Synthesis and electrochemistry of octapentylthio phthalocyanine complexes of manganese, titanium and vanadium
- Authors: Mbambisa, Gcineka
- Date: 2009
- Subjects: Electrochemistry , Phthalocyanines -- Synthesis , Manganese , Titanium , Vanadium
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4368 , http://hdl.handle.net/10962/d1005033 , Electrochemistry , Phthalocyanines -- Synthesis , Manganese , Titanium , Vanadium
- Description: Synthesis of new thio derivatised Pcs with manganese, titanium and vanadium as a central metal is reported. The complexes synthesised were characterised using spectroscopic and electrochemical means. The complexes displayed interesting spectroscopic properties with absorption of the Q band being observed in the near infrared region. These complexes have unusual colours for MPc complexes, with purple or red colour being observed in solution. Interesting electrochemical properties were observed, with rare observation of the MnIV/MnIII redox couple. There was observation of oxidation peaks for the pentylthio derivatised Pc with titanium as the central metal; this is unusual since for reported thio derivatives based on TiPc, no oxidation was observed. The vanadium based Pc showed an interesting spectrum for the first ring based reduction. The absorption spectrum obtained for the 1st reduction of the vanadium complex using spectroelectrochemistry would normally indicate a metal based process but comparing with literature it was concluded that it is a ring based reduction process. Generally all the MPc complexes formed a well ordered stable monolayer on the gold electrode. Electrocatalytic studies using L-cysteine revealed that the SAM based on manganese (III) octapentylthio phthalocyanine (AcOMnOPTPc) was the most effective since it catalyses L-cysteine at much lower oxidation potentials and it is also much more stable.
- Full Text:
- Authors: Mbambisa, Gcineka
- Date: 2009
- Subjects: Electrochemistry , Phthalocyanines -- Synthesis , Manganese , Titanium , Vanadium
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4368 , http://hdl.handle.net/10962/d1005033 , Electrochemistry , Phthalocyanines -- Synthesis , Manganese , Titanium , Vanadium
- Description: Synthesis of new thio derivatised Pcs with manganese, titanium and vanadium as a central metal is reported. The complexes synthesised were characterised using spectroscopic and electrochemical means. The complexes displayed interesting spectroscopic properties with absorption of the Q band being observed in the near infrared region. These complexes have unusual colours for MPc complexes, with purple or red colour being observed in solution. Interesting electrochemical properties were observed, with rare observation of the MnIV/MnIII redox couple. There was observation of oxidation peaks for the pentylthio derivatised Pc with titanium as the central metal; this is unusual since for reported thio derivatives based on TiPc, no oxidation was observed. The vanadium based Pc showed an interesting spectrum for the first ring based reduction. The absorption spectrum obtained for the 1st reduction of the vanadium complex using spectroelectrochemistry would normally indicate a metal based process but comparing with literature it was concluded that it is a ring based reduction process. Generally all the MPc complexes formed a well ordered stable monolayer on the gold electrode. Electrocatalytic studies using L-cysteine revealed that the SAM based on manganese (III) octapentylthio phthalocyanine (AcOMnOPTPc) was the most effective since it catalyses L-cysteine at much lower oxidation potentials and it is also much more stable.
- Full Text:
Synthesis and photophysical properties of antimony and lead phthalocyanines
- Modibane, Kwena Desmond, Guest
- Authors: Modibane, Kwena Desmond , Guest
- Date: 2009 , 2009-02-27
- Subjects: Phthalocyanines , Photochemistry , Antimony compounds , Lead compounds
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4370 , http://hdl.handle.net/10962/d1005035 , Phthalocyanines , Photochemistry , Antimony compounds , Lead compounds
- Description: This work hereby presents the synthesis, spectroscopic and photophysical properties of newly synthesized lead (PbPc) and antimony (SbPc) phthalocyanines. The complexes are either unsubstituted or substituted at the peripheral and non-peripheral positions with phenoxy, 4-t-butylphenoxy and 4-benzyloxyphenoxy groups. The photophysical properties of these complexes were studied in dimethylsulfoxide, dimethylformamide, toluene, tetrahydrofuran and chloroform as solvents. The fluorescence spectra for PbPc complexes were different to that of the excitation spectra due to demetallation upon excitation. On the other hand, the excitation spectra of oxidized antimony (Sb(V)Pc) derivatives were found to be similar to absorption spectra. High triplet quantum yields for PbPc and SbPc complexes ranging from 0.70 to 0.86, low triplet lifetimes (20–60 μs in DMSO, while they were <10 μs in the rest of the solvents) and low fluorescence quantum yields were observed and is attributed to the presence of heavy atoms (Pb and Sb ions). The nonlinear optical properties of PbPc complexes were studied in dimethylsulfoxide. The optical limiting threshold intensity (Ilim) for the PbPc derivatives were calculated and ranged from 2.1 to 6.8 W/cm2. The photodegradation studies of the PbPc and SbPc complexes synthesized showed that then are stable.
- Full Text:
- Authors: Modibane, Kwena Desmond , Guest
- Date: 2009 , 2009-02-27
- Subjects: Phthalocyanines , Photochemistry , Antimony compounds , Lead compounds
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4370 , http://hdl.handle.net/10962/d1005035 , Phthalocyanines , Photochemistry , Antimony compounds , Lead compounds
- Description: This work hereby presents the synthesis, spectroscopic and photophysical properties of newly synthesized lead (PbPc) and antimony (SbPc) phthalocyanines. The complexes are either unsubstituted or substituted at the peripheral and non-peripheral positions with phenoxy, 4-t-butylphenoxy and 4-benzyloxyphenoxy groups. The photophysical properties of these complexes were studied in dimethylsulfoxide, dimethylformamide, toluene, tetrahydrofuran and chloroform as solvents. The fluorescence spectra for PbPc complexes were different to that of the excitation spectra due to demetallation upon excitation. On the other hand, the excitation spectra of oxidized antimony (Sb(V)Pc) derivatives were found to be similar to absorption spectra. High triplet quantum yields for PbPc and SbPc complexes ranging from 0.70 to 0.86, low triplet lifetimes (20–60 μs in DMSO, while they were <10 μs in the rest of the solvents) and low fluorescence quantum yields were observed and is attributed to the presence of heavy atoms (Pb and Sb ions). The nonlinear optical properties of PbPc complexes were studied in dimethylsulfoxide. The optical limiting threshold intensity (Ilim) for the PbPc derivatives were calculated and ranged from 2.1 to 6.8 W/cm2. The photodegradation studies of the PbPc and SbPc complexes synthesized showed that then are stable.
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The ambivalent engagement with Christianity in the writing of nineteenth- and early twentieth-century Africans in the Eastern Cape
- Authors: Nxasana, Thulani Litha
- Date: 2009
- Subjects: Authors, African -- South Africa -- Eastern Cape Authors, South African -- 19th century -- Criticism and interpretation Authors, South African -- 20th century -- Criticism and interpretation Soga, Tiyo, 1829-1871 -- Criticism and interpretation Mqhayi, S. E. K. -- Criticism and interpretation Mgqwetho, Nontsizi -- Criticism and interpretation South African literature -- 19th century -- History and criticism South African literature -- 20th century -- History and criticism Christianity and literature Ambivalence in literature
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2195 , http://hdl.handle.net/10962/d1002237
- Description: Until recently much of the literature recording the nineteenth and early twentieth centuries in the Eastern Cape focused purely on frontier conflict and missionary activity, ignoring the evolving culture of the colonized people. But as Somande Fikeni declares, “[i]t is important when celebrating the country’s heritage to look beyond battle sites, monuments and wars and to pay attention to South Africa’s intellectuals and knowledge producers” (quoted in Hollands 4). This is indeed the central purpose of my research. This thesis seeks to examine the influence of Christianity on early South African writing by Africans and the ambivalence with which Christianity is often treated in their work. In South Africa, as elsewhere in Africa, Christianity played a central role in the development of African literature through the influence of mission schools and printing presses. Thus from the outset the development of written literature was inseparable from the spread of Christianity. Nineteenth- and early twentieth-century writing by Africans reflects this: Christian idioms, biblical stories and images colour their work and yet are not employed unthinkingly. Each of the writers whom I will explore has a complex and at times ambivalent relationship with Christianity, and they use religious discourse for a variety of ends, some of them clearly at odds with their origins in the “civilizing mission” of Europe. According to Yunus Momoniat, “Their works . . . are the beginnings of an engagement not only with the world of words on a page, but also with the politics of literacy itself” (1). The subject of this research is three Xhosa writers from the Eastern Cape: the Reverend Tiyo Soga (1829-1871), the renowned novelist and “National Poet” S. E. K. Mqhayi (1875-1945), and the little-known poet Nontsizi Mgqwetho (Dates uknown, writings 1920-1929), who is described by Mbeki as “the most prolific woman Xhosa poet of the twentieth century” (6). The reason for focusing on the Eastern Cape is because the Xhosa “were the first Bantu people to be exposed to Christian proselytising and to receive a literate education” (Gerard 24). As a result much of the early literature in isiXhosa consisted of translations of the Bible and other Christian tracts, and such “improving” texts as Pilgrim’s Progress. In other words, it is in this work that the first roots of the influence of Christianity in southern Africa can be traced.
- Full Text:
- Authors: Nxasana, Thulani Litha
- Date: 2009
- Subjects: Authors, African -- South Africa -- Eastern Cape Authors, South African -- 19th century -- Criticism and interpretation Authors, South African -- 20th century -- Criticism and interpretation Soga, Tiyo, 1829-1871 -- Criticism and interpretation Mqhayi, S. E. K. -- Criticism and interpretation Mgqwetho, Nontsizi -- Criticism and interpretation South African literature -- 19th century -- History and criticism South African literature -- 20th century -- History and criticism Christianity and literature Ambivalence in literature
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2195 , http://hdl.handle.net/10962/d1002237
- Description: Until recently much of the literature recording the nineteenth and early twentieth centuries in the Eastern Cape focused purely on frontier conflict and missionary activity, ignoring the evolving culture of the colonized people. But as Somande Fikeni declares, “[i]t is important when celebrating the country’s heritage to look beyond battle sites, monuments and wars and to pay attention to South Africa’s intellectuals and knowledge producers” (quoted in Hollands 4). This is indeed the central purpose of my research. This thesis seeks to examine the influence of Christianity on early South African writing by Africans and the ambivalence with which Christianity is often treated in their work. In South Africa, as elsewhere in Africa, Christianity played a central role in the development of African literature through the influence of mission schools and printing presses. Thus from the outset the development of written literature was inseparable from the spread of Christianity. Nineteenth- and early twentieth-century writing by Africans reflects this: Christian idioms, biblical stories and images colour their work and yet are not employed unthinkingly. Each of the writers whom I will explore has a complex and at times ambivalent relationship with Christianity, and they use religious discourse for a variety of ends, some of them clearly at odds with their origins in the “civilizing mission” of Europe. According to Yunus Momoniat, “Their works . . . are the beginnings of an engagement not only with the world of words on a page, but also with the politics of literacy itself” (1). The subject of this research is three Xhosa writers from the Eastern Cape: the Reverend Tiyo Soga (1829-1871), the renowned novelist and “National Poet” S. E. K. Mqhayi (1875-1945), and the little-known poet Nontsizi Mgqwetho (Dates uknown, writings 1920-1929), who is described by Mbeki as “the most prolific woman Xhosa poet of the twentieth century” (6). The reason for focusing on the Eastern Cape is because the Xhosa “were the first Bantu people to be exposed to Christian proselytising and to receive a literate education” (Gerard 24). As a result much of the early literature in isiXhosa consisted of translations of the Bible and other Christian tracts, and such “improving” texts as Pilgrim’s Progress. In other words, it is in this work that the first roots of the influence of Christianity in southern Africa can be traced.
