Becoming a business journalist in Malawi: a case study of The Daily Times and The Nation newspapers
- Authors: Manjawira, Ellard Spencer
- Date: 2010 , 2013-07-17
- Subjects: Journalists -- Malawi Journalism -- Study and teaching -- Malawi Journalists -- Training of -- Malawi Journalists -- Education -- Malawi
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3506 , http://hdl.handle.net/10962/d1007440
- Description: In the past few decades, the proportion of business news compared to general news has increased tremendously across all media platforms in Africa. While the critical role played by business journalism is recognised, little is known about the people who write and report such news. Most studies on business reporting have tended to focus on analysing the content of business news, rather than the specific processes through which business journalists are socialized and trained. The findings of this study are drawn mainly from in-depth interviews with business reporters and editors at two leading newspapers in Malawi, The Daily Times and The Nation. Three major findings emerge trom the study data. First, business journalists vary in their educational and professional backgrounds, as well as the reasons for working on this beat. Second, the majority of them have no prerequisite formal education and training in business journalism and, therefore, have little knowledge and skills about what constitute good business journalism. Third, professionalism in the sub-field is constrained by a host of factors, influence of advertisers being the critical one. The study recommends that business reporting become an integral component of journalism education and training programmes to adequately prepare future generations of business journalists. In addition there is need for media houses to devise strategies to counter obstacles that business journalists face for them to effectively contribute to political economy debate. , KMBT_363
- Full Text:
- Date Issued: 2010
- Authors: Manjawira, Ellard Spencer
- Date: 2010 , 2013-07-17
- Subjects: Journalists -- Malawi Journalism -- Study and teaching -- Malawi Journalists -- Training of -- Malawi Journalists -- Education -- Malawi
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3506 , http://hdl.handle.net/10962/d1007440
- Description: In the past few decades, the proportion of business news compared to general news has increased tremendously across all media platforms in Africa. While the critical role played by business journalism is recognised, little is known about the people who write and report such news. Most studies on business reporting have tended to focus on analysing the content of business news, rather than the specific processes through which business journalists are socialized and trained. The findings of this study are drawn mainly from in-depth interviews with business reporters and editors at two leading newspapers in Malawi, The Daily Times and The Nation. Three major findings emerge trom the study data. First, business journalists vary in their educational and professional backgrounds, as well as the reasons for working on this beat. Second, the majority of them have no prerequisite formal education and training in business journalism and, therefore, have little knowledge and skills about what constitute good business journalism. Third, professionalism in the sub-field is constrained by a host of factors, influence of advertisers being the critical one. The study recommends that business reporting become an integral component of journalism education and training programmes to adequately prepare future generations of business journalists. In addition there is need for media houses to devise strategies to counter obstacles that business journalists face for them to effectively contribute to political economy debate. , KMBT_363
- Full Text:
- Date Issued: 2010
Beta-N-methylamino-L-alanine in South African fresh water cyanobacteria : incidence, prevalence, ecotoxicological considerations and human exposure risk
- Authors: Esterhuizen-Londt, Maranda
- Date: 2010
- Subjects: Cyanobacteria , Bioaccumulation , Chromatographic analysis , Neurotoxic agents
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:10306 , http://hdl.handle.net/10948/1473 , Cyanobacteria , Bioaccumulation , Chromatographic analysis , Neurotoxic agents
- Description: β-N-methylamino-L-alanine (BMAA) is a non-proteinogenic amino acid associated with human neurodegenerative disease. Due to the cosmopolitan nature of cyanobacteria, detection of BMAA in cyanobacteria has caused concerns about human exposure risk. This study was therefore based on the hypothesis that BMAA poses a health risk to humans either by direct ingestion or by indirect exposure to BMAA from a cyanobacterial source via a freshwater food chain. A validated gas chromatography-mass spectrometry (GC-MS) BMAA analysis method and a confirmatory liquid chromatography-mass spectrometry (LC-MS) method, with improved sensitivity, were developed in addition to a LC-MS/MS method for analyte confirmation. These methods were used to quantify BMAA in South African cyanobacteria, isolated from various potable water reservoirs. The majority of the isolates tested, contained BMAA. Possible human exposure by direct consumption of BMAA released from cyanobacterial blooms was investigated by the development of a robust solid phase extraction (SPE) method used for BMAA concentration and quantification in raw and treated tap water. Despite the use of the SPE method that facilitated the concentration of BMAA from large quantities of water, no free dissolved BMAA was detected in raw or processed fresh water. The fate of exogenous BMAA was therefore investigated firstly by evaluating the efficacy of standard water treatment processes employed in South Africa and secondly by investigating the possibility of BMAA bioaccumulation and biomagnification in aquatic food chains. Standard water treatment processes proved highly efficient at removing free dissolved BMAA, explaining the absence of BMAA in treated tap water. However, the cause of the BMAA absence in raw potable water remained unknown. Uptake of BMAA by model aquatic organisms was investigated in controlled experiments. BMAA uptake was documented in both Ceratophyllum demersum and Daphnia magna, however, BMAA-protein association and biomagnification were not observed in D. magna. BMAA had an inhibitory effect on the oxidative stress enzyme acitivties of both organisms tested (as well as human S9 extracts), resulting in accumulation of detrimental reactive oxygen species (ROS) in the cells. Exposure of crop plants to BMAA in controlled experiments resulted in BMAA uptake, protein association, and subsequent inhibition of the antioxidative enzyme activities. However, BMAA was detected in neither free nor protein-associated form in natural crop plants irrigated with known BMAA-containing bloom water. Post-mortem liver samples of Clarias gariepinus (Catfish) and Crocodylus niloticus (Crocodile), from a natural fresh water ecosystem that experienced frequent cyanobacterial blooms, contained both free and protein-associated BMAA. Higher BMAA concentrations were found in crocodile liver samples compared to fish liver samples, strongly suggesting biomagnification from one trophic level to the next. BMAA concentrations corresponded to crocodile age. This is the first report of bioaccumulation and biomagnification in two trophic levels in a fresh water ecosystem. These findings strongly suggest possible human exposure via aquatic food chains of cyanobacterial origin. Direct BMAA exposure via drinking water is not plausible due to the efficiency of standard water treatment processes to remove BMAA. The use of raw water for agricultural and recreational use, however, remains a problem. The development of management strategies as well as daily tolerable levels for BMAA is urgently required.
- Full Text:
- Date Issued: 2010
- Authors: Esterhuizen-Londt, Maranda
- Date: 2010
- Subjects: Cyanobacteria , Bioaccumulation , Chromatographic analysis , Neurotoxic agents
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:10306 , http://hdl.handle.net/10948/1473 , Cyanobacteria , Bioaccumulation , Chromatographic analysis , Neurotoxic agents
- Description: β-N-methylamino-L-alanine (BMAA) is a non-proteinogenic amino acid associated with human neurodegenerative disease. Due to the cosmopolitan nature of cyanobacteria, detection of BMAA in cyanobacteria has caused concerns about human exposure risk. This study was therefore based on the hypothesis that BMAA poses a health risk to humans either by direct ingestion or by indirect exposure to BMAA from a cyanobacterial source via a freshwater food chain. A validated gas chromatography-mass spectrometry (GC-MS) BMAA analysis method and a confirmatory liquid chromatography-mass spectrometry (LC-MS) method, with improved sensitivity, were developed in addition to a LC-MS/MS method for analyte confirmation. These methods were used to quantify BMAA in South African cyanobacteria, isolated from various potable water reservoirs. The majority of the isolates tested, contained BMAA. Possible human exposure by direct consumption of BMAA released from cyanobacterial blooms was investigated by the development of a robust solid phase extraction (SPE) method used for BMAA concentration and quantification in raw and treated tap water. Despite the use of the SPE method that facilitated the concentration of BMAA from large quantities of water, no free dissolved BMAA was detected in raw or processed fresh water. The fate of exogenous BMAA was therefore investigated firstly by evaluating the efficacy of standard water treatment processes employed in South Africa and secondly by investigating the possibility of BMAA bioaccumulation and biomagnification in aquatic food chains. Standard water treatment processes proved highly efficient at removing free dissolved BMAA, explaining the absence of BMAA in treated tap water. However, the cause of the BMAA absence in raw potable water remained unknown. Uptake of BMAA by model aquatic organisms was investigated in controlled experiments. BMAA uptake was documented in both Ceratophyllum demersum and Daphnia magna, however, BMAA-protein association and biomagnification were not observed in D. magna. BMAA had an inhibitory effect on the oxidative stress enzyme acitivties of both organisms tested (as well as human S9 extracts), resulting in accumulation of detrimental reactive oxygen species (ROS) in the cells. Exposure of crop plants to BMAA in controlled experiments resulted in BMAA uptake, protein association, and subsequent inhibition of the antioxidative enzyme activities. However, BMAA was detected in neither free nor protein-associated form in natural crop plants irrigated with known BMAA-containing bloom water. Post-mortem liver samples of Clarias gariepinus (Catfish) and Crocodylus niloticus (Crocodile), from a natural fresh water ecosystem that experienced frequent cyanobacterial blooms, contained both free and protein-associated BMAA. Higher BMAA concentrations were found in crocodile liver samples compared to fish liver samples, strongly suggesting biomagnification from one trophic level to the next. BMAA concentrations corresponded to crocodile age. This is the first report of bioaccumulation and biomagnification in two trophic levels in a fresh water ecosystem. These findings strongly suggest possible human exposure via aquatic food chains of cyanobacterial origin. Direct BMAA exposure via drinking water is not plausible due to the efficiency of standard water treatment processes to remove BMAA. The use of raw water for agricultural and recreational use, however, remains a problem. The development of management strategies as well as daily tolerable levels for BMAA is urgently required.
- Full Text:
- Date Issued: 2010
Beyond Afrocentricism and Orientalism contemporary representations of transnational identities in the works of Nontsikelelo "Lolo" Veleko and Tracy Payne
- Authors: Pycroft, Hayley
- Date: 2010
- Subjects: Veleko, Nontsikelelo -- Criticism and interpretation Payne, Tracy, 1965- -- Criticism and interpretation Afrocentrism Orientalism Art and race Art and society Gender identity in art Art -- Political aspects Photographers -- South Africa Painters -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2420 , http://hdl.handle.net/10962/d1002216
- Description: South African photographer Nontsikelelo “Lolo” Veleko and South African painter Tracy Payne explore different ways of communicating African realities. The visual imagery of these two artists focuses a lot on movement, challenging the rigidity of boundaries set by Western social constructs. In their work, Veleko and Payne critique the limitations of terms such as “authenticity.” It is extremely difficult to portray shifting notions of contemporary African identity in light of the stain of colonial philosophies which have, in times past, exoticised and appropriated the African body and ascribed conventions of “authenticity” to African representations. Undermining the burden of Western boundaries1, Veleko and Payne redefine what it means to operate in Africa today. Veleko seeks additional cultural realities to complicate her identity as a woman living in Africa while Payne uses concepts of movement to question the validity of structures which advocate an either/ or binary such as “East” and “West” and “masculinity” and “femininity”. By subtly merging aspects of these binaries in their representations, Veleko and Payne bring transnational possibilities to light by undermining the restrictions inscribed in the social and political history of (South) Africa with regard to collective and individual identities. Constructs of gender have contributed to a heightened sense of “African” “masculinity,” forming a stereotype of the African body which is difficult to break free from. Considering the notion of transnationalism and the issue of moving beyond boundaries, borrowing aspects of different cultures in attempt to better define a sense of self, Veleko and Payne engage in the sampling of different lifestyles and perspectives to better define their individualities. This thesis seeks to provide an analysis of the visual language used by Veleko and Payne to promote fluid “African” identities.
- Full Text:
- Date Issued: 2010
- Authors: Pycroft, Hayley
- Date: 2010
- Subjects: Veleko, Nontsikelelo -- Criticism and interpretation Payne, Tracy, 1965- -- Criticism and interpretation Afrocentrism Orientalism Art and race Art and society Gender identity in art Art -- Political aspects Photographers -- South Africa Painters -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2420 , http://hdl.handle.net/10962/d1002216
- Description: South African photographer Nontsikelelo “Lolo” Veleko and South African painter Tracy Payne explore different ways of communicating African realities. The visual imagery of these two artists focuses a lot on movement, challenging the rigidity of boundaries set by Western social constructs. In their work, Veleko and Payne critique the limitations of terms such as “authenticity.” It is extremely difficult to portray shifting notions of contemporary African identity in light of the stain of colonial philosophies which have, in times past, exoticised and appropriated the African body and ascribed conventions of “authenticity” to African representations. Undermining the burden of Western boundaries1, Veleko and Payne redefine what it means to operate in Africa today. Veleko seeks additional cultural realities to complicate her identity as a woman living in Africa while Payne uses concepts of movement to question the validity of structures which advocate an either/ or binary such as “East” and “West” and “masculinity” and “femininity”. By subtly merging aspects of these binaries in their representations, Veleko and Payne bring transnational possibilities to light by undermining the restrictions inscribed in the social and political history of (South) Africa with regard to collective and individual identities. Constructs of gender have contributed to a heightened sense of “African” “masculinity,” forming a stereotype of the African body which is difficult to break free from. Considering the notion of transnationalism and the issue of moving beyond boundaries, borrowing aspects of different cultures in attempt to better define a sense of self, Veleko and Payne engage in the sampling of different lifestyles and perspectives to better define their individualities. This thesis seeks to provide an analysis of the visual language used by Veleko and Payne to promote fluid “African” identities.
- Full Text:
- Date Issued: 2010
Beyond coming out: lesbians' stories of sexual identity in the context of a historically white university
- Authors: Gibson, Alexandra Farren
- Date: 2010
- Subjects: Lesbianism -- South Africa -- Grahamstown Homosexuality -- South Africa -- Grahamstown Coming out (Sexual orientation) -- South Africa -- Grahamstown College students -- South Africa -- Grahamstown -- Sexual behavior Rhodes University College students -- South Africa -- Grahamstown -- Attitudes College students -- South Africa -- Grahamstown -- Social conditions College students -- South Africa -- Grahamstown -- Conduct of life College students -- South Africa -- Grahamstown -- Social life and customs Homosexuality and education -- South Africa -- Grahamstown Gender identity in education -- South Africa -- Grahamstown Discourse analysis, Narrative -- Psychological aspects Discursive psychology
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2981 , http://hdl.handle.net/10962/d1002490
- Description: Substantial contributions have been made by lesbian and gay developmental theorists in understanding the development of lesbian and gay sexual identities, or what has come to be known as the coming out process. “Coming out of the closet” has become a central metaphor, in western contexts, for the recognisable process gay men and lesbians undergo in order to claim a relatively stable and enduring sexual identity, while overcoming obstacles such as heterosexism. Lesbians’ sexual identities are examined in this thesis through a Foucauldian lens which is fused with a narrative-discursive perspective. The aim of this study is not to trace a progressive development of identity, but rather to consider how lesbians in this study are located within a specific context, namely, a historically white university in post-apartheid South Africa, and how their identities are dynamic products of ever-shifting socio-historical spaces. Eight lesbians’ stories are analysed using the narrative-discursive method, which allows for a consideration for how the construction and negotiation of identities is shaped and constrained by social and discursive conditions. The women in this study do utilise the concept of coming out to some extent in their stories, but this narrative does not entirely account for their experiences. Instead, these women’s accounts reflect the way in which they personally experience heterosexism, and how they constantly negotiate their sexual identities within certain social and geographical spaces. When the nuances of lesbians’ contexts are taken into account, it becomes clear that claiming a lesbian identity is more than just about “coming out”, and rather about an on-going process of identity management.
- Full Text:
- Date Issued: 2010
- Authors: Gibson, Alexandra Farren
- Date: 2010
- Subjects: Lesbianism -- South Africa -- Grahamstown Homosexuality -- South Africa -- Grahamstown Coming out (Sexual orientation) -- South Africa -- Grahamstown College students -- South Africa -- Grahamstown -- Sexual behavior Rhodes University College students -- South Africa -- Grahamstown -- Attitudes College students -- South Africa -- Grahamstown -- Social conditions College students -- South Africa -- Grahamstown -- Conduct of life College students -- South Africa -- Grahamstown -- Social life and customs Homosexuality and education -- South Africa -- Grahamstown Gender identity in education -- South Africa -- Grahamstown Discourse analysis, Narrative -- Psychological aspects Discursive psychology
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2981 , http://hdl.handle.net/10962/d1002490
- Description: Substantial contributions have been made by lesbian and gay developmental theorists in understanding the development of lesbian and gay sexual identities, or what has come to be known as the coming out process. “Coming out of the closet” has become a central metaphor, in western contexts, for the recognisable process gay men and lesbians undergo in order to claim a relatively stable and enduring sexual identity, while overcoming obstacles such as heterosexism. Lesbians’ sexual identities are examined in this thesis through a Foucauldian lens which is fused with a narrative-discursive perspective. The aim of this study is not to trace a progressive development of identity, but rather to consider how lesbians in this study are located within a specific context, namely, a historically white university in post-apartheid South Africa, and how their identities are dynamic products of ever-shifting socio-historical spaces. Eight lesbians’ stories are analysed using the narrative-discursive method, which allows for a consideration for how the construction and negotiation of identities is shaped and constrained by social and discursive conditions. The women in this study do utilise the concept of coming out to some extent in their stories, but this narrative does not entirely account for their experiences. Instead, these women’s accounts reflect the way in which they personally experience heterosexism, and how they constantly negotiate their sexual identities within certain social and geographical spaces. When the nuances of lesbians’ contexts are taken into account, it becomes clear that claiming a lesbian identity is more than just about “coming out”, and rather about an on-going process of identity management.
- Full Text:
- Date Issued: 2010
Bioaccumulation and ecotoxicology of b-methylamino-l-alanine (BMAA) in model crop plants
- Niyonzima, Francois Niyongabo
- Authors: Niyonzima, Francois Niyongabo
- Date: 2010
- Subjects: Cyanobacteria , Environmental toxicology
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10312 , http://hdl.handle.net/10948/1475 , Cyanobacteria , Environmental toxicology
- Description: Cyanobacteria are known to produce a variety of toxic compounds. β-N-methylamino-L-alanine (BMAA) is one of the neurotoxins produced by most cyanobacteria. BMAA has been implicated in amyotrophic lateral sclerosis / Parkinsonism dementia complex (ALS / PDC) and was suggested to contribute to this pathology after biomagnification and slow release of BMAA from a protein associated form. The uptake and accumulation of BMAA by the aquatic macrophyte Ceratophyllum demersum has recently been shown, but the consumption of aquatic macrophytes by humans is not typical. The uptake by, and accumulation in, crop plants (Nasturtium officinale and Daucus carota) was therefore investigated so as to establish the existence of any risk to humans from the consumption of plants irrigated with water from dams with high cyanobacterial biomass and therefore high BMAA levels. After the exposure to the BMAA through the growth medium, BMAA had no effect on growth and development of N. officinale and D. carota. The uptake and bioaccumulation of BMAA was observed in N. officinale and D. carota, and was found to be concentration-dependent. Both free and bound cellular BMAA was detected following BMAA exposure through the growth medium. The photosynthetic apparatus of N. officinale was not significantly damaged. The uptake and accumulation of BMAA in edible terrestrial plants may constitute another route of human exposure to BMAA; it may now be prudent to avoid spray irrigation of edible plants with waters from dams with high cyanobacterial biomass and therefore high BMAA levels. After uptake by plants, the cyanotoxins may induce oxidative stress. A recent study showed that BMAA has a significant inhibitory effect on the oxidative stress enzymes in C. demersum. Therefore, the toxicological effects on selected plants were investigated by a range of biochemical enzyme assays in order to establish the plant stress response to exogenous BMAA. The inhibition of antioxidant enzymes upon exposure of N. officinale to BMAA through the growth medium was observed. The inhibition of antioxidant defence enzymes by BMAA correlated with the BMAA bioaccumulation in N. officinale. Further investigations are needed to analyze the uptake, accumulation, and ecotoxicology of BMAA in other crop plants, and to examine the fate of BMAA in these plants particularly its distribution and metabolism.
- Full Text:
- Date Issued: 2010
- Authors: Niyonzima, Francois Niyongabo
- Date: 2010
- Subjects: Cyanobacteria , Environmental toxicology
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10312 , http://hdl.handle.net/10948/1475 , Cyanobacteria , Environmental toxicology
- Description: Cyanobacteria are known to produce a variety of toxic compounds. β-N-methylamino-L-alanine (BMAA) is one of the neurotoxins produced by most cyanobacteria. BMAA has been implicated in amyotrophic lateral sclerosis / Parkinsonism dementia complex (ALS / PDC) and was suggested to contribute to this pathology after biomagnification and slow release of BMAA from a protein associated form. The uptake and accumulation of BMAA by the aquatic macrophyte Ceratophyllum demersum has recently been shown, but the consumption of aquatic macrophytes by humans is not typical. The uptake by, and accumulation in, crop plants (Nasturtium officinale and Daucus carota) was therefore investigated so as to establish the existence of any risk to humans from the consumption of plants irrigated with water from dams with high cyanobacterial biomass and therefore high BMAA levels. After the exposure to the BMAA through the growth medium, BMAA had no effect on growth and development of N. officinale and D. carota. The uptake and bioaccumulation of BMAA was observed in N. officinale and D. carota, and was found to be concentration-dependent. Both free and bound cellular BMAA was detected following BMAA exposure through the growth medium. The photosynthetic apparatus of N. officinale was not significantly damaged. The uptake and accumulation of BMAA in edible terrestrial plants may constitute another route of human exposure to BMAA; it may now be prudent to avoid spray irrigation of edible plants with waters from dams with high cyanobacterial biomass and therefore high BMAA levels. After uptake by plants, the cyanotoxins may induce oxidative stress. A recent study showed that BMAA has a significant inhibitory effect on the oxidative stress enzymes in C. demersum. Therefore, the toxicological effects on selected plants were investigated by a range of biochemical enzyme assays in order to establish the plant stress response to exogenous BMAA. The inhibition of antioxidant enzymes upon exposure of N. officinale to BMAA through the growth medium was observed. The inhibition of antioxidant defence enzymes by BMAA correlated with the BMAA bioaccumulation in N. officinale. Further investigations are needed to analyze the uptake, accumulation, and ecotoxicology of BMAA in other crop plants, and to examine the fate of BMAA in these plants particularly its distribution and metabolism.
- Full Text:
- Date Issued: 2010
Bioethanol production from waste paper through fungal biotechnology
- Authors: Voigt, Paul George
- Date: 2010
- Subjects: Biomass energy , Cellulose -- Biodegradation , Waste paper -- Recycling , Biomass chemicals -- Economic aspects , Renewable energy sources , Fungi -- Biotechnology , Enzymes -- Biotechnology
- Language: English
- Type: Thesis , MSc , Masters
- Identifier: vital:3861 , http://hdl.handle.net/10962/d1013447
- Description: Bioethanol is likely to be a large contributor to the fuel sector of industry in the near future. Current research trends are geared towards utilizing food crops as substrate for bioethanol fermentation; however, this is the source of much controversy. Utilizing food crops for fuel purposes is anticipated to cause massive food shortages worldwide. Cellulose is the most abundant renewable resource on earth and is subject to a wide array of scientific study in order to utilize the glucose contained within it. Waste paper has a high degree of cellulose associated with it, which makes it an ideal target for cellulose biotechnology with the ultimate end goal of bioethanol production. This study focussed on producing the necessary enzymes to hydrolyse the cellulose found in waste paper and using the sugars produced to produce ethanol. The effects of various printing inks had on the production of sugars and the total envirorunental impact of the effluents produced during the production line were also examined. It was found that the fungus Trichoderma longibrachiatum DSM 769 grown in Mandel's medium with waste newspaper as the sole carbon source at 28 °C for 6 days produced extracellular cellulase enzymes with an activity of 0.203 ± 0.009 FPU.ml⁻¹, significantly higher activity as compared to other paper sources. This extracellular cellulase was used to hydrolyse waste newspaper and office paper, with office paper yielding the highest degree of sugar production with an end concentration of 5.80 ± 0.19 g/1 at 40 °C. Analysis by HPLC showed that although glucose was the major product at 4.35 ± 0.12 g/1, cellobiose was also produced in appreciable amounts (1.97 ± 0.71 g/1). The sugar solution was used as a substrate for Saccharomyces cerevisiae DSM 1333 and ethanol was produced at a level of 1.79 ± 0.26 g/1, the presence of which was confirmed by a 600 MHz NMR spectrum. It was found that cellobiose was not fermented by this strain of S. cerevisiae. Certain components of inks (the PAHs phenanthrene and naphthalene) were found to have a slight inhibitory effect (approximately 15% decrease) on the cellulase enzymes at very high concentrations (approximately 600 μg/1 in aqueous medium), while anthracene had no effect. Whole newsprint ink was shown not to sorb glucose. The environmental analysis of the effluents produced showed that in order for the effluents to be discharged into an aqueous ecosystem they would have to be diluted up to 200 times. They were also shown to have the potential to cause severe machinery damage if reused without proper treatment.
- Full Text:
- Date Issued: 2010
- Authors: Voigt, Paul George
- Date: 2010
- Subjects: Biomass energy , Cellulose -- Biodegradation , Waste paper -- Recycling , Biomass chemicals -- Economic aspects , Renewable energy sources , Fungi -- Biotechnology , Enzymes -- Biotechnology
- Language: English
- Type: Thesis , MSc , Masters
- Identifier: vital:3861 , http://hdl.handle.net/10962/d1013447
- Description: Bioethanol is likely to be a large contributor to the fuel sector of industry in the near future. Current research trends are geared towards utilizing food crops as substrate for bioethanol fermentation; however, this is the source of much controversy. Utilizing food crops for fuel purposes is anticipated to cause massive food shortages worldwide. Cellulose is the most abundant renewable resource on earth and is subject to a wide array of scientific study in order to utilize the glucose contained within it. Waste paper has a high degree of cellulose associated with it, which makes it an ideal target for cellulose biotechnology with the ultimate end goal of bioethanol production. This study focussed on producing the necessary enzymes to hydrolyse the cellulose found in waste paper and using the sugars produced to produce ethanol. The effects of various printing inks had on the production of sugars and the total envirorunental impact of the effluents produced during the production line were also examined. It was found that the fungus Trichoderma longibrachiatum DSM 769 grown in Mandel's medium with waste newspaper as the sole carbon source at 28 °C for 6 days produced extracellular cellulase enzymes with an activity of 0.203 ± 0.009 FPU.ml⁻¹, significantly higher activity as compared to other paper sources. This extracellular cellulase was used to hydrolyse waste newspaper and office paper, with office paper yielding the highest degree of sugar production with an end concentration of 5.80 ± 0.19 g/1 at 40 °C. Analysis by HPLC showed that although glucose was the major product at 4.35 ± 0.12 g/1, cellobiose was also produced in appreciable amounts (1.97 ± 0.71 g/1). The sugar solution was used as a substrate for Saccharomyces cerevisiae DSM 1333 and ethanol was produced at a level of 1.79 ± 0.26 g/1, the presence of which was confirmed by a 600 MHz NMR spectrum. It was found that cellobiose was not fermented by this strain of S. cerevisiae. Certain components of inks (the PAHs phenanthrene and naphthalene) were found to have a slight inhibitory effect (approximately 15% decrease) on the cellulase enzymes at very high concentrations (approximately 600 μg/1 in aqueous medium), while anthracene had no effect. Whole newsprint ink was shown not to sorb glucose. The environmental analysis of the effluents produced showed that in order for the effluents to be discharged into an aqueous ecosystem they would have to be diluted up to 200 times. They were also shown to have the potential to cause severe machinery damage if reused without proper treatment.
- Full Text:
- Date Issued: 2010
Broadening the tax base: a case for the informal real estate sector in Zambia
- Authors: Siame, Chilengwe George
- Date: 2010
- Subjects: Real property and taxation -- Zambia Tax administration and procedure -- Zambia Rental housing -- Taxation -- Law and legislation -- Zambia Informal sector (Economics) -- Taxation -- Law and legislation -- Zambia
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:732 , http://hdl.handle.net/10962/d1003852
- Description: The main objective of the study was to analyze the potential tax collection from the informal rental housing market in Zambia, using household level rental housing data collected for the Lusaka Urban District by the Central Statistical Office (CSO) as a basis for computation and extrapolation to the national level. This data was used to analyze household monthly expenditure on housing (rent), the total number of households in rented accommodation, and the tax regime applicable on rental income, to estimate the potential tax revenue that could be realized from this emerging sector. The estimates indicate that about K9.7 billion revenue could be collected on income from rental housing in Lusaka Urban District alone and a total of K83 billion nationally per annum. This represents about 0.4 percent of the country’s GDP in 2007. Compliance needs to be improved and legislation revised to ensure that the landlords are compelled to remit tax to the Zambia Revenue Authority. The current legislation makes enforcement and compliance difficult as it places the statutory tax burden on tenants, who are very mobile. It is, therefore, recommended that the landlord is made responsible for the payment of taxes due on rental income and that any compliance requirements be enforced against the real estate/property that is generating the income. This study also examines the performance of the presumptive taxation regime in Zambia The study uses data from the Zambia Revenue Authority on revenue collection from presumptive taxes which were introduced to capture income from the informal sectors. The presumptive taxes already introduced in Zambia include: base tax, advance income tax and turnover tax for minibuses and taxi operators. To analyze the performance of the presumptive tax regime, the study utilizes data on imports made by those not registered for taxes, to estimate how much revenue could be generated by imposing a 3 percent turnover tax on the value of their imports at importation. The analysis shows that the Zambia Revenue Authority increased revenue collection from K5.3 billion in 2004 to K33.5 billion in 2007. This improvement in revenue collection is far below the potential, however, which is estimated at over K501 billion on imports of unregistered traders alone. To collect this revenue and expand the tax base, the tax authority needs to improve the administration of advance income tax on unregistered importers, and raise the advance income tax rate to a level where the importer is indifferent between paying the advance tax at the border and paying turnover tax inland.
- Full Text:
- Date Issued: 2010
- Authors: Siame, Chilengwe George
- Date: 2010
- Subjects: Real property and taxation -- Zambia Tax administration and procedure -- Zambia Rental housing -- Taxation -- Law and legislation -- Zambia Informal sector (Economics) -- Taxation -- Law and legislation -- Zambia
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:732 , http://hdl.handle.net/10962/d1003852
- Description: The main objective of the study was to analyze the potential tax collection from the informal rental housing market in Zambia, using household level rental housing data collected for the Lusaka Urban District by the Central Statistical Office (CSO) as a basis for computation and extrapolation to the national level. This data was used to analyze household monthly expenditure on housing (rent), the total number of households in rented accommodation, and the tax regime applicable on rental income, to estimate the potential tax revenue that could be realized from this emerging sector. The estimates indicate that about K9.7 billion revenue could be collected on income from rental housing in Lusaka Urban District alone and a total of K83 billion nationally per annum. This represents about 0.4 percent of the country’s GDP in 2007. Compliance needs to be improved and legislation revised to ensure that the landlords are compelled to remit tax to the Zambia Revenue Authority. The current legislation makes enforcement and compliance difficult as it places the statutory tax burden on tenants, who are very mobile. It is, therefore, recommended that the landlord is made responsible for the payment of taxes due on rental income and that any compliance requirements be enforced against the real estate/property that is generating the income. This study also examines the performance of the presumptive taxation regime in Zambia The study uses data from the Zambia Revenue Authority on revenue collection from presumptive taxes which were introduced to capture income from the informal sectors. The presumptive taxes already introduced in Zambia include: base tax, advance income tax and turnover tax for minibuses and taxi operators. To analyze the performance of the presumptive tax regime, the study utilizes data on imports made by those not registered for taxes, to estimate how much revenue could be generated by imposing a 3 percent turnover tax on the value of their imports at importation. The analysis shows that the Zambia Revenue Authority increased revenue collection from K5.3 billion in 2004 to K33.5 billion in 2007. This improvement in revenue collection is far below the potential, however, which is estimated at over K501 billion on imports of unregistered traders alone. To collect this revenue and expand the tax base, the tax authority needs to improve the administration of advance income tax on unregistered importers, and raise the advance income tax rate to a level where the importer is indifferent between paying the advance tax at the border and paying turnover tax inland.
- Full Text:
- Date Issued: 2010
Brood cycles in queenless colonies of Apis mellifera capensis
- Authors: Crous, Kendall Lauren
- Date: 2010
- Subjects: Cape honeybee , Bee culture -- Queen rearing , Bees -- Breeding
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5652 , http://hdl.handle.net/10962/d1005335 , Cape honeybee , Bee culture -- Queen rearing , Bees -- Breeding
- Description: In a honeybee colony, the loss of a queen is considered to be a serious occurrence and, if a new queen is not produced, ultimately doomed. However, in colonies of Apis mellifera capensis (Cape honeybees), numerous pathways are available for a colony which unexpectedly losses a queen. At the onset of this experiment, four colonies of A. m. capensis were dequeened. Following this photographs of all brood frames in each colony were taken and the contents of the cells analysed. Cells were chosen at random but once selected were repeatedly analysed for the duration of the experiment. The contents of a total of 44 888 individual cells were analysed. Any queen cells constructed during the sampling period were removed, maintaining a queenless state. In each colony, as predicted, the removal of the queen evoked a variety of responses in an attempt to rectify the sudden loss. However, ultimately three of the four colonies absconded, leaving little by way of stores. Three of the four colonies initially attempted to rear a new queen while one colony was immediately invaded by a presumed foreign queen and hence any attempt at queen cell construction ceased. An increased number of queen cells in the swarm position were recorded in all colonies. The invasion of a colony by a foreign queen was considered to be a new pathway available for queenless colonies of A.m capensis. Worker policing and suspected brood cannibalism was prevalent in all sampled colonies yet in addition, the transfer of eggs and larvae from cell to cell was also observed which may have increased the suspected cases of policing and cannibalism. It was unclear whether an egg or larva had been consumed or simply moved to another cell on the brood frame. All colonies contained eggs from laying workers to varying degrees, based on the length of each individual sampling period which varied between colonies due to differences in absconding dates. A steady breakdown in the effectiveness of the division of labour amongst the worker bees was observed in each of the colonies highlighting the vital role of a queen. This breakdown was clearly seen in the reduction in general housekeeping within a colony. An increase in stores indicated a possible increase in the number of forager bees, thereby reducing the number of worker bees available for other duties. Pathways available to broodright colonies and strategies used following sudden queen loss are discussed.
- Full Text:
- Date Issued: 2010
- Authors: Crous, Kendall Lauren
- Date: 2010
- Subjects: Cape honeybee , Bee culture -- Queen rearing , Bees -- Breeding
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5652 , http://hdl.handle.net/10962/d1005335 , Cape honeybee , Bee culture -- Queen rearing , Bees -- Breeding
- Description: In a honeybee colony, the loss of a queen is considered to be a serious occurrence and, if a new queen is not produced, ultimately doomed. However, in colonies of Apis mellifera capensis (Cape honeybees), numerous pathways are available for a colony which unexpectedly losses a queen. At the onset of this experiment, four colonies of A. m. capensis were dequeened. Following this photographs of all brood frames in each colony were taken and the contents of the cells analysed. Cells were chosen at random but once selected were repeatedly analysed for the duration of the experiment. The contents of a total of 44 888 individual cells were analysed. Any queen cells constructed during the sampling period were removed, maintaining a queenless state. In each colony, as predicted, the removal of the queen evoked a variety of responses in an attempt to rectify the sudden loss. However, ultimately three of the four colonies absconded, leaving little by way of stores. Three of the four colonies initially attempted to rear a new queen while one colony was immediately invaded by a presumed foreign queen and hence any attempt at queen cell construction ceased. An increased number of queen cells in the swarm position were recorded in all colonies. The invasion of a colony by a foreign queen was considered to be a new pathway available for queenless colonies of A.m capensis. Worker policing and suspected brood cannibalism was prevalent in all sampled colonies yet in addition, the transfer of eggs and larvae from cell to cell was also observed which may have increased the suspected cases of policing and cannibalism. It was unclear whether an egg or larva had been consumed or simply moved to another cell on the brood frame. All colonies contained eggs from laying workers to varying degrees, based on the length of each individual sampling period which varied between colonies due to differences in absconding dates. A steady breakdown in the effectiveness of the division of labour amongst the worker bees was observed in each of the colonies highlighting the vital role of a queen. This breakdown was clearly seen in the reduction in general housekeeping within a colony. An increase in stores indicated a possible increase in the number of forager bees, thereby reducing the number of worker bees available for other duties. Pathways available to broodright colonies and strategies used following sudden queen loss are discussed.
- Full Text:
- Date Issued: 2010
Building a semantic web-based e-health component for a multipurpose communication centre
- Authors: Hlungulu, Bulumko
- Date: 2010
- Subjects: Rural development -- South Africa -- Eastern Cape , Information technology -- South Africa -- Eastern Cape , Internet in medicine -- South Africa -- Eastern Cape , Telecommunication in medicine -- South Africa -- Eastern Cape , Health -- Computer network resources
- Language: English
- Type: Thesis , Masters , MSc (Computer Science)
- Identifier: vital:11380 , http://hdl.handle.net/10353/374 , Rural development -- South Africa -- Eastern Cape , Information technology -- South Africa -- Eastern Cape , Internet in medicine -- South Africa -- Eastern Cape , Telecommunication in medicine -- South Africa -- Eastern Cape , Health -- Computer network resources
- Description: Rural communities have limited access to health information which is made available on the internet. This is due to poor infrastructure (i.e., lack of clinics or Internet access) and that gives them problems in accessing information within the domain of health. The availability of Information and Communication Technologies (ICTs) in a rural community can provide the community with a number of beneficial solutions to their problems as they maximize the potential of knowledge sharing and delivery. This research seeks to make use of ICTs deployed in the community of Dwesa, in order to contribute to improving the health standards of the community. It seeks to accomplish this by carrying out an investigation and literature review with the aim of understanding health knowledge sharing dynamics in the context of marginalized communities. The knowledge acquired will then be used in the development and implementation of a semantic web-based e-Health portal as part of the Siyakhula Living Lab (SLL) project. This portal will share and deliver western medical knowledge, traditional knowledge and indigenous knowledge. This research seeks to make use of a combination of Free and/or Open Sources Software in developing the portal to make it affordable to the community.
- Full Text:
- Date Issued: 2010
- Authors: Hlungulu, Bulumko
- Date: 2010
- Subjects: Rural development -- South Africa -- Eastern Cape , Information technology -- South Africa -- Eastern Cape , Internet in medicine -- South Africa -- Eastern Cape , Telecommunication in medicine -- South Africa -- Eastern Cape , Health -- Computer network resources
- Language: English
- Type: Thesis , Masters , MSc (Computer Science)
- Identifier: vital:11380 , http://hdl.handle.net/10353/374 , Rural development -- South Africa -- Eastern Cape , Information technology -- South Africa -- Eastern Cape , Internet in medicine -- South Africa -- Eastern Cape , Telecommunication in medicine -- South Africa -- Eastern Cape , Health -- Computer network resources
- Description: Rural communities have limited access to health information which is made available on the internet. This is due to poor infrastructure (i.e., lack of clinics or Internet access) and that gives them problems in accessing information within the domain of health. The availability of Information and Communication Technologies (ICTs) in a rural community can provide the community with a number of beneficial solutions to their problems as they maximize the potential of knowledge sharing and delivery. This research seeks to make use of ICTs deployed in the community of Dwesa, in order to contribute to improving the health standards of the community. It seeks to accomplish this by carrying out an investigation and literature review with the aim of understanding health knowledge sharing dynamics in the context of marginalized communities. The knowledge acquired will then be used in the development and implementation of a semantic web-based e-Health portal as part of the Siyakhula Living Lab (SLL) project. This portal will share and deliver western medical knowledge, traditional knowledge and indigenous knowledge. This research seeks to make use of a combination of Free and/or Open Sources Software in developing the portal to make it affordable to the community.
- Full Text:
- Date Issued: 2010
Business journalism ethics in Africa: a comparative study of newsrooms in South Africa, Kenya and Zimbabwe
- Authors: Mare, Admire
- Date: 2010
- Subjects: Journalism, Commercial Journalistic ethics Journalism, Commercial -- South Africa Journalism, Commercial -- Kenya Journalism, Commercial -- Zimbabwe Business Day (South Africa) Business Daily (Kenya) Financial Gazette (Zimbabwe)
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3458 , http://hdl.handle.net/10962/d1002912
- Description: This study provides an insight into the state of business journalism ethics in Africa, firstly through an examination of newsroom ethical policies and secondly through an exploration of the way in which African business journalists negotiate ethical decision-making in their day-to-day news processing practices. Thirdly, it examines how the three African media organisations have responded in their newsroom policies and practices to the debates on the Africanisation of journalism ethics. In order to collect data, the researcher employed document analysis, semi-structured questionnaires and in-depth interviews. Three financial newspapers namely: Business Day in South Africa, Business Daily in Kenya and Financial Gazette in Zimbabwe were purposively chosen. In these African countries, business journalism has been steadily growing since the late 1960s, fuelled by the presence of robust stock exchanges, making the issue of business journalism ethics of central importance. Grounded in the sociology of news production paradigm, Bourdieu’s journalistic field theory and debates on Africanisation of journalism ethics, this study identifies three major issues. First, the research found that while all three newspapers had clear ethical guidelines in place, and editors and journalists recognised the importance of ethical behaviour, ethical practice did not always follow. A disconnect exists between words (codes of ethics) and actions (practice) especially in Kenya and Zimbabwe, where business journalists are more susceptible to economic and political pressures. The argument is ethical considerations notwithstanding, people need to survive. This is largely due to the precarious economic basis of news organisations, lack of effective monitoring, and a pervasive culture of unethical behaviour at some sites. Second, the study also shows that institutional factors such as advertising, powerful news sources and interference from senior management make ethical business journalism difficult to practice. Third, Africanisation remains an academic issue with little movement towards that direction in most newsrooms studied. The findings of this study demonstrate that business editors in African newsrooms are confused on what ‘Africanisation’ entails especially given their shared view that journalism practices are universal. It recommends that business journalism codes of ethics informed by African values are long overdue. In terms of enforcement and monitoring of codes, it is important to use compliance officers or ombudsperson and periodically run in-house refresher courses on ethics and professionalism. It is imperative that the financial press improve the working conditions of its employees in order to lessen incidences of corruption which are threatening the credibility of media content and media organisation themselves.
- Full Text:
- Date Issued: 2010
- Authors: Mare, Admire
- Date: 2010
- Subjects: Journalism, Commercial Journalistic ethics Journalism, Commercial -- South Africa Journalism, Commercial -- Kenya Journalism, Commercial -- Zimbabwe Business Day (South Africa) Business Daily (Kenya) Financial Gazette (Zimbabwe)
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3458 , http://hdl.handle.net/10962/d1002912
- Description: This study provides an insight into the state of business journalism ethics in Africa, firstly through an examination of newsroom ethical policies and secondly through an exploration of the way in which African business journalists negotiate ethical decision-making in their day-to-day news processing practices. Thirdly, it examines how the three African media organisations have responded in their newsroom policies and practices to the debates on the Africanisation of journalism ethics. In order to collect data, the researcher employed document analysis, semi-structured questionnaires and in-depth interviews. Three financial newspapers namely: Business Day in South Africa, Business Daily in Kenya and Financial Gazette in Zimbabwe were purposively chosen. In these African countries, business journalism has been steadily growing since the late 1960s, fuelled by the presence of robust stock exchanges, making the issue of business journalism ethics of central importance. Grounded in the sociology of news production paradigm, Bourdieu’s journalistic field theory and debates on Africanisation of journalism ethics, this study identifies three major issues. First, the research found that while all three newspapers had clear ethical guidelines in place, and editors and journalists recognised the importance of ethical behaviour, ethical practice did not always follow. A disconnect exists between words (codes of ethics) and actions (practice) especially in Kenya and Zimbabwe, where business journalists are more susceptible to economic and political pressures. The argument is ethical considerations notwithstanding, people need to survive. This is largely due to the precarious economic basis of news organisations, lack of effective monitoring, and a pervasive culture of unethical behaviour at some sites. Second, the study also shows that institutional factors such as advertising, powerful news sources and interference from senior management make ethical business journalism difficult to practice. Third, Africanisation remains an academic issue with little movement towards that direction in most newsrooms studied. The findings of this study demonstrate that business editors in African newsrooms are confused on what ‘Africanisation’ entails especially given their shared view that journalism practices are universal. It recommends that business journalism codes of ethics informed by African values are long overdue. In terms of enforcement and monitoring of codes, it is important to use compliance officers or ombudsperson and periodically run in-house refresher courses on ethics and professionalism. It is imperative that the financial press improve the working conditions of its employees in order to lessen incidences of corruption which are threatening the credibility of media content and media organisation themselves.
- Full Text:
- Date Issued: 2010
C3TO : a scalable architecture for mobile chat based tutoring
- Authors: Butgereit, Laura Lee
- Date: 2010
- Subjects: Intelligent tutoring systems , Instructional systems -- Design
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9746 , http://hdl.handle.net/10948/1511 , Intelligent tutoring systems , Instructional systems -- Design
- Description: C³TO (Chatter Call Centre/Tutoring Online) is a scalable architecture to support mobile online tutoring using chat protocols over cell phones. It is the scalability of this architecture which is the primary focus of this dissertation. Much has been written lamenting the state of mathematics education in South Africa. It is not a pretty story. In order to help solve this mathematical crisis, the “Dr Math” research project was started in January, 2007. “Dr Math” strove to assist school pupils with their mathematics homework by providing access to tutors from a nearby university to help them. The school pupils used MXit on their cell phones and the tutors used normal computer workstations. The original “Dr Math” research project expected no more than twenty to thirty school pupils to participate. Unexpectedly thousands of school pupils started asking “Dr Math” to assist them with their mathematics homework. The original software could not scale. The original software could not cater for the thousands of pupils needing help. The scalability problems which existed in the original “Dr Math” project included: hardware scalability issues, software scalability problems, lack of physical office space for tutors, and tutor time being wasted by trivial questions. C³TO tackled these scalability concerns using an innovative three level approach by implementing a technological feature level, a tactical feature level, and a strategic feature level in the C³TO architecture. The technological level included specific components, utilities, and platforms which promoted scalability. The technological level provided the basic building blocks with which to construct a scalable architecture. The tactical level arranged the basic building blocks of the technological level into a scalable architecture. The tactical level provided short term solutions to scalability concerns by providing easy configurability and decision making. The strategic level attempted to answer the pupils questions before they actually arrived at the tutor thereby reducing the load on the human tutors. C³TO was extensively tested and evaluated. C³TO supported thousands of school pupils with their mathematics homework over a period of ten months. C³TO was used to support a small conference. C³TO was used to encourage people to volunteer their time in participation of Mandela Day. C³TO was used to support “Winter School” during the winter school holiday. In all these cases, C³TO proved itself to be scalable.
- Full Text:
- Date Issued: 2010
- Authors: Butgereit, Laura Lee
- Date: 2010
- Subjects: Intelligent tutoring systems , Instructional systems -- Design
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9746 , http://hdl.handle.net/10948/1511 , Intelligent tutoring systems , Instructional systems -- Design
- Description: C³TO (Chatter Call Centre/Tutoring Online) is a scalable architecture to support mobile online tutoring using chat protocols over cell phones. It is the scalability of this architecture which is the primary focus of this dissertation. Much has been written lamenting the state of mathematics education in South Africa. It is not a pretty story. In order to help solve this mathematical crisis, the “Dr Math” research project was started in January, 2007. “Dr Math” strove to assist school pupils with their mathematics homework by providing access to tutors from a nearby university to help them. The school pupils used MXit on their cell phones and the tutors used normal computer workstations. The original “Dr Math” research project expected no more than twenty to thirty school pupils to participate. Unexpectedly thousands of school pupils started asking “Dr Math” to assist them with their mathematics homework. The original software could not scale. The original software could not cater for the thousands of pupils needing help. The scalability problems which existed in the original “Dr Math” project included: hardware scalability issues, software scalability problems, lack of physical office space for tutors, and tutor time being wasted by trivial questions. C³TO tackled these scalability concerns using an innovative three level approach by implementing a technological feature level, a tactical feature level, and a strategic feature level in the C³TO architecture. The technological level included specific components, utilities, and platforms which promoted scalability. The technological level provided the basic building blocks with which to construct a scalable architecture. The tactical level arranged the basic building blocks of the technological level into a scalable architecture. The tactical level provided short term solutions to scalability concerns by providing easy configurability and decision making. The strategic level attempted to answer the pupils questions before they actually arrived at the tutor thereby reducing the load on the human tutors. C³TO was extensively tested and evaluated. C³TO supported thousands of school pupils with their mathematics homework over a period of ten months. C³TO was used to support a small conference. C³TO was used to encourage people to volunteer their time in participation of Mandela Day. C³TO was used to support “Winter School” during the winter school holiday. In all these cases, C³TO proved itself to be scalable.
- Full Text:
- Date Issued: 2010
Challenges facing health professionals in OR Tambo health district municipalities
- Authors: Mduba, Nomasomi Cynthia
- Date: 2010
- Subjects: Medical personnel -- South Africa -- Eastern Cape , Municipal services -- South Africa -- Eastern Cape , Performance -- Evaluation , Health facilities -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MPA
- Identifier: vital:11627 , http://hdl.handle.net/10353/278 , Medical personnel -- South Africa -- Eastern Cape , Municipal services -- South Africa -- Eastern Cape , Performance -- Evaluation , Health facilities -- South Africa -- Eastern Cape
- Description: My motivation to conduct this study was triggered by my exposure to the challenges which form the basis of this study. Being employed in the same environment as the respondents, it became natural for me to resolve to investigate the challenges facing these Health Professionals with the purpose of not only establishing what the challenges are but simultaneously propose remedial solutions to mitigate their impact. This study is both qualitative as well as quantitative to make sure that both the numerical as well as the social issues which impact these professionals‘ work were captured in the study. The assumptions from which the study moved were largely confirmed by the respondents. The recommendations which the researcher proposes to mitigate the challenges are informed by her own experience as well as the responses which were elicited from the respondents. While the study does contribute in a way to the body of knowledge, it is cautioned in the concluding chapter that recommendations made must be considered with this caution in mind as the study was limited to a specific environment – the OR Tambo District Health Municipality.
- Full Text:
- Date Issued: 2010
- Authors: Mduba, Nomasomi Cynthia
- Date: 2010
- Subjects: Medical personnel -- South Africa -- Eastern Cape , Municipal services -- South Africa -- Eastern Cape , Performance -- Evaluation , Health facilities -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MPA
- Identifier: vital:11627 , http://hdl.handle.net/10353/278 , Medical personnel -- South Africa -- Eastern Cape , Municipal services -- South Africa -- Eastern Cape , Performance -- Evaluation , Health facilities -- South Africa -- Eastern Cape
- Description: My motivation to conduct this study was triggered by my exposure to the challenges which form the basis of this study. Being employed in the same environment as the respondents, it became natural for me to resolve to investigate the challenges facing these Health Professionals with the purpose of not only establishing what the challenges are but simultaneously propose remedial solutions to mitigate their impact. This study is both qualitative as well as quantitative to make sure that both the numerical as well as the social issues which impact these professionals‘ work were captured in the study. The assumptions from which the study moved were largely confirmed by the respondents. The recommendations which the researcher proposes to mitigate the challenges are informed by her own experience as well as the responses which were elicited from the respondents. While the study does contribute in a way to the body of knowledge, it is cautioned in the concluding chapter that recommendations made must be considered with this caution in mind as the study was limited to a specific environment – the OR Tambo District Health Municipality.
- Full Text:
- Date Issued: 2010
Challenges in topside ionospheric modelling over South Africa
- Authors: Sibanda, Patrick
- Date: 2010
- Subjects: Ionospheric electron density -- South Africa Neural networks (Computer science) Atmosphere, Upper Ionosphere
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5453 , http://hdl.handle.net/10962/d1005238
- Description: This thesis creates a basic framework and provides the information necessary to create a more accurate description of the topside ionosphere in terms of the altitude variation of the electron density (Ne) over the South African region. The detailed overview of various topside ionospheric modelling techniques, with specific emphasis on their implications for the efforts to model the South African topside, provides a starting point towards achieving the goals. The novelty of the thesis lies in the investigation of the applicabilityof three different techniques to model the South African topside ionosphere: (1) The possibility of using Artificial Neural Network (ANN) techniques for empirical modelling of the topside ionosphere based on the available, however irregularly sampled, topside sounder measurements. The goal of this model was to test the ability of ANN techniques to capture the complex relationships between the various ionospheric variables using irregularly distributed measurements. While this technique is promising, the method did not show significant improvement over the International Reference Ionosphere (IRI) model results when compared with the actual measurements. (2) Application of the diffusive equilibrium theory. Although based on sound physics foundations, the method only operates on a generalised level leading to results that are not necessarily unique. Furthermore, the approach relies on many ionospheric variables as inputs which are derived from other models whose accuracy is not verified. (3) Attempts to complement the standard functional techniques, (Chapman, Epstein, Exponential and Parabolic), with Global Positioning System (GPS) and ionosonde measurements in an effort to provide deeper insights into the actual conditions within the ionosphere. The vertical Ne distribution is reconstructed by linking together the different aspects of the constituent ions and their transition height by considering how they influence the shape of the profile. While this approach has not been tested against actual measurements, results show that the method could be potentially useful for topside ionospheric studies. Due to the limitations of each technique reviewed, this thesis observes that the employment of an approach that incorporates both theoretical onsiderations and empirical aspects has the potential to lead to a more accurate characterisation of the topside ionospheric behaviour, and resulting in improved models in terms of reliability and forecasting ability. The point is made that a topside sounder mission for South Africa would provide the required measured topside ionospheric data and answer the many science questions that this region poses as well as solving a number of the limitations set out in this thesis.
- Full Text:
- Date Issued: 2010
- Authors: Sibanda, Patrick
- Date: 2010
- Subjects: Ionospheric electron density -- South Africa Neural networks (Computer science) Atmosphere, Upper Ionosphere
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5453 , http://hdl.handle.net/10962/d1005238
- Description: This thesis creates a basic framework and provides the information necessary to create a more accurate description of the topside ionosphere in terms of the altitude variation of the electron density (Ne) over the South African region. The detailed overview of various topside ionospheric modelling techniques, with specific emphasis on their implications for the efforts to model the South African topside, provides a starting point towards achieving the goals. The novelty of the thesis lies in the investigation of the applicabilityof three different techniques to model the South African topside ionosphere: (1) The possibility of using Artificial Neural Network (ANN) techniques for empirical modelling of the topside ionosphere based on the available, however irregularly sampled, topside sounder measurements. The goal of this model was to test the ability of ANN techniques to capture the complex relationships between the various ionospheric variables using irregularly distributed measurements. While this technique is promising, the method did not show significant improvement over the International Reference Ionosphere (IRI) model results when compared with the actual measurements. (2) Application of the diffusive equilibrium theory. Although based on sound physics foundations, the method only operates on a generalised level leading to results that are not necessarily unique. Furthermore, the approach relies on many ionospheric variables as inputs which are derived from other models whose accuracy is not verified. (3) Attempts to complement the standard functional techniques, (Chapman, Epstein, Exponential and Parabolic), with Global Positioning System (GPS) and ionosonde measurements in an effort to provide deeper insights into the actual conditions within the ionosphere. The vertical Ne distribution is reconstructed by linking together the different aspects of the constituent ions and their transition height by considering how they influence the shape of the profile. While this approach has not been tested against actual measurements, results show that the method could be potentially useful for topside ionospheric studies. Due to the limitations of each technique reviewed, this thesis observes that the employment of an approach that incorporates both theoretical onsiderations and empirical aspects has the potential to lead to a more accurate characterisation of the topside ionospheric behaviour, and resulting in improved models in terms of reliability and forecasting ability. The point is made that a topside sounder mission for South Africa would provide the required measured topside ionospheric data and answer the many science questions that this region poses as well as solving a number of the limitations set out in this thesis.
- Full Text:
- Date Issued: 2010
Characterisation of dissimilar friction stir welds between 5754 Aluminium alloy and C11000 copper
- Authors: Akinlabi, Esther Titilayo
- Date: 2010
- Subjects: Friction stir welding , Aluminum alloys , Copper alloys
- Language: English
- Type: Thesis , Doctoral , DTech
- Identifier: vital:9629 , http://hdl.handle.net/10948/1536 , Friction stir welding , Aluminum alloys , Copper alloys
- Description: Friction Stir Welding (FSW) is a solid state welding process invented and patented by The Welding Institute (TWI) in 1991, for joining ferrous and non-ferrous materials1. The FSW of Aluminium and its alloys has been commercialised; and recent interest is focused on joining dissimilar materials. However, in order to commercialise the process, research studies are required to characterise and establish process windows. This research work through material characterisation of the welded joints establishes a process window for the Friction Stir welding of 5754 Aluminium Alloy and C11000 Copper. Furthermore, preliminary studies83,85 on the FSW of aluminium and copper have revealed the presence of intermetallic compounds which are detrimental to the weld qualities. This research work is also aimed at establishing process parameters that will result in limited or no intermetallic formation in the weld. The joint integrity of the resulting welds will also be correlated with the input process parameters. Based on the preliminary investigations conducted, a final weld matrix consisting of twenty seven welds was produced by varying the rotational speed between 600 and 1200 rpm, and the feed rate between 50 and 300 mm/min using three different shoulder diameter tools – 15, 18 and 25 mm to compare the heat input into the welds and to achieve the best results. The welds were characterised through microstructural evaluation, tensile testing, microhardness profiling, X-Ray Diffraction analysis, electrical resistivity and statistical analysis – in order to establish the interrelationship between the process parameters and the weld qualities. viii Microstructural evaluation of the weld samples revealed that the interfacial regions are characterised by mixture layers of aluminium and copper; while 33 percent of the tensile samples are within the acceptable range (> 75 percent joint efficiency). High Vickers microhardness values were measured at the joint interfaces, which corresponded with the intermetallic compounds. The Energy Dispersive Spectroscopy analysis revealed the presence of thin layers of intermetallics in nanoscale at the interfacial regions. The diffractograms of the X-Ray Diffraction analysis showed small peaks for intermetallics in some of the welds. Low electrical resistivities were measured at the joint interfaces. The statistical analysis showed that the downward vertical force, (Fz) can significantly influence the resulting weld qualities. An overall summary of the analysis of the weld qualities - with respect to the shoulder diameter tools employed showed that the 18 mm shoulder diameter tool is most appropriate among the three shoulder diameters considered, and a process window of medium spindle speed of 950 rpm and low-to-medium feed rate between 50 and 150 mm/min is established for FSW of Aluminium and Copper. Welds produced at 1200 rpm and 300 mm/min with low heat input did not have intermetallics formed at the joint interface.
- Full Text:
- Date Issued: 2010
- Authors: Akinlabi, Esther Titilayo
- Date: 2010
- Subjects: Friction stir welding , Aluminum alloys , Copper alloys
- Language: English
- Type: Thesis , Doctoral , DTech
- Identifier: vital:9629 , http://hdl.handle.net/10948/1536 , Friction stir welding , Aluminum alloys , Copper alloys
- Description: Friction Stir Welding (FSW) is a solid state welding process invented and patented by The Welding Institute (TWI) in 1991, for joining ferrous and non-ferrous materials1. The FSW of Aluminium and its alloys has been commercialised; and recent interest is focused on joining dissimilar materials. However, in order to commercialise the process, research studies are required to characterise and establish process windows. This research work through material characterisation of the welded joints establishes a process window for the Friction Stir welding of 5754 Aluminium Alloy and C11000 Copper. Furthermore, preliminary studies83,85 on the FSW of aluminium and copper have revealed the presence of intermetallic compounds which are detrimental to the weld qualities. This research work is also aimed at establishing process parameters that will result in limited or no intermetallic formation in the weld. The joint integrity of the resulting welds will also be correlated with the input process parameters. Based on the preliminary investigations conducted, a final weld matrix consisting of twenty seven welds was produced by varying the rotational speed between 600 and 1200 rpm, and the feed rate between 50 and 300 mm/min using three different shoulder diameter tools – 15, 18 and 25 mm to compare the heat input into the welds and to achieve the best results. The welds were characterised through microstructural evaluation, tensile testing, microhardness profiling, X-Ray Diffraction analysis, electrical resistivity and statistical analysis – in order to establish the interrelationship between the process parameters and the weld qualities. viii Microstructural evaluation of the weld samples revealed that the interfacial regions are characterised by mixture layers of aluminium and copper; while 33 percent of the tensile samples are within the acceptable range (> 75 percent joint efficiency). High Vickers microhardness values were measured at the joint interfaces, which corresponded with the intermetallic compounds. The Energy Dispersive Spectroscopy analysis revealed the presence of thin layers of intermetallics in nanoscale at the interfacial regions. The diffractograms of the X-Ray Diffraction analysis showed small peaks for intermetallics in some of the welds. Low electrical resistivities were measured at the joint interfaces. The statistical analysis showed that the downward vertical force, (Fz) can significantly influence the resulting weld qualities. An overall summary of the analysis of the weld qualities - with respect to the shoulder diameter tools employed showed that the 18 mm shoulder diameter tool is most appropriate among the three shoulder diameters considered, and a process window of medium spindle speed of 950 rpm and low-to-medium feed rate between 50 and 150 mm/min is established for FSW of Aluminium and Copper. Welds produced at 1200 rpm and 300 mm/min with low heat input did not have intermetallics formed at the joint interface.
- Full Text:
- Date Issued: 2010
Chemical transformations and phytochemical studies of bioactive components from extracts of Rosmarinus officinalis L
- Authors: Okoh, Omobola Oluranti
- Date: 2010
- Subjects: Essences and essential oils , Rosmarinus , Lamiaceae , Solution (Chemistry) , Extractive distillation , Medicinal plants , Bioactive compounds
- Language: English
- Type: Thesis , Doctoral , PhD (Chemistry)
- Identifier: vital:11331 , http://hdl.handle.net/10353/354 , Essences and essential oils , Rosmarinus , Lamiaceae , Solution (Chemistry) , Extractive distillation , Medicinal plants , Bioactive compounds
- Description: Variations in the yield, chemical composition, antibacterial, and antioxidant properties of the essential oils of Rosmarinus officinalis L. cultivated in Alice, Eastern Cape of South Africa over a period of 12 months using the solvent-free microwave extraction and traditional hydrodistillation methods were evaluated. The GC-MS analyses of the essential oils revealed the presence of 33 compounds with 1,8-cineole, a-pinene, camphor, verbenone, bornyl acetate and camphene constituting about 80 percent of the oils throughout the period of investigation, with the solvent-free microwave extraction method generally yielding more of the major components than the hydrodistillation method. Each of the major components of the oils varied in quantity and quality of yield at different periods of the year. The method of extraction and time of harvest are of importance to the quantity and quality of essential oil of Rosmarinus officinalis. Higher amounts of oxygenated monoterpenes such as borneol, camphor, terpene- 4-ol, linalool, a-terpeneol were present in the oil of SFME in comparison with HD. However, HD oil contained more monoterpene hydrocarbons such as a-pinene, camphene, β-pinene, myrcene, a-phellanderene, 1,8-cineole, trans- β-ocimene, γ-teprinene, and cis-sabinene hydrate than SFME extracted oil. Accumulation of monoterpene alcohols and ketones was observed during maturation process of Rosmarinus leaves. Quantitative evaluation of antibacterial activity, minimum inhibitory concentration values were determined using a serial microplate dilution method. The essential oils obtained using both methods of extraction were active against all the bacteria tested at a concentration of 10 mg mL-1. The minimum inhibitory concentrations for the SFME extracted oils ranged between 0.23 and 1.88 mg mL-1, while those of the HD extracted oils varied between 0.94 and 7.5 mg mL-1, thus suggesting that the oil obtained by solvent free microwave extraction was more active against bacteria than the oil obtained through hydrodistillation. The antioxidant and free radical scavenging activity of the obtained oils were tested by means of 1,1-diphenyl-2-picrylhydrazyl radical (DPPH+) assay and β- carotene bleaching test. In the DPPH+ assay, while the free radical scavenging activity of the oil obtained by SFME method showed percentage inhibitions of between 48.8 percent and 67 percent, the HD derived oil showed inhibitions of between 52.2 percent and 65.30 percent at concentrations of 0.33, 0.50 and 1.0 mg mL-1, respectively. In the β-carotene bleaching assay, the percentage inhibition increased with increasing concentration of both oils with a higher antioxidant activity of the oil obtained through the SFME than the HD method. Thin layer chromatography (TLC) was used to analyze the chemical composition of the extracts using three eluent solvent systems of varying polarities i. e. CEF, BEA and EMW and sprayed with vanillin-sulfuric acid. The chemical composition of the different extracts was similar with the exception of methanol and water extracts which had only one or two visible compounds after treating with vanillin-spray reagent. To evaluate the number of antibacterial compounds present in the fractions, bioautography was used against two most important nosocomial microorganisms. S. aureus (Gram positive) and E. coli (Gram negative). Nearly all the crude serial extraction fractions contained compounds that inhibited the growth of E. coli. The hexane extract had the most lines of inhibition followed by ethyl acetate. Bioassay-guided fractionation against E. coli was used to isolate antibacterial compounds. The largest number of antibacterial compounds occurred in the hexane fraction. Furthermore we tried to complete the characterization by extracting and studying other biologically important plant metabolites such as phenolic compounds to evaluate the antioxidant capacity of Rosmarinus extracts.
- Full Text:
- Date Issued: 2010
- Authors: Okoh, Omobola Oluranti
- Date: 2010
- Subjects: Essences and essential oils , Rosmarinus , Lamiaceae , Solution (Chemistry) , Extractive distillation , Medicinal plants , Bioactive compounds
- Language: English
- Type: Thesis , Doctoral , PhD (Chemistry)
- Identifier: vital:11331 , http://hdl.handle.net/10353/354 , Essences and essential oils , Rosmarinus , Lamiaceae , Solution (Chemistry) , Extractive distillation , Medicinal plants , Bioactive compounds
- Description: Variations in the yield, chemical composition, antibacterial, and antioxidant properties of the essential oils of Rosmarinus officinalis L. cultivated in Alice, Eastern Cape of South Africa over a period of 12 months using the solvent-free microwave extraction and traditional hydrodistillation methods were evaluated. The GC-MS analyses of the essential oils revealed the presence of 33 compounds with 1,8-cineole, a-pinene, camphor, verbenone, bornyl acetate and camphene constituting about 80 percent of the oils throughout the period of investigation, with the solvent-free microwave extraction method generally yielding more of the major components than the hydrodistillation method. Each of the major components of the oils varied in quantity and quality of yield at different periods of the year. The method of extraction and time of harvest are of importance to the quantity and quality of essential oil of Rosmarinus officinalis. Higher amounts of oxygenated monoterpenes such as borneol, camphor, terpene- 4-ol, linalool, a-terpeneol were present in the oil of SFME in comparison with HD. However, HD oil contained more monoterpene hydrocarbons such as a-pinene, camphene, β-pinene, myrcene, a-phellanderene, 1,8-cineole, trans- β-ocimene, γ-teprinene, and cis-sabinene hydrate than SFME extracted oil. Accumulation of monoterpene alcohols and ketones was observed during maturation process of Rosmarinus leaves. Quantitative evaluation of antibacterial activity, minimum inhibitory concentration values were determined using a serial microplate dilution method. The essential oils obtained using both methods of extraction were active against all the bacteria tested at a concentration of 10 mg mL-1. The minimum inhibitory concentrations for the SFME extracted oils ranged between 0.23 and 1.88 mg mL-1, while those of the HD extracted oils varied between 0.94 and 7.5 mg mL-1, thus suggesting that the oil obtained by solvent free microwave extraction was more active against bacteria than the oil obtained through hydrodistillation. The antioxidant and free radical scavenging activity of the obtained oils were tested by means of 1,1-diphenyl-2-picrylhydrazyl radical (DPPH+) assay and β- carotene bleaching test. In the DPPH+ assay, while the free radical scavenging activity of the oil obtained by SFME method showed percentage inhibitions of between 48.8 percent and 67 percent, the HD derived oil showed inhibitions of between 52.2 percent and 65.30 percent at concentrations of 0.33, 0.50 and 1.0 mg mL-1, respectively. In the β-carotene bleaching assay, the percentage inhibition increased with increasing concentration of both oils with a higher antioxidant activity of the oil obtained through the SFME than the HD method. Thin layer chromatography (TLC) was used to analyze the chemical composition of the extracts using three eluent solvent systems of varying polarities i. e. CEF, BEA and EMW and sprayed with vanillin-sulfuric acid. The chemical composition of the different extracts was similar with the exception of methanol and water extracts which had only one or two visible compounds after treating with vanillin-spray reagent. To evaluate the number of antibacterial compounds present in the fractions, bioautography was used against two most important nosocomial microorganisms. S. aureus (Gram positive) and E. coli (Gram negative). Nearly all the crude serial extraction fractions contained compounds that inhibited the growth of E. coli. The hexane extract had the most lines of inhibition followed by ethyl acetate. Bioassay-guided fractionation against E. coli was used to isolate antibacterial compounds. The largest number of antibacterial compounds occurred in the hexane fraction. Furthermore we tried to complete the characterization by extracting and studying other biologically important plant metabolites such as phenolic compounds to evaluate the antioxidant capacity of Rosmarinus extracts.
- Full Text:
- Date Issued: 2010
Citrus, labour and gender in the Eastern Cape: the case of the Kat River area
- Mzitshi, Zoleka Alice Florence
- Authors: Mzitshi, Zoleka Alice Florence
- Date: 2010
- Subjects: Citrus -- South Africa -- Eastern Cape , Citrus , Working class women -- South Africa -- Eastern Cape , Sex role -- South Africa -- Eastern Cape , Citrus fruit industry -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc (Geography)
- Identifier: vital:11511 , http://hdl.handle.net/10353/379 , Citrus -- South Africa -- Eastern Cape , Citrus , Working class women -- South Africa -- Eastern Cape , Sex role -- South Africa -- Eastern Cape , Citrus fruit industry -- South Africa -- Eastern Cape
- Description: Agriculture plays a significant role in South Africa’s export earning and in providing employment opportunities. Amongst the major agricultural crops is citrus. Within the context of postmodern and feminist geographies and utilizing the intensive research design, this thesis discusses citrus production with a focus on growers and black women workers in the Kat River Valley area in Fort Beaufort, Eastern Cape. The thesis also explores the challenges and implications of restructuring within agriculture for growers, cooperatives and labour within the citrus industry. It is argued that whilst legislation related to labour and tenure within agriculture has changed since the mid-1990s, power relations in the citrus industry have remained firmly entrenched. Consequently, the flexible labour strategies that the citrus farmers adopted have had serious consequences for women worker
- Full Text:
- Date Issued: 2010
- Authors: Mzitshi, Zoleka Alice Florence
- Date: 2010
- Subjects: Citrus -- South Africa -- Eastern Cape , Citrus , Working class women -- South Africa -- Eastern Cape , Sex role -- South Africa -- Eastern Cape , Citrus fruit industry -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc (Geography)
- Identifier: vital:11511 , http://hdl.handle.net/10353/379 , Citrus -- South Africa -- Eastern Cape , Citrus , Working class women -- South Africa -- Eastern Cape , Sex role -- South Africa -- Eastern Cape , Citrus fruit industry -- South Africa -- Eastern Cape
- Description: Agriculture plays a significant role in South Africa’s export earning and in providing employment opportunities. Amongst the major agricultural crops is citrus. Within the context of postmodern and feminist geographies and utilizing the intensive research design, this thesis discusses citrus production with a focus on growers and black women workers in the Kat River Valley area in Fort Beaufort, Eastern Cape. The thesis also explores the challenges and implications of restructuring within agriculture for growers, cooperatives and labour within the citrus industry. It is argued that whilst legislation related to labour and tenure within agriculture has changed since the mid-1990s, power relations in the citrus industry have remained firmly entrenched. Consequently, the flexible labour strategies that the citrus farmers adopted have had serious consequences for women worker
- Full Text:
- Date Issued: 2010
Collaborative monitoring in ecosystem management in South Africa's communal lands
- Authors: Bolus, Cosman
- Date: 2010
- Subjects: Conservation of natural resources -- South Africa , Natural resources -- South Africa -- Management , Community development -- South Africa -- Citizen participation , Conservation of natural resources -- Social aspects -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4743 , http://hdl.handle.net/10962/d1006948 , Conservation of natural resources -- South Africa , Natural resources -- South Africa -- Management , Community development -- South Africa -- Citizen participation , Conservation of natural resources -- Social aspects -- South Africa
- Description: Internationally there is an increasing focus on involving local communities in natural resource management and monitoring. Monitoring methods which are professionally driven appear to be inadequate to deal with the monitoring of natural resource use and biodiversity conservation, globally. This is especially evident in areas such as South African rural communal land. Two community based natural resource management (CBNRM) programmes in areas which are communally governed in the Eastern Cape, South Africa, namely Nqabara and Machubeni, were used as part of this research study. This thesis identified and tested potentially simple and cost effective monitoring methods related to the utilization of the local rangelands and indigenous forests. The criteria that were tested include 1) appropriateness and effectiveness in measuring change, and 2) contribution to building adaptive capacity among local land managers through learning. The criteria were assessed using a scoring system for each monitoring method in order to evaluate their strengths and weaknesses . This was done by using both quantitative and qualitative data. Contribution to building adaptive capacity was assessed by evaluating technical capacity gained, local ecological knowledge contributed and learning by participants. This was done using qualitative data. The results show that the monitoring methods had different strengths and weaknesses in relation to the criteria, making them more appropriate for different priorities such as effectively measuring change or building adaptive capacity. It is argued that an adaptive approach is a useful component in the participatory monitoring process. An adaptive framework was developed from lessons learnt in this study for collaborative monitoring. Challenges such as low literacy levels and adequate training still need to be addressed to strengthen efforts towards participatory monitoring. Factors such as incentives, conflict and local values may negatively affect the legitimacy and sustainability of participatory monitoring and therefore also need to be addressed.
- Full Text:
- Date Issued: 2010
- Authors: Bolus, Cosman
- Date: 2010
- Subjects: Conservation of natural resources -- South Africa , Natural resources -- South Africa -- Management , Community development -- South Africa -- Citizen participation , Conservation of natural resources -- Social aspects -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4743 , http://hdl.handle.net/10962/d1006948 , Conservation of natural resources -- South Africa , Natural resources -- South Africa -- Management , Community development -- South Africa -- Citizen participation , Conservation of natural resources -- Social aspects -- South Africa
- Description: Internationally there is an increasing focus on involving local communities in natural resource management and monitoring. Monitoring methods which are professionally driven appear to be inadequate to deal with the monitoring of natural resource use and biodiversity conservation, globally. This is especially evident in areas such as South African rural communal land. Two community based natural resource management (CBNRM) programmes in areas which are communally governed in the Eastern Cape, South Africa, namely Nqabara and Machubeni, were used as part of this research study. This thesis identified and tested potentially simple and cost effective monitoring methods related to the utilization of the local rangelands and indigenous forests. The criteria that were tested include 1) appropriateness and effectiveness in measuring change, and 2) contribution to building adaptive capacity among local land managers through learning. The criteria were assessed using a scoring system for each monitoring method in order to evaluate their strengths and weaknesses . This was done by using both quantitative and qualitative data. Contribution to building adaptive capacity was assessed by evaluating technical capacity gained, local ecological knowledge contributed and learning by participants. This was done using qualitative data. The results show that the monitoring methods had different strengths and weaknesses in relation to the criteria, making them more appropriate for different priorities such as effectively measuring change or building adaptive capacity. It is argued that an adaptive approach is a useful component in the participatory monitoring process. An adaptive framework was developed from lessons learnt in this study for collaborative monitoring. Challenges such as low literacy levels and adequate training still need to be addressed to strengthen efforts towards participatory monitoring. Factors such as incentives, conflict and local values may negatively affect the legitimacy and sustainability of participatory monitoring and therefore also need to be addressed.
- Full Text:
- Date Issued: 2010
Company-community participation as a conflict management strategy: a case study of AngloGold Ashanti in Mongbwalu, Democratic Republic of the Congo
- Authors: Barnett, Sarah
- Date: 2010
- Subjects: Conflict management -- Congo (Democratic Republic) , Mining corporations , Social participation
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:8200 , http://hdl.handle.net/10948/1265 , Conflict management -- Congo (Democratic Republic) , Mining corporations , Social participation
- Description: Mining companies operating in developing countries like the Democratic Republic of Congo (DRC) have come under increasing public criticism for not only failing to bring benefits to the country in which they operate but for often making the situation even worse through adverse environmental and social impacts. The particular focus of this treatise is the social division that a new mining project can generate between the operating company and the community living on or near to the mine site. In one area in north-eastern DRC, a large multinational mining company, AngloGold Ashanti, plans to develop a gold mine. While there have been no manifest conflicts between the company and the host community, there is evident latent conflict in the form of uncertainty and mistrust between parties. Although the company is engaged in two different models of companycommunity participation, this has either resulted in or failed to prevent tensions between the company and the local community. This research offers an exploration and discussion of the existing models of company-community participation as a conflict management strategy. With reference to relevant research and literature, as well as other available models for company-community participation, this treatise will provide a series of recommendations as to how the existing models could be made more effective in managing conflict.
- Full Text:
- Date Issued: 2010
- Authors: Barnett, Sarah
- Date: 2010
- Subjects: Conflict management -- Congo (Democratic Republic) , Mining corporations , Social participation
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:8200 , http://hdl.handle.net/10948/1265 , Conflict management -- Congo (Democratic Republic) , Mining corporations , Social participation
- Description: Mining companies operating in developing countries like the Democratic Republic of Congo (DRC) have come under increasing public criticism for not only failing to bring benefits to the country in which they operate but for often making the situation even worse through adverse environmental and social impacts. The particular focus of this treatise is the social division that a new mining project can generate between the operating company and the community living on or near to the mine site. In one area in north-eastern DRC, a large multinational mining company, AngloGold Ashanti, plans to develop a gold mine. While there have been no manifest conflicts between the company and the host community, there is evident latent conflict in the form of uncertainty and mistrust between parties. Although the company is engaged in two different models of companycommunity participation, this has either resulted in or failed to prevent tensions between the company and the local community. This research offers an exploration and discussion of the existing models of company-community participation as a conflict management strategy. With reference to relevant research and literature, as well as other available models for company-community participation, this treatise will provide a series of recommendations as to how the existing models could be made more effective in managing conflict.
- Full Text:
- Date Issued: 2010
Comparison of A₄ neutrino mass models
- Barry, James Munnik Hamilton
- Authors: Barry, James Munnik Hamilton
- Date: 2010
- Subjects: Neutrinos -- Mass , Standard model (Nuclear physics) , Particles (Nuclear physics)
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5554 , http://hdl.handle.net/10962/d1015271
- Description: The present neutrino oscillation data are compatible with tri-bimaximal mixing, to leading order. The addition of an A₄ family symmetry and extended Higgs sector to the Standard Model can generate this mixing pattern, assuming the correct vacuum expectation value alignment of Higgs scalars. The effect of deviating this alignment is studied, for different types of A₄ models, with a phenomenological emphasis: the effect of perturbations on the model predictions for the neutrino oscillation and neutrino mass observables. The standard theoretical description of neutrino oscillations is presented, along with a summary of the past, present and future experimental efforts aimed at measuring the neutrino mixing parameters. Additionally, the current constraints on the sum of absolute neutrino masses and the amplitude for neutrinoless double beta decay, which is yet to be observed, are discussed. These constraints provide a model-independent test of family symmetery models. The Standard Model is reviewed, and extensions to the Standard Model such as the seesaw mechanism(s) are discussed: these are designed to endow neutrinos with mass, and can be incorporated into A₄ symmetry models. Models with different A₄ particle assignments are analysed for deviations from tribimaximal mixing. There are nine models presented in Chapter 5, with lepton doublets transforming as 3 (underlined) and right-handed charged leptons transforming as 1, 1', 1" (all underlined) ; five of these include right-handed neutrinos transforming as 3 (underlined) and make use of the seesaw mechanism. Chapter 6 contains the analysis of six models that assign all leptons to the 3 (underlined) representation, with four of these utilising the seesaw mechanism. The models are tested for any degree of fine tuning of the parameters that define the mass matrices. The effect of perturbations on the mixing angle observables, in particular sin² ∅₁₃ and sin² ∅₂₃, is studied, as well as the effect on the Jarlskog invariant, Jcp. Investigations of the (Mee)- ∑Mv parameter space allow for comparison with current data, and can lead to the possible exclusion of a particular model by constraints from future data.
- Full Text:
- Date Issued: 2010
- Authors: Barry, James Munnik Hamilton
- Date: 2010
- Subjects: Neutrinos -- Mass , Standard model (Nuclear physics) , Particles (Nuclear physics)
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5554 , http://hdl.handle.net/10962/d1015271
- Description: The present neutrino oscillation data are compatible with tri-bimaximal mixing, to leading order. The addition of an A₄ family symmetry and extended Higgs sector to the Standard Model can generate this mixing pattern, assuming the correct vacuum expectation value alignment of Higgs scalars. The effect of deviating this alignment is studied, for different types of A₄ models, with a phenomenological emphasis: the effect of perturbations on the model predictions for the neutrino oscillation and neutrino mass observables. The standard theoretical description of neutrino oscillations is presented, along with a summary of the past, present and future experimental efforts aimed at measuring the neutrino mixing parameters. Additionally, the current constraints on the sum of absolute neutrino masses and the amplitude for neutrinoless double beta decay, which is yet to be observed, are discussed. These constraints provide a model-independent test of family symmetery models. The Standard Model is reviewed, and extensions to the Standard Model such as the seesaw mechanism(s) are discussed: these are designed to endow neutrinos with mass, and can be incorporated into A₄ symmetry models. Models with different A₄ particle assignments are analysed for deviations from tribimaximal mixing. There are nine models presented in Chapter 5, with lepton doublets transforming as 3 (underlined) and right-handed charged leptons transforming as 1, 1', 1" (all underlined) ; five of these include right-handed neutrinos transforming as 3 (underlined) and make use of the seesaw mechanism. Chapter 6 contains the analysis of six models that assign all leptons to the 3 (underlined) representation, with four of these utilising the seesaw mechanism. The models are tested for any degree of fine tuning of the parameters that define the mass matrices. The effect of perturbations on the mixing angle observables, in particular sin² ∅₁₃ and sin² ∅₂₃, is studied, as well as the effect on the Jarlskog invariant, Jcp. Investigations of the (Mee)- ∑Mv parameter space allow for comparison with current data, and can lead to the possible exclusion of a particular model by constraints from future data.
- Full Text:
- Date Issued: 2010
Comparison of the neuroprotective potential of theanine and minocycline
- Authors: Mpofu, Tariro Ann-Maureen
- Date: 2010 , 2010-09-20
- Subjects: Nervous system -- Degeneration -- Treatment , Tetracyclines , Antibiotics -- Side effects , Theanine -- Evaluation , Drugs -- Administration , Cerebrovascular disease -- Prevention
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3775 , http://hdl.handle.net/10962/d1003253 , Nervous system -- Degeneration -- Treatment , Tetracyclines , Antibiotics -- Side effects , Theanine -- Evaluation , Drugs -- Administration , Cerebrovascular disease -- Prevention
- Description: Stroke is one of the most common causes of disability and death worldwide. The most commonly experienced stroke in the clinical setting is focal ischaemia in which the middle cerebral artery (MCA) is occluded and leads to a complex series of various pathophysiological pathways that ultimately lead to neuronal cell death. Several studies have been conducted on various therapeutic agents in the search for a neuroprotective drug and various animal models have been used to carry out this research. While theanine, a component of green tea and minocycline, a tetracycline antibiotic, have been shown to possess some neuroprotective properties, the mechanisms by which these two agents carry out these effects still remains unclear. The objectives of this study were to investigate the mechanisms by which these drugs carry out these neuroprotective effects and their neuroprotective ability in a MCA occlusion model of focal ischaemia. Ischaemia leads to oxidative stress due to the imbalance of free radicals and the endogenous antioxidant defence system. An antioxidant assay using the stable 2, 2-diphenyl-1-picrylhydrazyl (DPPH●) radical was used to assess the antiradical properties of each drug. It was found that minocycline showed superior antioxidant activity in vitro when compared to theanine. Further studies on the drugs‟ ability to attenuate the Fenton reaction (in which iron catalyses the formation of reactive species) were elucidated using electrochemical analysis, UV/VIS studies, ferrozine and ferritin assays. It was found that minocycline, in contrast to theanine, was able to bind to iron ions and thus potentially prevent the participation of iron in metal catalysed radical reaction. The antioxidant activity of both drugs was further investigated by assessing their effect on cyanide-induced superoxide generation and quinolinic acid (QA)-induced lipid peroxidation (LP). Experimental evidence shows that both drugs had no significant effect on the generation of superoxide in vitro and that there was a significant decrease in LP for minocycline in vitro and theanine in vivo. The metal binding and antioxidant properties were postulated to be a possible mechanism through which these agents reduced lipid peroxidation. A study was conducted to determine the effects of the drugs on the biosynthesis of the neurotoxin, QA and it was found that minocycline increases the levels of holoenzyme activity of tryptophan-2, 3-dioxygenase (TDO) in vitro and that theanine reduces the levels of the same enzyme in vivo after treatment for 10 days. TDO is the enzyme that converts tryptophan to other products that enable enzymatic activity to change it to QA. Minocycline was thought to bring about this effect as it has been shown from preceding experimental studies that it is an effective reducing agent. Theanine on the other hand is hypothesised to bring about a reduction in holoenzyme activity by changing the binding of tryptophan to the enzyme or affecting the radicals that participate in the enzymatic degradation of tryptophan. A focal ischaemic model of stroke was induced by occluding the MCA. Histological examination of the hippocampus post -ischaemia shows a reduction in the size of the infarct after pre-treatment with minocycline only. A further study into the effects of the drugs on the generation of superoxide and on the levels of the endogenous glutathione after a stroke was carried out. Pre-treatment of the animals with either theanine or minocycline showed no significant effects on the generation of the radical species or of the endogenous antioxidant which ruled out these as a mechanism of neuroprotection of both drugs, post-ischaemia.The findings of this study provide novel information on the possible mechanisms by which both theanine and minocycline act to bring about neuroprotection. In particular in this study, pre-treatment with minocycline has shown promise in the focal ischaemic model of stroke.
- Full Text:
- Date Issued: 2010
- Authors: Mpofu, Tariro Ann-Maureen
- Date: 2010 , 2010-09-20
- Subjects: Nervous system -- Degeneration -- Treatment , Tetracyclines , Antibiotics -- Side effects , Theanine -- Evaluation , Drugs -- Administration , Cerebrovascular disease -- Prevention
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3775 , http://hdl.handle.net/10962/d1003253 , Nervous system -- Degeneration -- Treatment , Tetracyclines , Antibiotics -- Side effects , Theanine -- Evaluation , Drugs -- Administration , Cerebrovascular disease -- Prevention
- Description: Stroke is one of the most common causes of disability and death worldwide. The most commonly experienced stroke in the clinical setting is focal ischaemia in which the middle cerebral artery (MCA) is occluded and leads to a complex series of various pathophysiological pathways that ultimately lead to neuronal cell death. Several studies have been conducted on various therapeutic agents in the search for a neuroprotective drug and various animal models have been used to carry out this research. While theanine, a component of green tea and minocycline, a tetracycline antibiotic, have been shown to possess some neuroprotective properties, the mechanisms by which these two agents carry out these effects still remains unclear. The objectives of this study were to investigate the mechanisms by which these drugs carry out these neuroprotective effects and their neuroprotective ability in a MCA occlusion model of focal ischaemia. Ischaemia leads to oxidative stress due to the imbalance of free radicals and the endogenous antioxidant defence system. An antioxidant assay using the stable 2, 2-diphenyl-1-picrylhydrazyl (DPPH●) radical was used to assess the antiradical properties of each drug. It was found that minocycline showed superior antioxidant activity in vitro when compared to theanine. Further studies on the drugs‟ ability to attenuate the Fenton reaction (in which iron catalyses the formation of reactive species) were elucidated using electrochemical analysis, UV/VIS studies, ferrozine and ferritin assays. It was found that minocycline, in contrast to theanine, was able to bind to iron ions and thus potentially prevent the participation of iron in metal catalysed radical reaction. The antioxidant activity of both drugs was further investigated by assessing their effect on cyanide-induced superoxide generation and quinolinic acid (QA)-induced lipid peroxidation (LP). Experimental evidence shows that both drugs had no significant effect on the generation of superoxide in vitro and that there was a significant decrease in LP for minocycline in vitro and theanine in vivo. The metal binding and antioxidant properties were postulated to be a possible mechanism through which these agents reduced lipid peroxidation. A study was conducted to determine the effects of the drugs on the biosynthesis of the neurotoxin, QA and it was found that minocycline increases the levels of holoenzyme activity of tryptophan-2, 3-dioxygenase (TDO) in vitro and that theanine reduces the levels of the same enzyme in vivo after treatment for 10 days. TDO is the enzyme that converts tryptophan to other products that enable enzymatic activity to change it to QA. Minocycline was thought to bring about this effect as it has been shown from preceding experimental studies that it is an effective reducing agent. Theanine on the other hand is hypothesised to bring about a reduction in holoenzyme activity by changing the binding of tryptophan to the enzyme or affecting the radicals that participate in the enzymatic degradation of tryptophan. A focal ischaemic model of stroke was induced by occluding the MCA. Histological examination of the hippocampus post -ischaemia shows a reduction in the size of the infarct after pre-treatment with minocycline only. A further study into the effects of the drugs on the generation of superoxide and on the levels of the endogenous glutathione after a stroke was carried out. Pre-treatment of the animals with either theanine or minocycline showed no significant effects on the generation of the radical species or of the endogenous antioxidant which ruled out these as a mechanism of neuroprotection of both drugs, post-ischaemia.The findings of this study provide novel information on the possible mechanisms by which both theanine and minocycline act to bring about neuroprotection. In particular in this study, pre-treatment with minocycline has shown promise in the focal ischaemic model of stroke.
- Full Text:
- Date Issued: 2010