The enzymology of enhanced hydrolysis within the biosulphidogenic recycling sludge bed reactor (RSBR)
- Authors: Enongene, Godlove Nkwelle
- Date: 2004
- Subjects: Hydrolysis , Sewage sludge , Sewage -- Purification -- Anaerobic treatment , Water -- Purification -- Biological treatment
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4132 , http://hdl.handle.net/10962/d1015744
- Description: The hydrolysis of complex organic heteropolymers contained in municipal wastewater to simpler monomers by extracellular hydrolytic enzymes is generally considered the rate-limiting step of the biodegradation process. Previous studies of the Recycling Sludge Bed Reactor (RSBR) revealed that the hydrolysis of complex particulate organics, such as those contained in primary sludge (PS), was enhanced under anaerobic biosulphidogenic conditions. Although the mechanism was not fully understood, it appeared to involve the interaction of sulfide and sludge flocs. The current study was conducted using a 3500 ml laboratory-scale RSBR fed sieved PS at a loading rate of 0.5 kg COD/m³.day and an initial chemical oxygen demand (COD) to sulfate ratio (COD:SO₄) of 1:1. There was no significant accumulation of undigested sludge in the reactor over the 60-day experimental period and the quantity of SO₄ reduced indicated that the yield of soluble products from PS was at least as high as those reported previously for this system (> 50%). In the current study, the specific activities of a range of extracellular hydrolytic enzymes (L-alanine aminopeptidase, L-leucine aminopeptidase, arylsulphatase, α-glucosidase, β- glucosidase, protease and lipase) were monitored in a sulfide gradient within a biosulphidogenic RSBR. Data obtained indicated that the specific enzymatic activities increased with the depth of the RSBR and also correlated with a number of the physicochemical parameters including sulfide, alkalinity and sulfate. The activities of α- glucosidase and β-glucosidase were higher than that of the other enzymes studied. Lipase activity was relatively low and studies conducted on the enzyme-enzyme interaction using specific enzyme inhibitors indicated that lipases were probably being digested by the proteases. Further studies to determine the impact of sulfide on the enzymes, showed an increase in the enzyme activity with increasing sulfide concentration. Possible direct affects were investigated by looking for changes in the Michaelis constant (Km) and the maximal velocity (Vmax) of the crude enzymes with varying sulfide concentrations (250, 400 and 500 mg/l) using natural and synthetic substrates. The results showed no significant difference in both the Km and the Vmax for any of the hydrolytic enzymes except for the protease. The latter showed a statistically significant increase in the Km with increasing sulfide concentration. Although this indicated a direct interaction, this difference was not large enough to be of biochemical significance and was consequently not solely responsible for the enhanced hydrolysis observed in the RSBR. Investigation into the floc characteristics indicated that the biosulphidogenic RSBR flocs were generally small in size and became more dendritic with the depth of the RSBR. Based on the above data, the previously proposed descriptive models of enhanced hydrolysis of particulate organic matter in a biosulphidogenic RSBR has been revised. It is thought that the effect of sulfide on the hydrolysis step is primarily indirect and that the reduction in floc size and alteration of the floc shape to a more dendritic form is central to the success of the process.
- Full Text:
- Authors: Enongene, Godlove Nkwelle
- Date: 2004
- Subjects: Hydrolysis , Sewage sludge , Sewage -- Purification -- Anaerobic treatment , Water -- Purification -- Biological treatment
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4132 , http://hdl.handle.net/10962/d1015744
- Description: The hydrolysis of complex organic heteropolymers contained in municipal wastewater to simpler monomers by extracellular hydrolytic enzymes is generally considered the rate-limiting step of the biodegradation process. Previous studies of the Recycling Sludge Bed Reactor (RSBR) revealed that the hydrolysis of complex particulate organics, such as those contained in primary sludge (PS), was enhanced under anaerobic biosulphidogenic conditions. Although the mechanism was not fully understood, it appeared to involve the interaction of sulfide and sludge flocs. The current study was conducted using a 3500 ml laboratory-scale RSBR fed sieved PS at a loading rate of 0.5 kg COD/m³.day and an initial chemical oxygen demand (COD) to sulfate ratio (COD:SO₄) of 1:1. There was no significant accumulation of undigested sludge in the reactor over the 60-day experimental period and the quantity of SO₄ reduced indicated that the yield of soluble products from PS was at least as high as those reported previously for this system (> 50%). In the current study, the specific activities of a range of extracellular hydrolytic enzymes (L-alanine aminopeptidase, L-leucine aminopeptidase, arylsulphatase, α-glucosidase, β- glucosidase, protease and lipase) were monitored in a sulfide gradient within a biosulphidogenic RSBR. Data obtained indicated that the specific enzymatic activities increased with the depth of the RSBR and also correlated with a number of the physicochemical parameters including sulfide, alkalinity and sulfate. The activities of α- glucosidase and β-glucosidase were higher than that of the other enzymes studied. Lipase activity was relatively low and studies conducted on the enzyme-enzyme interaction using specific enzyme inhibitors indicated that lipases were probably being digested by the proteases. Further studies to determine the impact of sulfide on the enzymes, showed an increase in the enzyme activity with increasing sulfide concentration. Possible direct affects were investigated by looking for changes in the Michaelis constant (Km) and the maximal velocity (Vmax) of the crude enzymes with varying sulfide concentrations (250, 400 and 500 mg/l) using natural and synthetic substrates. The results showed no significant difference in both the Km and the Vmax for any of the hydrolytic enzymes except for the protease. The latter showed a statistically significant increase in the Km with increasing sulfide concentration. Although this indicated a direct interaction, this difference was not large enough to be of biochemical significance and was consequently not solely responsible for the enhanced hydrolysis observed in the RSBR. Investigation into the floc characteristics indicated that the biosulphidogenic RSBR flocs were generally small in size and became more dendritic with the depth of the RSBR. Based on the above data, the previously proposed descriptive models of enhanced hydrolysis of particulate organic matter in a biosulphidogenic RSBR has been revised. It is thought that the effect of sulfide on the hydrolysis step is primarily indirect and that the reduction in floc size and alteration of the floc shape to a more dendritic form is central to the success of the process.
- Full Text:
The enzymology of sludge solubilisation under biosulphidogenic conditions : isolation, characterisation and partial purification of endoglucanases
- Authors: Oyekola, Oluwaseun Oyekanmi
- Date: 2004
- Subjects: Sewage -- Purification -- Anaerobic treatment , Anaerobic bacteria , Sewage sludge , Hydrolysis
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3921 , http://hdl.handle.net/10962/d1003980 , Sewage -- Purification -- Anaerobic treatment , Anaerobic bacteria , Sewage sludge , Hydrolysis
- Description: Endoglucanases play an important function in cellulose hydrolysis and catalyse the initial attack on the polymer by randomly hydrolysing the β-1,4 glucosidic bonds within the amorphous regions of cellulose chains. Cellulolytic bacteria have been isolated and characterised from the sewage sludge and the activation of several hydrolytic enzymes under biosulphidogenic conditions of sewage hydrolysis has been reported. The aims of this study were to: identify, induce production, locate and isolate, characterise (physicochemical and kinetic) and purify endoglucanases from anaerobic biosulphidogenic sludge. The endoglucanase activities were shown to be associated with the pellet particulate matter and exhibited a pH optimum of 6 and temperature optimum of 50 °C. The enzymes were thermally more stable when immobilised to the floc matrix of the sludge than when they were released into the aqueous solution via sonication. For both immobilised and released enzymes, sulphate was slightly inhibitory; activity was reduced to 84 % and 77.5 % of the initial activity at sulphate concentrations between 200 and 1000 mg/l, respectively. Sulphite was stimulatory to the immobilised enzymes between 200 and 1000 mg/l. Sulphide stimulated the activities of the immobilised endoglucanases, but inhibited activities of the soluble enzymes above 200 mg/l. The enzyme fraction did not hydrolyse avicel (a crystalline substrate), indicating the absence of any exocellulase activity. For CMC (carboxymethylcellulose) and HEC (hydroxylethylcellulose) the enzyme had K_m,app_ values of 4 and 5.1 mg/ml respectively and V_max,app_ values of 0.297 and 0.185 μmol/min/ml respectively. Divalent ions (Cu²⁺, Ni²⁺ and Zn²⁺) proved to be inhibitory while Fe²⁺, Mg²⁺ and Ca²⁺ stimulated the enzyme at concentrations between 200 and 1000 mg/l. All the volatile fatty acids studied (acetic acid, butyric acid, propionic acid and valeric acid) inhibited the enzymes, with acetic acid eliciting the highest degree of inhibition. Sonication released ~74.9 % of the total enzyme activities into solution and this was partially purified by PEG 20 000 concentration followed by DEAE-Cellulose ion exchange chromatography, which resulted in an appreciable purity as measured by the purification factor, 25.4 fold.
- Full Text:
- Authors: Oyekola, Oluwaseun Oyekanmi
- Date: 2004
- Subjects: Sewage -- Purification -- Anaerobic treatment , Anaerobic bacteria , Sewage sludge , Hydrolysis
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3921 , http://hdl.handle.net/10962/d1003980 , Sewage -- Purification -- Anaerobic treatment , Anaerobic bacteria , Sewage sludge , Hydrolysis
- Description: Endoglucanases play an important function in cellulose hydrolysis and catalyse the initial attack on the polymer by randomly hydrolysing the β-1,4 glucosidic bonds within the amorphous regions of cellulose chains. Cellulolytic bacteria have been isolated and characterised from the sewage sludge and the activation of several hydrolytic enzymes under biosulphidogenic conditions of sewage hydrolysis has been reported. The aims of this study were to: identify, induce production, locate and isolate, characterise (physicochemical and kinetic) and purify endoglucanases from anaerobic biosulphidogenic sludge. The endoglucanase activities were shown to be associated with the pellet particulate matter and exhibited a pH optimum of 6 and temperature optimum of 50 °C. The enzymes were thermally more stable when immobilised to the floc matrix of the sludge than when they were released into the aqueous solution via sonication. For both immobilised and released enzymes, sulphate was slightly inhibitory; activity was reduced to 84 % and 77.5 % of the initial activity at sulphate concentrations between 200 and 1000 mg/l, respectively. Sulphite was stimulatory to the immobilised enzymes between 200 and 1000 mg/l. Sulphide stimulated the activities of the immobilised endoglucanases, but inhibited activities of the soluble enzymes above 200 mg/l. The enzyme fraction did not hydrolyse avicel (a crystalline substrate), indicating the absence of any exocellulase activity. For CMC (carboxymethylcellulose) and HEC (hydroxylethylcellulose) the enzyme had K_m,app_ values of 4 and 5.1 mg/ml respectively and V_max,app_ values of 0.297 and 0.185 μmol/min/ml respectively. Divalent ions (Cu²⁺, Ni²⁺ and Zn²⁺) proved to be inhibitory while Fe²⁺, Mg²⁺ and Ca²⁺ stimulated the enzyme at concentrations between 200 and 1000 mg/l. All the volatile fatty acids studied (acetic acid, butyric acid, propionic acid and valeric acid) inhibited the enzymes, with acetic acid eliciting the highest degree of inhibition. Sonication released ~74.9 % of the total enzyme activities into solution and this was partially purified by PEG 20 000 concentration followed by DEAE-Cellulose ion exchange chromatography, which resulted in an appreciable purity as measured by the purification factor, 25.4 fold.
- Full Text:
The experiences and needs of HIV/AIDS counsellors at Settlers Hospital, Grahamstown
- Authors: Nulty, Maria
- Date: 2004
- Subjects: AIDS (Disease) -- Patients -- Counseling of -- South Africa -- Eastern Cape HIV-positive persons -- Counseling of -- South Africa -- Eastern Cape Counselors -- South Africa -- Eastern Cape Counselors -- Supervision of -- South Africa -- Eastern Cape Counselors -- Training of -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3032 , http://hdl.handle.net/10962/d1002541
- Description: Cognisant of the fact that counselling has become an essential aspect of dealing with HIV/AIDS in South Africa, the researcher aimed to explore the stressors experienced by HIV/AIDS counsellors. It was envisioned that the results obtained would both help to improve the counselling services provided at Settlers Hospital, and assist other organisations to do so. The research focused on how the participants dealt with the dual roles of non-directive listening and the more prescriptive advice-giving, the stressors they experienced and the support structures they had, or needed, to assist them in being more effective HIV/AIDS counsellors. The sample consisted of four HIV/AIDS counsellors working at Settlers Hospital, Grahamstown. The co-ordinator of HIV/AIDS at the hospital was interviewed for collateral information. A qualitative, multiple case study was undertaken. In-depth, semi-structured interviews were used to collect the data which were recorded and transcribed and then constructed into coherently organised personal narratives of each participant’s experiences. A composite description of all the results was arrived at through the use of a reading guide which reduced the data into a thematic content analysis. The analysed data served to present an understanding of the counsellors’ experiences and to enable recommendations to be made which could assist them in pursuing their work more effectively. The findings of this study indicate that HIV/AIDS counselling is an emotionally stressful occupation. Contributory factors include the twofold role of promoting prevention and serving as empathic listeners. Other stressors derive from issues of confidentiality and stigma concerning HIV/AIDS, counsellors’ identification with clients’ experiences and the demographics of HIV/AIDS in South Africa. Situational stressors which arise from working as both nurses and counsellors in a public health institution were also identified. Recommendations are made to alleviate the counsellors’ stress in the form of facilitated emotional support groups, professional supervision, managerial support to improve the working environment, and ongoing in-service training.
- Full Text:
- Authors: Nulty, Maria
- Date: 2004
- Subjects: AIDS (Disease) -- Patients -- Counseling of -- South Africa -- Eastern Cape HIV-positive persons -- Counseling of -- South Africa -- Eastern Cape Counselors -- South Africa -- Eastern Cape Counselors -- Supervision of -- South Africa -- Eastern Cape Counselors -- Training of -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3032 , http://hdl.handle.net/10962/d1002541
- Description: Cognisant of the fact that counselling has become an essential aspect of dealing with HIV/AIDS in South Africa, the researcher aimed to explore the stressors experienced by HIV/AIDS counsellors. It was envisioned that the results obtained would both help to improve the counselling services provided at Settlers Hospital, and assist other organisations to do so. The research focused on how the participants dealt with the dual roles of non-directive listening and the more prescriptive advice-giving, the stressors they experienced and the support structures they had, or needed, to assist them in being more effective HIV/AIDS counsellors. The sample consisted of four HIV/AIDS counsellors working at Settlers Hospital, Grahamstown. The co-ordinator of HIV/AIDS at the hospital was interviewed for collateral information. A qualitative, multiple case study was undertaken. In-depth, semi-structured interviews were used to collect the data which were recorded and transcribed and then constructed into coherently organised personal narratives of each participant’s experiences. A composite description of all the results was arrived at through the use of a reading guide which reduced the data into a thematic content analysis. The analysed data served to present an understanding of the counsellors’ experiences and to enable recommendations to be made which could assist them in pursuing their work more effectively. The findings of this study indicate that HIV/AIDS counselling is an emotionally stressful occupation. Contributory factors include the twofold role of promoting prevention and serving as empathic listeners. Other stressors derive from issues of confidentiality and stigma concerning HIV/AIDS, counsellors’ identification with clients’ experiences and the demographics of HIV/AIDS in South Africa. Situational stressors which arise from working as both nurses and counsellors in a public health institution were also identified. Recommendations are made to alleviate the counsellors’ stress in the form of facilitated emotional support groups, professional supervision, managerial support to improve the working environment, and ongoing in-service training.
- Full Text:
The feeding biology and potential impact of introduced giraffe (Giraffa camelopardalis) in the Eastern Cape Province, South Africa
- Authors: Parker, Daniel Matthew
- Date: 2004
- Subjects: Giraffe -- South Africa -- Eastern Cape , Animal-plant relationships -- South Africa -- Eastern Cape , Giraffe -- Food -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5694 , http://hdl.handle.net/10962/d1005380
- Description: Giraffe (Giraffa camelopardalis) are extralimital (non-native) to the Eastern Cape Province, South Africa yet they have and continue to be introduced to the region. Financial gain has arguably been the driving force behind these introductions as foreign tourists associate giraffe with Africa and the African wildlife experience. This raises a number of ethical, ecological and philosophical questions especially when it is considered that the impact of these browsers on the indigenous vegetation has remained largely unquantified. In this study I assessed the diet and potential impact of three populations of giraffe in the Eastern Cape Province between January 2002 and October 2003. The diet was assessed by both direct observations and faecal analysis. There was no significant difference (P > 0.05) between the results of the two methods of analysis, although direct observations appeared to be a superior method for assessing the diet of giraffe. The diet of giraffe in the Eastern Cape Province was similar to that within their native range with a deciduous species from the genus Acacia (Acacia karroo) being the most important component of the diet. However, giraffe in the Eastern Cape Province consumed more evergreen plant species than those within their native range. The relative lack of deciduous species in the Eastern Cape Province provides a likely explanation for such a result. Seasonal variation in the consumption of the most important species in the diet was evident and this was attributed to the deciduous nature of A. karroo and the seasonal growth of new shoots which were more palatable. The vegetation of the areas most commonly utilised by giraffe at each site was sampled using the point-centred-quarter method and the results related to the frequency of each species in the diet to calculate preference indices. Giraffe preference was strongest for A. karroo and this was attributed to the highly favourable chemical composition of the species. The browse utilisation of giraffe at each site was determined using the twig-length method and intake rates for the three most important species in the diet calculated using a pre-existing regression equation. Male giraffe fed at a higher rate than females. This was probably due to males adopting a “time-minimising” strategy to their feeding in order to allow more time for reproductive pursuits. Giraffe browse utilisation was highest where giraffe density was highest. However, several species were more heavily browsed than others even when giraffe density was low, suggesting that giraffe are capable of negatively affecting the indigenous flora of the province. I conclude that giraffe numbers should be reduced relative to property size in the Eastern Cape Province and that research into the impact of not only giraffe but the combined effects of giraffe and other extralimital herbivores on the indigenous flora and fauna be continued.
- Full Text:
- Authors: Parker, Daniel Matthew
- Date: 2004
- Subjects: Giraffe -- South Africa -- Eastern Cape , Animal-plant relationships -- South Africa -- Eastern Cape , Giraffe -- Food -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5694 , http://hdl.handle.net/10962/d1005380
- Description: Giraffe (Giraffa camelopardalis) are extralimital (non-native) to the Eastern Cape Province, South Africa yet they have and continue to be introduced to the region. Financial gain has arguably been the driving force behind these introductions as foreign tourists associate giraffe with Africa and the African wildlife experience. This raises a number of ethical, ecological and philosophical questions especially when it is considered that the impact of these browsers on the indigenous vegetation has remained largely unquantified. In this study I assessed the diet and potential impact of three populations of giraffe in the Eastern Cape Province between January 2002 and October 2003. The diet was assessed by both direct observations and faecal analysis. There was no significant difference (P > 0.05) between the results of the two methods of analysis, although direct observations appeared to be a superior method for assessing the diet of giraffe. The diet of giraffe in the Eastern Cape Province was similar to that within their native range with a deciduous species from the genus Acacia (Acacia karroo) being the most important component of the diet. However, giraffe in the Eastern Cape Province consumed more evergreen plant species than those within their native range. The relative lack of deciduous species in the Eastern Cape Province provides a likely explanation for such a result. Seasonal variation in the consumption of the most important species in the diet was evident and this was attributed to the deciduous nature of A. karroo and the seasonal growth of new shoots which were more palatable. The vegetation of the areas most commonly utilised by giraffe at each site was sampled using the point-centred-quarter method and the results related to the frequency of each species in the diet to calculate preference indices. Giraffe preference was strongest for A. karroo and this was attributed to the highly favourable chemical composition of the species. The browse utilisation of giraffe at each site was determined using the twig-length method and intake rates for the three most important species in the diet calculated using a pre-existing regression equation. Male giraffe fed at a higher rate than females. This was probably due to males adopting a “time-minimising” strategy to their feeding in order to allow more time for reproductive pursuits. Giraffe browse utilisation was highest where giraffe density was highest. However, several species were more heavily browsed than others even when giraffe density was low, suggesting that giraffe are capable of negatively affecting the indigenous flora of the province. I conclude that giraffe numbers should be reduced relative to property size in the Eastern Cape Province and that research into the impact of not only giraffe but the combined effects of giraffe and other extralimital herbivores on the indigenous flora and fauna be continued.
- Full Text:
The fuelwood crisis in southern Africa: Relating fuelwood use to livelihoods in a rural village
- Dovie, Delali B K, Witkowski, Ed T F, Shackleton, Charlie M
- Authors: Dovie, Delali B K , Witkowski, Ed T F , Shackleton, Charlie M
- Date: 2004
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/181402 , vital:43730 , xlink:href="https://doi.org/10.1023/B:GEJO.0000033597.34013.9f"
- Description: The aim of the paper is to examine wood as a source of fuel energy in rural South Africa and factors influencing its usage. The analysis is based on household profiles and characteristics (e.g., gender, caste, population and income) in a livelihood framework. Fuelwood consumption was estimated to be 692 kg/capita, and 4343 kg/user household per annum, valued at $311 per household. Consumption was modelled in relation to informal and formal cash incomes, and population of children, female and male adults. However, only the population of female adults could significantly influence consumption of fuelwood. This implied that where there were more women in a household, consumption was likely to be high. This might be due to the majority of women doing the cooking and heating in the household. Any change in the value of cash income of households had no significant impacts on fuelwood consumed. Cash incomes might therefore not be strong determinants of the types of energy used by rural households. The average quantity of wood consumed for fuel energy in summer was not significantly different from consumption in winter. Some households perpetually used more wood than others. The study further showed that harvesting of wood for fuel energy is not opportunistic, but requires reallocation of time for other livelihood activities in times of shortage. The fuelwood crisis is not simple and not only about shortage of fuelwood and/or population growth but linked to household profiles and other livelihood strategies and subsequently vulnerability of households. These would require thorough investigation and understanding in relation to precise demand and supply data for fuelwood before the fuelwood problem can be sufficiently managed.
- Full Text:
- Authors: Dovie, Delali B K , Witkowski, Ed T F , Shackleton, Charlie M
- Date: 2004
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/181402 , vital:43730 , xlink:href="https://doi.org/10.1023/B:GEJO.0000033597.34013.9f"
- Description: The aim of the paper is to examine wood as a source of fuel energy in rural South Africa and factors influencing its usage. The analysis is based on household profiles and characteristics (e.g., gender, caste, population and income) in a livelihood framework. Fuelwood consumption was estimated to be 692 kg/capita, and 4343 kg/user household per annum, valued at $311 per household. Consumption was modelled in relation to informal and formal cash incomes, and population of children, female and male adults. However, only the population of female adults could significantly influence consumption of fuelwood. This implied that where there were more women in a household, consumption was likely to be high. This might be due to the majority of women doing the cooking and heating in the household. Any change in the value of cash income of households had no significant impacts on fuelwood consumed. Cash incomes might therefore not be strong determinants of the types of energy used by rural households. The average quantity of wood consumed for fuel energy in summer was not significantly different from consumption in winter. Some households perpetually used more wood than others. The study further showed that harvesting of wood for fuel energy is not opportunistic, but requires reallocation of time for other livelihood activities in times of shortage. The fuelwood crisis is not simple and not only about shortage of fuelwood and/or population growth but linked to household profiles and other livelihood strategies and subsequently vulnerability of households. These would require thorough investigation and understanding in relation to precise demand and supply data for fuelwood before the fuelwood problem can be sufficiently managed.
- Full Text:
The general election in Lesotho, May 2002: adapting to MMP
- Fox, Roddy C, Southall, Roger J
- Authors: Fox, Roddy C , Southall, Roger J
- Date: 2004
- Language: English
- Type: Article
- Identifier: vital:6680 , http://hdl.handle.net/10962/d1006673
- Description: Voters in the small southern African kingdom of Lesotho went to the polls on 25 May 2002, in the third general election since the country returned to democracy following a long period of civilian dictatorship (1970–1986) and military rule (1986–1993). Voting in all Lesotho’s general elections has usually gone smoothly, yet in every case prior to 2002 the results have been challenged, with varying severity, by the losing parties (Weisfelder, 1999). This occurred most notably in 1970, when the ruling Basotho National Party (BNP) lost the election but overrode the result, and subsequently in 1998, when the BNP—then in opposition—was at the core of an alliance of electoral losers; in the months that followed, and with the quiet support of the security forces, the capital was so paralysed that the government called for external assistance to restore order. The result was military intervention by South Africa and Botswana (who acted on behalf of the Southern African Development Community, SADC), the restoration of power to the Lesotho Congress for Democracy (LCD), and an extended period when, backed by South African muscle, long overdue reforms of the military and police were implemented. These reforms were matched by negotiations between the parties about adopting a new electoral system. The outcome moved Lesotho away from the first-past-the-post system inherited from Britain at independence (which in 1993 and 1998 had resulted in highly imbalanced results favouring the winning party) towards a Mixed Member Proportional (MMP) system. Lesotho became the first country in Africa to adopt MMP at a time when discussion of electoral system change was becoming widespread throughout the continent. The issue in Lesotho in 2002 was not merely whether MMP would provide greater electoral legitimacy and political stability; subsequent events have provided a resounding ‘Yes’ (Elklit, 2002 and Southall, 2003). But there were questions about the practicality of the new system and whether voters would understand it. Was it possible to explain a new voting system to an electorate in one of Africa’s poorest countries? The main focus of this Note is to demonstrate that voters can adapt to electoral system change. Thus, it throws doubt on arguments that electoral reforms in Africa should be avoided due to a lack of sophistication among poor and largely uneducated voters. Electors in Lesotho appeared to have no great difficulty in understanding the broad principles of the new electoral system, even if the detailed mechanics of ‘mixed’ voting systems may have been beyond them.
- Full Text:
- Authors: Fox, Roddy C , Southall, Roger J
- Date: 2004
- Language: English
- Type: Article
- Identifier: vital:6680 , http://hdl.handle.net/10962/d1006673
- Description: Voters in the small southern African kingdom of Lesotho went to the polls on 25 May 2002, in the third general election since the country returned to democracy following a long period of civilian dictatorship (1970–1986) and military rule (1986–1993). Voting in all Lesotho’s general elections has usually gone smoothly, yet in every case prior to 2002 the results have been challenged, with varying severity, by the losing parties (Weisfelder, 1999). This occurred most notably in 1970, when the ruling Basotho National Party (BNP) lost the election but overrode the result, and subsequently in 1998, when the BNP—then in opposition—was at the core of an alliance of electoral losers; in the months that followed, and with the quiet support of the security forces, the capital was so paralysed that the government called for external assistance to restore order. The result was military intervention by South Africa and Botswana (who acted on behalf of the Southern African Development Community, SADC), the restoration of power to the Lesotho Congress for Democracy (LCD), and an extended period when, backed by South African muscle, long overdue reforms of the military and police were implemented. These reforms were matched by negotiations between the parties about adopting a new electoral system. The outcome moved Lesotho away from the first-past-the-post system inherited from Britain at independence (which in 1993 and 1998 had resulted in highly imbalanced results favouring the winning party) towards a Mixed Member Proportional (MMP) system. Lesotho became the first country in Africa to adopt MMP at a time when discussion of electoral system change was becoming widespread throughout the continent. The issue in Lesotho in 2002 was not merely whether MMP would provide greater electoral legitimacy and political stability; subsequent events have provided a resounding ‘Yes’ (Elklit, 2002 and Southall, 2003). But there were questions about the practicality of the new system and whether voters would understand it. Was it possible to explain a new voting system to an electorate in one of Africa’s poorest countries? The main focus of this Note is to demonstrate that voters can adapt to electoral system change. Thus, it throws doubt on arguments that electoral reforms in Africa should be avoided due to a lack of sophistication among poor and largely uneducated voters. Electors in Lesotho appeared to have no great difficulty in understanding the broad principles of the new electoral system, even if the detailed mechanics of ‘mixed’ voting systems may have been beyond them.
- Full Text:
The geology of the Proterozoic Haveri Au-Cu deposit, Southern Finland
- Strauss, Toby Anthony Lavery
- Authors: Strauss, Toby Anthony Lavery
- Date: 2004
- Subjects: Geology, Stratigraphic -- Precambrian , Geology, Stratigraphic -- Proterozoic , Ore deposits -- Finland , Geology -- Finland
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5081 , http://hdl.handle.net/10962/d1015978
- Description: The Haveri Au-Cu deposit is located in southern Finland about 175 km north of Helsinki. It occurs on the northern edge of the continental island arc-type, volcano-sedimentary Tampere Schist Belt (TSB) within the Palaeoproterozoic Svecofennian Domain (2.0 – 1.75 Ga) of the Fennoscandian Shield. The 1.99 Ga Haveri Formation forms the base of the supracrustal stratigraphy consisting of metavolcanic pillow lavas and breccias passing upwards into intercalated metatuffs and metatuffites. There is a continuous gradation upwards from the predominantly volcaniclastic Haveri Formation into the overlying epiclastic meta-greywackes of the Osara Formation. The Haveri deposit is hosted in this contact zone. This supracrustal sequence has been intruded concordantly by quartz-feldspar porphyries. Approximately 1.89 Ga ago, high crustal heat flow led to the generation and emplacement of voluminous synkinematic, I-type, magnetite-series granitoids of the Central Finland Granitoid Complex (CFGC), resulting in coeval high-T/low-P metamorphism (hornfelsic textures), and D₁ deformation. During the crystallisation and cooling of the granitoids, a magmatic-dominated hydrothermal system caused extensive hydrothermal alteration and Cu-Au mineralisation through the late-D₁ to early-D₂ deformation. Initially, a pre-ore Na-Ca alteration phase caused albitisation of the host rock. This was closely followed by strong Ca-Fe alteration, responsible for widespread amphibolitisation and quartz veining and associated with abundant pyrrhotite, magnetite, chalcopyrite and gold mineralisation. More localised calcic-skarn alteration is also present as zoned garnetpyroxene- epidote skarn assemblages with associated pyrrhotite and minor sphalerite, centred on quartzcalcite± scapolite veinlets. Post-ore alteration includes an evolution to more K-rich alteration (biotitisation). Late D₂-retrograde chlorite began to replace the earlier high-T assemblage. Late emanations (post-D₂ and pre-D₃) from the cooling granitoids, under lower temperatures and oxidising conditions, are represented by carbonate-barite veins and epidote veinlets. Later, narrow dolerite dykes were emplaced followed by a weak D₃ deformation, resulting in shearing and structural reactivation along the carbonate-barite bands. This phase was accompanied by pyrite deposition. Both sulphides and oxides are common at Haveri, with ore types varying from massive sulphide and/or magnetite, to networks of veinlets and disseminations of oxides and/or sulphides. Cataclastites, consisting of deformed, brecciated bands of sulphide, with rounded and angular clasts of quartz vein material and altered host-rock are an economically important ore type. Ore minerals are principally pyrrhotite, magnetite and chalcopyrite with lesser amounts of pyrite, molybdenite and sphalerite. There is a general progression from early magnetite, through pyrrhotite to pyrite indicating increasing sulphidation with time. Gold is typically found as free gold within quartz veins and within intense zones of amphibolitisation. Considerable gold is also found in the cataclastite ore type either as invisible gold within the sulphides and/or as free gold within the breccia fragments. The unaltered amphibolites of the Haveri Formation can be classified as medium-K basalts of the tholeiitic trend. Trace and REE support an interpretation of formation in a back-arc basin setting. The unaltered porphyritic rocks are calc-alkaline dacites, and are interpreted, along with the granitoids as having an arc-type origin. This is consistent with the evolution from an initial back-arc basin, through a period of passive margin and/or fore-arc deposition represented by the Osara Formation greywackes and the basal stratigraphy of the TSB, prior to the onset of arc-related volcanic activity characteristic of the TSB and the Svecofennian proper. Using a combination of petrogenetic grids, mineral compositions (garnet-biotite and hornblendeplagioclase thermometers) and oxygen isotope thermometry, peak metamorphism can be constrained to a maximum of approximately 600 °C and 1.5 kbars pressure. Furthermore, the petrogenetic grids indicate that the REDOX conditions can be constrained at 600°C to log f(O₂) values of approximately - 21.0 to -26.0 and -14.5 to -17.5 for the metasedimentary rocks and mafic metavolcanic rocks respectively, thus indicating the presence of a significant REDOX boundary. Amphibole compositions from the Ca-Fe alteration phase (amphibolitisation) indicate iron enrichment with increasing alteration corresponding to higher temperatures of formation. Oxygen isotope studies combined with limited fluid inclusion studies indicate that the Ca-Fe alteration and associated quartz veins formed at high temperatures (530 – 610°C) from low CO₂, low- to moderately saline (<10 eq. wt% NaCl), magmatic-dominated fluids. Fluid inclusion decrepitation textures in the quartz veins suggest isobaric decompression. This is compatible with formation in high-T/low-P environments such as contact aureoles and island arcs. The calcic-skarn assemblage, combined with phase equilibria and sphalerite geothermometry, are indicative of formation at high temperatures (500 – 600 °C) from fluids with higher CO₂ contents and more saline compositions than those responsible for the Fe-Ca alteration. Limited fluid inclusion studies have identified hypersaline inclusions in secondary inclusion trails within quartz. The presence of calcite and scapolite also support formation from CO₂-rich saline fluids. It is suggested that the calcic-skarn alteration and the amphibolitisation evolved from the same fluids, and that P-T changes led to fluid unmixing resulting in two fluid types responsible for the observed alteration variations. Chlorite geothermometry on retrograde chlorite indicates temperatures of 309 – 368 °C. As chlorite represents the latest hydrothermal event, this can be taken as a lower temperature limit for hydrothermal alteration and mineralisation at Haveri.The gold mineralisation at Haveri is related primarily to the Ca-Fe alteration. Under such P-T-X conditions gold was transported as chloride complexes. Ore was localised by a combination of structural controls (shears and folds) and REDOX reactions along the boundary between the oxidised metavolcanics and the reduced metasediments. In addition, fluid unmixing caused an increase in pH, and thus further augmented the precipitation of Cu and Au. During the late D₂-event, temperatures fell below 400 °C, and fluids may have remobilised Au and Cu as bisulphide complexes into the shearcontrolled cataclastites and massive sulphides. The Haveri deposit has many similarities with ore deposit models that include orogenic lode-gold deposits, certain Au-skarn deposits and Fe-oxide Cu-Au deposits. However, many characteristics of the Haveri deposit, including tectonic setting, host lithologies, alteration types, proximity to I-type granitoids and P-T-X conditions of formation, compare favourably with other Early Proterozoic deposits within the TSB and Fennoscandia, as well as many of the deposits in the Cloncurry district of Australia. Consequently, the Haveri deposit can be seen to represent a high-T, Ca-rich member of the recently recognised Fe-oxide Cu-Au group of deposits.
- Full Text:
- Authors: Strauss, Toby Anthony Lavery
- Date: 2004
- Subjects: Geology, Stratigraphic -- Precambrian , Geology, Stratigraphic -- Proterozoic , Ore deposits -- Finland , Geology -- Finland
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5081 , http://hdl.handle.net/10962/d1015978
- Description: The Haveri Au-Cu deposit is located in southern Finland about 175 km north of Helsinki. It occurs on the northern edge of the continental island arc-type, volcano-sedimentary Tampere Schist Belt (TSB) within the Palaeoproterozoic Svecofennian Domain (2.0 – 1.75 Ga) of the Fennoscandian Shield. The 1.99 Ga Haveri Formation forms the base of the supracrustal stratigraphy consisting of metavolcanic pillow lavas and breccias passing upwards into intercalated metatuffs and metatuffites. There is a continuous gradation upwards from the predominantly volcaniclastic Haveri Formation into the overlying epiclastic meta-greywackes of the Osara Formation. The Haveri deposit is hosted in this contact zone. This supracrustal sequence has been intruded concordantly by quartz-feldspar porphyries. Approximately 1.89 Ga ago, high crustal heat flow led to the generation and emplacement of voluminous synkinematic, I-type, magnetite-series granitoids of the Central Finland Granitoid Complex (CFGC), resulting in coeval high-T/low-P metamorphism (hornfelsic textures), and D₁ deformation. During the crystallisation and cooling of the granitoids, a magmatic-dominated hydrothermal system caused extensive hydrothermal alteration and Cu-Au mineralisation through the late-D₁ to early-D₂ deformation. Initially, a pre-ore Na-Ca alteration phase caused albitisation of the host rock. This was closely followed by strong Ca-Fe alteration, responsible for widespread amphibolitisation and quartz veining and associated with abundant pyrrhotite, magnetite, chalcopyrite and gold mineralisation. More localised calcic-skarn alteration is also present as zoned garnetpyroxene- epidote skarn assemblages with associated pyrrhotite and minor sphalerite, centred on quartzcalcite± scapolite veinlets. Post-ore alteration includes an evolution to more K-rich alteration (biotitisation). Late D₂-retrograde chlorite began to replace the earlier high-T assemblage. Late emanations (post-D₂ and pre-D₃) from the cooling granitoids, under lower temperatures and oxidising conditions, are represented by carbonate-barite veins and epidote veinlets. Later, narrow dolerite dykes were emplaced followed by a weak D₃ deformation, resulting in shearing and structural reactivation along the carbonate-barite bands. This phase was accompanied by pyrite deposition. Both sulphides and oxides are common at Haveri, with ore types varying from massive sulphide and/or magnetite, to networks of veinlets and disseminations of oxides and/or sulphides. Cataclastites, consisting of deformed, brecciated bands of sulphide, with rounded and angular clasts of quartz vein material and altered host-rock are an economically important ore type. Ore minerals are principally pyrrhotite, magnetite and chalcopyrite with lesser amounts of pyrite, molybdenite and sphalerite. There is a general progression from early magnetite, through pyrrhotite to pyrite indicating increasing sulphidation with time. Gold is typically found as free gold within quartz veins and within intense zones of amphibolitisation. Considerable gold is also found in the cataclastite ore type either as invisible gold within the sulphides and/or as free gold within the breccia fragments. The unaltered amphibolites of the Haveri Formation can be classified as medium-K basalts of the tholeiitic trend. Trace and REE support an interpretation of formation in a back-arc basin setting. The unaltered porphyritic rocks are calc-alkaline dacites, and are interpreted, along with the granitoids as having an arc-type origin. This is consistent with the evolution from an initial back-arc basin, through a period of passive margin and/or fore-arc deposition represented by the Osara Formation greywackes and the basal stratigraphy of the TSB, prior to the onset of arc-related volcanic activity characteristic of the TSB and the Svecofennian proper. Using a combination of petrogenetic grids, mineral compositions (garnet-biotite and hornblendeplagioclase thermometers) and oxygen isotope thermometry, peak metamorphism can be constrained to a maximum of approximately 600 °C and 1.5 kbars pressure. Furthermore, the petrogenetic grids indicate that the REDOX conditions can be constrained at 600°C to log f(O₂) values of approximately - 21.0 to -26.0 and -14.5 to -17.5 for the metasedimentary rocks and mafic metavolcanic rocks respectively, thus indicating the presence of a significant REDOX boundary. Amphibole compositions from the Ca-Fe alteration phase (amphibolitisation) indicate iron enrichment with increasing alteration corresponding to higher temperatures of formation. Oxygen isotope studies combined with limited fluid inclusion studies indicate that the Ca-Fe alteration and associated quartz veins formed at high temperatures (530 – 610°C) from low CO₂, low- to moderately saline (<10 eq. wt% NaCl), magmatic-dominated fluids. Fluid inclusion decrepitation textures in the quartz veins suggest isobaric decompression. This is compatible with formation in high-T/low-P environments such as contact aureoles and island arcs. The calcic-skarn assemblage, combined with phase equilibria and sphalerite geothermometry, are indicative of formation at high temperatures (500 – 600 °C) from fluids with higher CO₂ contents and more saline compositions than those responsible for the Fe-Ca alteration. Limited fluid inclusion studies have identified hypersaline inclusions in secondary inclusion trails within quartz. The presence of calcite and scapolite also support formation from CO₂-rich saline fluids. It is suggested that the calcic-skarn alteration and the amphibolitisation evolved from the same fluids, and that P-T changes led to fluid unmixing resulting in two fluid types responsible for the observed alteration variations. Chlorite geothermometry on retrograde chlorite indicates temperatures of 309 – 368 °C. As chlorite represents the latest hydrothermal event, this can be taken as a lower temperature limit for hydrothermal alteration and mineralisation at Haveri.The gold mineralisation at Haveri is related primarily to the Ca-Fe alteration. Under such P-T-X conditions gold was transported as chloride complexes. Ore was localised by a combination of structural controls (shears and folds) and REDOX reactions along the boundary between the oxidised metavolcanics and the reduced metasediments. In addition, fluid unmixing caused an increase in pH, and thus further augmented the precipitation of Cu and Au. During the late D₂-event, temperatures fell below 400 °C, and fluids may have remobilised Au and Cu as bisulphide complexes into the shearcontrolled cataclastites and massive sulphides. The Haveri deposit has many similarities with ore deposit models that include orogenic lode-gold deposits, certain Au-skarn deposits and Fe-oxide Cu-Au deposits. However, many characteristics of the Haveri deposit, including tectonic setting, host lithologies, alteration types, proximity to I-type granitoids and P-T-X conditions of formation, compare favourably with other Early Proterozoic deposits within the TSB and Fennoscandia, as well as many of the deposits in the Cloncurry district of Australia. Consequently, the Haveri deposit can be seen to represent a high-T, Ca-rich member of the recently recognised Fe-oxide Cu-Au group of deposits.
- Full Text:
The Harry Potter phenomenon literary production, generic traditions, and the question of values
- Authors: Glover, Jayne Ashleigh
- Date: 2004
- Subjects: Rowling, J. K. Criticism and interpretation , Potter, Harry (Fictitious character) , Children's literature -- History and criticism , Fantasy fiction, English -- History and criticism , Wizards in literature
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2201 , http://hdl.handle.net/10962/d1002243 , Rowling, J. K. Criticism and interpretation , Potter, Harry (Fictitious character) , Children's literature -- History and criticism , Fantasy fiction, English -- History and criticism , Wizards in literature
- Description: This thesis is a study of the first four books of J. K. Rowling’s Harry Potter series. It accounts for the widespread success of the novels by examining their publication and marketing histories, and their literary achievement as narratives including a sophisticated mix of generic traditions. Chapter One looks at the popularity of the novels, comparing their material production and marketing by Rowling’s English language publishers: Bloomsbury in Britain and Scholastic in the United States of America. The publisher’s influence on the public perception of each book is demonstrated by comparative study of its mode of illustration and layout. Further, the design of the books is linked to their strategic marketing and branding within the literary world. The second chapter considers Rowling’s debt to the school story. It concentrates first on the history of this relatively short-lived genre, briefly discussing its stereotypical features and values. Traditional elements of setting and characterisation are then examined to show how the Harry Potter novels present a value system which, though apparently old-fashioned, still has an ethical standpoint designed to appeal to the modern reader. Chapter Three focuses on the characterisation of Harry as a hero-figure, especially on how the influence of classical and medieval texts infuses Rowling’s portrayal of Harry as a hero in the chivalric mode. The episodes of “quest” and “test” in each book illustrate specifically how he learns the values of selflessness, loyalty, mercy and fairness. Chapter Four surveys the contribution of modern fantasy writing to the series. It shows how Rowling creates a secondary world that allows us to perceive magic as a metaphorical representation of power. This focus on the relationship between magic and power in turn has a bearing on our assessment of the author’s moral stance. The thesis concludes by suggesting that Rowling’s unusual mix of genres is justified by the values they share, and which are inscribed in her work: the generic combination forms a workable, new and exciting mode of writing that helps to account for the phenomenal popularity of the series.
- Full Text:
- Authors: Glover, Jayne Ashleigh
- Date: 2004
- Subjects: Rowling, J. K. Criticism and interpretation , Potter, Harry (Fictitious character) , Children's literature -- History and criticism , Fantasy fiction, English -- History and criticism , Wizards in literature
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2201 , http://hdl.handle.net/10962/d1002243 , Rowling, J. K. Criticism and interpretation , Potter, Harry (Fictitious character) , Children's literature -- History and criticism , Fantasy fiction, English -- History and criticism , Wizards in literature
- Description: This thesis is a study of the first four books of J. K. Rowling’s Harry Potter series. It accounts for the widespread success of the novels by examining their publication and marketing histories, and their literary achievement as narratives including a sophisticated mix of generic traditions. Chapter One looks at the popularity of the novels, comparing their material production and marketing by Rowling’s English language publishers: Bloomsbury in Britain and Scholastic in the United States of America. The publisher’s influence on the public perception of each book is demonstrated by comparative study of its mode of illustration and layout. Further, the design of the books is linked to their strategic marketing and branding within the literary world. The second chapter considers Rowling’s debt to the school story. It concentrates first on the history of this relatively short-lived genre, briefly discussing its stereotypical features and values. Traditional elements of setting and characterisation are then examined to show how the Harry Potter novels present a value system which, though apparently old-fashioned, still has an ethical standpoint designed to appeal to the modern reader. Chapter Three focuses on the characterisation of Harry as a hero-figure, especially on how the influence of classical and medieval texts infuses Rowling’s portrayal of Harry as a hero in the chivalric mode. The episodes of “quest” and “test” in each book illustrate specifically how he learns the values of selflessness, loyalty, mercy and fairness. Chapter Four surveys the contribution of modern fantasy writing to the series. It shows how Rowling creates a secondary world that allows us to perceive magic as a metaphorical representation of power. This focus on the relationship between magic and power in turn has a bearing on our assessment of the author’s moral stance. The thesis concludes by suggesting that Rowling’s unusual mix of genres is justified by the values they share, and which are inscribed in her work: the generic combination forms a workable, new and exciting mode of writing that helps to account for the phenomenal popularity of the series.
- Full Text:
The impact of commercial harvesting on Warburgia salutaris (‘pepper-bark tree’) in Mpumalanga, South Africa
- Botha, Jenny, Witkowski, Ed T F, Shackleton, Charlie M
- Authors: Botha, Jenny , Witkowski, Ed T F , Shackleton, Charlie M
- Date: 2004
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/181391 , vital:43729 , xlink:href="https://doi.org/10.1023/B:BIOC.0000029333.72945.b0"
- Description: Commercialisation often increases the difficulty in managing harvested plant populations sustainably. The bark of the popular medicinal species, Warburgia salutaris (Bertol.f.) Chiov. (Canellaceae) (‘pepper-bark tree’), is widely traded throughout southern Africa. The impact of commercial harvesting on this Red Data species was assessed by comparing commercially harvested populations with populations growing on private land or in protected areas (termed ‘protected populations’) in Mpumalanga and Limpopo Province, South Africa. The basal diameters and heights of stems in commercially harvested populations were significantly lower than those of the protected populations. The density of young/small plants was low in all populations. W. salutaris is usually resilient to high levels of bark harvesting. In this study, 75% of heavily harvested stems (>10% of the stem below 2 m) coppiced (resprouted). However, individuals that had been affected by regular fires, or repeatedly harvested, appeared prone to a fungal disease and had high percentage mortality. The populations occurring on private land appeared the most vigorous. Habitat in one protected area had been reduced through the construction of a dam. In another, small W. salutaris populations exhibited a shrubby growth form, probably due to frequent fires. Our current knowledge for this species supports a global IUCN status of EN A4acd. Plant conservation needs to become a higher priority both within and outside protected areas. Commercially harvested populations should be better managed through improved harvesting techniques and monitoring. Cultivation levels urgently need to be increased. Further research should be conducted on factors limiting regeneration, including the most appropriate fire regime.
- Full Text:
- Authors: Botha, Jenny , Witkowski, Ed T F , Shackleton, Charlie M
- Date: 2004
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/181391 , vital:43729 , xlink:href="https://doi.org/10.1023/B:BIOC.0000029333.72945.b0"
- Description: Commercialisation often increases the difficulty in managing harvested plant populations sustainably. The bark of the popular medicinal species, Warburgia salutaris (Bertol.f.) Chiov. (Canellaceae) (‘pepper-bark tree’), is widely traded throughout southern Africa. The impact of commercial harvesting on this Red Data species was assessed by comparing commercially harvested populations with populations growing on private land or in protected areas (termed ‘protected populations’) in Mpumalanga and Limpopo Province, South Africa. The basal diameters and heights of stems in commercially harvested populations were significantly lower than those of the protected populations. The density of young/small plants was low in all populations. W. salutaris is usually resilient to high levels of bark harvesting. In this study, 75% of heavily harvested stems (>10% of the stem below 2 m) coppiced (resprouted). However, individuals that had been affected by regular fires, or repeatedly harvested, appeared prone to a fungal disease and had high percentage mortality. The populations occurring on private land appeared the most vigorous. Habitat in one protected area had been reduced through the construction of a dam. In another, small W. salutaris populations exhibited a shrubby growth form, probably due to frequent fires. Our current knowledge for this species supports a global IUCN status of EN A4acd. Plant conservation needs to become a higher priority both within and outside protected areas. Commercially harvested populations should be better managed through improved harvesting techniques and monitoring. Cultivation levels urgently need to be increased. Further research should be conducted on factors limiting regeneration, including the most appropriate fire regime.
- Full Text:
The impact of smart cards on South African rural pensioners' lives
- Authors: Nyoka, Zanele
- Date: 2004
- Subjects: Old age pensioners -- South Africa -- Management Smart cards South African Post Office
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:818 , http://hdl.handle.net/10962/d1008052
- Description: E-commerce technologies have many possible applications both in commercial and non-commercial operations. The development and implementation of these applications is on the increase especially by government and its agencies, for the delivery of services. Specific to this study is the distribution of old age pension benefits to recipients that reside in the rural areas of South Africa. Of importance to this study are the factors that promote and impinge on the development, implementation and acceptance of these applications. A specific project, the Pension Biometric Project was implemented by the South African Post Office in line with the government's initiatives of improving service delivery, and in response to the encroaching digital economy. The research problem is to investigate the pensioners' perception and their experience of three areas of this project, its implementation, its acceptance and its uses and impact. The research was conducted in the constructivist paradigm, using the case study research method. Three data collection methods were used, i.e. a document study of SAPO project documentation, on-site observations and interviews with pensioners. It was found that despite problems in implementation, the pensioners were accepting of the new system, although they were ignorant of the functionalities of the smart card. Consequently, few pensioners were making use of the banking facilities of the card, or had changed their economic behaviour. The study has also found that two themes are overriding all findings of the study. These two themes are ignorance and dignity. Ignorance has had a causal effect on adoption of the smart cards and dignity has been found to be a result of the project. The overriding implication of this study is that pensioners' ignorance around issues of service delivery by government and its agencies needs to be eradicated, otherwise there is no reliable way of measuring efforts against actual delivery. Also, the fact that dignity has emerged as an overriding theme needs to be deliberately strengthened, and maybe even driven as a specified objective of the Pension Biometric Project. Recommendations in this regard are provided as well as ideas for further research.
- Full Text:
- Authors: Nyoka, Zanele
- Date: 2004
- Subjects: Old age pensioners -- South Africa -- Management Smart cards South African Post Office
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:818 , http://hdl.handle.net/10962/d1008052
- Description: E-commerce technologies have many possible applications both in commercial and non-commercial operations. The development and implementation of these applications is on the increase especially by government and its agencies, for the delivery of services. Specific to this study is the distribution of old age pension benefits to recipients that reside in the rural areas of South Africa. Of importance to this study are the factors that promote and impinge on the development, implementation and acceptance of these applications. A specific project, the Pension Biometric Project was implemented by the South African Post Office in line with the government's initiatives of improving service delivery, and in response to the encroaching digital economy. The research problem is to investigate the pensioners' perception and their experience of three areas of this project, its implementation, its acceptance and its uses and impact. The research was conducted in the constructivist paradigm, using the case study research method. Three data collection methods were used, i.e. a document study of SAPO project documentation, on-site observations and interviews with pensioners. It was found that despite problems in implementation, the pensioners were accepting of the new system, although they were ignorant of the functionalities of the smart card. Consequently, few pensioners were making use of the banking facilities of the card, or had changed their economic behaviour. The study has also found that two themes are overriding all findings of the study. These two themes are ignorance and dignity. Ignorance has had a causal effect on adoption of the smart cards and dignity has been found to be a result of the project. The overriding implication of this study is that pensioners' ignorance around issues of service delivery by government and its agencies needs to be eradicated, otherwise there is no reliable way of measuring efforts against actual delivery. Also, the fact that dignity has emerged as an overriding theme needs to be deliberately strengthened, and maybe even driven as a specified objective of the Pension Biometric Project. Recommendations in this regard are provided as well as ideas for further research.
- Full Text:
The implementation of multigrade teaching in rural schools in the Keetmanshoop education region: leadership and management challenges
- Authors: Titus, David Petrus
- Date: 2004
- Subjects: Education -- Namibia Education, Rural -- Namibia Education and state -- Namibia Educational change -- Namibia School management and organization -- Namibia Rural schools -- Namibia Educational leadership -- Namibia School principals -- Namibia
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1566 , http://hdl.handle.net/10962/d1003448
- Description: Leadership has received much attention in both the business world and education. My thesis explores effective educational leadership through examining the management and leadership challenges that face principals in a multi-grade school. Schools in sparsely populated rural areas in Namibia have had to resort to multi-grade teaching to be able to be economically viable. Hard economic realities force people to move to bigger towns and cities. The constant demand for better schools, effective principals, qualified teachers and an improved service to the communities coupled with the demand for better working conditions and salaries for teachers drained the education budget even further. To keep in line with the four major policies of education namely equity, access, quality and democracy, the operation of smaller, rural multi-grade schools has become a necessity. The alternative – which is to close smaller schools and operate fewer, bigger schools at an affordable and reasonable cost - would deny rural communities access to schooling. This thesis is a case study of the leadership and management challenges of multigrade schooling in a single school. The goal was to understand how education managers and leaders perceived their role in making it possible for teachers and learners to cope with multi-grade teaching. I worked in the interpretive paradigm to be able to interpret the social and cultural context of a rural, multi-grade school in the Karas region. The methods included questionnaires, interviews and observation. One of the leadership models universally considered to be available to principals of multi-grade schools is instructional leadership. My study revealed that the concept was unknown to teaching staff, although there were indications that the model had been encountered. My findings also revealed that the communication between colleges of education and the regional education department staff was very limited. One of the major issues that arose was that principals were so occupied with teaching that important issues about training/evaluation and supervision of teachers, the ‘visibility’ of the principal, setting and implementation of the aims and goals of the school and regular communication with parents and community leaders were neglected. Probably the most significant finding was that head teachers are not trained in the management of a multi-grade school, hence most if not all of the head teachers run multi-grade schools like a single-graded school. The single most important problem was that the importance of multi-grade teaching had never been highlighted, particularly in light of new staffing norms, in spite of the fact that it was a phenomenon that was likely to be a permanent arrangement.
- Full Text:
- Authors: Titus, David Petrus
- Date: 2004
- Subjects: Education -- Namibia Education, Rural -- Namibia Education and state -- Namibia Educational change -- Namibia School management and organization -- Namibia Rural schools -- Namibia Educational leadership -- Namibia School principals -- Namibia
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1566 , http://hdl.handle.net/10962/d1003448
- Description: Leadership has received much attention in both the business world and education. My thesis explores effective educational leadership through examining the management and leadership challenges that face principals in a multi-grade school. Schools in sparsely populated rural areas in Namibia have had to resort to multi-grade teaching to be able to be economically viable. Hard economic realities force people to move to bigger towns and cities. The constant demand for better schools, effective principals, qualified teachers and an improved service to the communities coupled with the demand for better working conditions and salaries for teachers drained the education budget even further. To keep in line with the four major policies of education namely equity, access, quality and democracy, the operation of smaller, rural multi-grade schools has become a necessity. The alternative – which is to close smaller schools and operate fewer, bigger schools at an affordable and reasonable cost - would deny rural communities access to schooling. This thesis is a case study of the leadership and management challenges of multigrade schooling in a single school. The goal was to understand how education managers and leaders perceived their role in making it possible for teachers and learners to cope with multi-grade teaching. I worked in the interpretive paradigm to be able to interpret the social and cultural context of a rural, multi-grade school in the Karas region. The methods included questionnaires, interviews and observation. One of the leadership models universally considered to be available to principals of multi-grade schools is instructional leadership. My study revealed that the concept was unknown to teaching staff, although there were indications that the model had been encountered. My findings also revealed that the communication between colleges of education and the regional education department staff was very limited. One of the major issues that arose was that principals were so occupied with teaching that important issues about training/evaluation and supervision of teachers, the ‘visibility’ of the principal, setting and implementation of the aims and goals of the school and regular communication with parents and community leaders were neglected. Probably the most significant finding was that head teachers are not trained in the management of a multi-grade school, hence most if not all of the head teachers run multi-grade schools like a single-graded school. The single most important problem was that the importance of multi-grade teaching had never been highlighted, particularly in light of new staffing norms, in spite of the fact that it was a phenomenon that was likely to be a permanent arrangement.
- Full Text:
The importance of non-timber forest products in rural livelihood security and as safety nets: a review of evidence from South Africa
- Shackleton, Charlie M, Shackleton, Sheona E
- Authors: Shackleton, Charlie M , Shackleton, Sheona E
- Date: 2004
- Language: English
- Type: Article
- Identifier: vital:6650 , http://hdl.handle.net/10962/d1007061
- Description: We review and synthesize recent South African work that examines the role and importance of non-timber forest products (NTFPs) in the daily lives of rural people in South Africa. The most commonly used such products are wild spinaches, fuelwood, wooden utensils edible fruits, grass hand-brushes, and twig hand-brushes, used by 85% or more of households. More than half the households investigated also make use of edible insects, wood for construction, bushmeat, wild honey and reeds for weaving. Individual households may exploit dozens of animal and plant species. The range in annual, direct-use values is large, from less than R1000 per household per year to over R12 000. The value to rural households is manifest through a daily net function which represents a cost saving to the families involved and to the state, as well as through an emergency net, which serves as an insurance in times of misfortune, such as drought, disease, and unexpected economic hardship. The emergency net function has hardly been quantified in South Africa and internationally. Ad hoc trade in NTFPs is a common emergency net, which in some instances evolves into a permanent way of life. Financial returns from trade are variable, depending on resource type and hours worked, but are typically low. Despite the small cash incomes from trade, they provide an important contribution that complement the diverse livelihood strategies within a household, especially for the poorer sectors of rural society. Moreover, there are non-financial benefits of NTFP trade that are commonly overlooked.
- Full Text:
- Authors: Shackleton, Charlie M , Shackleton, Sheona E
- Date: 2004
- Language: English
- Type: Article
- Identifier: vital:6650 , http://hdl.handle.net/10962/d1007061
- Description: We review and synthesize recent South African work that examines the role and importance of non-timber forest products (NTFPs) in the daily lives of rural people in South Africa. The most commonly used such products are wild spinaches, fuelwood, wooden utensils edible fruits, grass hand-brushes, and twig hand-brushes, used by 85% or more of households. More than half the households investigated also make use of edible insects, wood for construction, bushmeat, wild honey and reeds for weaving. Individual households may exploit dozens of animal and plant species. The range in annual, direct-use values is large, from less than R1000 per household per year to over R12 000. The value to rural households is manifest through a daily net function which represents a cost saving to the families involved and to the state, as well as through an emergency net, which serves as an insurance in times of misfortune, such as drought, disease, and unexpected economic hardship. The emergency net function has hardly been quantified in South Africa and internationally. Ad hoc trade in NTFPs is a common emergency net, which in some instances evolves into a permanent way of life. Financial returns from trade are variable, depending on resource type and hours worked, but are typically low. Despite the small cash incomes from trade, they provide an important contribution that complement the diverse livelihood strategies within a household, especially for the poorer sectors of rural society. Moreover, there are non-financial benefits of NTFP trade that are commonly overlooked.
- Full Text:
The kaolinitic clay deposits on Beaconsfield, north of Grahamstown
- Jacob, Roger E, Mitha, Vindina R, MacPherson, D
- Authors: Jacob, Roger E , Mitha, Vindina R , MacPherson, D
- Date: 2004
- Language: English
- Type: Article
- Identifier: vital:6734 , http://hdl.handle.net/10962/d1007544
- Description: The Grahamstown clay deposits occur below the Grahamstown Formation silcrete, which forms a remnant of an extensive peneplain that developed on the African erosion surface during the Cretaceous–Tertiary period. This paper provides new data on the distribution of the kaolinitic clay deposits in the Beaconsfield area north of Grahamstown. These data include 23 borehole profiles through the deposits, and the chemistry and mineralogy of the clays. Relatively little information is available on this part of the peneplain. It was found that the thickness of the kaolin horizon varies considerably, but reaches 35m in places. It generally occurs under a silcrete cover, which attains a thickness of 8 m in places. Lithological logs enable direct comparison across the Beaconsfield area. The clays are developed in both the Witteberg Group shale and Dwyka Group tillite. The contact between the clay and underlying bedrock is gradational and relatively uneven. Major-element X-ray fluorescence analyses revealed that there is chemical variation, both vertically and laterally. Al2O3 content is generally near 20%, but may reach 29%. SiO2 content varies between 55 and 70+%. SiO2 contents are highest in the silcretes occurring just below soil level. Fe2O3 is high locally in the top part of the profile. K2O and Na2O are generally low, but increase towards the unweathered bedrock as the primary feldspar content increases. These compositional variations are compatible with residual concentrations of kaolinitic clays through deep weathering below the former African erosion surface.
- Full Text:
- Authors: Jacob, Roger E , Mitha, Vindina R , MacPherson, D
- Date: 2004
- Language: English
- Type: Article
- Identifier: vital:6734 , http://hdl.handle.net/10962/d1007544
- Description: The Grahamstown clay deposits occur below the Grahamstown Formation silcrete, which forms a remnant of an extensive peneplain that developed on the African erosion surface during the Cretaceous–Tertiary period. This paper provides new data on the distribution of the kaolinitic clay deposits in the Beaconsfield area north of Grahamstown. These data include 23 borehole profiles through the deposits, and the chemistry and mineralogy of the clays. Relatively little information is available on this part of the peneplain. It was found that the thickness of the kaolin horizon varies considerably, but reaches 35m in places. It generally occurs under a silcrete cover, which attains a thickness of 8 m in places. Lithological logs enable direct comparison across the Beaconsfield area. The clays are developed in both the Witteberg Group shale and Dwyka Group tillite. The contact between the clay and underlying bedrock is gradational and relatively uneven. Major-element X-ray fluorescence analyses revealed that there is chemical variation, both vertically and laterally. Al2O3 content is generally near 20%, but may reach 29%. SiO2 content varies between 55 and 70+%. SiO2 contents are highest in the silcretes occurring just below soil level. Fe2O3 is high locally in the top part of the profile. K2O and Na2O are generally low, but increase towards the unweathered bedrock as the primary feldspar content increases. These compositional variations are compatible with residual concentrations of kaolinitic clays through deep weathering below the former African erosion surface.
- Full Text:
The location of meaning in the postmodernist literary text: a reading of Mark Z. Danielewski's House of Leaves and related material
- Authors: Jeffery, Thomas Carnegie
- Date: 2004
- Subjects: Danielewski, Mark Z. House of leaves , Danielewski, Mark Z. Criticism and interpretation , Horror tales , English literature -- Criticism, Textual , Literature, Modern -- History and criticism , Postmodernism (Literature)
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2196 , http://hdl.handle.net/10962/d1002238
- Description: In House of Leaves, Mark Z. Danielewski has produced a text which epitomises the traits and concerns of postmodernist literature. Through his attention to aspects such as metafiction, intertextuality and parody, Danielewski develops a narrative structure which is best understood as a literary labyrinth. It is a structure intended to reflect the social conditions of the twenty-first century and comment on the experience of people living at this time. Some of the meaning-making strategies within the book’s labyrinthine structure are thus discussed in detail in order to demonstrate the relevance and importance of House of Leaves as social commentary. House of Leaves is an exemplary postmodernist text, but it is also one that seeks to guide the reader beyond the intellectual impasse of the postmodernist paradigm toward a renewed ethical and political engagement with the world. One of the most important goals of both Danielewski’s novel and this thesis is to attempt to redefine the postmodernist perspective in such a way as to insist on the necessity of what I call a new realism. This is founded upon an awareness of the pervasiveness of the self-perpetuating ideology of capitalism, even in the perspective of postmodernism (which purports to subvert all authoritative ideologies). Playing a crucial role in perpetuating the status quo of capitalism is the growth of entertainment culture, which works to sideline crucial political issues by replacing information with infotainment. The result is an intensification of the processes of commodification. Such an intensification, it is argued, may be countered by a radical scepticism which draws upon the methods and insights of contemporary science.
- Full Text:
- Authors: Jeffery, Thomas Carnegie
- Date: 2004
- Subjects: Danielewski, Mark Z. House of leaves , Danielewski, Mark Z. Criticism and interpretation , Horror tales , English literature -- Criticism, Textual , Literature, Modern -- History and criticism , Postmodernism (Literature)
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2196 , http://hdl.handle.net/10962/d1002238
- Description: In House of Leaves, Mark Z. Danielewski has produced a text which epitomises the traits and concerns of postmodernist literature. Through his attention to aspects such as metafiction, intertextuality and parody, Danielewski develops a narrative structure which is best understood as a literary labyrinth. It is a structure intended to reflect the social conditions of the twenty-first century and comment on the experience of people living at this time. Some of the meaning-making strategies within the book’s labyrinthine structure are thus discussed in detail in order to demonstrate the relevance and importance of House of Leaves as social commentary. House of Leaves is an exemplary postmodernist text, but it is also one that seeks to guide the reader beyond the intellectual impasse of the postmodernist paradigm toward a renewed ethical and political engagement with the world. One of the most important goals of both Danielewski’s novel and this thesis is to attempt to redefine the postmodernist perspective in such a way as to insist on the necessity of what I call a new realism. This is founded upon an awareness of the pervasiveness of the self-perpetuating ideology of capitalism, even in the perspective of postmodernism (which purports to subvert all authoritative ideologies). Playing a crucial role in perpetuating the status quo of capitalism is the growth of entertainment culture, which works to sideline crucial political issues by replacing information with infotainment. The result is an intensification of the processes of commodification. Such an intensification, it is argued, may be countered by a radical scepticism which draws upon the methods and insights of contemporary science.
- Full Text:
The market efficiency hypothesis and the behaviour of stock returns on the JSE securities exchange
- Authors: Mabhunu, Mind
- Date: 2004
- Subjects: Johannesburg Stock Exchange , Stocks -- Prices -- South Africa , Stock exchanges -- South Africa
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:1027 , http://hdl.handle.net/10962/d1002762 , Johannesburg Stock Exchange , Stocks -- Prices -- South Africa , Stock exchanges -- South Africa
- Description: While the Efficient Market Hypothesis (EHM) has been widely accepted as robust by many researchers in the field of capital markets, the hypothesis’ robustness has been under increased scrutiny and question lately. In the light of the concerns over the robustness of the EMH, the weak form efficiency of the JSE is tested. Stock returns used in the analysis were controlled for thin trading and it was discovered that once returns are controlled for thin trading, they are independent of each other across time. Some of the previous studies found the JSE to be inefficient in the weak form but this research found that the JSE is efficient in the weak form. A comparison is also made between the JSE and four other African stock markets and the JSE is found to be more efficient than the other markets. The developments on the JSE, which have improved information dissemination as well as the efficiency of trading, contributed to the improvement of the JSE’s efficiency. The improvement in operational efficiency and turnover from the late 1990s has also made a major contribution to the improvement in the weak form efficiency of the JSE. Theory proposes that if markets are efficient then professional investment management is of little value if any; hence the position of professional investment managers in efficient markets is investigated. Although the JSE is found to be efficient, at least in the weak form, it is argued that achieving efficiency does not necessarily make the investment manager’s role obsolete. Investment managers are needed even when the market can be proved to be efficient.
- Full Text:
- Authors: Mabhunu, Mind
- Date: 2004
- Subjects: Johannesburg Stock Exchange , Stocks -- Prices -- South Africa , Stock exchanges -- South Africa
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:1027 , http://hdl.handle.net/10962/d1002762 , Johannesburg Stock Exchange , Stocks -- Prices -- South Africa , Stock exchanges -- South Africa
- Description: While the Efficient Market Hypothesis (EHM) has been widely accepted as robust by many researchers in the field of capital markets, the hypothesis’ robustness has been under increased scrutiny and question lately. In the light of the concerns over the robustness of the EMH, the weak form efficiency of the JSE is tested. Stock returns used in the analysis were controlled for thin trading and it was discovered that once returns are controlled for thin trading, they are independent of each other across time. Some of the previous studies found the JSE to be inefficient in the weak form but this research found that the JSE is efficient in the weak form. A comparison is also made between the JSE and four other African stock markets and the JSE is found to be more efficient than the other markets. The developments on the JSE, which have improved information dissemination as well as the efficiency of trading, contributed to the improvement of the JSE’s efficiency. The improvement in operational efficiency and turnover from the late 1990s has also made a major contribution to the improvement in the weak form efficiency of the JSE. Theory proposes that if markets are efficient then professional investment management is of little value if any; hence the position of professional investment managers in efficient markets is investigated. Although the JSE is found to be efficient, at least in the weak form, it is argued that achieving efficiency does not necessarily make the investment manager’s role obsolete. Investment managers are needed even when the market can be proved to be efficient.
- Full Text:
The mentally retarded offender in a forensic setting: a South African study
- Authors: Solomons, Warren Stanley
- Date: 2004
- Subjects: Mentally ill offenders -- South Africa , Forensic psychology , People with mental disabilities and crime -- South Africa , People with mental disabilities -- Rehabilitation , Mental health laws -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3063 , http://hdl.handle.net/10962/d1002572 , Mentally ill offenders -- South Africa , Forensic psychology , People with mental disabilities and crime -- South Africa , People with mental disabilities -- Rehabilitation , Mental health laws -- South Africa
- Description: This study examined, within the South African context, the prevalence of mental retardation in a forensic observation setting, and the impediments of and successes to forensic rehabilitation. The results of the study indicated that a significant amount of forensic observation patients (25.16%) are ultimately diagnosed as being mentally retarded, with 39.24 percent of such offenders being found unfit to plead. Further 32.91 percent of the same sample was found to be not responsible for their actions. A link was also drawn between the mentally retarded offender and violent offenses. The advantages and disadvantages of a current rehabilitative process are discussed in light of alternate community-based forms of rehabilitation that are being implemented in other countries, for example the United States of America, with a view towards investigated their usefulness and adaptability to South African circumstances. The findings of the study have implications for mental health professionals working within forensic settings concerning the future management of mentally retarded offenders, particularly within the rehabilitative process .
- Full Text:
- Authors: Solomons, Warren Stanley
- Date: 2004
- Subjects: Mentally ill offenders -- South Africa , Forensic psychology , People with mental disabilities and crime -- South Africa , People with mental disabilities -- Rehabilitation , Mental health laws -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3063 , http://hdl.handle.net/10962/d1002572 , Mentally ill offenders -- South Africa , Forensic psychology , People with mental disabilities and crime -- South Africa , People with mental disabilities -- Rehabilitation , Mental health laws -- South Africa
- Description: This study examined, within the South African context, the prevalence of mental retardation in a forensic observation setting, and the impediments of and successes to forensic rehabilitation. The results of the study indicated that a significant amount of forensic observation patients (25.16%) are ultimately diagnosed as being mentally retarded, with 39.24 percent of such offenders being found unfit to plead. Further 32.91 percent of the same sample was found to be not responsible for their actions. A link was also drawn between the mentally retarded offender and violent offenses. The advantages and disadvantages of a current rehabilitative process are discussed in light of alternate community-based forms of rehabilitation that are being implemented in other countries, for example the United States of America, with a view towards investigated their usefulness and adaptability to South African circumstances. The findings of the study have implications for mental health professionals working within forensic settings concerning the future management of mentally retarded offenders, particularly within the rehabilitative process .
- Full Text:
The microstructure of plasmodesmata in internodal stem tissue of the Saccharum hybrid var. NCo376 : evidence for an apoplasmic loading pathway
- Botha, Christiaan E J, Cross, Robin H M, Gerber, Jacques
- Authors: Botha, Christiaan E J , Cross, Robin H M , Gerber, Jacques
- Date: 2004
- Language: English
- Type: Article
- Identifier: vital:6494 , http://hdl.handle.net/10962/d1004487
- Description: The distribution, structure and functional state of plasmodesmata were investigated to gain a clearer understanding of the sucrose transport pathway to the storage parenchyma cells in stem tissue in Saccharum officinarum var. NCo376. Evidence from structural studies on sugarcane stems by electron microscopy indicated that there are numerous plasmodesmata from the vascular bundles through to the storage parenchyma cells in mature stem tissue. Our studies, supported by fluorescence microscopy and iontophoresis, indicate that there are functional plasmodesmata in the phloemunloading pathway from transport phloem tissue to the bundle sheath in Saccharum, which could support symplasmic transport; plasmodesmata outside of the sheath cells in the storage parenchyma appear to be constricted by sphincter-like structures within their neck regions. Staining with Aniline Blue revealed evidence of large callose deposits, which co-localized with plasmodesmatal aggregates in the walls of the storage parenchyma cells. This suggests that the sucrose transport into, and accumulation by, storage parenchyma of mature stem tissue is under apoplasmic control.
- Full Text:
- Authors: Botha, Christiaan E J , Cross, Robin H M , Gerber, Jacques
- Date: 2004
- Language: English
- Type: Article
- Identifier: vital:6494 , http://hdl.handle.net/10962/d1004487
- Description: The distribution, structure and functional state of plasmodesmata were investigated to gain a clearer understanding of the sucrose transport pathway to the storage parenchyma cells in stem tissue in Saccharum officinarum var. NCo376. Evidence from structural studies on sugarcane stems by electron microscopy indicated that there are numerous plasmodesmata from the vascular bundles through to the storage parenchyma cells in mature stem tissue. Our studies, supported by fluorescence microscopy and iontophoresis, indicate that there are functional plasmodesmata in the phloemunloading pathway from transport phloem tissue to the bundle sheath in Saccharum, which could support symplasmic transport; plasmodesmata outside of the sheath cells in the storage parenchyma appear to be constricted by sphincter-like structures within their neck regions. Staining with Aniline Blue revealed evidence of large callose deposits, which co-localized with plasmodesmatal aggregates in the walls of the storage parenchyma cells. This suggests that the sucrose transport into, and accumulation by, storage parenchyma of mature stem tissue is under apoplasmic control.
- Full Text:
The new economic geography of SADC free trade area
- Authors: Hess, Simon Peter
- Date: 2004
- Subjects: Southern African Development Community Free trade -- Africa, Southern Economic geography Industries -- Africa, Southern
- Language: English
- Type: Thesis , Masters , MEcon
- Identifier: vital:932 , http://hdl.handle.net/10962/d1001648
- Description: The current implementation of a free trade area in SADC has given rise to concerns that the present location of industry in the region will be adversely affected. Specifically, many of the smaller and less-developed countries fear that this change will result in a loss of their industry towards the more developed members, and particularly towards South Africa. This study uses the framework of the new economic geography to address these concerns. The new economic geography is a body of theory that has arisen in the last decade and allows for a dynamic analysis of the process of regional integration. Studies of such dynamic effects in the developing country context are exceedingly scarce, and particularly so in southern Africa. Another area of little research is in the comparison of the evolving industrial structure of different regional blocs. Thus, in response to this gap in the literature and in order to address the concerns of polarisation of industry within the SADC region, a two-pronged empirical approach is taken. The study first conducts a review of the spatial distribution of industry within SADC from 1970 to 1999. This is achieved through the calculation and examination of industrial locational Gini coefficients, measuring the relative degree of concentration of 28 ISIC (rev 2) industries for the years 1970, 1980, 1985, 1990, 1995 and 1999. Secondly, an empirical comparison is conducted with other blocs that are in the process of deepening regional integration, namely the European Union and Mercosur. Again, this is done through the calculation of locational Gini coefficients for individual industries for all three blocs at five year intervals from 1980 to 1995, and then for 1999. The average level of concentration within SADC is found to increase steadily from 1970 to 1990. Between 1990 and 1995, the level of concentration increases further, but at a lower rate, and, by 1999 industry begins to disperse. The Gini coefficient is a relative measure, and thus does not measure the absolute level of concentration. Thus, much of the increase in concentration seen is towards peripheral countries. To further interpret the Gini, the changes in concentration are compared to the absolute changes in manufacturing employment in South Africa. From this analysis, eight of the 28 industries analysed show particular tendencies to concentrate in the periphery. These are beverages, textiles, wearing apparel, paper and products, rubber products, other non-metallic mineral products, transport equipment, and professional and scientific equipment. Likewise, another six industries become more concentrated in South Africa over this time, namely food products, printing and publishing, industrial chemicals, petroleum refineries, miscellaneous petroleum and coal products, and electrical machinery. According to the Gini coefficient, the tobacco industry is by far the most concentrated, while the wood products industry is the most dispersed. It is also found that scale-intensive industries tend to be among the most concentrated. In the cross-bloc comparison, Mercosur has the lowest level of aggregate concentration with an average Gini of 0.08 in 1999. This compares with Ginis of 0.28 for the EU, and 0.22 for SADC. The EU has the largest increase in concentration over the period, while the concentration in Mercosur falls during the 1980s, increases in the mid 1990s and then falls again by 1999. A common theme, however, between all three blocs is a trend towards dispersion in the late 1990s. This is particularly apparent in SADC and Mercosur where the Gini decreases in value, while in the EU, the Gini only increases marginally in this period. Other studies of the EU have indicated that industry was starting to disperse at this time. This finding would be more apparent at a greater level of industrial disaggregation. The following industries are found to be agglomerated above the average level in all three blocs: tobacco, miscellaneous petroleum and coal products, and pottery china and earthenware. Conversely, transport equipment, paper and products, machinery except electrical, plastic products, rubber products, and fabricated metal products tend to be more dispersed across all three. Perhaps more interesting is that there appears to be some commonality between industries that become more agglomerated across all three blocs, while industries that dispersed tend to be region specific. The industries that show universal agglomeration tendencies are the highly sensitive wearing apparel and textiles industries, in addition to industrial chemicals, printing and publishing, iron and steel, and plastic products. In relation to SADC, the first two of these industries show an increased concentration in the periphery, as in the EU, while the remaining industries show tendencies to concentrate in the core. The new economic geography predicts that, as the presently high levels of transport costs begin to fall in SADC, industry will tend to concentrate in the core. However, the results of this study indicate that the effect on manufacturing is, to a large extent, sector specific, with some manufacturing industries concentrating in the core and others in the periphery. The study therefore concludes that the mass polarization of industry from the smaller countries in SADC towards South Africa is unlikely to occur with the further reduction in trade costs. Although certain industries may be attracted towards the core, the high degree of wage disparity in the region and present trade concessions from developed markets overseas towards the peripheral countries, will make these countries an attractive location, particularly for export orientated firms. Two main policy recommendations result from the study. Firstly, individual countries in SADC need to promote those industries that show concentration tendencies in their country. Secondly, in order for the periphery to maximize their gain from the free trade area, transport costs within the region need to be reduced rapidly and effectively.
- Full Text:
- Authors: Hess, Simon Peter
- Date: 2004
- Subjects: Southern African Development Community Free trade -- Africa, Southern Economic geography Industries -- Africa, Southern
- Language: English
- Type: Thesis , Masters , MEcon
- Identifier: vital:932 , http://hdl.handle.net/10962/d1001648
- Description: The current implementation of a free trade area in SADC has given rise to concerns that the present location of industry in the region will be adversely affected. Specifically, many of the smaller and less-developed countries fear that this change will result in a loss of their industry towards the more developed members, and particularly towards South Africa. This study uses the framework of the new economic geography to address these concerns. The new economic geography is a body of theory that has arisen in the last decade and allows for a dynamic analysis of the process of regional integration. Studies of such dynamic effects in the developing country context are exceedingly scarce, and particularly so in southern Africa. Another area of little research is in the comparison of the evolving industrial structure of different regional blocs. Thus, in response to this gap in the literature and in order to address the concerns of polarisation of industry within the SADC region, a two-pronged empirical approach is taken. The study first conducts a review of the spatial distribution of industry within SADC from 1970 to 1999. This is achieved through the calculation and examination of industrial locational Gini coefficients, measuring the relative degree of concentration of 28 ISIC (rev 2) industries for the years 1970, 1980, 1985, 1990, 1995 and 1999. Secondly, an empirical comparison is conducted with other blocs that are in the process of deepening regional integration, namely the European Union and Mercosur. Again, this is done through the calculation of locational Gini coefficients for individual industries for all three blocs at five year intervals from 1980 to 1995, and then for 1999. The average level of concentration within SADC is found to increase steadily from 1970 to 1990. Between 1990 and 1995, the level of concentration increases further, but at a lower rate, and, by 1999 industry begins to disperse. The Gini coefficient is a relative measure, and thus does not measure the absolute level of concentration. Thus, much of the increase in concentration seen is towards peripheral countries. To further interpret the Gini, the changes in concentration are compared to the absolute changes in manufacturing employment in South Africa. From this analysis, eight of the 28 industries analysed show particular tendencies to concentrate in the periphery. These are beverages, textiles, wearing apparel, paper and products, rubber products, other non-metallic mineral products, transport equipment, and professional and scientific equipment. Likewise, another six industries become more concentrated in South Africa over this time, namely food products, printing and publishing, industrial chemicals, petroleum refineries, miscellaneous petroleum and coal products, and electrical machinery. According to the Gini coefficient, the tobacco industry is by far the most concentrated, while the wood products industry is the most dispersed. It is also found that scale-intensive industries tend to be among the most concentrated. In the cross-bloc comparison, Mercosur has the lowest level of aggregate concentration with an average Gini of 0.08 in 1999. This compares with Ginis of 0.28 for the EU, and 0.22 for SADC. The EU has the largest increase in concentration over the period, while the concentration in Mercosur falls during the 1980s, increases in the mid 1990s and then falls again by 1999. A common theme, however, between all three blocs is a trend towards dispersion in the late 1990s. This is particularly apparent in SADC and Mercosur where the Gini decreases in value, while in the EU, the Gini only increases marginally in this period. Other studies of the EU have indicated that industry was starting to disperse at this time. This finding would be more apparent at a greater level of industrial disaggregation. The following industries are found to be agglomerated above the average level in all three blocs: tobacco, miscellaneous petroleum and coal products, and pottery china and earthenware. Conversely, transport equipment, paper and products, machinery except electrical, plastic products, rubber products, and fabricated metal products tend to be more dispersed across all three. Perhaps more interesting is that there appears to be some commonality between industries that become more agglomerated across all three blocs, while industries that dispersed tend to be region specific. The industries that show universal agglomeration tendencies are the highly sensitive wearing apparel and textiles industries, in addition to industrial chemicals, printing and publishing, iron and steel, and plastic products. In relation to SADC, the first two of these industries show an increased concentration in the periphery, as in the EU, while the remaining industries show tendencies to concentrate in the core. The new economic geography predicts that, as the presently high levels of transport costs begin to fall in SADC, industry will tend to concentrate in the core. However, the results of this study indicate that the effect on manufacturing is, to a large extent, sector specific, with some manufacturing industries concentrating in the core and others in the periphery. The study therefore concludes that the mass polarization of industry from the smaller countries in SADC towards South Africa is unlikely to occur with the further reduction in trade costs. Although certain industries may be attracted towards the core, the high degree of wage disparity in the region and present trade concessions from developed markets overseas towards the peripheral countries, will make these countries an attractive location, particularly for export orientated firms. Two main policy recommendations result from the study. Firstly, individual countries in SADC need to promote those industries that show concentration tendencies in their country. Secondly, in order for the periphery to maximize their gain from the free trade area, transport costs within the region need to be reduced rapidly and effectively.
- Full Text:
The new media maelstrom:
- Authors: Berger, Guy
- Date: 2004
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/159192 , vital:40276 , https://hdl.handle.net/10520/EJC146201
- Description: South Africa's democracy decade coincided with the popularisation of the Internet on a global scale. New society, new media, it seemed.
- Full Text:
- Authors: Berger, Guy
- Date: 2004
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/159192 , vital:40276 , https://hdl.handle.net/10520/EJC146201
- Description: South Africa's democracy decade coincided with the popularisation of the Internet on a global scale. New society, new media, it seemed.
- Full Text:
The occurrence of Nosema apis (Zander), Acarapis woodi (Rennie), and the Cape problem bee in the summer rainfall region of South Africa
- Authors: Swart, Dawid Johannes
- Date: 2004
- Subjects: Nosema apis , Bee culture , Honeybee -- South Africa , Honeybee -- Diseases , Honeybee -- Parasites , Mites
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5914 , http://hdl.handle.net/10962/d1015980
- Description: The occurrence of Nosema disease, tracheal mites and the “pseudo-parasitic” behaviour of Cape honeybee workers when placed amongst African honeybees – known as the Cape Bee Problem – were studied over a 18 month period. Three surveys, approximately 6 months apart were done. The aims of this study were to establish the distribution and severity of the diseases and compare the disease with the presence of the Cape Bee Problem. Before this survey commenced European Foul Brood disease, Sacbrood (virus), Nosema, Brood nosema, and Tracheal mite have sporadically been reported in the summer rainfall region of South Africa. In the first survey 1005 colonies in 61 apiaries were surveyed, 803 colonies in 57 apiaries in the second, and 458 colonies in 41 apiaries in the third. Samples for disease and parasite analysis were taken at 4 colonies per apiary. Ten colonies per apiary were inspected for Cape Problem Bees, and samples of workers were collected and dissected at each of these colonies. Even with the addition of apiaries to 'fill-up' lost colonies during the second survey, 63% of all colonies were lost by the third survey. There was only a small difference in colony loss between sedentary and migratory beekeepers of 22% compared to 27%. Nosema was more prevalent amongst commercial beekeepers and increased in migratory operations during the survey period. The percentage of colonies infected increased during the survey period from 23% to 32% to 34%. The placement of colonies in Eucalyptus plantations may boost infection. Trachea mites seem to have spread quite rapidly in South Africa since its discovery. This parasitic mite was present in all regions, although in low numbers in three most northern regions. Sedentary colonies had higher levels of infestation than migratory colonies. The number of colonies infested diminished over the survey period, which may be a result of general colony loss. The Cape Problem Bee was less of a problem than anticipated. Colonies succumbed to Cape Problem Bees in all regions. When beekeepers reported high levels of infestation in their bee stocks the colonies would be dead within six months. In apiaries with low infestation the die-out was slower.
- Full Text:
- Authors: Swart, Dawid Johannes
- Date: 2004
- Subjects: Nosema apis , Bee culture , Honeybee -- South Africa , Honeybee -- Diseases , Honeybee -- Parasites , Mites
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5914 , http://hdl.handle.net/10962/d1015980
- Description: The occurrence of Nosema disease, tracheal mites and the “pseudo-parasitic” behaviour of Cape honeybee workers when placed amongst African honeybees – known as the Cape Bee Problem – were studied over a 18 month period. Three surveys, approximately 6 months apart were done. The aims of this study were to establish the distribution and severity of the diseases and compare the disease with the presence of the Cape Bee Problem. Before this survey commenced European Foul Brood disease, Sacbrood (virus), Nosema, Brood nosema, and Tracheal mite have sporadically been reported in the summer rainfall region of South Africa. In the first survey 1005 colonies in 61 apiaries were surveyed, 803 colonies in 57 apiaries in the second, and 458 colonies in 41 apiaries in the third. Samples for disease and parasite analysis were taken at 4 colonies per apiary. Ten colonies per apiary were inspected for Cape Problem Bees, and samples of workers were collected and dissected at each of these colonies. Even with the addition of apiaries to 'fill-up' lost colonies during the second survey, 63% of all colonies were lost by the third survey. There was only a small difference in colony loss between sedentary and migratory beekeepers of 22% compared to 27%. Nosema was more prevalent amongst commercial beekeepers and increased in migratory operations during the survey period. The percentage of colonies infected increased during the survey period from 23% to 32% to 34%. The placement of colonies in Eucalyptus plantations may boost infection. Trachea mites seem to have spread quite rapidly in South Africa since its discovery. This parasitic mite was present in all regions, although in low numbers in three most northern regions. Sedentary colonies had higher levels of infestation than migratory colonies. The number of colonies infested diminished over the survey period, which may be a result of general colony loss. The Cape Problem Bee was less of a problem than anticipated. Colonies succumbed to Cape Problem Bees in all regions. When beekeepers reported high levels of infestation in their bee stocks the colonies would be dead within six months. In apiaries with low infestation the die-out was slower.
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