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The binding roots of free speech
- Authors: Boughey, Thomas John George
- Date: 2009
- Subjects: Freedom of speech
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2849 , http://hdl.handle.net/10962/d1006255
- Description: This thesis argues that the modern notion of free-speech was born within the Westphalian nation-state. It suggests that the legal rights framework - particular to the Westphalian nationstate - not only legitimizes and legalizes the right to free-speech, but also enables us to invoke legally the necessary limitations that demand the limitation of free-speech in certain contexts. However, such a legal-rights framework is exclusive to the nation-state and cannot be enforced on an international level, outside of the nation-state boundary. With reference to examples on an international level, this thesis demonstrates that calls for the limitation of free-speech are indeed legitimate and necessary but cannot be enforced on an international level for the reasons just mentioned. In order to address this problem, this thesis proposes a framework - based on a Kantian model - that enables us to invoke the limitation of free-speech on an international level without appealing to a legal-rights discourse to do so.
- Full Text:
- Authors: Boughey, Thomas John George
- Date: 2009
- Subjects: Freedom of speech
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2849 , http://hdl.handle.net/10962/d1006255
- Description: This thesis argues that the modern notion of free-speech was born within the Westphalian nation-state. It suggests that the legal rights framework - particular to the Westphalian nationstate - not only legitimizes and legalizes the right to free-speech, but also enables us to invoke legally the necessary limitations that demand the limitation of free-speech in certain contexts. However, such a legal-rights framework is exclusive to the nation-state and cannot be enforced on an international level, outside of the nation-state boundary. With reference to examples on an international level, this thesis demonstrates that calls for the limitation of free-speech are indeed legitimate and necessary but cannot be enforced on an international level for the reasons just mentioned. In order to address this problem, this thesis proposes a framework - based on a Kantian model - that enables us to invoke the limitation of free-speech on an international level without appealing to a legal-rights discourse to do so.
- Full Text:
The conservation and management of freshwater fishes in the Greater Addo Elephant National Park
- Authors: Traas, Graham Ronald Louis
- Date: 2009
- Subjects: Addo Elephant National Park (South Africa) , Freshwater fishes -- South Africa -- Eastern Cape , Fishery conservation -- South Africa -- Eastern Cape , Fishery management -- South Africa -- Eastern Cape , Estuarine fishes -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5247 , http://hdl.handle.net/10962/d1005090 , Addo Elephant National Park (South Africa) , Freshwater fishes -- South Africa -- Eastern Cape , Fishery conservation -- South Africa -- Eastern Cape , Fishery management -- South Africa -- Eastern Cape , Estuarine fishes -- South Africa -- Eastern Cape
- Description: Freshwater fish are the most imperilled vertebrate group with a high projected extinction rate. In general, the world's freshwater ichthyofauna is in a poor state and is threatened by habitat destruction, pollution, the effects of alien species, damming, water extraction and overfishing. Within South Africa, legislation supporting the conservation of aquatic habitats and its associated fauna is strong, but there is a lack of capacity and poor co-ordination between agencies responsible for the conservation and management. The Greater Addo Elephant National Park (GAENP) includes the upper catchments of five of the Sundays River tributaries. Since the optimal method of conserving freshwater aquatic biota is to conserve the headwaters of either the river or its tributaries, there is an opportunity to conserve the native ichthyofauna of the Sundays River system. The principal objective of this thesis was, therefore, to provide information pertinent to the conservation and management of the fishes in the Sundays River system. Sixteen species of freshwater and estuarine fish were sampled, of which eight were alien. Species composition in each of the rivers, with the exception of the Kabouga River, had changed significantly from previous studies. The distribution ranges of several indigenous species had reduced, while those of some alien species was increased. Two species not previously recorded, Labeo capensis and Gambusia affinis, were sampled. Alien species were sampled from all the tributaries. Diversity indices and community assemblage models were identified as approaches for monitoring the ichthyofauna in this species depauperate system. Diversity indices were not recommended for use as a monitoring tool, as they provided insufficient detail on community composition and structure. A modified depletion estimator was applied to multiple pass electrofishing data to determine the effects of various physico-chemical variables on the absolute abundance of Pseudobarbus afer, an endangered species. Pseudobarbus afer density was found to be positively correlated to the presence of boulders. Where P. afer were present, they were abundant. Of the total sampled catch, 21.8% was comprised of alien fishes. Clarias gariepinus was the most successful invader having penetrated all but one of the tributaries. Micropterus salmoides changed the species composition of the Wit River significantly through predation, and is potentially the most dangerous of the alien species in the Sundays River system, capable of extirpating a population of P. afer in as little as three days. Only one man-made barrier to the upstream migration of alien fishes was present on the tributaries, and several addition barriers are required to safeguard the populations of indigenous fish in the headwaters of these tributaries. Several management and conservation tools are presented and discussed, including river rehabilitation, translocation, eradication of alien species, erection of barrier weirs and captive breeding programmes. Public awareness and education is stressed because without support from the communities surrounding the GAENP, management plans for conservation of the indigenous ichthyofauna will, in all likelihood, fail.
- Full Text:
- Authors: Traas, Graham Ronald Louis
- Date: 2009
- Subjects: Addo Elephant National Park (South Africa) , Freshwater fishes -- South Africa -- Eastern Cape , Fishery conservation -- South Africa -- Eastern Cape , Fishery management -- South Africa -- Eastern Cape , Estuarine fishes -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5247 , http://hdl.handle.net/10962/d1005090 , Addo Elephant National Park (South Africa) , Freshwater fishes -- South Africa -- Eastern Cape , Fishery conservation -- South Africa -- Eastern Cape , Fishery management -- South Africa -- Eastern Cape , Estuarine fishes -- South Africa -- Eastern Cape
- Description: Freshwater fish are the most imperilled vertebrate group with a high projected extinction rate. In general, the world's freshwater ichthyofauna is in a poor state and is threatened by habitat destruction, pollution, the effects of alien species, damming, water extraction and overfishing. Within South Africa, legislation supporting the conservation of aquatic habitats and its associated fauna is strong, but there is a lack of capacity and poor co-ordination between agencies responsible for the conservation and management. The Greater Addo Elephant National Park (GAENP) includes the upper catchments of five of the Sundays River tributaries. Since the optimal method of conserving freshwater aquatic biota is to conserve the headwaters of either the river or its tributaries, there is an opportunity to conserve the native ichthyofauna of the Sundays River system. The principal objective of this thesis was, therefore, to provide information pertinent to the conservation and management of the fishes in the Sundays River system. Sixteen species of freshwater and estuarine fish were sampled, of which eight were alien. Species composition in each of the rivers, with the exception of the Kabouga River, had changed significantly from previous studies. The distribution ranges of several indigenous species had reduced, while those of some alien species was increased. Two species not previously recorded, Labeo capensis and Gambusia affinis, were sampled. Alien species were sampled from all the tributaries. Diversity indices and community assemblage models were identified as approaches for monitoring the ichthyofauna in this species depauperate system. Diversity indices were not recommended for use as a monitoring tool, as they provided insufficient detail on community composition and structure. A modified depletion estimator was applied to multiple pass electrofishing data to determine the effects of various physico-chemical variables on the absolute abundance of Pseudobarbus afer, an endangered species. Pseudobarbus afer density was found to be positively correlated to the presence of boulders. Where P. afer were present, they were abundant. Of the total sampled catch, 21.8% was comprised of alien fishes. Clarias gariepinus was the most successful invader having penetrated all but one of the tributaries. Micropterus salmoides changed the species composition of the Wit River significantly through predation, and is potentially the most dangerous of the alien species in the Sundays River system, capable of extirpating a population of P. afer in as little as three days. Only one man-made barrier to the upstream migration of alien fishes was present on the tributaries, and several addition barriers are required to safeguard the populations of indigenous fish in the headwaters of these tributaries. Several management and conservation tools are presented and discussed, including river rehabilitation, translocation, eradication of alien species, erection of barrier weirs and captive breeding programmes. Public awareness and education is stressed because without support from the communities surrounding the GAENP, management plans for conservation of the indigenous ichthyofauna will, in all likelihood, fail.
- Full Text:
The contribution of municipal commonage to local people's livelihoods in small South African towns
- Authors: Davenport, Nicholas Ashbury
- Date: 2009
- Subjects: Land tenure -- South Africa , Land reform -- South Africa , Property -- South Africa , Property rights -- South Africa , Commons -- South Africa -- Eastern Cape , Natural resources, Communal -- Management -- South Africa -- Eastern Cape , Rural development -- South Africa -- Eastern Cape , Households -- Economic aspects -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4749 , http://hdl.handle.net/10962/d1006976 , Land tenure -- South Africa , Land reform -- South Africa , Property -- South Africa , Property rights -- South Africa , Commons -- South Africa -- Eastern Cape , Natural resources, Communal -- Management -- South Africa -- Eastern Cape , Rural development -- South Africa -- Eastern Cape , Households -- Economic aspects -- South Africa -- Eastern Cape
- Description: To redress past discrepancies in land tenure, the ANC government acknowledged that land needs to be made accessible to the previously disadvantaged, announcing that commonage would be a pillar of their land reform programme. Municipal commonage is land granted by the state to municipalities for urban households to use. Presently many urbanites in South Africa seek a livelihood from commonage. However, there has been no livelihood valuation of the contribution commonage makes to previously disadvantaged households. Thus there is a need to calculate the benefits of the commonage programme. Through a two phase approach, this thesis investigated firstly, the proportion of township households which use commonage; and the main characteristics of those households. Secondly, the thesis looks at the extent to which commonage contributes to users' livelihoods and the dominant livelihood strategies pursued by user households. Data was collected for three towns in the Eastern Cape province of South Africa; Bathurst, Fort Beaufort, and Grahamstown. Firstly it was found that between 27-70% of households used commonage, with the largest town having the lowest proportion of users, and vice versa for the smallest town. In terms of household characteristics, each study town was unique. Both Bathurst and Grahamstown user households were poorer than non-using households, however all Fort Beaufort households were considered poor. To assess the benefits of the commonage programme, the marketed and non-marketed consumptive direct-use values of land-based livelihoods on commonage were calculated via the 'own reported values' method. Commonage contributions to total livelihoods ranged between 14-20%. If the contributors from commonage were excluded, over 10% of households in each study town would drop to living below the poverty line. Additionally, commonage was being used productively, with the productivity at each study town being worth over R1 000 per hectare and over R4.7 million per commonage. Finally, a typology of subsistence/survivalist commonage users is presented, with four types being identified. Overall, results suggest that commonage use has increased over the last decade. Moreover, due to food inflation and urbanisation the use of commonage is expected to increase further, highlighting the need for holistic commonage management plans to be created, which should include strategies such as sustainable grazing regimes and natural resource management.
- Full Text:
- Authors: Davenport, Nicholas Ashbury
- Date: 2009
- Subjects: Land tenure -- South Africa , Land reform -- South Africa , Property -- South Africa , Property rights -- South Africa , Commons -- South Africa -- Eastern Cape , Natural resources, Communal -- Management -- South Africa -- Eastern Cape , Rural development -- South Africa -- Eastern Cape , Households -- Economic aspects -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4749 , http://hdl.handle.net/10962/d1006976 , Land tenure -- South Africa , Land reform -- South Africa , Property -- South Africa , Property rights -- South Africa , Commons -- South Africa -- Eastern Cape , Natural resources, Communal -- Management -- South Africa -- Eastern Cape , Rural development -- South Africa -- Eastern Cape , Households -- Economic aspects -- South Africa -- Eastern Cape
- Description: To redress past discrepancies in land tenure, the ANC government acknowledged that land needs to be made accessible to the previously disadvantaged, announcing that commonage would be a pillar of their land reform programme. Municipal commonage is land granted by the state to municipalities for urban households to use. Presently many urbanites in South Africa seek a livelihood from commonage. However, there has been no livelihood valuation of the contribution commonage makes to previously disadvantaged households. Thus there is a need to calculate the benefits of the commonage programme. Through a two phase approach, this thesis investigated firstly, the proportion of township households which use commonage; and the main characteristics of those households. Secondly, the thesis looks at the extent to which commonage contributes to users' livelihoods and the dominant livelihood strategies pursued by user households. Data was collected for three towns in the Eastern Cape province of South Africa; Bathurst, Fort Beaufort, and Grahamstown. Firstly it was found that between 27-70% of households used commonage, with the largest town having the lowest proportion of users, and vice versa for the smallest town. In terms of household characteristics, each study town was unique. Both Bathurst and Grahamstown user households were poorer than non-using households, however all Fort Beaufort households were considered poor. To assess the benefits of the commonage programme, the marketed and non-marketed consumptive direct-use values of land-based livelihoods on commonage were calculated via the 'own reported values' method. Commonage contributions to total livelihoods ranged between 14-20%. If the contributors from commonage were excluded, over 10% of households in each study town would drop to living below the poverty line. Additionally, commonage was being used productively, with the productivity at each study town being worth over R1 000 per hectare and over R4.7 million per commonage. Finally, a typology of subsistence/survivalist commonage users is presented, with four types being identified. Overall, results suggest that commonage use has increased over the last decade. Moreover, due to food inflation and urbanisation the use of commonage is expected to increase further, highlighting the need for holistic commonage management plans to be created, which should include strategies such as sustainable grazing regimes and natural resource management.
- Full Text:
The covariation of South African and foreign equity returns during bull and bear runs : implications for portfolio diversification
- Authors: Mhlanga, Godfrey
- Date: 2009
- Subjects: Stock exchanges -- South Africa , Portfolio management -- South Africa , Investments -- South Africa
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:944 , http://hdl.handle.net/10962/d1002678
- Description: This study examines the pattern of covariation of the industrial index returns of South Africa and foreign industrial sectors. This follows recent increase in national equity correlations and increases in the influence of industry effects in portfolio diversification. The covariation pattern in returns across industries and countries during both bull and bear runs is examined using correlation analysis to determine if there is a difference between the two epochs. The study presents preliminary evidence of the covariation between sectors during a bear and a bull run. Return covariation among sectors is impelled to a greater extent by country-specific factors than by industry-specific factors, implying the segmentation of industrial sectors. Thus, South African investors can in general gain more if a portfolio comprising shares across industries and countries is held, even if these investors buy shares from similar industries.
- Full Text:
- Authors: Mhlanga, Godfrey
- Date: 2009
- Subjects: Stock exchanges -- South Africa , Portfolio management -- South Africa , Investments -- South Africa
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:944 , http://hdl.handle.net/10962/d1002678
- Description: This study examines the pattern of covariation of the industrial index returns of South Africa and foreign industrial sectors. This follows recent increase in national equity correlations and increases in the influence of industry effects in portfolio diversification. The covariation pattern in returns across industries and countries during both bull and bear runs is examined using correlation analysis to determine if there is a difference between the two epochs. The study presents preliminary evidence of the covariation between sectors during a bear and a bull run. Return covariation among sectors is impelled to a greater extent by country-specific factors than by industry-specific factors, implying the segmentation of industrial sectors. Thus, South African investors can in general gain more if a portfolio comprising shares across industries and countries is held, even if these investors buy shares from similar industries.
- Full Text:
The design and synthesis of novel HIV-1 protease inhibitors
- Authors: Tukulula, Matshawandile
- Date: 2009
- Subjects: Protease Inhibitors HIV infections -- Treatment AIDS (Disease) -- Treatment HIV (Viruses) Indolizine -- Derivatives Heterocyclic compounds -- Derivatives Nuclear magnetic resonance Quinoline
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4305 , http://hdl.handle.net/10962/d1004963
- Description: This study has focused on the synthesis of truncated analogues of the hydroxyethylene dipeptide isosteres, such as Ritonavir®, currently in clinical use as HIV-1 protease inhibitors. The reactions of pyridine-2- and quinoline-2-carbaldehydes with methyl acrylate, in the presence of 1,4-diazabicyclo[2.2.2]octane (DABCO) or 3- hydroxyquinuclidine (3-HQ) as nucleophilic catalysts, have afforded a series of Baylis- Hillman adducts, acetylation and cyclisation of which have provided access to a series of indolizine-2-carboxylate esters. The carboxylic acids, obtained by base-catalyzed hydrolysis of these esters, have been coupled with various protected (and unprotected) amino compounds using the peptide coupling agent, 1,1’-carbonyldiimidazole (CDI), to afford a series of indolizine-2-carboxamides as indolizine-based truncated Ritonavir® analogues in quantitative yield. Aza-Michael reactions of pyridine-3-carbaldehydederived Baylis-Hillman adducts with various amino compounds have provided access to a range of pyridine-based products as mixtures of diastereomeric aza-Michael products. The assignment of the relative stereochemistry of the aza-Michael products has been established using 1-D and 2-NOESY experiments and computer modelling techniques. Computer modelling studies have also been conducted on selected aza-Michael products using ACCELRYS Cerius2 software, followed by interactive docking into the HIV-1 protease receptor site, using AUTODOCK 4.0. The docking studies have revealed hydrogen-bonding interactions between the enzyme and the synthetic ligands. Saturation Transfer Difference (STD) NMR experiments have also indicated binding of some of the aza-Michael products to the HIV-1 protease subtype C enzyme, thus indicating their binding and possible inhibitory potential.
- Full Text:
- Authors: Tukulula, Matshawandile
- Date: 2009
- Subjects: Protease Inhibitors HIV infections -- Treatment AIDS (Disease) -- Treatment HIV (Viruses) Indolizine -- Derivatives Heterocyclic compounds -- Derivatives Nuclear magnetic resonance Quinoline
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4305 , http://hdl.handle.net/10962/d1004963
- Description: This study has focused on the synthesis of truncated analogues of the hydroxyethylene dipeptide isosteres, such as Ritonavir®, currently in clinical use as HIV-1 protease inhibitors. The reactions of pyridine-2- and quinoline-2-carbaldehydes with methyl acrylate, in the presence of 1,4-diazabicyclo[2.2.2]octane (DABCO) or 3- hydroxyquinuclidine (3-HQ) as nucleophilic catalysts, have afforded a series of Baylis- Hillman adducts, acetylation and cyclisation of which have provided access to a series of indolizine-2-carboxylate esters. The carboxylic acids, obtained by base-catalyzed hydrolysis of these esters, have been coupled with various protected (and unprotected) amino compounds using the peptide coupling agent, 1,1’-carbonyldiimidazole (CDI), to afford a series of indolizine-2-carboxamides as indolizine-based truncated Ritonavir® analogues in quantitative yield. Aza-Michael reactions of pyridine-3-carbaldehydederived Baylis-Hillman adducts with various amino compounds have provided access to a range of pyridine-based products as mixtures of diastereomeric aza-Michael products. The assignment of the relative stereochemistry of the aza-Michael products has been established using 1-D and 2-NOESY experiments and computer modelling techniques. Computer modelling studies have also been conducted on selected aza-Michael products using ACCELRYS Cerius2 software, followed by interactive docking into the HIV-1 protease receptor site, using AUTODOCK 4.0. The docking studies have revealed hydrogen-bonding interactions between the enzyme and the synthetic ligands. Saturation Transfer Difference (STD) NMR experiments have also indicated binding of some of the aza-Michael products to the HIV-1 protease subtype C enzyme, thus indicating their binding and possible inhibitory potential.
- Full Text:
The development of a practical diet for juvenile dusky kob, Argyrosomus japonicus, for the South African mariculture industry
- Authors: Woolley, Lindsey
- Date: 2009
- Subjects: Fishes -- Nutrition -- Requirements , Fishes -- Food , Fishes -- Growth , Fish culture , Argyrosomus -- Nutrition , Sciaenidae -- Nutrition
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5257 , http://hdl.handle.net/10962/d1005100 , Fishes -- Nutrition -- Requirements , Fishes -- Food , Fishes -- Growth , Fish culture , Argyrosomus -- Nutrition , Sciaenidae -- Nutrition
- Description: The lack of locally manufactured marine finfish diets motivated the current project, which aimed to develop a practical diet specifically formulated for dusky kob. The first growth trial investigated the effect of pellet texture (i.e. hard versus soft pellets) and the inclusion of an additional binder, test treatments were compared to two reference diets. There was no significant difference in weight gain between fish fed the hard or soft pellets (p=0.17), over nine weeks. The fish fed the local trout feed weighed significantly less than those fed the test diets (p=0.003). There was no significant difference in leaching rate amongst treatments (p=0.45). A hard pelleted diet without gelatin is recommended in the commercial culture of dusky kob. Pellets with different physical shapes were tested to determine the effect of shape on settling speeds. A square shaped pellet had a slower sinking rate compared to a round shaped pellet (p<0.0001). Juvenile dusky kob, held in cages, fed the square pellets grew significantly faster than the fish fed the round pellet, with a mean weight gain of 16.81 ± 0.45 g (p=0.018). A growth trial was used to optimize the protein to energy (PE) ratio by adjusting dietary protein and lipid levels. Fish fed the diets with high levels of protein (46 % protein) achieved the better growth rates (125 % weight gain) compared to the lower protein diets (92 % weight gain) (p<0.0001). There was no significant difference in total ammonia production (TAN) level for the 46 and 42 % protein diets (p=0.68). The overall performance of the prototype diet was investigated in a closed recirculating system. Growth and FCR of the fish fed the prototype diet was on a par to those fed the commercially available diet currently used in the local farming industry. There was no significant difference in the blood chemistry for fish held at increased stocking densities. The prototype diet is suitable for use in recirculating systems, as there were no negative effects on water quality parameters. This study has laid a foundation for the manufacture of a practical commercial dusky kob diet in South Africa.
- Full Text:
- Authors: Woolley, Lindsey
- Date: 2009
- Subjects: Fishes -- Nutrition -- Requirements , Fishes -- Food , Fishes -- Growth , Fish culture , Argyrosomus -- Nutrition , Sciaenidae -- Nutrition
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5257 , http://hdl.handle.net/10962/d1005100 , Fishes -- Nutrition -- Requirements , Fishes -- Food , Fishes -- Growth , Fish culture , Argyrosomus -- Nutrition , Sciaenidae -- Nutrition
- Description: The lack of locally manufactured marine finfish diets motivated the current project, which aimed to develop a practical diet specifically formulated for dusky kob. The first growth trial investigated the effect of pellet texture (i.e. hard versus soft pellets) and the inclusion of an additional binder, test treatments were compared to two reference diets. There was no significant difference in weight gain between fish fed the hard or soft pellets (p=0.17), over nine weeks. The fish fed the local trout feed weighed significantly less than those fed the test diets (p=0.003). There was no significant difference in leaching rate amongst treatments (p=0.45). A hard pelleted diet without gelatin is recommended in the commercial culture of dusky kob. Pellets with different physical shapes were tested to determine the effect of shape on settling speeds. A square shaped pellet had a slower sinking rate compared to a round shaped pellet (p<0.0001). Juvenile dusky kob, held in cages, fed the square pellets grew significantly faster than the fish fed the round pellet, with a mean weight gain of 16.81 ± 0.45 g (p=0.018). A growth trial was used to optimize the protein to energy (PE) ratio by adjusting dietary protein and lipid levels. Fish fed the diets with high levels of protein (46 % protein) achieved the better growth rates (125 % weight gain) compared to the lower protein diets (92 % weight gain) (p<0.0001). There was no significant difference in total ammonia production (TAN) level for the 46 and 42 % protein diets (p=0.68). The overall performance of the prototype diet was investigated in a closed recirculating system. Growth and FCR of the fish fed the prototype diet was on a par to those fed the commercially available diet currently used in the local farming industry. There was no significant difference in the blood chemistry for fish held at increased stocking densities. The prototype diet is suitable for use in recirculating systems, as there were no negative effects on water quality parameters. This study has laid a foundation for the manufacture of a practical commercial dusky kob diet in South Africa.
- Full Text:
The development of sustainability criteria to facilitate the selection of sanitation technologies within the Buffalo City Municipality (Eastern Cape Province, South Africa)
- Authors: Hoossein, Shafick
- Date: 2009
- Subjects: Sanitation -- South Africa -- Buffalo City Sustainable development -- South Africa -- Buffalo City Water -- Purification -- South Africa -- Buffalo City Sewage disposal -- South Africa -- Buffalo City Water quality -- South Africa -- Buffalo City Environmental health -- South Africa -- Buffalo City Environmental management -- South Africa -- Buffalo City
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:32275 , http://hdl.handle.net/10962/d1004595
- Description: Two and a half billion people mostly in sub-Saharan Africa and southern Asia remain without improved sanitation facilities despite the Millennium Development Goal 7's target to halve this number by 2015. While it might be tempting for developing countries such as South Africa to implement the cheapest and most rapidly constructed sanitation services simply to meet the desired target, this could have significant negative implications on human health and the environment over the long-term. As a result, there is a need to ensure that the most appropriate sustainable sanitation technologies are selected during the planning stage. The purpose of this research was therefore to document the development and pilot application of a flexible context-specific decision-support tool for sustainable sanitation technology selection within Buffalo City Municipality (BCM) in the Eastern Cape Province of South Africa. The first step in the development process was to ascertain the current status of sanitation within the municipality, with a specific focus on the main challenges related to the provision, maintenance and performance of these technologies. Thereafter, a participatory approach was employed involving BCM stakeholders to develop a series of sustainability criteria and indicators that took into consideration economic, social, environmental and technical concerns as well as legal requirements. The development process resulted in a list of 38 BCM sustainable sanitation selection criteria that were applied in a pilot study involving rural, urban and peri-urban communities within BCM. Certain criteria related to topographical features and the availability of piped water and land were considered useful for 'coarse screening' while others were applied during 'fine screening'. In order to enhance the context specificity of criteria, each was weighted, through consultation with key BCM stakeholders. This research confirmed that the sanitation situation in BCM was poor and preliminary evidence indicated that sanitation systems were negatively impacting on the quality of water resources within BCM justifying the need for a sustainable sanitation decision support tool. Based on the pilot application of the BCM Sustainability Selection Criteria List, the urine diversion technology was considered the most sustainable technology option in each study site. There were however, certain social criteria that received relatively low sustainability scores and these would need to be addressed prior to the approval of this technology for implementation. The approach adopted in this thesis was considered highly context-specific yet flexible and appropriate for adoption not only by BCM but other municipalities on a range of spatial scales.
- Full Text:
- Authors: Hoossein, Shafick
- Date: 2009
- Subjects: Sanitation -- South Africa -- Buffalo City Sustainable development -- South Africa -- Buffalo City Water -- Purification -- South Africa -- Buffalo City Sewage disposal -- South Africa -- Buffalo City Water quality -- South Africa -- Buffalo City Environmental health -- South Africa -- Buffalo City Environmental management -- South Africa -- Buffalo City
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:32275 , http://hdl.handle.net/10962/d1004595
- Description: Two and a half billion people mostly in sub-Saharan Africa and southern Asia remain without improved sanitation facilities despite the Millennium Development Goal 7's target to halve this number by 2015. While it might be tempting for developing countries such as South Africa to implement the cheapest and most rapidly constructed sanitation services simply to meet the desired target, this could have significant negative implications on human health and the environment over the long-term. As a result, there is a need to ensure that the most appropriate sustainable sanitation technologies are selected during the planning stage. The purpose of this research was therefore to document the development and pilot application of a flexible context-specific decision-support tool for sustainable sanitation technology selection within Buffalo City Municipality (BCM) in the Eastern Cape Province of South Africa. The first step in the development process was to ascertain the current status of sanitation within the municipality, with a specific focus on the main challenges related to the provision, maintenance and performance of these technologies. Thereafter, a participatory approach was employed involving BCM stakeholders to develop a series of sustainability criteria and indicators that took into consideration economic, social, environmental and technical concerns as well as legal requirements. The development process resulted in a list of 38 BCM sustainable sanitation selection criteria that were applied in a pilot study involving rural, urban and peri-urban communities within BCM. Certain criteria related to topographical features and the availability of piped water and land were considered useful for 'coarse screening' while others were applied during 'fine screening'. In order to enhance the context specificity of criteria, each was weighted, through consultation with key BCM stakeholders. This research confirmed that the sanitation situation in BCM was poor and preliminary evidence indicated that sanitation systems were negatively impacting on the quality of water resources within BCM justifying the need for a sustainable sanitation decision support tool. Based on the pilot application of the BCM Sustainability Selection Criteria List, the urine diversion technology was considered the most sustainable technology option in each study site. There were however, certain social criteria that received relatively low sustainability scores and these would need to be addressed prior to the approval of this technology for implementation. The approach adopted in this thesis was considered highly context-specific yet flexible and appropriate for adoption not only by BCM but other municipalities on a range of spatial scales.
- Full Text:
The development of the stock market and its effect on economic growth: the case of SADC
- Authors: Elliott, Kevin Andrew
- Date: 2009
- Subjects: Stocks -- Africa, Southern , Stock exchanges -- Africa, Southern , Economic development -- Africa, Southern , Stocks -- Economic aspects -- Africa, Southern
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:967 , http://hdl.handle.net/10962/d1002701 , Stocks -- Africa, Southern , Stock exchanges -- Africa, Southern , Economic development -- Africa, Southern , Stocks -- Economic aspects -- Africa, Southern
- Description: Using a pooled panel data set from nine developing countries within the SADC region from 1992 to 2004, this paper empirically examines; firstly, the relationship between stock market development and long-term economic growth, and secondly, the macroeconomic determinants of stock market development, particularly market capitalisation as a percentage of GDP. The results suggest that there is a strong link between stock market development and economic growth, particularly through the liquidity provided by the market. The evidence obtained lends support to the view that a well-developed and functioning stock market can boost economic growth by enhancing faster capital accumulation and allowing for better resource allocation, particularly in developing countries. In terms of the macroeconomic determinants of stock market development, the results support those of Garcia and Liu (1999), in that we found the indicators of financial intermediary development, the value of shares traded as a percentage of GDP and the macroeconomic instability variable to be important determinants of stock market development.
- Full Text:
- Authors: Elliott, Kevin Andrew
- Date: 2009
- Subjects: Stocks -- Africa, Southern , Stock exchanges -- Africa, Southern , Economic development -- Africa, Southern , Stocks -- Economic aspects -- Africa, Southern
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:967 , http://hdl.handle.net/10962/d1002701 , Stocks -- Africa, Southern , Stock exchanges -- Africa, Southern , Economic development -- Africa, Southern , Stocks -- Economic aspects -- Africa, Southern
- Description: Using a pooled panel data set from nine developing countries within the SADC region from 1992 to 2004, this paper empirically examines; firstly, the relationship between stock market development and long-term economic growth, and secondly, the macroeconomic determinants of stock market development, particularly market capitalisation as a percentage of GDP. The results suggest that there is a strong link between stock market development and economic growth, particularly through the liquidity provided by the market. The evidence obtained lends support to the view that a well-developed and functioning stock market can boost economic growth by enhancing faster capital accumulation and allowing for better resource allocation, particularly in developing countries. In terms of the macroeconomic determinants of stock market development, the results support those of Garcia and Liu (1999), in that we found the indicators of financial intermediary development, the value of shares traded as a percentage of GDP and the macroeconomic instability variable to be important determinants of stock market development.
- Full Text:
The economic potential of small towns in the Eastern Cape Midlands
- Authors: Reynolds, Kian Andrew
- Date: 2009 , 2013-07-15
- Subjects: Small cities -- South Africa -- Eastern Cape Economic geography -- South Africa -- Eastern Cape Economic development -- South Africa -- Eastern Cape Rural development -- South Africa -- Eastern Cape Local government -- South Africa -- Eastern Cape Agriculture -- Economic aspects -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:1057 , http://hdl.handle.net/10962/d1007492
- Description: Small town economic decline has been experienced in many countries across the globe and can be explained through Geographical Economics, particularly the New Economic Geography, which suggests that agglomeration occurs as a natural outcome of high transportation and transactional costs. Yet despite the economic rationale behind their decline it is not an economic inevitability and there is evidence of towns in the United States, New Zealand and Canada that have reversed their economic fortunes. [n South Africa approximately 5 million people live in the 500 small towns and many more live in their rural hinterlands where povelty levels are extremely high within a national context. Within this context the thesis examines the current economic status and potential growth prospects of small towns in the Eastern Cape Midlands in South Africa in order to identify critical growth dri vers within small town economies. Five small towns were selected for the study via means of a purposive sample and were subjected to two regional modelling techniques, namely Shift-Share Analysis and Economic Base Theory to determine their current economic trends and past growth patterns, while a Social Accounting Matrix was utilised to identify important sectoral linkages, potential avenues for growth and evident leakages within small town economies. The sampled towns experienced negative economic growth trends between 1996 and 200 I, the primary loss in employment being accounted for by regional economic changes as opposed to national or industrial trends. The decline was more severely felt in primary/industrial sectors of the economy; evidence was found that manufacturing activities declined in all of the centres, despite the industry growing nationally. The Social Accounting Matrix highlighted strong links between the agricultural and services sectors within the national economy. Thus, considering that agriculture was identified as the primary economic driver within the region and the services sector the largest employer in all of the towns it is evident that the economic potential of the towns is to a certain extent linked to the success of agriculture in their hinterlands. Seven growth drivers, namely size, local economic development, existing markets, existing industries, infrastructure, municipal leadership and local entrepreneurs and were linked via means of a scoring framework to the sampled towns' economic potential. Whilst the results of actually determining a towns economic potential are not definitive the study does provide useful insights about the impact and potential role played by these drivers. Linked to this scoring framework and to Cook's (1971) hierarchy of places in the Eastern Cape Midlands four categories of towns were identified in the commercial falming areas and recommendations were made about appropriate developmental interventions at a municipal level, such as the need to retain local entrepreneurs and to invest in social amenities. Considering the evident need for development in rural areas the study provides critical insights into how to prioritise development strategies within small rural towns in commercial farming areas. In addition it would enable municipalities to critically reflect on their municipal Local Economic Development strategies and the relevance within the context of small towns. , KMBT_363 , Adobe Acrobat 9.54 Paper Capture Plug-in
- Full Text:
- Authors: Reynolds, Kian Andrew
- Date: 2009 , 2013-07-15
- Subjects: Small cities -- South Africa -- Eastern Cape Economic geography -- South Africa -- Eastern Cape Economic development -- South Africa -- Eastern Cape Rural development -- South Africa -- Eastern Cape Local government -- South Africa -- Eastern Cape Agriculture -- Economic aspects -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:1057 , http://hdl.handle.net/10962/d1007492
- Description: Small town economic decline has been experienced in many countries across the globe and can be explained through Geographical Economics, particularly the New Economic Geography, which suggests that agglomeration occurs as a natural outcome of high transportation and transactional costs. Yet despite the economic rationale behind their decline it is not an economic inevitability and there is evidence of towns in the United States, New Zealand and Canada that have reversed their economic fortunes. [n South Africa approximately 5 million people live in the 500 small towns and many more live in their rural hinterlands where povelty levels are extremely high within a national context. Within this context the thesis examines the current economic status and potential growth prospects of small towns in the Eastern Cape Midlands in South Africa in order to identify critical growth dri vers within small town economies. Five small towns were selected for the study via means of a purposive sample and were subjected to two regional modelling techniques, namely Shift-Share Analysis and Economic Base Theory to determine their current economic trends and past growth patterns, while a Social Accounting Matrix was utilised to identify important sectoral linkages, potential avenues for growth and evident leakages within small town economies. The sampled towns experienced negative economic growth trends between 1996 and 200 I, the primary loss in employment being accounted for by regional economic changes as opposed to national or industrial trends. The decline was more severely felt in primary/industrial sectors of the economy; evidence was found that manufacturing activities declined in all of the centres, despite the industry growing nationally. The Social Accounting Matrix highlighted strong links between the agricultural and services sectors within the national economy. Thus, considering that agriculture was identified as the primary economic driver within the region and the services sector the largest employer in all of the towns it is evident that the economic potential of the towns is to a certain extent linked to the success of agriculture in their hinterlands. Seven growth drivers, namely size, local economic development, existing markets, existing industries, infrastructure, municipal leadership and local entrepreneurs and were linked via means of a scoring framework to the sampled towns' economic potential. Whilst the results of actually determining a towns economic potential are not definitive the study does provide useful insights about the impact and potential role played by these drivers. Linked to this scoring framework and to Cook's (1971) hierarchy of places in the Eastern Cape Midlands four categories of towns were identified in the commercial falming areas and recommendations were made about appropriate developmental interventions at a municipal level, such as the need to retain local entrepreneurs and to invest in social amenities. Considering the evident need for development in rural areas the study provides critical insights into how to prioritise development strategies within small rural towns in commercial farming areas. In addition it would enable municipalities to critically reflect on their municipal Local Economic Development strategies and the relevance within the context of small towns. , KMBT_363 , Adobe Acrobat 9.54 Paper Capture Plug-in
- Full Text:
The effect of load and technique on biomechanical and perceptual responses during dynamic pushing and pulling
- Authors: Desai, Sheena Dhiksha
- Date: 2009
- Subjects: Work -- Physiological aspects , Biomechanics , Human engineering , Lifting and carrying
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5109 , http://hdl.handle.net/10962/d1005187 , Work -- Physiological aspects , Biomechanics , Human engineering , Lifting and carrying
- Description: Changes in the industrial job profile, from lifting and lowering to repetitive dynamic pushing and pulling have been facilitated through the use of manual vehicles, aimed at minimising the workload. Yet, the demands of pushing and pulling have not been well documented. Using measures of the horizontal component of the hand forces, spinal kinematics, muscle activity at various sites on the upper body and body discomfort ratings, this study aimed at quantifying the biomechanical and perceptual demands of various dynamic push/pull techniques. 36 healthy male participants performed two-handed forward pushing, two-handed backward pulling and one-handed forward pulling, employing an industrial pallet jack supporting two loads of 250kg or 500kg. While no single technique was definitively identified as preferable regarding hand forces, pushing at 500kg elicited higher initial and sustained forces (p<0.05) than one- and two-handed pulling respectively. Increments in load mass from 250kg to 500kg resulted in significant differences in the initial, sustained and ending forces. With regard to spinal kinematics in the sagittal plane, two-handed pulling elicited the highest trunk flexion, and may therefore expose individuals to prolonged forward bending. Generally this technique was found to evoke the highest sagittal responses. Spinal kinematic measures in the lateral and transverse planes suggested that one-handed pulling was accompanied by the highest measures, and hence the greatest risk of developing lower back disorders related to this plane. Although various combinations of muscles were active during each technique, one-handed pulling and pushing, most often induced the highest muscle activation levels and two-handed pulling, the lowest. While erector spinae evidenced no significant differences between techniques at each load or between loads for the same technique, activation levels were high under all conditions. Perceptual ratings of body discomfort revealed that not only is the upper body susceptible to injuries during pushing and pulling, but also that the lower extremities may have a considerable role to play in these tasks, with the calves being a particular area of concern. Findings concluded that symmetrical pushing and pulling tasks are preferable.
- Full Text:
- Authors: Desai, Sheena Dhiksha
- Date: 2009
- Subjects: Work -- Physiological aspects , Biomechanics , Human engineering , Lifting and carrying
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5109 , http://hdl.handle.net/10962/d1005187 , Work -- Physiological aspects , Biomechanics , Human engineering , Lifting and carrying
- Description: Changes in the industrial job profile, from lifting and lowering to repetitive dynamic pushing and pulling have been facilitated through the use of manual vehicles, aimed at minimising the workload. Yet, the demands of pushing and pulling have not been well documented. Using measures of the horizontal component of the hand forces, spinal kinematics, muscle activity at various sites on the upper body and body discomfort ratings, this study aimed at quantifying the biomechanical and perceptual demands of various dynamic push/pull techniques. 36 healthy male participants performed two-handed forward pushing, two-handed backward pulling and one-handed forward pulling, employing an industrial pallet jack supporting two loads of 250kg or 500kg. While no single technique was definitively identified as preferable regarding hand forces, pushing at 500kg elicited higher initial and sustained forces (p<0.05) than one- and two-handed pulling respectively. Increments in load mass from 250kg to 500kg resulted in significant differences in the initial, sustained and ending forces. With regard to spinal kinematics in the sagittal plane, two-handed pulling elicited the highest trunk flexion, and may therefore expose individuals to prolonged forward bending. Generally this technique was found to evoke the highest sagittal responses. Spinal kinematic measures in the lateral and transverse planes suggested that one-handed pulling was accompanied by the highest measures, and hence the greatest risk of developing lower back disorders related to this plane. Although various combinations of muscles were active during each technique, one-handed pulling and pushing, most often induced the highest muscle activation levels and two-handed pulling, the lowest. While erector spinae evidenced no significant differences between techniques at each load or between loads for the same technique, activation levels were high under all conditions. Perceptual ratings of body discomfort revealed that not only is the upper body susceptible to injuries during pushing and pulling, but also that the lower extremities may have a considerable role to play in these tasks, with the calves being a particular area of concern. Findings concluded that symmetrical pushing and pulling tasks are preferable.
- Full Text:
The effect of load and technique on biomechanical and psychophysical responses to level dynamic pushing and pulling
- Authors: Bennett, Anthea Iona
- Date: 2009
- Subjects: Work -- Physiological aspects , Human engineering -- Case studies , Lifting and carrying -- Case studies , Biomechanics -- Case studies , Musculoskeletal system -- Wounds and injuries
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5110 , http://hdl.handle.net/10962/d1005188 , Work -- Physiological aspects , Human engineering -- Case studies , Lifting and carrying -- Case studies , Biomechanics -- Case studies , Musculoskeletal system -- Wounds and injuries
- Description: Pushing and pulling research has yet to fully elucidate the demands placed on manual workers despite established epidemiological links to musculoskeletal disorders. The current study therefore aimed to quantify biomechanical and perceptual responses of male operators to dynamic pushing and pulling tasks. Three common push/pull techniques (pushing, one handed and two handed pulling) were performed at loads of 250kg and 500kg using an industrial pallet jack in a laboratory environment. Thirty six healthy male subjects (age: 21 ±2 years, stature: 1791 ±43 mm and body mass: 77 ±10 kg) were required to perform six loaded experimental and two unloaded control conditions. Hand force exertion, muscle activity and gait pattern responses were collected during 10m push/pull trials on a coefficient controlled walkway; body discomfort was assessed on completion of the condition. Horizontal hand force responses were significantly (p<0.05) affected by load, with a linear relationship existing between the two. This relationship is determined by specific environmental and trolley factors and is context specific, depending on factors such as trolley maintenance and type of flooring. Hand force exertion responses were tenuously affected by technique at higher loads in the initial and sustained phases, with pushing inducing the greatest hand forces. Comparison of the motion phases revealed significant differences between all three phases, with the initial phase evidencing the greatest hand forces. Muscle activity responses demonstrated that unloaded backward walking evoked significantly higher muscle activation than did unloaded forward walking whilst increased muscular activity during load movement compared to unloaded walking was observed. However increasing load from 250kg to 500kg did not significantly impact the majority of muscle activity responses. When considering technique effects on muscle activity, of the significant differences found, all indicated that pushing imposed the least demand on the musculoskeletal system. Gait pattern responses were not significantly affected by load/technique combinations and were similar to those elicited during normal, unloaded walking. Perceptually, increased load led to increased perception of discomfort while pushing resulted in the least discomfort at both loads. From these psychophysical responses, the calves, shoulders and biceps were identified as areas of potential musculoskeletal injury, particularly during one and two handed pulling. Pushing elicited the highest hand forces and the lowest muscle activity responses in the majority of the conditions whilst psychophysical responses identified this technique as most satisfactory. Current results advocate the use of pushing when moving a load using a wheeled device. Suitability of one and two handed pulling remains contradictory, however results suggest that one handed pulling be employed at lower loads and two handed pulling at higher loads.
- Full Text:
- Authors: Bennett, Anthea Iona
- Date: 2009
- Subjects: Work -- Physiological aspects , Human engineering -- Case studies , Lifting and carrying -- Case studies , Biomechanics -- Case studies , Musculoskeletal system -- Wounds and injuries
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5110 , http://hdl.handle.net/10962/d1005188 , Work -- Physiological aspects , Human engineering -- Case studies , Lifting and carrying -- Case studies , Biomechanics -- Case studies , Musculoskeletal system -- Wounds and injuries
- Description: Pushing and pulling research has yet to fully elucidate the demands placed on manual workers despite established epidemiological links to musculoskeletal disorders. The current study therefore aimed to quantify biomechanical and perceptual responses of male operators to dynamic pushing and pulling tasks. Three common push/pull techniques (pushing, one handed and two handed pulling) were performed at loads of 250kg and 500kg using an industrial pallet jack in a laboratory environment. Thirty six healthy male subjects (age: 21 ±2 years, stature: 1791 ±43 mm and body mass: 77 ±10 kg) were required to perform six loaded experimental and two unloaded control conditions. Hand force exertion, muscle activity and gait pattern responses were collected during 10m push/pull trials on a coefficient controlled walkway; body discomfort was assessed on completion of the condition. Horizontal hand force responses were significantly (p<0.05) affected by load, with a linear relationship existing between the two. This relationship is determined by specific environmental and trolley factors and is context specific, depending on factors such as trolley maintenance and type of flooring. Hand force exertion responses were tenuously affected by technique at higher loads in the initial and sustained phases, with pushing inducing the greatest hand forces. Comparison of the motion phases revealed significant differences between all three phases, with the initial phase evidencing the greatest hand forces. Muscle activity responses demonstrated that unloaded backward walking evoked significantly higher muscle activation than did unloaded forward walking whilst increased muscular activity during load movement compared to unloaded walking was observed. However increasing load from 250kg to 500kg did not significantly impact the majority of muscle activity responses. When considering technique effects on muscle activity, of the significant differences found, all indicated that pushing imposed the least demand on the musculoskeletal system. Gait pattern responses were not significantly affected by load/technique combinations and were similar to those elicited during normal, unloaded walking. Perceptually, increased load led to increased perception of discomfort while pushing resulted in the least discomfort at both loads. From these psychophysical responses, the calves, shoulders and biceps were identified as areas of potential musculoskeletal injury, particularly during one and two handed pulling. Pushing elicited the highest hand forces and the lowest muscle activity responses in the majority of the conditions whilst psychophysical responses identified this technique as most satisfactory. Current results advocate the use of pushing when moving a load using a wheeled device. Suitability of one and two handed pulling remains contradictory, however results suggest that one handed pulling be employed at lower loads and two handed pulling at higher loads.
- Full Text:
The effect of progressive resistance training on the blood lipid profile in post-menopausal women
- Authors: Viljoen, Janet Erica
- Date: 2009
- Subjects: Weight training for women -- Physiological aspects , Weight training -- Physiological aspects , Exercise for women -- Physiological aspects , Physical fitness for women -- Physiological aspects , Energy metabolism , Middle aged women -- Health and hygiene
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5113 , http://hdl.handle.net/10962/d1005191 , Weight training for women -- Physiological aspects , Weight training -- Physiological aspects , Exercise for women -- Physiological aspects , Physical fitness for women -- Physiological aspects , Energy metabolism , Middle aged women -- Health and hygiene
- Description: The main purpose of this study was to assess the effect of progressive resistance training on the blood lipid profile in post-menopausal women. Thirty-four female subjects aged 50 to 75 years were selected from the population of Grahamstown, South Africa. All participants were previously sedentary and possessed at least one lipid profile abnormality but were otherwise healthy. Pre-tests included a sub-maximal stress Electrocardiogram, measures of stature, mass, central and limb girths as well as an oral glucose tolerance test (OGTT) and a total blood lipid profile. Participants took part in a 24-week progressive resistance training programme, consisting of three supervised sessions per week, each lasting 45 minutes and were not permitted to lose more than 10% of initial body mass during the 24-week study. All pre-test measures, excluding the stress ECG and the OGTT, were repeated every four weeks for the duration of the study. Results were that body mass, body mass index and waist-to-hip ratio did not change. Girth measures at mid-humerus, chest, waist, hip, mid-quadricep and mid-gastrocnemius all decreased significantly (p=0.05). LDL-cholesterol increased significantly over the course of 24 weeks (3.61mmol.L-1 to 4.07mmol.L-1) as did total cholesterol (5.81mmol.L-1 to 6.24mmol.L-1). Triglyceride concentration remained unchanged and HDL-cholesterol decreased significantly between the pre-test measure (1.55mmol.L-1) and the measure after six months (1.42mmol.L-1). It can be concluded that the blood lipid profile in a sample of post-menopausal women was not positively affected by a progressive resistance training programme over a 24 week period. , Maiden name: Kelly, Janet Erica
- Full Text:
- Authors: Viljoen, Janet Erica
- Date: 2009
- Subjects: Weight training for women -- Physiological aspects , Weight training -- Physiological aspects , Exercise for women -- Physiological aspects , Physical fitness for women -- Physiological aspects , Energy metabolism , Middle aged women -- Health and hygiene
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5113 , http://hdl.handle.net/10962/d1005191 , Weight training for women -- Physiological aspects , Weight training -- Physiological aspects , Exercise for women -- Physiological aspects , Physical fitness for women -- Physiological aspects , Energy metabolism , Middle aged women -- Health and hygiene
- Description: The main purpose of this study was to assess the effect of progressive resistance training on the blood lipid profile in post-menopausal women. Thirty-four female subjects aged 50 to 75 years were selected from the population of Grahamstown, South Africa. All participants were previously sedentary and possessed at least one lipid profile abnormality but were otherwise healthy. Pre-tests included a sub-maximal stress Electrocardiogram, measures of stature, mass, central and limb girths as well as an oral glucose tolerance test (OGTT) and a total blood lipid profile. Participants took part in a 24-week progressive resistance training programme, consisting of three supervised sessions per week, each lasting 45 minutes and were not permitted to lose more than 10% of initial body mass during the 24-week study. All pre-test measures, excluding the stress ECG and the OGTT, were repeated every four weeks for the duration of the study. Results were that body mass, body mass index and waist-to-hip ratio did not change. Girth measures at mid-humerus, chest, waist, hip, mid-quadricep and mid-gastrocnemius all decreased significantly (p=0.05). LDL-cholesterol increased significantly over the course of 24 weeks (3.61mmol.L-1 to 4.07mmol.L-1) as did total cholesterol (5.81mmol.L-1 to 6.24mmol.L-1). Triglyceride concentration remained unchanged and HDL-cholesterol decreased significantly between the pre-test measure (1.55mmol.L-1) and the measure after six months (1.42mmol.L-1). It can be concluded that the blood lipid profile in a sample of post-menopausal women was not positively affected by a progressive resistance training programme over a 24 week period. , Maiden name: Kelly, Janet Erica
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The evolving image of the German Democratic republic as reflected in the works of Jurek Becker and Christa Wolf
- Authors: Williams, Alison Elizabeth
- Date: 2009
- Subjects: Becker, Jurek, 1937-1997 Wolf, Christa German fiction -- Germany (East) -- 20th Century Germany (East) -- History -- 20th Century Germany (East) In literature
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3584 , http://hdl.handle.net/10962/d1002159
- Description: The primary objective of this thesis is to demonstrate the direct relationship between history and literature, with particular reference to literature published in the German Democratic Republic. It explores the period of history from 1945 to 1990 describing the collapse of National Socialist Germany after World War Two; the formation of the Federal Republic of Germany in the West and the German Democratic Republic in the East in 1949; the historical, political and cultural evolution of East Germany until the fall of the Berlin Wall in November 1989, and finally the absorption of the German Democratic Republic into the Federal Republic of Germany in 1990.
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- Authors: Williams, Alison Elizabeth
- Date: 2009
- Subjects: Becker, Jurek, 1937-1997 Wolf, Christa German fiction -- Germany (East) -- 20th Century Germany (East) -- History -- 20th Century Germany (East) In literature
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3584 , http://hdl.handle.net/10962/d1002159
- Description: The primary objective of this thesis is to demonstrate the direct relationship between history and literature, with particular reference to literature published in the German Democratic Republic. It explores the period of history from 1945 to 1990 describing the collapse of National Socialist Germany after World War Two; the formation of the Federal Republic of Germany in the West and the German Democratic Republic in the East in 1949; the historical, political and cultural evolution of East Germany until the fall of the Berlin Wall in November 1989, and finally the absorption of the German Democratic Republic into the Federal Republic of Germany in 1990.
