An unusual new fossil shark (Pisces: Chondrichthyes) from the Late Devonian of South Africa
- Anderson, M Eric, Long, John A, Gess, Robert W, Hiller, Norton
- Authors: Anderson, M Eric , Long, John A , Gess, Robert W , Hiller, Norton
- Date: 1999
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/73910 , vital:30240 , http://museum.wa.gov.au/sites/default/files/10. Anderson, Long, Gess, Hiller.pdf
- Description: A new stem-group chondrichthyan fish, PlesioselacJllIs macracanthlls gen. et sp. nov., is described from the Late Devonian Witpoort Formation, representing an estuarine lagoon site, near Grahamstown, South Africa. Based on a single, fairly complete specimen, it is distinctive in its a single dorsal fin braced by a large, stout spine with numerous ribs and posterior denticles, apparently no second dorsal or anal fin, an amphistylic jaw suspension, and a distinctive triangular palatoquadrate. It is suggested that the species may represent a high-latitude, Late Devonian relict taxon.
- Full Text:
- Authors: Anderson, M Eric , Long, John A , Gess, Robert W , Hiller, Norton
- Date: 1999
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/73910 , vital:30240 , http://museum.wa.gov.au/sites/default/files/10. Anderson, Long, Gess, Hiller.pdf
- Description: A new stem-group chondrichthyan fish, PlesioselacJllIs macracanthlls gen. et sp. nov., is described from the Late Devonian Witpoort Formation, representing an estuarine lagoon site, near Grahamstown, South Africa. Based on a single, fairly complete specimen, it is distinctive in its a single dorsal fin braced by a large, stout spine with numerous ribs and posterior denticles, apparently no second dorsal or anal fin, an amphistylic jaw suspension, and a distinctive triangular palatoquadrate. It is suggested that the species may represent a high-latitude, Late Devonian relict taxon.
- Full Text:
Analysis of chromameter results obtained from corticosteroid-induced skin blanching assay: comparison of visual and chromameter data
- Schwarb, Fabian P, Smith, Eric W, Haigh, John M, Surber, Christian
- Authors: Schwarb, Fabian P , Smith, Eric W , Haigh, John M , Surber, Christian
- Date: 1999
- Language: English
- Type: text , Article
- Identifier: vital:6426 , http://hdl.handle.net/10962/d1006562
- Description: In a Guidance document, the American FDA recommends the use of a Minolta chromameter rather than the human eye for the quantitative assessment of the pharmacodynamic blanching response produced by topical application of corticosteroids. The purpose of this study was to compare the appropriateness of the human eye and two models of chromameter for the estimation of skin blanching, in terms of the quality of the data generated by each method. The corticosteroid-induced skin blanching from four different betamethasone 17-valerate cream formulations was compared in a typical human skin blanching trial. The optimized assay methodology routinely practised in our laboratories was utilized. The blanching responses were assessed visually by three trained, independent observers and recorded by two chromameters (Minolta model CR-200 and model CR-300). The topical availability of the four creams was determined using visual scoring and chromameter measurements. All data were manipulated in such a manner as to produce a blanching response versus time profile from which AUBC analysis could be performed. Good correlation was observed between the visual assessments made by three independent observers. In contrast, moderate correlation was determined between visual, CR-200 and CR-300 measurements. Surprisingly, no direct linear relationship between the AUBCs produced by the two chromameters was observed indicating that the quality of the data obtained from the two instruments may not be equal. This investigation also indicated that the use of the chromameter is not completely objective. Visual scoring and chromameter measurement produce data sets that differ in quality. Each procedure needs to be validated and investigators have to be trained for both visual assessment and the operation of the chromameter, particularly with regard to the manipulation of the measuring head of the instrument.
- Full Text:
- Authors: Schwarb, Fabian P , Smith, Eric W , Haigh, John M , Surber, Christian
- Date: 1999
- Language: English
- Type: text , Article
- Identifier: vital:6426 , http://hdl.handle.net/10962/d1006562
- Description: In a Guidance document, the American FDA recommends the use of a Minolta chromameter rather than the human eye for the quantitative assessment of the pharmacodynamic blanching response produced by topical application of corticosteroids. The purpose of this study was to compare the appropriateness of the human eye and two models of chromameter for the estimation of skin blanching, in terms of the quality of the data generated by each method. The corticosteroid-induced skin blanching from four different betamethasone 17-valerate cream formulations was compared in a typical human skin blanching trial. The optimized assay methodology routinely practised in our laboratories was utilized. The blanching responses were assessed visually by three trained, independent observers and recorded by two chromameters (Minolta model CR-200 and model CR-300). The topical availability of the four creams was determined using visual scoring and chromameter measurements. All data were manipulated in such a manner as to produce a blanching response versus time profile from which AUBC analysis could be performed. Good correlation was observed between the visual assessments made by three independent observers. In contrast, moderate correlation was determined between visual, CR-200 and CR-300 measurements. Surprisingly, no direct linear relationship between the AUBCs produced by the two chromameters was observed indicating that the quality of the data obtained from the two instruments may not be equal. This investigation also indicated that the use of the chromameter is not completely objective. Visual scoring and chromameter measurement produce data sets that differ in quality. Each procedure needs to be validated and investigators have to be trained for both visual assessment and the operation of the chromameter, particularly with regard to the manipulation of the measuring head of the instrument.
- Full Text:
Anting in Afrotropical birds: a review
- Authors: Craig, Adrian J F K
- Date: 1999
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/447746 , vital:74671 , https://doi.org/10.1080/00306525.1999.9634237
- Description: Passive anting has been recorded from four non-passerine species in Africa, the Rock Kestrel Falco tinnunculus, the African Finfoot Podica senegalensis, the African Hoopoe Upupa epops and the Whitebacked Mousebird Colius colius. Active or passive anting has been recorded from 21 passerine species in 10 families in the wild, and in captive birds in a further 27 species of 3 families. Although such behaviour may have been overlooked or misinterpreted, the rarity of observations implies that in most species anting is likely to be infrequent. In all cases in which the ants have been identified, they were members of the sub-family Formicinae. It appears unlikely that any single functional explanation can account for the observed occurrences of this behaviour.
- Full Text:
- Authors: Craig, Adrian J F K
- Date: 1999
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/447746 , vital:74671 , https://doi.org/10.1080/00306525.1999.9634237
- Description: Passive anting has been recorded from four non-passerine species in Africa, the Rock Kestrel Falco tinnunculus, the African Finfoot Podica senegalensis, the African Hoopoe Upupa epops and the Whitebacked Mousebird Colius colius. Active or passive anting has been recorded from 21 passerine species in 10 families in the wild, and in captive birds in a further 27 species of 3 families. Although such behaviour may have been overlooked or misinterpreted, the rarity of observations implies that in most species anting is likely to be infrequent. In all cases in which the ants have been identified, they were members of the sub-family Formicinae. It appears unlikely that any single functional explanation can account for the observed occurrences of this behaviour.
- Full Text:
Aspects of condition in captive and free-ranging dolphins
- Authors: Young, Deborah Dione
- Date: 1999
- Subjects: Dolphins -- Physiology Dolphins -- Behavior
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5799 , http://hdl.handle.net/10962/d1006117
- Description: Aspects of morphological and physiological condition of captive and net-caught dolphins were studied with respect to age, diet, reproduction and seasonal changes in environmental factors. These investigations aimed to provide base-line data on marine mammal physiological and morphological condition indices and to expand the knowledge of condition assessment of small cetaceans. By examining the interactive nature of animal condition and growth, diet and the environment, the study investigated the potential usefulness of animal condition indices to assess and monitor habitat quality. Base-line values for haematological and blood chemistry parameters were established for five captive bottlenose dolphins (Tursiops truncatus), using monthly blood samples, collected between 1992 and 1995, and corresponding measures of body weight and blubber thickness; feeding, dietary energy intake, water temperature and behavioural and medical records. Curves of best fit were used to interpret trends between leukocytic, haematological and blood chemistry parameters and morphology, diet and water temperature. WBC's and WBC differential cell types were related more distinctly to clinical changes in health, than to condition. RBC, HB and PCV were useful as short-term indicators of nutritional condition, with enhanced haematological status associated with greater food intake and improved diet quality. Weight was a more effective long-term indicator of nutritional status. The importance of blubber thickness measurements as a morphological index of condition was reinforced, with relationships between blubber thickness and haematology highlighting interactions between morphological and physiological condition. The complex interactions between haematology, diet, temperature and weight emphasised the need to account for all influential factors when considering haematological condition. The blood chemistry parameters of serum creatinine, BUN, BUN:creatinine and serum albumin provided the best indication of nutritional condition and diet quality in captive dolphins. Creatinine and BUN:creatinine also reflected changes in morphological condition. Reduced ALP was associated with nutritional stress but was more effectively used as an indication of metabolism and growth activity. LDH and CPK were highly variable and fluctuated with changing activity levels, limiting their use as condition indices. Serum sodium was an important indication of diet quality and hydration status. Many of these parameters effectively illustrated that physiological condition is compromised outside of the thermoneutral zone of the species. Bottlenose and common (Delphinus delphis) dolphins, incidentally caught in shark nets, were used to investigate the condition of free-ranging dolphins. Blood samples, taken as soon as possible after capture from drowned animals, were used to analyse physiological parameters. Dissections provided morphological data. Age and dietary status were assessed using growth layer groups in teeth and stomach content analyses, respectively. Morphological measures of net-caught dolphins reflected important interactions with diet, water temperature and reproductive status. Weight, girth and blubber thickness were valuable indicators of condition, although blubber thickness and proportional blubber weight were the best indicators of nutritional status. Condition of net-caught dolphins was difficult to assess in terms of leukocytic and haematological parameters. Stress- and post-mortem-associated changes, and variable data, reduced the usefulness of some parameters. WBC counts reflected on immunological status and served to emphasise changes in health, which may lead to deterioration in condition. WBC's showed potential as indicators of habitat quality, in terms of parasite load and/or pollution. Interactions between RBC, HB, PCV, MCV and dietary, morphological and environmental factors proved valuable in the short-term. Several haematological parameters were related to morphological condition, with weight, girth and blubber thickness, showing potential as non-invasive predictors of haematological status. Relationships between haematology and water temperature implied that dolphins have physiological and environmental "zones of comfort", within which condition is optimised. LDH and CPK were elevated by capture stress and post-mortem changes. Serum sodium and plasma glucose were good indicators of short-term nutritional status, but were altered by stress, which reduced their usefulness as condition indicators. BUN, albumin, globulin, albumin:globulin, total cholesterol and triglycerides appeared to be little affected by these changes and are potentially valuable indicators of condition in net-caught and/or free-ranging dolphins, particularly with respect to nutritional condition, and associated changes in morphology. Although data were limited, these parameters show the greatest potential as physiological indicators of animal condition and environmental health. The limitations of this study are recognised, however, results highlight the feasibility of using net-caught specimens to monitor the condition of free-ranging marine mammals, and the marine habitat as a whole. Relationships established in this study will be used to elucidate further on the interactive nature of marine mammal condition and aid in the development of a non-invasive condition assessment technique.
- Full Text:
- Authors: Young, Deborah Dione
- Date: 1999
- Subjects: Dolphins -- Physiology Dolphins -- Behavior
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5799 , http://hdl.handle.net/10962/d1006117
- Description: Aspects of morphological and physiological condition of captive and net-caught dolphins were studied with respect to age, diet, reproduction and seasonal changes in environmental factors. These investigations aimed to provide base-line data on marine mammal physiological and morphological condition indices and to expand the knowledge of condition assessment of small cetaceans. By examining the interactive nature of animal condition and growth, diet and the environment, the study investigated the potential usefulness of animal condition indices to assess and monitor habitat quality. Base-line values for haematological and blood chemistry parameters were established for five captive bottlenose dolphins (Tursiops truncatus), using monthly blood samples, collected between 1992 and 1995, and corresponding measures of body weight and blubber thickness; feeding, dietary energy intake, water temperature and behavioural and medical records. Curves of best fit were used to interpret trends between leukocytic, haematological and blood chemistry parameters and morphology, diet and water temperature. WBC's and WBC differential cell types were related more distinctly to clinical changes in health, than to condition. RBC, HB and PCV were useful as short-term indicators of nutritional condition, with enhanced haematological status associated with greater food intake and improved diet quality. Weight was a more effective long-term indicator of nutritional status. The importance of blubber thickness measurements as a morphological index of condition was reinforced, with relationships between blubber thickness and haematology highlighting interactions between morphological and physiological condition. The complex interactions between haematology, diet, temperature and weight emphasised the need to account for all influential factors when considering haematological condition. The blood chemistry parameters of serum creatinine, BUN, BUN:creatinine and serum albumin provided the best indication of nutritional condition and diet quality in captive dolphins. Creatinine and BUN:creatinine also reflected changes in morphological condition. Reduced ALP was associated with nutritional stress but was more effectively used as an indication of metabolism and growth activity. LDH and CPK were highly variable and fluctuated with changing activity levels, limiting their use as condition indices. Serum sodium was an important indication of diet quality and hydration status. Many of these parameters effectively illustrated that physiological condition is compromised outside of the thermoneutral zone of the species. Bottlenose and common (Delphinus delphis) dolphins, incidentally caught in shark nets, were used to investigate the condition of free-ranging dolphins. Blood samples, taken as soon as possible after capture from drowned animals, were used to analyse physiological parameters. Dissections provided morphological data. Age and dietary status were assessed using growth layer groups in teeth and stomach content analyses, respectively. Morphological measures of net-caught dolphins reflected important interactions with diet, water temperature and reproductive status. Weight, girth and blubber thickness were valuable indicators of condition, although blubber thickness and proportional blubber weight were the best indicators of nutritional status. Condition of net-caught dolphins was difficult to assess in terms of leukocytic and haematological parameters. Stress- and post-mortem-associated changes, and variable data, reduced the usefulness of some parameters. WBC counts reflected on immunological status and served to emphasise changes in health, which may lead to deterioration in condition. WBC's showed potential as indicators of habitat quality, in terms of parasite load and/or pollution. Interactions between RBC, HB, PCV, MCV and dietary, morphological and environmental factors proved valuable in the short-term. Several haematological parameters were related to morphological condition, with weight, girth and blubber thickness, showing potential as non-invasive predictors of haematological status. Relationships between haematology and water temperature implied that dolphins have physiological and environmental "zones of comfort", within which condition is optimised. LDH and CPK were elevated by capture stress and post-mortem changes. Serum sodium and plasma glucose were good indicators of short-term nutritional status, but were altered by stress, which reduced their usefulness as condition indicators. BUN, albumin, globulin, albumin:globulin, total cholesterol and triglycerides appeared to be little affected by these changes and are potentially valuable indicators of condition in net-caught and/or free-ranging dolphins, particularly with respect to nutritional condition, and associated changes in morphology. Although data were limited, these parameters show the greatest potential as physiological indicators of animal condition and environmental health. The limitations of this study are recognised, however, results highlight the feasibility of using net-caught specimens to monitor the condition of free-ranging marine mammals, and the marine habitat as a whole. Relationships established in this study will be used to elucidate further on the interactive nature of marine mammal condition and aid in the development of a non-invasive condition assessment technique.
- Full Text:
Aspects of the ecology of fishes associated with salt marshes and adjacent habitats in a temperate South African estuary
- Authors: Paterson, Angus William
- Date: 1999
- Subjects: Estuarine fishes -- Ecology -- South Africa , Salt marsh ecology -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5365 , http://hdl.handle.net/10962/d1013010
- Description: There is a paucity of published information on fish utilization of salt marshes outside North America. This dissertation represents the first intensive examination of the ichthyofauna associated with salt marshes in southern Africa and examines the species composition, diversity, size structure, distribution and estuarine dependence of fishes that utilize salt marshes in the Kariega Estuary. The research was concentrated on Taylor's salt marsh, with comparative studies being conducted on other salt marshes and habitats within the marine dominated Kariega Estuary. The possible importance of salt marshes as feeding and refuge areas for fishes was examined, as was the role of salt marshes in the food web of the estuary. The fishes frequenting salt marshes in the Kariega Estuary were predominantly the juveniles of marine species, with Mugilidae being the dominant family. The ichthyofauna was distributed primarily in the intertidal creeks with very few specimens captured on the vegetated Spartina maritima and Sarcocomia perennis flats. The different reaches of the intertidal creek were characterised by distinct fish assemblages. The fish assemblages associated with the intertidal salt marsh creeks were significantly different from those found in the eelgrass beds, the other dominant intertidal habitat in the Kariega Estuary. The eelgrass beds were dominated by estuarine fish species and had a higher density and standing stock of fishes when compared to the salt marsh creeks. The diversity of fishes in the two habitats was however similar. The intertidal salt marsh creek ichthyofauna also differed significantly from that found in the main estuary channel. The creek ichthyofauna was dominated by 0+ juveniles while the main channel had many subadult and adult fishes. The channel habitat also had numerous large piscivorous fishes which were absent from the salt marsh creeks. The low number of piscivorous fishes, together with limited fish predation from other sources, may be the reason why salt marshes provide a refuge for juvenile fishes that frequent these habitats. Unlike previous studies on North American, Australian and European salt marshes, the dominant fish species that frequented Taylor's marsh were not recorded feeding extensively on the marsh, and those that did had a limited distribution. The role of fishes in the transfer of energy off the Kariega salt marshes is therefore likely to be minimal. A stable carbon isotope study on the dominant primary producers and consumers within the Kariega Estuary revealed that detritus originating from the high lying salt marsh plants Sarcocornia perennis and Chenolea diffusa was not utilized by fishes in the Kariega Estuary. Preliminary results indicated that the cord grass Spartina maritima may be an important energy source to the fishes in the Kariega Estuary, but further research is needed to confirm this.
- Full Text:
- Authors: Paterson, Angus William
- Date: 1999
- Subjects: Estuarine fishes -- Ecology -- South Africa , Salt marsh ecology -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5365 , http://hdl.handle.net/10962/d1013010
- Description: There is a paucity of published information on fish utilization of salt marshes outside North America. This dissertation represents the first intensive examination of the ichthyofauna associated with salt marshes in southern Africa and examines the species composition, diversity, size structure, distribution and estuarine dependence of fishes that utilize salt marshes in the Kariega Estuary. The research was concentrated on Taylor's salt marsh, with comparative studies being conducted on other salt marshes and habitats within the marine dominated Kariega Estuary. The possible importance of salt marshes as feeding and refuge areas for fishes was examined, as was the role of salt marshes in the food web of the estuary. The fishes frequenting salt marshes in the Kariega Estuary were predominantly the juveniles of marine species, with Mugilidae being the dominant family. The ichthyofauna was distributed primarily in the intertidal creeks with very few specimens captured on the vegetated Spartina maritima and Sarcocomia perennis flats. The different reaches of the intertidal creek were characterised by distinct fish assemblages. The fish assemblages associated with the intertidal salt marsh creeks were significantly different from those found in the eelgrass beds, the other dominant intertidal habitat in the Kariega Estuary. The eelgrass beds were dominated by estuarine fish species and had a higher density and standing stock of fishes when compared to the salt marsh creeks. The diversity of fishes in the two habitats was however similar. The intertidal salt marsh creek ichthyofauna also differed significantly from that found in the main estuary channel. The creek ichthyofauna was dominated by 0+ juveniles while the main channel had many subadult and adult fishes. The channel habitat also had numerous large piscivorous fishes which were absent from the salt marsh creeks. The low number of piscivorous fishes, together with limited fish predation from other sources, may be the reason why salt marshes provide a refuge for juvenile fishes that frequent these habitats. Unlike previous studies on North American, Australian and European salt marshes, the dominant fish species that frequented Taylor's marsh were not recorded feeding extensively on the marsh, and those that did had a limited distribution. The role of fishes in the transfer of energy off the Kariega salt marshes is therefore likely to be minimal. A stable carbon isotope study on the dominant primary producers and consumers within the Kariega Estuary revealed that detritus originating from the high lying salt marsh plants Sarcocornia perennis and Chenolea diffusa was not utilized by fishes in the Kariega Estuary. Preliminary results indicated that the cord grass Spartina maritima may be an important energy source to the fishes in the Kariega Estuary, but further research is needed to confirm this.
- Full Text:
Beyond the development impasse : the role of local economic development and community self-reliance in rural South Africa
- Authors: Binns, Tony , Nel, Etienne L
- Date: 1999
- Language: English
- Type: Article
- Identifier: vital:6673 , http://hdl.handle.net/10962/d1006647
- Description: The failure of successive generations of imported, Western development strategies and projects to deliver meaningful reductions in poverty and achieve basic needs in Africa, has provoked a deep questioning of Western concepts and methodologies of development. Non-governmental organisations and development practitioners are increasingly focusing their attention on strategies which build upon local knowledge, skills and resources. The concepts of ‘self- reliance’ and local economic development are examined in the context of development challenges which face Africa. This is followed by a detailed case study of local economic development in the rural Mpofu District of the former Ciskei Homeland, which was incorporated into the Eastern Cape province of South Africa with the demise of apartheid in 1994.
- Full Text:
- Authors: Binns, Tony , Nel, Etienne L
- Date: 1999
- Language: English
- Type: Article
- Identifier: vital:6673 , http://hdl.handle.net/10962/d1006647
- Description: The failure of successive generations of imported, Western development strategies and projects to deliver meaningful reductions in poverty and achieve basic needs in Africa, has provoked a deep questioning of Western concepts and methodologies of development. Non-governmental organisations and development practitioners are increasingly focusing their attention on strategies which build upon local knowledge, skills and resources. The concepts of ‘self- reliance’ and local economic development are examined in the context of development challenges which face Africa. This is followed by a detailed case study of local economic development in the rural Mpofu District of the former Ciskei Homeland, which was incorporated into the Eastern Cape province of South Africa with the demise of apartheid in 1994.
- Full Text:
Black South African English : where to from here?
- Authors: De Klerk, Vivian A
- Date: 1999
- Language: English
- Type: Article
- Identifier: vital:6135 , http://hdl.handle.net/10962/d1011587
- Description: Black South African English is generally regarded as the variety of English commonly used by mother-tongue speakers of South Africa's indigenous African languages in areas where English is not the language of the majority. This paper explores some of the problems involved in defining this variety, problems such as whether it is a `new' variety of English or a dialect, and problems relating to whose English it is: the English of those learners who have encountered only a smattering of English in informal contexts or the variety of English acquired during formal schooling. The second half of the paper focuses on the possible future of Black South African English (BSAE) against the backdrop of South Africa's new multilingual policy. Reasons for the continued appeal of English are examined, alongside the range of factors influencing the possible future growth of BSAE as a distinct variety. It is argued that South Africans are unlikely ever to be free not to learn English, owing to the huge economic, political and ideological constraints which make the `choice' of English inevitable. The success of current efforts to resist value judgements and recognise the worth of BSAE will depend not only on the goodwill of South Africans, and on the cooperation of all speakers of English, world-wide, but on the rate at which the variety drifts away from recognised standard forms of English.
- Full Text:
- Authors: De Klerk, Vivian A
- Date: 1999
- Language: English
- Type: Article
- Identifier: vital:6135 , http://hdl.handle.net/10962/d1011587
- Description: Black South African English is generally regarded as the variety of English commonly used by mother-tongue speakers of South Africa's indigenous African languages in areas where English is not the language of the majority. This paper explores some of the problems involved in defining this variety, problems such as whether it is a `new' variety of English or a dialect, and problems relating to whose English it is: the English of those learners who have encountered only a smattering of English in informal contexts or the variety of English acquired during formal schooling. The second half of the paper focuses on the possible future of Black South African English (BSAE) against the backdrop of South Africa's new multilingual policy. Reasons for the continued appeal of English are examined, alongside the range of factors influencing the possible future growth of BSAE as a distinct variety. It is argued that South Africans are unlikely ever to be free not to learn English, owing to the huge economic, political and ideological constraints which make the `choice' of English inevitable. The success of current efforts to resist value judgements and recognise the worth of BSAE will depend not only on the goodwill of South Africans, and on the cooperation of all speakers of English, world-wide, but on the rate at which the variety drifts away from recognised standard forms of English.
- Full Text:
Buffering strategies and bandwidth renegotiation for MPEG video streams
- Authors: Schonken, Nico
- Date: 1999
- Subjects: Video compression , Computer algorithms , Digital video
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4651 , http://hdl.handle.net/10962/d1006620 , Video compression , Computer algorithms , Digital video
- Description: This paper confirms the existence of short-term and long-term variation of the required bandwidth for MPEG videostreams. We show how the use of a small amount of buffering and GOP grouping can significantly reduce the effect of the short-term variation. By introducing a number of bandwidth renegotiation techniques, which can be applied to MPEG video streams in general, we are able to reduce the effect of long-term variation. These techniques include those that need the a priori knowledge of frame sizes as well as one that can renegotiate dynamically. A costing algorithm has also been introduced in order to compare various proposals against each other.
- Full Text:
- Authors: Schonken, Nico
- Date: 1999
- Subjects: Video compression , Computer algorithms , Digital video
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4651 , http://hdl.handle.net/10962/d1006620 , Video compression , Computer algorithms , Digital video
- Description: This paper confirms the existence of short-term and long-term variation of the required bandwidth for MPEG videostreams. We show how the use of a small amount of buffering and GOP grouping can significantly reduce the effect of the short-term variation. By introducing a number of bandwidth renegotiation techniques, which can be applied to MPEG video streams in general, we are able to reduce the effect of long-term variation. These techniques include those that need the a priori knowledge of frame sizes as well as one that can renegotiate dynamically. A costing algorithm has also been introduced in order to compare various proposals against each other.
- Full Text:
Burned, banished or burnished a pilot study of a school reintegration programme
- Authors: Horwitz, Ula Nadine
- Date: 1999
- Subjects: Learning disabled children , Burns and scalds in children , Learning disabled children -- Education -- Curricula , Learning disabled children -- Psychological aspects , Learning disabled children -- Physiological aspects
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2995 , http://hdl.handle.net/10962/d1002504 , Learning disabled children , Burns and scalds in children , Learning disabled children -- Education -- Curricula , Learning disabled children -- Psychological aspects , Learning disabled children -- Physiological aspects
- Description: It is the aim of this research to create a manual and programme for the reintegration of burn-injured primary-school learners in order to assist in their re-socialisation, and to act as a buffer against depression, conduct disorders, and academic lag. Additional aims of the programme included being resource-efficient, flexible, and compatible with Outcomes-Based Education (aBE) principles evidenced in Curriculum 2005. The final aim of the research involved designing the programme in order for teachers to be able to facilitate it. The manual and programme were evaluated through an embedded case study, encompassing a mildly disfigured burn-injured learner, his family, and his school environment by way of his class and teacher. The programme was found to be efficient in its use of resources, congruent with aBE principles, and engaging of the learners and teacher. Participation in the intervention seemed to afford the burn-injured learner with a buffer against depression, but did not prevent academic lag. Minimal teasing was encountered after the programme was implemented, which is contrary to the expected outcomes based on the literature available. Teacher facilitation was not achieved, however, numerous benefits were derived from the intervention for the majority of the participants.
- Full Text:
- Authors: Horwitz, Ula Nadine
- Date: 1999
- Subjects: Learning disabled children , Burns and scalds in children , Learning disabled children -- Education -- Curricula , Learning disabled children -- Psychological aspects , Learning disabled children -- Physiological aspects
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2995 , http://hdl.handle.net/10962/d1002504 , Learning disabled children , Burns and scalds in children , Learning disabled children -- Education -- Curricula , Learning disabled children -- Psychological aspects , Learning disabled children -- Physiological aspects
- Description: It is the aim of this research to create a manual and programme for the reintegration of burn-injured primary-school learners in order to assist in their re-socialisation, and to act as a buffer against depression, conduct disorders, and academic lag. Additional aims of the programme included being resource-efficient, flexible, and compatible with Outcomes-Based Education (aBE) principles evidenced in Curriculum 2005. The final aim of the research involved designing the programme in order for teachers to be able to facilitate it. The manual and programme were evaluated through an embedded case study, encompassing a mildly disfigured burn-injured learner, his family, and his school environment by way of his class and teacher. The programme was found to be efficient in its use of resources, congruent with aBE principles, and engaging of the learners and teacher. Participation in the intervention seemed to afford the burn-injured learner with a buffer against depression, but did not prevent academic lag. Minimal teasing was encountered after the programme was implemented, which is contrary to the expected outcomes based on the literature available. Teacher facilitation was not achieved, however, numerous benefits were derived from the intervention for the majority of the participants.
- Full Text:
Capillary membrane-immobilised polyphenol oxidase and the bioremediation of industrial phenolic effluent
- Authors: Edwards, Wade
- Date: 1999
- Subjects: Membranes (Technology) , Effluent quality , Pollutants , Phenols , Water -- Purification
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4095 , http://hdl.handle.net/10962/d1008458
- Description: Waste-generating industrialisation is intrinsically associated with population and economic proliferation. This places considerable emphasis on South Africa's water shortage due to the integral relationship between population growth rate and infrastructure development. Of the various types of industry-generated effluents, those containing organic pollutants such as phenols are generally difficult to remediate. Much work has been reported in the literature on the use of enzymes for the removal of phenols from these waste-streams but little application of this bioremediation approach has reached practical fruition. This study focuses on integrating and synergistically combining the advantages of enzyme-mediated dephenolisation of synthetic and industrial effluent with that of membrane teclmology. The ability of the enzyme polyphenol oxidase to convert phenol and a number of its derivatives to chemically reactive o-quinones has been reported extensively in the literature. These o-quinones can then physically be removed from solution using various precipitation or adsorption techniques. The enzyme is, however, plagued by a product-induced phenomenon known as suicide inactivation, which renders it inactive and thus limits its application as a bioremediation tool. Integrating membrane technology with the enzyme's catalytic ability by immobilising polyphenol oxidase onto polysulphone and poly(ether sulphone) capillary membranes enabled the physical removal of these inhibitory products from the micro-environment of the immobilised enzyme which therefore increased the phenol conversion capability of the immobilised biocatalyst. Under non-immobilised conditions it was found that when exposed to a mixture of various phenols the substrate preference of the enzyme is a function of the R-group. Under immobilised conditions, however, the substrate preference of the enzyme becomes a function of certain transport constraints imposed by the capillary membrane itself. Furthermore, by integrating a quinone-removal process in the enzyme-immobilised bioreactor configuration, a 21-fold increase in the amount of substrate converted per Unit enzyme was observed when compared to the conversion capacity of the inunobilised enzyme without the product removal step. Comparisons were also made using different membrane bioreactor configurations (orientating the capillaries transverse as opposed to parallel to the module axis) and different immobilisation matrices (poly(ether sulphone) and polysulphone capillary membranes). Conversion efficiencies as high as 77% were maintained for several hours using the combination of transverse-flow modules and novel polysulphone capillary membranes. It was therefore concluded that immobilisation of polyphenol oxidase on capillary membranes does indeed show considerable potential for future development.
- Full Text:
- Authors: Edwards, Wade
- Date: 1999
- Subjects: Membranes (Technology) , Effluent quality , Pollutants , Phenols , Water -- Purification
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4095 , http://hdl.handle.net/10962/d1008458
- Description: Waste-generating industrialisation is intrinsically associated with population and economic proliferation. This places considerable emphasis on South Africa's water shortage due to the integral relationship between population growth rate and infrastructure development. Of the various types of industry-generated effluents, those containing organic pollutants such as phenols are generally difficult to remediate. Much work has been reported in the literature on the use of enzymes for the removal of phenols from these waste-streams but little application of this bioremediation approach has reached practical fruition. This study focuses on integrating and synergistically combining the advantages of enzyme-mediated dephenolisation of synthetic and industrial effluent with that of membrane teclmology. The ability of the enzyme polyphenol oxidase to convert phenol and a number of its derivatives to chemically reactive o-quinones has been reported extensively in the literature. These o-quinones can then physically be removed from solution using various precipitation or adsorption techniques. The enzyme is, however, plagued by a product-induced phenomenon known as suicide inactivation, which renders it inactive and thus limits its application as a bioremediation tool. Integrating membrane technology with the enzyme's catalytic ability by immobilising polyphenol oxidase onto polysulphone and poly(ether sulphone) capillary membranes enabled the physical removal of these inhibitory products from the micro-environment of the immobilised enzyme which therefore increased the phenol conversion capability of the immobilised biocatalyst. Under non-immobilised conditions it was found that when exposed to a mixture of various phenols the substrate preference of the enzyme is a function of the R-group. Under immobilised conditions, however, the substrate preference of the enzyme becomes a function of certain transport constraints imposed by the capillary membrane itself. Furthermore, by integrating a quinone-removal process in the enzyme-immobilised bioreactor configuration, a 21-fold increase in the amount of substrate converted per Unit enzyme was observed when compared to the conversion capacity of the inunobilised enzyme without the product removal step. Comparisons were also made using different membrane bioreactor configurations (orientating the capillaries transverse as opposed to parallel to the module axis) and different immobilisation matrices (poly(ether sulphone) and polysulphone capillary membranes). Conversion efficiencies as high as 77% were maintained for several hours using the combination of transverse-flow modules and novel polysulphone capillary membranes. It was therefore concluded that immobilisation of polyphenol oxidase on capillary membranes does indeed show considerable potential for future development.
- Full Text:
Case studies of second language learners who excel at writing in English
- Authors: Ntete, Susan
- Date: 1999
- Subjects: Second language acquisition English language -- Study and teaching -- Foreign speakers Language and languages -- Study and teaching English language -- Writing
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1429 , http://hdl.handle.net/10962/d1003310
- Description: This study, which was carried out in Mdantsane township in the Eastern Cape, attempts to explain why some learners from the former Department of Education and Training, and whose mother-tongue is Xhosa, are more proficient English Second Language (ESL) writers than others. As one who grew up as an ESL learner, and has taught as an ESL teacher in this area, my interest in this field of study has been triggered by the concern of one who has experienced educational disadvantage. My understanding of what it means to be an ESL writer, given the status that English enjoys in South Africa presently, has been the motivating force behind this study. The study focuses on competent ESL writers. It is hoped that other researchers, teacher educators and teachers will learn something from the practices and strategies used by the learners in this study. In its investigation this study employs case studies. For purposes of triangulation, multiple sources of data collection have been used. The major areas of focus are on the learners and their ESL writing practices. Collection of data includes formal interviews with both ESL learners and their teachers, informal interviews with the learners' Xhosa teachers, observation as well as text analysis. The findings of the study suggest, among other things, that more often than not, it is learners who are motivated extroverts, ambitious go-getters and uninhibited survivors who become excellent ESL writers. Like any study, this has certain limitations. As a result the interpretation of data has been expressed in tentative terms. This does not mean that there is nothing to be gained from a study of this nature. Instead, the aim is to challenge more researchers to take up this issue, so that generalis ability across case studies can be achieved.
- Full Text:
- Authors: Ntete, Susan
- Date: 1999
- Subjects: Second language acquisition English language -- Study and teaching -- Foreign speakers Language and languages -- Study and teaching English language -- Writing
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1429 , http://hdl.handle.net/10962/d1003310
- Description: This study, which was carried out in Mdantsane township in the Eastern Cape, attempts to explain why some learners from the former Department of Education and Training, and whose mother-tongue is Xhosa, are more proficient English Second Language (ESL) writers than others. As one who grew up as an ESL learner, and has taught as an ESL teacher in this area, my interest in this field of study has been triggered by the concern of one who has experienced educational disadvantage. My understanding of what it means to be an ESL writer, given the status that English enjoys in South Africa presently, has been the motivating force behind this study. The study focuses on competent ESL writers. It is hoped that other researchers, teacher educators and teachers will learn something from the practices and strategies used by the learners in this study. In its investigation this study employs case studies. For purposes of triangulation, multiple sources of data collection have been used. The major areas of focus are on the learners and their ESL writing practices. Collection of data includes formal interviews with both ESL learners and their teachers, informal interviews with the learners' Xhosa teachers, observation as well as text analysis. The findings of the study suggest, among other things, that more often than not, it is learners who are motivated extroverts, ambitious go-getters and uninhibited survivors who become excellent ESL writers. Like any study, this has certain limitations. As a result the interpretation of data has been expressed in tentative terms. This does not mean that there is nothing to be gained from a study of this nature. Instead, the aim is to challenge more researchers to take up this issue, so that generalis ability across case studies can be achieved.
- Full Text:
Catalytic reactions of platinum group metal phthalocyanines
- Authors: Sekota, Mantoa Makoena C
- Date: 1999
- Subjects: Phthalocyanines Platinum group
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4396 , http://hdl.handle.net/10962/d1006151
- Description: The voltammetric behaviour of I-cysteine and other organic compounds such as hydrazine, hydroxylamine and methionine has been studied on GCE modified with phthalocyanine complexes of osmium, rhodium and ruthenium. For cysteine oxidation, the catalytic activity of the electrode was dependent the nature of the axial ligand. When cyanide and dimethylsulphoxide (DMSO) were used as axial ligands, giving (DMSO)(Cl)Rh(III)Pc, [(CN)₂Rh(III)Pc], (DMSO)₂0S(II)Pc and [(DMSO)₂Ru(II)Pc].2DMSO complexes, the peak current increased with repetitive scanning, indicating the increase in catalytic activity of the electrode after each scan. This behaviour was not observed when pyridine was used as axial ligand. The improvement of the catalytic activity of the GCE after the first scan has been attributed to the formation of the dimeric π-cation radical species at the electrode surface. Water soluble phthalocyanine complex ([(CN)₂Os(II)Pc]²⁻) and the tetramethyltetra-pyridinoporphyrazine complexes of Pd(II) and Pt(II), ([Pd(II)2,3Tmtppa(-2)]⁴⁺, [Pd(II)3,4Tmtppa(-2)]⁴⁺, [Pt(II)2,3Tmtppa(-2)]⁴⁺ and [Pt(II)3,4Tmtppa(-2)⁴⁺) have been prepared. [(CN)₂Os(II)Pc]²⁻ is soluble in water at pH greater 4 without the formation of dimers. The [M(II)Tmtppa(-2)]⁴⁺ (M = Pd or Pt) show high solubility in water and are stable only in acidic pHs. The cyclic voltammetry of the MPc and [M(II)Tmtppa(-2)]⁴⁺ complexes prepared, is also reported. The interactions of amino acids I-histidine and I-cysteine with the [M(II)Tmtppa(-2)]⁴⁺ complexes of Pd(II) and Pt(ll) were studied. All the [M(Il)Tmtppa(-2)]⁴⁺ are readily reduced to the monoanion species [M(Il)Tmtppa(-3)]³⁻ in the presence of histidine and cysteine. The rate constants for the interaction of [M(Il)Tmtppa(-2)]⁴⁺ complexes ofPt(II) and Pd(II), with histidine and cysteine range from approximately 2 x 10⁻³ to 0.26 dm³ mol⁻¹ s⁻¹. Kinetics of the interaction of [Co(Il)TSPc]⁴⁻ with amino acids, histidine and cysteine in pH 7.2 buffer were studied. The rate constants were found to be first order in both [Co(II)TSPc]⁴⁻ and the amino acid. The formation of [Co(III)TSPc]³⁻ in the presence of histidine occurred with the rate constant of 0.16 dm³ mol⁻¹ s⁻¹, whereas the formation of the [Co(I)TSPc]⁵⁻ species in the presence of cysteine gave the rate constant of 2.2 dm³ mo⁻¹ s¹. The relative quantum yield (QΔ) for singlet oxygen production by [(CN)₂Os(Il)Pc]²⁻, and [(CN)⁴Ru(II)Pc]²⁻ in DMF using diphenylisobenzofuran (DPBF) and a chemical quencher were determined. The quantum yield values were obtained as 0.39 ± 0.05 , and 0.76 ± 0.02 for [(CN₂Os(II)Pc]²⁻ and [(CN)₂Ru(II)Pc]²⁻ respectively. The differences in quantum yield values have been explained in terms of donor abilities of both the central metal and the axial ligands.
- Full Text:
- Authors: Sekota, Mantoa Makoena C
- Date: 1999
- Subjects: Phthalocyanines Platinum group
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4396 , http://hdl.handle.net/10962/d1006151
- Description: The voltammetric behaviour of I-cysteine and other organic compounds such as hydrazine, hydroxylamine and methionine has been studied on GCE modified with phthalocyanine complexes of osmium, rhodium and ruthenium. For cysteine oxidation, the catalytic activity of the electrode was dependent the nature of the axial ligand. When cyanide and dimethylsulphoxide (DMSO) were used as axial ligands, giving (DMSO)(Cl)Rh(III)Pc, [(CN)₂Rh(III)Pc], (DMSO)₂0S(II)Pc and [(DMSO)₂Ru(II)Pc].2DMSO complexes, the peak current increased with repetitive scanning, indicating the increase in catalytic activity of the electrode after each scan. This behaviour was not observed when pyridine was used as axial ligand. The improvement of the catalytic activity of the GCE after the first scan has been attributed to the formation of the dimeric π-cation radical species at the electrode surface. Water soluble phthalocyanine complex ([(CN)₂Os(II)Pc]²⁻) and the tetramethyltetra-pyridinoporphyrazine complexes of Pd(II) and Pt(II), ([Pd(II)2,3Tmtppa(-2)]⁴⁺, [Pd(II)3,4Tmtppa(-2)]⁴⁺, [Pt(II)2,3Tmtppa(-2)]⁴⁺ and [Pt(II)3,4Tmtppa(-2)⁴⁺) have been prepared. [(CN)₂Os(II)Pc]²⁻ is soluble in water at pH greater 4 without the formation of dimers. The [M(II)Tmtppa(-2)]⁴⁺ (M = Pd or Pt) show high solubility in water and are stable only in acidic pHs. The cyclic voltammetry of the MPc and [M(II)Tmtppa(-2)]⁴⁺ complexes prepared, is also reported. The interactions of amino acids I-histidine and I-cysteine with the [M(II)Tmtppa(-2)]⁴⁺ complexes of Pd(II) and Pt(ll) were studied. All the [M(Il)Tmtppa(-2)]⁴⁺ are readily reduced to the monoanion species [M(Il)Tmtppa(-3)]³⁻ in the presence of histidine and cysteine. The rate constants for the interaction of [M(Il)Tmtppa(-2)]⁴⁺ complexes ofPt(II) and Pd(II), with histidine and cysteine range from approximately 2 x 10⁻³ to 0.26 dm³ mol⁻¹ s⁻¹. Kinetics of the interaction of [Co(Il)TSPc]⁴⁻ with amino acids, histidine and cysteine in pH 7.2 buffer were studied. The rate constants were found to be first order in both [Co(II)TSPc]⁴⁻ and the amino acid. The formation of [Co(III)TSPc]³⁻ in the presence of histidine occurred with the rate constant of 0.16 dm³ mol⁻¹ s⁻¹, whereas the formation of the [Co(I)TSPc]⁵⁻ species in the presence of cysteine gave the rate constant of 2.2 dm³ mo⁻¹ s¹. The relative quantum yield (QΔ) for singlet oxygen production by [(CN)₂Os(Il)Pc]²⁻, and [(CN)⁴Ru(II)Pc]²⁻ in DMF using diphenylisobenzofuran (DPBF) and a chemical quencher were determined. The quantum yield values were obtained as 0.39 ± 0.05 , and 0.76 ± 0.02 for [(CN₂Os(II)Pc]²⁻ and [(CN)₂Ru(II)Pc]²⁻ respectively. The differences in quantum yield values have been explained in terms of donor abilities of both the central metal and the axial ligands.
- Full Text:
Cicadas (Hemiptera, Homoptera: Cicadoidea) of Mkomazi
- Villet, Martin H, van Noort, Simon, Packer, M
- Authors: Villet, Martin H , van Noort, Simon , Packer, M
- Date: 1999
- Subjects: To be catalogued
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/442756 , vital:74030 , ISBN , https://doi.org/10.1046/j.1472-4642.2001.00094.x
- Description: The cicadas are a group of insects belonging to the order Hemiptera which comprises a diverse range of insects including the bugs, leafhoppers, aphids, scale insects etc. The Hemiptera are characterised by specialised mouth parts that are adapted for piercing and sucking up sap from host plants or animal juices from their prey. All cicadas are plant feeders and can be extremely camouflaged when sitting and feeding on a branch, although the males give themselves away by their persistent, often high pitched calls.
- Full Text:
- Authors: Villet, Martin H , van Noort, Simon , Packer, M
- Date: 1999
- Subjects: To be catalogued
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/442756 , vital:74030 , ISBN , https://doi.org/10.1046/j.1472-4642.2001.00094.x
- Description: The cicadas are a group of insects belonging to the order Hemiptera which comprises a diverse range of insects including the bugs, leafhoppers, aphids, scale insects etc. The Hemiptera are characterised by specialised mouth parts that are adapted for piercing and sucking up sap from host plants or animal juices from their prey. All cicadas are plant feeders and can be extremely camouflaged when sitting and feeding on a branch, although the males give themselves away by their persistent, often high pitched calls.
- Full Text:
Claywork within the holographic paradigm: a transpersonal perspective on art therapy
- Authors: Diers, Belinda Gail
- Date: 1999
- Subjects: Art therapy , Transpersonal psychology , Art and holography
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2962 , http://hdl.handle.net/10962/d1002471 , Art therapy , Transpersonal psychology , Art and holography
- Description: This thesis is grounded in the theoretical discourses of art therapy and transpersonal psychology. The focus is on a single session of claywork, where a sculpture was made and discussed, leading to an understanding of some of the sculptor's central psychological issues. The overall aim of the research was to examine different hermeneutic perspectives on art therapy with clay sculpture in terms of how well they open up and do justice to the experience of the sculptor and the nature of the overall process. Within this there are two particular goals: Firstly, to examine the extent to which the holographic paradigm in comparison to other perspectives, allows a deeper access to, and deeper understanding of, transpersonal themes and processes; and secondly, to examine the extent to which processes within claywork can be understood as ritual activities. The research was a phenomenological-hermeneutic case study. The session was reduced to a narrative synopsis, and then a hermeneutically grounded thematic analysis was carried out using the theory of Transpersonal Feminism (Knight, 1997) and Schema-Focused Cognitive Therapy (young, 1990, 1994). The principal conclusions reached were that the holographic paradigm does add to our understanding of the experiences (personal and transpersonal) of the claywork, often beyond the scope of other art therapy perspectives. The image of the shaman is used as a metaphor for understanding the process of healing described within the holographic paradigm. Within the healing process, ritual plays an important role in the meaningful therapeutic activity of art therapy. The claywork expresses that the transpersonal struggle with archetypal forces within the collective unconscious is reflected on a personal level through individual conflicts and dilemmas within the personal unconscious. Indeed, these difficulties are viewed on both levels as 'stepping stones' on the path of spiritual development described by Engler (1984) and Welwood (1986).
- Full Text:
- Authors: Diers, Belinda Gail
- Date: 1999
- Subjects: Art therapy , Transpersonal psychology , Art and holography
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2962 , http://hdl.handle.net/10962/d1002471 , Art therapy , Transpersonal psychology , Art and holography
- Description: This thesis is grounded in the theoretical discourses of art therapy and transpersonal psychology. The focus is on a single session of claywork, where a sculpture was made and discussed, leading to an understanding of some of the sculptor's central psychological issues. The overall aim of the research was to examine different hermeneutic perspectives on art therapy with clay sculpture in terms of how well they open up and do justice to the experience of the sculptor and the nature of the overall process. Within this there are two particular goals: Firstly, to examine the extent to which the holographic paradigm in comparison to other perspectives, allows a deeper access to, and deeper understanding of, transpersonal themes and processes; and secondly, to examine the extent to which processes within claywork can be understood as ritual activities. The research was a phenomenological-hermeneutic case study. The session was reduced to a narrative synopsis, and then a hermeneutically grounded thematic analysis was carried out using the theory of Transpersonal Feminism (Knight, 1997) and Schema-Focused Cognitive Therapy (young, 1990, 1994). The principal conclusions reached were that the holographic paradigm does add to our understanding of the experiences (personal and transpersonal) of the claywork, often beyond the scope of other art therapy perspectives. The image of the shaman is used as a metaphor for understanding the process of healing described within the holographic paradigm. Within the healing process, ritual plays an important role in the meaningful therapeutic activity of art therapy. The claywork expresses that the transpersonal struggle with archetypal forces within the collective unconscious is reflected on a personal level through individual conflicts and dilemmas within the personal unconscious. Indeed, these difficulties are viewed on both levels as 'stepping stones' on the path of spiritual development described by Engler (1984) and Welwood (1986).
- Full Text:
Cobalt (II) porphyrazine catalysed reduction of nitrite
- Thamae, Mamothibe, Nyokong, Tebello
- Authors: Thamae, Mamothibe , Nyokong, Tebello
- Date: 1999
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/293162 , vital:57061 , xlink:href="https://doi.org/10.1016/S0022-0728(99)00224-7"
- Description: Studies on the catalytic reduction of nitrite on carbon electrodes modified with Co(II) tetra-2,3-pyridinoporphyrazine (CoTppa, 1), N,N′,N′′,N′′′-tetramethyltetra-2,3-pyridinoporphyrazine ([CoTm-2,3-tppa]4+, 2) and Co(II) N,N′,N′′,N′′′-tetramethyltetra-3,4-pyridinoporphyrazine ([CoTm-3,4-tppa]4+, 3) are reported. There is a close correspondence between the proximity of the methyl groups to the porphyrazine ring and the catalytic activity of the porphyrazine complexes. Bulk electrolysis gave ammonia and hydroxylamine as some of the products. The catalytic activity of the cationic complex, 3, towards the detection of low concentrations of nitrite (less than 10−9 M) in water containing sodium sulfate, was compared with the activities of the anionic cobalt(II) tetrasulfophthalocyanine ([CoTSPc]4−, 4) and the mixed [CoIITm-3,4-tppa]4+·[CoTSPc]4− (5) complexes. Complex 5 showed the best catalytic activity of the three in that large currents were obtained for very low concentrations of nitrite.
- Full Text:
- Authors: Thamae, Mamothibe , Nyokong, Tebello
- Date: 1999
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/293162 , vital:57061 , xlink:href="https://doi.org/10.1016/S0022-0728(99)00224-7"
- Description: Studies on the catalytic reduction of nitrite on carbon electrodes modified with Co(II) tetra-2,3-pyridinoporphyrazine (CoTppa, 1), N,N′,N′′,N′′′-tetramethyltetra-2,3-pyridinoporphyrazine ([CoTm-2,3-tppa]4+, 2) and Co(II) N,N′,N′′,N′′′-tetramethyltetra-3,4-pyridinoporphyrazine ([CoTm-3,4-tppa]4+, 3) are reported. There is a close correspondence between the proximity of the methyl groups to the porphyrazine ring and the catalytic activity of the porphyrazine complexes. Bulk electrolysis gave ammonia and hydroxylamine as some of the products. The catalytic activity of the cationic complex, 3, towards the detection of low concentrations of nitrite (less than 10−9 M) in water containing sodium sulfate, was compared with the activities of the anionic cobalt(II) tetrasulfophthalocyanine ([CoTSPc]4−, 4) and the mixed [CoIITm-3,4-tppa]4+·[CoTSPc]4− (5) complexes. Complex 5 showed the best catalytic activity of the three in that large currents were obtained for very low concentrations of nitrite.
- Full Text:
Common Property Models of Sea Tenure: A Case Study from the Roviana and Vonavona Lagoons, New Georgia, Solomon Islands
- Authors: Shankar, Aswani
- Date: 1999
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/439865 , vital:73715 , xlink:href="https://doi.org/10.1023/A:1018727607651"
- Description: In recent decades, Pacific Region indigenous sea tenure regimes have received considerable attention from social scientists who believe thatmarine-localized common entitlements and fishing practices can aid modern littoral fisheries management. The endorsement of sea tenure institutions as managerial tools, however, has proceeded without adequate consideration of their vulnerability to social and economic changes. The general view held by researchers is that Pacific Island Sea tenure regimes are generally undermined by the influence of exogenous forces resulting in an open-access commons. In this article, it is argued that the contemporary transformation of sea tenure regimes emerges not only from exogenous agency, but from a complex set of autochthonous processes. A case study from New Georgia, Solomon Islands, is presented to show how sea tenure regimes can vary within an ethnically and culturally homogeneous region. Three tenure models are presented to show how different pre- and post-European contact regional settlement patterns, localized processes of political expansion and contraction, and dynamic indigenous sociocultural principles have resulted in institutional differences between each sea tenure model. The effect of the market economy on the organizational structure and managerial outcomes of each model also is discussed.
- Full Text:
- Authors: Shankar, Aswani
- Date: 1999
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/439865 , vital:73715 , xlink:href="https://doi.org/10.1023/A:1018727607651"
- Description: In recent decades, Pacific Region indigenous sea tenure regimes have received considerable attention from social scientists who believe thatmarine-localized common entitlements and fishing practices can aid modern littoral fisheries management. The endorsement of sea tenure institutions as managerial tools, however, has proceeded without adequate consideration of their vulnerability to social and economic changes. The general view held by researchers is that Pacific Island Sea tenure regimes are generally undermined by the influence of exogenous forces resulting in an open-access commons. In this article, it is argued that the contemporary transformation of sea tenure regimes emerges not only from exogenous agency, but from a complex set of autochthonous processes. A case study from New Georgia, Solomon Islands, is presented to show how sea tenure regimes can vary within an ethnically and culturally homogeneous region. Three tenure models are presented to show how different pre- and post-European contact regional settlement patterns, localized processes of political expansion and contraction, and dynamic indigenous sociocultural principles have resulted in institutional differences between each sea tenure model. The effect of the market economy on the organizational structure and managerial outcomes of each model also is discussed.
- Full Text:
Community based natural resource management systems : an evaluation of the campfire programme in Zimbabwe : with special reference to Omay, and Makande Communal Lands in Nyaminyami District
- Authors: Sibanda, Backson M C, 1950-
- Date: 1999
- Subjects: Natural resources -- Zimbabwe -- Management
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4866 , http://hdl.handle.net/10962/d1007432
- Description: Communal Areas Management for Indigenous Resources (CAMPFIRE) is an innovative community based natural resource management strategy which transfers management and conservation responsibility from the state to the local communities. This thesis critically examines CAMPFIRE's potential for introducing sustainable natural resource management through the detailed examination of CAMPFIRE's implementation in Nyaminyami District, which is located in the Zambezi Valley of Zimbabwe. Comparisons with other districts are made as appropriate. The theoretical framework of this research is based on an examination of common property theories, theories of bundles of rights, globalisation and the notion of global commons. It is also based on critically examining Zimbabwean, African and international literature dealing with the management of natural resources used in common. There are five specific contributions which the thesis makes. Firstly, common property management is redefined and the difference between resources used in common but which are not common property and common property resources is clarified. Secondly, the study shows that CAMPFIRE is not sustainable whilst it remains dependent on wildlife alone and on a single species - the elephant. Thirdly, the thesis has attempted to extricate the CAMPFIRE concept from the wildlife debate in which it has become entangled and, fourthly, it examines the issues of globalisation and the global commons to show how decisions made at the international level impact on resource utilisation and management at the local level. Finally, the study examines what residual Tonga indigenous knowledge still exists and which aspects can be incorporated into present management systems. Overall, the results of the research suggest that while CAMPFIRE is an innovative strategy for sustainable natural resource management it, has not achieved its major objective of becoming a grassroots rural development strategy. It has become a top down elitist programme which is NGO and donor driven and government constrained. Legislation and policy need formally to address this problem. Finally, the thesis recognises the potential of the CAMPFIRE concept, especially if the weaknesses ofthe programme are addressed.
- Full Text:
- Authors: Sibanda, Backson M C, 1950-
- Date: 1999
- Subjects: Natural resources -- Zimbabwe -- Management
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4866 , http://hdl.handle.net/10962/d1007432
- Description: Communal Areas Management for Indigenous Resources (CAMPFIRE) is an innovative community based natural resource management strategy which transfers management and conservation responsibility from the state to the local communities. This thesis critically examines CAMPFIRE's potential for introducing sustainable natural resource management through the detailed examination of CAMPFIRE's implementation in Nyaminyami District, which is located in the Zambezi Valley of Zimbabwe. Comparisons with other districts are made as appropriate. The theoretical framework of this research is based on an examination of common property theories, theories of bundles of rights, globalisation and the notion of global commons. It is also based on critically examining Zimbabwean, African and international literature dealing with the management of natural resources used in common. There are five specific contributions which the thesis makes. Firstly, common property management is redefined and the difference between resources used in common but which are not common property and common property resources is clarified. Secondly, the study shows that CAMPFIRE is not sustainable whilst it remains dependent on wildlife alone and on a single species - the elephant. Thirdly, the thesis has attempted to extricate the CAMPFIRE concept from the wildlife debate in which it has become entangled and, fourthly, it examines the issues of globalisation and the global commons to show how decisions made at the international level impact on resource utilisation and management at the local level. Finally, the study examines what residual Tonga indigenous knowledge still exists and which aspects can be incorporated into present management systems. Overall, the results of the research suggest that while CAMPFIRE is an innovative strategy for sustainable natural resource management it, has not achieved its major objective of becoming a grassroots rural development strategy. It has become a top down elitist programme which is NGO and donor driven and government constrained. Legislation and policy need formally to address this problem. Finally, the thesis recognises the potential of the CAMPFIRE concept, especially if the weaknesses ofthe programme are addressed.
- Full Text:
Conservation biology and management of the Twee River redfin, Barbus erubescens (Pisces : Cyprinide)
- Authors: Marriott, Michael Stephen
- Date: 1999
- Subjects: Barbus , Cyprinidae
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5248 , http://hdl.handle.net/10962/d1005091 , Barbus , Cyprinidae
- Description: Agricultural practices and increasing levels of pollution, water abstraction and numbers of predatory exotic fishes gave rise to mounting concern for the survival of the already endangered Twee River redfin, Barbus erubescens. Numbers were believed to be dwindling and an urgent re-assessment of the species' conservation status and major threats was called for. Distribution and estimated numbers of B. erubescens were detennined from a census conducted in the Twee River catclunent, and baseline knowledge of age and growth, reproduction, diet and habitat preferences was gained from biological work on collected specimens. Such understanding was necessary to formullate management ideas. Although an estimated 40% reduction in area of occupancy has occurred in the middle reaches of the Twee River system, the known distribution of B. erubescens was extended into the upper Suurvlei River. Despite fragmentation, surviving redfin populations remained healthy and total population size was estimated at 8400 individuals, 4100 of which were considered mature. Adults preferred pools with water exceeding 1 m in depth and tended to be associated with sandy or boulder substrates. Due to low numbers no such study was conducted on juveniles, although observations indicated a preference for the upper 50 cm of the water column, in or around marginal vegetation. Barbus erubescens spawn in summer and follow an asynchronous, iteroparous pattern. Males and females reach a maximum age of six years, maturing after two years at calculated SL of 45 mm in males and 42 mm in females. The diet was dominated by simulid and ephemeropteran larvae. Although the combined pressures of pesticide and fertiliser use, predation and competition from exotic species have undoubtedly had a negative impact on B. erubescens, the species has maintained viable populations. With continued expansion of these threats the focus of conservation attention may change but, at present, it is most likely agricultural water use, amounting to 7.43 x 10⁶ m³y⁻¹, 15% of the entire catchment production, which poses the greatest immediate threat to the survival of the species. Based on a deteriorating habitat and restricted area of occupancy, B. erubescens was rated Critically Endangered, and it is recommended that a conservation management plan be implemented in the Twee River catchment. The focus of such action should be on genetic preservation, with immediate projects including gamete cryopreservation and captive breeding and rearing programmes. Catchment management, including education and rehabilitation programmes, must be the long-term aim of conservation, to ensure the survival of B. erubescens.
- Full Text:
Conservation biology and management of the Twee River redfin, Barbus erubescens (Pisces : Cyprinide)
- Authors: Marriott, Michael Stephen
- Date: 1999
- Subjects: Barbus , Cyprinidae
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5248 , http://hdl.handle.net/10962/d1005091 , Barbus , Cyprinidae
- Description: Agricultural practices and increasing levels of pollution, water abstraction and numbers of predatory exotic fishes gave rise to mounting concern for the survival of the already endangered Twee River redfin, Barbus erubescens. Numbers were believed to be dwindling and an urgent re-assessment of the species' conservation status and major threats was called for. Distribution and estimated numbers of B. erubescens were detennined from a census conducted in the Twee River catclunent, and baseline knowledge of age and growth, reproduction, diet and habitat preferences was gained from biological work on collected specimens. Such understanding was necessary to formullate management ideas. Although an estimated 40% reduction in area of occupancy has occurred in the middle reaches of the Twee River system, the known distribution of B. erubescens was extended into the upper Suurvlei River. Despite fragmentation, surviving redfin populations remained healthy and total population size was estimated at 8400 individuals, 4100 of which were considered mature. Adults preferred pools with water exceeding 1 m in depth and tended to be associated with sandy or boulder substrates. Due to low numbers no such study was conducted on juveniles, although observations indicated a preference for the upper 50 cm of the water column, in or around marginal vegetation. Barbus erubescens spawn in summer and follow an asynchronous, iteroparous pattern. Males and females reach a maximum age of six years, maturing after two years at calculated SL of 45 mm in males and 42 mm in females. The diet was dominated by simulid and ephemeropteran larvae. Although the combined pressures of pesticide and fertiliser use, predation and competition from exotic species have undoubtedly had a negative impact on B. erubescens, the species has maintained viable populations. With continued expansion of these threats the focus of conservation attention may change but, at present, it is most likely agricultural water use, amounting to 7.43 x 10⁶ m³y⁻¹, 15% of the entire catchment production, which poses the greatest immediate threat to the survival of the species. Based on a deteriorating habitat and restricted area of occupancy, B. erubescens was rated Critically Endangered, and it is recommended that a conservation management plan be implemented in the Twee River catchment. The focus of such action should be on genetic preservation, with immediate projects including gamete cryopreservation and captive breeding and rearing programmes. Catchment management, including education and rehabilitation programmes, must be the long-term aim of conservation, to ensure the survival of B. erubescens.
- Full Text:
Constitution of Food and Allied Workers Union As amended at the Bi-Annual National Conference
- Food and Allied Workers Union (FAWU)
- Authors: Food and Allied Workers Union (FAWU)
- Date: 1999
- Subjects: Food and Allied Workers Union
- Language: English
- Type: text
- Identifier: http://hdl.handle.net/10962/110099 , vital:33223
- Full Text:
- Authors: Food and Allied Workers Union (FAWU)
- Date: 1999
- Subjects: Food and Allied Workers Union
- Language: English
- Type: text
- Identifier: http://hdl.handle.net/10962/110099 , vital:33223
- Full Text:
Contents : 3 projects
- Authors: Mtongana, Lindile
- Date: 1999
- Subjects: Teachers -- In-service training School management and organization -- Parent participation Education and state -- South Africa Educational law and legislation -- South Africa
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1462 , http://hdl.handle.net/10962/d1003343
- Description: This project comprises a case study that I conducted at New Horizon High School in Butterworth, a school with a good reputation for its excellent academic standard. It is about Staff Development, which I have identified as the most vital component of effective teaching. Although there is a need to ensure that there is an adequate supply of teachers in schools, the greatest challenge lies in the development of the quality of those who are already in service. This enormous challenge seems to have been forgotten by many school leaders. I hope this study will be beneficial to school principals and teachers who want to be successful in their teaching careers in the 21st century.
- Full Text:
- Authors: Mtongana, Lindile
- Date: 1999
- Subjects: Teachers -- In-service training School management and organization -- Parent participation Education and state -- South Africa Educational law and legislation -- South Africa
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1462 , http://hdl.handle.net/10962/d1003343
- Description: This project comprises a case study that I conducted at New Horizon High School in Butterworth, a school with a good reputation for its excellent academic standard. It is about Staff Development, which I have identified as the most vital component of effective teaching. Although there is a need to ensure that there is an adequate supply of teachers in schools, the greatest challenge lies in the development of the quality of those who are already in service. This enormous challenge seems to have been forgotten by many school leaders. I hope this study will be beneficial to school principals and teachers who want to be successful in their teaching careers in the 21st century.
- Full Text: