Southern African Journal of Gerontology, volume 5, number 1, April 1996
- Ferreira, Monica (editor), Moller, Valerie, HSRC/UCT Centre for Gerontology
- Authors: Ferreira, Monica (editor) , Moller, Valerie , HSRC/UCT Centre for Gerontology
- Date: 1996
- Subjects: Gerontology -- South Africa , Older people -- Care -- South Africa
- Language: English
- Type: Text
- Identifier: vital:8072 , http://hdl.handle.net/10962/d1012865
- Description: [From Editorial] This issue comprises a transdisciplinary mix of interesting and relevant papers ranging from a community-development intervention, to gerontolinguistics, to guidelines for new legislation, to community services in China. The issue begins with an article on infrastructure and equity for the elderly, in which authors Ross, Lerer and Phillips investigate the attitudes of older residents of Elim, a village situated in South Africa's Western Cape province, towards electrification of their village and homes. The creation of basic infrastructure in historically-disadvantaged areas throughout South Africa is a priority under the government's RDP. However, in this case study of Elim, the utility company which provides electricity to the village failed to consult the elderly residents on the developmental intervention and the benefits which electrification might have for them. The majority of the older residents who were interviewed were consequently negative about this new energy source. The advantages which electricity has over other fuels have distinct health and other developmental benefits, and in rural households older members are important decision makers on energy use. The study's findings indicate that developmental interventions in ruralbased communities should include a social-marketing component targeting older members of the community. The article by Makoni on discourse practices in first-time encounters between old and young Xhosa-speaking women represents an exciting development in gerontological research in the Southern African region. As far as we know, this is a first report on a linguistics study in an older population in the region. In his analysis of the conversations, Makoni notes the sociohistorical background against which the old women try to retain status and respect. He points out that while the elderly are a marginalized group, the youth in South African society have become empowered through their contributions to the political changes, which along with other social changes are seen by some to destabilize traditional seniority respect norms. , In his article Van Dokkum makes out a case for the development of legislation to protect older South Africans against abuse. He uses examples of new South African legislation to deter child abuse and vast legislation in the United States to protect older Americans, in outlining a proposal for local activists to campaign for adequate protection of elderly citizens. Zhu gives us an update on a massive community social-services programme for older people being implemented in the People's Republic of China. The programme partly aims to assist an increasing number of older people who find that they are no longer able to live with kin and must live independently. The programme already serves a staggering proportion of China's 104 million persons aged 60 years and above, although it is estimated that it currently only meets 30 percent of the demand. pensions and household structure in Namibia by Adamchak published in SAJG Volume 4, No 2 (October 1995), and Adamchak's response are welcome additions to this number. The journal encourages debate on papers that it publishes, and the letters also reflect the development and growth of gerontology and research on ageing in the Southern African region. Finally, gerontolinguist Makoni reviews Hamilton's (1994) book in which the author analyses her conversations with Elsie, an Alzheimer's disease patient in a "total institution" (Goffman, 1961). The book contributes to understanding of losses and changes in language use in sufferers of this disease as the dementia progresses. Makoni proposes topics for studies on this subject which might be carried out in Southern African countries, where the majority of dementing older Africans are cared for within the community and not in a long-term care institution.
- Full Text:
- Date Issued: 1996
- Authors: Ferreira, Monica (editor) , Moller, Valerie , HSRC/UCT Centre for Gerontology
- Date: 1996
- Subjects: Gerontology -- South Africa , Older people -- Care -- South Africa
- Language: English
- Type: Text
- Identifier: vital:8072 , http://hdl.handle.net/10962/d1012865
- Description: [From Editorial] This issue comprises a transdisciplinary mix of interesting and relevant papers ranging from a community-development intervention, to gerontolinguistics, to guidelines for new legislation, to community services in China. The issue begins with an article on infrastructure and equity for the elderly, in which authors Ross, Lerer and Phillips investigate the attitudes of older residents of Elim, a village situated in South Africa's Western Cape province, towards electrification of their village and homes. The creation of basic infrastructure in historically-disadvantaged areas throughout South Africa is a priority under the government's RDP. However, in this case study of Elim, the utility company which provides electricity to the village failed to consult the elderly residents on the developmental intervention and the benefits which electrification might have for them. The majority of the older residents who were interviewed were consequently negative about this new energy source. The advantages which electricity has over other fuels have distinct health and other developmental benefits, and in rural households older members are important decision makers on energy use. The study's findings indicate that developmental interventions in ruralbased communities should include a social-marketing component targeting older members of the community. The article by Makoni on discourse practices in first-time encounters between old and young Xhosa-speaking women represents an exciting development in gerontological research in the Southern African region. As far as we know, this is a first report on a linguistics study in an older population in the region. In his analysis of the conversations, Makoni notes the sociohistorical background against which the old women try to retain status and respect. He points out that while the elderly are a marginalized group, the youth in South African society have become empowered through their contributions to the political changes, which along with other social changes are seen by some to destabilize traditional seniority respect norms. , In his article Van Dokkum makes out a case for the development of legislation to protect older South Africans against abuse. He uses examples of new South African legislation to deter child abuse and vast legislation in the United States to protect older Americans, in outlining a proposal for local activists to campaign for adequate protection of elderly citizens. Zhu gives us an update on a massive community social-services programme for older people being implemented in the People's Republic of China. The programme partly aims to assist an increasing number of older people who find that they are no longer able to live with kin and must live independently. The programme already serves a staggering proportion of China's 104 million persons aged 60 years and above, although it is estimated that it currently only meets 30 percent of the demand. pensions and household structure in Namibia by Adamchak published in SAJG Volume 4, No 2 (October 1995), and Adamchak's response are welcome additions to this number. The journal encourages debate on papers that it publishes, and the letters also reflect the development and growth of gerontology and research on ageing in the Southern African region. Finally, gerontolinguist Makoni reviews Hamilton's (1994) book in which the author analyses her conversations with Elsie, an Alzheimer's disease patient in a "total institution" (Goffman, 1961). The book contributes to understanding of losses and changes in language use in sufferers of this disease as the dementia progresses. Makoni proposes topics for studies on this subject which might be carried out in Southern African countries, where the majority of dementing older Africans are cared for within the community and not in a long-term care institution.
- Full Text:
- Date Issued: 1996
Southern African Journal of Gerontology, volume 5, number 2, October 1996
- Ferreira, Monica (editor), Moller, Valerie, HSRC/UCT Centre for Gerontology
- Authors: Ferreira, Monica (editor) , Moller, Valerie , HSRC/UCT Centre for Gerontology
- Date: 1996
- Subjects: Gerontology -- South Africa , Older people -- Care -- South Africa
- Language: English
- Type: Text
- Identifier: vital:8073 , http://hdl.handle.net/10962/d1012867
- Description: The October 1996 number of SAJG is a special issue on "Gender, ageing and empowerment in Africa." The guest editor of the special issue is Maria Cattell of Millersville University, Pennsylvania, USA, who has conducted substantial research on older Kenyans and more recently on Zulu grandmothers. Dr Cattell is the President of the global Association of Anthropology and Gerontology (AAGE). The issue will comprise research papers from authors in several African countries, and will provide valuable data and experience of ageing in Africa for transnational comparison.
- Full Text:
- Date Issued: 1996
- Authors: Ferreira, Monica (editor) , Moller, Valerie , HSRC/UCT Centre for Gerontology
- Date: 1996
- Subjects: Gerontology -- South Africa , Older people -- Care -- South Africa
- Language: English
- Type: Text
- Identifier: vital:8073 , http://hdl.handle.net/10962/d1012867
- Description: The October 1996 number of SAJG is a special issue on "Gender, ageing and empowerment in Africa." The guest editor of the special issue is Maria Cattell of Millersville University, Pennsylvania, USA, who has conducted substantial research on older Kenyans and more recently on Zulu grandmothers. Dr Cattell is the President of the global Association of Anthropology and Gerontology (AAGE). The issue will comprise research papers from authors in several African countries, and will provide valuable data and experience of ageing in Africa for transnational comparison.
- Full Text:
- Date Issued: 1996
Observations of glitches in PSR 0833-45 and 1641-45
- Authors: Flanagan, Claire Susan
- Date: 1996
- Subjects: Pulsars Neutron stars
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5480 , http://hdl.handle.net/10962/d1005266
- Description: An eleven-year series of radio timing observations of 0833- 45 (Vela) and PSR 1641- 45 is presented. During this time, five large spin-ups ("glitches") were observed in 0833- 45 and one in 1641-45. The stellar response to these events is investigated, and the three relat ively long complete inter-glitch intervals in 0833-45 are modeled. The results are of relevance to studies of the interiors of neutron stars. The initial aim of the project - to obtain good observational coverage of large glitches in the Vela pulsar - was successfully achieved, and high quality observations of the periods between glitches were obtained as a by-product. The results of the analysis presented here provide support for the existence of both linear and non-linear coupling in the Vela pulsar, and put a limit on the former in PSR 1641- 45. The recently observed existence of a rapidly recovering component of part of a glitch in Vela was verified in the subsequent glitch, although there is now evidence to contradict the suggestion that this component involves a particular region of the star that is implicated in every glitch. Observations of a recent glitch in the same pulsar have resolved a small component of the spin-up; such a component has not been reported for any other large glitch.
- Full Text:
- Date Issued: 1996
- Authors: Flanagan, Claire Susan
- Date: 1996
- Subjects: Pulsars Neutron stars
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5480 , http://hdl.handle.net/10962/d1005266
- Description: An eleven-year series of radio timing observations of 0833- 45 (Vela) and PSR 1641- 45 is presented. During this time, five large spin-ups ("glitches") were observed in 0833- 45 and one in 1641-45. The stellar response to these events is investigated, and the three relat ively long complete inter-glitch intervals in 0833-45 are modeled. The results are of relevance to studies of the interiors of neutron stars. The initial aim of the project - to obtain good observational coverage of large glitches in the Vela pulsar - was successfully achieved, and high quality observations of the periods between glitches were obtained as a by-product. The results of the analysis presented here provide support for the existence of both linear and non-linear coupling in the Vela pulsar, and put a limit on the former in PSR 1641- 45. The recently observed existence of a rapidly recovering component of part of a glitch in Vela was verified in the subsequent glitch, although there is now evidence to contradict the suggestion that this component involves a particular region of the star that is implicated in every glitch. Observations of a recent glitch in the same pulsar have resolved a small component of the spin-up; such a component has not been reported for any other large glitch.
- Full Text:
- Date Issued: 1996
A networking approach to sharing music studio resources
- Authors: Foss, Richard John
- Date: 1996
- Subjects: MIDI (Standard) Computer sound processing Sound -- Recording and reproducing -- Digital techniques
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4659 , http://hdl.handle.net/10962/d1006660
- Description: This thesis investigates the extent to which networking technology can be used to provide remote workstation access to a pool of shared music studio resources. A pilot system is described in which MIDI messages, studio control data, and audio signals flow between the workstations and a studio server. A booking and timing facility avoids contention and allows for accurate reports of studio usage. The operation of the system has been evaluated in terms of its ability to satislY three fundamental goals, namely the remote, shared and centralized access to studio resources. Three essential network configurations have been identified, incorporating a mix of star and bus topologies, and their relative potential for satisfYing the fundamental goals has been highlighted.
- Full Text:
- Date Issued: 1996
- Authors: Foss, Richard John
- Date: 1996
- Subjects: MIDI (Standard) Computer sound processing Sound -- Recording and reproducing -- Digital techniques
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4659 , http://hdl.handle.net/10962/d1006660
- Description: This thesis investigates the extent to which networking technology can be used to provide remote workstation access to a pool of shared music studio resources. A pilot system is described in which MIDI messages, studio control data, and audio signals flow between the workstations and a studio server. A booking and timing facility avoids contention and allows for accurate reports of studio usage. The operation of the system has been evaluated in terms of its ability to satislY three fundamental goals, namely the remote, shared and centralized access to studio resources. Three essential network configurations have been identified, incorporating a mix of star and bus topologies, and their relative potential for satisfYing the fundamental goals has been highlighted.
- Full Text:
- Date Issued: 1996
Rural and urban population trends in the Eastern Cape Province, 1936-1991
- Authors: Fox, R C , Tipler, D J
- Date: 1996
- Subjects: Demography -- South Africa -- Eastern Cape Eastern Cape (South Africa) -- Population Rural-urban migration -- South Africa -- Eastern Cape Relocation (Housing) -- South Africa -- Eastern Cape Relocation (Housing) -- South Africa Rural population -- South Africa -- Eastern Cape Rural population -- South Africa Cities and towns -- South Africa -- Growth
- Language: English
- Type: Book , Text
- Identifier: http://hdl.handle.net/10962/2123 , vital:20257 , ISBN 0868103179
- Description: This study is an attempt to analyze the impact of apartheid policy on population trends, particularly geographical distributions within the Eastern Cape Province for the period 1936 to 1991. Rogerson and McCarthy (1992), in the most recent overview of geographical work, argued that there is scope for studies such as this which integrate spatio-demographic trends with historical and cultural geography. Accordingly, this study delimits population trends and examines the impact of state policy. A Geographical Information System (GIS) was used as the main research tool for the storage and manipulation of spatio-demographic data. In terms of the impact of state policy, Christopher's (1994) Atlas of Apartheid provided a comprehensive outline of the historical context which forms the background to the period of study. His book shows how the geographical distribution of race groups within South Africa was largely brought about through the implementation of apartheid legislation. Horrell's (1978) Laws Affecting Race Relations in South Africa, 1948-1976 outlined the apartheid legislation at work during the period up to 1976. The geographical distribution of race groups within the Eastern Cape Province was influenced by a variety of legislative measures and policies from the creation of the reserve areas, through the restrictions on Group Areas, as well as various policies including influx control, border industry/industrial decentralization, forced removals and coloured labour preference. The most significant acts and policies which impacted on the Province are outlined below. , Digitised by Rhodes University Library on behalf of the Institute of Social and Economic Research (ISER)
- Full Text:
- Date Issued: 1996
- Authors: Fox, R C , Tipler, D J
- Date: 1996
- Subjects: Demography -- South Africa -- Eastern Cape Eastern Cape (South Africa) -- Population Rural-urban migration -- South Africa -- Eastern Cape Relocation (Housing) -- South Africa -- Eastern Cape Relocation (Housing) -- South Africa Rural population -- South Africa -- Eastern Cape Rural population -- South Africa Cities and towns -- South Africa -- Growth
- Language: English
- Type: Book , Text
- Identifier: http://hdl.handle.net/10962/2123 , vital:20257 , ISBN 0868103179
- Description: This study is an attempt to analyze the impact of apartheid policy on population trends, particularly geographical distributions within the Eastern Cape Province for the period 1936 to 1991. Rogerson and McCarthy (1992), in the most recent overview of geographical work, argued that there is scope for studies such as this which integrate spatio-demographic trends with historical and cultural geography. Accordingly, this study delimits population trends and examines the impact of state policy. A Geographical Information System (GIS) was used as the main research tool for the storage and manipulation of spatio-demographic data. In terms of the impact of state policy, Christopher's (1994) Atlas of Apartheid provided a comprehensive outline of the historical context which forms the background to the period of study. His book shows how the geographical distribution of race groups within South Africa was largely brought about through the implementation of apartheid legislation. Horrell's (1978) Laws Affecting Race Relations in South Africa, 1948-1976 outlined the apartheid legislation at work during the period up to 1976. The geographical distribution of race groups within the Eastern Cape Province was influenced by a variety of legislative measures and policies from the creation of the reserve areas, through the restrictions on Group Areas, as well as various policies including influx control, border industry/industrial decentralization, forced removals and coloured labour preference. The most significant acts and policies which impacted on the Province are outlined below. , Digitised by Rhodes University Library on behalf of the Institute of Social and Economic Research (ISER)
- Full Text:
- Date Issued: 1996
Bleak future for multi-party elections in Kenya
- Authors: Fox, Roddy C
- Date: 1996
- Language: English
- Type: Article
- Identifier: vital:6683 , http://hdl.handle.net/10962/d1006681
- Description: With attention turning towards Kenya's second multi-party elections, due to be held before the end of 1997, it is imperative to look back to the flaws in the system which helped deliver President Daniel arap Moi and the Kenya African National Union (KANU) their victories in 1992. At present there is no sign of these defects being eradicated and the creation of new districts since then has demonstrated the Government's intention of enhancing an already biased structure. The underlying distribution of tribes and ethnic groups has had a fundamental impact on the electoral geography of Kenya, since they have controlled the delimitation of both the parliamentary constituencies and the administrative machinery of the whole country.
- Full Text:
- Date Issued: 1996
- Authors: Fox, Roddy C
- Date: 1996
- Language: English
- Type: Article
- Identifier: vital:6683 , http://hdl.handle.net/10962/d1006681
- Description: With attention turning towards Kenya's second multi-party elections, due to be held before the end of 1997, it is imperative to look back to the flaws in the system which helped deliver President Daniel arap Moi and the Kenya African National Union (KANU) their victories in 1992. At present there is no sign of these defects being eradicated and the creation of new districts since then has demonstrated the Government's intention of enhancing an already biased structure. The underlying distribution of tribes and ethnic groups has had a fundamental impact on the electoral geography of Kenya, since they have controlled the delimitation of both the parliamentary constituencies and the administrative machinery of the whole country.
- Full Text:
- Date Issued: 1996
The role of microzooplankton in carbon cycling in the Southern Ocean
- Authors: Froneman, Pierre William
- Date: 1996
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:21066 , http://hdl.handle.net/10962/6234
- Description: A 3-year study was carried out on the role of microzooplankton in carbon cycling in the south Atlantic and the Atlantic sector of the Southern Ocean. Microzooplankton grazing impact on phytoplankton was estimated during austral summer and winter employing the dilution technique. Carnivory by larger zooplankton on microzooplankton during summer was estimated using in vitro incubations. Microzooplankton assemblages were always dominated by protozoans comprising ciliates and dinoflagellates. In the ( 20 um chlorophyll fraction, microzooplankton grazing was sufficient to control the growth of the nano- and picophytoplankton suggesting that, where larger microphytoplankton cells dominate, micro zooplankton maintain the background concentrations of the nano- and picophytoplankton. During winter, when small nano- and picophytoplankton cells dominate total chlorophyll concentrations, the microzooplankton grazing impact on phytoplankton is dramatically increased. Microzooplankton removed on average 37% of the initial phytoplankton stock or 70% of the daily phytoplankton production. These results suggest that in winter, micro zooplankton are the main sink for phytoplankton production. Carnivory experiments conducted with selected meso- (copepods) and macro zooplankton (euphausiids and tunicates) showed that all species examined consumed micro zooplankton in the presence of substantial chlorophyll concentrations. Microzooplankton can, therefore, be regarded as trophic intermediates between bacterioplankton, small phytoplankton cells and larger zooplankton species in the Southern Ocean. The results of this investigation suggest a spatiotemporal shift in efficiency of the biological pump mediated by changes in the size composition of the phytoplankton assemblages. South of the Antarctic Polar Front (APF) large IV microphytoplankton cells dominate the summer chlorophyll biomass, suggesting that larger zooplankton grazers represent the main sink for phytoplankton production. Under these conditions, carbon flux to the interior of the ocean will be high due to diel vertical migrations by grazers and the production of large, fast sinking faecal pellets. The sedimentation of large phytoplankton cells also contributes to flux. In the permanently open waters south of the APF and throughout the Southern Ocean during winter, small phytoplankton cells dominate total chlorophyll, resulting in the microbial loop being the main sink for phytoplankton production. The close coupling between the micro zooplankton and the microbial loop dramatically reduces the transfer of organic carbon from the surface layers to depth. Carnivory by metazoans on microzooplankton may reduce the high grazing impact of micro zooplankton and, may also represent an important source of carbon flux originating from the microbial loop.
- Full Text:
- Date Issued: 1996
- Authors: Froneman, Pierre William
- Date: 1996
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:21066 , http://hdl.handle.net/10962/6234
- Description: A 3-year study was carried out on the role of microzooplankton in carbon cycling in the south Atlantic and the Atlantic sector of the Southern Ocean. Microzooplankton grazing impact on phytoplankton was estimated during austral summer and winter employing the dilution technique. Carnivory by larger zooplankton on microzooplankton during summer was estimated using in vitro incubations. Microzooplankton assemblages were always dominated by protozoans comprising ciliates and dinoflagellates. In the ( 20 um chlorophyll fraction, microzooplankton grazing was sufficient to control the growth of the nano- and picophytoplankton suggesting that, where larger microphytoplankton cells dominate, micro zooplankton maintain the background concentrations of the nano- and picophytoplankton. During winter, when small nano- and picophytoplankton cells dominate total chlorophyll concentrations, the microzooplankton grazing impact on phytoplankton is dramatically increased. Microzooplankton removed on average 37% of the initial phytoplankton stock or 70% of the daily phytoplankton production. These results suggest that in winter, micro zooplankton are the main sink for phytoplankton production. Carnivory experiments conducted with selected meso- (copepods) and macro zooplankton (euphausiids and tunicates) showed that all species examined consumed micro zooplankton in the presence of substantial chlorophyll concentrations. Microzooplankton can, therefore, be regarded as trophic intermediates between bacterioplankton, small phytoplankton cells and larger zooplankton species in the Southern Ocean. The results of this investigation suggest a spatiotemporal shift in efficiency of the biological pump mediated by changes in the size composition of the phytoplankton assemblages. South of the Antarctic Polar Front (APF) large IV microphytoplankton cells dominate the summer chlorophyll biomass, suggesting that larger zooplankton grazers represent the main sink for phytoplankton production. Under these conditions, carbon flux to the interior of the ocean will be high due to diel vertical migrations by grazers and the production of large, fast sinking faecal pellets. The sedimentation of large phytoplankton cells also contributes to flux. In the permanently open waters south of the APF and throughout the Southern Ocean during winter, small phytoplankton cells dominate total chlorophyll, resulting in the microbial loop being the main sink for phytoplankton production. The close coupling between the micro zooplankton and the microbial loop dramatically reduces the transfer of organic carbon from the surface layers to depth. Carnivory by metazoans on microzooplankton may reduce the high grazing impact of micro zooplankton and, may also represent an important source of carbon flux originating from the microbial loop.
- Full Text:
- Date Issued: 1996
Early Cretaceous alluvial palaeosols (Kirkwood formation, Algoa Basin, South Africa) and their palaeoenvironmental and palaeoclimatological significance
- Authors: Frost, Susan
- Date: 1996
- Subjects: Paleopedology -- South Africa -- Eastern Cape , Paleoclimatology -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4939 , http://hdl.handle.net/10962/d1005551 , Paleopedology -- South Africa -- Eastern Cape , Paleoclimatology -- South Africa -- Eastern Cape
- Description: The Kirkwood Formation in the Bushman's River area of the Algoa Basin is characterised by a number of fining-upward cycles. These have been interpreted as indicating deposition in a dynamic aggrading meandering river system with the channel deposits (conglomerates grading upwards into sandstones) fining upward into the overbank deposits (mudrocks). Channel, channel-margin and overbank deposits were recognised. The three mudrock sequences logged comprise compound pedofacies sequences of multistorey, simple and cumulative palaeosols. Distinctive palaeopedological features, such as root traces and pedotubules, soil horizons and structures, mottles, and iron-rich and calcareous glaebules and calcareous hardpan lenses and layers were used to identify a number of palaeosols within the mudrock sequences. Each mudrock sequence comprises multistorey entisol, inceptisol, alfisol, ultisol, aridisol and vertisol profiles at different stags of pedogenic maturity. The entisols and inceptisols are relatively immature profiles formed close to the meandering river channel and are classified as channel-margin palaeosols. The ultisols, alfisols, aridisols and vertisols are more mature and formed at some distance from the channel. They are classified as proximal floodbasin or distal floodbasin palaeosols depending on their maturity, distance from the channel and grain-size. Slickensides, desiccation cracks, and iron-rich concretions occur, indicating multiple cycles of wetting and drying. A low water-table beneath the floodplain is indicated by both the prominent maroon-brown colouration of the mudstones, caused by oxidation during deposition, and the general lack of evaporites in the sequence. Calcretes comprising calcic and petrocalcic horizons are very common in the lower mudrock sequence, rare in the middle mudrock sequence and relatively common in the upper mudrock sequence. The calcretes generally consist a nodular zone which may, in some cases, be capped by a thin hardpan layer. The calcic palaeosols commonly show stages of carbonate accumulation which indicate at least 10 000 years of formation. The lack of calcrete formation in some of the profiles may indicate frequent flooding and high sediment accretion rates or a decrease in the influx of Ca²⁺-rich aeolian dust into the depositional basin. Clay alluviation is common in many of the profiles and soil structures are commonly well developed. The palaeosols are interpreted as having formed on an aggrading floodplain in a warm to hot (25-30°C), semi-arid climate with a low but seasonal rainfall (100-500mm per annum).
- Full Text:
- Date Issued: 1996
- Authors: Frost, Susan
- Date: 1996
- Subjects: Paleopedology -- South Africa -- Eastern Cape , Paleoclimatology -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4939 , http://hdl.handle.net/10962/d1005551 , Paleopedology -- South Africa -- Eastern Cape , Paleoclimatology -- South Africa -- Eastern Cape
- Description: The Kirkwood Formation in the Bushman's River area of the Algoa Basin is characterised by a number of fining-upward cycles. These have been interpreted as indicating deposition in a dynamic aggrading meandering river system with the channel deposits (conglomerates grading upwards into sandstones) fining upward into the overbank deposits (mudrocks). Channel, channel-margin and overbank deposits were recognised. The three mudrock sequences logged comprise compound pedofacies sequences of multistorey, simple and cumulative palaeosols. Distinctive palaeopedological features, such as root traces and pedotubules, soil horizons and structures, mottles, and iron-rich and calcareous glaebules and calcareous hardpan lenses and layers were used to identify a number of palaeosols within the mudrock sequences. Each mudrock sequence comprises multistorey entisol, inceptisol, alfisol, ultisol, aridisol and vertisol profiles at different stags of pedogenic maturity. The entisols and inceptisols are relatively immature profiles formed close to the meandering river channel and are classified as channel-margin palaeosols. The ultisols, alfisols, aridisols and vertisols are more mature and formed at some distance from the channel. They are classified as proximal floodbasin or distal floodbasin palaeosols depending on their maturity, distance from the channel and grain-size. Slickensides, desiccation cracks, and iron-rich concretions occur, indicating multiple cycles of wetting and drying. A low water-table beneath the floodplain is indicated by both the prominent maroon-brown colouration of the mudstones, caused by oxidation during deposition, and the general lack of evaporites in the sequence. Calcretes comprising calcic and petrocalcic horizons are very common in the lower mudrock sequence, rare in the middle mudrock sequence and relatively common in the upper mudrock sequence. The calcretes generally consist a nodular zone which may, in some cases, be capped by a thin hardpan layer. The calcic palaeosols commonly show stages of carbonate accumulation which indicate at least 10 000 years of formation. The lack of calcrete formation in some of the profiles may indicate frequent flooding and high sediment accretion rates or a decrease in the influx of Ca²⁺-rich aeolian dust into the depositional basin. Clay alluviation is common in many of the profiles and soil structures are commonly well developed. The palaeosols are interpreted as having formed on an aggrading floodplain in a warm to hot (25-30°C), semi-arid climate with a low but seasonal rainfall (100-500mm per annum).
- Full Text:
- Date Issued: 1996
Virtual sculpting : an investigation of directly manipulated free-form deformation in a virtual environment
- Authors: Gain, James Edward
- Date: 1996
- Subjects: Computer simulation , Computer graphics , Virtual reality
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4660 , http://hdl.handle.net/10962/d1006661 , Computer simulation , Computer graphics , Virtual reality
- Description: This thesis presents a Virtual Sculpting system, which addresses the problem of Free-Form Solid Modelling. The disparate elements of a Polygon-Mesh representation, a Directly Manipulated Free-Form Deformation sculpting tool, and a Virtual Environment are drawn into a cohesive whole under the mantle of a clay-sculpting metaphor. This enables a user to mould and manipulate a synthetic solid interactively as if it were composed of malleable clay. The focus of this study is on the interactivity, intuitivity and versatility of such a system. To this end, a range of improvements is investigated which significantly enhances the efficiency and correctness of Directly Manipulated Free-Form Deformation, both separately and as a seamless component of the Virtual Sculpting system.
- Full Text:
- Date Issued: 1996
- Authors: Gain, James Edward
- Date: 1996
- Subjects: Computer simulation , Computer graphics , Virtual reality
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4660 , http://hdl.handle.net/10962/d1006661 , Computer simulation , Computer graphics , Virtual reality
- Description: This thesis presents a Virtual Sculpting system, which addresses the problem of Free-Form Solid Modelling. The disparate elements of a Polygon-Mesh representation, a Directly Manipulated Free-Form Deformation sculpting tool, and a Virtual Environment are drawn into a cohesive whole under the mantle of a clay-sculpting metaphor. This enables a user to mould and manipulate a synthetic solid interactively as if it were composed of malleable clay. The focus of this study is on the interactivity, intuitivity and versatility of such a system. To this end, a range of improvements is investigated which significantly enhances the efficiency and correctness of Directly Manipulated Free-Form Deformation, both separately and as a seamless component of the Virtual Sculpting system.
- Full Text:
- Date Issued: 1996
An analysis of the experience of the acute phase of traumatic spinal cord injury in a South African spinal unit
- Authors: Gaitelband, Philip Joseph
- Date: 1996
- Subjects: Spinal cord -- Wounds and injuries -- Psychological aspects , Spinal cord -- Wounds and injuries -- Patients -- Rehabilitation
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2978 , http://hdl.handle.net/10962/d1002487 , Spinal cord -- Wounds and injuries -- Psychological aspects , Spinal cord -- Wounds and injuries -- Patients -- Rehabilitation
- Description: This study aims to explore, and to a certain extent to clarify, what it means psychologically to experience Traumatic spinal cord injury (TSCI) in a South African spinal unit. The target time chosen for analysis is the acute medical period. The study presents a review of the literature on psychological adjustment to TSCI and then proceeds to introduce and extensively articulate the hermeneutic approach and methodology. Subsequently, an interpretive research strategy is presented for the purpose of studying the acute phase of TSCI. The data for the study was obtained by means of three dialogical interviews which were tape recorded, transcribed and analyzed with~n a cyclical framework consisting of three interdependent levels. The interpretive procedure is modeled upon the 'reading guide' developed by Brown, Tappan, Gilligan, Miller and Argyris (1989). The analysis follows a course from the individual psychological descriptions of the experience to the generation of a general, nomothetic narrative account of the acute phase. The findings are then discussed in relation to the existing literature and evaluated on the basis of the goals of the study. The study highlights the value of some of the 'stage' ways of thinking about SCI adjustment, while simultaneously stressing the need for placing adjustment within a more personalized, and individually meaningful context. Significant differences between the psycho-physical experiences of patients in the categories of complete and -incomplete SCI were found, which suggests that a sharper distinction be made in the literature between these two groups, in order to account for the marked variations in their experiences.-- The study also contains a number of shortcomings, such as a lack of understanding about certain historical and contextual factors which may have mediated the experiences of the trauma for the individuals concerned. These shortcomings and some suggestions fro their resolution are then discussed. The study concludes with an evaluation of the research strategy and methodology and also offers some suggestions for future research.
- Full Text:
- Date Issued: 1996
- Authors: Gaitelband, Philip Joseph
- Date: 1996
- Subjects: Spinal cord -- Wounds and injuries -- Psychological aspects , Spinal cord -- Wounds and injuries -- Patients -- Rehabilitation
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2978 , http://hdl.handle.net/10962/d1002487 , Spinal cord -- Wounds and injuries -- Psychological aspects , Spinal cord -- Wounds and injuries -- Patients -- Rehabilitation
- Description: This study aims to explore, and to a certain extent to clarify, what it means psychologically to experience Traumatic spinal cord injury (TSCI) in a South African spinal unit. The target time chosen for analysis is the acute medical period. The study presents a review of the literature on psychological adjustment to TSCI and then proceeds to introduce and extensively articulate the hermeneutic approach and methodology. Subsequently, an interpretive research strategy is presented for the purpose of studying the acute phase of TSCI. The data for the study was obtained by means of three dialogical interviews which were tape recorded, transcribed and analyzed with~n a cyclical framework consisting of three interdependent levels. The interpretive procedure is modeled upon the 'reading guide' developed by Brown, Tappan, Gilligan, Miller and Argyris (1989). The analysis follows a course from the individual psychological descriptions of the experience to the generation of a general, nomothetic narrative account of the acute phase. The findings are then discussed in relation to the existing literature and evaluated on the basis of the goals of the study. The study highlights the value of some of the 'stage' ways of thinking about SCI adjustment, while simultaneously stressing the need for placing adjustment within a more personalized, and individually meaningful context. Significant differences between the psycho-physical experiences of patients in the categories of complete and -incomplete SCI were found, which suggests that a sharper distinction be made in the literature between these two groups, in order to account for the marked variations in their experiences.-- The study also contains a number of shortcomings, such as a lack of understanding about certain historical and contextual factors which may have mediated the experiences of the trauma for the individuals concerned. These shortcomings and some suggestions fro their resolution are then discussed. The study concludes with an evaluation of the research strategy and methodology and also offers some suggestions for future research.
- Full Text:
- Date Issued: 1996
Redistribution and taxation in South Africa : inaugural lecture delivered at Rhodes University
- Authors: Gavin, Wesley J
- Date: 1996
- Subjects: Taxation -- South Africa , Wealth -- Moral and ethical aspects , South Africa -- Economic policy
- Language: English
- Type: Text
- Identifier: vital:627 , http://hdl.handle.net/10962/d1020696 , ISBN 0868103292
- Description: Inaugural lecture delivered at Rhodes University , Rhodes University Libraries (Digitisation)
- Full Text:
- Date Issued: 1996
- Authors: Gavin, Wesley J
- Date: 1996
- Subjects: Taxation -- South Africa , Wealth -- Moral and ethical aspects , South Africa -- Economic policy
- Language: English
- Type: Text
- Identifier: vital:627 , http://hdl.handle.net/10962/d1020696 , ISBN 0868103292
- Description: Inaugural lecture delivered at Rhodes University , Rhodes University Libraries (Digitisation)
- Full Text:
- Date Issued: 1996
A cross-cultural study of eating disordered behaviour in female university residence students
- Authors: Geach, Michele Fiona
- Date: 1996
- Subjects: Eating disorders -- South Africa -- Cross-cultural studies Women college students -- South Africa
- Language: English
- Type: Thesis , Masters , MSocSc
- Identifier: vital:3197 , http://hdl.handle.net/10962/d1009452
- Description: The compilation of information on the incidence of eating disorders in South African university residence women has been identified as an urgent matter by the National Eating Disorders Coordinating Committee (NEDCC). This study was undertaken to determine the degree of eating disordered behaviour across cultures in female university residence students from the University of Natal, Durban and Pietermaritzburg campuses, and the University of Durban Westville. The Eating Disorder Inventory (EDI) was completed by 39 black, 41 white, 6 Indian and 4 Coloured students. It was hypothesised that white women would show higher rates of disordered eating; that black women in more advanced years of study ie. those who are more acculturated, would show more disordered eating behaviour than first year black students; that black females would demonstrate higher Body Mass Index (BMI) scores than white students; and that a positive relationship would be found between Socio-economic status (SES) and disordered eating. The results of this study indicated that there was no significant difference in disordered eating among black and white female students. Degree of disordered eating did not increase with year of study. Although black students demonstrated significantly higher BMI scores than white students, there was no difference in body dissatisfaction scores. Furthermore there was no relationship found between SES and degree of disordered eating behaviour. An attempt is made to explain these results by exploring the role of acculturation to Western appearance standards.
- Full Text:
- Date Issued: 1996
- Authors: Geach, Michele Fiona
- Date: 1996
- Subjects: Eating disorders -- South Africa -- Cross-cultural studies Women college students -- South Africa
- Language: English
- Type: Thesis , Masters , MSocSc
- Identifier: vital:3197 , http://hdl.handle.net/10962/d1009452
- Description: The compilation of information on the incidence of eating disorders in South African university residence women has been identified as an urgent matter by the National Eating Disorders Coordinating Committee (NEDCC). This study was undertaken to determine the degree of eating disordered behaviour across cultures in female university residence students from the University of Natal, Durban and Pietermaritzburg campuses, and the University of Durban Westville. The Eating Disorder Inventory (EDI) was completed by 39 black, 41 white, 6 Indian and 4 Coloured students. It was hypothesised that white women would show higher rates of disordered eating; that black women in more advanced years of study ie. those who are more acculturated, would show more disordered eating behaviour than first year black students; that black females would demonstrate higher Body Mass Index (BMI) scores than white students; and that a positive relationship would be found between Socio-economic status (SES) and disordered eating. The results of this study indicated that there was no significant difference in disordered eating among black and white female students. Degree of disordered eating did not increase with year of study. Although black students demonstrated significantly higher BMI scores than white students, there was no difference in body dissatisfaction scores. Furthermore there was no relationship found between SES and degree of disordered eating behaviour. An attempt is made to explain these results by exploring the role of acculturation to Western appearance standards.
- Full Text:
- Date Issued: 1996
A review of the Southern African gobiid fish genus Caffrogobius Smitt, 1900
- Goren, Menachem, J.L.B. Smith Institute of Ichthyology
- Authors: Goren, Menachem , J.L.B. Smith Institute of Ichthyology
- Date: 1996-09
- Subjects: Fishes -- South Africa , Gobiidae
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10962/70972 , vital:29766 , 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. 57 , The genus Caffrogobius Smitt, 1900 is composed of seven species. The members of the genus are moderate size gobies, reaching a length of 10-14 cm (SL). The species of the genus are characterized by a combination of the following characters: Cheek papillae pattern transverse; dorsal segmented rays: 9-14; anal segmented rays: 8-12; caudal segmented rays: 16-18; pectoral rays: 16-23. Scales along the body: 30-64; transverse rows of scales: 9-23; vertebrae: 27 (11+16 or 10+17); formula of fin pterygiophores: 3-22110. Six species of Caffrogobius are found around the southern part of the African continent (Mozambique to Namibia): agulhensis (Barnard, 1927), coffer (Gunther, 1874), gilchristi (Boulenger, 1900), nalalensis (Gunther, 1874), nudiceps (Valenciennes, 1837), and saldanha (Barnard, 1927). Some of them are very similar to each other. In most species extreme variability in the colour patterns and in meristic counts was found. C. gilchristi is considered here as a valid species and a senior synonym of C. multifasciatus (Smith, 1959). A seventh species dubius (Smith, 1959) from the Seychelles is listed and briefly described.
- Full Text:
- Date Issued: 1996-09
- Authors: Goren, Menachem , J.L.B. Smith Institute of Ichthyology
- Date: 1996-09
- Subjects: Fishes -- South Africa , Gobiidae
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10962/70972 , vital:29766 , 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. 57 , The genus Caffrogobius Smitt, 1900 is composed of seven species. The members of the genus are moderate size gobies, reaching a length of 10-14 cm (SL). The species of the genus are characterized by a combination of the following characters: Cheek papillae pattern transverse; dorsal segmented rays: 9-14; anal segmented rays: 8-12; caudal segmented rays: 16-18; pectoral rays: 16-23. Scales along the body: 30-64; transverse rows of scales: 9-23; vertebrae: 27 (11+16 or 10+17); formula of fin pterygiophores: 3-22110. Six species of Caffrogobius are found around the southern part of the African continent (Mozambique to Namibia): agulhensis (Barnard, 1927), coffer (Gunther, 1874), gilchristi (Boulenger, 1900), nalalensis (Gunther, 1874), nudiceps (Valenciennes, 1837), and saldanha (Barnard, 1927). Some of them are very similar to each other. In most species extreme variability in the colour patterns and in meristic counts was found. C. gilchristi is considered here as a valid species and a senior synonym of C. multifasciatus (Smith, 1959). A seventh species dubius (Smith, 1959) from the Seychelles is listed and briefly described.
- Full Text:
- Date Issued: 1996-09
The taxonomy and life-history of Argyrosomus japonicus and A. inodorus, two important sciaenids off the South African coast
- Authors: Griffiths, Marc H
- Date: 1996
- Subjects: Argyrosomus Sciaenidae -- South Africa Sciaenidae -- Namibia
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5323 , http://hdl.handle.net/10962/d1005169
- Description: A study of the biology, anatomy and taxonomy of the sciaenid fishes of the genus Argyrosomus from South Africa and Namibia revealed that three species were confused under the name "Argyrosomus Izololepidotus (Lacepède 1801)". Comparison of morphometric and meristic data, otoliths, swim-bladders, drumming muscles, and other morphological features of specimens from southern Africa, Madagascar, the Mediterranean, the eastern Atlantic Ocean, Japan and Australia, revealed that "A. hololepidotus" is a complex of four species: A. japonicus (Temminck & Schlegel 1843), which occurs off southern Africa, Japan and Australia; A. inodorus sp. nov., which is known from Namibia to the Kei River (32°40'S) on the east coast of South Africa; A. coronus sp. nov., which is known from central and northern Namibia and Angola, and A. hololepidotus, which appears to be endemic to Madagascar. Both A. japonicus and A. inodorus are important recreational and commercial linefish species in South Africa. Although A. inodorus occurs on the east and west coasts of South Africa, and A. japonicus is found between Cape Point and Mozambique, the former species is abundant only between Cape Point and the Kei River, and the latter species from Cape Agulhas to northern KwaZulu/Natal. The life-histories of Argyrosomus japonicus and A. inodorus, within these respective ranges, were elucidated using length-at-age, reproductive, catch and effort, size composition, otolith dimension/fish length and tagging data. Median sizes at maturity (L₅₀) for A. japonicus were 920 mm TL (5 years) for males and 1070 mm TL (6 years) for females. All males >1100 mm TL (7 years) and all females >1200 mm TL (8 years) were mature. Females grew faster than males, but in both sexes growth slowed dramatically after maturity. Maximum age recorded was 42 years, but fish older than 27 years were rare. Adult A. japonicus were predominantly found in the nearshore marine environment, but also occurred in estuaries and in the surf zone. Spawning takes place in the nearshore environment, from August to November in Natal, and from October to January in the Southern and South-Eastern Cape regions. A large proportion of the adult population migrate to Natal to spawn, although spawning may continue once they return to the Cape. Early juveniles of 20-30 mm TL recruit into turbid estuaries along the entire east coast, possibly aided by olfactory cues. They appear to remain in the upper reaches of the estuaries where they find suitable food and refuge from predators until they grow to about 150 mm TL. Juveniles larger than this size were found in the middle and lower reaches of estuaries and also in the surf zone. Juvenile A. japonicus (<1000 mm TL) generally did not migrate long distances, but remained as separate sub-stocks until they reached maturity. A. inodorus grows more slowly than A. japonicus, and attains a lower maximum age (25 years) and a smaller maximum size (34 vs 75 kg). There was no significant difference between the growth rates of male and female A. inodorus. Those in the South-Westem Cape initially grew faster than those on the east coast, but growth slowed sooner in the former region with the result that these fish attained a smaller maximum size. Although ripe A. inodorus were sampled throughout the year, there was a distinct spawning season from August to December, with a peak in spring (Sept-Nov). Spawning occurred throughout the study area for this species, in <50 m depth. Size at sexual maturity for A. inodorus was smaller in the South-Eastern Cape than in the Southern Cape. Median size at maturity for females was attained at 310 mm TL (1.3 years) in the former and at 375 mm TL (2.4 years) in the latter region, and the length at which all females were mature was 400 mm (3.5 years) and 550 mm (4.7 years) respectively. For males the estimates of Lso and total maturity were 200 mm (1 year) and 400 mm (2.8 years) for the SouthEastern Cape and 250 mm (1.5 years) and 450 mm (3.4 years) in the Southern Cape. East of Cape Agulhas, A. inodorus was found from just beyond the surf zone to depths of 120 m. Adults occurred predominantly on reef (>20 m) while juveniles were found mainly over soft substrata of sand/mud (5-120 m depth). Early juveniles do not enter estuaries, but apparently recruit to nursery areas immediately beyond the backline of breakers (5-10 m depth), and then move seawards with growth. No juveniles were obtained from the area west of Cape Agulhas as substrates <200 m depth were unsuitable for trawling. Due to lower water temperatures, the adults in this area were found from within the surf zone to depths of only 20 m. East and west of Cape Agulhas there was evidence of offshore dispersal in winter, in response to oceanographic changes. Based upon otolith morphology, juvenile and adult distribution patterns, sizes at sexual maturity and on tagging data, A. inodorus between Cape Point and the Kei River apparently exist as three separate stocks, one in the South-Eastern Cape, one in the Southern Cape and one in the South-Western Cape, with limited exchange. The life-histories of A. japonicus and A. inodorus are discussed in terms of their management. The large size at maturity of A. japonicus together with evidence for considerable human impact on the early juvenile, juvenile, and the adult phases of the life-cycle indicate that estuarine nursery habitats need to be conserved, that the minimum size limit should be increased, and that current bag limits for this species should be reviewed. Although the current minimum size limit provides protection for A. illodorus until maturity, evidence is presented which indicates that at least one and possibly all of the stocks of this species are currently over-exploited. Stock assessment of the South African A. japonicus and A. inodorus resources, and the implementation of effective management strategies, are therefore a matter of urgency.
- Full Text:
- Date Issued: 1996
- Authors: Griffiths, Marc H
- Date: 1996
- Subjects: Argyrosomus Sciaenidae -- South Africa Sciaenidae -- Namibia
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5323 , http://hdl.handle.net/10962/d1005169
- Description: A study of the biology, anatomy and taxonomy of the sciaenid fishes of the genus Argyrosomus from South Africa and Namibia revealed that three species were confused under the name "Argyrosomus Izololepidotus (Lacepède 1801)". Comparison of morphometric and meristic data, otoliths, swim-bladders, drumming muscles, and other morphological features of specimens from southern Africa, Madagascar, the Mediterranean, the eastern Atlantic Ocean, Japan and Australia, revealed that "A. hololepidotus" is a complex of four species: A. japonicus (Temminck & Schlegel 1843), which occurs off southern Africa, Japan and Australia; A. inodorus sp. nov., which is known from Namibia to the Kei River (32°40'S) on the east coast of South Africa; A. coronus sp. nov., which is known from central and northern Namibia and Angola, and A. hololepidotus, which appears to be endemic to Madagascar. Both A. japonicus and A. inodorus are important recreational and commercial linefish species in South Africa. Although A. inodorus occurs on the east and west coasts of South Africa, and A. japonicus is found between Cape Point and Mozambique, the former species is abundant only between Cape Point and the Kei River, and the latter species from Cape Agulhas to northern KwaZulu/Natal. The life-histories of Argyrosomus japonicus and A. inodorus, within these respective ranges, were elucidated using length-at-age, reproductive, catch and effort, size composition, otolith dimension/fish length and tagging data. Median sizes at maturity (L₅₀) for A. japonicus were 920 mm TL (5 years) for males and 1070 mm TL (6 years) for females. All males >1100 mm TL (7 years) and all females >1200 mm TL (8 years) were mature. Females grew faster than males, but in both sexes growth slowed dramatically after maturity. Maximum age recorded was 42 years, but fish older than 27 years were rare. Adult A. japonicus were predominantly found in the nearshore marine environment, but also occurred in estuaries and in the surf zone. Spawning takes place in the nearshore environment, from August to November in Natal, and from October to January in the Southern and South-Eastern Cape regions. A large proportion of the adult population migrate to Natal to spawn, although spawning may continue once they return to the Cape. Early juveniles of 20-30 mm TL recruit into turbid estuaries along the entire east coast, possibly aided by olfactory cues. They appear to remain in the upper reaches of the estuaries where they find suitable food and refuge from predators until they grow to about 150 mm TL. Juveniles larger than this size were found in the middle and lower reaches of estuaries and also in the surf zone. Juvenile A. japonicus (<1000 mm TL) generally did not migrate long distances, but remained as separate sub-stocks until they reached maturity. A. inodorus grows more slowly than A. japonicus, and attains a lower maximum age (25 years) and a smaller maximum size (34 vs 75 kg). There was no significant difference between the growth rates of male and female A. inodorus. Those in the South-Westem Cape initially grew faster than those on the east coast, but growth slowed sooner in the former region with the result that these fish attained a smaller maximum size. Although ripe A. inodorus were sampled throughout the year, there was a distinct spawning season from August to December, with a peak in spring (Sept-Nov). Spawning occurred throughout the study area for this species, in <50 m depth. Size at sexual maturity for A. inodorus was smaller in the South-Eastern Cape than in the Southern Cape. Median size at maturity for females was attained at 310 mm TL (1.3 years) in the former and at 375 mm TL (2.4 years) in the latter region, and the length at which all females were mature was 400 mm (3.5 years) and 550 mm (4.7 years) respectively. For males the estimates of Lso and total maturity were 200 mm (1 year) and 400 mm (2.8 years) for the SouthEastern Cape and 250 mm (1.5 years) and 450 mm (3.4 years) in the Southern Cape. East of Cape Agulhas, A. inodorus was found from just beyond the surf zone to depths of 120 m. Adults occurred predominantly on reef (>20 m) while juveniles were found mainly over soft substrata of sand/mud (5-120 m depth). Early juveniles do not enter estuaries, but apparently recruit to nursery areas immediately beyond the backline of breakers (5-10 m depth), and then move seawards with growth. No juveniles were obtained from the area west of Cape Agulhas as substrates <200 m depth were unsuitable for trawling. Due to lower water temperatures, the adults in this area were found from within the surf zone to depths of only 20 m. East and west of Cape Agulhas there was evidence of offshore dispersal in winter, in response to oceanographic changes. Based upon otolith morphology, juvenile and adult distribution patterns, sizes at sexual maturity and on tagging data, A. inodorus between Cape Point and the Kei River apparently exist as three separate stocks, one in the South-Eastern Cape, one in the Southern Cape and one in the South-Western Cape, with limited exchange. The life-histories of A. japonicus and A. inodorus are discussed in terms of their management. The large size at maturity of A. japonicus together with evidence for considerable human impact on the early juvenile, juvenile, and the adult phases of the life-cycle indicate that estuarine nursery habitats need to be conserved, that the minimum size limit should be increased, and that current bag limits for this species should be reviewed. Although the current minimum size limit provides protection for A. illodorus until maturity, evidence is presented which indicates that at least one and possibly all of the stocks of this species are currently over-exploited. Stock assessment of the South African A. japonicus and A. inodorus resources, and the implementation of effective management strategies, are therefore a matter of urgency.
- Full Text:
- Date Issued: 1996
The influence of oceanographic conditions and culture methods on the dynamics of mussel farming in Saldanha Bay, South Africa
- Authors: Heasman, Kevin Gerald
- Date: 1996
- Subjects: Mytilidae -- South Africa , Mussel culture -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5290 , http://hdl.handle.net/10962/d1005134 , Mytilidae -- South Africa , Mussel culture -- South Africa
- Description: The principal aim of this study was to establish the biological and environmental parameters governing the successful and sustainable cultivation of mussels in Saldanha Bay. The environmental study investigated seston, chlorophyll-a and particulate organic matter (POM) levels, water temperature dissolved oxygen and salinity levels in the bay and water flow in and around the rafts. The biological part of the study investigated the efficiency of food extraction, growth rates, mussel condition, fouling and production and yield on a rope, raft and farm scale. Saldanha Bay is well suited for the culture of mussels, particularly Mytilus galloprovincialis and Choromytilus meridionalis. Water temperature and salinity in Saldanha Bay were found to be near optimal for mussel culture. POM and chlorophyll-a levels were found to be high due to primary production resulting from the nutrient rich upwelled water outside Saldanha Bay. The mean levels of chlorophyll-a (8,6μg/l) represent 6%, by mass, of the total POM. On a bay scale the POM remained above the mussels maximum requirements (pseudofaeces threshold) during the study period. Mussels showed a preference for the phytoplankton portion of the POM. Approximately 40% of the chlorophyll-a was extracted from the water by the mussel farm. The efficiency of food extraction increased with mussel age. Rafts with seed mussels younger than 2 months, 3 to 4 months, 5 to 6 months and older than 6 months extracted 32%, 55%, 85% and 92% of the available chlorophyll-a respectively. An increase of rope spacing on the rafts resulted in 37% more chlorophyll-a and 30% more particle volume reaching the lee of the raft. Ambient water currents in the bay show flow rates of up to 22cm per second. However, on entering a raft with a rope spacing of 60cm, the water flow is attenuated by 90%. Increasing the rope spacing to 90cm resulted in a water flow attenuation of 72%. The increase in rope spacing ensures that the mussels in the centre of the raft are feeding on food levels close to, or above, the pseudofaeces level. Mussel growth rate at a rope spacing of 90cm is significantly improved as a result of the increased food delivery. There are other factors, however that effect mussel growth. Growth rates were found to be better in summer than in winter. The reduced winter growth rate is possibly due to competition with the maturing fouling organisms which settle in mid to late summer. Fouling by mussel spat and Ciona intestinalis is seasonal, occurring from December to May. C.intestinalis is prevalent in the centre of the farm and rafts as low energy waters are preferred by this species. Mussel spat settles mainly on the periphery of the farm and the rafts. Competition with fouling organisms reduces growth and increases mortality of the cultured mussels. Results indicate that the present spacing of rafts, (1 raft per hectare) is adequate under existing conditions. Any new farms should maintain batches of 50 rafts with channels between them to ensure water current penetration into the furthest reaches of the farm. Rope spacing on the rafts should be increased to between 60cm and 90cm. Mussel density should be regulated according to mussel size and fouling should be controlled to maintain yields.
- Full Text:
- Date Issued: 1996
- Authors: Heasman, Kevin Gerald
- Date: 1996
- Subjects: Mytilidae -- South Africa , Mussel culture -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5290 , http://hdl.handle.net/10962/d1005134 , Mytilidae -- South Africa , Mussel culture -- South Africa
- Description: The principal aim of this study was to establish the biological and environmental parameters governing the successful and sustainable cultivation of mussels in Saldanha Bay. The environmental study investigated seston, chlorophyll-a and particulate organic matter (POM) levels, water temperature dissolved oxygen and salinity levels in the bay and water flow in and around the rafts. The biological part of the study investigated the efficiency of food extraction, growth rates, mussel condition, fouling and production and yield on a rope, raft and farm scale. Saldanha Bay is well suited for the culture of mussels, particularly Mytilus galloprovincialis and Choromytilus meridionalis. Water temperature and salinity in Saldanha Bay were found to be near optimal for mussel culture. POM and chlorophyll-a levels were found to be high due to primary production resulting from the nutrient rich upwelled water outside Saldanha Bay. The mean levels of chlorophyll-a (8,6μg/l) represent 6%, by mass, of the total POM. On a bay scale the POM remained above the mussels maximum requirements (pseudofaeces threshold) during the study period. Mussels showed a preference for the phytoplankton portion of the POM. Approximately 40% of the chlorophyll-a was extracted from the water by the mussel farm. The efficiency of food extraction increased with mussel age. Rafts with seed mussels younger than 2 months, 3 to 4 months, 5 to 6 months and older than 6 months extracted 32%, 55%, 85% and 92% of the available chlorophyll-a respectively. An increase of rope spacing on the rafts resulted in 37% more chlorophyll-a and 30% more particle volume reaching the lee of the raft. Ambient water currents in the bay show flow rates of up to 22cm per second. However, on entering a raft with a rope spacing of 60cm, the water flow is attenuated by 90%. Increasing the rope spacing to 90cm resulted in a water flow attenuation of 72%. The increase in rope spacing ensures that the mussels in the centre of the raft are feeding on food levels close to, or above, the pseudofaeces level. Mussel growth rate at a rope spacing of 90cm is significantly improved as a result of the increased food delivery. There are other factors, however that effect mussel growth. Growth rates were found to be better in summer than in winter. The reduced winter growth rate is possibly due to competition with the maturing fouling organisms which settle in mid to late summer. Fouling by mussel spat and Ciona intestinalis is seasonal, occurring from December to May. C.intestinalis is prevalent in the centre of the farm and rafts as low energy waters are preferred by this species. Mussel spat settles mainly on the periphery of the farm and the rafts. Competition with fouling organisms reduces growth and increases mortality of the cultured mussels. Results indicate that the present spacing of rafts, (1 raft per hectare) is adequate under existing conditions. Any new farms should maintain batches of 50 rafts with channels between them to ensure water current penetration into the furthest reaches of the farm. Rope spacing on the rafts should be increased to between 60cm and 90cm. Mussel density should be regulated according to mussel size and fouling should be controlled to maintain yields.
- Full Text:
- Date Issued: 1996
The alternative press in Namibia, 1960-1990
- Authors: Heuva, William Edward
- Date: 1996
- Subjects: Press -- Namibia , Press and politics -- Namibia , Namibia -- Newspapers
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3434 , http://hdl.handle.net/10962/d1002888 , Press -- Namibia , Press and politics -- Namibia , Namibia -- Newspapers
- Description: The study seeks to document the development of the alternative press in Namibia from 1960 to 1990. It traces the reasons for its emergence and outlines the stated aims and objectives in order to illustrate its attempts to nurture a culture - of colonial resistance. It is argued that structural factors such as funding, distribution, advertisements and ownership enabled the alternative press to operate outside the South African apartheid hegemony. The study explains how the intellectuals used the alternative press in their attempts to mobilise and organise colonised Namibians for social change. They did this by formulating and disseminating ideologically constructed discourses (messages) which challenged the colonial discourse. These messages were produced and directed towards a specific audience, the masses to whom the intellectuals were organically linked. Their primary news definers were also drawn from the ranks of these masses. It is further argued that the alternative press came to represent the colonised masses by voicing their needs and aspirations which were marginalised by the mainstream colonial media. Finally, a relatively detailed analysis of the content, the language used and the'messages carried by the alternative press has been made to demonstrate its political agenda, which was to empower the masses to achieve their objective - the attainment of political independence. These issues are analyzed against a background of theoretical frameworks which seek to explain how subordinated groups and classes in a state of domination sought to establish alternative channels of communication in the creation of a counter hegemonic order.
- Full Text:
- Date Issued: 1996
- Authors: Heuva, William Edward
- Date: 1996
- Subjects: Press -- Namibia , Press and politics -- Namibia , Namibia -- Newspapers
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3434 , http://hdl.handle.net/10962/d1002888 , Press -- Namibia , Press and politics -- Namibia , Namibia -- Newspapers
- Description: The study seeks to document the development of the alternative press in Namibia from 1960 to 1990. It traces the reasons for its emergence and outlines the stated aims and objectives in order to illustrate its attempts to nurture a culture - of colonial resistance. It is argued that structural factors such as funding, distribution, advertisements and ownership enabled the alternative press to operate outside the South African apartheid hegemony. The study explains how the intellectuals used the alternative press in their attempts to mobilise and organise colonised Namibians for social change. They did this by formulating and disseminating ideologically constructed discourses (messages) which challenged the colonial discourse. These messages were produced and directed towards a specific audience, the masses to whom the intellectuals were organically linked. Their primary news definers were also drawn from the ranks of these masses. It is further argued that the alternative press came to represent the colonised masses by voicing their needs and aspirations which were marginalised by the mainstream colonial media. Finally, a relatively detailed analysis of the content, the language used and the'messages carried by the alternative press has been made to demonstrate its political agenda, which was to empower the masses to achieve their objective - the attainment of political independence. These issues are analyzed against a background of theoretical frameworks which seek to explain how subordinated groups and classes in a state of domination sought to establish alternative channels of communication in the creation of a counter hegemonic order.
- Full Text:
- Date Issued: 1996
L'image du peuple dans Le premier homme d'Albert Camus
- Heynderickx, Nathalie Marcel Madeleine
- Authors: Heynderickx, Nathalie Marcel Madeleine
- Date: 1996
- Subjects: Camus, Albert, 1913-1960. Premier homme
- Language: French
- Type: Thesis , Masters , MA
- Identifier: vital:3577 , http://hdl.handle.net/10962/d1002150 , Camus, Albert, 1913-1960. Premier homme
- Full Text:
- Date Issued: 1996
- Authors: Heynderickx, Nathalie Marcel Madeleine
- Date: 1996
- Subjects: Camus, Albert, 1913-1960. Premier homme
- Language: French
- Type: Thesis , Masters , MA
- Identifier: vital:3577 , http://hdl.handle.net/10962/d1002150 , Camus, Albert, 1913-1960. Premier homme
- Full Text:
- Date Issued: 1996
Marine algal remains from the Upper Devonian of South Africa
- Hiller, Norton, Gess, Robert W
- Authors: Hiller, Norton , Gess, Robert W
- Date: 1996
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/72753 , vital:30107 , https://doi.org/10.1016/0034-6667(95)00062-3
- Description: The remains of what are interpreted to be marine brown algae are described from Late Devonian clastic rocks in South Africa. Dichotomously-branched specimens with rounded terminations are placed in the new species Hungerfordia fionae and the closely related H. dichotoma Fry and Banks is placed in synonymy with Buthotrephis trichotoma Douglas and Jell. A large strap-like form is described as a new species, Yeaia africana.
- Full Text: false
- Date Issued: 1996
- Authors: Hiller, Norton , Gess, Robert W
- Date: 1996
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/72753 , vital:30107 , https://doi.org/10.1016/0034-6667(95)00062-3
- Description: The remains of what are interpreted to be marine brown algae are described from Late Devonian clastic rocks in South Africa. Dichotomously-branched specimens with rounded terminations are placed in the new species Hungerfordia fionae and the closely related H. dichotoma Fry and Banks is placed in synonymy with Buthotrephis trichotoma Douglas and Jell. A large strap-like form is described as a new species, Yeaia africana.
- Full Text: false
- Date Issued: 1996
A pilot study of secondary teachers' understanding of population dynamics
- Authors: Hockey, Athol James Temlett
- Date: 1996
- Subjects: Environmental education -- South Africa , Population -- Study and teaching (Secondary) -- South Africa
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1703 , http://hdl.handle.net/10962/d1003586
- Description: Population dynamics is a South African secondary school biology syllabus topic which deals specifically with ecology or concepts within the realm of ecology. It is currently taught in a way which largely emphasises the teaching and learning of facts and concepts, often out of any context to which students can relate. While it is important to convey scientific concepts, it is just as important to address social and political issues regarding overpopulation and the environment. This research involved the administration of a questionnaire to Std 10 biology teachers in the Department of Education and Training (DET), which sought to obtain information about various aspects of teachers' teaching of population dynamics. These included their feelings toward the teaching of the specific sections of the population dynamics syllabus, and their knowledge and views of environmental issues and human population expansion. The findings of the research suggest that population dynamics is an important topic for students to learn about. The traditional teacher-centred approach to teaching is used by the teachers in the research sample. The sections considered by the teachers to be most important for learning were also considered the most interesting and the easiest to teach. The majority of the teachers in the research sample recognised that human population growth is a global and local problem and that South Africa cannot sustain its present population growth. The teachers in the sample show a diversity of opinions about sustainable development, and have a limited understanding of the links between population, poverty and consumption. Important information gained from the research will be significant in the development of a teaching and learning module on population dynamics that reflects the aims and purpose of environmental education.
- Full Text:
- Date Issued: 1996
- Authors: Hockey, Athol James Temlett
- Date: 1996
- Subjects: Environmental education -- South Africa , Population -- Study and teaching (Secondary) -- South Africa
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1703 , http://hdl.handle.net/10962/d1003586
- Description: Population dynamics is a South African secondary school biology syllabus topic which deals specifically with ecology or concepts within the realm of ecology. It is currently taught in a way which largely emphasises the teaching and learning of facts and concepts, often out of any context to which students can relate. While it is important to convey scientific concepts, it is just as important to address social and political issues regarding overpopulation and the environment. This research involved the administration of a questionnaire to Std 10 biology teachers in the Department of Education and Training (DET), which sought to obtain information about various aspects of teachers' teaching of population dynamics. These included their feelings toward the teaching of the specific sections of the population dynamics syllabus, and their knowledge and views of environmental issues and human population expansion. The findings of the research suggest that population dynamics is an important topic for students to learn about. The traditional teacher-centred approach to teaching is used by the teachers in the research sample. The sections considered by the teachers to be most important for learning were also considered the most interesting and the easiest to teach. The majority of the teachers in the research sample recognised that human population growth is a global and local problem and that South Africa cannot sustain its present population growth. The teachers in the sample show a diversity of opinions about sustainable development, and have a limited understanding of the links between population, poverty and consumption. Important information gained from the research will be significant in the development of a teaching and learning module on population dynamics that reflects the aims and purpose of environmental education.
- Full Text:
- Date Issued: 1996
The significance of trade policy in promoting the international competitiveness of South African industry
- Authors: Hofmeyr, Lynne Mary
- Date: 1996
- Subjects: South Africa -- Commerce , South Africa -- Commercial policy , International trade
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2781 , http://hdl.handle.net/10962/d1002991 , South Africa -- Commerce , South Africa -- Commercial policy , International trade
- Description: This study proposes to examme the significance of trade policy in promoting the international competitiveness of South African industry during the period from the early 1970s up until the present day. By providing a background of South Africa's past trade policies, it is argued that the origins of South Africa's low levels of competitiveness essentially lie in the apartheid years where trade policies were not linked to the attainment of international competitiveness and improved productivity. The study then reviews the development of South Africa's trade policies in the 1990s. In so doing, it reveals weaknesses in the areas of implementation which are critiqued in greater detail by using the clothing and textile industries as a case study, and other selected examples. The study finally concludes that trade policy is crucial to global competitiveness and that it is the responsibility of all parties concerned to ensure that trade policies enhance and not inhibit competitiveness.
- Full Text:
- Date Issued: 1996
- Authors: Hofmeyr, Lynne Mary
- Date: 1996
- Subjects: South Africa -- Commerce , South Africa -- Commercial policy , International trade
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2781 , http://hdl.handle.net/10962/d1002991 , South Africa -- Commerce , South Africa -- Commercial policy , International trade
- Description: This study proposes to examme the significance of trade policy in promoting the international competitiveness of South African industry during the period from the early 1970s up until the present day. By providing a background of South Africa's past trade policies, it is argued that the origins of South Africa's low levels of competitiveness essentially lie in the apartheid years where trade policies were not linked to the attainment of international competitiveness and improved productivity. The study then reviews the development of South Africa's trade policies in the 1990s. In so doing, it reveals weaknesses in the areas of implementation which are critiqued in greater detail by using the clothing and textile industries as a case study, and other selected examples. The study finally concludes that trade policy is crucial to global competitiveness and that it is the responsibility of all parties concerned to ensure that trade policies enhance and not inhibit competitiveness.
- Full Text:
- Date Issued: 1996