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The geological framework and depositional environments of the coal-bearing Karoo strata in the Central Kalahari Karoo Basin, Botswana
- Authors: Segwabe, Tebogo
- Date: 2009
- Subjects: Coal -- Geology -- Botswana , Sedimentation and deposition -- Botswana
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4955 , http://hdl.handle.net/10962/d1005567 , Coal -- Geology -- Botswana , Sedimentation and deposition -- Botswana
- Description: The investigation of the geological history (i.e., stratigraphy and sedimentology) and the dynamics of coal depositional environments, in particular, the forces responsible for changes in the accommodation space (e.g., subsidence vs. sedimentation rates) in the Permian coal-bearing Karoo strata in the Central Kalahari Karoo Basin (Botswana) revealed new details about the depositional processes and environments. Detailed review of the temporal and spatial stratigraphic variation of the coal-bearing Ecca Group successions via the analysis of facies changes based on core descriptions, gamma logs, field observations and palaeo-current measurements, lead to the identification of two main informal stratigraphic units, namely the Basal and Upper Units. The Basal Unit is characterised by an upward-coarsening succession, and it is interpreted as a product of a progradational deltaic setting (i.e., regressive deltaic cycle). This is followed by five sequences of fining-upward successions of sandstones and siltstones in the Upper Unit, interpreted as deposits of distributary channels (the basal arenaceous member) capped by finer argillaceous sequences of the deltaic floodplains (the upper coal-bearing member). The Upper Unit thus is interpreted as a delta plain facies association which was formed during transgressive phases when conditions for coal-quality peat accumulation (e.g., high water table) were present and the available accommodation space was partly controlled by tectonic uplift (repeated?) at basin margins. Limited palaeo-current analysis indicates deposition by channels flowing from the east, south-east and north-east. The lack of good quality exposures hampers the reconstruction of the plan form of the channel patterns. However, the little available evidence indicates a high-energy fluvio-deltaic system with irregular discharge and a high proportion of bedload sediments. Coal-seam thickness in the upper coal-bearing member reflect the complex control of the geological processes associated with and following peat formation, such as differential compaction of the underlying lithology, and the erosive or protective nature of the immediately overlying lithology.
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- Authors: Segwabe, Tebogo
- Date: 2009
- Subjects: Coal -- Geology -- Botswana , Sedimentation and deposition -- Botswana
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4955 , http://hdl.handle.net/10962/d1005567 , Coal -- Geology -- Botswana , Sedimentation and deposition -- Botswana
- Description: The investigation of the geological history (i.e., stratigraphy and sedimentology) and the dynamics of coal depositional environments, in particular, the forces responsible for changes in the accommodation space (e.g., subsidence vs. sedimentation rates) in the Permian coal-bearing Karoo strata in the Central Kalahari Karoo Basin (Botswana) revealed new details about the depositional processes and environments. Detailed review of the temporal and spatial stratigraphic variation of the coal-bearing Ecca Group successions via the analysis of facies changes based on core descriptions, gamma logs, field observations and palaeo-current measurements, lead to the identification of two main informal stratigraphic units, namely the Basal and Upper Units. The Basal Unit is characterised by an upward-coarsening succession, and it is interpreted as a product of a progradational deltaic setting (i.e., regressive deltaic cycle). This is followed by five sequences of fining-upward successions of sandstones and siltstones in the Upper Unit, interpreted as deposits of distributary channels (the basal arenaceous member) capped by finer argillaceous sequences of the deltaic floodplains (the upper coal-bearing member). The Upper Unit thus is interpreted as a delta plain facies association which was formed during transgressive phases when conditions for coal-quality peat accumulation (e.g., high water table) were present and the available accommodation space was partly controlled by tectonic uplift (repeated?) at basin margins. Limited palaeo-current analysis indicates deposition by channels flowing from the east, south-east and north-east. The lack of good quality exposures hampers the reconstruction of the plan form of the channel patterns. However, the little available evidence indicates a high-energy fluvio-deltaic system with irregular discharge and a high proportion of bedload sediments. Coal-seam thickness in the upper coal-bearing member reflect the complex control of the geological processes associated with and following peat formation, such as differential compaction of the underlying lithology, and the erosive or protective nature of the immediately overlying lithology.
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The governance and management of commonages in three small towns in the Eastern Cape, South Africa
- Authors: Martens, Claire
- Date: 2009
- Subjects: Commons -- Conservation -- South Africa -- Eastern Cape Natural resources, Communal -- Management -- South Africa -- Eastern Cape Rural development -- South Africa -- Eastern Cape Land tenure -- South Africa Land reform -- South Africa Property -- South Africa Property rights -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:4757 , http://hdl.handle.net/10962/d1007142
- Description: Commonage is land that is usually found adjacent to a town, which is owned by the local municipality and acquired through state grants or, historically, through the church. Since the new government dispensation in 1994, poor and previously disadvantaged residents have acquired access rights to commonage for agricultural purposes. Through the Department of Land Affair’s Commonage Programme, local municipalities are acquiring more commonage land for purposes of agriculture and grazing livestock. Commonages are increasingly being recognised as an important livelihood asset for the poor and unemployed residents’ of towns and rapid urbanisation is contributing to the increasing use of commonage for livelihood provisioning. Some municipalities view commonage as a key asset to promote Local Economic Development, while others are finding it difficult to manage the land effectively, to the extent that some analysts see tragic ecological consequences occurring due to over-grazing. This has been likened to the “tragedy of the commons” as advocated by Hardin in 1968. Commonage and common property resource systems have many similarities and co-management has been advocated as a potential management regime for commonage. Researching the policy framework, institutional structures and management bodies involved in commonage, gave a better understanding of the governance and management of the commonages in Grahamstown, Fort Beaufort and Bathurst. Current management attempts are not ensuring the efficient, equitable and sustainable use of these commonages. The governance framework is not adequately supporting proper management. In an environment of resource-poor institutional bodies, adaptive co-management could prove to be the most effective system to ensure the sustainable use and development of this natural resource. Furthermore, commonage is no longer contributing to the Land Reform Programme. Commonage should be better integrated into agrarian reform through lease schemes and an efficient Emerging Farmer Programme.
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- Authors: Martens, Claire
- Date: 2009
- Subjects: Commons -- Conservation -- South Africa -- Eastern Cape Natural resources, Communal -- Management -- South Africa -- Eastern Cape Rural development -- South Africa -- Eastern Cape Land tenure -- South Africa Land reform -- South Africa Property -- South Africa Property rights -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:4757 , http://hdl.handle.net/10962/d1007142
- Description: Commonage is land that is usually found adjacent to a town, which is owned by the local municipality and acquired through state grants or, historically, through the church. Since the new government dispensation in 1994, poor and previously disadvantaged residents have acquired access rights to commonage for agricultural purposes. Through the Department of Land Affair’s Commonage Programme, local municipalities are acquiring more commonage land for purposes of agriculture and grazing livestock. Commonages are increasingly being recognised as an important livelihood asset for the poor and unemployed residents’ of towns and rapid urbanisation is contributing to the increasing use of commonage for livelihood provisioning. Some municipalities view commonage as a key asset to promote Local Economic Development, while others are finding it difficult to manage the land effectively, to the extent that some analysts see tragic ecological consequences occurring due to over-grazing. This has been likened to the “tragedy of the commons” as advocated by Hardin in 1968. Commonage and common property resource systems have many similarities and co-management has been advocated as a potential management regime for commonage. Researching the policy framework, institutional structures and management bodies involved in commonage, gave a better understanding of the governance and management of the commonages in Grahamstown, Fort Beaufort and Bathurst. Current management attempts are not ensuring the efficient, equitable and sustainable use of these commonages. The governance framework is not adequately supporting proper management. In an environment of resource-poor institutional bodies, adaptive co-management could prove to be the most effective system to ensure the sustainable use and development of this natural resource. Furthermore, commonage is no longer contributing to the Land Reform Programme. Commonage should be better integrated into agrarian reform through lease schemes and an efficient Emerging Farmer Programme.
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The ichthyofauna associated with Taylor's salt marsh, Kariega estuary (Eastern Cape), South Africa
- Authors: Booth, Tara Loren
- Date: 2009
- Subjects: Fishes -- South Africa -- Eastern Cape , Estuaries -- South Africa -- Eastern Cape , Fish communities -- South Africa -- Eastern Cape , Salt marsh animals -- South Africa -- Eastern Cape , Eelgrass -- South Africa -- Eastern Cape , Gray mullets -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5710 , http://hdl.handle.net/10962/d1005396 , Fishes -- South Africa -- Eastern Cape , Estuaries -- South Africa -- Eastern Cape , Fish communities -- South Africa -- Eastern Cape , Salt marsh animals -- South Africa -- Eastern Cape , Eelgrass -- South Africa -- Eastern Cape , Gray mullets -- South Africa -- Eastern Cape
- Description: The spatial and temporal patterns in the ichthyofaunal community composition and structure in Taylor’s salt marsh and adjacent eelgrass beds (Zostera capensis) in the Kariega Estuary, was investigated every two months between May 2006 and March 2007. Total ichthyofaunal abundances and biomass in the salt marsh ranged between 0.55 and 21.7 ind.10m-2 and between 0.03 and 1.9 g.wwt.10m⁻², respectively. There were no significant spatial patterns in the values evident (P > 0.05 in all cases) although seasonal trends were marked, with highest values consistently recorded during the warmer summer months. Investigations into the community structure showed that the ichthyofaunal community within salt marsh was composed almost exclusively of juveniles of estuarine dependant (category II) species, mainly juvenile Mugilidae (<20mm SL) that comprised up to 83% of all fish sampled. Hierarchical cluster analysis and multidimensional scaling did not identify any distinct spatial patterns in the ichthyofaunal community within the salt marsh. The absence of any spatial patterns in the community structure could be related to the absence of any significant spatial patterns in the physico-chemical (temperature, salinity and dissolved oxygen concentrations) and biological (water column and microphytobenthic algal concentrations) variables within the salt marsh (P > 0.05 in all cases). Temporal shifts in the ichthyofaunal community structure within the salt marsh were, however, evident largely reflecting the breeding cycles of individual species within the sub-region. Within the adjacent eelgrass beds, total ichthyofaunal abundances and biomass ranged between 8.4 and 49.4 ind.10m⁻² and between 2.9 and 94.5 g.wwt.10m⁻², respectively. Once again there were no distinct spatial patterns in the abundance and biomass values evident although seasonal patterns were marked. In contrast to the salt marsh, within the in the eelgrass community, there were a large number of adult individuals recorded. Again category II species, the estuarine dependent species, were numerically and gravimetrically dominant. The dominance of category II species reflects the marine dominance of Kariega Estuary. The remaining estuarine utilisation categories did not contribute significantly to abundance or standing stock totals. Hierarchical cluster analysis showed that the salt marsh and eelgrass beds represented two distinct habitats within the Kariega Estuary. Within the salt marsh, the family Mugilidae were numerically dominant contributing 83% of the total catch. Within the eelgrass beds, the sparid, Rhabdosargus holubi and representatives of the family Gobidae contributed 36.3% and 33.9% respectively to the total catch. Estuaries with a wide range of microhabitats have been demonstrated to support a more diverse ichthyofaunal community. Shallow water habitats in general are important areas for juvenile fish within estuaries. Taylor’s salt marsh provides an alternative shallow water habitat, occupied by a distinct ichthyofaunal community composition, with increased food availability and decreased predation pressure, for a wide range of fish species.
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- Authors: Booth, Tara Loren
- Date: 2009
- Subjects: Fishes -- South Africa -- Eastern Cape , Estuaries -- South Africa -- Eastern Cape , Fish communities -- South Africa -- Eastern Cape , Salt marsh animals -- South Africa -- Eastern Cape , Eelgrass -- South Africa -- Eastern Cape , Gray mullets -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5710 , http://hdl.handle.net/10962/d1005396 , Fishes -- South Africa -- Eastern Cape , Estuaries -- South Africa -- Eastern Cape , Fish communities -- South Africa -- Eastern Cape , Salt marsh animals -- South Africa -- Eastern Cape , Eelgrass -- South Africa -- Eastern Cape , Gray mullets -- South Africa -- Eastern Cape
- Description: The spatial and temporal patterns in the ichthyofaunal community composition and structure in Taylor’s salt marsh and adjacent eelgrass beds (Zostera capensis) in the Kariega Estuary, was investigated every two months between May 2006 and March 2007. Total ichthyofaunal abundances and biomass in the salt marsh ranged between 0.55 and 21.7 ind.10m-2 and between 0.03 and 1.9 g.wwt.10m⁻², respectively. There were no significant spatial patterns in the values evident (P > 0.05 in all cases) although seasonal trends were marked, with highest values consistently recorded during the warmer summer months. Investigations into the community structure showed that the ichthyofaunal community within salt marsh was composed almost exclusively of juveniles of estuarine dependant (category II) species, mainly juvenile Mugilidae (<20mm SL) that comprised up to 83% of all fish sampled. Hierarchical cluster analysis and multidimensional scaling did not identify any distinct spatial patterns in the ichthyofaunal community within the salt marsh. The absence of any spatial patterns in the community structure could be related to the absence of any significant spatial patterns in the physico-chemical (temperature, salinity and dissolved oxygen concentrations) and biological (water column and microphytobenthic algal concentrations) variables within the salt marsh (P > 0.05 in all cases). Temporal shifts in the ichthyofaunal community structure within the salt marsh were, however, evident largely reflecting the breeding cycles of individual species within the sub-region. Within the adjacent eelgrass beds, total ichthyofaunal abundances and biomass ranged between 8.4 and 49.4 ind.10m⁻² and between 2.9 and 94.5 g.wwt.10m⁻², respectively. Once again there were no distinct spatial patterns in the abundance and biomass values evident although seasonal patterns were marked. In contrast to the salt marsh, within the in the eelgrass community, there were a large number of adult individuals recorded. Again category II species, the estuarine dependent species, were numerically and gravimetrically dominant. The dominance of category II species reflects the marine dominance of Kariega Estuary. The remaining estuarine utilisation categories did not contribute significantly to abundance or standing stock totals. Hierarchical cluster analysis showed that the salt marsh and eelgrass beds represented two distinct habitats within the Kariega Estuary. Within the salt marsh, the family Mugilidae were numerically dominant contributing 83% of the total catch. Within the eelgrass beds, the sparid, Rhabdosargus holubi and representatives of the family Gobidae contributed 36.3% and 33.9% respectively to the total catch. Estuaries with a wide range of microhabitats have been demonstrated to support a more diverse ichthyofaunal community. Shallow water habitats in general are important areas for juvenile fish within estuaries. Taylor’s salt marsh provides an alternative shallow water habitat, occupied by a distinct ichthyofaunal community composition, with increased food availability and decreased predation pressure, for a wide range of fish species.
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The impact of angling on smallmouth and largemouth yellowfish, labeobarbus aeneus and labeobarbus kimberleyensis, in Lake Gariep, South Africa
- Authors: Ellender, Bruce Robert
- Date: 2009
- Subjects: Barbus aeneus , Largemouth bass , Labeobarbus , Fishing -- South Africa -- Gariep Dam
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5289 , http://hdl.handle.net/10962/d1005133 , Barbus aeneus , Largemouth bass , Labeobarbus , Fishing -- South Africa -- Gariep Dam
- Description: A large sportfishery that targets both smallmouth (Labeobarbus aeneus) and largemouth (Labeobarbus kimberleyensis) yellowfish exists in South Africa. Both species have high conservation priority, and no assessments documenting the effect of angling on L. aeneus and L. kimberleyensis have been undertaken. The overall aim of this study was to provide an assessment of the impact of angling on L. aeneus and L. kimberleyensis. The specific objectives of this study were to characterise the sectors utilising Lake Gariep, document catch, effort and total catch for the fishery as well as the locality specific biology of L. aeneus and L. kimberleyensis. The study was undertaken on Lake Gariep, South Africa's largest impoundment, situated on the Orange River system in central South Africa. Subsistence fishers were the dominant user group, constituting 60 % of the fishery, the remainder constituted recreational anglers. Angler catches were dominated by carp (Cyprinus carpio; 74 %), followed by mudfish (Labeo capensis; 13 %) and smallmouth yellowfish (8 %). Catches of largemouth yellowfish contributed < 0.5 % to the total catch. The relative abundance of species by weight differed by area (χ² test of independence: χ² = 182, df = 4, p ≤ 0.05). On any sampling day time fished was the best predictor for differences in probability of capture (PC) (Wald X²(1) = 7.169, p = 0.007). The probability of capturing L. aeneus differed significantly between month (Wald X²(5) = 20.690, p = 0.000) and region (Wald X²(3) = 46.755, p = 0.000). The single best predictor of differences in log abundance and non-zero CPUE was region (Factorial ANOVA p ≤ 0.05). Mean CPUE ranged from 0.21 ± 0.06 kg. man⁻¹.hr⁻¹ to 0.82 ± 0.11 kg. man⁻¹.hr⁻¹ in the OV region and 0.42 ± 0.10 kg. man⁻¹.hr⁻¹ to 1.17 ± 0.24 kg. man⁻¹.hr⁻¹ in the GD region. Angler effort was higher in OV than in GD and ranged from 17 ± 3 anglers/day to 45 ± 9 anglers/day and 6 ± 1 anglers/day to 41 ± 8 anglers/day, respectively. Total catch was higher in the GD 46.0 [95 % CI = 15:102.6] t. period⁻¹ than the OV region 40.0 [95 % CI = 13.9:89.6] t. period⁻¹. The total catch from the Lake Gariep fishery between March and December 2007 was estimated to be 86.0 [95 % CI = 40.4:154.8] t. period⁻¹. Age and growth was determined using whole otoliths. The growth of L. aeneus was best described by the von Bertalanffy growth model as Lt = 481.80 (1- e⁻°·²²⁽t⁺°·⁶¹⁾). Gonadal development for L. aeneus was seasonal, with the gonadosomatic index peaking in January, revealing a distinct spawning season. The length at 50 % maturity for female L. aeneus was attained at a fork length of 354.7 mm. Natural mortality (M) was estimated at 0.55 year⁻¹. The growth of L. kimberleyensis was described by the von Bertalanffy growth model as Lt = 763.22 (1- e⁻°·¹¹⁽t⁺°·⁶³⁾). Only 6 mature female and 15 mature male L. kimberleyensis were recorded during the study period. The smallest mature female was a 390 mm FL stage four female and the earliest recorded mature male was a 337 mm FL, ripe running male. Natural mortality (M) was estimated at 0.08 year⁻¹ for L. kimberleyensis. Per recruit analysis indicated that current fishing mortality reduces the L. aeneus spawner biomass by 7 %, which is considered negligible. Labeobarbus kimberleyensis forms an insignificant proportion of anglers catches and stock status is currently considered pristine.
- Full Text:
- Authors: Ellender, Bruce Robert
- Date: 2009
- Subjects: Barbus aeneus , Largemouth bass , Labeobarbus , Fishing -- South Africa -- Gariep Dam
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5289 , http://hdl.handle.net/10962/d1005133 , Barbus aeneus , Largemouth bass , Labeobarbus , Fishing -- South Africa -- Gariep Dam
- Description: A large sportfishery that targets both smallmouth (Labeobarbus aeneus) and largemouth (Labeobarbus kimberleyensis) yellowfish exists in South Africa. Both species have high conservation priority, and no assessments documenting the effect of angling on L. aeneus and L. kimberleyensis have been undertaken. The overall aim of this study was to provide an assessment of the impact of angling on L. aeneus and L. kimberleyensis. The specific objectives of this study were to characterise the sectors utilising Lake Gariep, document catch, effort and total catch for the fishery as well as the locality specific biology of L. aeneus and L. kimberleyensis. The study was undertaken on Lake Gariep, South Africa's largest impoundment, situated on the Orange River system in central South Africa. Subsistence fishers were the dominant user group, constituting 60 % of the fishery, the remainder constituted recreational anglers. Angler catches were dominated by carp (Cyprinus carpio; 74 %), followed by mudfish (Labeo capensis; 13 %) and smallmouth yellowfish (8 %). Catches of largemouth yellowfish contributed < 0.5 % to the total catch. The relative abundance of species by weight differed by area (χ² test of independence: χ² = 182, df = 4, p ≤ 0.05). On any sampling day time fished was the best predictor for differences in probability of capture (PC) (Wald X²(1) = 7.169, p = 0.007). The probability of capturing L. aeneus differed significantly between month (Wald X²(5) = 20.690, p = 0.000) and region (Wald X²(3) = 46.755, p = 0.000). The single best predictor of differences in log abundance and non-zero CPUE was region (Factorial ANOVA p ≤ 0.05). Mean CPUE ranged from 0.21 ± 0.06 kg. man⁻¹.hr⁻¹ to 0.82 ± 0.11 kg. man⁻¹.hr⁻¹ in the OV region and 0.42 ± 0.10 kg. man⁻¹.hr⁻¹ to 1.17 ± 0.24 kg. man⁻¹.hr⁻¹ in the GD region. Angler effort was higher in OV than in GD and ranged from 17 ± 3 anglers/day to 45 ± 9 anglers/day and 6 ± 1 anglers/day to 41 ± 8 anglers/day, respectively. Total catch was higher in the GD 46.0 [95 % CI = 15:102.6] t. period⁻¹ than the OV region 40.0 [95 % CI = 13.9:89.6] t. period⁻¹. The total catch from the Lake Gariep fishery between March and December 2007 was estimated to be 86.0 [95 % CI = 40.4:154.8] t. period⁻¹. Age and growth was determined using whole otoliths. The growth of L. aeneus was best described by the von Bertalanffy growth model as Lt = 481.80 (1- e⁻°·²²⁽t⁺°·⁶¹⁾). Gonadal development for L. aeneus was seasonal, with the gonadosomatic index peaking in January, revealing a distinct spawning season. The length at 50 % maturity for female L. aeneus was attained at a fork length of 354.7 mm. Natural mortality (M) was estimated at 0.55 year⁻¹. The growth of L. kimberleyensis was described by the von Bertalanffy growth model as Lt = 763.22 (1- e⁻°·¹¹⁽t⁺°·⁶³⁾). Only 6 mature female and 15 mature male L. kimberleyensis were recorded during the study period. The smallest mature female was a 390 mm FL stage four female and the earliest recorded mature male was a 337 mm FL, ripe running male. Natural mortality (M) was estimated at 0.08 year⁻¹ for L. kimberleyensis. Per recruit analysis indicated that current fishing mortality reduces the L. aeneus spawner biomass by 7 %, which is considered negligible. Labeobarbus kimberleyensis forms an insignificant proportion of anglers catches and stock status is currently considered pristine.
- Full Text: