vital:77133 , ISBN 0028-4459 , https://journals.co.za/doi/epdf/10.10520/AJA00284459_642
- Description: New Coin is one of South Africa's most established and influential poetry journals. It publishes poetry, and poetry-related reviews, commentary and interviews. New Coin places a particular emphasis on evolving forms and experimental use of the English language in poetry in the South African context. In this sense it has traced the most exciting trends and currents in contemporary poetry in South Africa for a decade of more. The journal is published twice a year in June and December by the Institute for the Study of English in Africa (ISEA), Rhodes University.
- Full Text:
- Authors: Mann, Chris
- Date: 2002
- Subjects: To be catalogued
- Language: English
- Type: text , poem
- Identifier: http://hdl.handle.net/10962/468840 , vital:77133 , ISBN 0028-4459 , https://journals.co.za/doi/epdf/10.10520/AJA00284459_642
- Description: New Coin is one of South Africa's most established and influential poetry journals. It publishes poetry, and poetry-related reviews, commentary and interviews. New Coin places a particular emphasis on evolving forms and experimental use of the English language in poetry in the South African context. In this sense it has traced the most exciting trends and currents in contemporary poetry in South Africa for a decade of more. The journal is published twice a year in June and December by the Institute for the Study of English in Africa (ISEA), Rhodes University.
- Full Text:
Knowledge on Sclerocarya birrea subsp. caffra with emphasis on its importance as a non-timber forest product in South and southern Africa, a summary: Part 1 Taxonomy, ecology and role in rural livelihoods
- Shackleton, Sheona E, Shackleton, Charlie M, Cunningham, Tony, Lombard, Cyril, Sullivan, Caroline A, Netshiluvhi, Thiambi
- Authors: Shackleton, Sheona E , Shackleton, Charlie M , Cunningham, Tony , Lombard, Cyril , Sullivan, Caroline A , Netshiluvhi, Thiambi
- Date: 2002
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/182251 , vital:43815 , xlink:href="https://doi.org/10.1080/20702620.2002.10434589"
- Description: Sclerocarya birrea (marula) is a widespread species throughout the semi-arid, deciduous savannas of much of sub-Saharan Africa. It is widely used by rural populations in most countries in which it is found. It has multiple uses, including the fruits, kernels, oil, bark, wood and leaves. Because of these multiple uses, and its significance in the landscape, several African cultures have specific beliefs and ceremonies associated with this species, and it is often maintained in homestead and arable plots. Because of the widespread occurrence, potentially high fruit production and use of S. birrea it has frequently been identified as a key species to support the development of rural enterprises based on the fruit, beer, oil or nuts and therefore as a species for potential domestication. Localised breeding and cultivation initiatives commenced in the 1970s and some continue. Interest in this species was renewed after the development of a highly successful liqueur using extracts from the fruit. This has developed further in southern Africa over the last 3 to 5 years, especially commercialisation initiatives orientated towards befitting the rural poor. Recently, the UK Department for International Development (DFID) initiated a project to examine the impacts of commercialisation of non-timber forest products, such as marula, on the livelihood capital of the rural poor. As a first phase, the research team compiled a comprehensive literature review of S. birrea, with emphasis on possible commercialisation. This is to be published in two parts. The first part deals with the taxonomy, ecology and its subsistence use and cultural value to rural households. The second part of the review will focus on issues relating to specific properties of the marula, management, intellectual property and its potential commercialisation.
- Full Text:
- Authors: Shackleton, Sheona E , Shackleton, Charlie M , Cunningham, Tony , Lombard, Cyril , Sullivan, Caroline A , Netshiluvhi, Thiambi
- Date: 2002
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/182251 , vital:43815 , xlink:href="https://doi.org/10.1080/20702620.2002.10434589"
- Description: Sclerocarya birrea (marula) is a widespread species throughout the semi-arid, deciduous savannas of much of sub-Saharan Africa. It is widely used by rural populations in most countries in which it is found. It has multiple uses, including the fruits, kernels, oil, bark, wood and leaves. Because of these multiple uses, and its significance in the landscape, several African cultures have specific beliefs and ceremonies associated with this species, and it is often maintained in homestead and arable plots. Because of the widespread occurrence, potentially high fruit production and use of S. birrea it has frequently been identified as a key species to support the development of rural enterprises based on the fruit, beer, oil or nuts and therefore as a species for potential domestication. Localised breeding and cultivation initiatives commenced in the 1970s and some continue. Interest in this species was renewed after the development of a highly successful liqueur using extracts from the fruit. This has developed further in southern Africa over the last 3 to 5 years, especially commercialisation initiatives orientated towards befitting the rural poor. Recently, the UK Department for International Development (DFID) initiated a project to examine the impacts of commercialisation of non-timber forest products, such as marula, on the livelihood capital of the rural poor. As a first phase, the research team compiled a comprehensive literature review of S. birrea, with emphasis on possible commercialisation. This is to be published in two parts. The first part deals with the taxonomy, ecology and its subsistence use and cultural value to rural households. The second part of the review will focus on issues relating to specific properties of the marula, management, intellectual property and its potential commercialisation.
- Full Text:
Language as a ‘resource’ in South Africa: the economic life of language in a globalising society
- Authors: Wright, Laurence
- Date: 2002
- Language: English
- Type: text , article
- Identifier: vital:7035 , http://hdl.handle.net/10962/d1007370 , https://doi.org/10.1080/10131750285310031
- Description: preprint , We need to develop a much more refined and specific understanding of what is meant when people refer to language is a ‘resource’. If something can accurately be described as a resource, then by its very nature it carries with it or attracts, at least in potential, the social motivation associated with the utilization, development or exploitation of that resource. This is strikingly true where language is the resource in question, because language is so intimately bound up with human activity. Where it exists, such social motivation can be augmented and supported so as to realize the ends of language policy. Contrastingly, where it is seen that social motivation informing a particular language situation is at odds with the intent of language policy, then either implementation must retreat and move to other arenas, other points of influence, where intervention can be more effective, or those charged with implementation must resign themselves to costly and messy efforts to force unwanted change through legal authority.
- Full Text:
- Authors: Wright, Laurence
- Date: 2002
- Language: English
- Type: text , article
- Identifier: vital:7035 , http://hdl.handle.net/10962/d1007370 , https://doi.org/10.1080/10131750285310031
- Description: preprint , We need to develop a much more refined and specific understanding of what is meant when people refer to language is a ‘resource’. If something can accurately be described as a resource, then by its very nature it carries with it or attracts, at least in potential, the social motivation associated with the utilization, development or exploitation of that resource. This is strikingly true where language is the resource in question, because language is so intimately bound up with human activity. Where it exists, such social motivation can be augmented and supported so as to realize the ends of language policy. Contrastingly, where it is seen that social motivation informing a particular language situation is at odds with the intent of language policy, then either implementation must retreat and move to other arenas, other points of influence, where intervention can be more effective, or those charged with implementation must resign themselves to costly and messy efforts to force unwanted change through legal authority.
- Full Text:
Leaders' and participants' perceptions of the management of the Life Science Project in Namibia
- Authors: Kirkegaard, Niels Hugo
- Date: 2002
- Subjects: Life Science Project (Namibia) Educational leadership Educational leadership -- Namibia School management and organization School management and organization -- Namibia
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1662 , http://hdl.handle.net/10962/d1003545
- Description: After Independence in 1991, Namibia embarked on implementing a new and different educational system. This system was seen as a radical departure from the old apartheid system. The Namibian government approached Ibis, a Danish NGO, to support the change process by establishing and developing a new subject, life science, in Junior Secondary schools in Namibia through the Life Science Project (LSP). In a project of this nature, where a foreign (Danish) educational intervention in a relatively young and new democracy is the issue, cross-cultural aspects are likely to emerge, and these are the focus of this study. This half-thesis is an attempt to illuminate, not to evaluate, managerial as well as cross-cultural features of the project based on perceptions of selected Danish managers and Namibian advisory teachers from the former LSP expressed in the goal of the research: - To explore selected leaders’ and participants’ perception of the management of the Life Science Project. In line with this goal, I elected to conduct the research in the interpretive paradigm, using unstructured interviews as my chief source of data. The findings illuminate what would appear to be an inconsistency in the management of the project. The project seemed to be able to accommodate regional and even personal differences and to be flexible to internal changes. At the same time it appears that in its relationship to the external or task environment it did not show the same openness and flexibility to accommodate diversity. It is suggested that this could be a result of the apparent failure on the part of the project to clarify its own underlying values. The study also reveals interesting and unexpected perceptions of leadership, which may also be interpreted in terms of cultural values and beliefs. These two features of managerial issues could lead one to reflect upon the importance of recognising values in organisations which work across cultures.
- Full Text:
- Authors: Kirkegaard, Niels Hugo
- Date: 2002
- Subjects: Life Science Project (Namibia) Educational leadership Educational leadership -- Namibia School management and organization School management and organization -- Namibia
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1662 , http://hdl.handle.net/10962/d1003545
- Description: After Independence in 1991, Namibia embarked on implementing a new and different educational system. This system was seen as a radical departure from the old apartheid system. The Namibian government approached Ibis, a Danish NGO, to support the change process by establishing and developing a new subject, life science, in Junior Secondary schools in Namibia through the Life Science Project (LSP). In a project of this nature, where a foreign (Danish) educational intervention in a relatively young and new democracy is the issue, cross-cultural aspects are likely to emerge, and these are the focus of this study. This half-thesis is an attempt to illuminate, not to evaluate, managerial as well as cross-cultural features of the project based on perceptions of selected Danish managers and Namibian advisory teachers from the former LSP expressed in the goal of the research: - To explore selected leaders’ and participants’ perception of the management of the Life Science Project. In line with this goal, I elected to conduct the research in the interpretive paradigm, using unstructured interviews as my chief source of data. The findings illuminate what would appear to be an inconsistency in the management of the project. The project seemed to be able to accommodate regional and even personal differences and to be flexible to internal changes. At the same time it appears that in its relationship to the external or task environment it did not show the same openness and flexibility to accommodate diversity. It is suggested that this could be a result of the apparent failure on the part of the project to clarify its own underlying values. The study also reveals interesting and unexpected perceptions of leadership, which may also be interpreted in terms of cultural values and beliefs. These two features of managerial issues could lead one to reflect upon the importance of recognising values in organisations which work across cultures.
- Full Text:
Magma flow inferred from AMS fabrics in a layered mafic sill, Insizwa, South Africa
- Ferré, Eric C, Bordarier, Cecile, Marsh, Julian S
- Authors: Ferré, Eric C , Bordarier, Cecile , Marsh, Julian S
- Date: 2002
- Language: English
- Type: Article
- Identifier: vital:6733 , http://hdl.handle.net/10962/d1007543
- Description: The Insizwa sill, is a 25-km-diameter, >1000-m-thick layered mafic intrusion, part of the Karoo Igneous Province in South Africa. The peridotitic and gabbronoritic rocks are undeformed and mineral fabrics demonstrably result from magma flow. A horizontal, centimeter-scale model layering is visible in numerous outcrops. Plagioclase crystals are both tabular and elongated. Their preferred orientation, parallel to the layering, forms a foliation and a NW–SE lineation, respectively interpreted as the magma flow plane and flow direction. Throughout the 78 stations of this study (699 specimens), magnetic susceptibilities (K[subscript m]) range from 750 to 10,000×10[superscript (−6)] SI. The magnetic anisotropy (P[subscript j]) ranges from 1.03 to 1.08. Magnetic ellipsoids are both prolate and oblate (average T[subscript j]≈0). Anisotropy of magnetic susceptibility (AMS) fabrics are dominated by multidomain to pseudo-single domain magnetite. High-field magnetic experiments indicate that the paramagnetic contribution from the mafic silicates is less than 50 percentage for low susceptibility rock types. The anisotropy results from magnetite grain shape solely as shown by no significant increase in P[subscript j] with increasing K[subscript m]. The magnetic lineation (305°, 05°) is consistent throughout the sill at various scales and coincides with the mineral lineation in average. In contrast, the magnetic foliation (125° NE 10°) is generally perpendicular to the mineral foliation and to the layering. Several explanations for this odd configuration are discussed. The variations of magnetic parameters across the layering and field observations point to a multiple injection. The magnetic lineation is consistent with the presence of a single feeder dike situated to the SE of the sill.
- Full Text:
- Authors: Ferré, Eric C , Bordarier, Cecile , Marsh, Julian S
- Date: 2002
- Language: English
- Type: Article
- Identifier: vital:6733 , http://hdl.handle.net/10962/d1007543
- Description: The Insizwa sill, is a 25-km-diameter, >1000-m-thick layered mafic intrusion, part of the Karoo Igneous Province in South Africa. The peridotitic and gabbronoritic rocks are undeformed and mineral fabrics demonstrably result from magma flow. A horizontal, centimeter-scale model layering is visible in numerous outcrops. Plagioclase crystals are both tabular and elongated. Their preferred orientation, parallel to the layering, forms a foliation and a NW–SE lineation, respectively interpreted as the magma flow plane and flow direction. Throughout the 78 stations of this study (699 specimens), magnetic susceptibilities (K[subscript m]) range from 750 to 10,000×10[superscript (−6)] SI. The magnetic anisotropy (P[subscript j]) ranges from 1.03 to 1.08. Magnetic ellipsoids are both prolate and oblate (average T[subscript j]≈0). Anisotropy of magnetic susceptibility (AMS) fabrics are dominated by multidomain to pseudo-single domain magnetite. High-field magnetic experiments indicate that the paramagnetic contribution from the mafic silicates is less than 50 percentage for low susceptibility rock types. The anisotropy results from magnetite grain shape solely as shown by no significant increase in P[subscript j] with increasing K[subscript m]. The magnetic lineation (305°, 05°) is consistent throughout the sill at various scales and coincides with the mineral lineation in average. In contrast, the magnetic foliation (125° NE 10°) is generally perpendicular to the mineral foliation and to the layering. Several explanations for this odd configuration are discussed. The variations of magnetic parameters across the layering and field observations point to a multiple injection. The magnetic lineation is consistent with the presence of a single feeder dike situated to the SE of the sill.
- Full Text:
Maybe the courts are not such a Bleak House after all - or please sir, I want some more copyright
- Authors: Glover, Graham B
- Date: 2002
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/70841 , vital:29749 , https://heinonline.org/HOL/P?h=hein.journals/soaf119&i=101
- Description: In our advanced technological age the law of copyright faces tremendous challenges. In particular, the Internet has created serious problems for those who wish to enforce their proprietary rights, and to protect their textual (and other) creations from unregulated and uninhibited reproduction.
- Full Text: false
- Authors: Glover, Graham B
- Date: 2002
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/70841 , vital:29749 , https://heinonline.org/HOL/P?h=hein.journals/soaf119&i=101
- Description: In our advanced technological age the law of copyright faces tremendous challenges. In particular, the Internet has created serious problems for those who wish to enforce their proprietary rights, and to protect their textual (and other) creations from unregulated and uninhibited reproduction.
- Full Text: false
Melatonin protects against copper‐mediated free radical damage
- Parmar, Paresh, Limson, Janice L, Nyokong, Tebello, Daya, Santy
- Authors: Parmar, Paresh , Limson, Janice L , Nyokong, Tebello , Daya, Santy
- Date: 2002
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/289617 , vital:56654 , xlink:href=" https://doi.org/10.1034/j.1600-079X.2002.01859.x"
- Description: Copper is an essential trace element which forms an integral component of many enzymes. While trace amounts of copper are needed to sustain life, excess copper is extremely toxic. Copper has been implicated in various neurodegenerative disorders, such as Wilson's and Alzheimer's diseases. Previous studies showed that melatonin, the principle secretory product of the pineal gland, binds Cupric chloride (Cu2+) and that this may have implications in copper-induced neurodegenerative diseases. In the present study, in vitro copper-mediated lipid peroxidation was induced. Melatonin (5 mM) protected against copper-mediated lipid peroxidation in liver homogenates. Electron micrographs of in vivo administered Cu2+ and melatonin show that melatonin affords some protection to rat hepatocytes in the presence of copper. Electrochemical studies performed show that melatonin, in addition to binding Cu2+, may provide protection against copper-mediated free radical damage by binding Cu1+. The findings of these studies provide further evidence for the neuroprotective role of melatonin.
- Full Text:
- Authors: Parmar, Paresh , Limson, Janice L , Nyokong, Tebello , Daya, Santy
- Date: 2002
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/289617 , vital:56654 , xlink:href=" https://doi.org/10.1034/j.1600-079X.2002.01859.x"
- Description: Copper is an essential trace element which forms an integral component of many enzymes. While trace amounts of copper are needed to sustain life, excess copper is extremely toxic. Copper has been implicated in various neurodegenerative disorders, such as Wilson's and Alzheimer's diseases. Previous studies showed that melatonin, the principle secretory product of the pineal gland, binds Cupric chloride (Cu2+) and that this may have implications in copper-induced neurodegenerative diseases. In the present study, in vitro copper-mediated lipid peroxidation was induced. Melatonin (5 mM) protected against copper-mediated lipid peroxidation in liver homogenates. Electron micrographs of in vivo administered Cu2+ and melatonin show that melatonin affords some protection to rat hepatocytes in the presence of copper. Electrochemical studies performed show that melatonin, in addition to binding Cu2+, may provide protection against copper-mediated free radical damage by binding Cu1+. The findings of these studies provide further evidence for the neuroprotective role of melatonin.
- Full Text:
Mental illness and the consciousness of freedom: the phenomenology of psychiatric labelling
- Authors: Bradfield, Bruce
- Date: 2002
- Language: English
- Type: Article
- Identifier: vital:6264 , http://hdl.handle.net/10962/d1007882
- Description: Paradigmatically led by existential phenomenological premises, as formulated by Jean-Paul Sartre and Edmund Husserl specifically, this paper aims at a deconstruction of the value of psychiatric labelling in terms of the implications of such labelling for the labelled individual's experience of freedom as a conscious imperative. This work has as its intention the destabilisation of labelling as a stubborn and inexorable mechanism for social propriety and regularity, which in its unyielding classificatory brandings is.
- Full Text:
- Authors: Bradfield, Bruce
- Date: 2002
- Language: English
- Type: Article
- Identifier: vital:6264 , http://hdl.handle.net/10962/d1007882
- Description: Paradigmatically led by existential phenomenological premises, as formulated by Jean-Paul Sartre and Edmund Husserl specifically, this paper aims at a deconstruction of the value of psychiatric labelling in terms of the implications of such labelling for the labelled individual's experience of freedom as a conscious imperative. This work has as its intention the destabilisation of labelling as a stubborn and inexorable mechanism for social propriety and regularity, which in its unyielding classificatory brandings is.
- Full Text:
Metabolic responses to various combinations of gradient, load and marching speed
- Todd, Andrew I, Scott, Patricia A
- Authors: Todd, Andrew I , Scott, Patricia A
- Date: 2002
- Language: English
- Type: Article
- Identifier: vital:6751 , http://hdl.handle.net/10962/d1009331
- Description: This study examined the metabolic cost of South African soldiers carrying loads under various conditions of gradient and marching speed. Thirty-two male soldiers participated in the study. Three speed and load combinations, 4, 5 and 6 km.h[superscript (-1)] carrying of 50, 35 and 20 kg respectively, were imposed, on each of three gradients: -10%, 0% and +10%; a total of nine experimental conditions. Subjects wore standardized military uniforms and breathed into a portable ergospirometer (Metamax) for the duration of each condition. Subjects were required to march for six minutes under each condition, and metabolic responses were monitored during the third and sixth minute of each condition. The metabolic responses to the three level marching conditions showed no significant differences. Marching uphill resulted in a significant increase in metabolic demands under all three speed and load onditions. Downhill marching elicited significant decreases only under the two lighter load conditions. Downhill marching with heavy loads appears to show no reduction in metabolic demands placed on soldiers.
- Full Text:
- Authors: Todd, Andrew I , Scott, Patricia A
- Date: 2002
- Language: English
- Type: Article
- Identifier: vital:6751 , http://hdl.handle.net/10962/d1009331
- Description: This study examined the metabolic cost of South African soldiers carrying loads under various conditions of gradient and marching speed. Thirty-two male soldiers participated in the study. Three speed and load combinations, 4, 5 and 6 km.h[superscript (-1)] carrying of 50, 35 and 20 kg respectively, were imposed, on each of three gradients: -10%, 0% and +10%; a total of nine experimental conditions. Subjects wore standardized military uniforms and breathed into a portable ergospirometer (Metamax) for the duration of each condition. Subjects were required to march for six minutes under each condition, and metabolic responses were monitored during the third and sixth minute of each condition. The metabolic responses to the three level marching conditions showed no significant differences. Marching uphill resulted in a significant increase in metabolic demands under all three speed and load onditions. Downhill marching elicited significant decreases only under the two lighter load conditions. Downhill marching with heavy loads appears to show no reduction in metabolic demands placed on soldiers.
- Full Text:
Minding the gaps – an investigation into language policy and practice in four Eastern Cape districts
- Probyn, Margie J, Murray, Sarah R, Botha, Liz, Botya, Paula, Brookes, Margaret A, Westphal, Vivian
- Authors: Probyn, Margie J , Murray, Sarah R , Botha, Liz , Botya, Paula , Brookes, Margaret A , Westphal, Vivian
- Date: 2002
- Language: English
- Type: Article
- Identifier: vital:7024 , http://hdl.handle.net/10962/d1007206
- Description: South Africa's new Language in Education Policy (LiEP) has been described as one of the most progressive in the world but few schools have implemented it. This article describes research that investigates the gap between the policy goals and what is actually happening in schools in four districts in the Eastern Cape. The research attempts to make explicit community and school language practices and the factors that support or frustrate the formation and enactment of a school language policy in these four linguistically diverse sites. It appears that school governing bodies are not well equipped to make decisions about school language policy which meet the requirements of the national LiEP and economic imperatives to acquire English override considerations of multilingualism and additive bilingualism as expressed in the policy.
- Full Text:
Minding the gaps – an investigation into language policy and practice in four Eastern Cape districts
- Authors: Probyn, Margie J , Murray, Sarah R , Botha, Liz , Botya, Paula , Brookes, Margaret A , Westphal, Vivian
- Date: 2002
- Language: English
- Type: Article
- Identifier: vital:7024 , http://hdl.handle.net/10962/d1007206
- Description: South Africa's new Language in Education Policy (LiEP) has been described as one of the most progressive in the world but few schools have implemented it. This article describes research that investigates the gap between the policy goals and what is actually happening in schools in four districts in the Eastern Cape. The research attempts to make explicit community and school language practices and the factors that support or frustrate the formation and enactment of a school language policy in these four linguistically diverse sites. It appears that school governing bodies are not well equipped to make decisions about school language policy which meet the requirements of the national LiEP and economic imperatives to acquire English override considerations of multilingualism and additive bilingualism as expressed in the policy.
- Full Text:
mLAN-The Current Status and Future Directions
- Foss, Richard, Fujimori, J I
- Authors: Foss, Richard , Fujimori, J I
- Date: 2002
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/427431 , vital:72438 , https://www.aes.org/e-lib/browse.cfm?elib=11224
- Description: 'mLAN' describes a network that allows for the transmission and receipt of audio and music control data by audio devices. IEEE 1394 was chosen as the specification upon which to implement mLAN. mLAN has built on IEEE 1394 and related standards, introducing formats, structures, and procedures that enable the deployment of IEEE 1394 within a music studio context. This paper discusses these standards, their implementations, and provides pointers to the future evolution of mLAN.
- Full Text:
- Authors: Foss, Richard , Fujimori, J I
- Date: 2002
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/427431 , vital:72438 , https://www.aes.org/e-lib/browse.cfm?elib=11224
- Description: 'mLAN' describes a network that allows for the transmission and receipt of audio and music control data by audio devices. IEEE 1394 was chosen as the specification upon which to implement mLAN. mLAN has built on IEEE 1394 and related standards, introducing formats, structures, and procedures that enable the deployment of IEEE 1394 within a music studio context. This paper discusses these standards, their implementations, and provides pointers to the future evolution of mLAN.
- Full Text:
Modelling the distribution and abundance of several demersal fish species on the Agulhas Bank, South Africa
- Authors: Sampson, Mark Robert
- Date: 2002
- Subjects: Fishes -- South Africa -- Geographical distribution , Fishes -- South Africa -- Geographical distribution -- Mathematical models
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5343 , http://hdl.handle.net/10962/d1006207 , Fishes -- South Africa -- Geographical distribution , Fishes -- South Africa -- Geographical distribution -- Mathematical models
- Description: The Agulhas Bank supports a speciose fish community, many of which are commercially important. Despite substantial research being conducted on aspects of their biology spatial aspects of their distribution and abundance in relation to environment parameters has been ignored. This study, therefore, addressed aspects related to the distribution and abundance of representative species on the Agulhas Bank within a Geographic Information System (GIS). Four candidate species were chosen due to their importance either in numbers or unit mass to the South African demersal trawl fishery. The species also shared morphological and taxonomic similarities. The candidate species chosen were the two Cape hake species, shallow-water hake Meluccius capensis, and deep-water hake Merluccius paradoxus, and the two pleuronectiform species being Agulhas sole Austroglossus pectoralis and redspotted tonguesole Cynoglossus zanzibarensis. The use of a GIS was appropriate and allowed for hidden spatial patterns be exposed and illustrated visually, while also facilitating the quantification of the relationships between distribution/abundance and certain environmental predictors using statistical methods The Department of Marine and Coastal Management, Cape Town, supplied biological data in the form of length frequency and biomass information from spring (AprillMay) and autumn (September/October) cruises conducted between 1986 and 1993 on the R. V. Africana. The Council for National Geoscience, Cape Town, supplied sediment data for the entire southern African coastline. Initial exploratory data analysis highlighted potential relationships between environmental variables and abundance for each specie's life-history stanzas. Variations in spatial distribution were found to be significantly different between each life-history stanzas within species. Fish density as a function of the additive effects of the various environmental parameters, including temperature, depth and sediment type, was assessed using a Poisson Generalized Additive Model (GAM), while distribution was analysed with a logistic GAM. A predictive logistic model was then created, taking into consideration the importance of the predictor variables for each species, allowing for predictive estimates to be made for each species by inputting environmental information within the study area. The importance of certain environmental variables influencing distribution and abundance were noted. General patterns indicated that sediment was the most important to both the distribution and abundance of the two pleuronectiform species and juvenile life-history stanzas, while the adult gadoids' distribution and abundance appeared to be depth dependent.
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- Authors: Sampson, Mark Robert
- Date: 2002
- Subjects: Fishes -- South Africa -- Geographical distribution , Fishes -- South Africa -- Geographical distribution -- Mathematical models
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5343 , http://hdl.handle.net/10962/d1006207 , Fishes -- South Africa -- Geographical distribution , Fishes -- South Africa -- Geographical distribution -- Mathematical models
- Description: The Agulhas Bank supports a speciose fish community, many of which are commercially important. Despite substantial research being conducted on aspects of their biology spatial aspects of their distribution and abundance in relation to environment parameters has been ignored. This study, therefore, addressed aspects related to the distribution and abundance of representative species on the Agulhas Bank within a Geographic Information System (GIS). Four candidate species were chosen due to their importance either in numbers or unit mass to the South African demersal trawl fishery. The species also shared morphological and taxonomic similarities. The candidate species chosen were the two Cape hake species, shallow-water hake Meluccius capensis, and deep-water hake Merluccius paradoxus, and the two pleuronectiform species being Agulhas sole Austroglossus pectoralis and redspotted tonguesole Cynoglossus zanzibarensis. The use of a GIS was appropriate and allowed for hidden spatial patterns be exposed and illustrated visually, while also facilitating the quantification of the relationships between distribution/abundance and certain environmental predictors using statistical methods The Department of Marine and Coastal Management, Cape Town, supplied biological data in the form of length frequency and biomass information from spring (AprillMay) and autumn (September/October) cruises conducted between 1986 and 1993 on the R. V. Africana. The Council for National Geoscience, Cape Town, supplied sediment data for the entire southern African coastline. Initial exploratory data analysis highlighted potential relationships between environmental variables and abundance for each specie's life-history stanzas. Variations in spatial distribution were found to be significantly different between each life-history stanzas within species. Fish density as a function of the additive effects of the various environmental parameters, including temperature, depth and sediment type, was assessed using a Poisson Generalized Additive Model (GAM), while distribution was analysed with a logistic GAM. A predictive logistic model was then created, taking into consideration the importance of the predictor variables for each species, allowing for predictive estimates to be made for each species by inputting environmental information within the study area. The importance of certain environmental variables influencing distribution and abundance were noted. General patterns indicated that sediment was the most important to both the distribution and abundance of the two pleuronectiform species and juvenile life-history stanzas, while the adult gadoids' distribution and abundance appeared to be depth dependent.
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Naming students problems: an analysis of language-related discourses at a South African university
- Authors: Boughey, Chrissie
- Date: 2002
- Language: English
- Type: Article
- Identifier: vital:6086 , http://hdl.handle.net/10962/d1008484 , http://www.tandfonline.com/doi/pdf/10.1080/13562510220144798
- Description: This article examines a number of discourses that construct students 'problems' as they engage with tertiary study at a historically black South African university. These dominant discourses are then linked to Street's 'autonomous' model of literacy and Rampton's 'autonomous' model of applied linguistics in order to interrogate their ideological biases. Implications of the discourses for the provision of epistemological access to tertiary study are then explored. The article ends by indicating how a 'literacy across the curriculum' approach to working with students' difficulties could provide an alternative to current 'remedial' programmes.
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- Authors: Boughey, Chrissie
- Date: 2002
- Language: English
- Type: Article
- Identifier: vital:6086 , http://hdl.handle.net/10962/d1008484 , http://www.tandfonline.com/doi/pdf/10.1080/13562510220144798
- Description: This article examines a number of discourses that construct students 'problems' as they engage with tertiary study at a historically black South African university. These dominant discourses are then linked to Street's 'autonomous' model of literacy and Rampton's 'autonomous' model of applied linguistics in order to interrogate their ideological biases. Implications of the discourses for the provision of epistemological access to tertiary study are then explored. The article ends by indicating how a 'literacy across the curriculum' approach to working with students' difficulties could provide an alternative to current 'remedial' programmes.
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Narratiewe strategieë by die ondersoek van die verlede in twee romans, naamlik Lijken op liefde (1997) deur Astrid H. Roemer en Duiwelskloof (1998) deur André P. Brink
- Authors: Potgieter, Maretha
- Date: 2002
- Subjects: Roemer, Astrid. Lijken op liefde , Brink, André Philippus, 1935- Duiwelskloof
- Language: Afrikaans
- Type: Thesis , Masters , MA
- Identifier: vital:3578 , http://hdl.handle.net/10962/d1002151 , Roemer, Astrid. Lijken op liefde , Brink, André Philippus, 1935- Duiwelskloof
- Description: This study investigates some of the narrative strategies used by two novels, namely Lijken op Liefde (1997) by the Surinam born author Astrid H. Roemer and Duiwelskloof (1998) by the South African André P. Brink, in their exploration of and dialogue with traumatic pasts. Both texts are written within so-called postcolonial time frames, delve into the personal and collective past and attempt to provide a corrective on knowledges that used to be deemed not useful, unimportant or have been forgotten by official historiography. The theoretical base of the study is an eclectic mixture of both postcolonial and postmodern theories, throwing light on the strategies employed by these novels in order to understand, problematise and creatively exploit the past. , Hierdie studie kyk na sommige van die narratiewe strategieë binne twee romans, naamlik Lijken op Liefde (1997) deur die Surinaams-gebore outeur Astrid H. Roemer en Duiwelskloof (1998) deur die Suid-Afrikaner André P. Brink, in hulle ondersoek na en dialoog met die traumatiese verlede. Beide tekste is geskryf binne sogenaamde postkoloniale tydvakke, delf in die persoonlike en kollektiewe verlede, en verskaf ’n korrektief op die dinge wat as onbruikbaar of onbelangrik beskou is, of vergete geraak het binne die offisiële historiografie. Die teoretiese basis van die studie is ’n eklektiese mengsel van beide postkoloniale en postmoderne teorieë wat lig werp op die strategieë wat hierdie tekste gebruik om die verlede te verstaan, te problematiseer en kreatief te ontgin.
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- Authors: Potgieter, Maretha
- Date: 2002
- Subjects: Roemer, Astrid. Lijken op liefde , Brink, André Philippus, 1935- Duiwelskloof
- Language: Afrikaans
- Type: Thesis , Masters , MA
- Identifier: vital:3578 , http://hdl.handle.net/10962/d1002151 , Roemer, Astrid. Lijken op liefde , Brink, André Philippus, 1935- Duiwelskloof
- Description: This study investigates some of the narrative strategies used by two novels, namely Lijken op Liefde (1997) by the Surinam born author Astrid H. Roemer and Duiwelskloof (1998) by the South African André P. Brink, in their exploration of and dialogue with traumatic pasts. Both texts are written within so-called postcolonial time frames, delve into the personal and collective past and attempt to provide a corrective on knowledges that used to be deemed not useful, unimportant or have been forgotten by official historiography. The theoretical base of the study is an eclectic mixture of both postcolonial and postmodern theories, throwing light on the strategies employed by these novels in order to understand, problematise and creatively exploit the past. , Hierdie studie kyk na sommige van die narratiewe strategieë binne twee romans, naamlik Lijken op Liefde (1997) deur die Surinaams-gebore outeur Astrid H. Roemer en Duiwelskloof (1998) deur die Suid-Afrikaner André P. Brink, in hulle ondersoek na en dialoog met die traumatiese verlede. Beide tekste is geskryf binne sogenaamde postkoloniale tydvakke, delf in die persoonlike en kollektiewe verlede, en verskaf ’n korrektief op die dinge wat as onbruikbaar of onbelangrik beskou is, of vergete geraak het binne die offisiële historiografie. Die teoretiese basis van die studie is ’n eklektiese mengsel van beide postkoloniale en postmoderne teorieë wat lig werp op die strategieë wat hierdie tekste gebruik om die verlede te verstaan, te problematiseer en kreatief te ontgin.
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Nearest-neighbour analysis and the prevelance of woody plant competition in South African savannas
- Authors: Shackleton, Charlie M
- Date: 2002
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/181640 , vital:43754 , xlink:href="https://doi.org/10.1023/A:1014795505362"
- Description: Inter- and intra-specific competition has long been regarded as a significant determinant of the structure and function of woody plant communities in African savannas. The most widely used approach to detect the presence or absence of competition has been the use of nearest-neighbour methods. Although several studies have been published reporting the presence of competition in Acacia dominated communities, less than 20 plots have been sampled across all these studies. Results from broad-leaved communities are variable, and also based on a small sample number. Consequently, this study sought to assess the prevalence of competition from a large number of savanna sites (45), and to identify abiotic and biotic factors characterising sites with competition relative to those without. Using the nearest-neighbour method only four sites (9.3%) indicated the presence of inter-specific competition; two were Acacia dominated communities (18.2% of Acacia sites) and two were broad-leaved communities (7.7%). These four sites had a significantly higher mean annual rainfall and fewer woody species than sites without inter-specific competition. There were also significant relationships between the inter-specific competition index and the dominance index and the number of species at a site. In terms of intra-specific competition only ten of the 31 sites tested revealed a significant correlation between nearest-neighbour distance and summed canopy volume of the two neighbours. Seven were for Acacia species (55.6% of the Acacia species comparisons) and three were for broad-leaved species (21.4% of the broad-leaved species comparisons). Sites lacking evidence of intra-specific competition were at a significantly lower slope position and had a smaller proportion of small stems. The lower prevalence of competition in South African savannas detected in this study using the same method as previous studies is discussed, and the appropriateness of nearest-neighbour analysis is examined.
- Full Text:
- Authors: Shackleton, Charlie M
- Date: 2002
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/181640 , vital:43754 , xlink:href="https://doi.org/10.1023/A:1014795505362"
- Description: Inter- and intra-specific competition has long been regarded as a significant determinant of the structure and function of woody plant communities in African savannas. The most widely used approach to detect the presence or absence of competition has been the use of nearest-neighbour methods. Although several studies have been published reporting the presence of competition in Acacia dominated communities, less than 20 plots have been sampled across all these studies. Results from broad-leaved communities are variable, and also based on a small sample number. Consequently, this study sought to assess the prevalence of competition from a large number of savanna sites (45), and to identify abiotic and biotic factors characterising sites with competition relative to those without. Using the nearest-neighbour method only four sites (9.3%) indicated the presence of inter-specific competition; two were Acacia dominated communities (18.2% of Acacia sites) and two were broad-leaved communities (7.7%). These four sites had a significantly higher mean annual rainfall and fewer woody species than sites without inter-specific competition. There were also significant relationships between the inter-specific competition index and the dominance index and the number of species at a site. In terms of intra-specific competition only ten of the 31 sites tested revealed a significant correlation between nearest-neighbour distance and summed canopy volume of the two neighbours. Seven were for Acacia species (55.6% of the Acacia species comparisons) and three were for broad-leaved species (21.4% of the broad-leaved species comparisons). Sites lacking evidence of intra-specific competition were at a significantly lower slope position and had a smaller proportion of small stems. The lower prevalence of competition in South African savannas detected in this study using the same method as previous studies is discussed, and the appropriateness of nearest-neighbour analysis is examined.
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New views on the Jurassic Clarens Formation: volcano-sedimentary interaction
- Holzforster, Frank, Holzforster, Heike W, Marsh, Julian S
- Authors: Holzforster, Frank , Holzforster, Heike W , Marsh, Julian S
- Date: 2002
- Language: English
- Type: text , abstract
- Identifier: http://hdl.handle.net/10962/132716 , vital:36874
- Description: The Lower Jurassic Clarens Formation of the Great Karoo Basin is usually viewed in the literature as a aeolian and, in places, fluvio-aeolian deposit of tremendous thickness variation form 0-250 m thickness. Interaction with the overlying Karoo Flood Basalts, particularly in the Eastern Cape area and in Lesotho, has been noted but was never a major topic. Relatively widespread pyroclastic deposits sandwiched between the Clarens Formation and the Karoo Flood Basalts have been interpreted as flood-lahars.
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- Authors: Holzforster, Frank , Holzforster, Heike W , Marsh, Julian S
- Date: 2002
- Language: English
- Type: text , abstract
- Identifier: http://hdl.handle.net/10962/132716 , vital:36874
- Description: The Lower Jurassic Clarens Formation of the Great Karoo Basin is usually viewed in the literature as a aeolian and, in places, fluvio-aeolian deposit of tremendous thickness variation form 0-250 m thickness. Interaction with the overlying Karoo Flood Basalts, particularly in the Eastern Cape area and in Lesotho, has been noted but was never a major topic. Relatively widespread pyroclastic deposits sandwiched between the Clarens Formation and the Karoo Flood Basalts have been interpreted as flood-lahars.
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Non-governmental organizations, the state and the politics of rural development in Kenya with particular reference to Western Province
- Authors: Matanga, Frank Khachina
- Date: 2002
- Subjects: Non-governmental organizations -- Kenya , Rural development -- Kenya
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:2803 , http://hdl.handle.net/10962/d1003013 , Non-governmental organizations -- Kenya , Rural development -- Kenya
- Description: In recent decades, Non-Governmental Organizations (NGOs) have increasingly taken on development and political roles in Africa. This has partly been attributed to the New Policy Agenda (NPA) mounted by the international donors. The NPA is predicated on neo-liberal thinking advocating for an enlarged development role for the private sector and a minimalist state. This relatively new shift in development thought has been motivated by the declining capacity of the African state to deliver development and guarantee a liberal political system. This study, therefore, set out to empirically examine whether NGOs are capable of effectively playing their new-found development and political roles. The study was based on Kenya with the Western Province constituting the core research area. The fact that the Kenyan state has been gradually disengaging from the development process has created a vacuum of which the NGOs have attempted to fill. Equally important has been the observation that, for the greater part of the post-colonial period, the state has been largely authoritarian and therefore prompting a segment of civil society to take on political roles in an effort to force it to liberalize and democratize. Urban NGOs in particular, have been the most confrontational to the state with some remarkable success. Unlike their urban counterparts, rural-based NGOs have tended to be more developmental and play a politics of collaboration with the state. Many of the latter NGOs, although playing a significant role in rural development, have been co-opted into patron-client networks. Factors that influence NGOs= posture towards the state include the nature of their leadership, the extent of their nternational connections, and the level of resources at their disposal. The study=s principal conclusion, is that, in as much as NGOs and overall civil society have provided a basis for development and opposition to the state, there is an urgent and growing need for them to shift from a position of dependency, whether domestic or international, to relative autonomy. Only then, will their contributions be sustainable in society.
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- Authors: Matanga, Frank Khachina
- Date: 2002
- Subjects: Non-governmental organizations -- Kenya , Rural development -- Kenya
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:2803 , http://hdl.handle.net/10962/d1003013 , Non-governmental organizations -- Kenya , Rural development -- Kenya
- Description: In recent decades, Non-Governmental Organizations (NGOs) have increasingly taken on development and political roles in Africa. This has partly been attributed to the New Policy Agenda (NPA) mounted by the international donors. The NPA is predicated on neo-liberal thinking advocating for an enlarged development role for the private sector and a minimalist state. This relatively new shift in development thought has been motivated by the declining capacity of the African state to deliver development and guarantee a liberal political system. This study, therefore, set out to empirically examine whether NGOs are capable of effectively playing their new-found development and political roles. The study was based on Kenya with the Western Province constituting the core research area. The fact that the Kenyan state has been gradually disengaging from the development process has created a vacuum of which the NGOs have attempted to fill. Equally important has been the observation that, for the greater part of the post-colonial period, the state has been largely authoritarian and therefore prompting a segment of civil society to take on political roles in an effort to force it to liberalize and democratize. Urban NGOs in particular, have been the most confrontational to the state with some remarkable success. Unlike their urban counterparts, rural-based NGOs have tended to be more developmental and play a politics of collaboration with the state. Many of the latter NGOs, although playing a significant role in rural development, have been co-opted into patron-client networks. Factors that influence NGOs= posture towards the state include the nature of their leadership, the extent of their nternational connections, and the level of resources at their disposal. The study=s principal conclusion, is that, in as much as NGOs and overall civil society have provided a basis for development and opposition to the state, there is an urgent and growing need for them to shift from a position of dependency, whether domestic or international, to relative autonomy. Only then, will their contributions be sustainable in society.
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Nutrient digestibility in South African abalone (Haliotis Midae L.)
- Authors: Sales, James
- Date: 2002
- Subjects: Abalones -- Digestion Abalones -- Nutrition
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5305 , http://hdl.handle.net/10962/d1005150
- Description: The evaluation of potential alternative protein sources for the formulation of least-cost optimal diets to satisfy the nutrient requirements of South African abalone (Haliotis midae) has been hampered by the absence of a suitable, practical, replicable and reliable digestibility technique. A suitable lowcost faeces collection technique was developed in this study to obtain suitable quantities of excreta for analysis from this species. Acid-insoluble ash was identified as a reliable, replicable and safe internal marker in comparison to chromic oxide and crude fibre for use in nutrient digestibility studies with H. midae. This was validated by the consistency and repeatability of the results and by comparison to total collection of faeces. The traditional substitution method used in digestibility studies with fish to evaluate protein digestibility of feed ingredients was found to be unsuitable for H. midae. Apparent protein digestibility values exceeding 100 % derived through this method could be attributed to associative effects between feed ingredients, differential diet and faecal nutrient leaching, and mathematical artifacts in calculations when using substitution versus single protein diets. An ingredient particle size of less than 450 μm in comparison to particle size classes of above 450 μm was shown to enhance nutrient (dry matter, organic matter, protein, fat) digestibility and minimise dry matter leaching from diets. The dietary inclusion level of both pre-gelatinised maize starch and a-cellulose did not influence (P > 0.05) apparent nutrient (protein, fat, fiber, starch) digestibility. Using the above digestibility protocol amino acid availability of all plants ingredients currently used in the South African animal industry was evaluated for H. midae. Soybean meal (96.86 %) and lupins (96.51 %) presented the highest apparent mean amino acid availability of all plant protein ingredients evaluated with H. midae. Canola meal (94.21 %), faba beans (92.87 %) sunflower meal (92.77 %), peanut meal (87.39 %) and cottonseed meal (85.15 %) presented higher apparent mean amino acid availability values than fish meal (82.75 %). Apparent protein digestibility was highly correlated (r = 0.99) with mean apparent amino acid availability, while true amino acid availability was 1.88 % units higher than apparent amino acid availability for all ingredients tested. Predicted apparent protein digestibility in compound diets was within 1.1-6.5 % of determined values. Calcium phosphate mono dibasic presented the lowest (P < 0.05) dietary phosphorus leaching (51.51 % maximum) and highest apparent phosphorus digestibility (66.27 %) in comparison to other inorganic phosphorus sources. Based on the method of direct experimentation to determine the optimal dietary protein level using graded levels of dietary protein 28.1-35.9 % dietary protein from good quality sources is recommended for maximum growth of juvenile H. midae. This study provides a scientifically sound research tool including a faecal collection technique, suitable marker and assay technique that could be use in further studies to improve least-cost diet formulation for H. midae. Future nutritional studies in H. midae should primarily concentrate on reducing dietary nutrient leaching and improving the intake of nutrients in order to properly evaluate responses of this species to different dietary regimes.
- Full Text:
- Authors: Sales, James
- Date: 2002
- Subjects: Abalones -- Digestion Abalones -- Nutrition
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5305 , http://hdl.handle.net/10962/d1005150
- Description: The evaluation of potential alternative protein sources for the formulation of least-cost optimal diets to satisfy the nutrient requirements of South African abalone (Haliotis midae) has been hampered by the absence of a suitable, practical, replicable and reliable digestibility technique. A suitable lowcost faeces collection technique was developed in this study to obtain suitable quantities of excreta for analysis from this species. Acid-insoluble ash was identified as a reliable, replicable and safe internal marker in comparison to chromic oxide and crude fibre for use in nutrient digestibility studies with H. midae. This was validated by the consistency and repeatability of the results and by comparison to total collection of faeces. The traditional substitution method used in digestibility studies with fish to evaluate protein digestibility of feed ingredients was found to be unsuitable for H. midae. Apparent protein digestibility values exceeding 100 % derived through this method could be attributed to associative effects between feed ingredients, differential diet and faecal nutrient leaching, and mathematical artifacts in calculations when using substitution versus single protein diets. An ingredient particle size of less than 450 μm in comparison to particle size classes of above 450 μm was shown to enhance nutrient (dry matter, organic matter, protein, fat) digestibility and minimise dry matter leaching from diets. The dietary inclusion level of both pre-gelatinised maize starch and a-cellulose did not influence (P > 0.05) apparent nutrient (protein, fat, fiber, starch) digestibility. Using the above digestibility protocol amino acid availability of all plants ingredients currently used in the South African animal industry was evaluated for H. midae. Soybean meal (96.86 %) and lupins (96.51 %) presented the highest apparent mean amino acid availability of all plant protein ingredients evaluated with H. midae. Canola meal (94.21 %), faba beans (92.87 %) sunflower meal (92.77 %), peanut meal (87.39 %) and cottonseed meal (85.15 %) presented higher apparent mean amino acid availability values than fish meal (82.75 %). Apparent protein digestibility was highly correlated (r = 0.99) with mean apparent amino acid availability, while true amino acid availability was 1.88 % units higher than apparent amino acid availability for all ingredients tested. Predicted apparent protein digestibility in compound diets was within 1.1-6.5 % of determined values. Calcium phosphate mono dibasic presented the lowest (P < 0.05) dietary phosphorus leaching (51.51 % maximum) and highest apparent phosphorus digestibility (66.27 %) in comparison to other inorganic phosphorus sources. Based on the method of direct experimentation to determine the optimal dietary protein level using graded levels of dietary protein 28.1-35.9 % dietary protein from good quality sources is recommended for maximum growth of juvenile H. midae. This study provides a scientifically sound research tool including a faecal collection technique, suitable marker and assay technique that could be use in further studies to improve least-cost diet formulation for H. midae. Future nutritional studies in H. midae should primarily concentrate on reducing dietary nutrient leaching and improving the intake of nutrients in order to properly evaluate responses of this species to different dietary regimes.
- Full Text: