A comparative study of conceptualisations and practices of inclusion as an aspect of social justice in three teacher education institutions in Canada, South Africa and Zimbabwe
- Authors: Musara, Ellison
- Date: 2020
- Subjects: Social justice and education , Teachers -- Training of -- Canada , Teachers -- Training of -- South Africa , Teachers -- Training of -- Zimbabwe , Educational sociology -- Canada , Educational sociology -- South Africa , Educational sociology -- Zimbabwe , Educational equalization , Inclusive education , Education -- Moral and ethical aspects , Critical realism
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/144138 , vital:38314
- Description: This study sought to examine understandings and practices of inclusion as social justice in teacher education programmes in three countries: Canada, South Africa and Zimbabwe. While inclusive education has become an issue of increasing importance globally, contemporary research shows that not much attention has been given to the preparation of teachers as a key element in developing inclusive education systems. Recognising that pre-service teacher education is vital to the success and continued development of inclusive educational practice, the purpose of this qualitative study was to better understand the ways in which inclusion is understood and practiced in the field of teacher education. Using Roy Bhaskar’s (1978) critical realism as a metatheory and drawing on Fraser’s substantive theory of social justice (2008, 2009) and Tronto’s ethic of care (1993, 2013), this study explored the extent to which teacher education faculty and teacher candidates understood and practiced inclusion as an aspect of social justice. The data used in this study was generated through individual and focus group interviews and document analysis in three higher education institutions, one in each of the three countries. In Canada, four teacher educators took part in the interviews while five teacher candidates participated in the focus group. Similarly, in South Africa, three teacher educators and eight teacher candidates participated, and in Zimbabwe, four teacher educators and eight teacher candidates took part in the study respectively. Findings from the study revealed that inclusion still means different things to different people, reflecting contrasting theoretical and ideological orientations from which inclusion is considered, while still remaining a major educational policy concern in all three countries. In the Canadian and South African institutions, inclusion is viewed more in terms of systemic educational change in pursuit of equity, social justice and equal educational opportunities for all learners. In the Zimbabwean institution, the primary focus of inclusion remains creating conditions that make it possible for students with disabilities to overcome barriers to learning and participation by providing specialist educational measures and interventions intended to respond to specific forms of impairment. As a comparative study, it is hoped that this study will contribute to the knowledge of variations and patterns in the ways in which inclusive education is shaped by societal forces such as political, economic and cultural conditions.
- Full Text:
- Date Issued: 2020
- Authors: Musara, Ellison
- Date: 2020
- Subjects: Social justice and education , Teachers -- Training of -- Canada , Teachers -- Training of -- South Africa , Teachers -- Training of -- Zimbabwe , Educational sociology -- Canada , Educational sociology -- South Africa , Educational sociology -- Zimbabwe , Educational equalization , Inclusive education , Education -- Moral and ethical aspects , Critical realism
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/144138 , vital:38314
- Description: This study sought to examine understandings and practices of inclusion as social justice in teacher education programmes in three countries: Canada, South Africa and Zimbabwe. While inclusive education has become an issue of increasing importance globally, contemporary research shows that not much attention has been given to the preparation of teachers as a key element in developing inclusive education systems. Recognising that pre-service teacher education is vital to the success and continued development of inclusive educational practice, the purpose of this qualitative study was to better understand the ways in which inclusion is understood and practiced in the field of teacher education. Using Roy Bhaskar’s (1978) critical realism as a metatheory and drawing on Fraser’s substantive theory of social justice (2008, 2009) and Tronto’s ethic of care (1993, 2013), this study explored the extent to which teacher education faculty and teacher candidates understood and practiced inclusion as an aspect of social justice. The data used in this study was generated through individual and focus group interviews and document analysis in three higher education institutions, one in each of the three countries. In Canada, four teacher educators took part in the interviews while five teacher candidates participated in the focus group. Similarly, in South Africa, three teacher educators and eight teacher candidates participated, and in Zimbabwe, four teacher educators and eight teacher candidates took part in the study respectively. Findings from the study revealed that inclusion still means different things to different people, reflecting contrasting theoretical and ideological orientations from which inclusion is considered, while still remaining a major educational policy concern in all three countries. In the Canadian and South African institutions, inclusion is viewed more in terms of systemic educational change in pursuit of equity, social justice and equal educational opportunities for all learners. In the Zimbabwean institution, the primary focus of inclusion remains creating conditions that make it possible for students with disabilities to overcome barriers to learning and participation by providing specialist educational measures and interventions intended to respond to specific forms of impairment. As a comparative study, it is hoped that this study will contribute to the knowledge of variations and patterns in the ways in which inclusive education is shaped by societal forces such as political, economic and cultural conditions.
- Full Text:
- Date Issued: 2020
A comparative study of egg development in two species of Siphonariid limpets with contrasting developmental modes
- Authors: Pal, Purba
- Date: 2004
- Subjects: Siphonariidae -- Eggs Siphonariidae -- Spawning Limpets
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5826 , http://hdl.handle.net/10962/d1007663
- Description: The family Siphonariidae is considered primitive amongst the basommatophorans although the ancestry and evolutionary relationships of these marine pulmonates are far from settled. This thesis investigates and compares different aspects of egg development and the female reproductive system in two sympatric species of Siphonaria with different developmental mode (S. capensis, a planktonic developer and S. serrata, a direct developer). The study on the seasonality of gametogenesis and spawning shows that they are both spring/summer spawners with continuous sperm production. The egg production is highest in spring and summer with a brief interruption in winter months. The gametogenic cycle when examinated, reveals that both species are simultaneous hermaphrodites once sexually mature. Amongst various factors that are investigated, density of animals has a positive effect on the number of spawn only during peak spawning. Larger individuals of S. capensis and S. serrata contains more mature oocytes in the gonad indicating that the shell length and fecundity of these two limpets are positively correlated. By contrast, parasitism by trematodes has a drastic effect on the reproductive output of these limpets leaving them completely castrated. Egg development in S. capensis and S. serrata shows that both produce yolk auto synthetically (with the help of organelles like RER, Golgi bodies) but S. serrata also incorporates some high molecular weight precursors via endocytotis. The structure as well as the biochemical composition of the egg ribbons is also different between these two species with higher carbohydrate and protein content of collar shaped spawn of S. serrata. S. capensis produces egg ribbons of less fibrous nature containing thinner egg capsules compared to the direct developer. A comparison of both the glandular complex and spermatheca between these two limpets shows no inter specific difference in the structure although the glandular complex of the siphonariids shows fine structural and histochemical similarities with the albumen gland and membrane gland of the opisthobranchs. The structure of the spermatheca suggests that in both species the organ most possibly receives sperm (for degradation only?) and may transport them via the spermathecal duct (for fertilization?). Finally, it is suggested that S. capensis and S. serrata exhibit primitive features (e.g., an autosynthetic mode of vitellogenesis in S. capensis and a single glandular complex composed of an albumen and a mucous gland) compared to other basommatophorans, which should be considered in future phylogenetic investigations.
- Full Text:
- Date Issued: 2004
- Authors: Pal, Purba
- Date: 2004
- Subjects: Siphonariidae -- Eggs Siphonariidae -- Spawning Limpets
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5826 , http://hdl.handle.net/10962/d1007663
- Description: The family Siphonariidae is considered primitive amongst the basommatophorans although the ancestry and evolutionary relationships of these marine pulmonates are far from settled. This thesis investigates and compares different aspects of egg development and the female reproductive system in two sympatric species of Siphonaria with different developmental mode (S. capensis, a planktonic developer and S. serrata, a direct developer). The study on the seasonality of gametogenesis and spawning shows that they are both spring/summer spawners with continuous sperm production. The egg production is highest in spring and summer with a brief interruption in winter months. The gametogenic cycle when examinated, reveals that both species are simultaneous hermaphrodites once sexually mature. Amongst various factors that are investigated, density of animals has a positive effect on the number of spawn only during peak spawning. Larger individuals of S. capensis and S. serrata contains more mature oocytes in the gonad indicating that the shell length and fecundity of these two limpets are positively correlated. By contrast, parasitism by trematodes has a drastic effect on the reproductive output of these limpets leaving them completely castrated. Egg development in S. capensis and S. serrata shows that both produce yolk auto synthetically (with the help of organelles like RER, Golgi bodies) but S. serrata also incorporates some high molecular weight precursors via endocytotis. The structure as well as the biochemical composition of the egg ribbons is also different between these two species with higher carbohydrate and protein content of collar shaped spawn of S. serrata. S. capensis produces egg ribbons of less fibrous nature containing thinner egg capsules compared to the direct developer. A comparison of both the glandular complex and spermatheca between these two limpets shows no inter specific difference in the structure although the glandular complex of the siphonariids shows fine structural and histochemical similarities with the albumen gland and membrane gland of the opisthobranchs. The structure of the spermatheca suggests that in both species the organ most possibly receives sperm (for degradation only?) and may transport them via the spermathecal duct (for fertilization?). Finally, it is suggested that S. capensis and S. serrata exhibit primitive features (e.g., an autosynthetic mode of vitellogenesis in S. capensis and a single glandular complex composed of an albumen and a mucous gland) compared to other basommatophorans, which should be considered in future phylogenetic investigations.
- Full Text:
- Date Issued: 2004
A comparative study of the catechin components in the barks of wattle species related to Acacia Mernsii
- Authors: Maihs, Edwin Alfred
- Date: 1962
- Subjects: Wattles (Plants) Acacia mearnsii Acacia
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4482 , http://hdl.handle.net/10962/d1012793
- Description: The distribution of flavonoid constituents in the barks of Acacia mearnsii De Wild.(black wattle) , A· decurens Willd. (green wattle), A. dealbata Link.(silver wattle) and A. pycnantha Benth.(golden wattle) has been studied. Bark extracts of the four wattle species have been fractionated into low molecular weight fractions containing mainly catechins and other low molecular weight constituents, and high molecular weight fractions containing the bulk of the polymerized tannins. The low molecular weight fractions have been further fractionated by "preparative paper chromatography". (-)-Robinetinidol, (-)-7:3': 4': 5'-tetrahydroxy flavan- 3-ol, a new naturally occurring catechin, (+)-catechin and (+)-gallocatechin have been isolated from the barks of A. mearnsii, A. dealbata and A. pycnantha. (-)-Epicatechin and (-)-epigallocatechin have been identified in the bark extracts of A. dealbata and A. pycnantha, but appeared to be absent in the barks of A. mearnsii and A. decurrens. (-)-Epicatechin has been isolated fron A. dealbata, and both (-}-epicatechin and (-)-epigallocatechin were isolated from A. pycnantha. (-)-Epicatechin gallate, (-)-epigallocatechin gallate and gallic acid were isolated from A. pycnantha only. These three constituents appeared to be absent in the barks of the three other wattle species. (-)-Epigallocatechin, (-)-epicatechin gallate and (-)-epigallocatechin gallate which were not available for direct comparison, were subsequently isolated from green tea where they are present as major phenolic constituents. A method for the quantitative estimation of polyphenolic substances on two dimensional paper chromatograms has been developed, and a photoelectric densitometer constructed. Two spray reagents, ammoniacal silver nitrate and bisdiazotised benzidine, were found to give straight line relationships of instrument deflection against log concentration for flavonoid substances. This estimation method for the first time supplied means for a detailed study of the concentration of catechin constituents in the bark extracts of A. mearnsii, A. decurrens, A. dealbata, A. pycnantha and of A. mearnsii x A. decurrens hybrids. The concentration of catechin constituents has been shown to vary considerably between species whereas variation within species was small. In the latter respect silver wattle is an exception. Taxonomic significance may possibly be attached to the distribution of catechin constituents in the bark of the four Acacia species. The concentration of (-)-robinetinidol, which appears to be the characteristic compound of these Acacias, progressively decreases in the sequence black-, black x green hybrid, green-, silver- and golden wattle, while the number of catechin constituents of the "phloroglucinol series" increases in the same sequence. It thus appears, that by the examination of their bark components, a differentiation between species of a subgenera may be possible. Two tannins, constituents D and B, which are related to the leuco-anthocyanidins (flavan-3:4-diols) have been found in the barks of the four wattle species. One of the two, constituent D, was isolated in a pure form from the barks of A. mearnsii and A. pycnantha. Constituent D was found to generate robinetinidin and an orange pigment, the structure of which has not yet been fully identified. Compound D and its acetyl- and methoxyl derivatives did not crystallize. From the results of alkaline-, acidic- and enzymatic degradations, colour reactions and light-absorption studies, combustion analysis of the compound and its derivatives and molecular weight estimations, constituent D is surmised to be a dimer of 7:3': 4': 5'-tetrahydroxyflavan-3:4-diol (leuco-robinetinidin), The isolation of this complex leuco-anthocyanidin tannin represents the first isolation of a flavonoid tannin from commercial vegetable tannin sources. The second tannin obtained from the bark of A.mearnsii, "constituent B" appears to consist of two overlapping substances, which have not yet been separated. The tannin (B) was found to have an average molecular weight of 676 and it is considered likely that both substances may be dimolecular. On heating with mineral acid robinetinidin, fisetinidin and an orange pigment are generated, the pigment being identical with the pigment generated from constituent D. It may therefore be assumed that "Constituent B" consists of a mixture of complex leuco-robinetinidins and leucofisetinidins. The distribution of complex leuco-anthocyanidins in the bark extracts of Acacia mearnsii, A. decurrens, A. dealbata and A. pycnantha has been examined. A correlation between the distribution of leuco-anthocyanidins in the bark of the four wattle species, and accepted systematics, does not, apparently, exist.
- Full Text:
- Date Issued: 1962
- Authors: Maihs, Edwin Alfred
- Date: 1962
- Subjects: Wattles (Plants) Acacia mearnsii Acacia
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4482 , http://hdl.handle.net/10962/d1012793
- Description: The distribution of flavonoid constituents in the barks of Acacia mearnsii De Wild.(black wattle) , A· decurens Willd. (green wattle), A. dealbata Link.(silver wattle) and A. pycnantha Benth.(golden wattle) has been studied. Bark extracts of the four wattle species have been fractionated into low molecular weight fractions containing mainly catechins and other low molecular weight constituents, and high molecular weight fractions containing the bulk of the polymerized tannins. The low molecular weight fractions have been further fractionated by "preparative paper chromatography". (-)-Robinetinidol, (-)-7:3': 4': 5'-tetrahydroxy flavan- 3-ol, a new naturally occurring catechin, (+)-catechin and (+)-gallocatechin have been isolated from the barks of A. mearnsii, A. dealbata and A. pycnantha. (-)-Epicatechin and (-)-epigallocatechin have been identified in the bark extracts of A. dealbata and A. pycnantha, but appeared to be absent in the barks of A. mearnsii and A. decurrens. (-)-Epicatechin has been isolated fron A. dealbata, and both (-}-epicatechin and (-)-epigallocatechin were isolated from A. pycnantha. (-)-Epicatechin gallate, (-)-epigallocatechin gallate and gallic acid were isolated from A. pycnantha only. These three constituents appeared to be absent in the barks of the three other wattle species. (-)-Epigallocatechin, (-)-epicatechin gallate and (-)-epigallocatechin gallate which were not available for direct comparison, were subsequently isolated from green tea where they are present as major phenolic constituents. A method for the quantitative estimation of polyphenolic substances on two dimensional paper chromatograms has been developed, and a photoelectric densitometer constructed. Two spray reagents, ammoniacal silver nitrate and bisdiazotised benzidine, were found to give straight line relationships of instrument deflection against log concentration for flavonoid substances. This estimation method for the first time supplied means for a detailed study of the concentration of catechin constituents in the bark extracts of A. mearnsii, A. decurrens, A. dealbata, A. pycnantha and of A. mearnsii x A. decurrens hybrids. The concentration of catechin constituents has been shown to vary considerably between species whereas variation within species was small. In the latter respect silver wattle is an exception. Taxonomic significance may possibly be attached to the distribution of catechin constituents in the bark of the four Acacia species. The concentration of (-)-robinetinidol, which appears to be the characteristic compound of these Acacias, progressively decreases in the sequence black-, black x green hybrid, green-, silver- and golden wattle, while the number of catechin constituents of the "phloroglucinol series" increases in the same sequence. It thus appears, that by the examination of their bark components, a differentiation between species of a subgenera may be possible. Two tannins, constituents D and B, which are related to the leuco-anthocyanidins (flavan-3:4-diols) have been found in the barks of the four wattle species. One of the two, constituent D, was isolated in a pure form from the barks of A. mearnsii and A. pycnantha. Constituent D was found to generate robinetinidin and an orange pigment, the structure of which has not yet been fully identified. Compound D and its acetyl- and methoxyl derivatives did not crystallize. From the results of alkaline-, acidic- and enzymatic degradations, colour reactions and light-absorption studies, combustion analysis of the compound and its derivatives and molecular weight estimations, constituent D is surmised to be a dimer of 7:3': 4': 5'-tetrahydroxyflavan-3:4-diol (leuco-robinetinidin), The isolation of this complex leuco-anthocyanidin tannin represents the first isolation of a flavonoid tannin from commercial vegetable tannin sources. The second tannin obtained from the bark of A.mearnsii, "constituent B" appears to consist of two overlapping substances, which have not yet been separated. The tannin (B) was found to have an average molecular weight of 676 and it is considered likely that both substances may be dimolecular. On heating with mineral acid robinetinidin, fisetinidin and an orange pigment are generated, the pigment being identical with the pigment generated from constituent D. It may therefore be assumed that "Constituent B" consists of a mixture of complex leuco-robinetinidins and leucofisetinidins. The distribution of complex leuco-anthocyanidins in the bark extracts of Acacia mearnsii, A. decurrens, A. dealbata and A. pycnantha has been examined. A correlation between the distribution of leuco-anthocyanidins in the bark of the four wattle species, and accepted systematics, does not, apparently, exist.
- Full Text:
- Date Issued: 1962
A comparative study of the Grey-headed Sparrow (Passer griseus L) and the House Sparrow (Passer domesticus L) in Malawi
- Authors: Nhlane, Martin Edwin Darwin
- Date: 1997
- Subjects: English sparrow Sparrows
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5654 , http://hdl.handle.net/10962/d1005337
- Description: The House Sparrow Passer domesticus, an introduced species, and the Grey-headed Sparrow Passer griseus, an indigenous species, are sympatric in Malawi. Their distribution in the country and any possible interactions were studied, principally in southern Malawi. A morphological analysis of museum specimens confirmed that grey-headed sparrows in Malawi belong to the Northern Grey-headed Sparrow Passer griseus as distinct from the Southern Grey-headed Sparrow Passer diffusus. This species was widely distributed in the, country in association with human dwellings, both in rural areas as well as urban centres. In the northern region Greyheaded Sparrows were more abundant in the urban centres than rural areas, but in the central and southern regions numbers in the rural and urban areas were more or less the same. In Blantyre City, where they are in sympatry with the House Sparrow, they were found in the low density and industrial areas and were absent from the high density areas. The House Sparrow, arrived in Malawi in 1967 at Chileka in the southern region. Since then it has spread northwards, moving from the southern to the central and northern regions. House Sparrow numbers were found to be progressively larger in the southern region and lowest in the northern region. House Sparrows were found at sites where food was readily available, as in the immediate vicinity of houses. In the central and northern regions they were restricted mainly to urban areas. In the southern region, they occur both in rural and urban areas, probably as a reflection of the larger period of colonization in the south. In the northern region their movement has apparently been restricted by geographical barriers. In Blantyre City Grey-headed Sparrows preferred areas where tree density was high and house density was low, while House Sparrows preferred areas where house density was high and tree density was low. There was a positive correlation between Greyheaded Sparrow numbers and tree density and a negative correlation with house density. House Sparrow abundance was negatively correlated with tree density and positively correlated with house density. Grey-headed Sparrows bred in the rainy season, whereas House Sparrows bred throughout the year. There were differences in nest site selection: Grey-headed Sparrows used artificial structures such as fencing poles, and wooden telephone or electricity poles. The House Sparrow used mostly buildings and nested in crevices, holes in walls and between the walls and rafters. Nest height also differed- Grey-headed Sparrows nested at heights ranging from 1 - 8 m while House Sparrow nests were at heights of 1 - 5 m. Moult data suggests that although the House Sparrows breed throughout the year, they moult at a particular time of the year when breeding is less common. Grey-headed Sparrows were found to moult mainly from May to September in southern Africa and from June to September in central Africa. In both cases the breeding season extends over a similar period from about October to April/May of the following year. Peak moult periods differed between the House Sparrows and Grey-headed Sparrows. House Sparrows moulted mainly in the first half of the year, and Greyheaded Sparrows in the second six months. The clutch sizes of the two species were similar (mean 3.9 eggs for the House Sparrow and 3.4 for the Grey-headed Sparrow). The clutch size of the House Sparrow varied seasonally and was larger from November to May. The average incubation period for the House Sparrow was 11.5 days and the fledging period 15.4 days. The Grey-headed Sparrow fledging period was 14.7 days. Chick mortality of the House Sparrow at Chikunda farm was attributed to starvation resulting from brood reduction, abandonment, predation, low birth weight, accidental deaths and parasitism by fly larvae. Both Grey-headed and House Sparrows fed their young on insect food. Male House Sparrows fed actively initially, but their contribution declined from about day five onwards. In the Grey-headed Sparrow, both parents fed their young equally throughout the nestling period. House Sparrows fed on the ground near houses; Grey-headed Sparrows fed both on the ground away from houses and in tree canopies. The Grey-headed Sparrow walked as it fed on the ground as opposed to the House sparrow which hopped. Grey-headed Sparrows fed mainly as pairs and singletons while House Sparrows fed as family groups. Larger feeding groups of Grey-headed Sparrows were seen in the northern region at areas where food was plentiful. Where the two sparrows were seen feeding together, there was no direct competition for food. Where individual distance was violated; male House Sparrows displaced Grey-headed Sparrows which landed too close to them. Overall it appears that the distribution of the two species is determined more by their responses to habitat conditions than by interspecific interactions.
- Full Text:
- Date Issued: 1997
- Authors: Nhlane, Martin Edwin Darwin
- Date: 1997
- Subjects: English sparrow Sparrows
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5654 , http://hdl.handle.net/10962/d1005337
- Description: The House Sparrow Passer domesticus, an introduced species, and the Grey-headed Sparrow Passer griseus, an indigenous species, are sympatric in Malawi. Their distribution in the country and any possible interactions were studied, principally in southern Malawi. A morphological analysis of museum specimens confirmed that grey-headed sparrows in Malawi belong to the Northern Grey-headed Sparrow Passer griseus as distinct from the Southern Grey-headed Sparrow Passer diffusus. This species was widely distributed in the, country in association with human dwellings, both in rural areas as well as urban centres. In the northern region Greyheaded Sparrows were more abundant in the urban centres than rural areas, but in the central and southern regions numbers in the rural and urban areas were more or less the same. In Blantyre City, where they are in sympatry with the House Sparrow, they were found in the low density and industrial areas and were absent from the high density areas. The House Sparrow, arrived in Malawi in 1967 at Chileka in the southern region. Since then it has spread northwards, moving from the southern to the central and northern regions. House Sparrow numbers were found to be progressively larger in the southern region and lowest in the northern region. House Sparrows were found at sites where food was readily available, as in the immediate vicinity of houses. In the central and northern regions they were restricted mainly to urban areas. In the southern region, they occur both in rural and urban areas, probably as a reflection of the larger period of colonization in the south. In the northern region their movement has apparently been restricted by geographical barriers. In Blantyre City Grey-headed Sparrows preferred areas where tree density was high and house density was low, while House Sparrows preferred areas where house density was high and tree density was low. There was a positive correlation between Greyheaded Sparrow numbers and tree density and a negative correlation with house density. House Sparrow abundance was negatively correlated with tree density and positively correlated with house density. Grey-headed Sparrows bred in the rainy season, whereas House Sparrows bred throughout the year. There were differences in nest site selection: Grey-headed Sparrows used artificial structures such as fencing poles, and wooden telephone or electricity poles. The House Sparrow used mostly buildings and nested in crevices, holes in walls and between the walls and rafters. Nest height also differed- Grey-headed Sparrows nested at heights ranging from 1 - 8 m while House Sparrow nests were at heights of 1 - 5 m. Moult data suggests that although the House Sparrows breed throughout the year, they moult at a particular time of the year when breeding is less common. Grey-headed Sparrows were found to moult mainly from May to September in southern Africa and from June to September in central Africa. In both cases the breeding season extends over a similar period from about October to April/May of the following year. Peak moult periods differed between the House Sparrows and Grey-headed Sparrows. House Sparrows moulted mainly in the first half of the year, and Greyheaded Sparrows in the second six months. The clutch sizes of the two species were similar (mean 3.9 eggs for the House Sparrow and 3.4 for the Grey-headed Sparrow). The clutch size of the House Sparrow varied seasonally and was larger from November to May. The average incubation period for the House Sparrow was 11.5 days and the fledging period 15.4 days. The Grey-headed Sparrow fledging period was 14.7 days. Chick mortality of the House Sparrow at Chikunda farm was attributed to starvation resulting from brood reduction, abandonment, predation, low birth weight, accidental deaths and parasitism by fly larvae. Both Grey-headed and House Sparrows fed their young on insect food. Male House Sparrows fed actively initially, but their contribution declined from about day five onwards. In the Grey-headed Sparrow, both parents fed their young equally throughout the nestling period. House Sparrows fed on the ground near houses; Grey-headed Sparrows fed both on the ground away from houses and in tree canopies. The Grey-headed Sparrow walked as it fed on the ground as opposed to the House sparrow which hopped. Grey-headed Sparrows fed mainly as pairs and singletons while House Sparrows fed as family groups. Larger feeding groups of Grey-headed Sparrows were seen in the northern region at areas where food was plentiful. Where the two sparrows were seen feeding together, there was no direct competition for food. Where individual distance was violated; male House Sparrows displaced Grey-headed Sparrows which landed too close to them. Overall it appears that the distribution of the two species is determined more by their responses to habitat conditions than by interspecific interactions.
- Full Text:
- Date Issued: 1997
A comparative study of the in vitro antidiabetic properties, cytotoxicity and mechanism of action of Albuca bracteata and Albuca setosa bulb extracts
- Authors: Odeyemi, Samuel Wale
- Date: 2015
- Subjects: Medicinal plants Herbs -- Therapeutic use Diabetics -- Alternative treatment
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/3154 , vital:28327
- Description: The search for cheap, non toxic and readily available antidiabetic drugs has been a challenge for researchers and the pharmaceutical industries. Diabetes mellitus is a metabolic disease characterized by defects in the synthesis of insulin and/or insensitivity to the action of insulin at the target cells. The disease has been on the increase mostly in developing countries where large proportions of the population have little access to good medical care due to either accessibility or non availability of synthetic drugs. This has led to the use of medicinal plants to treat diabetes because it is safe, cheap and with few side effects. There is little scientific evidence on the dosages, active compounds, mechanisms of action and toxicity of these traditionally used plants. Two of the most frequently used plants; Albuca setosa and Albuca bracteata were investigated in this study. The qualitative analysis of different extractions of these plants revealed the presence of phenolics, alkaloids, tannins and saponins. The antioxidant properties of aqueous, acetone and methanollic extracts of Albuca setosa and Albuca bracteata were investigated using models such as Diphenyl-1-Picrylhydrazyl (DPPH), 2, 2’-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) (ABTS), Ferric ion reducing antioxidant potential (FRAP), Nitric Oxide and Hydrogen Peroxide (H2O2). Both plants revealed inhibitions against DPPH in a concentration - dependent manner with Albuca setosa (0.330 mg/ml) showing higher activity than Albuca bracteata (0.647 mg/ml) determined from the IC50. The aqueous extract of Albuca setosa showed a higher inhibition against DPPH radical compared to the Albuca bracteata aqueous extract at all concentrations investigated. The isolated saponins from Albuca bracteata had a higher DPPH scavenging activity than the crude methanolic extract of the plant in a concentration - dependent manner but are significantly different from each other at 0.4, 0.6 and 1.0 mg/ml only. The IC50 of the saponins was also observed to be higher than the crude extracts and standards.The Albuca setosa aqueous extract showed a higher percentage inhibition of ABTS radicals than Albuca bracteata at all the concentrations investigated. Overall, the Albuca setosa aqueous extract (0.0809 mg/ml) showed maximum activity against ABTS radicals. The iron reducing power was significantly higher (P < 0.05) in the methanolic extract of both plants compared to the aqueous counterpart. Overall, the Albuca bracteata aqueous extract (0.344 mg/ml) showed maximum activity as indicated by the IC50. The aqueous extracts of both plants also revealed percentage inhibitions in a concentration - dependent manner against NO2. The aqueous extract of Albuca bracteata bulb was more active against nitric oxide and hydrogen peroxide inhibition. In this study, the cytotoxicity of the extracts was evaluated at a high dose of 100 μg/ml on Chang liver cells and determined using MTT, crystal violet, glucose consumption, lactate production and lactate dehydrogenase release and FRAP. The aqueous extracts of both Albuca setosa and Albuca bracteata were non-toxic on Chang liver cells at the concentrations investigated. The MTT revealed that the aqueous extract of Albuca setosa bulb had the optimum cell viability of 108.09 percent while the acetonic extract of Albuca bracteata showed the least cell viability (37.72 percent) compared with the control. The crystal violet test also revealed the acetone extract of Albuca bracteata to have the least percentage of cell viability at 31.47 percent, while the aqueous extract of Albuca setosa showed the maximum cell viability at 112.5 percent. The aqueous extracts of both plants showed higher percentage cell density on the second day of incubation from the proliferation assay. All the tested samples were observed to consume more glucose than the blank except for the methanollic and acetone extracts of Albuca bracteata bulb. The aqueous and methanolic extracts of Albuca setosa bulbs produced the highest lactate with 120.2 μg/ml and 113.7 μg/ml respectively. The acetone extracts of both Albuca setosa and Albuca bracteata revealed toxicity with a higher lactate dehydrogenase release compared to the control.
- Full Text:
- Date Issued: 2015
- Authors: Odeyemi, Samuel Wale
- Date: 2015
- Subjects: Medicinal plants Herbs -- Therapeutic use Diabetics -- Alternative treatment
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/3154 , vital:28327
- Description: The search for cheap, non toxic and readily available antidiabetic drugs has been a challenge for researchers and the pharmaceutical industries. Diabetes mellitus is a metabolic disease characterized by defects in the synthesis of insulin and/or insensitivity to the action of insulin at the target cells. The disease has been on the increase mostly in developing countries where large proportions of the population have little access to good medical care due to either accessibility or non availability of synthetic drugs. This has led to the use of medicinal plants to treat diabetes because it is safe, cheap and with few side effects. There is little scientific evidence on the dosages, active compounds, mechanisms of action and toxicity of these traditionally used plants. Two of the most frequently used plants; Albuca setosa and Albuca bracteata were investigated in this study. The qualitative analysis of different extractions of these plants revealed the presence of phenolics, alkaloids, tannins and saponins. The antioxidant properties of aqueous, acetone and methanollic extracts of Albuca setosa and Albuca bracteata were investigated using models such as Diphenyl-1-Picrylhydrazyl (DPPH), 2, 2’-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) (ABTS), Ferric ion reducing antioxidant potential (FRAP), Nitric Oxide and Hydrogen Peroxide (H2O2). Both plants revealed inhibitions against DPPH in a concentration - dependent manner with Albuca setosa (0.330 mg/ml) showing higher activity than Albuca bracteata (0.647 mg/ml) determined from the IC50. The aqueous extract of Albuca setosa showed a higher inhibition against DPPH radical compared to the Albuca bracteata aqueous extract at all concentrations investigated. The isolated saponins from Albuca bracteata had a higher DPPH scavenging activity than the crude methanolic extract of the plant in a concentration - dependent manner but are significantly different from each other at 0.4, 0.6 and 1.0 mg/ml only. The IC50 of the saponins was also observed to be higher than the crude extracts and standards.The Albuca setosa aqueous extract showed a higher percentage inhibition of ABTS radicals than Albuca bracteata at all the concentrations investigated. Overall, the Albuca setosa aqueous extract (0.0809 mg/ml) showed maximum activity against ABTS radicals. The iron reducing power was significantly higher (P < 0.05) in the methanolic extract of both plants compared to the aqueous counterpart. Overall, the Albuca bracteata aqueous extract (0.344 mg/ml) showed maximum activity as indicated by the IC50. The aqueous extracts of both plants also revealed percentage inhibitions in a concentration - dependent manner against NO2. The aqueous extract of Albuca bracteata bulb was more active against nitric oxide and hydrogen peroxide inhibition. In this study, the cytotoxicity of the extracts was evaluated at a high dose of 100 μg/ml on Chang liver cells and determined using MTT, crystal violet, glucose consumption, lactate production and lactate dehydrogenase release and FRAP. The aqueous extracts of both Albuca setosa and Albuca bracteata were non-toxic on Chang liver cells at the concentrations investigated. The MTT revealed that the aqueous extract of Albuca setosa bulb had the optimum cell viability of 108.09 percent while the acetonic extract of Albuca bracteata showed the least cell viability (37.72 percent) compared with the control. The crystal violet test also revealed the acetone extract of Albuca bracteata to have the least percentage of cell viability at 31.47 percent, while the aqueous extract of Albuca setosa showed the maximum cell viability at 112.5 percent. The aqueous extracts of both plants showed higher percentage cell density on the second day of incubation from the proliferation assay. All the tested samples were observed to consume more glucose than the blank except for the methanollic and acetone extracts of Albuca bracteata bulb. The aqueous and methanolic extracts of Albuca setosa bulbs produced the highest lactate with 120.2 μg/ml and 113.7 μg/ml respectively. The acetone extracts of both Albuca setosa and Albuca bracteata revealed toxicity with a higher lactate dehydrogenase release compared to the control.
- Full Text:
- Date Issued: 2015
A comparative study of the language, mathematics and science literacy knowledge and skills of grade 9 learners in secondary schools in Port Elizabeth
- Authors: Arnolds, Keith Victor
- Date: 2012
- Subjects: Educational tests and measurements -- South Africa -- Port Elizabeth , Comparative education , Language and languages -- Study and teaching -- South Africa -- Port Elizabeth , Mathematics -- Study and teaching -- South Africa -- Port Elizabeth , Science -- Study and teaching -- South Africa -- Port Elizabeth , Education, Secondary -- South Africa -- Port Elizabeth
- Language: English
- Type: Thesis , Doctoral , DEd
- Identifier: vital:9566 , http://hdl.handle.net/10948/d1016062
- Description: In South Africa, on-going concerns surrounding the development of learners’ literacy, mathematics and science skills are evident and drive various research studies in this field. International studies and assessments, such as the Trends in International Mathematics and Science Study (TIMSS) and the Progress in International Reading Literacy Study (PIRLS) show major differences in the proficiency levels of learners in South Africa in comparison with their international counter parts. To date, however, the more comprehensive international standardised assessment called the Programme for International Student Assessment (PISA), has not been administered in South Africa. The main aim of this research study was to investigate and scientifically explore the real situation in terms of language, mathematics and science literacy knowledge and skills of Grade 9 learners in South Africa and to draw a comparison between Grade 9 learners from secondary schools in the Port Elizabeth district in South Africa and their international counterparts, using the PISA standardised international assessment. In addition, the aim of the study was to determine the actual language, mathematics and science literacy skills and knowledge acquired by participants in this study. Quantitative data collection was done by administering a modified version of the Program for International Student Assessment (PISA) to learners from eight schools in Port Elizabeth, supplemented with questionnaires completed by participating learners and school principals. Findings revealed that the South African learners sampled, ranked in the bottom percentile of participating countries in reading, mathematics and science. The study also exposed the glaring inequalities still prevalent in South African education today, 17 years into democracy. The implications point to a serious investigation into the societal and political factors responsible for the discrepancies in the South African educational system at present.
- Full Text:
- Date Issued: 2012
- Authors: Arnolds, Keith Victor
- Date: 2012
- Subjects: Educational tests and measurements -- South Africa -- Port Elizabeth , Comparative education , Language and languages -- Study and teaching -- South Africa -- Port Elizabeth , Mathematics -- Study and teaching -- South Africa -- Port Elizabeth , Science -- Study and teaching -- South Africa -- Port Elizabeth , Education, Secondary -- South Africa -- Port Elizabeth
- Language: English
- Type: Thesis , Doctoral , DEd
- Identifier: vital:9566 , http://hdl.handle.net/10948/d1016062
- Description: In South Africa, on-going concerns surrounding the development of learners’ literacy, mathematics and science skills are evident and drive various research studies in this field. International studies and assessments, such as the Trends in International Mathematics and Science Study (TIMSS) and the Progress in International Reading Literacy Study (PIRLS) show major differences in the proficiency levels of learners in South Africa in comparison with their international counter parts. To date, however, the more comprehensive international standardised assessment called the Programme for International Student Assessment (PISA), has not been administered in South Africa. The main aim of this research study was to investigate and scientifically explore the real situation in terms of language, mathematics and science literacy knowledge and skills of Grade 9 learners in South Africa and to draw a comparison between Grade 9 learners from secondary schools in the Port Elizabeth district in South Africa and their international counterparts, using the PISA standardised international assessment. In addition, the aim of the study was to determine the actual language, mathematics and science literacy skills and knowledge acquired by participants in this study. Quantitative data collection was done by administering a modified version of the Program for International Student Assessment (PISA) to learners from eight schools in Port Elizabeth, supplemented with questionnaires completed by participating learners and school principals. Findings revealed that the South African learners sampled, ranked in the bottom percentile of participating countries in reading, mathematics and science. The study also exposed the glaring inequalities still prevalent in South African education today, 17 years into democracy. The implications point to a serious investigation into the societal and political factors responsible for the discrepancies in the South African educational system at present.
- Full Text:
- Date Issued: 2012
A comparative study of the life histories of the sister species, Pseudobarbus afer and Pseudobarbus asper, in the Gamtoos River system, South Africa
- Authors: Cambray, James Alfred
- Date: 1993
- Subjects: Barbus -- Life cycles , Barbus -- Ecology -- South Africa -- Gamtoos River , Cyprinidae -- Life cycles , Cyprinidae -- Ecology -- South Africa -- Gamtoos River , Minnows -- Life cycles , Minnows -- Ecology -- South Africa -- Gamtoos River
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5375 , http://hdl.handle.net/10962/d1015730
- Description: This thesis explores the biology, ecology, and life-history styles of two closely-related redfin minnows, Pseudobarbus afer and P. asper (pisces; Cyprinidae), which both occur in the Gamtoos River system of South Africa. Five of the seven species of flexible-rayed redfin minnows are in the South African Red Data Book - Fishes. This investigation was designed to provide the data which would enable conservation authorities to manage the remaining populations of the Pseudobarbus species. A thorough understanding of the Gamtoos River system was necessary to properly interpret the findings of this study. The palaeo river systems and the changing climates since the break-up of Gondwanaland are discussed so that the present day environments could be considered as well as the past environmental changes. P. afer and P. asper occur in the Gamtoos River system with no physical barrier separating the two species. P. afer only occurs in the clear mountain streams of the Cape Fold Mountain Belt whereas P. asper occurs in the highly saline and turbid Karoo section of the system. P. afer were found to be the more precocial form of the sister species. They had bigger eggs, lower relative fecundity, shorter breeding season, lower gonadosomatic indices, larger first feeding larval fish, matured later and had a longer life-span than did P. asper, which had more altricial life-history attributes. They differ in their tradeoffs with P. asper devoting more resources earlier to reproduction and having a shorter lifespan. The improvement in the one aspect of fitness (early maturity) leads to the deterioration in another, namely lifespan. Both species undertake breeding migrations to riffle areas where they spawn in mid-channel immediately above a pool after an increase in water flow. P. afer and P. asper are non-guarders of their non-adhesive eggs and young, open substrate spawners on coarse substrates (rocks) and have photophobic free embryos. The breeding season is shorter for P. afer whereas P. asper can spawn as late as April and impoundment releases can induce them to spawn. A study of comparative neuroecology revealed that of the four groups of fish analyzed (males and females of both species) male P. afer had the largest brains, especially the optic lobes and cerebellum. P. asper females had the smallest brains. No neural compensation in the external gustatory centre, the facial lobe, was found for P. asper inhabiting the turbid waters. P. afer also had significantly larger eyes and longer barbels. P. afer males were also found to have the highest density and largest nuptial tubercles as well as the most pronounced breeding colouration. It was concluded that P. asper is the more derived of the sister species pair with regard to life-history attributes. It is further suggested that investment per offspring is important in determining the life-history trajectories. Paedomorphosis has occurred and by this mechanism variability has been restored to the redfin minnows in the Groot River which enables them to survive in the highly variable, intermittent Karoo stream. The more precocial P. afer do not require this variability in the more constant and predictable environment of the Wit River.
- Full Text:
- Date Issued: 1993
- Authors: Cambray, James Alfred
- Date: 1993
- Subjects: Barbus -- Life cycles , Barbus -- Ecology -- South Africa -- Gamtoos River , Cyprinidae -- Life cycles , Cyprinidae -- Ecology -- South Africa -- Gamtoos River , Minnows -- Life cycles , Minnows -- Ecology -- South Africa -- Gamtoos River
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5375 , http://hdl.handle.net/10962/d1015730
- Description: This thesis explores the biology, ecology, and life-history styles of two closely-related redfin minnows, Pseudobarbus afer and P. asper (pisces; Cyprinidae), which both occur in the Gamtoos River system of South Africa. Five of the seven species of flexible-rayed redfin minnows are in the South African Red Data Book - Fishes. This investigation was designed to provide the data which would enable conservation authorities to manage the remaining populations of the Pseudobarbus species. A thorough understanding of the Gamtoos River system was necessary to properly interpret the findings of this study. The palaeo river systems and the changing climates since the break-up of Gondwanaland are discussed so that the present day environments could be considered as well as the past environmental changes. P. afer and P. asper occur in the Gamtoos River system with no physical barrier separating the two species. P. afer only occurs in the clear mountain streams of the Cape Fold Mountain Belt whereas P. asper occurs in the highly saline and turbid Karoo section of the system. P. afer were found to be the more precocial form of the sister species. They had bigger eggs, lower relative fecundity, shorter breeding season, lower gonadosomatic indices, larger first feeding larval fish, matured later and had a longer life-span than did P. asper, which had more altricial life-history attributes. They differ in their tradeoffs with P. asper devoting more resources earlier to reproduction and having a shorter lifespan. The improvement in the one aspect of fitness (early maturity) leads to the deterioration in another, namely lifespan. Both species undertake breeding migrations to riffle areas where they spawn in mid-channel immediately above a pool after an increase in water flow. P. afer and P. asper are non-guarders of their non-adhesive eggs and young, open substrate spawners on coarse substrates (rocks) and have photophobic free embryos. The breeding season is shorter for P. afer whereas P. asper can spawn as late as April and impoundment releases can induce them to spawn. A study of comparative neuroecology revealed that of the four groups of fish analyzed (males and females of both species) male P. afer had the largest brains, especially the optic lobes and cerebellum. P. asper females had the smallest brains. No neural compensation in the external gustatory centre, the facial lobe, was found for P. asper inhabiting the turbid waters. P. afer also had significantly larger eyes and longer barbels. P. afer males were also found to have the highest density and largest nuptial tubercles as well as the most pronounced breeding colouration. It was concluded that P. asper is the more derived of the sister species pair with regard to life-history attributes. It is further suggested that investment per offspring is important in determining the life-history trajectories. Paedomorphosis has occurred and by this mechanism variability has been restored to the redfin minnows in the Groot River which enables them to survive in the highly variable, intermittent Karoo stream. The more precocial P. afer do not require this variability in the more constant and predictable environment of the Wit River.
- Full Text:
- Date Issued: 1993
A comparison of programming notations for a tertiary level introductory programming course
- Authors: Cilliers, Charmain Barbara
- Date: 2004
- Subjects: Computer programming -- Study and teaching (Higher) -- South Africa , Computer programmers -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:11093 , http://hdl.handle.net/10948/d1019679
- Description: Increasing pressure from national government to improve throughput at South African tertiary education institutions presents challenges to educators of introductory programming courses. In response, educators must adopt effective methods and strategies that encourage novice programmers to be successful in such courses. An approach that seeks to increase and maintain satisfactory throughput is the modification of the teaching model in these courses by adjusting presentation techniques. This thesis investigates the effect of integrating an experimental iconic programming notation and associated development environment with existing conventional textual technological support in the teaching model of a tertiary level introductory programming course. The investigation compares the performance achievement of novice programmers using only conventional textual technological support with that of novice programmers using the integrated iconic and conventional textual technological support. In preparation for the investigation, interpretation of existing knowledge on the behaviour of novice programmers while learning to program results in a novel framework of eight novice programmer requirements for technological support in an introductory programming course. This framework is applied in the examination of existing categories of technological support as well as in the design of new technological support for novice programmers learning to program. It thus provides information for the selection of existing and the design of new introductory programming technological support. The findings of the investigation suggest strong evidence that performance achievement of novice programmers in a tertiary level introductory programming course improves significantly with the inclusion of iconic technological support in the teaching model. The benefits are particularly evident in the portion of the novice programmer population who have been identified as being at risk of being successful in the course. Novice programmers identified as being at risk perform substantially better when using iconic technological support concurrently with conventional textual technological support than their equals who use only the latter form. Considerably more at risk novice programmers using the integrated form of technological support are in fact successful in the introductory programming course when compared with their counterparts who use conventional textual technological support only. The contributions of this thesis address deficiencies existing in current documented research. These contributions are primarily apparent in a number of distinct areas, namely: • formalisation of a novel framework of novice programmer requirements for technological support in an introductory programming course; • application of the framework as a formal evaluation technique; • application of the framework in the design of a visual iconic programming notation and development environment; • enhancement of existing empirical evidence and experimental research methodology typically applied to studies in programming; as well as • a proposal for a modified introductory programming course teaching model. The thesis has effectively applied substantial existing research on the cognitive model of the novice programmer as well as that on experimental technological support. The increase of throughput to a recommended rate of 75 percent in the tertiary level introductory programming course at the University of Port Elizabeth is attributed solely to the incorporation of iconic technological support in the teaching model of the course.
- Full Text:
- Date Issued: 2004
- Authors: Cilliers, Charmain Barbara
- Date: 2004
- Subjects: Computer programming -- Study and teaching (Higher) -- South Africa , Computer programmers -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:11093 , http://hdl.handle.net/10948/d1019679
- Description: Increasing pressure from national government to improve throughput at South African tertiary education institutions presents challenges to educators of introductory programming courses. In response, educators must adopt effective methods and strategies that encourage novice programmers to be successful in such courses. An approach that seeks to increase and maintain satisfactory throughput is the modification of the teaching model in these courses by adjusting presentation techniques. This thesis investigates the effect of integrating an experimental iconic programming notation and associated development environment with existing conventional textual technological support in the teaching model of a tertiary level introductory programming course. The investigation compares the performance achievement of novice programmers using only conventional textual technological support with that of novice programmers using the integrated iconic and conventional textual technological support. In preparation for the investigation, interpretation of existing knowledge on the behaviour of novice programmers while learning to program results in a novel framework of eight novice programmer requirements for technological support in an introductory programming course. This framework is applied in the examination of existing categories of technological support as well as in the design of new technological support for novice programmers learning to program. It thus provides information for the selection of existing and the design of new introductory programming technological support. The findings of the investigation suggest strong evidence that performance achievement of novice programmers in a tertiary level introductory programming course improves significantly with the inclusion of iconic technological support in the teaching model. The benefits are particularly evident in the portion of the novice programmer population who have been identified as being at risk of being successful in the course. Novice programmers identified as being at risk perform substantially better when using iconic technological support concurrently with conventional textual technological support than their equals who use only the latter form. Considerably more at risk novice programmers using the integrated form of technological support are in fact successful in the introductory programming course when compared with their counterparts who use conventional textual technological support only. The contributions of this thesis address deficiencies existing in current documented research. These contributions are primarily apparent in a number of distinct areas, namely: • formalisation of a novel framework of novice programmer requirements for technological support in an introductory programming course; • application of the framework as a formal evaluation technique; • application of the framework in the design of a visual iconic programming notation and development environment; • enhancement of existing empirical evidence and experimental research methodology typically applied to studies in programming; as well as • a proposal for a modified introductory programming course teaching model. The thesis has effectively applied substantial existing research on the cognitive model of the novice programmer as well as that on experimental technological support. The increase of throughput to a recommended rate of 75 percent in the tertiary level introductory programming course at the University of Port Elizabeth is attributed solely to the incorporation of iconic technological support in the teaching model of the course.
- Full Text:
- Date Issued: 2004
A comparison of the aquaculture potential of Clarias gariepinus (Burchell, 1822) and its hybrid with Heterobranchus longifilis valenciennes, 1840 in Southern Africa
- Authors: Oellermann, Lawrence Keith
- Date: 1996
- Subjects: Aquaculture -- South Africa Clarias Clariidae Catfishes -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5246 , http://hdl.handle.net/10962/d1005089
- Description: The aim of this study was to evaluate the aquaculture potential of a hybrid between the two largest African silurid catfish, Heterobranchus longifilis (HL) and Clarias gariepinus (CG) . A morphometric, meristic and karyological study showed that the hybrid shared some of the physical characteristics of both C. gariepinus and H. longifilis, while its chromosome complement and fundamental number (2N = 54, FN = 95), was intermediate between that of H. longifilis (2N = 52, FN = 92) and C. gariepinus (2N = 56, FN = 97). The HLxCG cross could therefore be regarded as a true hybrid. For the characters tested, no morphological or karyological differences were apparent between the HLxCG hybrids produced in West Africa and those produced in southern Africa. In southern Africa, the HL♂xCG♀ cross had higher fertilization and hatching rates than pure strain H. longifilis, C. gariepinus or the reverse cross. There was no difference in the survival of the HL♂xCG♀ hybrid larvae and C. gariepinus larvae up to the onset of exogenous feeding. Pure strain H. longifilis juveniles had a faster growth rate than the H. longifilis ♂ x C. gariepinus ♀ juveniles, but the hybrid always grew at a faster rate than C. gariepinus or the reverse cross. The HL♂xCG♀ cross was consequently chosen as the hybrid with the greatest potential for siluroid aquaculture in southern Africa. The HL♂xCG♀ hybrid showed evidence of partial gonadic, gametic and post-zygotic sterility in both sexes. The hybrid was not completely sterile, as it was artificially induced to spawn, and a small number of viable F₂ hybrid and F₁ hybrid x C. gariepinus larvae were produced. However, in the light of its probable reproductive strategy, it is highly unlikely that the hybrid would pose an ecological risk to the southern African region. The H. longifilis ♂ x C. gariepinus ♀ hybrid was compared to C. gariepinus for selected water quality preferences and tolerances. The hybrid had a wider temperature preference (28 °C to 34 °C) than C. gariepinus (28 °C to 30 °C), but appeared to be more dependent on aerial respiration than C. gariepinus. The air-breathing frequency of hybrid fish began to increase at dissolved oxygen concentrations below 3 .8 mg.ℓ⁻¹, while C. gariepinus only showed an increase in air-breathing frequency at concentrations below 3.0 mg.ℓ¹. The hybrid was more tolerant of un-ionised ammonia (96-hour LC₅₀ = 9.1 mg.ℓ⁻¹) than C. gariepinus (96-hour LC₅₀ = 6.5 mg.ℓ⁻¹), but their 96-hour LC₅₀ salinity tolerances were similar (10.8-11.0 g.ℓ⁻¹). The H. longifilis ♂ x C. gariepinus ♀ hybrid had a higher fillet yield (43.9 %) than C. gariepinus (38.9 %), but the crude protein content and amino acid profile of the two groups were similar. Catfish are traditionally grown in earthen ponds under semi-intensive conditions in southern Africa, at around 4 kg of fish per cubic meter of water (kg.m⁻³). However, the hybrid could tolerate densities of up to 415 kg of fish per cubic metre of water, if the water was exchanged hourly (kg.m⁻³.hr⁻¹), and the density at which yield was optimised was rounded off to 400 kg.m³.hr⁻¹. The high threshold density and water quality tolerances of the H. longifilis ♂ x C. gariepinus ♀ hybrid indicates that it is ideally suited for highly intensive aquaculture. It was concluded that it would be more productive to farm the HL♂xCG♀ hybrid on an intensive basis in southern Africa, than it would be to farm C. gariepinus in the traditional manner.
- Full Text:
- Date Issued: 1996
- Authors: Oellermann, Lawrence Keith
- Date: 1996
- Subjects: Aquaculture -- South Africa Clarias Clariidae Catfishes -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5246 , http://hdl.handle.net/10962/d1005089
- Description: The aim of this study was to evaluate the aquaculture potential of a hybrid between the two largest African silurid catfish, Heterobranchus longifilis (HL) and Clarias gariepinus (CG) . A morphometric, meristic and karyological study showed that the hybrid shared some of the physical characteristics of both C. gariepinus and H. longifilis, while its chromosome complement and fundamental number (2N = 54, FN = 95), was intermediate between that of H. longifilis (2N = 52, FN = 92) and C. gariepinus (2N = 56, FN = 97). The HLxCG cross could therefore be regarded as a true hybrid. For the characters tested, no morphological or karyological differences were apparent between the HLxCG hybrids produced in West Africa and those produced in southern Africa. In southern Africa, the HL♂xCG♀ cross had higher fertilization and hatching rates than pure strain H. longifilis, C. gariepinus or the reverse cross. There was no difference in the survival of the HL♂xCG♀ hybrid larvae and C. gariepinus larvae up to the onset of exogenous feeding. Pure strain H. longifilis juveniles had a faster growth rate than the H. longifilis ♂ x C. gariepinus ♀ juveniles, but the hybrid always grew at a faster rate than C. gariepinus or the reverse cross. The HL♂xCG♀ cross was consequently chosen as the hybrid with the greatest potential for siluroid aquaculture in southern Africa. The HL♂xCG♀ hybrid showed evidence of partial gonadic, gametic and post-zygotic sterility in both sexes. The hybrid was not completely sterile, as it was artificially induced to spawn, and a small number of viable F₂ hybrid and F₁ hybrid x C. gariepinus larvae were produced. However, in the light of its probable reproductive strategy, it is highly unlikely that the hybrid would pose an ecological risk to the southern African region. The H. longifilis ♂ x C. gariepinus ♀ hybrid was compared to C. gariepinus for selected water quality preferences and tolerances. The hybrid had a wider temperature preference (28 °C to 34 °C) than C. gariepinus (28 °C to 30 °C), but appeared to be more dependent on aerial respiration than C. gariepinus. The air-breathing frequency of hybrid fish began to increase at dissolved oxygen concentrations below 3 .8 mg.ℓ⁻¹, while C. gariepinus only showed an increase in air-breathing frequency at concentrations below 3.0 mg.ℓ¹. The hybrid was more tolerant of un-ionised ammonia (96-hour LC₅₀ = 9.1 mg.ℓ⁻¹) than C. gariepinus (96-hour LC₅₀ = 6.5 mg.ℓ⁻¹), but their 96-hour LC₅₀ salinity tolerances were similar (10.8-11.0 g.ℓ⁻¹). The H. longifilis ♂ x C. gariepinus ♀ hybrid had a higher fillet yield (43.9 %) than C. gariepinus (38.9 %), but the crude protein content and amino acid profile of the two groups were similar. Catfish are traditionally grown in earthen ponds under semi-intensive conditions in southern Africa, at around 4 kg of fish per cubic meter of water (kg.m⁻³). However, the hybrid could tolerate densities of up to 415 kg of fish per cubic metre of water, if the water was exchanged hourly (kg.m⁻³.hr⁻¹), and the density at which yield was optimised was rounded off to 400 kg.m³.hr⁻¹. The high threshold density and water quality tolerances of the H. longifilis ♂ x C. gariepinus ♀ hybrid indicates that it is ideally suited for highly intensive aquaculture. It was concluded that it would be more productive to farm the HL♂xCG♀ hybrid on an intensive basis in southern Africa, than it would be to farm C. gariepinus in the traditional manner.
- Full Text:
- Date Issued: 1996
A comparison of the female characters in Plautus and in Terence
- Authors: Slatter, E M
- Date: 1966
- Subjects: Plautus, Titus Maccius Terence Plautus, Titus Maccius -- Characters -- Women Terence -- Characters -- Women Latin drama Women in literature
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3602 , http://hdl.handle.net/10962/d1002186
- Full Text:
- Date Issued: 1966
- Authors: Slatter, E M
- Date: 1966
- Subjects: Plautus, Titus Maccius Terence Plautus, Titus Maccius -- Characters -- Women Terence -- Characters -- Women Latin drama Women in literature
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3602 , http://hdl.handle.net/10962/d1002186
- Full Text:
- Date Issued: 1966
A comparison of the performance of selected conceptual models of the rainfall-runoff process in semi-arid catchments near Grahamstown
- Authors: Roberts, Peter J T
- Date: 1979
- Subjects: Runoff , Rainfall , South Africa , Grahamstown
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4798 , http://hdl.handle.net/10962/d1001898
- Description: A comparison of the performance of selected conceptual models of the rainfall-runoff process forms the central theme of this study and the comparison was conducted with three major objectives in mind. The first objective was to develop a conceptual model that could be used by practising hydrologists for the refinement and extension of historical streamflow records. The major requirements of the model were that it should be simple in structure and easy to operate and yet be flexible in terms of complexity of structure and input requirements as well as producing output at a level of accuracy that is competitive with that of the more complex models presently available. A comparison of the performance of the required model with that of other models formed an integral part of the development process. The second objective of the comparative study was to contribute to current knowledge of the criteria used in the selection of a suitable model for a particular application. There are, at present, no reliable guidelines to assist the hydrologist in selecting a suitable model from the wide range of models available and a comparative study would indicate the merits of various forms of model structure. The third objective is associated with the problems that arise when no streamflow data are available for model calibration. One approach is to calibrate the model in a nearby gauged catchment that the hydrologist regards as being 'hydrologically similar' and transferring the model parameter values to the ungauged catchment. Little is known about the feasibility of this parameter transfer process or about the choice of a model for such an application. The third objective was to test the feasibility of the parameter transfer process and to make use of the comparison of model performance to determine the model characteristics that are most suitable for the purpose
- Full Text:
- Date Issued: 1979
- Authors: Roberts, Peter J T
- Date: 1979
- Subjects: Runoff , Rainfall , South Africa , Grahamstown
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4798 , http://hdl.handle.net/10962/d1001898
- Description: A comparison of the performance of selected conceptual models of the rainfall-runoff process forms the central theme of this study and the comparison was conducted with three major objectives in mind. The first objective was to develop a conceptual model that could be used by practising hydrologists for the refinement and extension of historical streamflow records. The major requirements of the model were that it should be simple in structure and easy to operate and yet be flexible in terms of complexity of structure and input requirements as well as producing output at a level of accuracy that is competitive with that of the more complex models presently available. A comparison of the performance of the required model with that of other models formed an integral part of the development process. The second objective of the comparative study was to contribute to current knowledge of the criteria used in the selection of a suitable model for a particular application. There are, at present, no reliable guidelines to assist the hydrologist in selecting a suitable model from the wide range of models available and a comparative study would indicate the merits of various forms of model structure. The third objective is associated with the problems that arise when no streamflow data are available for model calibration. One approach is to calibrate the model in a nearby gauged catchment that the hydrologist regards as being 'hydrologically similar' and transferring the model parameter values to the ungauged catchment. Little is known about the feasibility of this parameter transfer process or about the choice of a model for such an application. The third objective was to test the feasibility of the parameter transfer process and to make use of the comparison of model performance to determine the model characteristics that are most suitable for the purpose
- Full Text:
- Date Issued: 1979
A comprehensive approach to scalability assessment of ICTD projects : a case study of ICT4RED
- Authors: Baduza, Gugulethu Qhawekazi
- Date: 2021-04
- Subjects: To be added
- Language: English
- Type: thesis , text , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/178435 , vital:42939
- Description: Access restricted until April 2023. , Thesis (PhD) -- Faculty of Commerce, Information Systems, 2021
- Full Text:
- Date Issued: 2021-04
- Authors: Baduza, Gugulethu Qhawekazi
- Date: 2021-04
- Subjects: To be added
- Language: English
- Type: thesis , text , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/178435 , vital:42939
- Description: Access restricted until April 2023. , Thesis (PhD) -- Faculty of Commerce, Information Systems, 2021
- Full Text:
- Date Issued: 2021-04
A comprehensive support programme for professional nurses performing HIV counselling and testing at primary health care clinics in the rural Eastern Cape
- Authors: Madolo, Agrinette Nomboniso
- Date: 2019
- Subjects: HIV-positive persons -- Counseling of , AIDS (Disease) -- Patients -- Counseling of Primary health care -- South Africa -- Eastern Cape Community health nursing -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , DCur
- Identifier: http://hdl.handle.net/10948/40746 , vital:36232
- Description: The increase in global rates of human immunodeficiency virus (HIV) and acquired immune deficiency syndrome (AIDS) has had far reaching effects on healthcare services around the world. According to the 2017 statistics released by UNAIDS, South Africa has the largest HIV epidemic in the world. The South African Department of Health provides an HIV counselling and testing (HCT) service to patients in order that they may know their HIV status and endeavours to educate patients so that they may adapt their behaviours and lifestyles. The goal of this study is to develop a support programme for nurses to assist them in coping emotionally with their day-to-day activities when providing HCT services to patients attending primary healthcare clinics. The paradigm used as a lens to view the phenomenon is Kinlaw’s cyclical growth of empowerment theory. The researcher used a qualitative,explorative, descriptive and contextual design. The study involves three phases: (a) empirical research that explores nurses’ experiences of performing HCT in primary healthcare rural clinics, (b) the development of a conceptual framework for a support programme using the survey list of Dickoff et al. (1968:427). (c) the formalisation of the Comprehensive Support Programme to help nurses to cope emotionally with working with HCT on a long-term basis. Chinn and Kramer (2005118) were used to evaluate the programme. . The empirical findings revealed registered nurses experienced HCT both positively and negatively. They felt overwhelmed by the expectation that all patients attending primary healthcare clinics should be offered HCT routinely and the time constraints involved. They described how the emotional trauma attached to HCT affected their work patterns, leading to low productivity, and affected them outside work, leading to stress and sleep disturbances. They feltl disturbed that even when informed, people choose not to adopt safer sex practices and that how patients responded to a positive diagnosis cannot be predicted. Participants showed signs of stress, frustration, despair and sadness because most tested clients show positive test results and the number of clients testing positive is increasing. While participants felt helpless to improve the situation, at the same time, HCT was experienced as rewarding because it enabled diagnosis of medical conditions of which people weree not aware. The goal of the study was achieved with the development and formalisation of an extensive, relevant and applicable Comprehensive Support Programme for implementation for registered nurses to enable them cope emotionally when conducting HCT based on the empirical findings.
- Full Text:
- Date Issued: 2019
- Authors: Madolo, Agrinette Nomboniso
- Date: 2019
- Subjects: HIV-positive persons -- Counseling of , AIDS (Disease) -- Patients -- Counseling of Primary health care -- South Africa -- Eastern Cape Community health nursing -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , DCur
- Identifier: http://hdl.handle.net/10948/40746 , vital:36232
- Description: The increase in global rates of human immunodeficiency virus (HIV) and acquired immune deficiency syndrome (AIDS) has had far reaching effects on healthcare services around the world. According to the 2017 statistics released by UNAIDS, South Africa has the largest HIV epidemic in the world. The South African Department of Health provides an HIV counselling and testing (HCT) service to patients in order that they may know their HIV status and endeavours to educate patients so that they may adapt their behaviours and lifestyles. The goal of this study is to develop a support programme for nurses to assist them in coping emotionally with their day-to-day activities when providing HCT services to patients attending primary healthcare clinics. The paradigm used as a lens to view the phenomenon is Kinlaw’s cyclical growth of empowerment theory. The researcher used a qualitative,explorative, descriptive and contextual design. The study involves three phases: (a) empirical research that explores nurses’ experiences of performing HCT in primary healthcare rural clinics, (b) the development of a conceptual framework for a support programme using the survey list of Dickoff et al. (1968:427). (c) the formalisation of the Comprehensive Support Programme to help nurses to cope emotionally with working with HCT on a long-term basis. Chinn and Kramer (2005118) were used to evaluate the programme. . The empirical findings revealed registered nurses experienced HCT both positively and negatively. They felt overwhelmed by the expectation that all patients attending primary healthcare clinics should be offered HCT routinely and the time constraints involved. They described how the emotional trauma attached to HCT affected their work patterns, leading to low productivity, and affected them outside work, leading to stress and sleep disturbances. They feltl disturbed that even when informed, people choose not to adopt safer sex practices and that how patients responded to a positive diagnosis cannot be predicted. Participants showed signs of stress, frustration, despair and sadness because most tested clients show positive test results and the number of clients testing positive is increasing. While participants felt helpless to improve the situation, at the same time, HCT was experienced as rewarding because it enabled diagnosis of medical conditions of which people weree not aware. The goal of the study was achieved with the development and formalisation of an extensive, relevant and applicable Comprehensive Support Programme for implementation for registered nurses to enable them cope emotionally when conducting HCT based on the empirical findings.
- Full Text:
- Date Issued: 2019
A comprehensive university: constructing an organisational identity
- Authors: Moeng, Siphokazi Florence
- Date: 2009
- Subjects: Universities and colleges -- Mergers -- South Africa -- Port Elizabeth , Educational change -- South Africa -- Port Elizabeth , Education, Higher -- South Africa -- Port Elizabeth -- Aims and objectives , Organizational behavior -- South Africa -- Port Elizabeth
- Language: English
- Type: Thesis , Doctoral , DEd
- Identifier: vital:9517 , http://hdl.handle.net/10948/1029 , Universities and colleges -- Mergers -- South Africa -- Port Elizabeth , Educational change -- South Africa -- Port Elizabeth , Education, Higher -- South Africa -- Port Elizabeth -- Aims and objectives , Organizational behavior -- South Africa -- Port Elizabeth
- Description: The restructuring of higher education through incorporations and mergers has attracted a lot of attention over the past few years in South Africa. These incorporations and mergers have displaced institutions of higher education and positioned them in new organisational homes, thus subjecting faculties, schools and departments to a process of relocation, new knowledge acquisition, identity change and meaning-making processes. The merger has resulted in three types of universities; i.e. traditional universities, comprehensive universities and universities of technology. The introduction of the comprehensive university as a new institutional type has brought with it questions about the idea of the university and the purpose of higher education in general. Mergers in particular have initiated conversations about sense-making and meaning during change. Amidst all this, people within the merging institution have been confronted with a new organisation with which they have to identify. At universities in particular, questions about academic identity and organisational identity have become unavoidable. The boundaries that gave definition to a university have been (re)moved. The structure of the university, as it was known, has changed. Hence, in the newly merged NMMU, academics are in the process of internalising and giving meaning to the new organisational values and norms of a comprehensive university. Needless to say, the challenges facing the newly merged NMMU are cultural, structural and geographic. Bringing together different institutional and personal cultures involves a human dimension that needs to be nurtured by trying to form a coherent and cohesive organisation that is created from culturally diverse and uncomplementary institutions. Another challenge is bringing together different organisational structures, systems and programmes that are informed by different institutional cultures. Furthermore, the challenge of having multiple campuses that are geographically separated exacerbates the situation. Along with all these challenges, the NMMU has the task of constructing an integrated institutional identity through organisational forms and programme models that will embody the multiple functions that are typical of a comprehensive university. The aim of the current study was to explore how the meanings that academics assign to the notion of a comprehensive university are instrumental in constructing an organisational identity; describing in detail how at the NMMU academics make meaning of the comprehensive university and how that meaning-making process influences the construction of an organisational identity; and formulating recommendations based on the qualitative findings and quantitative results of the research. In an effort to achieve the aim alluded to above, this study employed the mixed methods approach that used a sequential, exploratory, transformative design. The complexity of the study was such that it required to be investigated through qualitative and quantitative analytical methods in order to confirm, triangulate and obtain a holistic picture of the situation under investigation. The sample for the qualitative interviews consisted of thirteen purposefully selected academics from all levels at the NMMU. The interviews were transcribed and coded into themes, categories and sub-categories. These themes were then developed and translated into statements for the questionnaire that was administered randomly to all NMMU academics. A total of 108 academics responded to the questionnaire. The responses to the questionnaire were analysed using the SPSS programme. The findings and results of the study revealed that there was a fairly common understanding of the term comprehensive university among academics. However, the details about its procedures appeared to be the privileged ownership of management. This situation mitigated the necessity for a sense-making process that would allow for negotiation, modification and alteration of already held assumptions. A pertinent concern amongst academics was the neglect of the ‘human factor’ during the change process. The management style also came under scrutiny, especially in terms of the facilitation and mediation of change. There was a consensus on the call for cohesion and unity that was believed to be one of the main features that would make the construction of the NMMU organisational identity possible. The vision, mission and values of the NMMU were believed to be central to the creation of cohesion and unity, which would subsequently result in the birth of an organisational culture that could inform the organisational identity of the NMMU. Strategies to actualise and realise the organisational identity were proposed by participants. Notwithstanding, the impact of the merger was identified as having a major influence in shaping the organisational identity of the NMMU.
- Full Text:
- Date Issued: 2009
- Authors: Moeng, Siphokazi Florence
- Date: 2009
- Subjects: Universities and colleges -- Mergers -- South Africa -- Port Elizabeth , Educational change -- South Africa -- Port Elizabeth , Education, Higher -- South Africa -- Port Elizabeth -- Aims and objectives , Organizational behavior -- South Africa -- Port Elizabeth
- Language: English
- Type: Thesis , Doctoral , DEd
- Identifier: vital:9517 , http://hdl.handle.net/10948/1029 , Universities and colleges -- Mergers -- South Africa -- Port Elizabeth , Educational change -- South Africa -- Port Elizabeth , Education, Higher -- South Africa -- Port Elizabeth -- Aims and objectives , Organizational behavior -- South Africa -- Port Elizabeth
- Description: The restructuring of higher education through incorporations and mergers has attracted a lot of attention over the past few years in South Africa. These incorporations and mergers have displaced institutions of higher education and positioned them in new organisational homes, thus subjecting faculties, schools and departments to a process of relocation, new knowledge acquisition, identity change and meaning-making processes. The merger has resulted in three types of universities; i.e. traditional universities, comprehensive universities and universities of technology. The introduction of the comprehensive university as a new institutional type has brought with it questions about the idea of the university and the purpose of higher education in general. Mergers in particular have initiated conversations about sense-making and meaning during change. Amidst all this, people within the merging institution have been confronted with a new organisation with which they have to identify. At universities in particular, questions about academic identity and organisational identity have become unavoidable. The boundaries that gave definition to a university have been (re)moved. The structure of the university, as it was known, has changed. Hence, in the newly merged NMMU, academics are in the process of internalising and giving meaning to the new organisational values and norms of a comprehensive university. Needless to say, the challenges facing the newly merged NMMU are cultural, structural and geographic. Bringing together different institutional and personal cultures involves a human dimension that needs to be nurtured by trying to form a coherent and cohesive organisation that is created from culturally diverse and uncomplementary institutions. Another challenge is bringing together different organisational structures, systems and programmes that are informed by different institutional cultures. Furthermore, the challenge of having multiple campuses that are geographically separated exacerbates the situation. Along with all these challenges, the NMMU has the task of constructing an integrated institutional identity through organisational forms and programme models that will embody the multiple functions that are typical of a comprehensive university. The aim of the current study was to explore how the meanings that academics assign to the notion of a comprehensive university are instrumental in constructing an organisational identity; describing in detail how at the NMMU academics make meaning of the comprehensive university and how that meaning-making process influences the construction of an organisational identity; and formulating recommendations based on the qualitative findings and quantitative results of the research. In an effort to achieve the aim alluded to above, this study employed the mixed methods approach that used a sequential, exploratory, transformative design. The complexity of the study was such that it required to be investigated through qualitative and quantitative analytical methods in order to confirm, triangulate and obtain a holistic picture of the situation under investigation. The sample for the qualitative interviews consisted of thirteen purposefully selected academics from all levels at the NMMU. The interviews were transcribed and coded into themes, categories and sub-categories. These themes were then developed and translated into statements for the questionnaire that was administered randomly to all NMMU academics. A total of 108 academics responded to the questionnaire. The responses to the questionnaire were analysed using the SPSS programme. The findings and results of the study revealed that there was a fairly common understanding of the term comprehensive university among academics. However, the details about its procedures appeared to be the privileged ownership of management. This situation mitigated the necessity for a sense-making process that would allow for negotiation, modification and alteration of already held assumptions. A pertinent concern amongst academics was the neglect of the ‘human factor’ during the change process. The management style also came under scrutiny, especially in terms of the facilitation and mediation of change. There was a consensus on the call for cohesion and unity that was believed to be one of the main features that would make the construction of the NMMU organisational identity possible. The vision, mission and values of the NMMU were believed to be central to the creation of cohesion and unity, which would subsequently result in the birth of an organisational culture that could inform the organisational identity of the NMMU. Strategies to actualise and realise the organisational identity were proposed by participants. Notwithstanding, the impact of the merger was identified as having a major influence in shaping the organisational identity of the NMMU.
- Full Text:
- Date Issued: 2009
A computational analysis to decipher the pathways of stability, uncoating and antigenicity of human enterovirus capsids
- Authors: Ross, Caroline Jane
- Date: 2019
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/114788 , vital:34035 , 10.21504/10962/114788
- Description: Expected release date-April 2021
- Full Text: false
- Date Issued: 2019
- Authors: Ross, Caroline Jane
- Date: 2019
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/114788 , vital:34035 , 10.21504/10962/114788
- Description: Expected release date-April 2021
- Full Text: false
- Date Issued: 2019
A conductimetric investigation of phenomena in extremely dilute aqueous solutions
- Authors: Faure, Pierre Knobel
- Date: 1957
- Subjects: Adsorption , Solution (Chemistry)
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4524 , http://hdl.handle.net/10962/d1014891
- Description: 1. The apparatus used in this investigation is fully described, and a new method is outlined for the calibration of bridge resistances "in situ". 2. A chart is given for the accurate correction of weights in air to weights in vacuum for a range of temperatures extending from 10° to 28°C, and for pressures from 690 to 730 mm. 3. An automatic recycling still has been designed for the continuous production of "ultra-pure" water. This still is capable of delivering daily, in routine operation, 16 l. of water of conductivity less than 100 nm/cm after aeration with "C0₂- and NH₃-free" air. 4. A very soluble layer appears to form on the surface of' glass when it is dried; this layer is readily removed on contact with water. 5. The removal of carbon dioxide and of ammonia from aqueous solution by aeration with an indifferent gas has been fully investigated, and it has been shown that these gases can be completely eliminated by such a process. Whereas the carbon dioxide is removed fairly rapidly, however, the ammonia, whether present alone or together with carbon dioxide, only goes out of solution rather slowly. 6. It has been shown that ammonia is adsorbed from aqueous solution on the glass walls of the cell. 7. There does not appear to be any ammonium bicarbonate in the residual impurity left in the "ultra-pure" water obtained from the still; the impurity can, in fact, be regarded as neutral salt with sufficient accuracy for most purposes. 8. The resistance change which accompanies any variation in the rate of bubbling of the stirring gas through the water has been investigated, but no solution has been found as to the cause of this change. 9. A comparison has been made of the efficiency of different gases for stirring purposes, and it seems that, for general work, nitrogen is by far the most suitable of the common gases. 10. The extrapolation to be used for converting resistances to their values at infinite frequency appears ...
- Full Text:
- Date Issued: 1957
- Authors: Faure, Pierre Knobel
- Date: 1957
- Subjects: Adsorption , Solution (Chemistry)
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4524 , http://hdl.handle.net/10962/d1014891
- Description: 1. The apparatus used in this investigation is fully described, and a new method is outlined for the calibration of bridge resistances "in situ". 2. A chart is given for the accurate correction of weights in air to weights in vacuum for a range of temperatures extending from 10° to 28°C, and for pressures from 690 to 730 mm. 3. An automatic recycling still has been designed for the continuous production of "ultra-pure" water. This still is capable of delivering daily, in routine operation, 16 l. of water of conductivity less than 100 nm/cm after aeration with "C0₂- and NH₃-free" air. 4. A very soluble layer appears to form on the surface of' glass when it is dried; this layer is readily removed on contact with water. 5. The removal of carbon dioxide and of ammonia from aqueous solution by aeration with an indifferent gas has been fully investigated, and it has been shown that these gases can be completely eliminated by such a process. Whereas the carbon dioxide is removed fairly rapidly, however, the ammonia, whether present alone or together with carbon dioxide, only goes out of solution rather slowly. 6. It has been shown that ammonia is adsorbed from aqueous solution on the glass walls of the cell. 7. There does not appear to be any ammonium bicarbonate in the residual impurity left in the "ultra-pure" water obtained from the still; the impurity can, in fact, be regarded as neutral salt with sufficient accuracy for most purposes. 8. The resistance change which accompanies any variation in the rate of bubbling of the stirring gas through the water has been investigated, but no solution has been found as to the cause of this change. 9. A comparison has been made of the efficiency of different gases for stirring purposes, and it seems that, for general work, nitrogen is by far the most suitable of the common gases. 10. The extrapolation to be used for converting resistances to their values at infinite frequency appears ...
- Full Text:
- Date Issued: 1957
A conscious leadership model to achieve sustainable business practices
- Sukhdeo, Beverley Amanda Faith
- Authors: Sukhdeo, Beverley Amanda Faith
- Date: 2015
- Subjects: Industrial management -- Environmental aspects , Sustainable development , Social responsibility of business
- Language: English
- Type: Thesis , Doctoral , DBA
- Identifier: http://hdl.handle.net/10948/5885 , vital:21008
- Description: Business sustainability is a fundamental concern amongst business leaders and it is imperative that business defines an environmentally and socially sustainable path to financial prosperity. This focus on sustainable business practices has been caused by the perceived contribution of businesses to undesirable conditions such as environmental and social degradation including global warming and the global financial crises. This study suggests that a leadership style that differs from leadership that is currently causing business unsustainability is needed in order to achieve the goal of sustainable business practices. This study therefore proposes a new kind of leadership, called conscious leadership. The main contribution of the study is to increase the achievement of sustainable business practices by investigating the importance of conscious leadership in achieving this objective. Convenience sampling was used to select senior managers and directors from mainly JSE listed companies. This resulted in a total of 371 usable questionnaires (317 from listed companies and 54 from unlisted companies) being received. A quantitative approach was adopted to investigate whether conscious leadership would be related to increased sustainability competencies and more effective sustainability-related corporate governance and whether these in turn would increase sustainability behaviours which would generate sustainable business practices as measured by financial, social and environmental performance. Regression analyses were conducted to investigate the hypothesised relationships among these variables. Pearson correlations and descriptive statistics were also calculated. The empirical results showed that respondents in this study regarded conscious leadership, not as a separate construct, but as a way they governed their businesses. The empirical results showed that corporate governance and systems thinking competency had a strong interactive relationship and should therefore be cultivated within business firms. Corporate governance (including conscious leadership) and systems-thinking competency were positive influencers of employee relations, equal opportunities and workforce diversity. The empirical results however showed that corporate governance (including conscious leadership) had a negative influence on profitability. The present study cannot argue for the discouragement of corporate governance (including conscious leadership), as measured in this study, because reduced corporate governance would decrease healthy employee relations and the latter would decrease the achievement of equal opportunities and workforce diversity in these firms. A decrease in healthy employee relations would decrease profitability. The most important finding of this study is that senior managers and directors of big business firms, mostly JSE-listed companies, regarded conscious leadership as an important part of corporate governance. Corporate governance that includes conscious leadership must be developed to higher levels in business firms, so that the negative and not-significant relationships to profitability as viewed by lower and high conscious leaders respectively can be changed to positive relationships.
- Full Text:
- Date Issued: 2015
- Authors: Sukhdeo, Beverley Amanda Faith
- Date: 2015
- Subjects: Industrial management -- Environmental aspects , Sustainable development , Social responsibility of business
- Language: English
- Type: Thesis , Doctoral , DBA
- Identifier: http://hdl.handle.net/10948/5885 , vital:21008
- Description: Business sustainability is a fundamental concern amongst business leaders and it is imperative that business defines an environmentally and socially sustainable path to financial prosperity. This focus on sustainable business practices has been caused by the perceived contribution of businesses to undesirable conditions such as environmental and social degradation including global warming and the global financial crises. This study suggests that a leadership style that differs from leadership that is currently causing business unsustainability is needed in order to achieve the goal of sustainable business practices. This study therefore proposes a new kind of leadership, called conscious leadership. The main contribution of the study is to increase the achievement of sustainable business practices by investigating the importance of conscious leadership in achieving this objective. Convenience sampling was used to select senior managers and directors from mainly JSE listed companies. This resulted in a total of 371 usable questionnaires (317 from listed companies and 54 from unlisted companies) being received. A quantitative approach was adopted to investigate whether conscious leadership would be related to increased sustainability competencies and more effective sustainability-related corporate governance and whether these in turn would increase sustainability behaviours which would generate sustainable business practices as measured by financial, social and environmental performance. Regression analyses were conducted to investigate the hypothesised relationships among these variables. Pearson correlations and descriptive statistics were also calculated. The empirical results showed that respondents in this study regarded conscious leadership, not as a separate construct, but as a way they governed their businesses. The empirical results showed that corporate governance and systems thinking competency had a strong interactive relationship and should therefore be cultivated within business firms. Corporate governance (including conscious leadership) and systems-thinking competency were positive influencers of employee relations, equal opportunities and workforce diversity. The empirical results however showed that corporate governance (including conscious leadership) had a negative influence on profitability. The present study cannot argue for the discouragement of corporate governance (including conscious leadership), as measured in this study, because reduced corporate governance would decrease healthy employee relations and the latter would decrease the achievement of equal opportunities and workforce diversity in these firms. A decrease in healthy employee relations would decrease profitability. The most important finding of this study is that senior managers and directors of big business firms, mostly JSE-listed companies, regarded conscious leadership as an important part of corporate governance. Corporate governance that includes conscious leadership must be developed to higher levels in business firms, so that the negative and not-significant relationships to profitability as viewed by lower and high conscious leaders respectively can be changed to positive relationships.
- Full Text:
- Date Issued: 2015
A constructivist deconstruction of post-apartheid South Africa’s trade negotiation strategies: the politics of development and global value chains
- Authors: Pillay, Morgenie
- Date: 2015
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/64731 , vital:28596
- Description: Expected release date-May 2020
- Full Text:
- Date Issued: 2015
- Authors: Pillay, Morgenie
- Date: 2015
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/64731 , vital:28596
- Description: Expected release date-May 2020
- Full Text:
- Date Issued: 2015
A context-aware model to improve usability of information presented on mobile devices
- Authors: Ntawanga, Felix Fred
- Date: 2014
- Subjects: Context-aware computing , Online information services
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:10495 , http://hdl.handle.net/10948/d1020768
- Description: Online information access on mobile devices is increasing as a result of the growth in the use of Internet-enabled handheld (or pocket-size) devices. The combined influence of recent enabling technologies such as Web 2.0, mobile app stores and improved wireless networks have driven the increase in online applications that allow users to access various types of information on mobile devices regardless of time and location. Examples of such applications (usually shortened to app) include: social media, such as FacebookTM App and TwitterTM App, banking applications such as (Standard Bank South Africa)TM Mobile Banking App and First National Bank (FNB) BankingTM App, and news application such as news 24TM App and BBCTM News App. Online businesses involved in buying, selling and business transaction processing activities via the Internet have exploited the opportunity to extend electronic commerce (e-commerce) initiatives into mobile commerce (m-commerce). Online businesses that interact with end user customers implement business to consumer (B2C) m-commerce applications that enable customers to access and browse product catalogue information on mobile devices, anytime, anywhere. Customers accessing electronic product catalogue information on a mobile device face a number of challenges such as a long list of products presented on a small screen and a longer information download time. These challenges mainly originate from the limiting and dynamic nature of the mobile apps operating environment, for example, dynamic location, bandwidth fluctuations and, diverse and limited device features, collectively referred to as context. The goal of this research was to design and implement a context-aware model that can be incorporated into an m-commerce application in order to improve the presentation of product catalogue information on m-commerce storefronts. The motivation for selecting product catalogue is prompted by literature which indicates that improved presentation of information in m-commerce (and e-commerce) applications has a positive impact on usability of the websites. Usable m-commerce (and e-commerce) websites improve efficiency in consumer behaviour that impacts sales, profits and business growth. The context-aware model aimed at collecting context information within the user environment and utilising it to determine optimal retrieval and presentation of product catalogue in m-commerce. An integrated logical context sensor and Mathematical algorithms were implemented in the context-aware model. The integrated logical context sensor was responsible for the collection of different types of predetermined context information such as device specification or capabilities, connection bandwidth, location and time of the day as well as the user profile. The algorithms transformed the collected context information into usable formats and enabled optimal retrieval and presentation of product catalogue data on a specific mobile device. Open-source implementation tools were utilised to implement components of the model including: HTML5, PhP, JavaScript and MySQL database. The context-aware model was incorporated into an existing m-commerce application. Two user evaluation studies were conducted during the course of the research. The first evaluation was to evaluate the accuracy of information collected by the context sensor component of the model. This survey was conducted with a sample of 30 users from different countries across the world. In-between the context sensor and main evaluation surveys, a pilot study was conducted with a sample of 19 users with great experience in mobile application development and use from SAP Next Business and Technology, Africa. Finally an overall user evaluation study was conducted with a sample of 30 users from a remote area called Kgautswane in Limpopo Province, South Africa. The results obtained indicate that the context-aware model was able to determine accurate context information in real-time and effectively determine how much product information should be retrieved and how the information should be presented on a mobile device interface. Two main contributions emerged from the research, first the research contributed to the field of mobile Human Computer Interaction. During the research, techniques of evaluating and improving usability of mobile applications were demonstrated. Secondly, the research made a significant contribution to the upcoming field of context-aware computing. The research brought clarity with regard to context-aware computing which is lacking in existing, current research despite the field’s proven impact of improving usability of applications. Researchers can utilise contributions made in this research to develop further techniques and usable context-aware solutions.
- Full Text:
- Date Issued: 2014
- Authors: Ntawanga, Felix Fred
- Date: 2014
- Subjects: Context-aware computing , Online information services
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:10495 , http://hdl.handle.net/10948/d1020768
- Description: Online information access on mobile devices is increasing as a result of the growth in the use of Internet-enabled handheld (or pocket-size) devices. The combined influence of recent enabling technologies such as Web 2.0, mobile app stores and improved wireless networks have driven the increase in online applications that allow users to access various types of information on mobile devices regardless of time and location. Examples of such applications (usually shortened to app) include: social media, such as FacebookTM App and TwitterTM App, banking applications such as (Standard Bank South Africa)TM Mobile Banking App and First National Bank (FNB) BankingTM App, and news application such as news 24TM App and BBCTM News App. Online businesses involved in buying, selling and business transaction processing activities via the Internet have exploited the opportunity to extend electronic commerce (e-commerce) initiatives into mobile commerce (m-commerce). Online businesses that interact with end user customers implement business to consumer (B2C) m-commerce applications that enable customers to access and browse product catalogue information on mobile devices, anytime, anywhere. Customers accessing electronic product catalogue information on a mobile device face a number of challenges such as a long list of products presented on a small screen and a longer information download time. These challenges mainly originate from the limiting and dynamic nature of the mobile apps operating environment, for example, dynamic location, bandwidth fluctuations and, diverse and limited device features, collectively referred to as context. The goal of this research was to design and implement a context-aware model that can be incorporated into an m-commerce application in order to improve the presentation of product catalogue information on m-commerce storefronts. The motivation for selecting product catalogue is prompted by literature which indicates that improved presentation of information in m-commerce (and e-commerce) applications has a positive impact on usability of the websites. Usable m-commerce (and e-commerce) websites improve efficiency in consumer behaviour that impacts sales, profits and business growth. The context-aware model aimed at collecting context information within the user environment and utilising it to determine optimal retrieval and presentation of product catalogue in m-commerce. An integrated logical context sensor and Mathematical algorithms were implemented in the context-aware model. The integrated logical context sensor was responsible for the collection of different types of predetermined context information such as device specification or capabilities, connection bandwidth, location and time of the day as well as the user profile. The algorithms transformed the collected context information into usable formats and enabled optimal retrieval and presentation of product catalogue data on a specific mobile device. Open-source implementation tools were utilised to implement components of the model including: HTML5, PhP, JavaScript and MySQL database. The context-aware model was incorporated into an existing m-commerce application. Two user evaluation studies were conducted during the course of the research. The first evaluation was to evaluate the accuracy of information collected by the context sensor component of the model. This survey was conducted with a sample of 30 users from different countries across the world. In-between the context sensor and main evaluation surveys, a pilot study was conducted with a sample of 19 users with great experience in mobile application development and use from SAP Next Business and Technology, Africa. Finally an overall user evaluation study was conducted with a sample of 30 users from a remote area called Kgautswane in Limpopo Province, South Africa. The results obtained indicate that the context-aware model was able to determine accurate context information in real-time and effectively determine how much product information should be retrieved and how the information should be presented on a mobile device interface. Two main contributions emerged from the research, first the research contributed to the field of mobile Human Computer Interaction. During the research, techniques of evaluating and improving usability of mobile applications were demonstrated. Secondly, the research made a significant contribution to the upcoming field of context-aware computing. The research brought clarity with regard to context-aware computing which is lacking in existing, current research despite the field’s proven impact of improving usability of applications. Researchers can utilise contributions made in this research to develop further techniques and usable context-aware solutions.
- Full Text:
- Date Issued: 2014
A contribution to TEC modelling over Southern Africa using GPS data
- Authors: Habarulema, John Bosco
- Date: 2010
- Subjects: Electrons -- Mathematical models Radio wave propagation Global positioning system -- Measurement Ionospheric radio wave propagation Atmospheric physics -- Africa, Southern
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5456 , http://hdl.handle.net/10962/d1005241
- Description: Modelling ionospheric total electron content (TEC) is an important area of interest for radio wave propagation, geodesy, surveying, the understanding of space weather dynamics and error correction in relation to Global Navigation Satellite Systems (GNNS) applications. With the utilisation of improved ionosonde technology coupled with the use of GNSS, the response of technological systems due to changes in the ionosphere during both quiet and disturbed conditions can be historically inferred. TEC values are usually derived from GNSS measurements using mathematically intensive algorithms. However, the techniques used to estimate these TEC values depend heavily on the availability of near-real time GNSS data, and therefore, are sometimes unable to generate complete datasets. This thesis investigated possibilities for the modelling of TEC values derived from the South African Global Positioning System (GPS)receiver network using linear regression methods and artificial neural networks (NNs). GPS TEC values were derived using the Adjusted Spherical Harmonic Analysis (ASHA) algorithm. Considering TEC and the factors that influence its variability as “dependent and independent variables” respectively, the capabilities of linear regression methods and NNs for TEC modelling were first investigated using a small dataset from two GPS receiver stations. NN and regression models were separately developed and used to reproduce TEC fluctuations at different stations not included in the models’ development. For this purpose, TEC was modelled as a function of diurnal variation, seasonal variation, solar and magnetic activities. Comparative analysis showed that NN models provide predictions of GPS TEC that were an improvement on those predicted by the regression models developed. A separate study to empirically investigate the effects of solar wind on GPS TEC was carried out. Quantitative results indicated that solar wind does not have a significant influence on TEC variability. The final TEC simulation model developed makes use of the NN technique to find the relationship between historical TEC data variations and factors that are known to influence TEC variability (such as solar and magnetic activities, diurnal and seasonal variations and the geographical locations of the respective GPS stations) for the purposes of regional TEC modelling and mapping. The NN technique in conjunction with interpolation and extrapolation methods makes it possible to construct ionospheric TEC maps and to analyse the spatial and temporal TEC behaviour over Southern Africa. For independent validation, modelled TEC values were compared to ionosonde TEC and the International Reference Ionosphere (IRI) generated TEC values during both quiet and disturbed conditions. This thesis provides a comprehensive guide on the development of TEC models for predicting ionospheric variability over the South African region, and forms a significant contribution to ionospheric modelling efforts in Africa.
- Full Text:
- Date Issued: 2010
- Authors: Habarulema, John Bosco
- Date: 2010
- Subjects: Electrons -- Mathematical models Radio wave propagation Global positioning system -- Measurement Ionospheric radio wave propagation Atmospheric physics -- Africa, Southern
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5456 , http://hdl.handle.net/10962/d1005241
- Description: Modelling ionospheric total electron content (TEC) is an important area of interest for radio wave propagation, geodesy, surveying, the understanding of space weather dynamics and error correction in relation to Global Navigation Satellite Systems (GNNS) applications. With the utilisation of improved ionosonde technology coupled with the use of GNSS, the response of technological systems due to changes in the ionosphere during both quiet and disturbed conditions can be historically inferred. TEC values are usually derived from GNSS measurements using mathematically intensive algorithms. However, the techniques used to estimate these TEC values depend heavily on the availability of near-real time GNSS data, and therefore, are sometimes unable to generate complete datasets. This thesis investigated possibilities for the modelling of TEC values derived from the South African Global Positioning System (GPS)receiver network using linear regression methods and artificial neural networks (NNs). GPS TEC values were derived using the Adjusted Spherical Harmonic Analysis (ASHA) algorithm. Considering TEC and the factors that influence its variability as “dependent and independent variables” respectively, the capabilities of linear regression methods and NNs for TEC modelling were first investigated using a small dataset from two GPS receiver stations. NN and regression models were separately developed and used to reproduce TEC fluctuations at different stations not included in the models’ development. For this purpose, TEC was modelled as a function of diurnal variation, seasonal variation, solar and magnetic activities. Comparative analysis showed that NN models provide predictions of GPS TEC that were an improvement on those predicted by the regression models developed. A separate study to empirically investigate the effects of solar wind on GPS TEC was carried out. Quantitative results indicated that solar wind does not have a significant influence on TEC variability. The final TEC simulation model developed makes use of the NN technique to find the relationship between historical TEC data variations and factors that are known to influence TEC variability (such as solar and magnetic activities, diurnal and seasonal variations and the geographical locations of the respective GPS stations) for the purposes of regional TEC modelling and mapping. The NN technique in conjunction with interpolation and extrapolation methods makes it possible to construct ionospheric TEC maps and to analyse the spatial and temporal TEC behaviour over Southern Africa. For independent validation, modelled TEC values were compared to ionosonde TEC and the International Reference Ionosphere (IRI) generated TEC values during both quiet and disturbed conditions. This thesis provides a comprehensive guide on the development of TEC models for predicting ionospheric variability over the South African region, and forms a significant contribution to ionospheric modelling efforts in Africa.
- Full Text:
- Date Issued: 2010