National case study : teacher professional development with an education for sustainable development focus in South Africa: development of a network, curriculum framework and resources for teacher education
- Authors: Lotz-Sisitka, Heila
- Date: 2011
- Subjects: Teachers -- Training of , Career development , Sustainable development -- South Africa
- Language: English
- Type: article , text
- Identifier: http://hdl.handle.net/10962/59646 , vital:27634 , https://www.ajol.info/index.php/sajee/article/view/122242
- Description: This national case study reports on the development of a national network, curriculum framework and resources for teacher education, with specific focus on the inclusion of environment and sustainability, also known as education for sustainable development (ESD) in the South African teacher education system. It reviews and reports on the history of environment and sustainability education in teacher education, and from this, the national case study begins to conceptualise a new approach to environment and sustainability teacher education within a new curriculum policy environment, and a new teacher education and development policy environment. Action research case study methodology is used to document the first phase of the emergence of this network, and this report covers Phase 1 of the initiative, which covers formation of the network, review of previous practices, three conceptual development pilot studies undertaken in both in-service and pre-service teacher education environments and a piloting of a ‘Train the Trainers’ or ‘Educate the Teacher Educators’ programme, which complements and extends the actual teacher education and development (TED) programme under development. The study highlights critical insights of relevance to the shift to a content referenced curriculum in South Africa, and shows how the ‘knowledge mix’ which forms the foundation of the new Teacher Education Qualifications Framework can be engaged. It also highlights some features of the changing knowledge environment, and what dominant knowledge practices are in environment and sustainability-related teaching and teacher education practices, opening these up for further scrutiny. It raises concerns that dominant knowledge work, while integrating a range of forms of knowledge (as is expected of the teacher education system under the new policy), tends to be limited by content on problems and issues for raising awareness, and fails to develop deeper conceptual depth and understanding of environment and sustainability, as issues based knowledge dominates. Similarly, it fails to support social innovation as a response to environment and sustainability concerns, as awareness raising dominates in dominant knowledge work. The study provides a revised conceptual framework for the Teacher Development Network (TEDN) programme, with guidance on key elements necessary to take the programme forward in Phase 2.
- Full Text:
- Authors: Lotz-Sisitka, Heila
- Date: 2011
- Subjects: Teachers -- Training of , Career development , Sustainable development -- South Africa
- Language: English
- Type: article , text
- Identifier: http://hdl.handle.net/10962/59646 , vital:27634 , https://www.ajol.info/index.php/sajee/article/view/122242
- Description: This national case study reports on the development of a national network, curriculum framework and resources for teacher education, with specific focus on the inclusion of environment and sustainability, also known as education for sustainable development (ESD) in the South African teacher education system. It reviews and reports on the history of environment and sustainability education in teacher education, and from this, the national case study begins to conceptualise a new approach to environment and sustainability teacher education within a new curriculum policy environment, and a new teacher education and development policy environment. Action research case study methodology is used to document the first phase of the emergence of this network, and this report covers Phase 1 of the initiative, which covers formation of the network, review of previous practices, three conceptual development pilot studies undertaken in both in-service and pre-service teacher education environments and a piloting of a ‘Train the Trainers’ or ‘Educate the Teacher Educators’ programme, which complements and extends the actual teacher education and development (TED) programme under development. The study highlights critical insights of relevance to the shift to a content referenced curriculum in South Africa, and shows how the ‘knowledge mix’ which forms the foundation of the new Teacher Education Qualifications Framework can be engaged. It also highlights some features of the changing knowledge environment, and what dominant knowledge practices are in environment and sustainability-related teaching and teacher education practices, opening these up for further scrutiny. It raises concerns that dominant knowledge work, while integrating a range of forms of knowledge (as is expected of the teacher education system under the new policy), tends to be limited by content on problems and issues for raising awareness, and fails to develop deeper conceptual depth and understanding of environment and sustainability, as issues based knowledge dominates. Similarly, it fails to support social innovation as a response to environment and sustainability concerns, as awareness raising dominates in dominant knowledge work. The study provides a revised conceptual framework for the Teacher Development Network (TEDN) programme, with guidance on key elements necessary to take the programme forward in Phase 2.
- Full Text:
Near Real-time Aggregation and Visualisation of Hostile Network Traffic
- Hunter, Samuel O, Irwin, Barry V W
- Authors: Hunter, Samuel O , Irwin, Barry V W
- Date: 2011
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/428067 , vital:72484 , https://www.researchgate.net/profile/Barry-Irwin/publication/327622653_Near_Real-time_Aggregation_and_Visualisation_of_Hostile_Network_Traffic/links/5b9a1474a6fdcc59bf8dfcc2/Near-Real-time-Aggregation-and-Visualisation-of-Hostile-Network-Traffic.pdf4
- Description: Efficient utilization of hostile network traffic for visualization and defen-sive purposes require near real-time availability of such data. Hostile or malicious traffic was obtained through the use of network telescopes and honeypots, as they are effective at capturing mostly illegitimate and nefarious traffic. The data is then exposed in near real-time through a messaging framework and visualized with the help of a geolocation based visualization tool. Defensive applications with regards to hostile network traffic are explored; these include the dynamic quarantine of malicious hosts internal to a network and the egress filtering of denial of service traffic originating from inside a network.
- Full Text:
- Authors: Hunter, Samuel O , Irwin, Barry V W
- Date: 2011
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/428067 , vital:72484 , https://www.researchgate.net/profile/Barry-Irwin/publication/327622653_Near_Real-time_Aggregation_and_Visualisation_of_Hostile_Network_Traffic/links/5b9a1474a6fdcc59bf8dfcc2/Near-Real-time-Aggregation-and-Visualisation-of-Hostile-Network-Traffic.pdf4
- Description: Efficient utilization of hostile network traffic for visualization and defen-sive purposes require near real-time availability of such data. Hostile or malicious traffic was obtained through the use of network telescopes and honeypots, as they are effective at capturing mostly illegitimate and nefarious traffic. The data is then exposed in near real-time through a messaging framework and visualized with the help of a geolocation based visualization tool. Defensive applications with regards to hostile network traffic are explored; these include the dynamic quarantine of malicious hosts internal to a network and the egress filtering of denial of service traffic originating from inside a network.
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Negotiating the global : how young women in Nairobi shape their local identities in response to aspects of the mexican telenovela, Cuando seas mia
- Authors: Jiwaji, Aamera Hamzaali
- Date: 2011 , 2010-09-15
- Subjects: Cuando seas mia (Television program) , Television soap operas -- Kenya , Motion pictures and youth -- Kenya , Emigration and immigration in motion pictures -- Kenya , Ethnicity in motion pictures -- Kenya , Arts and society -- Kenya
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3532 , http://hdl.handle.net/10962/d1013364
- Description: Latin American telenovelas have been exported to more than a hundred countries across the globe. While they are popular in their country of production because their messages resonate with their audience’s everyday experiences, their popularity amongst global audiences with whom they share neither a social nor a cultural history is unexplained. Kenya has been importing and airing Latin American telenovelas since the early 1990s, and telenovelas have permeated many aspects of Kenyan daily life, when compared to other foreign globally-distributed media products that are aired on Kenyan television. As global media products, telenovelas remain open to criticisms from the media imperialism thesis. This research adopts an ethnographic approach to the study of audiences, and looks at the reception of a Mexican telenovela, Cuando Seas Mia, by a group of young Kenyan women in Nairobi. It reflects upon the media imperialism thesis from an African perspective by investigating the meanings that these women make from Cuando Seas Mia, and how these shape their changing local identities and cultures. The young women in this study, most of whom have moved to the city from the rural areas, are influenced by traditional, patriarchal Kenyan society and by the modern, Western influences of an urban environment. They experience a tension between their evolving rural and urban roles and identities and are drawn to telenovelas because their exploration of rural-urban themes holds a relevance to their own lives. They negotiate their contemporary African youth identities, gender roles and heterosexual relationships in relation to representations in the telenovela, questioning and destabilising African and Western definitions. These women select aspects from their traditional, African cultures and from their modern, Western experiences (and consumption of global media) and reconstruct them into a transitional youth identity which suits their day to day lives as young women living in an urban African environment.
- Full Text:
- Authors: Jiwaji, Aamera Hamzaali
- Date: 2011 , 2010-09-15
- Subjects: Cuando seas mia (Television program) , Television soap operas -- Kenya , Motion pictures and youth -- Kenya , Emigration and immigration in motion pictures -- Kenya , Ethnicity in motion pictures -- Kenya , Arts and society -- Kenya
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3532 , http://hdl.handle.net/10962/d1013364
- Description: Latin American telenovelas have been exported to more than a hundred countries across the globe. While they are popular in their country of production because their messages resonate with their audience’s everyday experiences, their popularity amongst global audiences with whom they share neither a social nor a cultural history is unexplained. Kenya has been importing and airing Latin American telenovelas since the early 1990s, and telenovelas have permeated many aspects of Kenyan daily life, when compared to other foreign globally-distributed media products that are aired on Kenyan television. As global media products, telenovelas remain open to criticisms from the media imperialism thesis. This research adopts an ethnographic approach to the study of audiences, and looks at the reception of a Mexican telenovela, Cuando Seas Mia, by a group of young Kenyan women in Nairobi. It reflects upon the media imperialism thesis from an African perspective by investigating the meanings that these women make from Cuando Seas Mia, and how these shape their changing local identities and cultures. The young women in this study, most of whom have moved to the city from the rural areas, are influenced by traditional, patriarchal Kenyan society and by the modern, Western influences of an urban environment. They experience a tension between their evolving rural and urban roles and identities and are drawn to telenovelas because their exploration of rural-urban themes holds a relevance to their own lives. They negotiate their contemporary African youth identities, gender roles and heterosexual relationships in relation to representations in the telenovela, questioning and destabilising African and Western definitions. These women select aspects from their traditional, African cultures and from their modern, Western experiences (and consumption of global media) and reconstruct them into a transitional youth identity which suits their day to day lives as young women living in an urban African environment.
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Neogene fluvial deposits along the south-west coast of South Africa understanding the palaeoclimate through proxies
- Authors: Sciscio, Lara
- Date: 2011
- Subjects: Alluvium , Paleoclimatology -- South Africa , Paleoecology -- Miocene -- South Africa , Paleobotany -- Miocene -- South Africa , Paleogeography -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4981 , http://hdl.handle.net/10962/d1005593 , Alluvium , Paleoclimatology -- South Africa , Paleoecology -- Miocene -- South Africa , Paleobotany -- Miocene -- South Africa , Paleogeography -- South Africa
- Description: Branched glycerol dialkyl glycerol tetraether (GDGTs) membrane lipids have been used as a new proxy for the reconstruction of terrestrial palaeoclimates. These biomarkers (or molecular ‗fossils‘) in conjunction with palynology, have been effective in the novel analysis of Miocene organic-rich sediments from three South African west coast sites at Rondeberg, Noordhoek and Langebaanweg. Lastly, a Quaternary south coast site at Rietvlei, South Africa, was also studied to further elucidate the extent of use of this new proxy. The fluvial peat and organic-rich deposits of the Elandsfontyn Formation (Sandveld Group) were investigated at Noordhoek, Langebaanweg and Rondeberg to provide new evidence for the climate and vegetation patterns during Miocene in this region. Drill-core and quarry samples from all four sites were freeze-dried, powered, and prepared for biogeochemical and palynological analyses. The methylation index of branched tetraethers (MBT) and cyclisation ratio of branched tetraethers (CBT) proxies were used to calculate the mean annual air temperature (MAAT) and pH values of the organic-rich horizons at time of deposition. The Branched versus isoprenoid index of tetraethers (BIT) was used to assess the relative contributions of marine archaeal and terrestrial bacterial tetraethers, and thereby assess the validity of the MBT, CBT and calculated palaeoenvironmental factors. The results presented in this thesis suggest that the use of the MBT/CBT proxy has significant potential in southern Africa, and may complement previously attempted palaeoclimatic and palaeoecological studies of Neogene-aged South African sediments. This type of research has the capacity to provide palaeoenvironmental information where other proxies may be absent. Results indicate that all sites yielded branched tetraether membrane lipids with the exception of Rondeberg, where GDGTs were below detection as a result of poor preservation conditions. Palynological investigation confirmed proxy derived temperatures. Furthermore palynomorph analyses supplemented earlier studies of the Noordhoek site and were piloted for the Rondeberg site, reaffirming alternating sequences of tropical and subtropical palynofloras. The MAATs, likewise, show variability and pronounced trends through time at the Langebaanweg and Noordhoek sites, generally corresponding with the variation and diversity of the pollen population. The terrestrial MAAT results appear to compliment Southern Hemisphere sea level changes associated with Antarctic glaciations. Additionally, this data shows a pattern similar to the Southern and Northern Hemisphere marine isotope records of relative fluctuations in the global climate and sea level change from the early to middle Miocene. The application of these past climate change indicators have been proved to be useful in the reconstruction of South Africa Miocene palaeoclimates, and may aid in understanding the consequences of climate change in the Cape region.
- Full Text:
- Authors: Sciscio, Lara
- Date: 2011
- Subjects: Alluvium , Paleoclimatology -- South Africa , Paleoecology -- Miocene -- South Africa , Paleobotany -- Miocene -- South Africa , Paleogeography -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4981 , http://hdl.handle.net/10962/d1005593 , Alluvium , Paleoclimatology -- South Africa , Paleoecology -- Miocene -- South Africa , Paleobotany -- Miocene -- South Africa , Paleogeography -- South Africa
- Description: Branched glycerol dialkyl glycerol tetraether (GDGTs) membrane lipids have been used as a new proxy for the reconstruction of terrestrial palaeoclimates. These biomarkers (or molecular ‗fossils‘) in conjunction with palynology, have been effective in the novel analysis of Miocene organic-rich sediments from three South African west coast sites at Rondeberg, Noordhoek and Langebaanweg. Lastly, a Quaternary south coast site at Rietvlei, South Africa, was also studied to further elucidate the extent of use of this new proxy. The fluvial peat and organic-rich deposits of the Elandsfontyn Formation (Sandveld Group) were investigated at Noordhoek, Langebaanweg and Rondeberg to provide new evidence for the climate and vegetation patterns during Miocene in this region. Drill-core and quarry samples from all four sites were freeze-dried, powered, and prepared for biogeochemical and palynological analyses. The methylation index of branched tetraethers (MBT) and cyclisation ratio of branched tetraethers (CBT) proxies were used to calculate the mean annual air temperature (MAAT) and pH values of the organic-rich horizons at time of deposition. The Branched versus isoprenoid index of tetraethers (BIT) was used to assess the relative contributions of marine archaeal and terrestrial bacterial tetraethers, and thereby assess the validity of the MBT, CBT and calculated palaeoenvironmental factors. The results presented in this thesis suggest that the use of the MBT/CBT proxy has significant potential in southern Africa, and may complement previously attempted palaeoclimatic and palaeoecological studies of Neogene-aged South African sediments. This type of research has the capacity to provide palaeoenvironmental information where other proxies may be absent. Results indicate that all sites yielded branched tetraether membrane lipids with the exception of Rondeberg, where GDGTs were below detection as a result of poor preservation conditions. Palynological investigation confirmed proxy derived temperatures. Furthermore palynomorph analyses supplemented earlier studies of the Noordhoek site and were piloted for the Rondeberg site, reaffirming alternating sequences of tropical and subtropical palynofloras. The MAATs, likewise, show variability and pronounced trends through time at the Langebaanweg and Noordhoek sites, generally corresponding with the variation and diversity of the pollen population. The terrestrial MAAT results appear to compliment Southern Hemisphere sea level changes associated with Antarctic glaciations. Additionally, this data shows a pattern similar to the Southern and Northern Hemisphere marine isotope records of relative fluctuations in the global climate and sea level change from the early to middle Miocene. The application of these past climate change indicators have been proved to be useful in the reconstruction of South Africa Miocene palaeoclimates, and may aid in understanding the consequences of climate change in the Cape region.
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Network neutral control over quality of service networks
- Foulkes, Phillip, Foss, Richard, Gurdan, Robby
- Authors: Foulkes, Phillip , Foss, Richard , Gurdan, Robby
- Date: 2011
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/427166 , vital:72419 , https://www.aes.org/e-lib/online/browse.cfm?elib=16151
- Description: Creating interoperability between two standards-based network technologies, IEEE 1394 Firewire and Ethernet Audio/Video Bridging (AVB), allows them to exist simultaneously in a single application configuration. While both technologies provide the transport of synchronized, low-latency, real-time audio and video data, they have different approaches to enabling this transport. By using a compatible audio gateway with a common control protocol, audio devices on these disparate networks can be connected and controlled.
- Full Text:
- Authors: Foulkes, Phillip , Foss, Richard , Gurdan, Robby
- Date: 2011
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/427166 , vital:72419 , https://www.aes.org/e-lib/online/browse.cfm?elib=16151
- Description: Creating interoperability between two standards-based network technologies, IEEE 1394 Firewire and Ethernet Audio/Video Bridging (AVB), allows them to exist simultaneously in a single application configuration. While both technologies provide the transport of synchronized, low-latency, real-time audio and video data, they have different approaches to enabling this transport. By using a compatible audio gateway with a common control protocol, audio devices on these disparate networks can be connected and controlled.
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Neuronal nitric oxide synthase : a biomarker for Alzheimers disease : interaction of neuronal nitric oxide synthase with beta-amyloid peptides in the brain
- Authors: Padayachee, Eden Rebecca
- Date: 2011 , 2013-07-19
- Subjects: Alzheimer's disease , Nitric-oxide synthase , Biochemical markers , Amyloid beta-protein , Peptide hormones
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4086 , http://hdl.handle.net/10962/d1007677 , Alzheimer's disease , Nitric-oxide synthase , Biochemical markers , Amyloid beta-protein , Peptide hormones
- Description: High levels of the amino acid arginine and low levels of the product citrulline in the cerebrospinal fluid of Alzheimer's patients could mean that there is a decrease in the enzymes that metabolize this amino acid. One such enzyme is neuronal nitric oxide synthase (nNOS). In this study, neuronal nitric oxide synthase (nNOS), sourced from bovine brain was extracted and concentrated using two methods of precipitation: poly (ethylene glycol) 20 000 (PEG) and ammonium sulphate [(NH₄)₂S0₄). These two techniques gave no increase in yield nor fold purification and hence were abandoned in favour of ion exchange chromatography by DEAE-Sepharose. The enzyme was then successfully purified by anion-exchange and after dialysis produced a 38% yield and three fold purification and yielded the highest specific activity of 2.27 U/mg. Neuronal nitric oxide synthase (nNOS) was a heterodimeric protein with a total molecular mass of ± 225 kDa (95 and 130 kDa monomers). The temperature and pH optima of the enzyme were 40⁰C and 6.5, respectively. The kinetic parameters (KM and Vmax) of nNOS were 70 μM and 0.332 μmol.min⁻¹, respectively. Moreover neuronal nitric oxide synthase (nNOS) was relatively stable at 40⁰C (t½ = 3 h). It was also confirmed that β-amyloid peptides inhibited nNOS when bound to the enzyme and that nNOS behaved as a catalyst in fibril formation through association-dissociation between enzyme and β-amyloid peptide. It was further shown that Aβ₁₇₋₂₈ inhibited nNOS the most with a Ki of 1.92 μM and also had the highest Stern-Volmer value (Ksv) of 0.11 μM⁻¹ indicating tight binding affinity to nNOS and easier accessibility to fluor molecules during binding. Congo red, turbidity, thioflavin-T assays and transmission electron microscopy were successfully used to detect and visualize the presence of fibrils by studying the process of fibrillogenesis. Computerized molecular modeling successfully studied protein dynamics and conformational changes of nNOS. These results correlated with resonance energy transfer (FRET) results which revealed the distance of tryptophan residues from the arginine bound at enzyme active site. Both the aforementioned techniques revealed that in the natural state of the enzyme with arginine bound at the active site, the tryptophan residues (TRP₆₂₅ and TRP₇₂₁) were positioned at the surface of the enzyme 28 Å away from the active site. When the amyloid peptide (Aβ₁₇₋₂₈) was bound to the active site, these same two amino acids moved 14 Å closer to the active site. A five residue hydrophobic fragment Aβ₁₇₋₂₁ [Leu₁₇ - Val₁₈ - Phe₁₉ - Phe₂₀ - Ala₁] within Aβ₁₇₋₂₈ was shown by computer modeling to be critical to the binding of the peptide to the active site of nNOS.
- Full Text:
- Authors: Padayachee, Eden Rebecca
- Date: 2011 , 2013-07-19
- Subjects: Alzheimer's disease , Nitric-oxide synthase , Biochemical markers , Amyloid beta-protein , Peptide hormones
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4086 , http://hdl.handle.net/10962/d1007677 , Alzheimer's disease , Nitric-oxide synthase , Biochemical markers , Amyloid beta-protein , Peptide hormones
- Description: High levels of the amino acid arginine and low levels of the product citrulline in the cerebrospinal fluid of Alzheimer's patients could mean that there is a decrease in the enzymes that metabolize this amino acid. One such enzyme is neuronal nitric oxide synthase (nNOS). In this study, neuronal nitric oxide synthase (nNOS), sourced from bovine brain was extracted and concentrated using two methods of precipitation: poly (ethylene glycol) 20 000 (PEG) and ammonium sulphate [(NH₄)₂S0₄). These two techniques gave no increase in yield nor fold purification and hence were abandoned in favour of ion exchange chromatography by DEAE-Sepharose. The enzyme was then successfully purified by anion-exchange and after dialysis produced a 38% yield and three fold purification and yielded the highest specific activity of 2.27 U/mg. Neuronal nitric oxide synthase (nNOS) was a heterodimeric protein with a total molecular mass of ± 225 kDa (95 and 130 kDa monomers). The temperature and pH optima of the enzyme were 40⁰C and 6.5, respectively. The kinetic parameters (KM and Vmax) of nNOS were 70 μM and 0.332 μmol.min⁻¹, respectively. Moreover neuronal nitric oxide synthase (nNOS) was relatively stable at 40⁰C (t½ = 3 h). It was also confirmed that β-amyloid peptides inhibited nNOS when bound to the enzyme and that nNOS behaved as a catalyst in fibril formation through association-dissociation between enzyme and β-amyloid peptide. It was further shown that Aβ₁₇₋₂₈ inhibited nNOS the most with a Ki of 1.92 μM and also had the highest Stern-Volmer value (Ksv) of 0.11 μM⁻¹ indicating tight binding affinity to nNOS and easier accessibility to fluor molecules during binding. Congo red, turbidity, thioflavin-T assays and transmission electron microscopy were successfully used to detect and visualize the presence of fibrils by studying the process of fibrillogenesis. Computerized molecular modeling successfully studied protein dynamics and conformational changes of nNOS. These results correlated with resonance energy transfer (FRET) results which revealed the distance of tryptophan residues from the arginine bound at enzyme active site. Both the aforementioned techniques revealed that in the natural state of the enzyme with arginine bound at the active site, the tryptophan residues (TRP₆₂₅ and TRP₇₂₁) were positioned at the surface of the enzyme 28 Å away from the active site. When the amyloid peptide (Aβ₁₇₋₂₈) was bound to the active site, these same two amino acids moved 14 Å closer to the active site. A five residue hydrophobic fragment Aβ₁₇₋₂₁ [Leu₁₇ - Val₁₈ - Phe₁₉ - Phe₂₀ - Ala₁] within Aβ₁₇₋₂₈ was shown by computer modeling to be critical to the binding of the peptide to the active site of nNOS.
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Non-perturbative unitarity constraints on the ratio of shear viscosity to entropy density in ultraviolet-complete theories with a gravity dual
- Brustein, Ram, Medved, Allan J M
- Authors: Brustein, Ram , Medved, Allan J M
- Date: 2011
- Language: English
- Type: text , Article
- Identifier: vital:6817 , http://hdl.handle.net/10962/d1004327
- Description: We reconsider, from a novel perspective, how unitarity constrains the corrections to the ratio of shear viscosity η to entropy density s. We start with higher-derivative extensions of Einstein gravity in asymptotically anti-de Sitter spacetimes. It is assumed that these theories are derived from string theory and thus have a unitary UV completion that is dual to a unitary, UV-complete boundary gauge theory. We then propose that the gravitational perturbations about a solution of the UV-complete theory are described by an effective theory whose linearized equations of motion have at most two time derivatives. Our proposal leads to a concrete prescription for the calculation of η/s for theories of gravity with arbitrary higher-derivative corrections. The resulting ratio can take on values above or below 1/4π and is consistent with all the previous calculations, even though our reasoning is substantially different. For the purpose of calculating η/s, our proposal also leads to only two possible candidates for the effective two-derivative theory: Einstein and Gauss-Bonnet gravity. The distinction between the two is that Einstein gravity satisfies the equivalence principle, and so its graviton correlation functions are polarization-independent, whereas the Gauss-Bonnet theory has polarization-dependent correlation functions. We discuss the graviton three-point functions in this context and explain how these can provide additional information on the value of η/s.
- Full Text:
- Authors: Brustein, Ram , Medved, Allan J M
- Date: 2011
- Language: English
- Type: text , Article
- Identifier: vital:6817 , http://hdl.handle.net/10962/d1004327
- Description: We reconsider, from a novel perspective, how unitarity constrains the corrections to the ratio of shear viscosity η to entropy density s. We start with higher-derivative extensions of Einstein gravity in asymptotically anti-de Sitter spacetimes. It is assumed that these theories are derived from string theory and thus have a unitary UV completion that is dual to a unitary, UV-complete boundary gauge theory. We then propose that the gravitational perturbations about a solution of the UV-complete theory are described by an effective theory whose linearized equations of motion have at most two time derivatives. Our proposal leads to a concrete prescription for the calculation of η/s for theories of gravity with arbitrary higher-derivative corrections. The resulting ratio can take on values above or below 1/4π and is consistent with all the previous calculations, even though our reasoning is substantially different. For the purpose of calculating η/s, our proposal also leads to only two possible candidates for the effective two-derivative theory: Einstein and Gauss-Bonnet gravity. The distinction between the two is that Einstein gravity satisfies the equivalence principle, and so its graviton correlation functions are polarization-independent, whereas the Gauss-Bonnet theory has polarization-dependent correlation functions. We discuss the graviton three-point functions in this context and explain how these can provide additional information on the value of η/s.
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Oil enclave economy and sexual liaisons in Nigeria's Niger Delta region
- Authors: Gandu, Yohanna Kagoro
- Date: 2011
- Subjects: Women -- Violence against -- Nigeria Abused women -- Nigeria Sexual abuse victims -- Nigeria Prostitution -- Nigeria Oil industries -- Nigeria
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3318 , http://hdl.handle.net/10962/d1003106
- Description: This thesis examines the intersection of oil enclave economy and the phenomenon of sexual liaisons in Nigeria’s Niger Delta region. The particular focus of this thesis is on the extent to which oil enclavity contributes to the emergence of sexual liaisons between local women and expatriate oil workers. Despite the fact that the Nigerian oil industry has been subjected to considerable scholarly debate for over five decades, this aspect of the social dimension of oil has not received adequate scholarly attention. Gender-specific discourse has tended to focus more on women protest. Other aspects, such as gender-specific violence that women in the region have had to live with, are either ignored or poorly articulated. Picketing of oil platforms by protesting women is celebrated as signs that women are active in the struggle against oil Transnational Companies (TNCs). While women protest is a significant struggle against oil TNCs, it has the potential of blurring our intellectual focus on the specific challenges confronting women in the Niger Delta. This study shows that since the inauguration of the Willink Commission in 1957, national palliatives meant to alleviate poverty in the Niger Delta region have not been gender sensitive. A review of the 1957 Willink Commission and others that came after it shows that the Nigerian state is yet to address the peculiar problems that the oil industry has brought to the women folk in the region. The paradox is that while oil provides enormous wealth and means of patronage to the Nigerian state elite, the oil TNCs, and better paid expatriate oil workers, a large section of the local Oil Bearing Communities (OBCs), especially women and unemployed youth, are not only dispossessed but survive in an environment characterised by anxiety and misery. With limited survival alternatives, youths resort to violent protest including oil thefts and bunkering. Local women are also immersed in this debacle because some of them resort to sexual liaisons with economically empowered expatriate oil workers as an alternative means of survival. This study therefore shifts the focus to women by exploring the extent to which sexual liaison reflects the contradictions in the enclave oil economy. The study employed an enclave economy conceptual framework to demonstrate that oil extractive activities compromise and distort the local economies of OBCs. This situation compels local women to seek for alternative means of survival by entering into sexual liaisons with more financially privileged expatriate oil workers. The study reviewed relevant secondary documentary sources of data. Further, it employed primary data collection techniques which include in-depth interviews/life histories, ethnographic observations, focus group discussions, and visual sociology. Besides obtaining the social profile and challenges facing the women involved in sexual liaisons with expatriate oil workers, the study provides an outline of participants’ narratives on the different social and economic dimensions of the intersection of oil enclave economy and sexual liaisons. The study found that some of the women involved in sexual liaisons with expatriate oil workers have been abandoned with ‘fatherless’ children. Some of them have also been rejected by their immediate family members and, in some cases, by their community. The study also found that the phenomenon of sexual liaisons and the incidents of abandoned ‘fatherless’ children that result from the practice, has over the years been played out through local resentment against oil TNCs and their expatriate employees. This finding helps to fill the gap in narratives and to make sense of the civic revolt and deepening instability in the Niger Delta region.
- Full Text:
- Authors: Gandu, Yohanna Kagoro
- Date: 2011
- Subjects: Women -- Violence against -- Nigeria Abused women -- Nigeria Sexual abuse victims -- Nigeria Prostitution -- Nigeria Oil industries -- Nigeria
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3318 , http://hdl.handle.net/10962/d1003106
- Description: This thesis examines the intersection of oil enclave economy and the phenomenon of sexual liaisons in Nigeria’s Niger Delta region. The particular focus of this thesis is on the extent to which oil enclavity contributes to the emergence of sexual liaisons between local women and expatriate oil workers. Despite the fact that the Nigerian oil industry has been subjected to considerable scholarly debate for over five decades, this aspect of the social dimension of oil has not received adequate scholarly attention. Gender-specific discourse has tended to focus more on women protest. Other aspects, such as gender-specific violence that women in the region have had to live with, are either ignored or poorly articulated. Picketing of oil platforms by protesting women is celebrated as signs that women are active in the struggle against oil Transnational Companies (TNCs). While women protest is a significant struggle against oil TNCs, it has the potential of blurring our intellectual focus on the specific challenges confronting women in the Niger Delta. This study shows that since the inauguration of the Willink Commission in 1957, national palliatives meant to alleviate poverty in the Niger Delta region have not been gender sensitive. A review of the 1957 Willink Commission and others that came after it shows that the Nigerian state is yet to address the peculiar problems that the oil industry has brought to the women folk in the region. The paradox is that while oil provides enormous wealth and means of patronage to the Nigerian state elite, the oil TNCs, and better paid expatriate oil workers, a large section of the local Oil Bearing Communities (OBCs), especially women and unemployed youth, are not only dispossessed but survive in an environment characterised by anxiety and misery. With limited survival alternatives, youths resort to violent protest including oil thefts and bunkering. Local women are also immersed in this debacle because some of them resort to sexual liaisons with economically empowered expatriate oil workers as an alternative means of survival. This study therefore shifts the focus to women by exploring the extent to which sexual liaison reflects the contradictions in the enclave oil economy. The study employed an enclave economy conceptual framework to demonstrate that oil extractive activities compromise and distort the local economies of OBCs. This situation compels local women to seek for alternative means of survival by entering into sexual liaisons with more financially privileged expatriate oil workers. The study reviewed relevant secondary documentary sources of data. Further, it employed primary data collection techniques which include in-depth interviews/life histories, ethnographic observations, focus group discussions, and visual sociology. Besides obtaining the social profile and challenges facing the women involved in sexual liaisons with expatriate oil workers, the study provides an outline of participants’ narratives on the different social and economic dimensions of the intersection of oil enclave economy and sexual liaisons. The study found that some of the women involved in sexual liaisons with expatriate oil workers have been abandoned with ‘fatherless’ children. Some of them have also been rejected by their immediate family members and, in some cases, by their community. The study also found that the phenomenon of sexual liaisons and the incidents of abandoned ‘fatherless’ children that result from the practice, has over the years been played out through local resentment against oil TNCs and their expatriate employees. This finding helps to fill the gap in narratives and to make sense of the civic revolt and deepening instability in the Niger Delta region.
- Full Text:
On His Blindness
- Authors: Wylie, Dan
- Date: 2011
- Subjects: To be catalogued
- Language: English
- Type: text , poem
- Identifier: http://hdl.handle.net/10962/468730 , vital:77119 , ISBN 0028-4459 , https://journals.co.za/doi/epdf/10.10520/EJC125847
- Description: New Coin is one of South Africa's most established and influential poetry journals. It publishes poetry, and poetry-related reviews, commentary and interviews. New Coin places a particular emphasis on evolving forms and experimental use of the English language in poetry in the South African context. In this sense it has traced the most exciting trends and currents in contemporary poetry in South Africa for a decade of more. The journal is published twice a year in June and December by the Institute for the Study of English in Africa (ISEA), Rhodes University.
- Full Text:
- Authors: Wylie, Dan
- Date: 2011
- Subjects: To be catalogued
- Language: English
- Type: text , poem
- Identifier: http://hdl.handle.net/10962/468730 , vital:77119 , ISBN 0028-4459 , https://journals.co.za/doi/epdf/10.10520/EJC125847
- Description: New Coin is one of South Africa's most established and influential poetry journals. It publishes poetry, and poetry-related reviews, commentary and interviews. New Coin places a particular emphasis on evolving forms and experimental use of the English language in poetry in the South African context. In this sense it has traced the most exciting trends and currents in contemporary poetry in South Africa for a decade of more. The journal is published twice a year in June and December by the Institute for the Study of English in Africa (ISEA), Rhodes University.
- Full Text:
Ontogenetic dietary shift and morphological correlates for Diplodus capensis (Teleostei Sparidae) in southern Angola
- Richardson, Timothy J, Potts, Warren M, Santos, Carmen V D, Sauer, Warwick H H
- Authors: Richardson, Timothy J , Potts, Warren M , Santos, Carmen V D , Sauer, Warwick H H
- Date: 2011
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/443984 , vital:74176 , https://doi.org/10.1080/15627020.2011.11407501
- Description: Allometric growth patterns of functional morphological variables that reflect resource use in fish were correlated with the diet of Diplodus capensis in southern Angola. A total of 114 individuals (76–336 mm FL) were collected for stomach content analysis and a further 35 individuals (80–320 mm FL) for morphometric analysis. The major dietary components belonged to the groups Chlorophyta, Cirripedia, Rhodophyta and Bivalvia, and made up 71.7% of the diet in terms of a computed ranking index. There was a clear ontogenetic dietary shift with small fish feeding predominantly on algae and large fish on barnacles and mussels. This increasingly durophagous diet corresponded with a positive allometric growth pattern in the gape dimensions (width, height and surface area), adductor mandibulae muscle process and incisor width. Conversely, the relative gut length followed an isometric growth pattern, suggesting a decreased absorptive capacity. This isometric growth pattern is attributed to the better digestibility of the durophagous prey items when compared with algae and further corroborates a link between the morphology and an ontogenetic dietary shift observed in this species.
- Full Text:
- Authors: Richardson, Timothy J , Potts, Warren M , Santos, Carmen V D , Sauer, Warwick H H
- Date: 2011
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/443984 , vital:74176 , https://doi.org/10.1080/15627020.2011.11407501
- Description: Allometric growth patterns of functional morphological variables that reflect resource use in fish were correlated with the diet of Diplodus capensis in southern Angola. A total of 114 individuals (76–336 mm FL) were collected for stomach content analysis and a further 35 individuals (80–320 mm FL) for morphometric analysis. The major dietary components belonged to the groups Chlorophyta, Cirripedia, Rhodophyta and Bivalvia, and made up 71.7% of the diet in terms of a computed ranking index. There was a clear ontogenetic dietary shift with small fish feeding predominantly on algae and large fish on barnacles and mussels. This increasingly durophagous diet corresponded with a positive allometric growth pattern in the gape dimensions (width, height and surface area), adductor mandibulae muscle process and incisor width. Conversely, the relative gut length followed an isometric growth pattern, suggesting a decreased absorptive capacity. This isometric growth pattern is attributed to the better digestibility of the durophagous prey items when compared with algae and further corroborates a link between the morphology and an ontogenetic dietary shift observed in this species.
- Full Text:
Opportunity and connectivity : selecting land managers for involvement in a conservation corridor linking two protected areas in the Langkloof Valley, South Africa
- Authors: McClure, Alice
- Date: 2011
- Subjects: Corridors (Ecology) -- South Africa -- Eastern Cape , National parks and reserves -- South Africa , Landscape ecology -- South Africa , Wildlife conservation -- South Africa , Conservation of natural resources -- South Africa , Land use -- South Africa -- Planning
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4770 , http://hdl.handle.net/10962/d1007590 , Corridors (Ecology) -- South Africa -- Eastern Cape , National parks and reserves -- South Africa , Landscape ecology -- South Africa , Wildlife conservation -- South Africa , Conservation of natural resources -- South Africa , Land use -- South Africa -- Planning
- Description: The Eden To Addo Corridor Initiative aims to connect formally protected areas in a conservation corridor from the coastal area of the Eden District near Plettenberg Bay, Western Cape, South Africa to the Addo National Elephant Park, Eastern Cape, South Africa. The corridor will incorporate government and privately owned land, and will be an attempt to maintain ecological processes at a range of spatial and temporal scales. The Langkloof Valley lies between the Baviaanskloof World Heritage Area and the Tstitsikamma National Park; two formally protected areas that will be incorporated into the Eden To Addo Corridor. Spatial prioritization analyses allow conservation planners to select areas that should be targeted for conservation action based on a range of criteria. Historically, ecological criteria have been included mostly alone in spatial prioritization. Recently, the idea of ‘conservation opportunity’ has emerged in the field of conservation planning; the notion suggests that a range of different types of data should be included in processes to spatially prioritise for conservation. By including those data defined as ‘human’ and ‘social’ data into prioritising activities, the feasibility of conservation plans can be accounted for, but historically conservation planners have failed to do so. I conducted a literature review that demonstrated that although the importance of human and social data are acknowledged in the conservation planning literature, these data that define opportunity are rarely actually included in spatial prioritisation analyses. I then carried out a social assessment that allowed me to define the social and human context of our study area and, specifically, what stewardship instruments land managers in the Langkloof would be prepared to engage. We found that land managers were generally willing to engage, but lacked the financial capacity to adopt conservation methods. Using a subset of the social and human data that were collected in the social assessment, I trialled a new Decision Support Software to fuse those data with ecological data in a novel attempt to identify priority areas for conservation action based on ecological integrity and feasibility. We also scheduled (ranked) land managers to approach for conservation action with a focus on local champions and clusters of land managers displaying strong conservation characteristics. Two corridors were identified; a major corridor in the western region of the valley and a secondary corridor closer to the middle. The members of the Initiative have been briefed on the outcomes, which provided them an opportunity to provide feedback; it is hoped that the framework of this study can be used for planning future connections. The Eden To Addo Corridor Initiative sent out a stewardship extension officer in February 2011 to approach those land managers areas that were identified. This planning exercise is a good demonstration of how, by collaborating effectively, academic conservation planners can contribute to supporting decision making by organizations that are implementing conservation action.
- Full Text:
- Authors: McClure, Alice
- Date: 2011
- Subjects: Corridors (Ecology) -- South Africa -- Eastern Cape , National parks and reserves -- South Africa , Landscape ecology -- South Africa , Wildlife conservation -- South Africa , Conservation of natural resources -- South Africa , Land use -- South Africa -- Planning
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4770 , http://hdl.handle.net/10962/d1007590 , Corridors (Ecology) -- South Africa -- Eastern Cape , National parks and reserves -- South Africa , Landscape ecology -- South Africa , Wildlife conservation -- South Africa , Conservation of natural resources -- South Africa , Land use -- South Africa -- Planning
- Description: The Eden To Addo Corridor Initiative aims to connect formally protected areas in a conservation corridor from the coastal area of the Eden District near Plettenberg Bay, Western Cape, South Africa to the Addo National Elephant Park, Eastern Cape, South Africa. The corridor will incorporate government and privately owned land, and will be an attempt to maintain ecological processes at a range of spatial and temporal scales. The Langkloof Valley lies between the Baviaanskloof World Heritage Area and the Tstitsikamma National Park; two formally protected areas that will be incorporated into the Eden To Addo Corridor. Spatial prioritization analyses allow conservation planners to select areas that should be targeted for conservation action based on a range of criteria. Historically, ecological criteria have been included mostly alone in spatial prioritization. Recently, the idea of ‘conservation opportunity’ has emerged in the field of conservation planning; the notion suggests that a range of different types of data should be included in processes to spatially prioritise for conservation. By including those data defined as ‘human’ and ‘social’ data into prioritising activities, the feasibility of conservation plans can be accounted for, but historically conservation planners have failed to do so. I conducted a literature review that demonstrated that although the importance of human and social data are acknowledged in the conservation planning literature, these data that define opportunity are rarely actually included in spatial prioritisation analyses. I then carried out a social assessment that allowed me to define the social and human context of our study area and, specifically, what stewardship instruments land managers in the Langkloof would be prepared to engage. We found that land managers were generally willing to engage, but lacked the financial capacity to adopt conservation methods. Using a subset of the social and human data that were collected in the social assessment, I trialled a new Decision Support Software to fuse those data with ecological data in a novel attempt to identify priority areas for conservation action based on ecological integrity and feasibility. We also scheduled (ranked) land managers to approach for conservation action with a focus on local champions and clusters of land managers displaying strong conservation characteristics. Two corridors were identified; a major corridor in the western region of the valley and a secondary corridor closer to the middle. The members of the Initiative have been briefed on the outcomes, which provided them an opportunity to provide feedback; it is hoped that the framework of this study can be used for planning future connections. The Eden To Addo Corridor Initiative sent out a stewardship extension officer in February 2011 to approach those land managers areas that were identified. This planning exercise is a good demonstration of how, by collaborating effectively, academic conservation planners can contribute to supporting decision making by organizations that are implementing conservation action.
- Full Text:
Optical limiting behavior of ring substituted zinc, indium and gallium phthalocyanines in the presence of quantum dots
- Britton, Jonathan, Litwinski, Christian, Durmus, Mahmut, Chauke, Vongani, Nyokong, Tebello
- Authors: Britton, Jonathan , Litwinski, Christian , Durmus, Mahmut , Chauke, Vongani , Nyokong, Tebello
- Date: 2011
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/247122 , vital:51548 , xlink:href="https://doi.org/10.1142/S1088424611004142"
- Description: This paper presents the study of the effects of CdTe-TGA quantum dots (QDs) on optical limiting ability of different phthalocyanine (Pc) complexes (1–10) containing Zn, Ga, In central metals and substituted with benzyloxyphenoxy, phenoxy, tert-butylphenoxy and amino groups. The optical limiting parameters of Pcs were higher for tert-butylphenoxy when compared to benzyloxyphenoxy and phenoxy substituents, in DMSO. Non-peripheral substitution decreased the optical limiting parameters. Third-order susceptibility (Im[χ(3)]/α) values of Pcs in the absence and presence of CdTe QDs were in the 10-12 to 10-10 esu.cm range. Hyperpolarizabilities (γ) ranged from 10-31 to 10-29 esu L for Pc alone or in mixture with QDs. There is a general improvement in optical limiting ability of Pc complexes in the presence of CdTe TGA QDs. Due to these promising results, future work can be implemented for the creation of Pc:QD thin films, which would then be examined to ensure that their optical limiting ability is still acceptable.
- Full Text:
- Authors: Britton, Jonathan , Litwinski, Christian , Durmus, Mahmut , Chauke, Vongani , Nyokong, Tebello
- Date: 2011
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/247122 , vital:51548 , xlink:href="https://doi.org/10.1142/S1088424611004142"
- Description: This paper presents the study of the effects of CdTe-TGA quantum dots (QDs) on optical limiting ability of different phthalocyanine (Pc) complexes (1–10) containing Zn, Ga, In central metals and substituted with benzyloxyphenoxy, phenoxy, tert-butylphenoxy and amino groups. The optical limiting parameters of Pcs were higher for tert-butylphenoxy when compared to benzyloxyphenoxy and phenoxy substituents, in DMSO. Non-peripheral substitution decreased the optical limiting parameters. Third-order susceptibility (Im[χ(3)]/α) values of Pcs in the absence and presence of CdTe QDs were in the 10-12 to 10-10 esu.cm range. Hyperpolarizabilities (γ) ranged from 10-31 to 10-29 esu L for Pc alone or in mixture with QDs. There is a general improvement in optical limiting ability of Pc complexes in the presence of CdTe TGA QDs. Due to these promising results, future work can be implemented for the creation of Pc:QD thin films, which would then be examined to ensure that their optical limiting ability is still acceptable.
- Full Text:
Optimal template removal from molecularly imprinted polymers by pressurized hot water extraction
- Batlokwa, Bareki Shima, Mokgadi, Janes, Nyokong, Tebello, Torto, Nelson
- Authors: Batlokwa, Bareki Shima , Mokgadi, Janes , Nyokong, Tebello , Torto, Nelson
- Date: 2011
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/247813 , vital:51620 , xlink:href="https://doi.org/10.1007/s10337-010-1884-3"
- Description: An optimal extraction method for the removal of templates from molecularly imprinted polymers (MIPs) is presented. The extraction method is based on pressurized hot water extraction (PHWE). PHWE was evaluated by application to three distinctly colored MIPs for chlorophyll (green), quercetin (yellow) and phthalocynine (dark blue) with subsequent monitoring of template removal and template bleeding by an ultraviolet spectrophotometer. The templates were washed-off and the extraction efficiency (EE) was compared to that of soxhlet and ultrasonic extraction methods. PHWE employed hot water at an optimal temperature of 220 °C, pressure of 50 bars and flow rate of 2 mL min−1 to thoroughly wash-off the respective templates from their MIPs. The EE evaluated for PHWE was over 99.6% for all the MIPs with no subsequent or minimal template bleeding (more than 0.01%). The washing procedure was simple and relatively fast as it was achieved in 70 min at the most. At 95% confidence level (n = 3), soxhlet and ultrasonic recorded EE that was not significantly different (more than 94.5% in all cases) from that of PHWE (less than 99.6% in all cases). Soxhlet and ultrasonic had washing procedures that were slower (over 18 h) and employed large quantities (400 mL) of organic solvents modified with acids. The percentage relative standard deviations (%RSD) for the EE and recovery results were less than 2.3% in all cases indicating the high reproducibility of the method. Overall, the three methods performed comparably in extracting templates. PHWE seems to be the method of choice as it employed water which poses no environmental threat.
- Full Text:
- Authors: Batlokwa, Bareki Shima , Mokgadi, Janes , Nyokong, Tebello , Torto, Nelson
- Date: 2011
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/247813 , vital:51620 , xlink:href="https://doi.org/10.1007/s10337-010-1884-3"
- Description: An optimal extraction method for the removal of templates from molecularly imprinted polymers (MIPs) is presented. The extraction method is based on pressurized hot water extraction (PHWE). PHWE was evaluated by application to three distinctly colored MIPs for chlorophyll (green), quercetin (yellow) and phthalocynine (dark blue) with subsequent monitoring of template removal and template bleeding by an ultraviolet spectrophotometer. The templates were washed-off and the extraction efficiency (EE) was compared to that of soxhlet and ultrasonic extraction methods. PHWE employed hot water at an optimal temperature of 220 °C, pressure of 50 bars and flow rate of 2 mL min−1 to thoroughly wash-off the respective templates from their MIPs. The EE evaluated for PHWE was over 99.6% for all the MIPs with no subsequent or minimal template bleeding (more than 0.01%). The washing procedure was simple and relatively fast as it was achieved in 70 min at the most. At 95% confidence level (n = 3), soxhlet and ultrasonic recorded EE that was not significantly different (more than 94.5% in all cases) from that of PHWE (less than 99.6% in all cases). Soxhlet and ultrasonic had washing procedures that were slower (over 18 h) and employed large quantities (400 mL) of organic solvents modified with acids. The percentage relative standard deviations (%RSD) for the EE and recovery results were less than 2.3% in all cases indicating the high reproducibility of the method. Overall, the three methods performed comparably in extracting templates. PHWE seems to be the method of choice as it employed water which poses no environmental threat.
- Full Text:
Optimizing the electrocatalytic activity of surface confined Co macrocyclics for the electrooxidation of thiocyanate at pH 4
- Tshangana, Charmaine, Pavez, Jorge, Gulppi, Miguel A, De Mattos, Ivanildo Luiz, Arratia-Perez, Ramiro, Linares-Flores, Cristian, Paez, Maritza, Nyokong, Tebello, Zagal, José H
- Authors: Tshangana, Charmaine , Pavez, Jorge , Gulppi, Miguel A , De Mattos, Ivanildo Luiz , Arratia-Perez, Ramiro , Linares-Flores, Cristian , Paez, Maritza , Nyokong, Tebello , Zagal, José H
- Date: 2011
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/247726 , vital:51612 , xlink:href="https://doi.org/10.1002/elan.201000599"
- Description: We have studied the trends in catalytic activity of several Co macrocyclics confined on the surface graphite electrodes for the oxidation of thiocyanate. A plot of log i (at constant E) versus the formal potential of the catalyst gives a volcano correlation, indicating that the Co(II/I) redox potential needs to be tuned, in order to achieve maximum reactivity. Graphite electrodes modified with Co phthalocyanine at pH 4 exhibit linear amperometric response for thiocyanate concentration in the range 10−7 and 10−3 M. Theoretical calculations show that electrocatalytic activity (as log i at constant E) plotted versus the energy of the LUMO of the Co complex also gives a volcano correlation.
- Full Text:
- Authors: Tshangana, Charmaine , Pavez, Jorge , Gulppi, Miguel A , De Mattos, Ivanildo Luiz , Arratia-Perez, Ramiro , Linares-Flores, Cristian , Paez, Maritza , Nyokong, Tebello , Zagal, José H
- Date: 2011
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/247726 , vital:51612 , xlink:href="https://doi.org/10.1002/elan.201000599"
- Description: We have studied the trends in catalytic activity of several Co macrocyclics confined on the surface graphite electrodes for the oxidation of thiocyanate. A plot of log i (at constant E) versus the formal potential of the catalyst gives a volcano correlation, indicating that the Co(II/I) redox potential needs to be tuned, in order to achieve maximum reactivity. Graphite electrodes modified with Co phthalocyanine at pH 4 exhibit linear amperometric response for thiocyanate concentration in the range 10−7 and 10−3 M. Theoretical calculations show that electrocatalytic activity (as log i at constant E) plotted versus the energy of the LUMO of the Co complex also gives a volcano correlation.
- Full Text:
OVR : a novel architecture for voice-based applications
- Authors: Maema, Mathe
- Date: 2011 , 2011-04-01
- Subjects: Telephone systems -- Research , User interfaces (Computer systems) -- Research , Expert systems (Computer science) , Artificial intelligence , VoiceXML (Document markup language) , Application software -- Development
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4671 , http://hdl.handle.net/10962/d1006694 , Telephone systems -- Research , User interfaces (Computer systems) -- Research , Expert systems (Computer science) , Artificial intelligence , VoiceXML (Document markup language) , Application software -- Development
- Description: Despite the inherent limitation of accessing information serially, voice applications are increasingly growing in popularity as computing technologies advance. This is a positive development, because voice communication offers a number of benefits over other forms of communication. For example, voice may be better for delivering services to users whose eyes and hands may be engaged in other activities (e.g. driving) or to semi-literate or illiterate users. This thesis proposes a knowledge based architecture for building voice applications to help reduce the limitations of serial access to information. The proposed architecture, called OVR (Ontologies, VoiceXML and Reasoners), uses a rich backend that represents knowledge via ontologies and utilises reasoning engines to reason with it, in order to generate intelligent behaviour. Ontologies were chosen over other knowledge representation formalisms because of their expressivity and executable format, and because current trends suggest a general shift towards the use of ontologies in many systems used for information storing and sharing. For the frontend, this architecture uses VoiceXML, the emerging, and de facto standard for voice automated applications. A functional prototype was built for an initial validation of the architecture. The system is a simple voice application to help locate information about service providers that offer HIV (Human Immunodeficiency Virus) testing. We called this implementation HTLS (HIV Testing Locator System). The functional prototype was implemented using a number of technologies. OWL API, a Java interface designed to facilitate manipulation of ontologies authored in OWL was used to build a customised query interface for HTLS. Pellet reasoner was used for supporting queries to the knowledge base and Drools (JBoss rule engine) was used for processing dialog rules. VXI was used as the VoiceXML browser and an experimental softswitch called iLanga as the bridge to the telephony system. (At the heart of iLanga is Asterisk, a well known PBX-in-a-box.) HTLS behaved properly under system testing, providing the sought initial validation of OVR. , LaTeX with hyperref package
- Full Text:
- Authors: Maema, Mathe
- Date: 2011 , 2011-04-01
- Subjects: Telephone systems -- Research , User interfaces (Computer systems) -- Research , Expert systems (Computer science) , Artificial intelligence , VoiceXML (Document markup language) , Application software -- Development
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4671 , http://hdl.handle.net/10962/d1006694 , Telephone systems -- Research , User interfaces (Computer systems) -- Research , Expert systems (Computer science) , Artificial intelligence , VoiceXML (Document markup language) , Application software -- Development
- Description: Despite the inherent limitation of accessing information serially, voice applications are increasingly growing in popularity as computing technologies advance. This is a positive development, because voice communication offers a number of benefits over other forms of communication. For example, voice may be better for delivering services to users whose eyes and hands may be engaged in other activities (e.g. driving) or to semi-literate or illiterate users. This thesis proposes a knowledge based architecture for building voice applications to help reduce the limitations of serial access to information. The proposed architecture, called OVR (Ontologies, VoiceXML and Reasoners), uses a rich backend that represents knowledge via ontologies and utilises reasoning engines to reason with it, in order to generate intelligent behaviour. Ontologies were chosen over other knowledge representation formalisms because of their expressivity and executable format, and because current trends suggest a general shift towards the use of ontologies in many systems used for information storing and sharing. For the frontend, this architecture uses VoiceXML, the emerging, and de facto standard for voice automated applications. A functional prototype was built for an initial validation of the architecture. The system is a simple voice application to help locate information about service providers that offer HIV (Human Immunodeficiency Virus) testing. We called this implementation HTLS (HIV Testing Locator System). The functional prototype was implemented using a number of technologies. OWL API, a Java interface designed to facilitate manipulation of ontologies authored in OWL was used to build a customised query interface for HTLS. Pellet reasoner was used for supporting queries to the knowledge base and Drools (JBoss rule engine) was used for processing dialog rules. VXI was used as the VoiceXML browser and an experimental softswitch called iLanga as the bridge to the telephony system. (At the heart of iLanga is Asterisk, a well known PBX-in-a-box.) HTLS behaved properly under system testing, providing the sought initial validation of OVR. , LaTeX with hyperref package
- Full Text:
Paper bridges: a critical examination of the Daily Dispatch's ‘community dialogues’
- Authors: Amner, Roderick J
- Date: 2011
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/142645 , vital:38098 , https://doi.org/10.1080/02560054.2011.545564
- Description: A series of town-hall-like meetings called the ‘community dialogues’ were conducted in 2009 by the Daily Dispatch newspaper in East London, under the banner of public/civic journalism, a global journalistic reform movement begun in the United States in the late 1980s. the editorial leadership of the newspaper imagined a number of core journalistic and civic purposes for the dialogues and succeeded in achieving some of these. However, the newspaper's claim that the dialogues could help to build ‘horizontal bridges’ between diverse communities in East London is critically examined through the example of two community dialogues which took place in neighbouring locations - the predominantly white, middle-class suburb of Beacon Bay, and the informal African settlement of Nompumelelo - on consecutive days in 2009. This article argues that social inequalities, particularly acute in the South African context, may preclude the emergence of a shared vision of the common good, and that joint deliberation between diverse social groups in the pursuit of consensus may not be realistic or even an appropriate goal, especially if it means ratifying an unjust status quo.
- Full Text:
- Authors: Amner, Roderick J
- Date: 2011
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/142645 , vital:38098 , https://doi.org/10.1080/02560054.2011.545564
- Description: A series of town-hall-like meetings called the ‘community dialogues’ were conducted in 2009 by the Daily Dispatch newspaper in East London, under the banner of public/civic journalism, a global journalistic reform movement begun in the United States in the late 1980s. the editorial leadership of the newspaper imagined a number of core journalistic and civic purposes for the dialogues and succeeded in achieving some of these. However, the newspaper's claim that the dialogues could help to build ‘horizontal bridges’ between diverse communities in East London is critically examined through the example of two community dialogues which took place in neighbouring locations - the predominantly white, middle-class suburb of Beacon Bay, and the informal African settlement of Nompumelelo - on consecutive days in 2009. This article argues that social inequalities, particularly acute in the South African context, may preclude the emergence of a shared vision of the common good, and that joint deliberation between diverse social groups in the pursuit of consensus may not be realistic or even an appropriate goal, especially if it means ratifying an unjust status quo.
- Full Text:
Pecuniary interests and the rule against adjudicative bias: the automatic disqualification or objective reasonable approach?
- Okpaluba, Chuks, Juma, Laurence
- Authors: Okpaluba, Chuks , Juma, Laurence
- Date: 2011
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/129093 , vital:36217 , https://hdl.handle.net/10520/EJC122974
- Description: This article deals with the issue of bias arising from pecuniary interest of a judge. Essentially, it asks the question: when does the pecuniary interest of a judge diminish his/her ability to apply his/her mind impartially to the dispute before him/her. To answer this question, the article undertakes a synthesis of the various rules and tests applied across Commonwealth jurisdictions and then compares them with the South African approach as outlined in two recent cases, namely Bernert v ABSA Bank Ltd 2011 (3) SA 92 (CC) and Ndimeni v Meeg Bank Ltd (Bank of Transkei) 2011 (1) SA 560 (SCA). Broadly, the article discusses the key aspects of the automatic disqualification approach preferred by the English courts, the Canadian objective reasonable approach and the realistic possibility approach recently adopted by the Australian courts. The article concludes that the South African approach that places emphasis on the objective reasonable test, complemented by the realistic possibility approach, may be most suitable, given the nature of complaints so far dealt with by the courts and the full propriety of the injunction in section 34 of the Constitution.
- Full Text: false
- Authors: Okpaluba, Chuks , Juma, Laurence
- Date: 2011
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/129093 , vital:36217 , https://hdl.handle.net/10520/EJC122974
- Description: This article deals with the issue of bias arising from pecuniary interest of a judge. Essentially, it asks the question: when does the pecuniary interest of a judge diminish his/her ability to apply his/her mind impartially to the dispute before him/her. To answer this question, the article undertakes a synthesis of the various rules and tests applied across Commonwealth jurisdictions and then compares them with the South African approach as outlined in two recent cases, namely Bernert v ABSA Bank Ltd 2011 (3) SA 92 (CC) and Ndimeni v Meeg Bank Ltd (Bank of Transkei) 2011 (1) SA 560 (SCA). Broadly, the article discusses the key aspects of the automatic disqualification approach preferred by the English courts, the Canadian objective reasonable approach and the realistic possibility approach recently adopted by the Australian courts. The article concludes that the South African approach that places emphasis on the objective reasonable test, complemented by the realistic possibility approach, may be most suitable, given the nature of complaints so far dealt with by the courts and the full propriety of the injunction in section 34 of the Constitution.
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Perceptions and constructions of cholera in the Eastern Province Herald and Daily Dispatch, 1980-2003
- Authors: Van Zyl, Kylie
- Date: 2011
- Subjects: Daily Dispatch (East London, South Africa) Eastern Province Herald (Port Elizabeth, South Africa) Journalism -- South Africa -- 20th century Journalism -- South Africa -- 21st century Cholera -- Reporting -- South Africa Epidemics -- Reporting -- South Africa Mass media -- Moral and ethical aspects -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2566 , http://hdl.handle.net/10962/d1002419
- Description: While the growing literature on South Africa’s healthcare and epidemics has often mentioned cholera in passing, there is as yet little academic work dedicated to it. This thesis addresses that deficit by examining the causes, spread and extent of cholera in South Africa between 1980 and 2003. Furthermore, it examines cholerarelated coverage in two newspapers, the Daily Dispatch and the Eastern Province Herald to determine how cholera and people with cholera were represented, and show how changes in the coverage of two major epidemics between 1980 and 2003 exemplify the political transition in South Africa, reflect changing political ideologies and reveal the shifting role of media within this period. The thesis argues three main points. Firstly, that representations of cholera and those who were sick with cholera were based on long-standing tropes connecting disease, class and ‘race’. Secondly, that policy-making based on these tropes influenced the unfair distribution and quality of health resources along racial lines, resulting in cholera outbreaks during the apartheid era. Failure to address these inequities post-apartheid, and the replacement of racial bias with discrimination on the grounds of socioeconomic development, resulted in further cholera outbreaks. Thirdly, using Alan Bell’s newspaper-discourse analysis framework to examine cholera-related articles the thesis compares and contrasts apartheid and postapartheid coverage in the two newspapers. This analysis reveals that during the 1980s the coverage was uncritical of the government’s handling of the epidemic or of its racially-discriminatory healthcare system. The newspapers uncritically accepted government-employed medical professionals as the final authorities on the epidemic, excluding alternative viewpoints. The coverage also “blamed the victim”, constructing affected “black” groups as potential threats to healthy “white” communities. Conversely, post–1994 coverage was criticised the government’s handling of the epidemic and the state of the public healthcare system. Government-employed medical professionals or spokespeople were not accepted as incontestable authorities and a range of sources were included. The coverage also shifted blame for the outbreaks to the government and its failure to address public health service delivery and rural development problems. The thesis shows the historical threat to the health of communities posed by uncaring governments.
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- Authors: Van Zyl, Kylie
- Date: 2011
- Subjects: Daily Dispatch (East London, South Africa) Eastern Province Herald (Port Elizabeth, South Africa) Journalism -- South Africa -- 20th century Journalism -- South Africa -- 21st century Cholera -- Reporting -- South Africa Epidemics -- Reporting -- South Africa Mass media -- Moral and ethical aspects -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2566 , http://hdl.handle.net/10962/d1002419
- Description: While the growing literature on South Africa’s healthcare and epidemics has often mentioned cholera in passing, there is as yet little academic work dedicated to it. This thesis addresses that deficit by examining the causes, spread and extent of cholera in South Africa between 1980 and 2003. Furthermore, it examines cholerarelated coverage in two newspapers, the Daily Dispatch and the Eastern Province Herald to determine how cholera and people with cholera were represented, and show how changes in the coverage of two major epidemics between 1980 and 2003 exemplify the political transition in South Africa, reflect changing political ideologies and reveal the shifting role of media within this period. The thesis argues three main points. Firstly, that representations of cholera and those who were sick with cholera were based on long-standing tropes connecting disease, class and ‘race’. Secondly, that policy-making based on these tropes influenced the unfair distribution and quality of health resources along racial lines, resulting in cholera outbreaks during the apartheid era. Failure to address these inequities post-apartheid, and the replacement of racial bias with discrimination on the grounds of socioeconomic development, resulted in further cholera outbreaks. Thirdly, using Alan Bell’s newspaper-discourse analysis framework to examine cholera-related articles the thesis compares and contrasts apartheid and postapartheid coverage in the two newspapers. This analysis reveals that during the 1980s the coverage was uncritical of the government’s handling of the epidemic or of its racially-discriminatory healthcare system. The newspapers uncritically accepted government-employed medical professionals as the final authorities on the epidemic, excluding alternative viewpoints. The coverage also “blamed the victim”, constructing affected “black” groups as potential threats to healthy “white” communities. Conversely, post–1994 coverage was criticised the government’s handling of the epidemic and the state of the public healthcare system. Government-employed medical professionals or spokespeople were not accepted as incontestable authorities and a range of sources were included. The coverage also shifted blame for the outbreaks to the government and its failure to address public health service delivery and rural development problems. The thesis shows the historical threat to the health of communities posed by uncaring governments.
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Perversity on paper taboo, abjection and literature: Iain Banks' The wasp factory, Ian McEwan's The cement garden, and Irvine Welsh's Marabou stork nightmares
- Authors: De Coning, Alexis
- Date: 2011
- Subjects: Banks, Iain, 1954-, The wasp factory Banks, Iain, 1954-, Criticism and interpretation McEwan, Ian -- The cement garden McEwan, Ian -- Criticism and interpretation Welsh, Irvine -- Marabou stork nightmares Welsh, Irvine -- Criticism and interpretation English literature -- 20th century -- History and criticism Taboo in literature Abjection in literature Kristeva, Julia, 1941-, Criticism and interpretation
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2205 , http://hdl.handle.net/10962/d1002247
- Description: This thesis explores the notion of perversity in literature, specifically with regard to representations of taboo and abjection in Iain Banks‟ The Wasp Factory, Ian McEwan‟s The Cement Garden, and Irvine Welsh‟s Marabou Stork Nightmares. Julia Kristeva‟s Powers of Horror: An Essay on Abjection, as well as her notion of revolt, constitute the central theoretical framework for my analysis. However, I also draw upon the concepts of monstrosity, grotesqueness and the uncanny in order to explicate the affect of abject fiction on the reader. I posit, then, that to engage with literary works that confront one with perversity, abjection and taboo entails exposing oneself to an ambiguous or liminal space in which culturally established values are both disrupted and affirmed. The subversive and revolutionary potential of the aforementioned novels is discussed with reference to the notion of the perverted Bildungsroman since, in their respective transgressions of taboos, the narrators of these novels disrupt social order, and their narratives end on a note of indeterminacy or the absolute finality of death, rather than self-actualisation. Moreover, in exposing the binaries of sex and gender as arbitrary and fluctuating, these narrators‟ perverse sexual and gender performativities gesture towards alternative modes of being (beyond social sanction), and invoke Kristeva‟s notion of individual revolt as a „condition necessary for the life of the mind and society‟.
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- Authors: De Coning, Alexis
- Date: 2011
- Subjects: Banks, Iain, 1954-, The wasp factory Banks, Iain, 1954-, Criticism and interpretation McEwan, Ian -- The cement garden McEwan, Ian -- Criticism and interpretation Welsh, Irvine -- Marabou stork nightmares Welsh, Irvine -- Criticism and interpretation English literature -- 20th century -- History and criticism Taboo in literature Abjection in literature Kristeva, Julia, 1941-, Criticism and interpretation
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2205 , http://hdl.handle.net/10962/d1002247
- Description: This thesis explores the notion of perversity in literature, specifically with regard to representations of taboo and abjection in Iain Banks‟ The Wasp Factory, Ian McEwan‟s The Cement Garden, and Irvine Welsh‟s Marabou Stork Nightmares. Julia Kristeva‟s Powers of Horror: An Essay on Abjection, as well as her notion of revolt, constitute the central theoretical framework for my analysis. However, I also draw upon the concepts of monstrosity, grotesqueness and the uncanny in order to explicate the affect of abject fiction on the reader. I posit, then, that to engage with literary works that confront one with perversity, abjection and taboo entails exposing oneself to an ambiguous or liminal space in which culturally established values are both disrupted and affirmed. The subversive and revolutionary potential of the aforementioned novels is discussed with reference to the notion of the perverted Bildungsroman since, in their respective transgressions of taboos, the narrators of these novels disrupt social order, and their narratives end on a note of indeterminacy or the absolute finality of death, rather than self-actualisation. Moreover, in exposing the binaries of sex and gender as arbitrary and fluctuating, these narrators‟ perverse sexual and gender performativities gesture towards alternative modes of being (beyond social sanction), and invoke Kristeva‟s notion of individual revolt as a „condition necessary for the life of the mind and society‟.
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Pet stores, aquarists and the internet trade as modes of introduction and spread of invasive macrophytes in South Africa
- Martin, Grant D, Coetzee, Julie A
- Authors: Martin, Grant D , Coetzee, Julie A
- Date: 2011
- Language: English
- Type: Article
- Identifier: vital:6843 , http://hdl.handle.net/10962/d1011045
- Description: Submerged aquatic invasive plant species are increasingly being recognised as a major threat to South African water ways. Pet stores, aquarists and the internet-mediated trade were investigated as pathways for submerged invasive macrophyte introductions into South Africa. Online and manually distributed surveys were used to determine the extent of movement of invasive as well as indigenous submerged plant species in South Africa. Sixty-four stores and twenty-three aquarists were surveyed. Four areas of risk were identified in this study. Firstly, and most importantly, a variety of invasive and/or prohibited plants are sold by pet stores. Secondly, there is a lack of knowledge regarding identification as well as regulation of submerged species, which may then result in the unintentional trade of potentially invasive species. It seems that, in many cases, the pet stores are ignorant or misinformed of the potential dangers, rather than intentionally attempting to breach the legislation. Thirdly, aquarists own, trade and move plants in and around the country, which makes it very difficult to monitor which species are being moved around South Africa and to what extent. Finally, the internet is a pathway of potential concern, but it is difficult to quantify its contribution to the trade of invasive species in South Africa.
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- Authors: Martin, Grant D , Coetzee, Julie A
- Date: 2011
- Language: English
- Type: Article
- Identifier: vital:6843 , http://hdl.handle.net/10962/d1011045
- Description: Submerged aquatic invasive plant species are increasingly being recognised as a major threat to South African water ways. Pet stores, aquarists and the internet-mediated trade were investigated as pathways for submerged invasive macrophyte introductions into South Africa. Online and manually distributed surveys were used to determine the extent of movement of invasive as well as indigenous submerged plant species in South Africa. Sixty-four stores and twenty-three aquarists were surveyed. Four areas of risk were identified in this study. Firstly, and most importantly, a variety of invasive and/or prohibited plants are sold by pet stores. Secondly, there is a lack of knowledge regarding identification as well as regulation of submerged species, which may then result in the unintentional trade of potentially invasive species. It seems that, in many cases, the pet stores are ignorant or misinformed of the potential dangers, rather than intentionally attempting to breach the legislation. Thirdly, aquarists own, trade and move plants in and around the country, which makes it very difficult to monitor which species are being moved around South Africa and to what extent. Finally, the internet is a pathway of potential concern, but it is difficult to quantify its contribution to the trade of invasive species in South Africa.
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