Studies on mixed-species colonies of honeybees, Apis cerana and Apis mellifera
- Authors: Yang, Ming-Xian
- Date: 2010
- Subjects: Bees Apis cerana Honeybee Honeybee -- Behavior Bee culture Honeybee -- Physiology Insect societies Animal communication Bees -- Nests
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5779 , http://hdl.handle.net/10962/d1005467
- Description: The honeybees Apis cerana and Apis mellifera are derived from the same ancestral base about two million years ago. With speciation and evolution, they have acquired many advanced living skills in common, but have also evolved very different living strategies due to different distributions. This thesis is an intensive study of the biology of the mixed-species colonies of these species, the aims of which were to investigate their behavioural relationships and uncover the evolutionary conserved features of their behaviours subsequent to speciation. The results show that the two species can form a stable society to perform normal tasks. First, workers of both species in the mixed-colonies could form the typical retinue behaviour to hetero-species queens, thus indicating that queen pheromones could be spread to and by both species. Secondly, both species did not show significantly different ovarian activation under hetero-species queens, suggesting that the queen pheromones more likely play a role of "honest signal" rather than a "repression" substance in the honeybee colonies. Thirdly, both species could mutually decode each other‘s waggle dances, with unexpectedly low misunderstanding; revealing that the dance language in a dark environment is quite adaptive for cavity-nesting honeybees. Fourthly, workers of both species could cooperate with each other in comb construction, although the combs they built contain many irregular cells. Interestingly, A. cerana workers could be stimulated by A. mellifera workers to perform this task, thus confirming self-organization theory in the colony. Fifthly, A. mellifera workers behaved more "defectively" in thermoregulation, but perhaps because A. cerana workers are more sensitive to changes in hive temperature. Given these differences in strategy, A. mellifera workers‘ performance might in fact reduce conflicts. Lastly, when faced with threats of predatory wasps, both species engaged in aggressive defence. Although they did not learn from each other‘s responses, species-specific strategies were adopted by each of them so that the defence of the mixed-colonies is very effective. I conclude that the two species can adapt to each other‘s efforts and task allocation is reasonably organized allowing mixed-species colonies to reach stability. These results suggest that all of the social behaviours discussed here were highly conserved following speciation. This thesis could provide some clues for the study of honeybee evolution from open-nesting to the transition of cavity-nesting.
- Full Text:
- Date Issued: 2010
- Authors: Yang, Ming-Xian
- Date: 2010
- Subjects: Bees Apis cerana Honeybee Honeybee -- Behavior Bee culture Honeybee -- Physiology Insect societies Animal communication Bees -- Nests
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5779 , http://hdl.handle.net/10962/d1005467
- Description: The honeybees Apis cerana and Apis mellifera are derived from the same ancestral base about two million years ago. With speciation and evolution, they have acquired many advanced living skills in common, but have also evolved very different living strategies due to different distributions. This thesis is an intensive study of the biology of the mixed-species colonies of these species, the aims of which were to investigate their behavioural relationships and uncover the evolutionary conserved features of their behaviours subsequent to speciation. The results show that the two species can form a stable society to perform normal tasks. First, workers of both species in the mixed-colonies could form the typical retinue behaviour to hetero-species queens, thus indicating that queen pheromones could be spread to and by both species. Secondly, both species did not show significantly different ovarian activation under hetero-species queens, suggesting that the queen pheromones more likely play a role of "honest signal" rather than a "repression" substance in the honeybee colonies. Thirdly, both species could mutually decode each other‘s waggle dances, with unexpectedly low misunderstanding; revealing that the dance language in a dark environment is quite adaptive for cavity-nesting honeybees. Fourthly, workers of both species could cooperate with each other in comb construction, although the combs they built contain many irregular cells. Interestingly, A. cerana workers could be stimulated by A. mellifera workers to perform this task, thus confirming self-organization theory in the colony. Fifthly, A. mellifera workers behaved more "defectively" in thermoregulation, but perhaps because A. cerana workers are more sensitive to changes in hive temperature. Given these differences in strategy, A. mellifera workers‘ performance might in fact reduce conflicts. Lastly, when faced with threats of predatory wasps, both species engaged in aggressive defence. Although they did not learn from each other‘s responses, species-specific strategies were adopted by each of them so that the defence of the mixed-colonies is very effective. I conclude that the two species can adapt to each other‘s efforts and task allocation is reasonably organized allowing mixed-species colonies to reach stability. These results suggest that all of the social behaviours discussed here were highly conserved following speciation. This thesis could provide some clues for the study of honeybee evolution from open-nesting to the transition of cavity-nesting.
- Full Text:
- Date Issued: 2010
Studies towards the development of novel HIV-1 integrase inhibitors
- Authors: Lee, Yi-Chen
- Date: 2010
- Subjects: HIV infections -- Treatment , HIV (Viruses) , AIDS (Disease) -- Treatment , Nuclear magnetic resonance , Heterocyclic compounds -- Derivatives , Enzyme inhibitors , Chemical inhibitors , Quinoline
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4357 , http://hdl.handle.net/10962/d1005022 , HIV infections -- Treatment , HIV (Viruses) , AIDS (Disease) -- Treatment , Nuclear magnetic resonance , Heterocyclic compounds -- Derivatives , Enzyme inhibitors , Chemical inhibitors , Quinoline
- Description: The project has focused on the preparation of several series of compounds designed as potential HIV-1 integrase inhibitors. Various 2-nitrobenzaldehydes have been reacted with two activated alkenes, methyl vinyl ketone (MVK) and methyl acrylate, under Baylis-Hillman conditions to afford α-methylene-β-hydroxylalkyl derivatives in moderate to excellent yields. The reactions were conducted using the tertiary amine catalysts, 1,4-diazabicyclo[2.2.2]octane(DABCO) or 3-hydroxyquinuclidine (3-HQ) with chloroform as solvent, and yields were optimised by varying the catalyst, reagent concentrations and the reaction time. Reductive cyclization of the Baylis-Hillman adducts via catalytic hydrogenation, using 10% palladiumon-carbon catalyst in ethanol, afforded quinoline and quinoline N-oxide derivatives. In some cases “acyclic” reduction products were also isolated. Reaction of the Baylis-Hillman MVK adducts with HCl, has resulted in effective nucleophilic (SN’) displacement of the hydroxyl group to afford allylic chloride derivatives. Direct substitution of these chloro derivatives by secondary or primary amines, followed by catalytic hydrogenation gave quinoline derivatives containing a 3-aminomethyl substituent. The Baylis-Hillman ester adducts obtained from reaction with methyl acrylate were treated directly with various amines to give diastereomeric conjugate addition products. Reactions with piperazine gave N,N’-disubstituted piperazine products. The piperidine derivatives have been dehydrated to give cinnamate esters in moderate yields. The products, which have all been satisfactorily characterised by elemental (HRMS) and spectroscopic (1- and 2-D NMR) analysis, constitute a “library” of compounds for in silico and in vitro studies as potential HIV integrase inhibitors.
- Full Text:
- Date Issued: 2010
- Authors: Lee, Yi-Chen
- Date: 2010
- Subjects: HIV infections -- Treatment , HIV (Viruses) , AIDS (Disease) -- Treatment , Nuclear magnetic resonance , Heterocyclic compounds -- Derivatives , Enzyme inhibitors , Chemical inhibitors , Quinoline
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4357 , http://hdl.handle.net/10962/d1005022 , HIV infections -- Treatment , HIV (Viruses) , AIDS (Disease) -- Treatment , Nuclear magnetic resonance , Heterocyclic compounds -- Derivatives , Enzyme inhibitors , Chemical inhibitors , Quinoline
- Description: The project has focused on the preparation of several series of compounds designed as potential HIV-1 integrase inhibitors. Various 2-nitrobenzaldehydes have been reacted with two activated alkenes, methyl vinyl ketone (MVK) and methyl acrylate, under Baylis-Hillman conditions to afford α-methylene-β-hydroxylalkyl derivatives in moderate to excellent yields. The reactions were conducted using the tertiary amine catalysts, 1,4-diazabicyclo[2.2.2]octane(DABCO) or 3-hydroxyquinuclidine (3-HQ) with chloroform as solvent, and yields were optimised by varying the catalyst, reagent concentrations and the reaction time. Reductive cyclization of the Baylis-Hillman adducts via catalytic hydrogenation, using 10% palladiumon-carbon catalyst in ethanol, afforded quinoline and quinoline N-oxide derivatives. In some cases “acyclic” reduction products were also isolated. Reaction of the Baylis-Hillman MVK adducts with HCl, has resulted in effective nucleophilic (SN’) displacement of the hydroxyl group to afford allylic chloride derivatives. Direct substitution of these chloro derivatives by secondary or primary amines, followed by catalytic hydrogenation gave quinoline derivatives containing a 3-aminomethyl substituent. The Baylis-Hillman ester adducts obtained from reaction with methyl acrylate were treated directly with various amines to give diastereomeric conjugate addition products. Reactions with piperazine gave N,N’-disubstituted piperazine products. The piperidine derivatives have been dehydrated to give cinnamate esters in moderate yields. The products, which have all been satisfactorily characterised by elemental (HRMS) and spectroscopic (1- and 2-D NMR) analysis, constitute a “library” of compounds for in silico and in vitro studies as potential HIV integrase inhibitors.
- Full Text:
- Date Issued: 2010
Study South Africa
- International Education Association of South Africa (IEASA), Jooste, Nico
- Authors: International Education Association of South Africa (IEASA) , Jooste, Nico
- Date: 2010
- Subjects: Education, Higher -- South Africa , Universities and colleges -- South Africa , Technical Institutes -- South Africa , Vocational guidance -- South Africa
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10962/64963 , vital:28640 , ISBN 9780620482172
- Description: [Extract from message from Minister of Higher Education and Training, Hon. Dr BE Nzimande]: The 10th Edition focuses on the highly relevant issue of ‘Higher Education Internationalisation in the Development of Africa’. The internationalisation of higher education is of great importance for the continent, if Africa wants to be able to compete and participate in a global context. Currently, there are only three African institutions in the Top 500 of the Shanghai Academic Ranking of World Universities and all of these are in South Africa. Similarly, one South African institution appears in the Top 200 of the Times Higher Education World Ranking and no other African universities are represented. Despite being cautious about the methodology used to derive rankings, our aim in higher education should be to actively compete internationally and, more importantly, to serve the developmental challenges of Africa. It is imperative that Africa engages internationally and participates in the development of humanity’s knowledge. Research outputs and publications are particularly low on the continent, and African universities need to develop their research capabilities and direct resources to this important function. It is particularly important that research, which affects Africa and its development, is conducted on a large scale on the continent, supported by collaborative work and partnerships, rather than being carried out predominantly in other countries. The time has come for the tide to change and for our researchers and academics to focus on research opportunities presented on the continent. This is an important step for Africa to take if it is to deal effectively with the problems it faces and take its place in the international arena. One way to increase and develop knowledge outputs is through collaboration. An important opportunity for South African universities is the Erasmus Mundus Programme funded through the European Union (EU). This programme encourages collaboration between South African and European universities and provides resources for the exchange of staff and students within specific research programmes. It is also important for Africa to develop the research collaboration within the continent and with other developing and developed countries. In this regard, the Intra-ACP (Africa-Caribbean-Pacific) Scheme is of great importance. This initiative by the African Union (AU), working in collaboration with the EU, provides the opportunity for academic staff and student exchanges between universities in these regions. Intra-African exchanges are of particular importance in developing the continent’s capacity. Through such programmes African universities can work together to develop research and participate in the knowledge economy. We should also not ignore the challenges faced in improving the quality of teaching and learning in African universities, including many in South Africa. If sufficient attention and resources are not directed to improving these most basic activities of higher education, we will not only fail to meet the continent’s human resource development needs, but we will fail to establish the basis for future research advancement. Student mobility is very much a part of our fabric and provides the necessary intellectual stimulation, which is an essential part of student life. The number of African students from outside South Africa studying at South African institutions is growing annually, as is the number of non-African students. The networks established through such internationalisation are invaluable. There are also large numbers of our own students who, through universities’ reciprocal agreements, are studying abroad. The information provided in this publication provides a valuable opportunity to showcase our higher education sector and goes a long way to providing the necessary facts to encourage such student mobility. , 10th Edition
- Full Text:
- Date Issued: 2010
- Authors: International Education Association of South Africa (IEASA) , Jooste, Nico
- Date: 2010
- Subjects: Education, Higher -- South Africa , Universities and colleges -- South Africa , Technical Institutes -- South Africa , Vocational guidance -- South Africa
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10962/64963 , vital:28640 , ISBN 9780620482172
- Description: [Extract from message from Minister of Higher Education and Training, Hon. Dr BE Nzimande]: The 10th Edition focuses on the highly relevant issue of ‘Higher Education Internationalisation in the Development of Africa’. The internationalisation of higher education is of great importance for the continent, if Africa wants to be able to compete and participate in a global context. Currently, there are only three African institutions in the Top 500 of the Shanghai Academic Ranking of World Universities and all of these are in South Africa. Similarly, one South African institution appears in the Top 200 of the Times Higher Education World Ranking and no other African universities are represented. Despite being cautious about the methodology used to derive rankings, our aim in higher education should be to actively compete internationally and, more importantly, to serve the developmental challenges of Africa. It is imperative that Africa engages internationally and participates in the development of humanity’s knowledge. Research outputs and publications are particularly low on the continent, and African universities need to develop their research capabilities and direct resources to this important function. It is particularly important that research, which affects Africa and its development, is conducted on a large scale on the continent, supported by collaborative work and partnerships, rather than being carried out predominantly in other countries. The time has come for the tide to change and for our researchers and academics to focus on research opportunities presented on the continent. This is an important step for Africa to take if it is to deal effectively with the problems it faces and take its place in the international arena. One way to increase and develop knowledge outputs is through collaboration. An important opportunity for South African universities is the Erasmus Mundus Programme funded through the European Union (EU). This programme encourages collaboration between South African and European universities and provides resources for the exchange of staff and students within specific research programmes. It is also important for Africa to develop the research collaboration within the continent and with other developing and developed countries. In this regard, the Intra-ACP (Africa-Caribbean-Pacific) Scheme is of great importance. This initiative by the African Union (AU), working in collaboration with the EU, provides the opportunity for academic staff and student exchanges between universities in these regions. Intra-African exchanges are of particular importance in developing the continent’s capacity. Through such programmes African universities can work together to develop research and participate in the knowledge economy. We should also not ignore the challenges faced in improving the quality of teaching and learning in African universities, including many in South Africa. If sufficient attention and resources are not directed to improving these most basic activities of higher education, we will not only fail to meet the continent’s human resource development needs, but we will fail to establish the basis for future research advancement. Student mobility is very much a part of our fabric and provides the necessary intellectual stimulation, which is an essential part of student life. The number of African students from outside South Africa studying at South African institutions is growing annually, as is the number of non-African students. The networks established through such internationalisation are invaluable. There are also large numbers of our own students who, through universities’ reciprocal agreements, are studying abroad. The information provided in this publication provides a valuable opportunity to showcase our higher education sector and goes a long way to providing the necessary facts to encourage such student mobility. , 10th Edition
- Full Text:
- Date Issued: 2010
Suitability of the leaf-mining fly, Pseudonapomyza sp. (Diptera: Agromyzidae), for biological control of Tecoma stans L. (Bignoniaceae) in South Africa
- Authors: Madire, Lulama Gracious
- Date: 2010
- Subjects: Diptera -- Biological control , Bignoniaceae -- Biological control , Plants, Ornamental -- Diseases and pests , Agromyzidae
- Language: English
- Type: Thesis , Masters , MSc (Zoology)
- Identifier: vital:11790 , http://hdl.handle.net/10353/255 , Diptera -- Biological control , Bignoniaceae -- Biological control , Plants, Ornamental -- Diseases and pests , Agromyzidae
- Description: Tecoma stans (L.) Juss. Ex Kunth (Bignoniaceae) also known as yellow bells, has a native distribution from Northern Argentina, central America, Mexico and the Southern USA. In many warm climatic regions of the world, T. stans is commonly planted as an ornamental plant because of its yellow flowers, hence the name yellow bells, and pinnate foliage. As a result, this evergreen shrub has wide distribution in the tropical and subtropical parts of the western hemisphere. As is the case in many other parts of the world, T. stans was introduced into South Africa as an ornamental plant, but escaped cultivation and now invades roadsides, urban open spaces, watercourses, rocky sites in subtropical and tropical areas of five South African provinces; Gauteng, Mpumalanga, Limpopo, KwaZulu-Natal, Eastern Cape and neighboring countries. Tecoma stans has the potential of extending its range because its seeds are easily dispersed by wind. The purpose of this work was to carry out pre-release efficacy studies to determine the host specificity and suitability of Pseudonapomyza sp. (Diptera: Agromyzidae), a leaf-mining fly, as a biological control agent of T. stans. Available information suggests that the fly was brought to South Africa (SA) from Argentina in 2005. In that year a worker collected adult root feeding fleabeetles from T. stans and their eggs by collecting soil around the plants in the Argentinian Province of Jujuy, at San Pedro (24°12’592”S, 64°51’328”W). The soil was brought to the SA quarantine laboratory of the Agricultural Research Council, Plant Protection Research Institute (Weeds Division), Pretoria, and placed in a cage containing T. stans plants for flea-beetle larvae to emerge from the eggs. The Pseudonapomyza sp. flies which emerged from that soil were reared to produce a colony of flies used in the study reported here. The feeding behavior of Pseudonapomyza sp. adults is initiated by females which use their ovipositor to puncture holes in the leaf mesophyll and then they feed on the sap oozing from the holes. Since males have no means of puncturing the leaves, they feed from holes made by females. Eggs are laid singly into the tubular leaf punctures. Soon after hatching, the larva feeds on the leaf mesophyll tissue. As the larva feeds within the leaf it creates mines which eventually coalesce to form large blotches. The damaged leaf area reduces the photosynthetic potential of the plant especially when damaged leaves dry and fall off the plants. The potential of Pseudonapomyza sp. as a biocontrol agent is enhanced by the fact that it has a high level of fecundity and a short life cycle. As a result, its populations can build up rapidly to exert a significant impact on T. stans. Host-specificity tests undertaken on 35 plant species in 12 plant families showed that out of the 35 plant species tested, the fly was able to develop on T. stans only. Although Pseudonapomyza sp. adults fed on T. capensis, a South African indigenous ornamental shrub, no larval mines were observed on this plant. This suggests two possibilities; either females of Pseudonapomyza sp. do not oviposit on T. capensis or oviposition takes place but larvae cannot feed and develop on this plant. These studies indicate that this fly is sufficiently host-specific, and can be released against T. stans without posing any threat to either commercial or indigenous plant species grown in South Africa. Experimental designs simulating high populations of Pseudonapomyza sp. showed that the impact of leaf mining fly on T. stans can cause approximately 56 percent aboveground biomass reduction. Other concurrent studies have also showed that low and high density fly infestations can cause 23 percent and 48 percent belowground biomass reductions, respectively. Based on the available information, it appears that Pseudonapomyza sp. may have the potential to reduce the invasive capacity of T. stans in the affected areas. In order to exert more herbivore pressure on T. stans, it is suggested that agents belonging to other feeding guilds, such as root-, stem- and seed-feeding insects, be considered for release to complement the leaf-feeding of Pseudonapomyza sp. An application to release this fly in SA has been submitted to one of the two regulatory authorities.
- Full Text:
- Date Issued: 2010
- Authors: Madire, Lulama Gracious
- Date: 2010
- Subjects: Diptera -- Biological control , Bignoniaceae -- Biological control , Plants, Ornamental -- Diseases and pests , Agromyzidae
- Language: English
- Type: Thesis , Masters , MSc (Zoology)
- Identifier: vital:11790 , http://hdl.handle.net/10353/255 , Diptera -- Biological control , Bignoniaceae -- Biological control , Plants, Ornamental -- Diseases and pests , Agromyzidae
- Description: Tecoma stans (L.) Juss. Ex Kunth (Bignoniaceae) also known as yellow bells, has a native distribution from Northern Argentina, central America, Mexico and the Southern USA. In many warm climatic regions of the world, T. stans is commonly planted as an ornamental plant because of its yellow flowers, hence the name yellow bells, and pinnate foliage. As a result, this evergreen shrub has wide distribution in the tropical and subtropical parts of the western hemisphere. As is the case in many other parts of the world, T. stans was introduced into South Africa as an ornamental plant, but escaped cultivation and now invades roadsides, urban open spaces, watercourses, rocky sites in subtropical and tropical areas of five South African provinces; Gauteng, Mpumalanga, Limpopo, KwaZulu-Natal, Eastern Cape and neighboring countries. Tecoma stans has the potential of extending its range because its seeds are easily dispersed by wind. The purpose of this work was to carry out pre-release efficacy studies to determine the host specificity and suitability of Pseudonapomyza sp. (Diptera: Agromyzidae), a leaf-mining fly, as a biological control agent of T. stans. Available information suggests that the fly was brought to South Africa (SA) from Argentina in 2005. In that year a worker collected adult root feeding fleabeetles from T. stans and their eggs by collecting soil around the plants in the Argentinian Province of Jujuy, at San Pedro (24°12’592”S, 64°51’328”W). The soil was brought to the SA quarantine laboratory of the Agricultural Research Council, Plant Protection Research Institute (Weeds Division), Pretoria, and placed in a cage containing T. stans plants for flea-beetle larvae to emerge from the eggs. The Pseudonapomyza sp. flies which emerged from that soil were reared to produce a colony of flies used in the study reported here. The feeding behavior of Pseudonapomyza sp. adults is initiated by females which use their ovipositor to puncture holes in the leaf mesophyll and then they feed on the sap oozing from the holes. Since males have no means of puncturing the leaves, they feed from holes made by females. Eggs are laid singly into the tubular leaf punctures. Soon after hatching, the larva feeds on the leaf mesophyll tissue. As the larva feeds within the leaf it creates mines which eventually coalesce to form large blotches. The damaged leaf area reduces the photosynthetic potential of the plant especially when damaged leaves dry and fall off the plants. The potential of Pseudonapomyza sp. as a biocontrol agent is enhanced by the fact that it has a high level of fecundity and a short life cycle. As a result, its populations can build up rapidly to exert a significant impact on T. stans. Host-specificity tests undertaken on 35 plant species in 12 plant families showed that out of the 35 plant species tested, the fly was able to develop on T. stans only. Although Pseudonapomyza sp. adults fed on T. capensis, a South African indigenous ornamental shrub, no larval mines were observed on this plant. This suggests two possibilities; either females of Pseudonapomyza sp. do not oviposit on T. capensis or oviposition takes place but larvae cannot feed and develop on this plant. These studies indicate that this fly is sufficiently host-specific, and can be released against T. stans without posing any threat to either commercial or indigenous plant species grown in South Africa. Experimental designs simulating high populations of Pseudonapomyza sp. showed that the impact of leaf mining fly on T. stans can cause approximately 56 percent aboveground biomass reduction. Other concurrent studies have also showed that low and high density fly infestations can cause 23 percent and 48 percent belowground biomass reductions, respectively. Based on the available information, it appears that Pseudonapomyza sp. may have the potential to reduce the invasive capacity of T. stans in the affected areas. In order to exert more herbivore pressure on T. stans, it is suggested that agents belonging to other feeding guilds, such as root-, stem- and seed-feeding insects, be considered for release to complement the leaf-feeding of Pseudonapomyza sp. An application to release this fly in SA has been submitted to one of the two regulatory authorities.
- Full Text:
- Date Issued: 2010
Surveillance of invasive vibro species in discharged aqueous efflents of wastewater treatment plants in the Eastern Cape province of South Africa
- Authors: Igbinosa, Etinosa Ogbomoede
- Date: 2010
- Subjects: Vibrio -- South Africa -- Eastern Cape , Water -- Fluoridation -- South Africa -- Eastern Cape , Water -- Pollution -- South Africa -- Eastern Cape , Effluent quality -- South Africa -- Eastern Cape , Water -- Purification -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , PhD (Microbiology)
- Identifier: vital:11267 , http://hdl.handle.net/10353/245 , Vibrio -- South Africa -- Eastern Cape , Water -- Fluoridation -- South Africa -- Eastern Cape , Water -- Pollution -- South Africa -- Eastern Cape , Effluent quality -- South Africa -- Eastern Cape , Water -- Purification -- South Africa -- Eastern Cape
- Description: Vibrio infections remain a serious threat to public health. In the last decade, Vibrio disease outbreaks have created a painful awareness of the personal, economic, societal, and public health costs associated with the impact of contaminated water in the aquatic milieu. This study was therefore designed to assess the prevalence of Vibrio pathogens in the final effluents of wastewater treatment plants (WWTPs) in the Eastern Cape Province, as well as their abilities to survive the treatment processes of the activated sludge system either as free cells or as plankton-associated entities in relation to the physicochemical qualities of the effluents. Three wastewater treatment facilities were selected to represent typical urban, sub-urban and rural communities, and samples were collected monthly from August 2007 to July 2008 from the final effluent, discharge point, 500 meter upstream and downstream of the discharge points and analysed for physicochemical parameters, Vibrio pathogens prevalence and their antibiogram characteristics using both culture based and molecular techniques. Physicochemical parameters measured include pH, temperature, electrical conductivity, salinity, turbidity, total dissolved solid (TDS), dissolved oxygen (DO), chemical oxygen demand (COD), nitrate, nitrite and orthophosphate levels. Unacceptably high levels of the assayed parameters were observed in many cases for COD (<10 - 1180 mg/l), nitrate (0.08 - 13.14 mg NO3- as N/l), nitrite (0.06 - 6.78 mg NO2- as N/l), orthophosphate (0.07-4.81 mg PO43- as P/l), DO (1.24 - 11.22 mg/l) and turbidity (2.04 -159.06 NTU). Temperature, COD and nitrite varied significantly with season (P < 0.05), while pH, EC, salinity, TDS, COD, and nitrate all varied significantly with sampling site (P < 0.01; P < 0.05). In the rural wastewater treatment facility, free-living Vibrio densities varied from 0 to 3.45 × 101 cfu ml-1, while the plankton-associated Vibrio densities vary with plankton sizes as follows: 180 μm (0 – 4.50 × 103 cfu ml-1); 60 μm (0 – 4.86 × 103 cfu ml-1); 20 μm (0 – 1.9 × 105 cfu ml-1). The seasonal variations in the Vibrio densities in the 180 and 60 μm plankton size samples were significant (P < 0.05), while the 20 μm plankton size and free-living vibrios densities were not. Molecular confirmation of the presumptive vibrios isolates revealed V. fluvialis (36.5 percent), as the predominant species, followed by V. vulnificus (34.6 percent), and V. parahaemolyticus (23.1 percent), and V. metschnikovii (5.8 percent) (detected using only API 20 NE), suggesting high incidence of pathogenic Vibrio species in the final effluent of the wastewater facility. Correlation analysis suggested that the concentration of Vibrio species correlated negatively with salinity and temperature (P < 0.001 and P < 0.002 respectively) as well as with pH and turbidity (P < 0.001), in the final effluent. Population density of total Vibrio ranged from 2.1 × 101 to 4.36 × 104 cfu ml-1 and from 2.80 ×101 to 1.80 × 105 cfu ml-1 for the sub-urban and urban communities treatment facilities respectively. Vibrio species associated with 180 μm, 60 μm, and 20 μm plankton sizes, were observed at densities of 0 - 1.36 × 103 cfu ml-1, 0 - 8.40 × 102 cfu ml-1 and 0 - 6.80 × 102 cfu ml-1 respectively at the sub-urban community‘s WWTP. In the urban community, counts of culturable vibrios ranged from 0 - 2.80 × 102 cfu ml-1 (180 μm); 0 - 6.60 × 102 cfu ml-1 (60 μm) and 0 -1.80 × 103 cfu ml-1 (20 μm). Abundance of free-living Vibrio species varied between 0 and the orders of 102 and 103 cfu ml-1 in the sub-urban and urban communities WWTPs respectively. Molecular confirmation of the presumptive vibrios isolates revealed the presence of V. fluvialis (41.38 percent), V. vulnificus (34.48 percent), and V. parahaemolyticus (24.14 percent) in the sub-urban community effluents. In the urban community V. fluvialis (40 percent), V. vulnificus (36 percent), and V. parahaemolyticus (24 percent) were detected. There was no significant correlation between Vibrio abundance and season, either as free-living or plankton-associated entities, while Vibrio species abundance correlated positively with temperature (r = 0.565; P < 0.01), salinity and dissolved oxygen (P < 0.05). Turbidity and pH showed significant seasonal variation (P < 0.05) in both locations. The Vibrio strains showed the typical multi-antibiotic-resistance of an SXT element. They were resistant to sulfamethoxazole (Sul), trimethoprim (Tmp), cotrimoxazole (Cot), chloramphenicol (Chl) and streptomycin (Str), as well as other antibiotics such as ampicillin (Amp), penicillin (Pen), erythromycin (Ery), tetracycline (Tet), nalidixic acid (Nal), and gentamicin (Gen). The antibiotic resistance genes detected includes dfr18 and dfrA1 for trimethoprim; tetA, strB, floR, sul2 blaP1, for tetracycline, streptomycin, chloramphenicol, sulfamethoxazole and β-lactams respectively. A number of these genes were only recently described from clinical isolates, demonstrating genetic exchange between clinical and environmental Vibrio species. This study revealed that there was an adverse impact on the physicochemical characteristics of the receiving watershed as a result of the discharge of inadequately treated effluents from the wastewater treatment facilities. The occurrence of Vibrio species as plankton-associated entities confirms the role of plankton as potential reservoir for this pathogen. Also the treated final effluents are reservoirs of various antibiotics resistance genes. This could pose significant health and environmental risk to the biotic component of the environment including communities that rely on the receiving water for domestic purposes and may also affect the health status of the aquatic milieu in the receiving water. There is need for consistent monitoring programme by appropriate regulatory agencies to ensure compliance of the wastewater treatment facilities to regulatory effluent quality standards.
- Full Text:
- Date Issued: 2010
- Authors: Igbinosa, Etinosa Ogbomoede
- Date: 2010
- Subjects: Vibrio -- South Africa -- Eastern Cape , Water -- Fluoridation -- South Africa -- Eastern Cape , Water -- Pollution -- South Africa -- Eastern Cape , Effluent quality -- South Africa -- Eastern Cape , Water -- Purification -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , PhD (Microbiology)
- Identifier: vital:11267 , http://hdl.handle.net/10353/245 , Vibrio -- South Africa -- Eastern Cape , Water -- Fluoridation -- South Africa -- Eastern Cape , Water -- Pollution -- South Africa -- Eastern Cape , Effluent quality -- South Africa -- Eastern Cape , Water -- Purification -- South Africa -- Eastern Cape
- Description: Vibrio infections remain a serious threat to public health. In the last decade, Vibrio disease outbreaks have created a painful awareness of the personal, economic, societal, and public health costs associated with the impact of contaminated water in the aquatic milieu. This study was therefore designed to assess the prevalence of Vibrio pathogens in the final effluents of wastewater treatment plants (WWTPs) in the Eastern Cape Province, as well as their abilities to survive the treatment processes of the activated sludge system either as free cells or as plankton-associated entities in relation to the physicochemical qualities of the effluents. Three wastewater treatment facilities were selected to represent typical urban, sub-urban and rural communities, and samples were collected monthly from August 2007 to July 2008 from the final effluent, discharge point, 500 meter upstream and downstream of the discharge points and analysed for physicochemical parameters, Vibrio pathogens prevalence and their antibiogram characteristics using both culture based and molecular techniques. Physicochemical parameters measured include pH, temperature, electrical conductivity, salinity, turbidity, total dissolved solid (TDS), dissolved oxygen (DO), chemical oxygen demand (COD), nitrate, nitrite and orthophosphate levels. Unacceptably high levels of the assayed parameters were observed in many cases for COD (<10 - 1180 mg/l), nitrate (0.08 - 13.14 mg NO3- as N/l), nitrite (0.06 - 6.78 mg NO2- as N/l), orthophosphate (0.07-4.81 mg PO43- as P/l), DO (1.24 - 11.22 mg/l) and turbidity (2.04 -159.06 NTU). Temperature, COD and nitrite varied significantly with season (P < 0.05), while pH, EC, salinity, TDS, COD, and nitrate all varied significantly with sampling site (P < 0.01; P < 0.05). In the rural wastewater treatment facility, free-living Vibrio densities varied from 0 to 3.45 × 101 cfu ml-1, while the plankton-associated Vibrio densities vary with plankton sizes as follows: 180 μm (0 – 4.50 × 103 cfu ml-1); 60 μm (0 – 4.86 × 103 cfu ml-1); 20 μm (0 – 1.9 × 105 cfu ml-1). The seasonal variations in the Vibrio densities in the 180 and 60 μm plankton size samples were significant (P < 0.05), while the 20 μm plankton size and free-living vibrios densities were not. Molecular confirmation of the presumptive vibrios isolates revealed V. fluvialis (36.5 percent), as the predominant species, followed by V. vulnificus (34.6 percent), and V. parahaemolyticus (23.1 percent), and V. metschnikovii (5.8 percent) (detected using only API 20 NE), suggesting high incidence of pathogenic Vibrio species in the final effluent of the wastewater facility. Correlation analysis suggested that the concentration of Vibrio species correlated negatively with salinity and temperature (P < 0.001 and P < 0.002 respectively) as well as with pH and turbidity (P < 0.001), in the final effluent. Population density of total Vibrio ranged from 2.1 × 101 to 4.36 × 104 cfu ml-1 and from 2.80 ×101 to 1.80 × 105 cfu ml-1 for the sub-urban and urban communities treatment facilities respectively. Vibrio species associated with 180 μm, 60 μm, and 20 μm plankton sizes, were observed at densities of 0 - 1.36 × 103 cfu ml-1, 0 - 8.40 × 102 cfu ml-1 and 0 - 6.80 × 102 cfu ml-1 respectively at the sub-urban community‘s WWTP. In the urban community, counts of culturable vibrios ranged from 0 - 2.80 × 102 cfu ml-1 (180 μm); 0 - 6.60 × 102 cfu ml-1 (60 μm) and 0 -1.80 × 103 cfu ml-1 (20 μm). Abundance of free-living Vibrio species varied between 0 and the orders of 102 and 103 cfu ml-1 in the sub-urban and urban communities WWTPs respectively. Molecular confirmation of the presumptive vibrios isolates revealed the presence of V. fluvialis (41.38 percent), V. vulnificus (34.48 percent), and V. parahaemolyticus (24.14 percent) in the sub-urban community effluents. In the urban community V. fluvialis (40 percent), V. vulnificus (36 percent), and V. parahaemolyticus (24 percent) were detected. There was no significant correlation between Vibrio abundance and season, either as free-living or plankton-associated entities, while Vibrio species abundance correlated positively with temperature (r = 0.565; P < 0.01), salinity and dissolved oxygen (P < 0.05). Turbidity and pH showed significant seasonal variation (P < 0.05) in both locations. The Vibrio strains showed the typical multi-antibiotic-resistance of an SXT element. They were resistant to sulfamethoxazole (Sul), trimethoprim (Tmp), cotrimoxazole (Cot), chloramphenicol (Chl) and streptomycin (Str), as well as other antibiotics such as ampicillin (Amp), penicillin (Pen), erythromycin (Ery), tetracycline (Tet), nalidixic acid (Nal), and gentamicin (Gen). The antibiotic resistance genes detected includes dfr18 and dfrA1 for trimethoprim; tetA, strB, floR, sul2 blaP1, for tetracycline, streptomycin, chloramphenicol, sulfamethoxazole and β-lactams respectively. A number of these genes were only recently described from clinical isolates, demonstrating genetic exchange between clinical and environmental Vibrio species. This study revealed that there was an adverse impact on the physicochemical characteristics of the receiving watershed as a result of the discharge of inadequately treated effluents from the wastewater treatment facilities. The occurrence of Vibrio species as plankton-associated entities confirms the role of plankton as potential reservoir for this pathogen. Also the treated final effluents are reservoirs of various antibiotics resistance genes. This could pose significant health and environmental risk to the biotic component of the environment including communities that rely on the receiving water for domestic purposes and may also affect the health status of the aquatic milieu in the receiving water. There is need for consistent monitoring programme by appropriate regulatory agencies to ensure compliance of the wastewater treatment facilities to regulatory effluent quality standards.
- Full Text:
- Date Issued: 2010
Sustainable agricultural development in the Malawian smallholder agricultural sector: a case of Lilongwe District
- Authors: Chizimba, Martha
- Date: 2010
- Subjects: Food security -- Malawi , Poverty -- Malawi , Sustainable agriculture -- Malawi Case studies , Sustainable development -- Malawi Case studies , Agriculture -- Malawi
- Language: English
- Type: Thesis , Masters , M Soc Sc (Dev)
- Identifier: vital:11420 , http://hdl.handle.net/10353/365 , Food security -- Malawi , Poverty -- Malawi , Sustainable agriculture -- Malawi Case studies , Sustainable development -- Malawi Case studies , Agriculture -- Malawi
- Description: Even though agriculture is the backbone of Malawi‟s economy, food insecurity has remained a continuous threat among the poor. Until the 1980s, Malawi had been achieving national food security through an extensive system of agricultural inputs and marketing subsidies. However, these subsidies were removed and at the same time, the agricultural credit system collapsed. Consequently, agricultural productivity in Malawi remained low, poverty remained pervasive and food insecurity remains a main constraint to national and household food security. Therefore, the success of the agricultural sector in Malawi is very critical for raising the living standards and for food self-sufficiency. In this vein, the study hypothesized that Malawi can only achieve sustainable agricultural development if its agricultural policies are focused towards intensifying agricultural productivity through active participation of smallholder farmers. The major aim of the study was to contribute towards an improved understanding of how the issues of sustainable agricultural development have been addressed in Malawi and how they have influenced the lives of smallholder farmers. The analysis of the results revealed that even though what was implemented in the 1970s to early 1980s was financially unsustainable, but it provided some solutions to the fundamental challenges of smallholder development in Malawi. However, the liberalisations eroded whatever economic benefits achieved then. Never the less, the re-introduction of the agricultural input subsidies restored back the means of production leading to significant transformation of the country from a net importer to a net food exporter. On the other hand, although the agricultural input subsidy programme is being commended for having helped in achieving food security, the study revealed that the programme requires complementary services of credit, extension, research and market to support it. This will provide an exit strategy, which can enable the producers to sell their produce at higher prices sufficient enough for them to afford agricultural inputs without subsidies.
- Full Text:
- Date Issued: 2010
- Authors: Chizimba, Martha
- Date: 2010
- Subjects: Food security -- Malawi , Poverty -- Malawi , Sustainable agriculture -- Malawi Case studies , Sustainable development -- Malawi Case studies , Agriculture -- Malawi
- Language: English
- Type: Thesis , Masters , M Soc Sc (Dev)
- Identifier: vital:11420 , http://hdl.handle.net/10353/365 , Food security -- Malawi , Poverty -- Malawi , Sustainable agriculture -- Malawi Case studies , Sustainable development -- Malawi Case studies , Agriculture -- Malawi
- Description: Even though agriculture is the backbone of Malawi‟s economy, food insecurity has remained a continuous threat among the poor. Until the 1980s, Malawi had been achieving national food security through an extensive system of agricultural inputs and marketing subsidies. However, these subsidies were removed and at the same time, the agricultural credit system collapsed. Consequently, agricultural productivity in Malawi remained low, poverty remained pervasive and food insecurity remains a main constraint to national and household food security. Therefore, the success of the agricultural sector in Malawi is very critical for raising the living standards and for food self-sufficiency. In this vein, the study hypothesized that Malawi can only achieve sustainable agricultural development if its agricultural policies are focused towards intensifying agricultural productivity through active participation of smallholder farmers. The major aim of the study was to contribute towards an improved understanding of how the issues of sustainable agricultural development have been addressed in Malawi and how they have influenced the lives of smallholder farmers. The analysis of the results revealed that even though what was implemented in the 1970s to early 1980s was financially unsustainable, but it provided some solutions to the fundamental challenges of smallholder development in Malawi. However, the liberalisations eroded whatever economic benefits achieved then. Never the less, the re-introduction of the agricultural input subsidies restored back the means of production leading to significant transformation of the country from a net importer to a net food exporter. On the other hand, although the agricultural input subsidy programme is being commended for having helped in achieving food security, the study revealed that the programme requires complementary services of credit, extension, research and market to support it. This will provide an exit strategy, which can enable the producers to sell their produce at higher prices sufficient enough for them to afford agricultural inputs without subsidies.
- Full Text:
- Date Issued: 2010
Sustainable growth of SME's
- Monks, Patrick Grant Standish
- Authors: Monks, Patrick Grant Standish
- Date: 2010
- Subjects: Success in business -- South Africa -- Port Elizabeth , Business enterprises -- South Africa -- Port Elizabeth
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:8627 , http://hdl.handle.net/10948/1488 , Success in business -- South Africa -- Port Elizabeth , Business enterprises -- South Africa -- Port Elizabeth
- Description: South Africa and more specifically Port Elizabeth is faced with many challenges with regard to economic growth and unemployment. It is generally acknowledged that the “Small to Medium Enterprises” (SME) are the largest employers in any economy, additionally SME’s are large contributors to the gross domestic product. Successful SME’s are the catalysts of the economy and over time they can develop into large enterprises. It is clear that in order for a country to have a strong and sustainable economy it needs to have a strong and successful SME sector. Unfortunately the South African SME sector performs relatively poorly in comparison with the SME sectors around the world (Herrington, Kew & Kew, 2009). With the knowledge of the importance of the SME sector to the economy and the knowledge that the South African SME’s are generally underperforming, this study will identify how to improve the relative success rate of the SME sector in Port Elizabeth South Africa. In order to achieve this, this study needs to identify why the SME sector is not performing on a par with other SME sectors from around the globe and what initiatives need to be implemented in Port Elizabeth that will enable its SME sector to perform at the same level or better than other SME sectors from around the globe. This study identifies that the South African SME’s are provided with a number of support initiatives. Some of these support initiatives have been very effective, while other support initiatives have been unsuccessful or have failed. This study concludes by identifying a number of areas that need improvement; of these areas two are identified as being critical to SME’s success and sustainability, these two areas are: · The need to make SME’s more aware of the government / business initiatives that are available; and · Establish more effective mentoring and coaching. In order to address these critical areas, the study suggests the use of an internet portal that can be used to coordinate all the activities between the mentors and the SME’s. This internet portal will be expanded to become the core information hub and collaboration centre for the flow of information between the SME’s and any of their stakeholders. Once all this information is centralised it will be a relatively simple process to measure the success rate of the SME’s and the effectiveness of the different mentors.
- Full Text:
- Date Issued: 2010
- Authors: Monks, Patrick Grant Standish
- Date: 2010
- Subjects: Success in business -- South Africa -- Port Elizabeth , Business enterprises -- South Africa -- Port Elizabeth
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:8627 , http://hdl.handle.net/10948/1488 , Success in business -- South Africa -- Port Elizabeth , Business enterprises -- South Africa -- Port Elizabeth
- Description: South Africa and more specifically Port Elizabeth is faced with many challenges with regard to economic growth and unemployment. It is generally acknowledged that the “Small to Medium Enterprises” (SME) are the largest employers in any economy, additionally SME’s are large contributors to the gross domestic product. Successful SME’s are the catalysts of the economy and over time they can develop into large enterprises. It is clear that in order for a country to have a strong and sustainable economy it needs to have a strong and successful SME sector. Unfortunately the South African SME sector performs relatively poorly in comparison with the SME sectors around the world (Herrington, Kew & Kew, 2009). With the knowledge of the importance of the SME sector to the economy and the knowledge that the South African SME’s are generally underperforming, this study will identify how to improve the relative success rate of the SME sector in Port Elizabeth South Africa. In order to achieve this, this study needs to identify why the SME sector is not performing on a par with other SME sectors from around the globe and what initiatives need to be implemented in Port Elizabeth that will enable its SME sector to perform at the same level or better than other SME sectors from around the globe. This study identifies that the South African SME’s are provided with a number of support initiatives. Some of these support initiatives have been very effective, while other support initiatives have been unsuccessful or have failed. This study concludes by identifying a number of areas that need improvement; of these areas two are identified as being critical to SME’s success and sustainability, these two areas are: · The need to make SME’s more aware of the government / business initiatives that are available; and · Establish more effective mentoring and coaching. In order to address these critical areas, the study suggests the use of an internet portal that can be used to coordinate all the activities between the mentors and the SME’s. This internet portal will be expanded to become the core information hub and collaboration centre for the flow of information between the SME’s and any of their stakeholders. Once all this information is centralised it will be a relatively simple process to measure the success rate of the SME’s and the effectiveness of the different mentors.
- Full Text:
- Date Issued: 2010
Synthesis, characterization and reactions of novel ferrocenylimidazoles as donor ligands
- Authors: Onyancha, Douglas Okerio
- Date: 2010
- Subjects: Ferrocene
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:10390 , http://hdl.handle.net/10948/1150 , Ferrocene
- Description: In this project a series of ferrocenylimidazole derivatives were successfully prepared and characterized using an array of analytical techniques. Reactions of ferrocenylcarbinols with N,N′-thiocarbonyldiimidazole under both solvent-free conditions and in dichloromethane are described. The reaction of ferrocenylmethanol afforded S,S-bis(ferrocenylmethyl)dithiocarbonate, the reaction of α-substituted ferrocenylcarbinols provided ferrocenylalkylimidazolides, while ω-ferrocenylcarbinols yielded ferrocenylimidazolecarbothioates. The reactions were carried out under solvent-free conditions, consistent with the principles of Green Chemistry. Ferrocenyl benzyl ethers were successfully prepared by reacting 4-ferrocenylbenzyl-1Hcarboxylate with a series of primary alcohols under catalytic condition and under a catalyst– free environment. Refluxing a mixture of alcohol-water and 4-ferrocenylbenzyl-1Hcarboxylate provided the corresponding ethers in modest yields. The same ethers were obtained at room temperature by employing potassium tetrachloroplatinate or hydrochloric acid as catalyst. Ferrocenyl-1H-imidazole, 4-ferrocenylphenyl-1H-imidazole and their corresponding ferrocenyl-3-subsitituted imidazolium salts have been successfully synthesized. The compounds were characterized and the electrochemical properties of selected imidazolium salts were examined by cyclic voltammetry. Additionally, X-ray structures of two of the imidazolium salts were determined. The imidazolium salts were found to be good catalysts for the Heck and Suzuki cross-coupling reactions.
- Full Text:
- Date Issued: 2010
- Authors: Onyancha, Douglas Okerio
- Date: 2010
- Subjects: Ferrocene
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:10390 , http://hdl.handle.net/10948/1150 , Ferrocene
- Description: In this project a series of ferrocenylimidazole derivatives were successfully prepared and characterized using an array of analytical techniques. Reactions of ferrocenylcarbinols with N,N′-thiocarbonyldiimidazole under both solvent-free conditions and in dichloromethane are described. The reaction of ferrocenylmethanol afforded S,S-bis(ferrocenylmethyl)dithiocarbonate, the reaction of α-substituted ferrocenylcarbinols provided ferrocenylalkylimidazolides, while ω-ferrocenylcarbinols yielded ferrocenylimidazolecarbothioates. The reactions were carried out under solvent-free conditions, consistent with the principles of Green Chemistry. Ferrocenyl benzyl ethers were successfully prepared by reacting 4-ferrocenylbenzyl-1Hcarboxylate with a series of primary alcohols under catalytic condition and under a catalyst– free environment. Refluxing a mixture of alcohol-water and 4-ferrocenylbenzyl-1Hcarboxylate provided the corresponding ethers in modest yields. The same ethers were obtained at room temperature by employing potassium tetrachloroplatinate or hydrochloric acid as catalyst. Ferrocenyl-1H-imidazole, 4-ferrocenylphenyl-1H-imidazole and their corresponding ferrocenyl-3-subsitituted imidazolium salts have been successfully synthesized. The compounds were characterized and the electrochemical properties of selected imidazolium salts were examined by cyclic voltammetry. Additionally, X-ray structures of two of the imidazolium salts were determined. The imidazolium salts were found to be good catalysts for the Heck and Suzuki cross-coupling reactions.
- Full Text:
- Date Issued: 2010
Systemic influence on Black South African adolescents' career development : adolescent and parental perspectives
- Authors: Collett, Gary Reece
- Date: 2010
- Subjects: Career development -- South Africa , Teenagers -- Vocational guidance , Adolescence , Parent and child
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:9863 , http://hdl.handle.net/10948/1513 , Career development -- South Africa , Teenagers -- Vocational guidance , Adolescence , Parent and child
- Description: Currently, no career theories exist that sufficiently explain the career development of South Africa’s diverse population groups. Consequently, South African researchers have been entirely dependent on international, western-informed career theories. While such theories have taken on a more ethnocentric complexion in recent times, they remain essentially decontextualised for South Africa. Furthermore, although the influence of family and the significant roles of parents have been theoretically acknowledged as critical influences in adolescent career development, there is still a considerable lack of research in South Africa on this topic. The present study therefore explored the perceptions of systemic influences on adolescent career development from the perspectives of both Black middle-class South African Grade 11 learners and their parents. The research was conceptualised within the Systems Theory Framework (STF) of career development and used its derivative instrument, the My Systems of Career Influences (MSCI, Adolescent). The present study utilised a qualitative research method, using answers derived from the MSCI (Adolescent) booklets to inform semi-structured interviews. The data analysis procedure involved the use of Interpretive Phenomenological Analysis to qualitatively analyse data obtained from the semistructured interviews. Findings revealed a number of influences within the individual system (personality, values, abilities), social system (adolescents’ parents and teachers) and societal-environmental system (financial support, the opportunity to work overseas, geographical location, job availability, and the location of universities) that were acknowledged as having an influence on the career development of South African Black middle class adolescents. Each of these findings were explored and unpacked under the four xii identified Interpretive Phenomenological Analysis (IPA) superordinate themes of Family Dynamics, Great Expectations, The Ghost of Apartheid and Coconuts Fall Far From the Tree. Lastly, the limitations of the present study, as well as recommendations for future research are discussed.
- Full Text:
- Date Issued: 2010
- Authors: Collett, Gary Reece
- Date: 2010
- Subjects: Career development -- South Africa , Teenagers -- Vocational guidance , Adolescence , Parent and child
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:9863 , http://hdl.handle.net/10948/1513 , Career development -- South Africa , Teenagers -- Vocational guidance , Adolescence , Parent and child
- Description: Currently, no career theories exist that sufficiently explain the career development of South Africa’s diverse population groups. Consequently, South African researchers have been entirely dependent on international, western-informed career theories. While such theories have taken on a more ethnocentric complexion in recent times, they remain essentially decontextualised for South Africa. Furthermore, although the influence of family and the significant roles of parents have been theoretically acknowledged as critical influences in adolescent career development, there is still a considerable lack of research in South Africa on this topic. The present study therefore explored the perceptions of systemic influences on adolescent career development from the perspectives of both Black middle-class South African Grade 11 learners and their parents. The research was conceptualised within the Systems Theory Framework (STF) of career development and used its derivative instrument, the My Systems of Career Influences (MSCI, Adolescent). The present study utilised a qualitative research method, using answers derived from the MSCI (Adolescent) booklets to inform semi-structured interviews. The data analysis procedure involved the use of Interpretive Phenomenological Analysis to qualitatively analyse data obtained from the semistructured interviews. Findings revealed a number of influences within the individual system (personality, values, abilities), social system (adolescents’ parents and teachers) and societal-environmental system (financial support, the opportunity to work overseas, geographical location, job availability, and the location of universities) that were acknowledged as having an influence on the career development of South African Black middle class adolescents. Each of these findings were explored and unpacked under the four xii identified Interpretive Phenomenological Analysis (IPA) superordinate themes of Family Dynamics, Great Expectations, The Ghost of Apartheid and Coconuts Fall Far From the Tree. Lastly, the limitations of the present study, as well as recommendations for future research are discussed.
- Full Text:
- Date Issued: 2010
Target costing as a strategic cost management tool in the South African motor industry
- Authors: Slater, Michael, M A
- Date: 2010
- Subjects: Target costing -- South Africa , Strategic planning -- South Africa -- Management , Cost accounting -- South Africa -- Standards , Cost accounting -- South Africa , Cost control
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:8974 , http://hdl.handle.net/10948/1094 , Target costing -- South Africa , Strategic planning -- South Africa -- Management , Cost accounting -- South Africa -- Standards , Cost accounting -- South Africa , Cost control
- Description: Traditional cost-accounting approaches have served manufacturers well over a long period, but due to the changing nature of the modern manufacturing environment shortcomings have resulted and are no longer regarded as suitable (Gagne & Discenza 1993: 68). Similarly, Monden and Lee (1993: 22) state that many practitioners and academicians have questioned the effectiveness of standard cost systems, which have been used as the primary cost control measure for the last several decades. Cooper and Slagmulder (1997: 2) point out that in contrast to the conventional cost management techniques, target costing adopts a feed-forward approach. The objective of target costing is to design costs out of products, and not to find ways of eliminating costs after the products enter production. Few firms can afford to ignore such a powerful mechanism to increase profits in today’s highly competitive environment.
- Full Text:
- Date Issued: 2010
- Authors: Slater, Michael, M A
- Date: 2010
- Subjects: Target costing -- South Africa , Strategic planning -- South Africa -- Management , Cost accounting -- South Africa -- Standards , Cost accounting -- South Africa , Cost control
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:8974 , http://hdl.handle.net/10948/1094 , Target costing -- South Africa , Strategic planning -- South Africa -- Management , Cost accounting -- South Africa -- Standards , Cost accounting -- South Africa , Cost control
- Description: Traditional cost-accounting approaches have served manufacturers well over a long period, but due to the changing nature of the modern manufacturing environment shortcomings have resulted and are no longer regarded as suitable (Gagne & Discenza 1993: 68). Similarly, Monden and Lee (1993: 22) state that many practitioners and academicians have questioned the effectiveness of standard cost systems, which have been used as the primary cost control measure for the last several decades. Cooper and Slagmulder (1997: 2) point out that in contrast to the conventional cost management techniques, target costing adopts a feed-forward approach. The objective of target costing is to design costs out of products, and not to find ways of eliminating costs after the products enter production. Few firms can afford to ignore such a powerful mechanism to increase profits in today’s highly competitive environment.
- Full Text:
- Date Issued: 2010
TB treatment initiation and adherence in a South African community influenced more by perceptions than by knowledge of tuberculosis
- Cramm, Jane M, Finkenflügel, Harry J M, Moller, Valerie, Nieboer, Anna P
- Authors: Cramm, Jane M , Finkenflügel, Harry J M , Moller, Valerie , Nieboer, Anna P
- Date: 2010
- Language: English
- Type: Article
- Identifier: vital:7101 , http://hdl.handle.net/10962/d1010657
- Description: Background Tuberculosis (TB) is a global health concern. Inadequate case finding and case holding has been cited as major barrier to the control of TB. The TB literature is written almost entirely from a biomedical perspective, while recent studies show that it is imperative to understand lay perception to determine why people seek treatment and may stop taking treatment. The Eastern Cape is known as a province with high TB incidence, prevalence and with one of the worst cure rates of South Africa. Its inhabitants can be considered lay experts when it comes to TB. Therefore, we investigated knowledge, perceptions of (access to) TB treatment and adherence to treatment among an Eastern Cape population. Methods An area-stratified sampling design was applied. A total of 1020 households were selected randomly in proportion to the total number of households in each neighbourhood. Results TB knowledge can be considered fairly good among this community. Respondents' perceptions suggest that stigma may influence TB patients' decision in health seeking behavior and adherence to TB treatment. A full 95 percent of those interviewed believe people with TB tend to hide their TB status out of fear of what others may say. Regression analyses revealed that in this population young and old, men and women and the lower and higher educated share the same attitudes and perceptions. Our findings are therefore likely to reflect the actual situation of TB patients in this population. Conclusions The lay experts' perceptions suggests that stigma appears to effect case holding and case finding. Future interventions should be directed at improving attitudes and perceptions to potentially reduce stigma. This requires a patient-centered approach to empower TB patients and active involvement in the development and implementation of stigma reduction programs.
- Full Text:
- Date Issued: 2010
- Authors: Cramm, Jane M , Finkenflügel, Harry J M , Moller, Valerie , Nieboer, Anna P
- Date: 2010
- Language: English
- Type: Article
- Identifier: vital:7101 , http://hdl.handle.net/10962/d1010657
- Description: Background Tuberculosis (TB) is a global health concern. Inadequate case finding and case holding has been cited as major barrier to the control of TB. The TB literature is written almost entirely from a biomedical perspective, while recent studies show that it is imperative to understand lay perception to determine why people seek treatment and may stop taking treatment. The Eastern Cape is known as a province with high TB incidence, prevalence and with one of the worst cure rates of South Africa. Its inhabitants can be considered lay experts when it comes to TB. Therefore, we investigated knowledge, perceptions of (access to) TB treatment and adherence to treatment among an Eastern Cape population. Methods An area-stratified sampling design was applied. A total of 1020 households were selected randomly in proportion to the total number of households in each neighbourhood. Results TB knowledge can be considered fairly good among this community. Respondents' perceptions suggest that stigma may influence TB patients' decision in health seeking behavior and adherence to TB treatment. A full 95 percent of those interviewed believe people with TB tend to hide their TB status out of fear of what others may say. Regression analyses revealed that in this population young and old, men and women and the lower and higher educated share the same attitudes and perceptions. Our findings are therefore likely to reflect the actual situation of TB patients in this population. Conclusions The lay experts' perceptions suggests that stigma appears to effect case holding and case finding. Future interventions should be directed at improving attitudes and perceptions to potentially reduce stigma. This requires a patient-centered approach to empower TB patients and active involvement in the development and implementation of stigma reduction programs.
- Full Text:
- Date Issued: 2010
The adoption of quality assurance in e-Health acquisition for rural hospitals in the Eastern Cape Province
- Authors: Ruxwana, Nkqubela
- Date: 2010
- Subjects: Quality assurance -- Management , Hospital care -- Quality control , Health facilities -- Quality control , Health -- Computer network resources , Public health -- Information services
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:9731 , http://hdl.handle.net/10948/1514 , Quality assurance -- Management , Hospital care -- Quality control , Health facilities -- Quality control , Health -- Computer network resources , Public health -- Information services
- Description: The evolution of e-health has the potential to assist in the management of scarce resources and the shortage of skills, enhance efficiencies, improve quality and increase work productivity within the healthcare sector. As a result, an increase is seen in e-health solutions developments with the aim to improve healthcare services, hospital information systems, health decision support, telemedicine and other technical systems that have the potential to reduce cost, improve quality, and enhance the accessibility and delivery of healthcare. However, unfortunately their implementation contiues to fail. Although there are several reasons for this, in this study a lack of project quality management is viewed as a key contributor to the failure of e-health solutions implementation projects in rural hospitals. This results in neglected aspects of quality assurance (QA), which forms an integral part of project quality management. The purpose of this study is to develop a Genertic Quality Assurance Model (GQAM) for the successful acquisition (i.e. development and implementation) of e-health solutions in rural hospitals in the Eastern Cape Province to enable improved quality of care and service delivery. In order to develop and test this model it was necessary to identify the QA methodologies that are currently used in rural hospitals and to evaluate their strengths and weaknesses, as well as their impact on project success. The study is divided into four phases; in each phase different study designs were followed. The study used triangulation of qualitative and some elements of quantitative research approaches, in terms of which a case study approach was adpoted to answer the research questions. This study did indeed develop a GQAM that can be used to ensure e-health solution success in rural hospitals. Furthermore, to aid in the implementation of this model, a set of QA value chain implementation guidelines were developed, as a framework, to inject the nodel into typical (SDLC) phases.
- Full Text:
- Date Issued: 2010
- Authors: Ruxwana, Nkqubela
- Date: 2010
- Subjects: Quality assurance -- Management , Hospital care -- Quality control , Health facilities -- Quality control , Health -- Computer network resources , Public health -- Information services
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:9731 , http://hdl.handle.net/10948/1514 , Quality assurance -- Management , Hospital care -- Quality control , Health facilities -- Quality control , Health -- Computer network resources , Public health -- Information services
- Description: The evolution of e-health has the potential to assist in the management of scarce resources and the shortage of skills, enhance efficiencies, improve quality and increase work productivity within the healthcare sector. As a result, an increase is seen in e-health solutions developments with the aim to improve healthcare services, hospital information systems, health decision support, telemedicine and other technical systems that have the potential to reduce cost, improve quality, and enhance the accessibility and delivery of healthcare. However, unfortunately their implementation contiues to fail. Although there are several reasons for this, in this study a lack of project quality management is viewed as a key contributor to the failure of e-health solutions implementation projects in rural hospitals. This results in neglected aspects of quality assurance (QA), which forms an integral part of project quality management. The purpose of this study is to develop a Genertic Quality Assurance Model (GQAM) for the successful acquisition (i.e. development and implementation) of e-health solutions in rural hospitals in the Eastern Cape Province to enable improved quality of care and service delivery. In order to develop and test this model it was necessary to identify the QA methodologies that are currently used in rural hospitals and to evaluate their strengths and weaknesses, as well as their impact on project success. The study is divided into four phases; in each phase different study designs were followed. The study used triangulation of qualitative and some elements of quantitative research approaches, in terms of which a case study approach was adpoted to answer the research questions. This study did indeed develop a GQAM that can be used to ensure e-health solution success in rural hospitals. Furthermore, to aid in the implementation of this model, a set of QA value chain implementation guidelines were developed, as a framework, to inject the nodel into typical (SDLC) phases.
- Full Text:
- Date Issued: 2010
The advent of the 'Festivore' an exploration of South African audience attendance in the performing arts at the National Arts Festival
- Authors: Antrobus, Richard Roy
- Date: 2010
- Subjects: Standard Bank National Arts Festival -- Economic aspects , Arts -- Economic aspects , Performing arts festivals -- Economic aspects -- South Africa -- Grahamstown , Arts -- South Africa -- Economic aspects , Arts -- South Africa -- Finance , Arts -- South Africa -- Political aspects , Arts audiences -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2130 , http://hdl.handle.net/10962/d1002362
- Description: In South Africa, the performing arts have contributed to enhancing national identity and distinctiveness despite coming up against weak legislation, policy and infrastructure to support their growth and proliferation (Fredericks, 2005: 9). Coupled with a decline in both government and consumer support and the contradictory disparity between valuing the arts and the funding of the arts, theatre companies can no longer rely on the comfort of external subsidies and financial support. In order to be economically viable and sustainable to ensure their survival, there is an increasing demand for theatre companies to look to novel ways of increasing audience demand for theatre and improving audience attendance. However, instead of risking artistic integrity and the performance product to satisfy the market, this research suggests that promotion and development of theatre at arts festivals provides a platform to access a wider theatre-going public, which therefore facilitates a change in the market focus toward appreciation of the product (production). It explores leading arguments pertaining to the attendance of arts and cultural events, namely, Peterson and Simkus (1992), later updated by Peterson‟s (2005)„omnivore-univore‟ argument. The argument purports cultural consumption as binary in nature: either significant and diverse or limited, if not absent altogether. Supported by a number of case-studies, including Chan and Goldthorpe (2005) and Montgomery and Robinson (2008) and Snowball et al. (2009), the investigation challenges Bourdieu‟s (1984) theory on cultural distinction as well as the homology and individualisation argument. In determining the factors that influence cultural taste and consumer behaviour, including motivators and inhibitors of attendance and a predominant emphasis on audience risk and information asymmetry, the research was placed in a local context, providing an overview of the socio-economic theatre environment in South Africa. It investigated the nature, structure and impact of local festivals (as events) in changing audience demand and theatre attendance. With specific reference to the South African National Arts Festival (NAF) the research notes the effects of Hauptfleisch‟s „eventification‟ phenomenon on univore attenders and therefore expands the omnivore-univore theory to include a new breed of attender: the “Festivore”. A case study explored the “Festivore” hypothesis through empirical research, surveys and face-to-face qualitative interviews and on-seat questionnaire responses by festival attenders. Personal interviews and communication was also carried out with leading experts in the field. The data was then analysed using SPSS 13 electronic statistical analysis programme to determine the socio-demographics and the factors that affect theatre attendance of existing, as well as potential target, theatre audiences at the National Arts Festival The study concluded that South African theatre attenders are generally omnivorous consumers and that, more importantly, there seems to be a shift towards „festivorous‟ consumption. Furthermore, evidence supports the development and proliferation of festivals as a means not only to support and promote the arts in South Africa but, more importantly, to generate new theatre audiences and entrench theatre attendance into South African culture.
- Full Text:
- Date Issued: 2010
- Authors: Antrobus, Richard Roy
- Date: 2010
- Subjects: Standard Bank National Arts Festival -- Economic aspects , Arts -- Economic aspects , Performing arts festivals -- Economic aspects -- South Africa -- Grahamstown , Arts -- South Africa -- Economic aspects , Arts -- South Africa -- Finance , Arts -- South Africa -- Political aspects , Arts audiences -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2130 , http://hdl.handle.net/10962/d1002362
- Description: In South Africa, the performing arts have contributed to enhancing national identity and distinctiveness despite coming up against weak legislation, policy and infrastructure to support their growth and proliferation (Fredericks, 2005: 9). Coupled with a decline in both government and consumer support and the contradictory disparity between valuing the arts and the funding of the arts, theatre companies can no longer rely on the comfort of external subsidies and financial support. In order to be economically viable and sustainable to ensure their survival, there is an increasing demand for theatre companies to look to novel ways of increasing audience demand for theatre and improving audience attendance. However, instead of risking artistic integrity and the performance product to satisfy the market, this research suggests that promotion and development of theatre at arts festivals provides a platform to access a wider theatre-going public, which therefore facilitates a change in the market focus toward appreciation of the product (production). It explores leading arguments pertaining to the attendance of arts and cultural events, namely, Peterson and Simkus (1992), later updated by Peterson‟s (2005)„omnivore-univore‟ argument. The argument purports cultural consumption as binary in nature: either significant and diverse or limited, if not absent altogether. Supported by a number of case-studies, including Chan and Goldthorpe (2005) and Montgomery and Robinson (2008) and Snowball et al. (2009), the investigation challenges Bourdieu‟s (1984) theory on cultural distinction as well as the homology and individualisation argument. In determining the factors that influence cultural taste and consumer behaviour, including motivators and inhibitors of attendance and a predominant emphasis on audience risk and information asymmetry, the research was placed in a local context, providing an overview of the socio-economic theatre environment in South Africa. It investigated the nature, structure and impact of local festivals (as events) in changing audience demand and theatre attendance. With specific reference to the South African National Arts Festival (NAF) the research notes the effects of Hauptfleisch‟s „eventification‟ phenomenon on univore attenders and therefore expands the omnivore-univore theory to include a new breed of attender: the “Festivore”. A case study explored the “Festivore” hypothesis through empirical research, surveys and face-to-face qualitative interviews and on-seat questionnaire responses by festival attenders. Personal interviews and communication was also carried out with leading experts in the field. The data was then analysed using SPSS 13 electronic statistical analysis programme to determine the socio-demographics and the factors that affect theatre attendance of existing, as well as potential target, theatre audiences at the National Arts Festival The study concluded that South African theatre attenders are generally omnivorous consumers and that, more importantly, there seems to be a shift towards „festivorous‟ consumption. Furthermore, evidence supports the development and proliferation of festivals as a means not only to support and promote the arts in South Africa but, more importantly, to generate new theatre audiences and entrench theatre attendance into South African culture.
- Full Text:
- Date Issued: 2010
The applicability of the promotion of Administrative Justice Act in review of CCMA arbitration awards
- Phanyane, Namadzavho California
- Authors: Phanyane, Namadzavho California
- Date: 2010
- Subjects: Arbitration (Administrative law) -- South Africa , Arbitration and award -- Law and legislation -- South Africa
- Language: English
- Type: Thesis , Masters , LLM
- Identifier: vital:10219 , http://hdl.handle.net/10948/1282 , Arbitration (Administrative law) -- South Africa , Arbitration and award -- Law and legislation -- South Africa
- Description: South Africa’s employment law has undergone more frequent and dynamic changes than any area of the law, in recent years. The ability of employers and employees to regulate their respective rights and duties vis-à-vis each other by independent agreement has been progressively whittled down by statutory intervention. In so limiting the capacity of parties to the employment relationship to regulate the nature of their relationship, South Africa has followed development in Western industrialised nations. Against this background, the drafters of the Labour Relations Act1 (LRA), as amended, proposed a comprehensive framework of law governing the collective relations between employers and trade unions in all sectors of the economy. The LRA2 created a specialised set of forums and tribunals to deal with labour and employment related matters. It established Bargaining Councils, the Commission for Conciliation Mediation and Arbitration (CCMA), the Labour Court (LC) and the Labour Appeal Court (LAC). It also created procedures designed to accomplish the objective of simple, inexpensive and accessible resolution of labour disputes. In redesigning labour law, the legislature decided that some disputes between employers and employees should be dealt with by arbitrators and others by judges. It is this distinction that resulted in the creation of the CCMA and the Labour Court to perform arbitration and adjudication respectively. The result of adjudication is generally subject to appeal to a higher court. The result of arbitration is generally subject to review. Arbitration was given statutory recognition in South Africa by the Arbitration Act3. That Act provides a framework within which parties in dispute may if they wish appoint their own “judge” and supply him or her with their terms of reference tailored to their needs. With the foregoing in mind, the purpose of this work is the provision of a selection of landmark cases that dealt with the review function of CCMA awards. This selection 1 Act 66 of 1995 as amended comprises of landmark judgments of the different courts of the land. The study uses, as it departure point, legislative framework to elicit the extent to which review is extended to the litigants. Apart from looking at the legislative provisions towards review grounds, reference is made to specific landmark judgments that have an effect on this subject in order to provide a comprehensive and explicit picture of how CCMA arbitration awards may be taken on review. This study focuses on substantive law developed by the Labour Court, High Court, Supreme Court of Appeal and finally the Constitutional Court. This is informed by the very nature and scope of the study because any concentration on procedural and evidentiary aspects of review could lead to failure to achieve the objectives of the study. It looks at specific South African case law, judgments of the courts and the jurisprudence in the field of employment law so that the reader is presented with a clearer picture of recent developments in addressing review of arbitration awards. The concluding remarks are drawn from a variety of approaches used by the authorities in the field of employment law in dealing with review of CCMA arbitration awards and issues for further research are highlighted.
- Full Text:
- Date Issued: 2010
- Authors: Phanyane, Namadzavho California
- Date: 2010
- Subjects: Arbitration (Administrative law) -- South Africa , Arbitration and award -- Law and legislation -- South Africa
- Language: English
- Type: Thesis , Masters , LLM
- Identifier: vital:10219 , http://hdl.handle.net/10948/1282 , Arbitration (Administrative law) -- South Africa , Arbitration and award -- Law and legislation -- South Africa
- Description: South Africa’s employment law has undergone more frequent and dynamic changes than any area of the law, in recent years. The ability of employers and employees to regulate their respective rights and duties vis-à-vis each other by independent agreement has been progressively whittled down by statutory intervention. In so limiting the capacity of parties to the employment relationship to regulate the nature of their relationship, South Africa has followed development in Western industrialised nations. Against this background, the drafters of the Labour Relations Act1 (LRA), as amended, proposed a comprehensive framework of law governing the collective relations between employers and trade unions in all sectors of the economy. The LRA2 created a specialised set of forums and tribunals to deal with labour and employment related matters. It established Bargaining Councils, the Commission for Conciliation Mediation and Arbitration (CCMA), the Labour Court (LC) and the Labour Appeal Court (LAC). It also created procedures designed to accomplish the objective of simple, inexpensive and accessible resolution of labour disputes. In redesigning labour law, the legislature decided that some disputes between employers and employees should be dealt with by arbitrators and others by judges. It is this distinction that resulted in the creation of the CCMA and the Labour Court to perform arbitration and adjudication respectively. The result of adjudication is generally subject to appeal to a higher court. The result of arbitration is generally subject to review. Arbitration was given statutory recognition in South Africa by the Arbitration Act3. That Act provides a framework within which parties in dispute may if they wish appoint their own “judge” and supply him or her with their terms of reference tailored to their needs. With the foregoing in mind, the purpose of this work is the provision of a selection of landmark cases that dealt with the review function of CCMA awards. This selection 1 Act 66 of 1995 as amended comprises of landmark judgments of the different courts of the land. The study uses, as it departure point, legislative framework to elicit the extent to which review is extended to the litigants. Apart from looking at the legislative provisions towards review grounds, reference is made to specific landmark judgments that have an effect on this subject in order to provide a comprehensive and explicit picture of how CCMA arbitration awards may be taken on review. This study focuses on substantive law developed by the Labour Court, High Court, Supreme Court of Appeal and finally the Constitutional Court. This is informed by the very nature and scope of the study because any concentration on procedural and evidentiary aspects of review could lead to failure to achieve the objectives of the study. It looks at specific South African case law, judgments of the courts and the jurisprudence in the field of employment law so that the reader is presented with a clearer picture of recent developments in addressing review of arbitration awards. The concluding remarks are drawn from a variety of approaches used by the authorities in the field of employment law in dealing with review of CCMA arbitration awards and issues for further research are highlighted.
- Full Text:
- Date Issued: 2010
The biology of austroglanis gilli and austroglanis barnardi (siluriformes : austroglanididae) in the Olifants River system, South Africa
- Authors: Mthombeni, Vusi Gedla
- Date: 2010
- Subjects: Catfishes -- South Africa -- Olifants River , Fishes -- South Africa -- Olifants River -- Growth , Freshwater fishes -- Effect of pesticides on -- South Africa -- Olifants River
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5370 , http://hdl.handle.net/10962/d1015222
- Description: Austroglanis gilli and A. barnardi are endemic to the Clanwilliam-Olifants System in the Western Cape, South Africa. The populations of each of these species are considered to be threatened by various anthropogenic activities, which include inappropriate agricultural practice and impacts of alien invasive fish species. The purpose of this thesis was to assess the life-history of these two endangered species in order to contribute to understanding their biology. Such information is vital for the development of strategies for their conservation. Marginal zone and marginal increment analyses from sectioned lapilliar otoliths of both A. gilli and A. barnardi showed a unimodal peak, suggesting a single annulus formation. The oldest specimens of A. gilli and A. barnardi were 12+ and 14+ years, respectively. The growth of A. gilli and A. barnardi was relatively slow and was best described by the von Bertalanffy growth curve as: L, = 131.56(1 - exp(- 0.27(t - 1.18 ))) for male and L, = 113.86(1 - exp(- 0.43(1- 0.74))) for female A. gilli from the Rondegat River. In the Noordhoeks River, growth was L, = 99.67(1 - exp(- 0.53(t - 0.35))) for male and L, = 96.60(1 - exp(- 0.64(t - 0.11 ))) for female A. gilli, and L, =71.02(1-exp(-0.26(1-3.07))) and L, = 69.50(1-exp(-0.36(1 - 1.88))) for male and female A. barnardi, respectively. The average natural mortality for the combined sexes was estimated using catch curve analysis at 0.37 ± 0.12 per year for A. gilli from the Rondegat River, and at 0.71 ± 0.05 and 0.39 ± 0.04 per year for A. gilli and A. barnardi from the Noordhoeks River, respectively. For A. gilli in the Rondegat River, the first maturity was estimated at 3.3 years (97.3 mm SL) for males and 3.1 years (94.3 mm SL) for females. In the Noordhoeks River, the first maturity for A. gilli was estimated at 2.0 years (71.9 mm SL) for males and 1.7 (66.4 mm SL) for females, and for A. barnardi at 2.0 (55.0 nun SL) for males and 2.9 years (58.9 mm SL) for females. Maturity corresponded closely to the asymptotic sizes from the von Bertalanffy curves, suggesting a shift in energy use from somatic growth to gonad development. Macroscopic assessment of the state of gonads, the Ganado-somatic index and histological examinations revealed that both A. gilli and A. barnardi have a single spawning season. The presence of oocytes in different stages of development in each of the ovaries of mature females collected between November and January suggested asynchronous, iteroperous serial spawning. The resorption of yolk was observed from ovaries collected between February and March and no vitellogenic oocyte was visible from ovaries collected between April and August. A similar trend was observed for males, with spermatozoa filling the lumen between November and January and some residual spermatozoa being present in the lumens soon after the breeding season. Spermatocytes and spermatids were dominant in the testes until October. An Index of Relative Importance revealed that A. gilli feeds predominantly on the benthic macroinvertebrate larvae of Ephemeroptera (particularly Baetidae), Diptera (particularly Chironomidae and Simuliidae) and Trichoptera. Austroglanis barnardi feeds predominantly on dipteran larvae (particularly Chironornidae and Simuliidae). Chi square contingency tables showed a significant difference in the dominant prey items of A. gilli and A. barnardi in the Noordhoeks River (X₂= 53.79, d.f. = 4, p > 0.001) and A. gilli between Rondegat and Noordhoeks rivers (x₂ = 34.74, d.f. = 4, p > 0.001). The Spearman's rank correlation test showed no shifts in the diet of A. barnardi from Noordhoeks River and A. gilli from Rondegat River with a change in size and season (p>O.OS). However, there was a shift in the diet of A. gilli from the Noordhoeks River which could suggest a distinct patchiness of benthic macroinvertebrates between the riffle feeding areas used by juveniles and other biotopes used by adults. The occurrence, in stomach contents, of other prey items from a wide variety of taxa and the presence of allochthonous material from the terrestrial environment could suggest an opportunistic feeding guild for both Austroglanis species. The life-history traits of A. gilli and A. barnardi, which are charaterized by slow growth, long life span and low relative fecundity, indicate that both species are relatively precocial and K-selected. The population of a precocial species is relatively stable and if population numbers were to be greatly reduced, they would require a long time to rebuild. An urgent conservation intervention is therefore recommended for Austroglanis spp. so as to maintain the diversity of populations within these species. The creation of protected river reserves and raising public conservation awareness may minimise activities that result in altered river hydrology and the destruction of complex benthic habitats.
- Full Text:
- Date Issued: 2010
- Authors: Mthombeni, Vusi Gedla
- Date: 2010
- Subjects: Catfishes -- South Africa -- Olifants River , Fishes -- South Africa -- Olifants River -- Growth , Freshwater fishes -- Effect of pesticides on -- South Africa -- Olifants River
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5370 , http://hdl.handle.net/10962/d1015222
- Description: Austroglanis gilli and A. barnardi are endemic to the Clanwilliam-Olifants System in the Western Cape, South Africa. The populations of each of these species are considered to be threatened by various anthropogenic activities, which include inappropriate agricultural practice and impacts of alien invasive fish species. The purpose of this thesis was to assess the life-history of these two endangered species in order to contribute to understanding their biology. Such information is vital for the development of strategies for their conservation. Marginal zone and marginal increment analyses from sectioned lapilliar otoliths of both A. gilli and A. barnardi showed a unimodal peak, suggesting a single annulus formation. The oldest specimens of A. gilli and A. barnardi were 12+ and 14+ years, respectively. The growth of A. gilli and A. barnardi was relatively slow and was best described by the von Bertalanffy growth curve as: L, = 131.56(1 - exp(- 0.27(t - 1.18 ))) for male and L, = 113.86(1 - exp(- 0.43(1- 0.74))) for female A. gilli from the Rondegat River. In the Noordhoeks River, growth was L, = 99.67(1 - exp(- 0.53(t - 0.35))) for male and L, = 96.60(1 - exp(- 0.64(t - 0.11 ))) for female A. gilli, and L, =71.02(1-exp(-0.26(1-3.07))) and L, = 69.50(1-exp(-0.36(1 - 1.88))) for male and female A. barnardi, respectively. The average natural mortality for the combined sexes was estimated using catch curve analysis at 0.37 ± 0.12 per year for A. gilli from the Rondegat River, and at 0.71 ± 0.05 and 0.39 ± 0.04 per year for A. gilli and A. barnardi from the Noordhoeks River, respectively. For A. gilli in the Rondegat River, the first maturity was estimated at 3.3 years (97.3 mm SL) for males and 3.1 years (94.3 mm SL) for females. In the Noordhoeks River, the first maturity for A. gilli was estimated at 2.0 years (71.9 mm SL) for males and 1.7 (66.4 mm SL) for females, and for A. barnardi at 2.0 (55.0 nun SL) for males and 2.9 years (58.9 mm SL) for females. Maturity corresponded closely to the asymptotic sizes from the von Bertalanffy curves, suggesting a shift in energy use from somatic growth to gonad development. Macroscopic assessment of the state of gonads, the Ganado-somatic index and histological examinations revealed that both A. gilli and A. barnardi have a single spawning season. The presence of oocytes in different stages of development in each of the ovaries of mature females collected between November and January suggested asynchronous, iteroperous serial spawning. The resorption of yolk was observed from ovaries collected between February and March and no vitellogenic oocyte was visible from ovaries collected between April and August. A similar trend was observed for males, with spermatozoa filling the lumen between November and January and some residual spermatozoa being present in the lumens soon after the breeding season. Spermatocytes and spermatids were dominant in the testes until October. An Index of Relative Importance revealed that A. gilli feeds predominantly on the benthic macroinvertebrate larvae of Ephemeroptera (particularly Baetidae), Diptera (particularly Chironomidae and Simuliidae) and Trichoptera. Austroglanis barnardi feeds predominantly on dipteran larvae (particularly Chironornidae and Simuliidae). Chi square contingency tables showed a significant difference in the dominant prey items of A. gilli and A. barnardi in the Noordhoeks River (X₂= 53.79, d.f. = 4, p > 0.001) and A. gilli between Rondegat and Noordhoeks rivers (x₂ = 34.74, d.f. = 4, p > 0.001). The Spearman's rank correlation test showed no shifts in the diet of A. barnardi from Noordhoeks River and A. gilli from Rondegat River with a change in size and season (p>O.OS). However, there was a shift in the diet of A. gilli from the Noordhoeks River which could suggest a distinct patchiness of benthic macroinvertebrates between the riffle feeding areas used by juveniles and other biotopes used by adults. The occurrence, in stomach contents, of other prey items from a wide variety of taxa and the presence of allochthonous material from the terrestrial environment could suggest an opportunistic feeding guild for both Austroglanis species. The life-history traits of A. gilli and A. barnardi, which are charaterized by slow growth, long life span and low relative fecundity, indicate that both species are relatively precocial and K-selected. The population of a precocial species is relatively stable and if population numbers were to be greatly reduced, they would require a long time to rebuild. An urgent conservation intervention is therefore recommended for Austroglanis spp. so as to maintain the diversity of populations within these species. The creation of protected river reserves and raising public conservation awareness may minimise activities that result in altered river hydrology and the destruction of complex benthic habitats.
- Full Text:
- Date Issued: 2010
The biotechnology of hard coal utilization as a bioprocess substrate
- Mutambanengwe, Cecil Clifford Zvandada
- Authors: Mutambanengwe, Cecil Clifford Zvandada
- Date: 2010
- Subjects: Coal -- Biotechnology Acid mine drainage Coal mines and mining -- Environmental aspects
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3934 , http://hdl.handle.net/10962/d1003993
- Description: The development of coal biotechnology, using hard coal as a substrate, has been impeded by its low reactivity in biological processes. As a result, the more successful application studies have focused on lignitic soft coals. However, new studies have reported using biologically or geologically oxidized hard coal as a functional substrate option for bioprocess applications on a large scale. This study undertook a preliminary investigation into the feasibility of environmental applications of coal biotechnology using oxidized hard coal substrates in both anaerobic and aerobic processes with carbon dioxide, sulfate and oxygen as terminal electron acceptors. A preliminary characterization of the oxidized hard coal substrates was undertaken to determine and predict their viability and behavior as electron donors and carbon sources for environmental bioprocess applications of direct interest to the coal mining industry. Both biologically and geologically oxidized coal substrates showed loss of up to 17% and 52% carbon respectively and incorporation of oxygen ranging from 0.9 – 24%. The latter substrate showed greater loss of carbon and increased oxygenation. The biologically and geologically oxidized hard coal substrates were shown to partition readily into 23% and 32% organic humic acid, a 0.1% fulvic acid fraction and 65% and 59% inorganic and humin fractions respectively. These organic components were shown to be potentially available for biological consumption. In the unmodified hard coal substrate, partitioning was not observed and it did not perform as a functional substrate for any of the bioprocesses investigated. Where carbon dioxide was used as a terminal electron acceptor, methane production ranging from 9 – 26 mg CH4.g substrate-1 was demonstrated from both oxidized coal substrates. Geologically oxidized coal produced 30% more methane than biologically oxidized coal. Methane yields from the geologically oxidized coal in the presence and absence of a co-substrate were 5 – 13-fold higher than previous studies that used hard coal for methanogenesis. Based on these results, and that the development and optimization of the biological oxidation process is currently ongoing, further applications investigated in this study were undertaken using geologically oxidized coal. It was shown using pyrolysis gas chromatography mass spectrometry that the methanogenic system was dependent on the presence of an effective co-substrate supporting the breakdown of the complex organic structures within the oxidized hard coal substrate. Also that the accumulation of aromatic intermediate breakdown compounds predominantly including toluene, furfural, styrene and 2-methoxy vinyl phenol appeared to become inhibitory to both methanogenic and sulfidogenic reactions. This was shown to be a more likely cause of reactor failure rather than substrate exhaustion over time. Evidence of a reductive degradation pathway of the complex organic structures within the oxidized hard coal substrates was shown through the production, accumulation and utilization of volatile fatty acids including acetic, formic, propionic, butyric and valeric acids. Comparative analysis of the volatile fatty acids produced in this system showed that geologically oxidized coal produced 20% more of the volatile fatty acids profiled and double the total concentration compared to the biologically oxidized coal. The use of geologically oxidized hard coal as a functional substrate for biological sulfate reduction was demonstrated in the neutralization of a simulated acid mine drainage wastewater in both batch and continuous process operations. Results showed an increase in pH from pH 4.0 to ~ pH 8.0 with sulfide production rates of ~ 86 mgL-1.day-1 in the batch reactions, while the pH increased to pH 9.0 and sulfide production rates of up to 450 mgL-1.day-1 were measured in the continuous process studies using sand and coal up-flow packed bed reactors. Again, the requirement for an effective co-substrate was demonstrated with lactate shown to function as a true co-substrate in this system. However, a low cost alternative to lactate would need to emerge if the process was to function in large-scale commercial environmental treatment applications. In this regard, the aerobic growth and production of Neosartorya fischeri biomass (0.64 g.biomass.g SOC-1) was demonstrated using oxidized hard coal and glutamate as a co-substrate. Both can be produced from wastes generated on coal mines, with the fungal biomass generated in potentially large volumes. Preliminary demonstration of the use of the fungal biomass as a carbon and electron donor source for biological sulfate reduction was shown and thus that this could serve as an effective substrate for anaerobic environmental treatment processes. Based on these findings, an Integrated Coal Bioprocess model was proposed using oxidized hard coal as a substrate for environmental remediation applications on coal mines. In this approach, potential applications included methane recovery from waste coal, use of waste coal in the treatment of acid mine drainage waste waters and the recovery and use of humic acids in the rehabilitation of open cast mining soils. This study provided a first report demonstrating the use of biologically and geologically oxidized hard coals as bioprocess substrates in environmental bioremediation applications. It also provided an indication that follow-up bioengineering studies to investigate scaled-up applications of these findings would be warranted.
- Full Text:
- Date Issued: 2010
- Authors: Mutambanengwe, Cecil Clifford Zvandada
- Date: 2010
- Subjects: Coal -- Biotechnology Acid mine drainage Coal mines and mining -- Environmental aspects
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3934 , http://hdl.handle.net/10962/d1003993
- Description: The development of coal biotechnology, using hard coal as a substrate, has been impeded by its low reactivity in biological processes. As a result, the more successful application studies have focused on lignitic soft coals. However, new studies have reported using biologically or geologically oxidized hard coal as a functional substrate option for bioprocess applications on a large scale. This study undertook a preliminary investigation into the feasibility of environmental applications of coal biotechnology using oxidized hard coal substrates in both anaerobic and aerobic processes with carbon dioxide, sulfate and oxygen as terminal electron acceptors. A preliminary characterization of the oxidized hard coal substrates was undertaken to determine and predict their viability and behavior as electron donors and carbon sources for environmental bioprocess applications of direct interest to the coal mining industry. Both biologically and geologically oxidized coal substrates showed loss of up to 17% and 52% carbon respectively and incorporation of oxygen ranging from 0.9 – 24%. The latter substrate showed greater loss of carbon and increased oxygenation. The biologically and geologically oxidized hard coal substrates were shown to partition readily into 23% and 32% organic humic acid, a 0.1% fulvic acid fraction and 65% and 59% inorganic and humin fractions respectively. These organic components were shown to be potentially available for biological consumption. In the unmodified hard coal substrate, partitioning was not observed and it did not perform as a functional substrate for any of the bioprocesses investigated. Where carbon dioxide was used as a terminal electron acceptor, methane production ranging from 9 – 26 mg CH4.g substrate-1 was demonstrated from both oxidized coal substrates. Geologically oxidized coal produced 30% more methane than biologically oxidized coal. Methane yields from the geologically oxidized coal in the presence and absence of a co-substrate were 5 – 13-fold higher than previous studies that used hard coal for methanogenesis. Based on these results, and that the development and optimization of the biological oxidation process is currently ongoing, further applications investigated in this study were undertaken using geologically oxidized coal. It was shown using pyrolysis gas chromatography mass spectrometry that the methanogenic system was dependent on the presence of an effective co-substrate supporting the breakdown of the complex organic structures within the oxidized hard coal substrate. Also that the accumulation of aromatic intermediate breakdown compounds predominantly including toluene, furfural, styrene and 2-methoxy vinyl phenol appeared to become inhibitory to both methanogenic and sulfidogenic reactions. This was shown to be a more likely cause of reactor failure rather than substrate exhaustion over time. Evidence of a reductive degradation pathway of the complex organic structures within the oxidized hard coal substrates was shown through the production, accumulation and utilization of volatile fatty acids including acetic, formic, propionic, butyric and valeric acids. Comparative analysis of the volatile fatty acids produced in this system showed that geologically oxidized coal produced 20% more of the volatile fatty acids profiled and double the total concentration compared to the biologically oxidized coal. The use of geologically oxidized hard coal as a functional substrate for biological sulfate reduction was demonstrated in the neutralization of a simulated acid mine drainage wastewater in both batch and continuous process operations. Results showed an increase in pH from pH 4.0 to ~ pH 8.0 with sulfide production rates of ~ 86 mgL-1.day-1 in the batch reactions, while the pH increased to pH 9.0 and sulfide production rates of up to 450 mgL-1.day-1 were measured in the continuous process studies using sand and coal up-flow packed bed reactors. Again, the requirement for an effective co-substrate was demonstrated with lactate shown to function as a true co-substrate in this system. However, a low cost alternative to lactate would need to emerge if the process was to function in large-scale commercial environmental treatment applications. In this regard, the aerobic growth and production of Neosartorya fischeri biomass (0.64 g.biomass.g SOC-1) was demonstrated using oxidized hard coal and glutamate as a co-substrate. Both can be produced from wastes generated on coal mines, with the fungal biomass generated in potentially large volumes. Preliminary demonstration of the use of the fungal biomass as a carbon and electron donor source for biological sulfate reduction was shown and thus that this could serve as an effective substrate for anaerobic environmental treatment processes. Based on these findings, an Integrated Coal Bioprocess model was proposed using oxidized hard coal as a substrate for environmental remediation applications on coal mines. In this approach, potential applications included methane recovery from waste coal, use of waste coal in the treatment of acid mine drainage waste waters and the recovery and use of humic acids in the rehabilitation of open cast mining soils. This study provided a first report demonstrating the use of biologically and geologically oxidized hard coals as bioprocess substrates in environmental bioremediation applications. It also provided an indication that follow-up bioengineering studies to investigate scaled-up applications of these findings would be warranted.
- Full Text:
- Date Issued: 2010
The botanical importance and health of the Bushmans estuary, Eastern Cape, South Africa
- Authors: Jafta, Nolusindiso
- Date: 2010
- Subjects: Estuaries -- South Africa , Bushmans river estuary , Estuarine ecology -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10614 , http://hdl.handle.net/10948/1255 , Estuaries -- South Africa , Bushmans river estuary , Estuarine ecology -- South Africa
- Description: The Bushmans Estuary is one of the few permanently open estuaries in the Eastern Cape that is characterized by large intertidal salt marshes. Freshwater inflow to the estuary has decreased as a result of abstraction by more than 30 weirs and farm dams in the catchment. The mean annual run-off is naturally low (38 x 106 m3 y-1) and thus abstraction and reduction of freshwater inflow to the estuary is expected to cause a number of changes. The aims of this study were to determine the current health/status of the estuary based on the macrophytes and microalgae and identify monitoring indicators for the East London Department of Water Affairs, River Health Programme. Changes in the estuary over time were determined from available historical data which were compared with present data. This analysis showed that under normal average conditions freshwater inflow to the estuary is very low, less that 0.02 m3 s-1 most of the time. Under these conditions the estuary is in a homogenous marine state. Vertical and horizontal salinity gradients only form when high rainfall and run-off occurs (> 5 m3.s-1). Salinity gradients from 30.1 PSU at the mouth to 2.2 PSU in the upper reaches were measured in 2006 after a high flow event. However the estuary quickly reverted back to its homogenous condition within weeks after this flood. This study showed that freshwater inflow increased nutrient input to the estuary. Total oxidised nitrogen (TOxN) and soluble reactive phosphorus (SRP) concentrations were higher in August 2006, after the flood, than during the other low flow sampling sessions. TOxN decreased from a mean concentration of 21.6 μM in 2006 to 1.93 μM in February 2009. SRP decreased from 55.3 μM to 0.2 μM respectively. With the increased nutrient availability, the response in the estuary was an increase in phytoplankton biomass. After the 2006 floods the average water column chlorophyll-a was 9.0 μg l-1, while in the low freshwater inflow years it ranged from 2.1 to 4.8 μg l-1. The composition of the phytoplankton community was always dominated by flagellates and then diatoms, with higher cell numbers in the nutrient-enriched 2006 period. Although the water column nutrient data indicated that the estuary was oligotrophic, benthic microalgal biomass (11.9-16.1 μg.g-1) in the intertidal zone was comparable with nutrient rich estuaries. Benthic species indicative of polluted conditions were found (Nitzschia frustulum, Navicula gregaria, Navicula cryptotenelloides). These benthic species were found at the sites where wastewater / sewage seepage had occurred. Benthic diatom species also indicated freshwater inflow. During the high flow period in 2006 the dominant diatoms were fresh to brackish species that were strongly associated with the high concentrations of TOxN and SRP (Tryblionella constricta, Diploneis smithii, Hippodonta cf. gremainii, and Navicula species). During the freshwater limited period of 2008 and 2009 the benthic diatom species shifted to a group responding to the high salinity, ammonium and silicate concentrations. The species in this group were Nitzschia flexa, Navicula tenneloides, Diploneis elliptica, Amphora subacutiuscula and Nitzschia coarctata. Ordination results showed that the epiphytic diatom species responded to different environmental variables in the different years. Most of the species in 2008/2009 were associated with high salinity, temperature, dissolved oxygen, ammonium and silicate concentrations while the response was towards TOxN and SRP in 2006. The dominant species were Cocconeis placentula v euglyphyta in 2006; Nitzschia frustulum in 2008; and Synedra spp in 2009. The average biomass of the epiphytes was significantly lower in May 2008 than in both August 2006 and February 2009; 88.0 + 17.7 mg.m-2, 1.7 + 0.8 mg.m-2, and 61.8 + 14.4 mg.m-2 respectively. GIS mapping of past and present aerial photographs showed that submerged macrophyte (Zostera capensis) cover in 1966 and 1973 was less than that mapped for 2004. Salt marsh also increased its cover over time, from 86.9 ha in 1966 to 126 ha in 2004, colonizing what were bare sandy areas. Long-term monitoring of the health of the Bushmans Estuary should focus on salinity (as an indicator of inflow or deprivation of freshwater), benthic diatom identification and macrophyte distribution and composition (for the detection of pollution input), and bathymetric surveys (for shallowing of the estuary due to sedimentation).
- Full Text:
- Date Issued: 2010
- Authors: Jafta, Nolusindiso
- Date: 2010
- Subjects: Estuaries -- South Africa , Bushmans river estuary , Estuarine ecology -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10614 , http://hdl.handle.net/10948/1255 , Estuaries -- South Africa , Bushmans river estuary , Estuarine ecology -- South Africa
- Description: The Bushmans Estuary is one of the few permanently open estuaries in the Eastern Cape that is characterized by large intertidal salt marshes. Freshwater inflow to the estuary has decreased as a result of abstraction by more than 30 weirs and farm dams in the catchment. The mean annual run-off is naturally low (38 x 106 m3 y-1) and thus abstraction and reduction of freshwater inflow to the estuary is expected to cause a number of changes. The aims of this study were to determine the current health/status of the estuary based on the macrophytes and microalgae and identify monitoring indicators for the East London Department of Water Affairs, River Health Programme. Changes in the estuary over time were determined from available historical data which were compared with present data. This analysis showed that under normal average conditions freshwater inflow to the estuary is very low, less that 0.02 m3 s-1 most of the time. Under these conditions the estuary is in a homogenous marine state. Vertical and horizontal salinity gradients only form when high rainfall and run-off occurs (> 5 m3.s-1). Salinity gradients from 30.1 PSU at the mouth to 2.2 PSU in the upper reaches were measured in 2006 after a high flow event. However the estuary quickly reverted back to its homogenous condition within weeks after this flood. This study showed that freshwater inflow increased nutrient input to the estuary. Total oxidised nitrogen (TOxN) and soluble reactive phosphorus (SRP) concentrations were higher in August 2006, after the flood, than during the other low flow sampling sessions. TOxN decreased from a mean concentration of 21.6 μM in 2006 to 1.93 μM in February 2009. SRP decreased from 55.3 μM to 0.2 μM respectively. With the increased nutrient availability, the response in the estuary was an increase in phytoplankton biomass. After the 2006 floods the average water column chlorophyll-a was 9.0 μg l-1, while in the low freshwater inflow years it ranged from 2.1 to 4.8 μg l-1. The composition of the phytoplankton community was always dominated by flagellates and then diatoms, with higher cell numbers in the nutrient-enriched 2006 period. Although the water column nutrient data indicated that the estuary was oligotrophic, benthic microalgal biomass (11.9-16.1 μg.g-1) in the intertidal zone was comparable with nutrient rich estuaries. Benthic species indicative of polluted conditions were found (Nitzschia frustulum, Navicula gregaria, Navicula cryptotenelloides). These benthic species were found at the sites where wastewater / sewage seepage had occurred. Benthic diatom species also indicated freshwater inflow. During the high flow period in 2006 the dominant diatoms were fresh to brackish species that were strongly associated with the high concentrations of TOxN and SRP (Tryblionella constricta, Diploneis smithii, Hippodonta cf. gremainii, and Navicula species). During the freshwater limited period of 2008 and 2009 the benthic diatom species shifted to a group responding to the high salinity, ammonium and silicate concentrations. The species in this group were Nitzschia flexa, Navicula tenneloides, Diploneis elliptica, Amphora subacutiuscula and Nitzschia coarctata. Ordination results showed that the epiphytic diatom species responded to different environmental variables in the different years. Most of the species in 2008/2009 were associated with high salinity, temperature, dissolved oxygen, ammonium and silicate concentrations while the response was towards TOxN and SRP in 2006. The dominant species were Cocconeis placentula v euglyphyta in 2006; Nitzschia frustulum in 2008; and Synedra spp in 2009. The average biomass of the epiphytes was significantly lower in May 2008 than in both August 2006 and February 2009; 88.0 + 17.7 mg.m-2, 1.7 + 0.8 mg.m-2, and 61.8 + 14.4 mg.m-2 respectively. GIS mapping of past and present aerial photographs showed that submerged macrophyte (Zostera capensis) cover in 1966 and 1973 was less than that mapped for 2004. Salt marsh also increased its cover over time, from 86.9 ha in 1966 to 126 ha in 2004, colonizing what were bare sandy areas. Long-term monitoring of the health of the Bushmans Estuary should focus on salinity (as an indicator of inflow or deprivation of freshwater), benthic diatom identification and macrophyte distribution and composition (for the detection of pollution input), and bathymetric surveys (for shallowing of the estuary due to sedimentation).
- Full Text:
- Date Issued: 2010
The characterisation of trypanosomal type 1 DnaJ-like proteins
- Authors: Ludewig, Michael Hans
- Date: 2010
- Subjects: Molecular genetics , Molecular chaperones , Protozoa , Heat shock proteins , Trypanosoma
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4126 , http://hdl.handle.net/10962/d1015205
- Description: Trypanosomes are protozoans, of which many are parasitic, and possess complex lifecycles which alternate between mammalian and arthropod hosts. As is the case with most organisms, molecular chaperones and heat shock proteins are encoded within the genomes of these protozoans. These proteins are an integral part of maintaining the structural integrity of proteins during normal and stress conditions. Heat shock protein 40 (Hsp40) is a co-chaperone of heat shock protein 70 (Hsp70) and in some cases can act as a chaperone. These proteins work together to bind non-native polypeptide structures to prevent unfolded protein aggregrate formation in times of stress, translocate proteins across organelle membranes, and transport unsalvageable proteins to proteolytic degradation by the cellular proteasome. Hsp40s are divided into four types based on their domain structure. Analysis of the nuclear genomes of eight trypanosomatid species revealed that less than 10 of the approximate 70 Hsp40 sequences per genome were Type 1 Hsp40s, many of which contained putative orthologues in the other seven trypanosomatid genomes. One of these Type 1 Hsp40s from T b. brucei, Trypanosoma brucei DnaJ 2 (Tbj2), was functionally characterised in T brucei brucei. RNA interference knockdown of expression in T brucei brucei showed that cells deficient in Tbj2 displayed a severe inhibition of the growth of the cell population. The levels of the Tbj2 protein population in T brucei brucei cells increases after exposure to 42°c and the protein was found to have a generalized cytoplasmic subcellular localization at 37°c. These findings provide evidence that Tbj2 is an orthologue of Yeast DnaJ 1 (Y dj l), an essential S. cerevisiae protein. Hsp40s interact with their partner Hsp70s through their J-domain. The amino acids of the J-domain important for a functional interaction with Hsp70 were examined in Trypanosoma cruzi DnaJ 2 (Tcj2) (the orthologue of Tbj2) and T cruzi DnaJ protein 3 (Tcj3) by testing their ability to substitute for Y dj l in Saccharomyces cerevisae and for DnaJ in Escherichia coli. In both systems, the positively charged amino acids of Helix II and III of the J-domain disrupted the functional interaction of these Hsp40s with their partner Hsp70s. Substitutions in Helix I and IV of the J-domains of Tcj2 and Tcj3 produced varied results in the two different systems, possibly suggesting that these helices serve to define with which Hsp70s a given Hsp40 can interact. The inability of an Hsp40 and an Hsp70 to interact functionally does not necessarily mean a total absence of physical interaction between these proteins. The amino acid substitution of the histidine in the HPD motif (H34Q) of the J-domain of Tcj2 and Tcj3 removed the ability of these proteins to interact functionally with S. cerevisiae Hsp70 (Ssal) in vivo. However, preliminary binding studies using the quartz crystal microbalance with dissipation monitoring (QCM-D) show that Tcj2 and Tcj2(H34Q) both physically interact with M sativa Hsp70 in vitro. This study is the first report to provide evidence that certain trypanosoma! Type 1 Hsp40s are essential proteins. Futhermore, the interaction of these Hsp40s with Hsp70 identified important features of the functional interface of this chaperone machinery.
- Full Text:
- Date Issued: 2010
- Authors: Ludewig, Michael Hans
- Date: 2010
- Subjects: Molecular genetics , Molecular chaperones , Protozoa , Heat shock proteins , Trypanosoma
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4126 , http://hdl.handle.net/10962/d1015205
- Description: Trypanosomes are protozoans, of which many are parasitic, and possess complex lifecycles which alternate between mammalian and arthropod hosts. As is the case with most organisms, molecular chaperones and heat shock proteins are encoded within the genomes of these protozoans. These proteins are an integral part of maintaining the structural integrity of proteins during normal and stress conditions. Heat shock protein 40 (Hsp40) is a co-chaperone of heat shock protein 70 (Hsp70) and in some cases can act as a chaperone. These proteins work together to bind non-native polypeptide structures to prevent unfolded protein aggregrate formation in times of stress, translocate proteins across organelle membranes, and transport unsalvageable proteins to proteolytic degradation by the cellular proteasome. Hsp40s are divided into four types based on their domain structure. Analysis of the nuclear genomes of eight trypanosomatid species revealed that less than 10 of the approximate 70 Hsp40 sequences per genome were Type 1 Hsp40s, many of which contained putative orthologues in the other seven trypanosomatid genomes. One of these Type 1 Hsp40s from T b. brucei, Trypanosoma brucei DnaJ 2 (Tbj2), was functionally characterised in T brucei brucei. RNA interference knockdown of expression in T brucei brucei showed that cells deficient in Tbj2 displayed a severe inhibition of the growth of the cell population. The levels of the Tbj2 protein population in T brucei brucei cells increases after exposure to 42°c and the protein was found to have a generalized cytoplasmic subcellular localization at 37°c. These findings provide evidence that Tbj2 is an orthologue of Yeast DnaJ 1 (Y dj l), an essential S. cerevisiae protein. Hsp40s interact with their partner Hsp70s through their J-domain. The amino acids of the J-domain important for a functional interaction with Hsp70 were examined in Trypanosoma cruzi DnaJ 2 (Tcj2) (the orthologue of Tbj2) and T cruzi DnaJ protein 3 (Tcj3) by testing their ability to substitute for Y dj l in Saccharomyces cerevisae and for DnaJ in Escherichia coli. In both systems, the positively charged amino acids of Helix II and III of the J-domain disrupted the functional interaction of these Hsp40s with their partner Hsp70s. Substitutions in Helix I and IV of the J-domains of Tcj2 and Tcj3 produced varied results in the two different systems, possibly suggesting that these helices serve to define with which Hsp70s a given Hsp40 can interact. The inability of an Hsp40 and an Hsp70 to interact functionally does not necessarily mean a total absence of physical interaction between these proteins. The amino acid substitution of the histidine in the HPD motif (H34Q) of the J-domain of Tcj2 and Tcj3 removed the ability of these proteins to interact functionally with S. cerevisiae Hsp70 (Ssal) in vivo. However, preliminary binding studies using the quartz crystal microbalance with dissipation monitoring (QCM-D) show that Tcj2 and Tcj2(H34Q) both physically interact with M sativa Hsp70 in vitro. This study is the first report to provide evidence that certain trypanosoma! Type 1 Hsp40s are essential proteins. Futhermore, the interaction of these Hsp40s with Hsp70 identified important features of the functional interface of this chaperone machinery.
- Full Text:
- Date Issued: 2010
The characteristics and role of informal leaders in work groups : a South African perspective
- Authors: Wienekus, Barend Willem
- Date: 2010
- Subjects: Supervisors, industrial -- South Africa Leadership -- South Africa
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:1166 , http://hdl.handle.net/10962/d1002782
- Description: It has been twenty years since F W De Klerk unbanned the African National Congress. This momentous occasion changed overnight the business landscape in South Africa and the way business were done for many decades. Before and after this crucial moment in South African history, leaders played a significant role in bringing change about as well as managing it. Whether hierarchical or non-hierarchical, leadership manifests itself through all spheres of civilisation. Within any collective, formal as well as informal leadership are always at work and within the environment there always seems to be an individual that appears to hold equal or more influence and sway over the collective. This research investigates the characteristics and role of this individual, the informal leader. In addition, against the melting pot of the diversity of culture, social structures, economics, and demographics in South Africa, the influence of culture on how leadership is being perceived and experienced is also researched. The research is grounded in a post-positivists approach and conducted within a constructivist-interpretative paradigm. A qualitative approach is followed with personal interviews as the method to collect the data from respondents. The interview protocol consists of a combination of questions containing questions of both a quantitative and qualitative nature. Questions of a qualitative nature were open-ended and of an in-depth nature. The research is two pronged. The focus of the research is an Original Equipment Manufacturer (OEM) in the South African Motor Industry and for the primary goal of the research data was collected from employees within work groups of the OEM. The primary research goal investigates the role and characteristics of informal leaders in work groups as seen and experienced by their fellow employees and if there is any congruence with that of the role and characteristics of formal leaders. The study found no fundamental differences between the characteristics and role of formal and informal leaders. The characteristics and role of leaders between different cultures also appear to be the same. For the secondary research goal – determining whether the role and characteristics of informal leaders in work groups could be underpinned in the principles of Ubuntu and if consideration should be given to any cultural differences between leaders and followers by organisational hierarchies – the literature was reviewed in order to reach a conclusion with regards this goal. The literature indicates that culture does affect leadership, especially on how the leadership is executed and experienced in a multicultural society and if ignored, will have a detrimental effect on effective leadership. In order to strive towards achieving maximum productivity, it is imperative that management in South African organisations be aware of the changed dynamic within their organisations as well as on the global stage. The research therefore ends with the practical implications of informal leaders for organisations in South Africa. It is recommended that the importance and contribution of informal leaders within work groups in a multi-culture organisation needs not only to be considered as an element of group leadership, but should be accommodated by the organisation. It is also recommended that organisations recognise the cultural differences between leaders and followers in organisations and the possible consequences if ignored. If the competitive pressures and requirements of globalisation are ignored against the background of Afrocentric expectations and motivational imperatives of the South African workforce, it will result in an ineffective workforce, which will in due course render these organisations uncompetitive and non-sustainable locally and globally.
- Full Text:
- Date Issued: 2010
- Authors: Wienekus, Barend Willem
- Date: 2010
- Subjects: Supervisors, industrial -- South Africa Leadership -- South Africa
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:1166 , http://hdl.handle.net/10962/d1002782
- Description: It has been twenty years since F W De Klerk unbanned the African National Congress. This momentous occasion changed overnight the business landscape in South Africa and the way business were done for many decades. Before and after this crucial moment in South African history, leaders played a significant role in bringing change about as well as managing it. Whether hierarchical or non-hierarchical, leadership manifests itself through all spheres of civilisation. Within any collective, formal as well as informal leadership are always at work and within the environment there always seems to be an individual that appears to hold equal or more influence and sway over the collective. This research investigates the characteristics and role of this individual, the informal leader. In addition, against the melting pot of the diversity of culture, social structures, economics, and demographics in South Africa, the influence of culture on how leadership is being perceived and experienced is also researched. The research is grounded in a post-positivists approach and conducted within a constructivist-interpretative paradigm. A qualitative approach is followed with personal interviews as the method to collect the data from respondents. The interview protocol consists of a combination of questions containing questions of both a quantitative and qualitative nature. Questions of a qualitative nature were open-ended and of an in-depth nature. The research is two pronged. The focus of the research is an Original Equipment Manufacturer (OEM) in the South African Motor Industry and for the primary goal of the research data was collected from employees within work groups of the OEM. The primary research goal investigates the role and characteristics of informal leaders in work groups as seen and experienced by their fellow employees and if there is any congruence with that of the role and characteristics of formal leaders. The study found no fundamental differences between the characteristics and role of formal and informal leaders. The characteristics and role of leaders between different cultures also appear to be the same. For the secondary research goal – determining whether the role and characteristics of informal leaders in work groups could be underpinned in the principles of Ubuntu and if consideration should be given to any cultural differences between leaders and followers by organisational hierarchies – the literature was reviewed in order to reach a conclusion with regards this goal. The literature indicates that culture does affect leadership, especially on how the leadership is executed and experienced in a multicultural society and if ignored, will have a detrimental effect on effective leadership. In order to strive towards achieving maximum productivity, it is imperative that management in South African organisations be aware of the changed dynamic within their organisations as well as on the global stage. The research therefore ends with the practical implications of informal leaders for organisations in South Africa. It is recommended that the importance and contribution of informal leaders within work groups in a multi-culture organisation needs not only to be considered as an element of group leadership, but should be accommodated by the organisation. It is also recommended that organisations recognise the cultural differences between leaders and followers in organisations and the possible consequences if ignored. If the competitive pressures and requirements of globalisation are ignored against the background of Afrocentric expectations and motivational imperatives of the South African workforce, it will result in an ineffective workforce, which will in due course render these organisations uncompetitive and non-sustainable locally and globally.
- Full Text:
- Date Issued: 2010
The child accused in the criminal justice system
- Authors: Brink, Ronelle Bonita
- Date: 2010
- Subjects: Children's rights -- South Africa , Children -- Legal status, laws, etc -- South Africa , Children's rights -- Law and legislation -- South Africa
- Language: English
- Type: Thesis , Masters , LLM
- Identifier: vital:10178 , http://hdl.handle.net/10948/1229 , Children's rights -- South Africa , Children -- Legal status, laws, etc -- South Africa , Children's rights -- Law and legislation -- South Africa
- Description: The high level of crime in South Africa raises the question about the failures of the criminal justice system on the one hand, and South Africa’s social policies on the other. Young people in South Africa can disproportionately be both victims and perpetrators of crime in the Republic of South Africa. The child accused in conflict with the law is dealt with in much the same way as their adult counterparts, as the criminal justice system was designed by adults for adults. South Africa became a signatory to the United Nations Convention on the Rights of the Child 19891(hereinafter referred to as UNCRC) on 16 June 1995. The UNCRC provides a backdrop to section 28 of the Constitution of the Republic of South Africa Act.2 Article 3(1) of the UNCRC provides as follows: “in all actions concerning children, whether undertaken by public or private social welfare institutions, courts of law, administrative authorities or legislative bodies, the best interests of the child shall be primary consideration.” South Africa is therefore according to article 40(3) of the UNCRC obliged to “establish laws, procedures, authorities and institutions specifically applicable to children in conflict with the law”.3 In terms of article 40(1) of the UNCRC “State Parties recognise the right of every child alleged as, accused of, or recognised as having infringed the penal law to be treated in a manner consistent with the promotion of the child’s sense of dignity and worth, which reinforces the child’s respect for the human rights and fundamental freedoms of others and which takes into account the child’s age and the desirability of promoting the child’s reintegration and the child’s assuming a constructive role in society.”4 1 Adopted by the General Assembly resolution 44/25 on 20 November 1989. 2 The Constitution of the Republic of South Africa Act, Act 108 of 1996. Hereinafter referred to as the “Constitution”. 3 South Law Reform Commission Discussion Paper 96. 4 United Nations Convention on the Rights of the Child adopted by the General Assembly resolution 44/25 on 20 November 1989. iv Synopsis 2003 states that “the Ratification of the UNCRC by the South African government in 1995 set the scene for broad-reaching policy and legislative change”.5 The Constitution includes a section protecting children’s rights, which includes the statement that children have the right not to be detained except as a measure of last resort and then for the shortest appropriate period of time, separate from adults and in conditions that take account of his/her age. 6 After being off Parliament’s agenda since 2003, the Child Justice Act7 has recently been reintroduced. The Act aims to ensure consistent, fair and appropriate treatment of the child accused in conflict with the law. The question arises whether the South African Criminal Justice system involving the child accused adequately recognises and protects the interests of the child accused, particularly in view of the present international legal position.
- Full Text:
- Date Issued: 2010
- Authors: Brink, Ronelle Bonita
- Date: 2010
- Subjects: Children's rights -- South Africa , Children -- Legal status, laws, etc -- South Africa , Children's rights -- Law and legislation -- South Africa
- Language: English
- Type: Thesis , Masters , LLM
- Identifier: vital:10178 , http://hdl.handle.net/10948/1229 , Children's rights -- South Africa , Children -- Legal status, laws, etc -- South Africa , Children's rights -- Law and legislation -- South Africa
- Description: The high level of crime in South Africa raises the question about the failures of the criminal justice system on the one hand, and South Africa’s social policies on the other. Young people in South Africa can disproportionately be both victims and perpetrators of crime in the Republic of South Africa. The child accused in conflict with the law is dealt with in much the same way as their adult counterparts, as the criminal justice system was designed by adults for adults. South Africa became a signatory to the United Nations Convention on the Rights of the Child 19891(hereinafter referred to as UNCRC) on 16 June 1995. The UNCRC provides a backdrop to section 28 of the Constitution of the Republic of South Africa Act.2 Article 3(1) of the UNCRC provides as follows: “in all actions concerning children, whether undertaken by public or private social welfare institutions, courts of law, administrative authorities or legislative bodies, the best interests of the child shall be primary consideration.” South Africa is therefore according to article 40(3) of the UNCRC obliged to “establish laws, procedures, authorities and institutions specifically applicable to children in conflict with the law”.3 In terms of article 40(1) of the UNCRC “State Parties recognise the right of every child alleged as, accused of, or recognised as having infringed the penal law to be treated in a manner consistent with the promotion of the child’s sense of dignity and worth, which reinforces the child’s respect for the human rights and fundamental freedoms of others and which takes into account the child’s age and the desirability of promoting the child’s reintegration and the child’s assuming a constructive role in society.”4 1 Adopted by the General Assembly resolution 44/25 on 20 November 1989. 2 The Constitution of the Republic of South Africa Act, Act 108 of 1996. Hereinafter referred to as the “Constitution”. 3 South Law Reform Commission Discussion Paper 96. 4 United Nations Convention on the Rights of the Child adopted by the General Assembly resolution 44/25 on 20 November 1989. iv Synopsis 2003 states that “the Ratification of the UNCRC by the South African government in 1995 set the scene for broad-reaching policy and legislative change”.5 The Constitution includes a section protecting children’s rights, which includes the statement that children have the right not to be detained except as a measure of last resort and then for the shortest appropriate period of time, separate from adults and in conditions that take account of his/her age. 6 After being off Parliament’s agenda since 2003, the Child Justice Act7 has recently been reintroduced. The Act aims to ensure consistent, fair and appropriate treatment of the child accused in conflict with the law. The question arises whether the South African Criminal Justice system involving the child accused adequately recognises and protects the interests of the child accused, particularly in view of the present international legal position.
- Full Text:
- Date Issued: 2010