Assessment of the impact of land use practices on vegetation , soil and carbon-nitrogen sequestration potential in Mopane rangelands of Central Northern Namibia
- Authors: Kahumba, Absalom
- Date: 2018
- Subjects: Rural development Land use Land tenure
- Language: English
- Type: Thesis , Doctoral , Pasture Science
- Identifier: http://hdl.handle.net/10353/11718 , vital:39100
- Description: This study was conducted in Ogongo district, situated in Omusati Region of the central northern Namibia. The objectives of this study were to assess the impact of land use practices on 1) vegetation distribution and status; 2) soil properties; 3) carbon-nitrogen sequestration potential, and 4) investigate the indigenous pastoralists’ knowledge and perceptions on livestock production, rangeland degradation and its indicators in three villages (Omaandi, Epukunoyana and Oshitutuma) in Mopane savannah rangelands of central northern Namibia. For vegetation and soil assessment, three grazing land management systems (communal, game reserve and cattle ranch) were identified adjacent to each other. In each grazing system, three sites (for game reserve and cattle ranch, these were camps) were selected. In each site, three belt transects of 50 m x 5 m2 were marked to record vegetation and soil data as well as to collect vegetation samples for analysis. Grass species composition was recorded using step point methods from 250 points per belt transect. A total of five 0.25 m2 quadrats were randomly laid within each 250 m2 belt transect to record the herbaceous plant density, tuft diameter, tuft distance and biomass. All woody plants in the belt transect (250 m2) were measured and recorded for species plant height and canopy diameters. Three soil samples per belt transect were collected at the time of forage sampling down to a depth of 20 cm using a soil auger. Soil and plant samples were analysed for macro and micro minerals, total organic carbon, total nitrogen, carbon-nitrogen ratios, and carbon and nitrogen isotopes. For bulk density, soil samples were collected using soil core samplers. In the social study, a total of 90 households were randomly selected from three villages and a total of 48 elders were purposefully selected based on the age, time spent in the village and livestock ownership. A combination of structured and semi-structured questionnaires were used to gather household information, while a structured questionnaire and open ended discussion were used to interview elders on the constraints of livestock production, rangeland degradation related issues and their consequences on livelihood. Field vegetation and soil data were analyzed using a General Linear Model (GLM) in SAS (2007), whereas the social data were analyzed using SPSS version 21 (2014). A total of 23 grass species were identified in all three land management systems, of which 48% were perennials and the remaining 52% were annuals. Aristida meridionalis dominated the game reserve and the ranch, whereas Eragrostis trichophora was dominant in all land management systems. Forbs occurred commonly in the game reserve and the ranch, but were dominant in the communal areas. The abundance of A. meridionalis responded significantly (P < 0.001) to land management systems with the game reserve showing remarkably greater abundance than the ranch. In summer, the abundance of E. trichophora was high (P < 0.001) in the game reserve followed by the communal and ranch sites, whereas in winter, the species had still greater abundance in the game reserve followed by the ranch. In summer, the mean grass density was greatest (P < 0.001) in the game reserve and least in the communal lands, but vice versa for the tuft distance. In summer, the average distance between tufts showed great variations (P < 0.001) with the communal areas having greater values than the ranch and game reserve. In winter, both the game reserve and the ranch showed records of similar grass tuft density and distance between tufts, whereas these values were nil for communal areas, because, there were no grasses recorded. Herbaceous plant dry matter was significantly greater (P < 0.05) in the game reserve followed by the ranch and the least in the communal areas. Results on biomass showed remarkably higher values (P < 0.001) in summer than winter in all land management systems. The total woody plant density was significantly higher (P < 0.001) in the ranch (542 TE ha-1) than the game reserve (449 TE ha-1) and communal area (324 TE ha-1). However, percentage of canopy cover did not differ significantly (P > 0.05) between the three land management systems. Woody plant density of height classes were significantly different (P < 0.05) between three land management systems. The abundance of seedlings, saplings and young shrubs were significantly greater (P < 0.05) in the ranch than the game reserve and communal area. The mature trees had a significantly greater density (P < 0.05) in the game reserve than the ranch and communal area. Soil analysis results showed that Magnesium (Mg), Potassium (K), Manganese (Mn) and Copper (Cu) had similar (P > 0.05) concentrations in soils obtained from all land management systems in both seasons. Soil Calcium (Ca) levels showed differences between land management systems in winter only being greater (P < 0.001) in the game reserve than the ranch and the communal lands. Soil Phosphorus (P) and Iron (Fe) also showed variations between land management systems in winter being significantly greater (P < 0.001) in the ranch than the other land management systems. The concentration of soil K differed between the two seasons in soils collected from the ranch and the communal lands, being greater (P < 0.001) in winter than summer seasons. Soil Zinc (Zn) also showed differences between land management systems in summer being greater (P < 0.001) in the game reserve than in the ranch and communal land. Seasonal variations were observed in soil P level of samples collected from the ranch being greater (P < 0.001) in winter than summer season. The concentration of soil Zn was higher (P < 0.001) in the soil collected from the game reserve and the ranch in summer than winter season. Woody forage analysis results showed that browse samples harvested from the ranch had greater (P < 0.001) Nitrogen (N) level than the other land management systems in both seasons. The browse samples harvested from the game reserve had greater (P < 0.001) Ca level than the other land management systems in winter season only. The level of P showed variations (P < 0.05) between land management systems in samples harvested during winter only being greater (P < 0.001) in samples from the ranch than the other land management systems. Similarly, browse harvested during winter showed significant differences (P < 0.05) in K levels being lowest in samples collected from game reserves, where the Ca level was greatest. Browse samples collected from the communal land and the ranch had the lowest Mg levels in summer and winter seasons, respectively. In all management systems, browse harvested during summer had greater (P < 0.001) N and P levels than those harvested in winter, and the reverse holds true for K and Ca levels. Browse samples harvested during winter had greater (P < 0.001) Mn levels in samples from the communal area and game reserve than the ranch, but in summer, the game reserve had higher Mn level than the other two sites. Browse samples harvested during winter only showed differences (P < 0.05) in Cu and Zn levels being greatest (P < 0.001) in samples collected from ranch and game reserves. In all management systems, browse samples harvested during winter had greater (P < 0.001) Fe, Mn, Zn and Cu (except for the game reserve and communal land) levels than those harvested in summer. Herbaceous analysis results showed that samples harvested in summer from the game reserve and ranch had greater (P < 0.001) TOC levels than the communal area, but in winter, samples from the game reserve and ranch had similar TOC levels, except for communal areas that had no herbaceous vegetation. Herbaceous samples harvested in winter from the ranch had greater (P < 0.001) TN levels than the game reserve, and that made the C:N ratio higher (P < 0.001) in the game reserve. Woody foliar samples harvested in winter from the game reserve and communal lands had greater (P < 0.001) TOC than the ranch. Values on C:N ratio showed that in winter, the communal and ranch had greater (P < 0.001) C:N than the game reserve, but in summer, the ranch had higher (P < 0.001) C:N than the game reserve and communal area. The vegetation TOC (kg ha-1) showed the order of the game reserve > ranch > communal area and the trend was similar in both seasons. In summer, the game reserve had the greatest (P < 0.001) TN (kg ha-1) followed by the ranch and the lowest in the communal area, but in winter the game reserve and ranch had similar and higher (P < 0.001) TN (kg ha-1) than the communal areas. In summer, both the game reserve and ranch recorded greater (P < 0.001) herbaceous δ13C and lowest δ15N than the communal area, but in winter, the game reserve had higher (P < 0.001) δ13C than the ranch, though both the game reserve and ranch had similar (P > 0.001) δ15N values. In summer, both the communal and ranch had slightly higher (P < 0.001) woody foliar δ13C than the game reserve, but in winter the ranch had greater (P < 0.001) δ13C than game reserve and communal areas. Woody foliar samples harvested from the ranch showed variations (P < 0.05) in δ15N between seasons being higher (P < 0.001) in summer than winter. The TOC was greatest in summer, in soils collected from the game reserve followed by the ranch and least in the communal land, but in winter, the lowest TOC was recorded in soils collected from the ranch. The soil C:N ratio varied between land management systems in soils collected during summer only being greater (P < 0.001) in the game and ranch than the communal area. The soil TOC (kg ha-1) and TN (kg ha-1) did not show (P > 0.05) differences between land management systems. Soil δ13C level was remarkably (P < 0.05) affected by land management systems, but did not interact with seasons. In both seasons, the communal land had slightly higher (P < 0.001) δ13C level than the other two land management systems. In both seasons, δ15N levels showed great differences (P < 0.001) between land management systems, with highest soil δ15N levels observed in the communal area than the ranch and game reserve. Results on social survey showed that the majority of the interviewed households in Omaandi (63percent), Oshitutuma (53percent) and Epukunoyana (50percent) were female headed families and the remaining were male headed. The mean population of goats and cattle were significantly higher (P < 0.05) in Omaandi and Epukunoyana than in Oshitutuma village, respectively. In this study, household respondents in all villages indicated that all livestock species were primarily kept for wealth status and provision of meat for consumption. Respondents in all villages also indicated that lack of grazing lands and shortage of feed were the primary constraints of livestock production followed by water scarcity and recurring droughts. Elder respondents in all villages perceived overgrazing and climate change as the primary cause of rangeland degradation. Elder interviewees in Omaandi and Oshitutuma villages regarded low grass cover and dominance of poor quality grass (Epukunoyana only) as the primary vegetation indicators of rangeland degradation. The animal related indicators such as stunted animal body as a result of mineral deficiency, high livestock mortality, emaciated body and animals traveling long distance for grazing and water (Oshitutuma only) were regarded in all villages as the primary livestock related indicators of rangeland degradation. Elders from Epukunoyana village ranked low rainfall, high soil and atmospheric temperatures as the primary climate related indicators of rangeland degradation, although in Omaandi and Oshitutuma, high soil and atmospheric temperatures were considered as the primary climate related indicators of rangeland degradation. Based on the findings, this study concludes that land management systems had great influences on the distribution and production of herbaceous and woody vegetation in summer and winter seasons. This study also observed that land management systems interacted strongly with season to influence most vegetation and soil variables. Lastly, based on the study findings, the study concludes that all three communal rangelands are degraded and degradation led to a gradual declining trend in the livestock population over the past 10 to 20 years in the communal areas as a result of feed shortage.
- Full Text:
- Date Issued: 2018
- Authors: Kahumba, Absalom
- Date: 2018
- Subjects: Rural development Land use Land tenure
- Language: English
- Type: Thesis , Doctoral , Pasture Science
- Identifier: http://hdl.handle.net/10353/11718 , vital:39100
- Description: This study was conducted in Ogongo district, situated in Omusati Region of the central northern Namibia. The objectives of this study were to assess the impact of land use practices on 1) vegetation distribution and status; 2) soil properties; 3) carbon-nitrogen sequestration potential, and 4) investigate the indigenous pastoralists’ knowledge and perceptions on livestock production, rangeland degradation and its indicators in three villages (Omaandi, Epukunoyana and Oshitutuma) in Mopane savannah rangelands of central northern Namibia. For vegetation and soil assessment, three grazing land management systems (communal, game reserve and cattle ranch) were identified adjacent to each other. In each grazing system, three sites (for game reserve and cattle ranch, these were camps) were selected. In each site, three belt transects of 50 m x 5 m2 were marked to record vegetation and soil data as well as to collect vegetation samples for analysis. Grass species composition was recorded using step point methods from 250 points per belt transect. A total of five 0.25 m2 quadrats were randomly laid within each 250 m2 belt transect to record the herbaceous plant density, tuft diameter, tuft distance and biomass. All woody plants in the belt transect (250 m2) were measured and recorded for species plant height and canopy diameters. Three soil samples per belt transect were collected at the time of forage sampling down to a depth of 20 cm using a soil auger. Soil and plant samples were analysed for macro and micro minerals, total organic carbon, total nitrogen, carbon-nitrogen ratios, and carbon and nitrogen isotopes. For bulk density, soil samples were collected using soil core samplers. In the social study, a total of 90 households were randomly selected from three villages and a total of 48 elders were purposefully selected based on the age, time spent in the village and livestock ownership. A combination of structured and semi-structured questionnaires were used to gather household information, while a structured questionnaire and open ended discussion were used to interview elders on the constraints of livestock production, rangeland degradation related issues and their consequences on livelihood. Field vegetation and soil data were analyzed using a General Linear Model (GLM) in SAS (2007), whereas the social data were analyzed using SPSS version 21 (2014). A total of 23 grass species were identified in all three land management systems, of which 48% were perennials and the remaining 52% were annuals. Aristida meridionalis dominated the game reserve and the ranch, whereas Eragrostis trichophora was dominant in all land management systems. Forbs occurred commonly in the game reserve and the ranch, but were dominant in the communal areas. The abundance of A. meridionalis responded significantly (P < 0.001) to land management systems with the game reserve showing remarkably greater abundance than the ranch. In summer, the abundance of E. trichophora was high (P < 0.001) in the game reserve followed by the communal and ranch sites, whereas in winter, the species had still greater abundance in the game reserve followed by the ranch. In summer, the mean grass density was greatest (P < 0.001) in the game reserve and least in the communal lands, but vice versa for the tuft distance. In summer, the average distance between tufts showed great variations (P < 0.001) with the communal areas having greater values than the ranch and game reserve. In winter, both the game reserve and the ranch showed records of similar grass tuft density and distance between tufts, whereas these values were nil for communal areas, because, there were no grasses recorded. Herbaceous plant dry matter was significantly greater (P < 0.05) in the game reserve followed by the ranch and the least in the communal areas. Results on biomass showed remarkably higher values (P < 0.001) in summer than winter in all land management systems. The total woody plant density was significantly higher (P < 0.001) in the ranch (542 TE ha-1) than the game reserve (449 TE ha-1) and communal area (324 TE ha-1). However, percentage of canopy cover did not differ significantly (P > 0.05) between the three land management systems. Woody plant density of height classes were significantly different (P < 0.05) between three land management systems. The abundance of seedlings, saplings and young shrubs were significantly greater (P < 0.05) in the ranch than the game reserve and communal area. The mature trees had a significantly greater density (P < 0.05) in the game reserve than the ranch and communal area. Soil analysis results showed that Magnesium (Mg), Potassium (K), Manganese (Mn) and Copper (Cu) had similar (P > 0.05) concentrations in soils obtained from all land management systems in both seasons. Soil Calcium (Ca) levels showed differences between land management systems in winter only being greater (P < 0.001) in the game reserve than the ranch and the communal lands. Soil Phosphorus (P) and Iron (Fe) also showed variations between land management systems in winter being significantly greater (P < 0.001) in the ranch than the other land management systems. The concentration of soil K differed between the two seasons in soils collected from the ranch and the communal lands, being greater (P < 0.001) in winter than summer seasons. Soil Zinc (Zn) also showed differences between land management systems in summer being greater (P < 0.001) in the game reserve than in the ranch and communal land. Seasonal variations were observed in soil P level of samples collected from the ranch being greater (P < 0.001) in winter than summer season. The concentration of soil Zn was higher (P < 0.001) in the soil collected from the game reserve and the ranch in summer than winter season. Woody forage analysis results showed that browse samples harvested from the ranch had greater (P < 0.001) Nitrogen (N) level than the other land management systems in both seasons. The browse samples harvested from the game reserve had greater (P < 0.001) Ca level than the other land management systems in winter season only. The level of P showed variations (P < 0.05) between land management systems in samples harvested during winter only being greater (P < 0.001) in samples from the ranch than the other land management systems. Similarly, browse harvested during winter showed significant differences (P < 0.05) in K levels being lowest in samples collected from game reserves, where the Ca level was greatest. Browse samples collected from the communal land and the ranch had the lowest Mg levels in summer and winter seasons, respectively. In all management systems, browse harvested during summer had greater (P < 0.001) N and P levels than those harvested in winter, and the reverse holds true for K and Ca levels. Browse samples harvested during winter had greater (P < 0.001) Mn levels in samples from the communal area and game reserve than the ranch, but in summer, the game reserve had higher Mn level than the other two sites. Browse samples harvested during winter only showed differences (P < 0.05) in Cu and Zn levels being greatest (P < 0.001) in samples collected from ranch and game reserves. In all management systems, browse samples harvested during winter had greater (P < 0.001) Fe, Mn, Zn and Cu (except for the game reserve and communal land) levels than those harvested in summer. Herbaceous analysis results showed that samples harvested in summer from the game reserve and ranch had greater (P < 0.001) TOC levels than the communal area, but in winter, samples from the game reserve and ranch had similar TOC levels, except for communal areas that had no herbaceous vegetation. Herbaceous samples harvested in winter from the ranch had greater (P < 0.001) TN levels than the game reserve, and that made the C:N ratio higher (P < 0.001) in the game reserve. Woody foliar samples harvested in winter from the game reserve and communal lands had greater (P < 0.001) TOC than the ranch. Values on C:N ratio showed that in winter, the communal and ranch had greater (P < 0.001) C:N than the game reserve, but in summer, the ranch had higher (P < 0.001) C:N than the game reserve and communal area. The vegetation TOC (kg ha-1) showed the order of the game reserve > ranch > communal area and the trend was similar in both seasons. In summer, the game reserve had the greatest (P < 0.001) TN (kg ha-1) followed by the ranch and the lowest in the communal area, but in winter the game reserve and ranch had similar and higher (P < 0.001) TN (kg ha-1) than the communal areas. In summer, both the game reserve and ranch recorded greater (P < 0.001) herbaceous δ13C and lowest δ15N than the communal area, but in winter, the game reserve had higher (P < 0.001) δ13C than the ranch, though both the game reserve and ranch had similar (P > 0.001) δ15N values. In summer, both the communal and ranch had slightly higher (P < 0.001) woody foliar δ13C than the game reserve, but in winter the ranch had greater (P < 0.001) δ13C than game reserve and communal areas. Woody foliar samples harvested from the ranch showed variations (P < 0.05) in δ15N between seasons being higher (P < 0.001) in summer than winter. The TOC was greatest in summer, in soils collected from the game reserve followed by the ranch and least in the communal land, but in winter, the lowest TOC was recorded in soils collected from the ranch. The soil C:N ratio varied between land management systems in soils collected during summer only being greater (P < 0.001) in the game and ranch than the communal area. The soil TOC (kg ha-1) and TN (kg ha-1) did not show (P > 0.05) differences between land management systems. Soil δ13C level was remarkably (P < 0.05) affected by land management systems, but did not interact with seasons. In both seasons, the communal land had slightly higher (P < 0.001) δ13C level than the other two land management systems. In both seasons, δ15N levels showed great differences (P < 0.001) between land management systems, with highest soil δ15N levels observed in the communal area than the ranch and game reserve. Results on social survey showed that the majority of the interviewed households in Omaandi (63percent), Oshitutuma (53percent) and Epukunoyana (50percent) were female headed families and the remaining were male headed. The mean population of goats and cattle were significantly higher (P < 0.05) in Omaandi and Epukunoyana than in Oshitutuma village, respectively. In this study, household respondents in all villages indicated that all livestock species were primarily kept for wealth status and provision of meat for consumption. Respondents in all villages also indicated that lack of grazing lands and shortage of feed were the primary constraints of livestock production followed by water scarcity and recurring droughts. Elder respondents in all villages perceived overgrazing and climate change as the primary cause of rangeland degradation. Elder interviewees in Omaandi and Oshitutuma villages regarded low grass cover and dominance of poor quality grass (Epukunoyana only) as the primary vegetation indicators of rangeland degradation. The animal related indicators such as stunted animal body as a result of mineral deficiency, high livestock mortality, emaciated body and animals traveling long distance for grazing and water (Oshitutuma only) were regarded in all villages as the primary livestock related indicators of rangeland degradation. Elders from Epukunoyana village ranked low rainfall, high soil and atmospheric temperatures as the primary climate related indicators of rangeland degradation, although in Omaandi and Oshitutuma, high soil and atmospheric temperatures were considered as the primary climate related indicators of rangeland degradation. Based on the findings, this study concludes that land management systems had great influences on the distribution and production of herbaceous and woody vegetation in summer and winter seasons. This study also observed that land management systems interacted strongly with season to influence most vegetation and soil variables. Lastly, based on the study findings, the study concludes that all three communal rangelands are degraded and degradation led to a gradual declining trend in the livestock population over the past 10 to 20 years in the communal areas as a result of feed shortage.
- Full Text:
- Date Issued: 2018
Understanding the reading practices of Fort Hare students
- Authors: O’Shea, Cathy
- Date: 2017
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/6886 , vital:21197
- Description: Universities world-wide are battling to offer access to far greater numbers than ever before. The University of Fort Hare, specifically, is also part of a troubled South African education system and is located in a disadvantaged, rural area. The main aim of this study was to understand Fort Hare students’ reading practices, as reported by the students themselves. This thesis used a framework of New Literacy Studies, which views student learning as a process of mastering discipline-specific, socially constructed norms and values, and sees the adopting of a literacy as including the adoption of an identity. Since discourse, in the NLS tradition, has been found to be a mediating mechanism in the social construction of identity, a critical discourse analysis was adopted to begin understanding aspects of Fort Hare students’ reading practices and the links between these and their identities. Critical realism is the ontological underpinning of this thesis. This means that the study aimed to identify the tendencies of certain mechanisms - in this case, Discourses - to affect students’ reading practices, by analysing interview transcripts of focus group discussions held with 30 students. Frameworks and tools provided by Fairclough and Gee were applied to interview data analysis. The ‘We blacks’ Discourse was one of one of the prominent Discourses that interviewees drew on when talking about their reading practices. It was closely allied to the ‘Resistance to reading’ Discourse, as participants explained that they tended to disregard books and did not enjoy reading for leisure. The ‘We blacks’ Discourse in this way homogenised class and other differences between black students, and indicated the ways in which their experiences were outside of academic Discourses. This Discourse served as a constraining mechanism for some, and indicated that those who used it tended not to identify with the academy. There was an evident link between the ‘We blacks’ Discourse, the ‘Resistance to reading’ Discourse and the ‘Better than us’ Discourse, in which students who enjoyed reading were called names for supposedly being conceited. Two opposing discourses (with a small ‘d’) emerged when students talked about literacy sponsors like parents and lecturers. Some used the ‘Our parents don’t chase us’ discourse to depict family members who were not encouraging, overlapping with the ‘We blacks’ Discourse. The contrasting ‘Go read anything’ discourse described more encouraging teachers and relatives. This discourse was also used to describe educators who had forced them to read, with several interviewees describing corporal punishment as being a necessary part of school-based literacy practices. It also became clear that Fort Hare’s institutional identity played a role in some interviewees’ self-identities, as the ‘Resistance to reading’ Discourse was linked to the ‘Why bother?’ Discourse. The latter seemed part of a defensive positionality that arose partly because some students see Fort Hare as a university with relatively low academic standards. However, the implication is that lecturers and others can work towards changing Discourses and so endeavour to enable reading practices. Educators could also take steps to address resistant attitudes and encourage reading.
- Full Text:
- Date Issued: 2017
- Authors: O’Shea, Cathy
- Date: 2017
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/6886 , vital:21197
- Description: Universities world-wide are battling to offer access to far greater numbers than ever before. The University of Fort Hare, specifically, is also part of a troubled South African education system and is located in a disadvantaged, rural area. The main aim of this study was to understand Fort Hare students’ reading practices, as reported by the students themselves. This thesis used a framework of New Literacy Studies, which views student learning as a process of mastering discipline-specific, socially constructed norms and values, and sees the adopting of a literacy as including the adoption of an identity. Since discourse, in the NLS tradition, has been found to be a mediating mechanism in the social construction of identity, a critical discourse analysis was adopted to begin understanding aspects of Fort Hare students’ reading practices and the links between these and their identities. Critical realism is the ontological underpinning of this thesis. This means that the study aimed to identify the tendencies of certain mechanisms - in this case, Discourses - to affect students’ reading practices, by analysing interview transcripts of focus group discussions held with 30 students. Frameworks and tools provided by Fairclough and Gee were applied to interview data analysis. The ‘We blacks’ Discourse was one of one of the prominent Discourses that interviewees drew on when talking about their reading practices. It was closely allied to the ‘Resistance to reading’ Discourse, as participants explained that they tended to disregard books and did not enjoy reading for leisure. The ‘We blacks’ Discourse in this way homogenised class and other differences between black students, and indicated the ways in which their experiences were outside of academic Discourses. This Discourse served as a constraining mechanism for some, and indicated that those who used it tended not to identify with the academy. There was an evident link between the ‘We blacks’ Discourse, the ‘Resistance to reading’ Discourse and the ‘Better than us’ Discourse, in which students who enjoyed reading were called names for supposedly being conceited. Two opposing discourses (with a small ‘d’) emerged when students talked about literacy sponsors like parents and lecturers. Some used the ‘Our parents don’t chase us’ discourse to depict family members who were not encouraging, overlapping with the ‘We blacks’ Discourse. The contrasting ‘Go read anything’ discourse described more encouraging teachers and relatives. This discourse was also used to describe educators who had forced them to read, with several interviewees describing corporal punishment as being a necessary part of school-based literacy practices. It also became clear that Fort Hare’s institutional identity played a role in some interviewees’ self-identities, as the ‘Resistance to reading’ Discourse was linked to the ‘Why bother?’ Discourse. The latter seemed part of a defensive positionality that arose partly because some students see Fort Hare as a university with relatively low academic standards. However, the implication is that lecturers and others can work towards changing Discourses and so endeavour to enable reading practices. Educators could also take steps to address resistant attitudes and encourage reading.
- Full Text:
- Date Issued: 2017
Phylogenetics of the keratin-feeding beetle family Trogidae (Coleoptera: Scarabaeoidea)
- Authors: Strümpher, Werner Petrus
- Date: 2016
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/1232 , vital:20037
- Description: Trogidae constitute a monophyletic and biologically unique family within the Scarabaeoidea, being the only keratinophagous group in its superfamily. Traditionally, the family has been divided into three distinctive genera, Omorgus Erichson, Polynoncus Burmeister, and Trox Fabricius. Although the taxonomy of the group is relatively well studied, recently changes to the existing classification have been proposed without the family as currently constituted being subjected to phylogenetic analyses. In this study I present the first molecular phylogeny for this cosmopolitan family, based on three partially sequenced gene regions: 16SrRNA, 18S rRNA and 28S rRNA domain 2. Analyses resolved relationships between and within genera and subgenera that are largely congruent with existing taxonomic hypotheses based on morphology. I recovered four well-supported radiations: Polynoncus, Omorgus, Holarctic Trox and Afrotropical Phoberus. One of the more surprising results was the monophyly of Phoberus. Based on the evidence, I propose reinstating the genus Phoberus to accommodate all Afrotropical (including Madagascan endemic) species. The results re-emphasise the validity of Scholtz’s (1986a) classification system for the genus Omorgusand its subgeneraand provide evidence of an African origin for Madagascan trogids. Divergence analysis was able to date the major events for the origin of extant lineages of Trogidae. The subsequent diversification of the major lineages is largely attributed to Pangaean and Gondwanan vicariance events in the Mid-Jurassic and early Late Cretaceous, respectively. The separation of the landmasses resulted in the evolution of four distinct groups: Omorgus, Polynoncus, Trox and Phoberus. The monophyletic subgenus Phoberus MacLeay is of particular interest; about one-third (14 of 40) of the species in the Afrotropical region have lost the ability to fly. To gain insights into the evolution of flightlessness in this clade, phylogenetic relationships among species were inferred using molecular sequence data. Four partial sequences of four genes (COI, 16S, 18S and 28S domain 2) were obtained for 27 species, covering all of the recognised species-groups. Estimated times of divergence were based on published mutation rates for COI. The results recovered eight monophyletic lineages, supporting the morphology-based subdivisions of the genus. Flightlessness evolved at least five times within the subgenus. There is no strong support for the re-acquisition of functional wings once they are lost. Diversification, and the present relictual distributions, in African Phoberus can be linked to climatic and geological events associated with the Miocene and Pliocene Climate Optimum in southern Africa. The evolution of flightlessness in Phoberus is consistent with the habitat stability hypothesis. All flightless species occupy refugial areas with relatively long-term environmental stability. Phoberus is a promising model group for studying evolutionary trends relating to flightlessness, speciation and biogeography. Flightlessness is a counterintuitive evolutionary development, given the many advantages of flight. To interpret the diversification in the flightless Phoberus capensis Scholtz, the phylogenetic relationships among several populations of P. capensis are investigated. Phylogenetic relationships among populations were inferred using molecular sequence data that suggested three distinct evolutionary lineages, which was also supported by morphological characters. Divergence time estimates suggest a Pliocene-Pleistocene diversification. Based on these results, it is suggested that P. capensis experienced climatically-driven allopatric speciation with sheltered Afrotemperate forests and high mountain peaks serving as important refugia in response to climatic exacerbations. The P. capensis complex thus represents a speciation process in which flight-restricted populations evolved in close allopatry, possibly as recently as the Pleistocene. Two of the three divergent and geographically distinct lineages are described as novel species. This study represents the most recent comprehensive work on the Trogidae. On the basis of this study, it is proposed that taxonomic changes to the generic classification of the family be made. Trogidae are formally divided into two subfamilies, Omorginae and Troginae. The subgenus Phoberus is restored to genus rank to include all the Afrotropical species, and Afromorgus is confirmed at subgeneric rank. The genus Madagatrox is synonymised with Phoberus.
- Full Text:
- Date Issued: 2016
- Authors: Strümpher, Werner Petrus
- Date: 2016
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/1232 , vital:20037
- Description: Trogidae constitute a monophyletic and biologically unique family within the Scarabaeoidea, being the only keratinophagous group in its superfamily. Traditionally, the family has been divided into three distinctive genera, Omorgus Erichson, Polynoncus Burmeister, and Trox Fabricius. Although the taxonomy of the group is relatively well studied, recently changes to the existing classification have been proposed without the family as currently constituted being subjected to phylogenetic analyses. In this study I present the first molecular phylogeny for this cosmopolitan family, based on three partially sequenced gene regions: 16SrRNA, 18S rRNA and 28S rRNA domain 2. Analyses resolved relationships between and within genera and subgenera that are largely congruent with existing taxonomic hypotheses based on morphology. I recovered four well-supported radiations: Polynoncus, Omorgus, Holarctic Trox and Afrotropical Phoberus. One of the more surprising results was the monophyly of Phoberus. Based on the evidence, I propose reinstating the genus Phoberus to accommodate all Afrotropical (including Madagascan endemic) species. The results re-emphasise the validity of Scholtz’s (1986a) classification system for the genus Omorgusand its subgeneraand provide evidence of an African origin for Madagascan trogids. Divergence analysis was able to date the major events for the origin of extant lineages of Trogidae. The subsequent diversification of the major lineages is largely attributed to Pangaean and Gondwanan vicariance events in the Mid-Jurassic and early Late Cretaceous, respectively. The separation of the landmasses resulted in the evolution of four distinct groups: Omorgus, Polynoncus, Trox and Phoberus. The monophyletic subgenus Phoberus MacLeay is of particular interest; about one-third (14 of 40) of the species in the Afrotropical region have lost the ability to fly. To gain insights into the evolution of flightlessness in this clade, phylogenetic relationships among species were inferred using molecular sequence data. Four partial sequences of four genes (COI, 16S, 18S and 28S domain 2) were obtained for 27 species, covering all of the recognised species-groups. Estimated times of divergence were based on published mutation rates for COI. The results recovered eight monophyletic lineages, supporting the morphology-based subdivisions of the genus. Flightlessness evolved at least five times within the subgenus. There is no strong support for the re-acquisition of functional wings once they are lost. Diversification, and the present relictual distributions, in African Phoberus can be linked to climatic and geological events associated with the Miocene and Pliocene Climate Optimum in southern Africa. The evolution of flightlessness in Phoberus is consistent with the habitat stability hypothesis. All flightless species occupy refugial areas with relatively long-term environmental stability. Phoberus is a promising model group for studying evolutionary trends relating to flightlessness, speciation and biogeography. Flightlessness is a counterintuitive evolutionary development, given the many advantages of flight. To interpret the diversification in the flightless Phoberus capensis Scholtz, the phylogenetic relationships among several populations of P. capensis are investigated. Phylogenetic relationships among populations were inferred using molecular sequence data that suggested three distinct evolutionary lineages, which was also supported by morphological characters. Divergence time estimates suggest a Pliocene-Pleistocene diversification. Based on these results, it is suggested that P. capensis experienced climatically-driven allopatric speciation with sheltered Afrotemperate forests and high mountain peaks serving as important refugia in response to climatic exacerbations. The P. capensis complex thus represents a speciation process in which flight-restricted populations evolved in close allopatry, possibly as recently as the Pleistocene. Two of the three divergent and geographically distinct lineages are described as novel species. This study represents the most recent comprehensive work on the Trogidae. On the basis of this study, it is proposed that taxonomic changes to the generic classification of the family be made. Trogidae are formally divided into two subfamilies, Omorginae and Troginae. The subgenus Phoberus is restored to genus rank to include all the Afrotropical species, and Afromorgus is confirmed at subgeneric rank. The genus Madagatrox is synonymised with Phoberus.
- Full Text:
- Date Issued: 2016
Effect of post-slaughter handling on physico-chemical and microbiological quality of red meat along the distribution chain in the Eastern Cape Province, South Africa
- Authors: Rani, Zikhona Theodora
- Date: 2015
- Subjects: Meat -- Microbiology Meat -- Transportation -- South Africa -- Eastern Cape Meat -- Quality -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10353/2490 , vital:27875
- Description: The broad objective of the study was to investigate the effect of post-slaughter handling in the distribution chain on red meat quality and safety. A survey was conducted among 300 consumers and 100 meat handlers in five different municipalities (Buffalo City, Nkonkobe, Ngqushwa, Lukhanje and Amahlathi) in the Eastern Cape Province of South Africa to investigate their perceptions on meat quality and safety, together with challenges faced by meat handlers during the distribution of meat from the abattoir to retailers. The microbiological profile and physico-chemical quality of red meat at different stages of the abattoir to retail outlets in the distribution chain were also determined. Swabs (n=216) and meat samples (n=450) were collected from beef, pork and mutton carcasses during the loading process of carcasses into trucks at the abattoir, when offloading carcasses at the supply points and during marketing. Physico-chemical qualities such as colour (L* - lightness, b* - redness and a* - yellowness) and meat pH measurements were taken at each point. To determine the microbiological profiles of the carcasses, four microbiological parameters were considered: Total bacteria count (general bacteria), coliform count (related to hygiene and indicator for pathogens), Escherichia coli (Gram-negative pathogen) and Staphylococcus aureus (Gram-positive pathogen). Two types of packaging (vacuum and overwrapping) were used to determine their effect on shelf-life and microbiological quality of red meat under the normal marketing conditions over a storage duration of 15 days. The results from the study showed low awareness of consumers about the pathogenic diseases which arise from meat. A strong significant association (p ˂ 0.05) between educational status and awareness on meat safety was observed. Most of the consumers perceived that quality goes beyond safety such that 35.6 percent of the respondents indicated that they did not have a problem with consuming spoiled meat, whilst the remaining 64.4 percent indicated that they would r eject spoiled meat. Although retailers indicated that they take meat safety into consideration in their shops, 92 percent of the retailers revealed that they do not perform microbial assessment of meat in their shops. A series of loading and off-loading, temperature fluctuations, environmental temperatures and ques during offloading were reported as the major challenges during transportation of carcasses from the abattoir to the supply points. The microbial counts were significantly (p<0.05) higher in samples from the commercial abattoir than in those from the communal abattoir. Escherichia coli was the predominant microbial contaminant in the samples from both abattoirs. When following the chain, total bacterial count (TBC), coliform count (CC) and the levels of E. coli contamination increased progressively between the loading and the off-loading points (5.1 to 7.9 log10 CFU/cm2; 5.0 to 5.6 log10 CFU/cm2 and 2.7 to 3.7 log10 CFU/cm2, respectively). The storage period, meat type, distance during transportation and temperature were found to have a significant impact on the microbial levels during the distribution of carcasses. Distribution stage had a significant effect (p<0.05) on some of the physico- chemical meat quality attributes and differences in the lightness (L*) and redness (a*) values between the loading, off-loading and display points were observed. Consumers perceived retailer class as one of the factors influencing meat quality, but according to the instrumental measurements retailer class did not have a significant effect on physico-chemical meat quality. However, distance and storage duration significantly (p<0.05) affected (L*) and (a*) values in the meat during distribution chain. Vacuum and overwrapping packaging significantly affected (p<0.05) the shelf life of meat. Therefore, it was concluded that post-slaughter handling during the distribution chain affects the physico- chemical, microbiological and shelf-life of meat.
- Full Text:
- Date Issued: 2015
- Authors: Rani, Zikhona Theodora
- Date: 2015
- Subjects: Meat -- Microbiology Meat -- Transportation -- South Africa -- Eastern Cape Meat -- Quality -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10353/2490 , vital:27875
- Description: The broad objective of the study was to investigate the effect of post-slaughter handling in the distribution chain on red meat quality and safety. A survey was conducted among 300 consumers and 100 meat handlers in five different municipalities (Buffalo City, Nkonkobe, Ngqushwa, Lukhanje and Amahlathi) in the Eastern Cape Province of South Africa to investigate their perceptions on meat quality and safety, together with challenges faced by meat handlers during the distribution of meat from the abattoir to retailers. The microbiological profile and physico-chemical quality of red meat at different stages of the abattoir to retail outlets in the distribution chain were also determined. Swabs (n=216) and meat samples (n=450) were collected from beef, pork and mutton carcasses during the loading process of carcasses into trucks at the abattoir, when offloading carcasses at the supply points and during marketing. Physico-chemical qualities such as colour (L* - lightness, b* - redness and a* - yellowness) and meat pH measurements were taken at each point. To determine the microbiological profiles of the carcasses, four microbiological parameters were considered: Total bacteria count (general bacteria), coliform count (related to hygiene and indicator for pathogens), Escherichia coli (Gram-negative pathogen) and Staphylococcus aureus (Gram-positive pathogen). Two types of packaging (vacuum and overwrapping) were used to determine their effect on shelf-life and microbiological quality of red meat under the normal marketing conditions over a storage duration of 15 days. The results from the study showed low awareness of consumers about the pathogenic diseases which arise from meat. A strong significant association (p ˂ 0.05) between educational status and awareness on meat safety was observed. Most of the consumers perceived that quality goes beyond safety such that 35.6 percent of the respondents indicated that they did not have a problem with consuming spoiled meat, whilst the remaining 64.4 percent indicated that they would r eject spoiled meat. Although retailers indicated that they take meat safety into consideration in their shops, 92 percent of the retailers revealed that they do not perform microbial assessment of meat in their shops. A series of loading and off-loading, temperature fluctuations, environmental temperatures and ques during offloading were reported as the major challenges during transportation of carcasses from the abattoir to the supply points. The microbial counts were significantly (p<0.05) higher in samples from the commercial abattoir than in those from the communal abattoir. Escherichia coli was the predominant microbial contaminant in the samples from both abattoirs. When following the chain, total bacterial count (TBC), coliform count (CC) and the levels of E. coli contamination increased progressively between the loading and the off-loading points (5.1 to 7.9 log10 CFU/cm2; 5.0 to 5.6 log10 CFU/cm2 and 2.7 to 3.7 log10 CFU/cm2, respectively). The storage period, meat type, distance during transportation and temperature were found to have a significant impact on the microbial levels during the distribution of carcasses. Distribution stage had a significant effect (p<0.05) on some of the physico- chemical meat quality attributes and differences in the lightness (L*) and redness (a*) values between the loading, off-loading and display points were observed. Consumers perceived retailer class as one of the factors influencing meat quality, but according to the instrumental measurements retailer class did not have a significant effect on physico-chemical meat quality. However, distance and storage duration significantly (p<0.05) affected (L*) and (a*) values in the meat during distribution chain. Vacuum and overwrapping packaging significantly affected (p<0.05) the shelf life of meat. Therefore, it was concluded that post-slaughter handling during the distribution chain affects the physico- chemical, microbiological and shelf-life of meat.
- Full Text:
- Date Issued: 2015
Ecological consequences of non-native fish invasion in Eastern Cape headwater streams
- Authors: Ellender, Bruce Robert
- Date: 2014
- Subjects: Fishery management -- South Africa -- Eastern Cape Fishes -- Conservation -- South Africa Introduced fishes -- South Africa -- Eastern Cape Introduced organisms
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/69065 , vital:29380
- Description: The introduction, spread and concomitant impacts of non-native species are a global problem. Fish are among the most widely introduced vertebrate groups, with their impacts affecting multiple levels of organisation- from individuals, populations and communities, to entire ecosystems. In South Africa, the largest perceived threat to range-restricted endemic headwater stream fishes is said to be invasion by non-native fishes, however, as is the case elsewhere, invasive impacts are often a case of risk perception rather than actual risk analysis. Two range-restricted headwater species, the Eastern Cape redfin Pseudobarbus afer and the Border barb Barbus trevelyani are redlisted by the International Union for the Conservation of Nature (IUCN) as ‘Endangered’, primarily due to invasion by non-native fishes. To investigate invasions in South Africa, and provide a quantitative estimate of the impact of non-native fishes on the two imperilled endemics, P. afer and B. trevelyani, the overall aims of this thesis were to: (A) Provide a literature review on non-native fish invasions in South Africa; (B) Using two case studies on the headwaters of the perennial Keiskamma and episodic Swartkops River systems, investigate the naturalisation-invasion continuum to provide a holistic view of the invasion process in these variable environments. The specific thesis objectives were: (1) Reviewing current knowledge of invasive impacts of non-native fishes in South Africa; (2) Investigating invasibility of headwater stream environments by non-native fishes; (3) Determining the establishment success of non-native fishes, (4) Assessing the spatial and temporal impacts of invasion; (5) Understanding mechanisms responsible for non-native fish impacts; (6) Investigating the threat of non-native fish invasion on the genetic diversity of two the two headwater fishes, P. afer and B. trevelyani. Results from the literature review of fish invasions (Chapter 1) showed that South Africa has a long history of non-native fish introductions, spanning two and a half centuries. Currently, 55 species have been introduced or translocated. Many of these introduced species have become fully invasive (36%). Their impacts also span multiple levels of biological organisation. There was a general paucity of studies on fish invasions (38 studies), however, of those conducted, reviewed studies placed emphases on invasive impacts (25 studies) and the transport, introduction, establishment and spread stages of the invasion process were largely ignored. The two study systems, the Swartkops and Keiskamma Rivers, were heavily invaded and numbers of introduced species surpassed that of natives (Chapter 2, 3 and 5). Headwater streams had varying invasibility and a number of non-native species were successfully established (Chapter 2, 3, 5 and 6). The remainder of the invasions were casual incursions into headwater streams from source populations in mainstream and impoundment environments which were invasion hotspots. Irrespective of establishment, four predatory invaders (largemouth bass Micropterus salmoides, smallmouth bass M. dolomieu, brown trout Salmo trutta and rainbow trout Oncorhynchus mykiss) impacted heavily on native fish communities (Chapter 3, 4 and 5). Two broad types of invasion were documented, top down invasion by non-native O. mykiss and S. trutta and upstream invasion by M. salmoides and M. dolomieu (Chapter 3 and 5). Their impacts included changes in community structure, extirpation from invaded stream reaches resulting in contracted distribution, and isolation and fragmentation of native fish populations. The impacts of non-native predatory fishes were particularly acute for P. afer and B. trevelyani. Where non-native predatory fish occurred, P. afer and B. trevelyani had been extirpated (Chapter 3 and 5). As a result both native species exhibited contracted distributions (>20% habitat loss due to invasion). Upstream invasion by centrarchids isolated and fragmented P. afer populations into headwater refugia, while top down invasion by salmonids excluded B. trevelyani from invaded, more pristine stream reaches, by forcing the species into degraded unsuitable lower stream reaches. Predation also disrupted population processes such as adult dispersal for P. afer, and centrarchid-invaded zones acted as demographic sinks, where adults dispersing through invaded reaches were rapidly depleted. While the Mandela lineage of P. afer exhibited little within or between drainage genetic structuring, B. trevelyani was >4% divergent between drainages, and up to 2% divergent between streams within the Keiskamma River system (Chapter 7). The distribution of genetic diversity for B. trevelyani also indicated that the loss of diversity was imminent without immediate conservation interventions. This thesis has provided conclusive evidence that native fishes are vulnerable to invasion and that non-native predatory fishes have significant impacts on native fishes in Eastern Cape headwater streams. If management and conservation measures are implemented, the unwanted introduction and spread of non-native fishes may be restricted, allowing native fishes opportunities for recovery.
- Full Text:
- Date Issued: 2014
- Authors: Ellender, Bruce Robert
- Date: 2014
- Subjects: Fishery management -- South Africa -- Eastern Cape Fishes -- Conservation -- South Africa Introduced fishes -- South Africa -- Eastern Cape Introduced organisms
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/69065 , vital:29380
- Description: The introduction, spread and concomitant impacts of non-native species are a global problem. Fish are among the most widely introduced vertebrate groups, with their impacts affecting multiple levels of organisation- from individuals, populations and communities, to entire ecosystems. In South Africa, the largest perceived threat to range-restricted endemic headwater stream fishes is said to be invasion by non-native fishes, however, as is the case elsewhere, invasive impacts are often a case of risk perception rather than actual risk analysis. Two range-restricted headwater species, the Eastern Cape redfin Pseudobarbus afer and the Border barb Barbus trevelyani are redlisted by the International Union for the Conservation of Nature (IUCN) as ‘Endangered’, primarily due to invasion by non-native fishes. To investigate invasions in South Africa, and provide a quantitative estimate of the impact of non-native fishes on the two imperilled endemics, P. afer and B. trevelyani, the overall aims of this thesis were to: (A) Provide a literature review on non-native fish invasions in South Africa; (B) Using two case studies on the headwaters of the perennial Keiskamma and episodic Swartkops River systems, investigate the naturalisation-invasion continuum to provide a holistic view of the invasion process in these variable environments. The specific thesis objectives were: (1) Reviewing current knowledge of invasive impacts of non-native fishes in South Africa; (2) Investigating invasibility of headwater stream environments by non-native fishes; (3) Determining the establishment success of non-native fishes, (4) Assessing the spatial and temporal impacts of invasion; (5) Understanding mechanisms responsible for non-native fish impacts; (6) Investigating the threat of non-native fish invasion on the genetic diversity of two the two headwater fishes, P. afer and B. trevelyani. Results from the literature review of fish invasions (Chapter 1) showed that South Africa has a long history of non-native fish introductions, spanning two and a half centuries. Currently, 55 species have been introduced or translocated. Many of these introduced species have become fully invasive (36%). Their impacts also span multiple levels of biological organisation. There was a general paucity of studies on fish invasions (38 studies), however, of those conducted, reviewed studies placed emphases on invasive impacts (25 studies) and the transport, introduction, establishment and spread stages of the invasion process were largely ignored. The two study systems, the Swartkops and Keiskamma Rivers, were heavily invaded and numbers of introduced species surpassed that of natives (Chapter 2, 3 and 5). Headwater streams had varying invasibility and a number of non-native species were successfully established (Chapter 2, 3, 5 and 6). The remainder of the invasions were casual incursions into headwater streams from source populations in mainstream and impoundment environments which were invasion hotspots. Irrespective of establishment, four predatory invaders (largemouth bass Micropterus salmoides, smallmouth bass M. dolomieu, brown trout Salmo trutta and rainbow trout Oncorhynchus mykiss) impacted heavily on native fish communities (Chapter 3, 4 and 5). Two broad types of invasion were documented, top down invasion by non-native O. mykiss and S. trutta and upstream invasion by M. salmoides and M. dolomieu (Chapter 3 and 5). Their impacts included changes in community structure, extirpation from invaded stream reaches resulting in contracted distribution, and isolation and fragmentation of native fish populations. The impacts of non-native predatory fishes were particularly acute for P. afer and B. trevelyani. Where non-native predatory fish occurred, P. afer and B. trevelyani had been extirpated (Chapter 3 and 5). As a result both native species exhibited contracted distributions (>20% habitat loss due to invasion). Upstream invasion by centrarchids isolated and fragmented P. afer populations into headwater refugia, while top down invasion by salmonids excluded B. trevelyani from invaded, more pristine stream reaches, by forcing the species into degraded unsuitable lower stream reaches. Predation also disrupted population processes such as adult dispersal for P. afer, and centrarchid-invaded zones acted as demographic sinks, where adults dispersing through invaded reaches were rapidly depleted. While the Mandela lineage of P. afer exhibited little within or between drainage genetic structuring, B. trevelyani was >4% divergent between drainages, and up to 2% divergent between streams within the Keiskamma River system (Chapter 7). The distribution of genetic diversity for B. trevelyani also indicated that the loss of diversity was imminent without immediate conservation interventions. This thesis has provided conclusive evidence that native fishes are vulnerable to invasion and that non-native predatory fishes have significant impacts on native fishes in Eastern Cape headwater streams. If management and conservation measures are implemented, the unwanted introduction and spread of non-native fishes may be restricted, allowing native fishes opportunities for recovery.
- Full Text:
- Date Issued: 2014
Petrogenesis and metallogenesis of the Panzhihua Fe-Ti oxide ore-bearing mafic layered intrusion, SW China
- Authors: Howarth, Geoffrey Hamilton
- Date: 2013
- Subjects: Petrogenesis Metallogeny Intrusions (Geology) -- China -- Panzhihua Metallogenic provinces -- China -- Panzhihua Igneous rocks -- China -- Panzhihua Geochemistry Iron Titanium Oxides Ores Magmas
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4915 , http://hdl.handle.net/10962/d1001810
- Description: The Panzhihua intrusion is one of several large Fe-Ti oxide ore bearing intrusions related to the major flood volcanism of the Emeishan Large Igneous Province (ELIP), SW China. The Panzhihua intrusion in particular has recently become the focus of numerous studies owing to the excellent exposure in large open pit mining operations. The formation of Fe-Ti oxide ore layers has been the focus of these studies and has become a somewhat controversial topic with three separate models currently proposed for ore formation. The gabbroic Panzhihua intrusion extends for ± 19 km along strike, has a maximum thickness of 3000 m and hosts extensive (up to 60 m thick) Fe-Ti oxide ore layers in the lower portions of the intrusion. The intrusion has been divided into five zones: marginal zone (MGZ), lower zone (LZ), middle zone A (MZa), middle zone b (MZb) and the upper zone (UZ). The gabbroic rocks are comprised of plagioclase, clinopyroxene and interstitial Fe-Ti oxides with minor olivine. Apatite is present within the MZb only and shows no correlation with Fe-Ti oxide ore layers. Fe-Ti oxides are present throughout the stratigraphy of the intrusion. This is unlike typical layered intrusions where significant Fe-enrichment through fractionation of Fe-poor silicate phases (i.e. plagioclase) is required before Fe-Ti oxide saturation. There are no oxide-free cumulate rocks at the Panzhihua intrusion, implying either an evolved parent magma or very high Fe content of the source rocks. I present here new mineral composition data, whole-rock major and trace element geochemistry along with whole-rock Sr-Nd isotopes and PGEs in order to constrain the evolution of the Panzhihua parent magma en route from source to chamber and the formation of Fe-Ti oxide ore layers. Furthermore an initial pilot study using O-isotope data is conducted on Ti-magnetite and plagioclase separates from gabbroic vs. ore rocks. Results are coupled with detailed thermodynamic modeling using the software PELE in order to further constrain Fe-Ti oxide ore layer formation. The intrusion is characterised by extreme depletion of PGEs relative to the coeval flood basalts and picrites. High Cu/Pd and Pd/Pt imply two separate stages of S-saturated and S-undersaturated depletion of PGEs. Pd is highly compatible in sulphide and is quickly scavenged by sulphide liquids resulting in an increase in Cu/Pd of the residual liquid. Furthermore decoupling of Pd and Pt can be achieved by either late stage hydrothermal alteration or through S-undersaturated stage of PGE depletion where Pt is scavenged by Pt-rich alloys or oxide minerals. I show that the latter is more likely. Fractionation modeling suggests that the Panzhihua parent magma formed at depth from original picritic magma. This is consistent with several other recent studies on other layered intrusions of the ELIP. Sr-Nd isotopic ratios indicate very little crustal contamination has occurred en route to the current chamber. Sr and Nd concentrations of footwall rocks are too low to produce any significant change in initial Sr and Nd isotopic ratios of the intruding basaltic magmas, indicating that crustal contamination will not be indicated by Sr-Nd isotopic ratios. Gradational change in the Sr-Nd isotope ratios across the MGZ provides strong evidence for formation in an open system by multiple replenishments of progressively less contaminated magmas from depth. Contamination is difficult to constrain but must be occurring prior to emplacement at the current level (low Sr and Nd contents of footwall). A gradational upward decrease in highly incompatible element across the MGZ can then be explained by continuous magma flow, which effectively removes the evolved intercumulus liquids from the growing cumulate pile at the base of the chamber. The initial stages of formation of the Panzhihua intrusion are interpreted to result from prolonged low volume pulses of magma into a slowly opening chamber. The timing of Fe-Ti oxide crystallisation is fundamental in the understanding of the petrogenesis of ore layers. Distinct geochemical variation in whole-rock Fe2O3/TiO2 and Zr/Nb indicates that Timagnetite is the dominant oxide within the lower ± 270 m of the intrusion whereas above this level both Ti-magnetite and ilmenite are present as cumulus phases. This is interpreted to indicate a variation in the fO2 where the lower intrusion crystallises at higher fO2 relative to that above this level. Silicates within the ore layers, in particular plagioclase, are highly embayed and resorped where in contact with Fe-Ti oxides. This characteristic of the silicate grains implies early crystallisation prior to Fe-Ti oxides with subsequent disequilibrium conditions resulting in resorption. Furthermore distinct reaction rims of kaersutite amphibole, Fo-enriched olivine, An-enriched plagioclase and pleonaste are observed. The abundance of amphibole suggests H2O involvement in this reaction and consumption of silicates. A model for parent magma crystallisation at various H2O contents indicates that plagioclase crystallisation temperature is very sensitive to H2O content of the parent magma. Plagioclase crystallises early for “dry” compositions but significantly later for “wet” compositions. Fe-Ti oxide ore layers are generally well layered, contain gabbroic xenoliths and are observed raversing/cross-cutting the cumulate stratigraphy. I present here a new model for ore layer formation in order to account for these distinct features of the ore layers. A model invoking multiple replenishments of magma with variable oxide microphenocryst content, H2O content and volume is proposed. Magma evolving in the plumbing system and fed to the Panzhihua chamber is variably enriched in H2O, which results in significantly different crystallisation paths. High H2O magmas (> 2 wt %) crystallise Fe-Ti oxides early whereas low H2O magmas (< 1 wt %) crystallise oxides late. Early pulses of H2O-poor magma crystallise a sequence of plag+cpx+Fe-Ti oxide (±ol). Later pulses of H2Orich magma subsequently intrude the partially crystallised cumulate sequence incorporating and consuming previously crystallised silicates with subsequent early crystallisation of Ti-magnetite and formation of ore layers. H2O-rich magmas likely have suspended Ti-magnetite microphenocrysts as well, which crystallise at depth in the plumbing system. This model can account for the various characteristic features of the Fe-Ti oxide ore layers at the Panzhihua intrusion as well as other Fe-Ti oxide ore bearing intrusions in the region.
- Full Text:
- Date Issued: 2013
- Authors: Howarth, Geoffrey Hamilton
- Date: 2013
- Subjects: Petrogenesis Metallogeny Intrusions (Geology) -- China -- Panzhihua Metallogenic provinces -- China -- Panzhihua Igneous rocks -- China -- Panzhihua Geochemistry Iron Titanium Oxides Ores Magmas
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4915 , http://hdl.handle.net/10962/d1001810
- Description: The Panzhihua intrusion is one of several large Fe-Ti oxide ore bearing intrusions related to the major flood volcanism of the Emeishan Large Igneous Province (ELIP), SW China. The Panzhihua intrusion in particular has recently become the focus of numerous studies owing to the excellent exposure in large open pit mining operations. The formation of Fe-Ti oxide ore layers has been the focus of these studies and has become a somewhat controversial topic with three separate models currently proposed for ore formation. The gabbroic Panzhihua intrusion extends for ± 19 km along strike, has a maximum thickness of 3000 m and hosts extensive (up to 60 m thick) Fe-Ti oxide ore layers in the lower portions of the intrusion. The intrusion has been divided into five zones: marginal zone (MGZ), lower zone (LZ), middle zone A (MZa), middle zone b (MZb) and the upper zone (UZ). The gabbroic rocks are comprised of plagioclase, clinopyroxene and interstitial Fe-Ti oxides with minor olivine. Apatite is present within the MZb only and shows no correlation with Fe-Ti oxide ore layers. Fe-Ti oxides are present throughout the stratigraphy of the intrusion. This is unlike typical layered intrusions where significant Fe-enrichment through fractionation of Fe-poor silicate phases (i.e. plagioclase) is required before Fe-Ti oxide saturation. There are no oxide-free cumulate rocks at the Panzhihua intrusion, implying either an evolved parent magma or very high Fe content of the source rocks. I present here new mineral composition data, whole-rock major and trace element geochemistry along with whole-rock Sr-Nd isotopes and PGEs in order to constrain the evolution of the Panzhihua parent magma en route from source to chamber and the formation of Fe-Ti oxide ore layers. Furthermore an initial pilot study using O-isotope data is conducted on Ti-magnetite and plagioclase separates from gabbroic vs. ore rocks. Results are coupled with detailed thermodynamic modeling using the software PELE in order to further constrain Fe-Ti oxide ore layer formation. The intrusion is characterised by extreme depletion of PGEs relative to the coeval flood basalts and picrites. High Cu/Pd and Pd/Pt imply two separate stages of S-saturated and S-undersaturated depletion of PGEs. Pd is highly compatible in sulphide and is quickly scavenged by sulphide liquids resulting in an increase in Cu/Pd of the residual liquid. Furthermore decoupling of Pd and Pt can be achieved by either late stage hydrothermal alteration or through S-undersaturated stage of PGE depletion where Pt is scavenged by Pt-rich alloys or oxide minerals. I show that the latter is more likely. Fractionation modeling suggests that the Panzhihua parent magma formed at depth from original picritic magma. This is consistent with several other recent studies on other layered intrusions of the ELIP. Sr-Nd isotopic ratios indicate very little crustal contamination has occurred en route to the current chamber. Sr and Nd concentrations of footwall rocks are too low to produce any significant change in initial Sr and Nd isotopic ratios of the intruding basaltic magmas, indicating that crustal contamination will not be indicated by Sr-Nd isotopic ratios. Gradational change in the Sr-Nd isotope ratios across the MGZ provides strong evidence for formation in an open system by multiple replenishments of progressively less contaminated magmas from depth. Contamination is difficult to constrain but must be occurring prior to emplacement at the current level (low Sr and Nd contents of footwall). A gradational upward decrease in highly incompatible element across the MGZ can then be explained by continuous magma flow, which effectively removes the evolved intercumulus liquids from the growing cumulate pile at the base of the chamber. The initial stages of formation of the Panzhihua intrusion are interpreted to result from prolonged low volume pulses of magma into a slowly opening chamber. The timing of Fe-Ti oxide crystallisation is fundamental in the understanding of the petrogenesis of ore layers. Distinct geochemical variation in whole-rock Fe2O3/TiO2 and Zr/Nb indicates that Timagnetite is the dominant oxide within the lower ± 270 m of the intrusion whereas above this level both Ti-magnetite and ilmenite are present as cumulus phases. This is interpreted to indicate a variation in the fO2 where the lower intrusion crystallises at higher fO2 relative to that above this level. Silicates within the ore layers, in particular plagioclase, are highly embayed and resorped where in contact with Fe-Ti oxides. This characteristic of the silicate grains implies early crystallisation prior to Fe-Ti oxides with subsequent disequilibrium conditions resulting in resorption. Furthermore distinct reaction rims of kaersutite amphibole, Fo-enriched olivine, An-enriched plagioclase and pleonaste are observed. The abundance of amphibole suggests H2O involvement in this reaction and consumption of silicates. A model for parent magma crystallisation at various H2O contents indicates that plagioclase crystallisation temperature is very sensitive to H2O content of the parent magma. Plagioclase crystallises early for “dry” compositions but significantly later for “wet” compositions. Fe-Ti oxide ore layers are generally well layered, contain gabbroic xenoliths and are observed raversing/cross-cutting the cumulate stratigraphy. I present here a new model for ore layer formation in order to account for these distinct features of the ore layers. A model invoking multiple replenishments of magma with variable oxide microphenocryst content, H2O content and volume is proposed. Magma evolving in the plumbing system and fed to the Panzhihua chamber is variably enriched in H2O, which results in significantly different crystallisation paths. High H2O magmas (> 2 wt %) crystallise Fe-Ti oxides early whereas low H2O magmas (< 1 wt %) crystallise oxides late. Early pulses of H2O-poor magma crystallise a sequence of plag+cpx+Fe-Ti oxide (±ol). Later pulses of H2Orich magma subsequently intrude the partially crystallised cumulate sequence incorporating and consuming previously crystallised silicates with subsequent early crystallisation of Ti-magnetite and formation of ore layers. H2O-rich magmas likely have suspended Ti-magnetite microphenocrysts as well, which crystallise at depth in the plumbing system. This model can account for the various characteristic features of the Fe-Ti oxide ore layers at the Panzhihua intrusion as well as other Fe-Ti oxide ore bearing intrusions in the region.
- Full Text:
- Date Issued: 2013
Synthesis, characterisation and biological activity of 2-(methylthiomethyl)anilines, 2-(methylthio)anilines, their Schiff-base derivatives and metal(II) (Co, Ni, Cu) complexes
- Olalekan, Temitope Elizabeth
- Authors: Olalekan, Temitope Elizabeth
- Date: 2013
- Subjects: Aniline , Schiff bases , Ligands , Nuclear magnetic resonance spectroscopy , Chelates , X-ray crystallography , Antimalarials
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4562 , http://hdl.handle.net/10962/d1020868
- Description: A series of 31 sulfur-nitrogen donor ligands and 64 metal(II) complexes have been investigated. The thiomethylated aniline ligands 2–(methylthiomethyl)aniline 2MT and 2–(methylthio)aniline 2MA were synthesized with their substituted derivatives (-Me, -MeO, -Cl, -Br, -NO2) to serve as chelating agents. These ligands behave as bidentate ligands with SN donor group with Co(II), Ni(II) and Cu(II). The Co(II) and Ni(II) complexes have the ML2Cl2 molecular formula while the Cu(II) complexes formed with MLCl2 stoichiometry where L is the bidentate ligand. The ligands and their metal(II) complexes have been characterized by elemental analysis and with spectroscopic techniques. The trend observed in the NMR spectra and IR frequencies of the thiomethylated compounds shows there is a significant difference between the 2MT and 2MA series as a result of sulfur lone pairs extending the conjugation of the aromatic ring in the case of the latter. The effect of the position and electronic nature of ring substituent on the NMR shifts of the amine protons is discussed. The 6- and 5-membered chelate complexes formed by the 2MT and 2MA ligands respectively do not show significant diversity in their spectroscopic properties. From the elemental analysis for the Co(II) and Ni(II) complexes, their compositions reveal 1:2 M:L stoichiometry with 2 chlorine atoms from the respective metal salts. In addition, the spectroscopic data are largely indicative of tetragonally distorted structures for these solid complexes. The X-ray crystallography data reveal the Cu(II) complexes exist as square pyramidal dimers and with long Cu–Cl equitorial bonds fit into the tetragonally distorted octahedral structure. The electrolytic nature of Co(II) and Cu(II) complexes in DMF were found to be similar, they behave as non electrolytes in contrast to Ni(II) complexes which are 1:1 electrolytes. The electronic spectra of these metal(II) complexes were found to be different for both their solid forms and in solutions of DMF and DMSO and this has been discussed. The thiomethylated aniline ligands possess the amine and thioether groups which are present in many known biologically active compounds, hence the biological activity of the ligands and their metal complexes were tested against three strains of bacteria and one fungus. The methoxy-substituted derivatives were found to possess better inhibitory activity and this was similarly reflected in the metal(II) complexes. The activity of the complexes can be said to be in the order, Cu(II) > Co(II) > Ni(II). The Schiff-base derivatives were prepared from the ligands and para-methoxysalicylaldehyde and their Cu(II) complexes were synthesized in order to determine their biological activity. The Schiff-base ligands were found to be less active than their parent ligands. The Cu(II) complexes are not soluble in water, DMSO or DMF, as a result and could not be evaluated for their biological activity. Based on the good results from the antimicrobial evaluation, the antiplasmodial activity of some of the Co(II), Ni(II) and Cu(II) complexes of the thiomethylated ligands against Plasmodium falciparum (FCR-3) was determined. At 50 μM concentration level, the Cu(II) complexes show activity equal or better than the prophylactic chloroquine. The Cu(II) complexes with the methoxy-substituted demonstrated exceptional activity but their Co(II) and Ni(II) analogues did not show any activity. The cytotoxicity of the active Cu(II) complexes at 50 μM concentration was determined against the breast cancer cell line (MDA-MB-231). The compounds destroyed the cancer cell in the range of 28–40%, thus showing their preferred activity against the parasitic cell instead of the cancer cell. The selectivity demonstrated by these compounds have shown them to be potential antimalarial agents and this could be further investigated.
- Full Text:
- Date Issued: 2013
- Authors: Olalekan, Temitope Elizabeth
- Date: 2013
- Subjects: Aniline , Schiff bases , Ligands , Nuclear magnetic resonance spectroscopy , Chelates , X-ray crystallography , Antimalarials
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4562 , http://hdl.handle.net/10962/d1020868
- Description: A series of 31 sulfur-nitrogen donor ligands and 64 metal(II) complexes have been investigated. The thiomethylated aniline ligands 2–(methylthiomethyl)aniline 2MT and 2–(methylthio)aniline 2MA were synthesized with their substituted derivatives (-Me, -MeO, -Cl, -Br, -NO2) to serve as chelating agents. These ligands behave as bidentate ligands with SN donor group with Co(II), Ni(II) and Cu(II). The Co(II) and Ni(II) complexes have the ML2Cl2 molecular formula while the Cu(II) complexes formed with MLCl2 stoichiometry where L is the bidentate ligand. The ligands and their metal(II) complexes have been characterized by elemental analysis and with spectroscopic techniques. The trend observed in the NMR spectra and IR frequencies of the thiomethylated compounds shows there is a significant difference between the 2MT and 2MA series as a result of sulfur lone pairs extending the conjugation of the aromatic ring in the case of the latter. The effect of the position and electronic nature of ring substituent on the NMR shifts of the amine protons is discussed. The 6- and 5-membered chelate complexes formed by the 2MT and 2MA ligands respectively do not show significant diversity in their spectroscopic properties. From the elemental analysis for the Co(II) and Ni(II) complexes, their compositions reveal 1:2 M:L stoichiometry with 2 chlorine atoms from the respective metal salts. In addition, the spectroscopic data are largely indicative of tetragonally distorted structures for these solid complexes. The X-ray crystallography data reveal the Cu(II) complexes exist as square pyramidal dimers and with long Cu–Cl equitorial bonds fit into the tetragonally distorted octahedral structure. The electrolytic nature of Co(II) and Cu(II) complexes in DMF were found to be similar, they behave as non electrolytes in contrast to Ni(II) complexes which are 1:1 electrolytes. The electronic spectra of these metal(II) complexes were found to be different for both their solid forms and in solutions of DMF and DMSO and this has been discussed. The thiomethylated aniline ligands possess the amine and thioether groups which are present in many known biologically active compounds, hence the biological activity of the ligands and their metal complexes were tested against three strains of bacteria and one fungus. The methoxy-substituted derivatives were found to possess better inhibitory activity and this was similarly reflected in the metal(II) complexes. The activity of the complexes can be said to be in the order, Cu(II) > Co(II) > Ni(II). The Schiff-base derivatives were prepared from the ligands and para-methoxysalicylaldehyde and their Cu(II) complexes were synthesized in order to determine their biological activity. The Schiff-base ligands were found to be less active than their parent ligands. The Cu(II) complexes are not soluble in water, DMSO or DMF, as a result and could not be evaluated for their biological activity. Based on the good results from the antimicrobial evaluation, the antiplasmodial activity of some of the Co(II), Ni(II) and Cu(II) complexes of the thiomethylated ligands against Plasmodium falciparum (FCR-3) was determined. At 50 μM concentration level, the Cu(II) complexes show activity equal or better than the prophylactic chloroquine. The Cu(II) complexes with the methoxy-substituted demonstrated exceptional activity but their Co(II) and Ni(II) analogues did not show any activity. The cytotoxicity of the active Cu(II) complexes at 50 μM concentration was determined against the breast cancer cell line (MDA-MB-231). The compounds destroyed the cancer cell in the range of 28–40%, thus showing their preferred activity against the parasitic cell instead of the cancer cell. The selectivity demonstrated by these compounds have shown them to be potential antimalarial agents and this could be further investigated.
- Full Text:
- Date Issued: 2013
Ties that bind
- Authors: Tshisela, Namhla
- Date: 2012
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:20988 , http://hdl.handle.net/10962/5913
- Description: This collection of short stories about contemporary black South African women reveals their hopes and anxieties, and explores their relationships with themselves, their families, and the people around them. It sets out to challenge stereotypes about black women being browbeaten in a country riddled by poverty and disease by portraying women successfully forging their identities in society.
- Full Text:
- Date Issued: 2012
- Authors: Tshisela, Namhla
- Date: 2012
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:20988 , http://hdl.handle.net/10962/5913
- Description: This collection of short stories about contemporary black South African women reveals their hopes and anxieties, and explores their relationships with themselves, their families, and the people around them. It sets out to challenge stereotypes about black women being browbeaten in a country riddled by poverty and disease by portraying women successfully forging their identities in society.
- Full Text:
- Date Issued: 2012
An investigation of parental involvement in the development of their children's literacy in a rural Namibian school
- Authors: Siririka, Gisela
- Date: 2007
- Subjects: Education -- Namibia Education -- Parent participation -- Namibia Rural schools -- Namibia Community and school -- Namibia Literacy -- Social aspects -- Namibia Literacy -- Study and teaching -- Namibia Libraries and education -- Namibia
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1638 , http://hdl.handle.net/10962/d1003520
- Description: This study sought to investigate the involvement of parents in the development of their children’s literacy. The study was conducted in a rural school in the Omaheke region of Namibia, a school selected for reasons of representativeness and convenience. The research took the form of an interpretive case study focussing on a study sample of nine parents, their children, and one teacher in the Ngeama community. Data were collected through semi-structured interviews and then subjected to comprehensive descriptive analysis. The findings of the study indicate that parents in the Ngeama rural community have not been effectively involved in their children’s acquisition of literacy, for a number of reasons. These include the parents’ not feeling appropriately empowered to influence the development of their children’s literacy, the absence of environmental literacy programmes within the community, and the shortage of literacy materials such as newspapers and magazines. Perhaps the most important factor is that there is no public or school library in the Ngeama community. In view of these findings, the study recognizes a need for parental empowerment in terms of knowledge, skills, understanding and resources allocation regarding the education of their children. It recommends that a relationship of trust and understanding be built between the school and the community to ensure the sound development of literacy skills. The study further recommends the establishment of a library in order to enhance the literacy levels of teachers, parents and children alike.
- Full Text:
- Date Issued: 2007
- Authors: Siririka, Gisela
- Date: 2007
- Subjects: Education -- Namibia Education -- Parent participation -- Namibia Rural schools -- Namibia Community and school -- Namibia Literacy -- Social aspects -- Namibia Literacy -- Study and teaching -- Namibia Libraries and education -- Namibia
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1638 , http://hdl.handle.net/10962/d1003520
- Description: This study sought to investigate the involvement of parents in the development of their children’s literacy. The study was conducted in a rural school in the Omaheke region of Namibia, a school selected for reasons of representativeness and convenience. The research took the form of an interpretive case study focussing on a study sample of nine parents, their children, and one teacher in the Ngeama community. Data were collected through semi-structured interviews and then subjected to comprehensive descriptive analysis. The findings of the study indicate that parents in the Ngeama rural community have not been effectively involved in their children’s acquisition of literacy, for a number of reasons. These include the parents’ not feeling appropriately empowered to influence the development of their children’s literacy, the absence of environmental literacy programmes within the community, and the shortage of literacy materials such as newspapers and magazines. Perhaps the most important factor is that there is no public or school library in the Ngeama community. In view of these findings, the study recognizes a need for parental empowerment in terms of knowledge, skills, understanding and resources allocation regarding the education of their children. It recommends that a relationship of trust and understanding be built between the school and the community to ensure the sound development of literacy skills. The study further recommends the establishment of a library in order to enhance the literacy levels of teachers, parents and children alike.
- Full Text:
- Date Issued: 2007
The early proterozoic Makganyene glacial event in South Africa : its implication in sequence stratigraphy interpretations, paleoenvironmental conditions and iron and manganese ore deposition
- Authors: Polteau, Stéphane
- Date: 2005
- Subjects: Geology, Stratigraphic -- South Africa -- Northern Cape Geochemistry -- South Africa -- Northern Cape Paleogeography -- South Africa -- Northern Cape Petrology -- South Africa -- Northern Cape Ore deposits -- South Africa -- Northern Cape
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5039 , http://hdl.handle.net/10962/d1007612
- Description: The Makganyene Formation forms the base of the Postmasburg Group in the Transvaal Supergroup in the Griqualand West Basin. It consists of diamictites, sandstones, banded iron-formations (BIFs), shales, siltstones and carbonates. It is generally accepted that the Makganyene Formation rests on an erosive regional unconformity throughout the Northern Cape Province. However this study demonstrates that this stratigraphic relationship is not universal, and conformable contacts have been observed. One of the principal aims of this study is to identify the nature of the Makganyene basal contact throughout the Griqualand West Basin. Intensive fieldwork was carried out from Prieska in the south, to Danielskuil in the north. In the Sishen and Hotazel areas, only borehole material was available to assess the stratigraphy. The Griquatown Fault Zone delimits the boundary between the deep basin and platform facies. The Koegas Subgroup is only present south of the Griquatown Fault Zone, where it pinches out. However, the transition Griquatown BIFs-Koegas Subgroup occurs in lacustrine deposits on the Ghaap platform (Beukes, 1983). The Griquatown Fault Zone represents the edge of the basin, which corresponds to a hinge rather than a fault zone. The Makganyene Formation rests with a conformable contact on the Koegas Subgroup south of the Griquatown Hinge Zone, and north of it the Makganyene Formation lies unconformably on the Asbestos Hills Subgroup. The Makganyene Formation displays lateral facies changes that reflect the paleogeography of the Griqualand West Basin, and the development of ice sheets/shelves. The Ghaap platform is characterised by coarse immature sand interbedded with the diamictites. The clasts in this area contain local Asbestos Hills material and no dropstones are present. Such settings are typical of sediments that are being deposited below a grounded ice mass. At the Griquatown Hinge Zone, the sandstone lenses are smaller, and the clasts consist of chert, of which a great number are striated and faceted. In the Matsap area, the presence of dropstones is strong evidence for the presence of a floating ice shelf that released its material by basal melting. Further south, the Makganyene Formation contains stromatolitic bioherms that only form if clastic contamination is minimal and therefore the ice that transported the detritus to the basin did not extend far into open sea conditions. The base of the Hotazel Formation also contains diamictite levels. Dropstones have been identified, implying a glacial origin. The Hotazel diamictites are interbedded with hyaloclastites and BIFs. The Makganyene glacial event, therefore, was not restricted to the Makganyene Formation, but also included the Ongeluk Formation, through to the base of the Hotazel Formation. Petrographic studies of the Makganyene Formation and the base of the Hotazel Formation reveal mineral assemblages that are diagnostic of early to late diagenetic crystallisation and of low-grade metamorphism not exceeding the very low green-schist facies. The facies identified display the same sense of basin deepening, from shallow high-energy Hotazel area on the Ghaap platform, to the deep basin in the Matsap area. Whole-rock geochemical analyses reveal that the elemental composition of the Makganyene Formation is very similar to that of the Asbestos Hills BIFs, which were the most important source of clastic detritus for the Makganyene Formation. However, minor amounts of carbonates of the Campbellrand Subgroup, as well as a felsic crustal input from the Archean granitoid basement, made contributions. On the Ghaap platform, the Makganyene diamictite is enriched in iron, calcium, and magnesium, while in the deeper parts of the basin the diamictites are enriched in detrital elements, such as titanium and aluminium, which occur in the fine clay component. The Hotazel diamictite displays a distinct mafic volcanic input, related to the extrusion of the Ongeluk basaltic andesites, which was incorporated in the glacial sediments. Sequence stratigraphy is based on the recognition of contacts separating the different systems tracts that compose a depositional sequence. However, because the basal contact of the Makganyene Formation has not been properly identified in previous work, no correct model has been proposed so far. Therefore correlations between the Griqualand West and the Transvaal basins, based on lithostratigraphic similarities and extrapolations of unconformities, have to be reviewed, especially since the publication of new radiometric ages contradict all previously proposed correlations. It is proposed here that the Transvaal Supergroup in the Griqualand West Basin represents a continuous depositional event that lasted about 200 Ma. The Makganyene glacial event occurred during changing conditions in the chemistries of the atmosphere and ocean, and in the continental configuration. A Snowball Earth event has been proposed as the causative process of such paleoenvironmental changes. However, evidence presented here of less dramatic glacial conditions, with areas of ice-free waters, implies an alternative to the Snowball Earth event. The paleoenvironmental changes are thought to represent a transition from an anaerobic to aerobic atmosphere, that was responsible for the global cooling of the surface of the Earth, Such a glacial event may have aided in the large-scale precipitation of iron and manganese in areas of intense upwellings.
- Full Text:
- Date Issued: 2005
- Authors: Polteau, Stéphane
- Date: 2005
- Subjects: Geology, Stratigraphic -- South Africa -- Northern Cape Geochemistry -- South Africa -- Northern Cape Paleogeography -- South Africa -- Northern Cape Petrology -- South Africa -- Northern Cape Ore deposits -- South Africa -- Northern Cape
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5039 , http://hdl.handle.net/10962/d1007612
- Description: The Makganyene Formation forms the base of the Postmasburg Group in the Transvaal Supergroup in the Griqualand West Basin. It consists of diamictites, sandstones, banded iron-formations (BIFs), shales, siltstones and carbonates. It is generally accepted that the Makganyene Formation rests on an erosive regional unconformity throughout the Northern Cape Province. However this study demonstrates that this stratigraphic relationship is not universal, and conformable contacts have been observed. One of the principal aims of this study is to identify the nature of the Makganyene basal contact throughout the Griqualand West Basin. Intensive fieldwork was carried out from Prieska in the south, to Danielskuil in the north. In the Sishen and Hotazel areas, only borehole material was available to assess the stratigraphy. The Griquatown Fault Zone delimits the boundary between the deep basin and platform facies. The Koegas Subgroup is only present south of the Griquatown Fault Zone, where it pinches out. However, the transition Griquatown BIFs-Koegas Subgroup occurs in lacustrine deposits on the Ghaap platform (Beukes, 1983). The Griquatown Fault Zone represents the edge of the basin, which corresponds to a hinge rather than a fault zone. The Makganyene Formation rests with a conformable contact on the Koegas Subgroup south of the Griquatown Hinge Zone, and north of it the Makganyene Formation lies unconformably on the Asbestos Hills Subgroup. The Makganyene Formation displays lateral facies changes that reflect the paleogeography of the Griqualand West Basin, and the development of ice sheets/shelves. The Ghaap platform is characterised by coarse immature sand interbedded with the diamictites. The clasts in this area contain local Asbestos Hills material and no dropstones are present. Such settings are typical of sediments that are being deposited below a grounded ice mass. At the Griquatown Hinge Zone, the sandstone lenses are smaller, and the clasts consist of chert, of which a great number are striated and faceted. In the Matsap area, the presence of dropstones is strong evidence for the presence of a floating ice shelf that released its material by basal melting. Further south, the Makganyene Formation contains stromatolitic bioherms that only form if clastic contamination is minimal and therefore the ice that transported the detritus to the basin did not extend far into open sea conditions. The base of the Hotazel Formation also contains diamictite levels. Dropstones have been identified, implying a glacial origin. The Hotazel diamictites are interbedded with hyaloclastites and BIFs. The Makganyene glacial event, therefore, was not restricted to the Makganyene Formation, but also included the Ongeluk Formation, through to the base of the Hotazel Formation. Petrographic studies of the Makganyene Formation and the base of the Hotazel Formation reveal mineral assemblages that are diagnostic of early to late diagenetic crystallisation and of low-grade metamorphism not exceeding the very low green-schist facies. The facies identified display the same sense of basin deepening, from shallow high-energy Hotazel area on the Ghaap platform, to the deep basin in the Matsap area. Whole-rock geochemical analyses reveal that the elemental composition of the Makganyene Formation is very similar to that of the Asbestos Hills BIFs, which were the most important source of clastic detritus for the Makganyene Formation. However, minor amounts of carbonates of the Campbellrand Subgroup, as well as a felsic crustal input from the Archean granitoid basement, made contributions. On the Ghaap platform, the Makganyene diamictite is enriched in iron, calcium, and magnesium, while in the deeper parts of the basin the diamictites are enriched in detrital elements, such as titanium and aluminium, which occur in the fine clay component. The Hotazel diamictite displays a distinct mafic volcanic input, related to the extrusion of the Ongeluk basaltic andesites, which was incorporated in the glacial sediments. Sequence stratigraphy is based on the recognition of contacts separating the different systems tracts that compose a depositional sequence. However, because the basal contact of the Makganyene Formation has not been properly identified in previous work, no correct model has been proposed so far. Therefore correlations between the Griqualand West and the Transvaal basins, based on lithostratigraphic similarities and extrapolations of unconformities, have to be reviewed, especially since the publication of new radiometric ages contradict all previously proposed correlations. It is proposed here that the Transvaal Supergroup in the Griqualand West Basin represents a continuous depositional event that lasted about 200 Ma. The Makganyene glacial event occurred during changing conditions in the chemistries of the atmosphere and ocean, and in the continental configuration. A Snowball Earth event has been proposed as the causative process of such paleoenvironmental changes. However, evidence presented here of less dramatic glacial conditions, with areas of ice-free waters, implies an alternative to the Snowball Earth event. The paleoenvironmental changes are thought to represent a transition from an anaerobic to aerobic atmosphere, that was responsible for the global cooling of the surface of the Earth, Such a glacial event may have aided in the large-scale precipitation of iron and manganese in areas of intense upwellings.
- Full Text:
- Date Issued: 2005
An interpretive use of drawings to explore the lived experiences of orphaned children living with HIV/AIDS in South Africa
- Authors: Steenveld, Clint Michael
- Date: 2004
- Subjects: AIDS (Disease) -- South Africa AIDS (Disease) -- Social aspects -- South Africa HIV infections -- South Africa HIV infections -- Social aspects -- South Africa AIDS (Disease) -- Psychological aspects HIV infections -- Psychological aspects -- South Africa AIDS (Disease) in children -- Psychological aspects -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3099 , http://hdl.handle.net/10962/d1004374
- Description: Against the backdrop of the growing problem of AIDS orphans in South Africa and greater sub-Saharan Africa, this qualitative enquiry examines the lives of three South African orphaned children living with HIV / AIDS in a children's home in Cape Town. It aims to generate rich, child-centred descriptions of some of the significant experiences of the children's lives. Drawings, dialogue and narrative were employed to generate the primary data. This was supplemented by collateral interviews and other relevant records, e.g. medical and biographical. Existential-phenomenological theory informed the approach to data collection and analysis. Each child produced a series often to twelve impromptu drawings over a period often weeks. These drawings and transcripts of the children's verbal descriptions of their drawings were extensively analysed. Significant themes for each participant as well as themes common to all three were identified. Some of the central themes emerging include loss, abandonment, death, disease awareness and coping. The children's ability to develop adaptive coping mechanisms and resilience in the face of traumatic loss and terminal illness was a particularly outstanding feature of the findings. Recommendations are made regarding future research to address the lack of qualitative, child-focused investigations as well as appropriate interventions for addressing the psychosocial needs of orphaned children living with HIV/AIDS.
- Full Text:
- Date Issued: 2004
- Authors: Steenveld, Clint Michael
- Date: 2004
- Subjects: AIDS (Disease) -- South Africa AIDS (Disease) -- Social aspects -- South Africa HIV infections -- South Africa HIV infections -- Social aspects -- South Africa AIDS (Disease) -- Psychological aspects HIV infections -- Psychological aspects -- South Africa AIDS (Disease) in children -- Psychological aspects -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3099 , http://hdl.handle.net/10962/d1004374
- Description: Against the backdrop of the growing problem of AIDS orphans in South Africa and greater sub-Saharan Africa, this qualitative enquiry examines the lives of three South African orphaned children living with HIV / AIDS in a children's home in Cape Town. It aims to generate rich, child-centred descriptions of some of the significant experiences of the children's lives. Drawings, dialogue and narrative were employed to generate the primary data. This was supplemented by collateral interviews and other relevant records, e.g. medical and biographical. Existential-phenomenological theory informed the approach to data collection and analysis. Each child produced a series often to twelve impromptu drawings over a period often weeks. These drawings and transcripts of the children's verbal descriptions of their drawings were extensively analysed. Significant themes for each participant as well as themes common to all three were identified. Some of the central themes emerging include loss, abandonment, death, disease awareness and coping. The children's ability to develop adaptive coping mechanisms and resilience in the face of traumatic loss and terminal illness was a particularly outstanding feature of the findings. Recommendations are made regarding future research to address the lack of qualitative, child-focused investigations as well as appropriate interventions for addressing the psychosocial needs of orphaned children living with HIV/AIDS.
- Full Text:
- Date Issued: 2004
The pyrrolizidine alkaloids of Senecio chrysocoma and Senecio paniculatus
- Authors: Logie, Catherine Gwynedd
- Date: 1996
- Subjects: Senecio -- Analysis Pyrrolizidines Botanical chemistry
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4339 , http://hdl.handle.net/10962/d1005000
- Description: In order to compare the pyrrolizidine alkaloid content of two closely related species, Senecio chrysocoma and S. paniculatus, nine populations of plants distributed between the two species, were examined. Three novel pyrrolizidine alkaloids, 7ß-angelyl-l-methylene-8∝-pyrrolizidine, 7ß-angelyl-l-methylene-8∝-pyrrolizidine and 7ß-angelyl-l-methyleneSO!-pyrrolizidine-4-oxide, as well as eight known pyrrolizidine alkaloids, 7-angelylhastanecine, 9-angelylhastanecine, 7-angelylplatynecine, 9-angelylplatynecine, 9-angelylplatynecine-4-oxide, sarracine, neosarracine and retrorsine, were isolated and identified by NMR and GC-MS techniques. Traces of five tiglyl isomers, 9-tiglylplatynecine, 9-tigl ylplatynecine-4-oxide, 7ß-tiglyl-l-methylene-8∝-pyrrolizidine, sarranicine and neosarranicine, were also isolated and tentatively identified; however, these compounds could have been artefacts of the extraction and analytical procedures. While both species of plant investigated, S. chrysocoma and S. paniculatus, were found to be morphologically different, their pyrrolizidine alkaloid content was, in fact, very similar. The presence of retrorsine in S. paniculatus plant extracts, but not in those from S. chrysocoma plants, was the only major chemical difference observed. It is perhaps significant that retrorsine was the only macrocyclic pyrrolizidine to be identified. A comprehensive, computerised database of physical data for pyrrolizidine alkaloids has been compiled, which has facilitated the identification of new pyrrolizidines and the examination of trends in proton and carbon-13 NMR data for pyrrolizidine alkaloids. A stereospecific synthesis of 7ß-angelyl-l-methylene-8∝-pyrrolizidine was undertaken toconfirm the absolute stereochemistry of the product isolated from S. chrysocoma and S. paniculatus. An inseparable 5:2 mixture of 7ß-angelyl-l-methylene-8∝-pyrrolizidine and 7ß-angelyl-l,2-didehydro-l-methyl-8∝-pyrrolizidine, together with a small amount of tiglyl isomer, was finally synthesised. The application of various chiral differentiating chromatographic and spectroscopic techniques confirmed that both the natural and synthetic products had the same stereochemistry, permitting the natural alkaloid to be identified as 7ß-angelyl-methylene-8∝-pyrrol izidine
- Full Text:
- Date Issued: 1996
- Authors: Logie, Catherine Gwynedd
- Date: 1996
- Subjects: Senecio -- Analysis Pyrrolizidines Botanical chemistry
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4339 , http://hdl.handle.net/10962/d1005000
- Description: In order to compare the pyrrolizidine alkaloid content of two closely related species, Senecio chrysocoma and S. paniculatus, nine populations of plants distributed between the two species, were examined. Three novel pyrrolizidine alkaloids, 7ß-angelyl-l-methylene-8∝-pyrrolizidine, 7ß-angelyl-l-methylene-8∝-pyrrolizidine and 7ß-angelyl-l-methyleneSO!-pyrrolizidine-4-oxide, as well as eight known pyrrolizidine alkaloids, 7-angelylhastanecine, 9-angelylhastanecine, 7-angelylplatynecine, 9-angelylplatynecine, 9-angelylplatynecine-4-oxide, sarracine, neosarracine and retrorsine, were isolated and identified by NMR and GC-MS techniques. Traces of five tiglyl isomers, 9-tiglylplatynecine, 9-tigl ylplatynecine-4-oxide, 7ß-tiglyl-l-methylene-8∝-pyrrolizidine, sarranicine and neosarranicine, were also isolated and tentatively identified; however, these compounds could have been artefacts of the extraction and analytical procedures. While both species of plant investigated, S. chrysocoma and S. paniculatus, were found to be morphologically different, their pyrrolizidine alkaloid content was, in fact, very similar. The presence of retrorsine in S. paniculatus plant extracts, but not in those from S. chrysocoma plants, was the only major chemical difference observed. It is perhaps significant that retrorsine was the only macrocyclic pyrrolizidine to be identified. A comprehensive, computerised database of physical data for pyrrolizidine alkaloids has been compiled, which has facilitated the identification of new pyrrolizidines and the examination of trends in proton and carbon-13 NMR data for pyrrolizidine alkaloids. A stereospecific synthesis of 7ß-angelyl-l-methylene-8∝-pyrrolizidine was undertaken toconfirm the absolute stereochemistry of the product isolated from S. chrysocoma and S. paniculatus. An inseparable 5:2 mixture of 7ß-angelyl-l-methylene-8∝-pyrrolizidine and 7ß-angelyl-l,2-didehydro-l-methyl-8∝-pyrrolizidine, together with a small amount of tiglyl isomer, was finally synthesised. The application of various chiral differentiating chromatographic and spectroscopic techniques confirmed that both the natural and synthetic products had the same stereochemistry, permitting the natural alkaloid to be identified as 7ß-angelyl-methylene-8∝-pyrrol izidine
- Full Text:
- Date Issued: 1996
Collaborative teacher participation in curriculum development : a case study in junior secondary general science (January 1991-November 1991)
- Authors: Naidoo, Premnandh
- Date: 1993
- Subjects: Science -- Study and teaching (Secondary) -- South Africa Curriculum planning -- South Africa Environmental education -- South Africa
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1451 , http://hdl.handle.net/10962/d1003332
- Description: This research report describes an investigation that involved the collaborative participation of teachers in the redevelopment of parts of the Junior Secondary General Science syllabus. The redevelopment tried to implement environmental education as an innovation. There are two central assumptions that the investigation has made. The first assumption is that the the present Junior Secondary General Science syllabus lacks environmental relevance and therefore the pupils are inadequately prepared to deal with environmental problems. The introduction of a curriculum innovation like environmental education has the potential to bring greater environmental relevance to the syllabus. The second is that such an innovation can be more successfully implemented at schools if it involves the collaborative participation of teachers in the redevelopment of the syllabus. This assumption is made since evidence suggests that curriculum change can be a process of social reconstructive process when it takes place in situ and where teachers and pupils reshape the curriculum in the classroom as the teaching and learning progresses. An action research approach was selected since it is compatible with collaborative teacher, participation in curriculum development. The research design involved three parallel case studies: 1. Clermont Zone, 2. Durban Teachers Centre, 3. Edgewood College. The research confirmed that the Junior Secondary General Science syllabus is perceived by teachers to lack environmental relevance; that teachers, while initially resisting participation in the curriculum development process, were willing to participate if it revolved around their curriculum problems. Significant features of collaborative teacher participation in curriculum development seem to be the co-creation of context by the teachers, the need for institutional support, the production of curriculum materials and the need for networking and intercontextual dialogue. Teachers initially had limited curriculum development skills which needed to be developed. This research process has implications for practical actions 'to enable' the transformation of existing curriculums, and assisting the development of a more democratic and effective education system.
- Full Text:
- Date Issued: 1993
- Authors: Naidoo, Premnandh
- Date: 1993
- Subjects: Science -- Study and teaching (Secondary) -- South Africa Curriculum planning -- South Africa Environmental education -- South Africa
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1451 , http://hdl.handle.net/10962/d1003332
- Description: This research report describes an investigation that involved the collaborative participation of teachers in the redevelopment of parts of the Junior Secondary General Science syllabus. The redevelopment tried to implement environmental education as an innovation. There are two central assumptions that the investigation has made. The first assumption is that the the present Junior Secondary General Science syllabus lacks environmental relevance and therefore the pupils are inadequately prepared to deal with environmental problems. The introduction of a curriculum innovation like environmental education has the potential to bring greater environmental relevance to the syllabus. The second is that such an innovation can be more successfully implemented at schools if it involves the collaborative participation of teachers in the redevelopment of the syllabus. This assumption is made since evidence suggests that curriculum change can be a process of social reconstructive process when it takes place in situ and where teachers and pupils reshape the curriculum in the classroom as the teaching and learning progresses. An action research approach was selected since it is compatible with collaborative teacher, participation in curriculum development. The research design involved three parallel case studies: 1. Clermont Zone, 2. Durban Teachers Centre, 3. Edgewood College. The research confirmed that the Junior Secondary General Science syllabus is perceived by teachers to lack environmental relevance; that teachers, while initially resisting participation in the curriculum development process, were willing to participate if it revolved around their curriculum problems. Significant features of collaborative teacher participation in curriculum development seem to be the co-creation of context by the teachers, the need for institutional support, the production of curriculum materials and the need for networking and intercontextual dialogue. Teachers initially had limited curriculum development skills which needed to be developed. This research process has implications for practical actions 'to enable' the transformation of existing curriculums, and assisting the development of a more democratic and effective education system.
- Full Text:
- Date Issued: 1993
Some theoretical considerations in applying cost-benefit analysis to Black education in South Africa
- Authors: Hosking, Stephen Gerald
- Date: 1983
- Subjects: Cost effectiveness , Black people -- Education -- South Africa -- Economic aspects , Education -- Economic aspects -- South Africa , Education -- Finance -- South Africa
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:1047 , http://hdl.handle.net/10962/d1006150 , Cost effectiveness , Black people -- Education -- South Africa -- Economic aspects , Education -- Economic aspects -- South Africa , Education -- Finance -- South Africa
- Description: From introduction: In this thesis some of the economic theory underlying the application of cost-benefit analysis to education is considered with the view to discussing its relevance to the field of educational provision for Black people in South Africa. The fact that educational facilities available to Blacks are so vastly inferior to those of the Whites has given rise to virtual consensus that more has to be provided for the Black population. The economic implications of education are frequently cited to support this viewpoint. Using (a ) the theoretical bases established in chapters 1 and 2, (b) the review of the rate of return to education studies in chapter 3 and (c) the broader socio-economic considerations introduced in chapter 4, it is concluded that this viewpoint is not necessarily well founded in South Africa and that the potential for greater use of the techniques described, is far from exhausted.
- Full Text:
- Date Issued: 1983
Some theoretical considerations in applying cost-benefit analysis to Black education in South Africa
- Authors: Hosking, Stephen Gerald
- Date: 1983
- Subjects: Cost effectiveness , Black people -- Education -- South Africa -- Economic aspects , Education -- Economic aspects -- South Africa , Education -- Finance -- South Africa
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:1047 , http://hdl.handle.net/10962/d1006150 , Cost effectiveness , Black people -- Education -- South Africa -- Economic aspects , Education -- Economic aspects -- South Africa , Education -- Finance -- South Africa
- Description: From introduction: In this thesis some of the economic theory underlying the application of cost-benefit analysis to education is considered with the view to discussing its relevance to the field of educational provision for Black people in South Africa. The fact that educational facilities available to Blacks are so vastly inferior to those of the Whites has given rise to virtual consensus that more has to be provided for the Black population. The economic implications of education are frequently cited to support this viewpoint. Using (a ) the theoretical bases established in chapters 1 and 2, (b) the review of the rate of return to education studies in chapter 3 and (c) the broader socio-economic considerations introduced in chapter 4, it is concluded that this viewpoint is not necessarily well founded in South Africa and that the potential for greater use of the techniques described, is far from exhausted.
- Full Text:
- Date Issued: 1983
The development and failure of the Eastern Cape separatist movement with special reference to John Paterson
- Authors: Stead, J L
- Date: 1974
- Subjects: Paterson, John, 1822-1880 , Cape of Good Hope (South Africa) -- Politics and government -- 1795-1872 , Eastern Cape (South Africa) -- History -- Autonomy and independence movements , Stormberg Range Region (South Africa) -- History
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2593 , http://hdl.handle.net/10962/d1007343
- Description: From Preface: In 1960 Pamela Ffolliott and E.L.H. Croft wrote a biograpby of John Paterson entitled One Titan at a Time. This concentrated mainly on his business activities and his civic role to the virtual exclusion of his political opinions and career even though contemporaries often regarded him as second only to John X. Merriman. The result of diligent enquiry for further biographical detail both in South Africa and in the United Kingdom has been disappointing. A close examination of such evidence as there is, suggests that his political abilities have been over-rated rather than under-rated. It is now nearly forty years since the study of separatism was first seriously undertaken. The period 1854-72 was studied by N.H. Taylor (M.A. Thesis, University of Cape Town, 1938) and D.B. Sole undertook a broader survey (M.A. Thesis, University of South Africa (R.U.C.), 1939). Neither study used the Godlonton papers. The Godlonton-White correspondence is at Rhodes House, Oxford and this mainly concerns business matters and news of prominent local people. The collection of Godlonton papers housed in the Historical Papers section of the Library of the University of the Witwatersrand proved more interesting. The use of these papers made it possible to make a new approach to the critical period of representative government and to explore in more detail lines suggested in part by J .L. McCracken in the more general study, The Cape Parliament 1854-1910 published in 1967. Yet because in many cases the leaders of the movement after 1854 carried into the new era ideas and attitudes formed in earlier years, it was necessary to consider also the origins of the separatist impulse. Separatism had many roots: as a term it had many meanings. Clearly the meaning attached to the word varied from time to time, from place to place and even from person to person. The goal varied too. Sometimes the Eastern Province wanted to move the centre of government from Cape Town; sometimes the cry was for a completely separate colony to be established in the East; sometimes the theme was federal devolution of powers, to a resident government. Indeed among the many reasons for the failure of the separatist movement was the inability of the Easterners to agree among themselves about what they were seeking. This exposed and emphasised their political ineptitude.
- Full Text:
- Date Issued: 1974
- Authors: Stead, J L
- Date: 1974
- Subjects: Paterson, John, 1822-1880 , Cape of Good Hope (South Africa) -- Politics and government -- 1795-1872 , Eastern Cape (South Africa) -- History -- Autonomy and independence movements , Stormberg Range Region (South Africa) -- History
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2593 , http://hdl.handle.net/10962/d1007343
- Description: From Preface: In 1960 Pamela Ffolliott and E.L.H. Croft wrote a biograpby of John Paterson entitled One Titan at a Time. This concentrated mainly on his business activities and his civic role to the virtual exclusion of his political opinions and career even though contemporaries often regarded him as second only to John X. Merriman. The result of diligent enquiry for further biographical detail both in South Africa and in the United Kingdom has been disappointing. A close examination of such evidence as there is, suggests that his political abilities have been over-rated rather than under-rated. It is now nearly forty years since the study of separatism was first seriously undertaken. The period 1854-72 was studied by N.H. Taylor (M.A. Thesis, University of Cape Town, 1938) and D.B. Sole undertook a broader survey (M.A. Thesis, University of South Africa (R.U.C.), 1939). Neither study used the Godlonton papers. The Godlonton-White correspondence is at Rhodes House, Oxford and this mainly concerns business matters and news of prominent local people. The collection of Godlonton papers housed in the Historical Papers section of the Library of the University of the Witwatersrand proved more interesting. The use of these papers made it possible to make a new approach to the critical period of representative government and to explore in more detail lines suggested in part by J .L. McCracken in the more general study, The Cape Parliament 1854-1910 published in 1967. Yet because in many cases the leaders of the movement after 1854 carried into the new era ideas and attitudes formed in earlier years, it was necessary to consider also the origins of the separatist impulse. Separatism had many roots: as a term it had many meanings. Clearly the meaning attached to the word varied from time to time, from place to place and even from person to person. The goal varied too. Sometimes the Eastern Province wanted to move the centre of government from Cape Town; sometimes the cry was for a completely separate colony to be established in the East; sometimes the theme was federal devolution of powers, to a resident government. Indeed among the many reasons for the failure of the separatist movement was the inability of the Easterners to agree among themselves about what they were seeking. This exposed and emphasised their political ineptitude.
- Full Text:
- Date Issued: 1974
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