Influence of non-synonymous sequence mutations on the architecture of HIV-1 clade C protease receptor site : docking and molecular dynamics studies
- Authors: Onywera, David Harris
- Date: 2014
- Subjects: HIV (Viruses) -- Research , HIV infections -- Treatment -- Research , HIV infections -- Chemotherapy , Protease inhibitors -- Research , Viruses -- Effect of drugs on -- Research , Antiretroviral agents
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4116 , http://hdl.handle.net/10962/d1013133
- Description: Despite the current interventions to avert contagions and AIDS-related deaths, sub-Saharan Africa is still the region most severely affected by the HIV/AIDS pandemic, where clade C is the dominant circulating HIV-1 strain. The pol-encoded HIV-1 protease enzyme has been extensively exploited as a drug target. Protease inhibitors have been engineered within the framework of clade B, the commonest in America, Europe and Australia. Recent studies have attested the existence of sequence and catalytic disparities between clades B and C proteases that could upset drug susceptibilities. Emergence of drug-resistant associated mutations and combinatorial explosions due to recombination thwarts the attempt to stabilize the current highly active antiretroviral therapy (HAART) baseline. The project aimed at identifying the structural and molecular mechanisms hired by mutants to affect the efficacies of both FDA approved and Rhodes University (RU)-synthesized inhibitors, in order to define how current and or future drugs ought to be modified or synthesized with the intent of combating drug resistance. The rationale involved the generation of homology models of the HIV-1 sequences from the South African infants failing treatment with two protease inhibitors: lopinavir and ritonavir (as monitored by alterations in surrogate markers: CD4 cell count decline and viral load upsurge). Consistent with previous studies, we established nine polymorphisms: 12S, 15V, 19I, 36I, 41K, 63P, 69K, 89M, and 93L, linked to subtype C wild-type; some of which are associated with protease treatment in clade B. Even though we predicted two occurrence patterns of M46I, I54V and V82A mutations as V82A→I54V→M46I and I54V→V82A→M46V, other possibilities might exist. Mutations either caused a protracted or contracted active site cleft, which enforced differential drug responses. The in silico docking indicated susceptibility discordances between clades B and C in certain polymorphisms and non-polymorphisms. The RU-synthesized ligands displayed varied efficacies that were below those of the FDA approved protease inhibitors. The flaps underwent a wide range of structural motions to accommodate and stabilize the ligands. Computational analyses unravelled the need for these potential drugs to be restructured by (de novo) drug engineers to improve their binding fits, affinities, energies and interactions with multiple key protease residues in order to target resilient HIV-1 assemblages. Accumulating evidences on contrasting drug-choice interpretations from the Stanford HIVdb should act as an impetus for the customization of a HIVdb for the sub-Saharan subcontinent.
- Full Text:
- Authors: Onywera, David Harris
- Date: 2014
- Subjects: HIV (Viruses) -- Research , HIV infections -- Treatment -- Research , HIV infections -- Chemotherapy , Protease inhibitors -- Research , Viruses -- Effect of drugs on -- Research , Antiretroviral agents
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4116 , http://hdl.handle.net/10962/d1013133
- Description: Despite the current interventions to avert contagions and AIDS-related deaths, sub-Saharan Africa is still the region most severely affected by the HIV/AIDS pandemic, where clade C is the dominant circulating HIV-1 strain. The pol-encoded HIV-1 protease enzyme has been extensively exploited as a drug target. Protease inhibitors have been engineered within the framework of clade B, the commonest in America, Europe and Australia. Recent studies have attested the existence of sequence and catalytic disparities between clades B and C proteases that could upset drug susceptibilities. Emergence of drug-resistant associated mutations and combinatorial explosions due to recombination thwarts the attempt to stabilize the current highly active antiretroviral therapy (HAART) baseline. The project aimed at identifying the structural and molecular mechanisms hired by mutants to affect the efficacies of both FDA approved and Rhodes University (RU)-synthesized inhibitors, in order to define how current and or future drugs ought to be modified or synthesized with the intent of combating drug resistance. The rationale involved the generation of homology models of the HIV-1 sequences from the South African infants failing treatment with two protease inhibitors: lopinavir and ritonavir (as monitored by alterations in surrogate markers: CD4 cell count decline and viral load upsurge). Consistent with previous studies, we established nine polymorphisms: 12S, 15V, 19I, 36I, 41K, 63P, 69K, 89M, and 93L, linked to subtype C wild-type; some of which are associated with protease treatment in clade B. Even though we predicted two occurrence patterns of M46I, I54V and V82A mutations as V82A→I54V→M46I and I54V→V82A→M46V, other possibilities might exist. Mutations either caused a protracted or contracted active site cleft, which enforced differential drug responses. The in silico docking indicated susceptibility discordances between clades B and C in certain polymorphisms and non-polymorphisms. The RU-synthesized ligands displayed varied efficacies that were below those of the FDA approved protease inhibitors. The flaps underwent a wide range of structural motions to accommodate and stabilize the ligands. Computational analyses unravelled the need for these potential drugs to be restructured by (de novo) drug engineers to improve their binding fits, affinities, energies and interactions with multiple key protease residues in order to target resilient HIV-1 assemblages. Accumulating evidences on contrasting drug-choice interpretations from the Stanford HIVdb should act as an impetus for the customization of a HIVdb for the sub-Saharan subcontinent.
- Full Text:
Inside the river
- Authors: Buzani, Mangaliso Welcome
- Date: 2014
- Subjects: South African poetry (English) , Xhosa poetry
- Language: English , Xhosa
- Type: text , Thesis , Masters , MA
- Identifier: vital:5971
- Description: My collection is of imagistic associative poetry, influenced by Spanish and other kinds of modernism, and written in my two languages, isiXhosa and English. My approach to producing these poems is first via the mastery of sound, not on the actual meaning of a poem; working on the meaning would be the last stage. The language of each poem will be encountered as it comes down on the paper, leading me to the words meaningful for that particular poem.
- Full Text:
- Authors: Buzani, Mangaliso Welcome
- Date: 2014
- Subjects: South African poetry (English) , Xhosa poetry
- Language: English , Xhosa
- Type: text , Thesis , Masters , MA
- Identifier: vital:5971
- Description: My collection is of imagistic associative poetry, influenced by Spanish and other kinds of modernism, and written in my two languages, isiXhosa and English. My approach to producing these poems is first via the mastery of sound, not on the actual meaning of a poem; working on the meaning would be the last stage. The language of each poem will be encountered as it comes down on the paper, leading me to the words meaningful for that particular poem.
- Full Text:
Integrating customary practices and institutions into comanagement of small-scale fisheries:
- Kittinger, J N, Cinner, J E, Aswani, Shankar, White, A T
- Authors: Kittinger, J N , Cinner, J E , Aswani, Shankar , White, A T
- Date: 2014
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10962/178975 , vital:40099 , ISBN 9780520959606
- Description: This pioneering volume provides a blueprint for managing the challenges of ocean conservation using marine historical ecology—an interdisciplinary area of study that is helping society to gain a more in-depth understanding of past human-environmental interactions in coastal and marine ecosystems and of the ecological and social outcomes associated with these interactions. Developed by groundbreaking practitioners in the field, Marine Historical Ecology in Conservation highlights the innovative ways that historical ecology can be applied to improve conservation and management efforts in the oceans. The book focuses on four key challenges that confront marine conservation: (1) recovering endangered species, (2) conserving fisheries, (3) restoring ecosystems, and (4) engaging the public. Chapters emphasize real-world conservation scenarios appropriate for students, faculty, researchers, and practitioners in marine science, conservation biology, natural resource management, paleoecology, and marine and coastal archaeology. By focusing on success stories and applied solutions, this volume delivers the required up-to-date science and tools needed for restoration and protection of ocean and coastal ecosystems.
- Full Text:
- Authors: Kittinger, J N , Cinner, J E , Aswani, Shankar , White, A T
- Date: 2014
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10962/178975 , vital:40099 , ISBN 9780520959606
- Description: This pioneering volume provides a blueprint for managing the challenges of ocean conservation using marine historical ecology—an interdisciplinary area of study that is helping society to gain a more in-depth understanding of past human-environmental interactions in coastal and marine ecosystems and of the ecological and social outcomes associated with these interactions. Developed by groundbreaking practitioners in the field, Marine Historical Ecology in Conservation highlights the innovative ways that historical ecology can be applied to improve conservation and management efforts in the oceans. The book focuses on four key challenges that confront marine conservation: (1) recovering endangered species, (2) conserving fisheries, (3) restoring ecosystems, and (4) engaging the public. Chapters emphasize real-world conservation scenarios appropriate for students, faculty, researchers, and practitioners in marine science, conservation biology, natural resource management, paleoecology, and marine and coastal archaeology. By focusing on success stories and applied solutions, this volume delivers the required up-to-date science and tools needed for restoration and protection of ocean and coastal ecosystems.
- Full Text:
Inter-individual variability and phenotypic plasticity : the effect of the environment on the biogeography, population structure, ecophysiology and reproduction of the sandhoppers Talorchestia capensis and Africorchestia quadrispinosa
- Authors: Baldanzi, Simone
- Date: 2014
- Subjects: Phenotypic plasticity -- Research -- Africa, Southern Talitridae -- Research -- Africa, Southern Amphipoda -- Research -- Africa, Southern Climatic changes -- Environmental aspects -- Africa, Southern Marine biology -- Africa, Southern Adaptation (Biology) -- Africa, Southern
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5846 , http://hdl.handle.net/10962/d1011447
- Description: Climatic envelope models focus on the climatic variables affecting species or species assemblages, and are important tools to investigate the effect of climate change on their geographical ranges. These models have largely been proposed in order to make successful predictions on species‘ persistence, determining which variables are likely to induce range expansion, contraction, or shifting. More recent models, including the ability and the cost for individuals to respond promptly to an environmental stimulus, have revealed that species may express phenotypic plasticity able to induce adaptation to the new environment. Consequently, understanding how species evolve to a changing climate is fundamental. From this perspective, investigating intraspecific responses to an environmental variable may contribute to better understanding and prediction of the effect of climate change on the geographical range and evolution of species, particularly in the case of widespread species. In this context, the present study aimed at establishing how environmental variables (focussing mainly on temperature) may have contributed to shape the spatial distribution, physiology, reproductive biology and connectivity of two species of Southern African sandhoppers (Talorchestia capensis and Africorchestia quadrispinosa, Amphipoda, Talitridae). Most of the work was carried out on T. capensis, due to its widespread spatial distribution. A first investigation of the biogeography of T. capensis and A. quadrispinosa, revealed that, for both species, spatial patterns of abundance, size and sex ratio were not explained by the Abundant Centre Hypothesis (greater abundance at the core of a spatial range), but rather guided by bio-physical forces. Precisely, the abundance of sandhoppers was driven by the morphodynamic state of the beach, salinity and temperatures, with strong differentiation among sites that reflected local environmental conditions. In support of these findings, strong population structure in the genetics of T. capensis was found (three main groups) when investigating its phylogeography and genetic connectivity. Although such defined structure may suggests cryptic speciation, the concomitant within-population variation in the COX1 region of mtDNA, also highlighted the importance of individual genetic variability. High individual variability was also found in the response of T. capensis to temperature, both in its physiology (thermal plasticity) and its reproductive biology (maternal effects). Since temperature is one of the main variables affecting the coastal marine systems of southern Africa and the metabolism of animals in general, its effect on the physiology and reproduction of T. capensis was therefore investigated. Thermal responses to increasing/decreasing temperatures were assessed for separated populations of T. capensis. Individual variability was reported in the oxygen consumption of T. capensis in response to temperature (high variation around the means, especially for increasing temperatures). Among population differences in thermal sensitivity were significantly correlated with air temperature variability experienced over the past 23 years, highlighting the importance of historical temperature fluctuations to the current thermal physiology of these sandhoppers. Temperature also had an important effect on the reproductive plasticity of T. capensis. Different temperatures induced mothers to adjust the size of their offspring (i.e. egg size), with larger eggs produced at lower temperatures. Interestingly, females showed strongly significant among individual variation in the size of the eggs. Given the importance of understanding rapid responses of organisms to climate change and considering the fundamental role played by phenotypic plasticity in evolution, the overall study revealed the significance of individual plasticity and variability in response to the environment and highlighted its importance. Particularly, studying the thermal physiology of separated populations and understanding within population reproductive plasticity in response to temperature, helped to clarify how differences among individual responses have important consequences at the population level, possibly explaining the widespread distribution of T. capensis.
- Full Text:
- Authors: Baldanzi, Simone
- Date: 2014
- Subjects: Phenotypic plasticity -- Research -- Africa, Southern Talitridae -- Research -- Africa, Southern Amphipoda -- Research -- Africa, Southern Climatic changes -- Environmental aspects -- Africa, Southern Marine biology -- Africa, Southern Adaptation (Biology) -- Africa, Southern
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5846 , http://hdl.handle.net/10962/d1011447
- Description: Climatic envelope models focus on the climatic variables affecting species or species assemblages, and are important tools to investigate the effect of climate change on their geographical ranges. These models have largely been proposed in order to make successful predictions on species‘ persistence, determining which variables are likely to induce range expansion, contraction, or shifting. More recent models, including the ability and the cost for individuals to respond promptly to an environmental stimulus, have revealed that species may express phenotypic plasticity able to induce adaptation to the new environment. Consequently, understanding how species evolve to a changing climate is fundamental. From this perspective, investigating intraspecific responses to an environmental variable may contribute to better understanding and prediction of the effect of climate change on the geographical range and evolution of species, particularly in the case of widespread species. In this context, the present study aimed at establishing how environmental variables (focussing mainly on temperature) may have contributed to shape the spatial distribution, physiology, reproductive biology and connectivity of two species of Southern African sandhoppers (Talorchestia capensis and Africorchestia quadrispinosa, Amphipoda, Talitridae). Most of the work was carried out on T. capensis, due to its widespread spatial distribution. A first investigation of the biogeography of T. capensis and A. quadrispinosa, revealed that, for both species, spatial patterns of abundance, size and sex ratio were not explained by the Abundant Centre Hypothesis (greater abundance at the core of a spatial range), but rather guided by bio-physical forces. Precisely, the abundance of sandhoppers was driven by the morphodynamic state of the beach, salinity and temperatures, with strong differentiation among sites that reflected local environmental conditions. In support of these findings, strong population structure in the genetics of T. capensis was found (three main groups) when investigating its phylogeography and genetic connectivity. Although such defined structure may suggests cryptic speciation, the concomitant within-population variation in the COX1 region of mtDNA, also highlighted the importance of individual genetic variability. High individual variability was also found in the response of T. capensis to temperature, both in its physiology (thermal plasticity) and its reproductive biology (maternal effects). Since temperature is one of the main variables affecting the coastal marine systems of southern Africa and the metabolism of animals in general, its effect on the physiology and reproduction of T. capensis was therefore investigated. Thermal responses to increasing/decreasing temperatures were assessed for separated populations of T. capensis. Individual variability was reported in the oxygen consumption of T. capensis in response to temperature (high variation around the means, especially for increasing temperatures). Among population differences in thermal sensitivity were significantly correlated with air temperature variability experienced over the past 23 years, highlighting the importance of historical temperature fluctuations to the current thermal physiology of these sandhoppers. Temperature also had an important effect on the reproductive plasticity of T. capensis. Different temperatures induced mothers to adjust the size of their offspring (i.e. egg size), with larger eggs produced at lower temperatures. Interestingly, females showed strongly significant among individual variation in the size of the eggs. Given the importance of understanding rapid responses of organisms to climate change and considering the fundamental role played by phenotypic plasticity in evolution, the overall study revealed the significance of individual plasticity and variability in response to the environment and highlighted its importance. Particularly, studying the thermal physiology of separated populations and understanding within population reproductive plasticity in response to temperature, helped to clarify how differences among individual responses have important consequences at the population level, possibly explaining the widespread distribution of T. capensis.
- Full Text:
Interaction of multiple stressors: vulnerability, coping and adaptation within the context of climate change and HIV/AIDS in South Africa: Investigating strategies to strengthen livelihoods and food security and build resilience
- Hamer, Nicholas G, Shackleton, Sheona E
- Authors: Hamer, Nicholas G , Shackleton, Sheona E
- Date: 2014
- Subjects: Climatic changes -- Economic aspects -- Eastern Cape (South Africa) Climatic changes -- South Africa Climatic changes -- Social aspects -- South Africa
- Language: English
- Type: text
- Identifier: http://hdl.handle.net/10962/50065 , vital:25956
- Description: Government policy development and implementation is often designed to address different sectors of society in isolation, so social, economic and environmental issues are considered as being distinct from one other. Recently it has been acknowledged that 'working in silos' is not conducive for good governance and so efforts have been made for better co-ordination between different government departments and different spheres of government. Our research findings show the knock on effects of one problem into other areas of people's lives, highlighting why it is vital for policies and programmes to be far better co-ordinated. The different challenges and stresses that people face in their lives interact with one another in complex ways, undermining their capacity to cope with and adapt to future changes, such as those expected under climate change.
- Full Text:
- Authors: Hamer, Nicholas G , Shackleton, Sheona E
- Date: 2014
- Subjects: Climatic changes -- Economic aspects -- Eastern Cape (South Africa) Climatic changes -- South Africa Climatic changes -- Social aspects -- South Africa
- Language: English
- Type: text
- Identifier: http://hdl.handle.net/10962/50065 , vital:25956
- Description: Government policy development and implementation is often designed to address different sectors of society in isolation, so social, economic and environmental issues are considered as being distinct from one other. Recently it has been acknowledged that 'working in silos' is not conducive for good governance and so efforts have been made for better co-ordination between different government departments and different spheres of government. Our research findings show the knock on effects of one problem into other areas of people's lives, highlighting why it is vital for policies and programmes to be far better co-ordinated. The different challenges and stresses that people face in their lives interact with one another in complex ways, undermining their capacity to cope with and adapt to future changes, such as those expected under climate change.
- Full Text:
Interactive efficacies of Elephantorrhiza elephantina and Pentanisia prunelloides extracts and isolated compounds against gastrointestinal bacteria
- Mpofu, Smart J, Olivier, D K, Krause, Rui W M, Ndinteh, Derek T, Van Vuuren, S
- Authors: Mpofu, Smart J , Olivier, D K , Krause, Rui W M , Ndinteh, Derek T , Van Vuuren, S
- Date: 2014
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/124122 , vital:35552 , https://doi.org/10.1016/j.sajb.2014.07.002
- Description: Elephantorrhiza elephantina (Burch.) Skeels (Fabaceae) and Pentanisia prunelloides (Klotzsch ex Eckl. & Zeyh.) Walp. (Rubiaceae) are two medicinal plants used extensively in southern Africa to treat various ailments. Often, decoctions and infusions from these two plants are used in combination specifically for stomach ailments. The antimicrobial activities of the methanol and aqueous extracts of the rhizomes of the two plants, as well as the two active ingredients from the plants [(−)-epicatechin and palmitic acid] have been determined apart and in combination against Enterococcus faecalis (ATCC 29212), Escherichia coli (ATCC 8739) and Bacillus cereus (ATCC 11778). The minimum inhibitory concentration (MIC) values for the aqueous (0.50–16.00 mg/mL) and methanol (0.20–16.00 mg/mL) extracts independently demonstrated varied efficacies depending on the pathogen of study. When the two plants were combined in 1:1 ratios, synergistic to additive interactions (ΣFIC values 0.19–1.00) were noted. Efficacy for the two major compounds ranged between 0.13–0.63 mg/mL and mainly synergistic interactions were noted against E. faecalis and E. coli. The predominantly synergistic interactions noted between E. elephantina and P. prunelloides and major compounds, when tested in various ratios against these pathogens, provide some validation as to the traditional use of these two plants to treat bacterial gastrointestinal infections.
- Full Text:
- Authors: Mpofu, Smart J , Olivier, D K , Krause, Rui W M , Ndinteh, Derek T , Van Vuuren, S
- Date: 2014
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/124122 , vital:35552 , https://doi.org/10.1016/j.sajb.2014.07.002
- Description: Elephantorrhiza elephantina (Burch.) Skeels (Fabaceae) and Pentanisia prunelloides (Klotzsch ex Eckl. & Zeyh.) Walp. (Rubiaceae) are two medicinal plants used extensively in southern Africa to treat various ailments. Often, decoctions and infusions from these two plants are used in combination specifically for stomach ailments. The antimicrobial activities of the methanol and aqueous extracts of the rhizomes of the two plants, as well as the two active ingredients from the plants [(−)-epicatechin and palmitic acid] have been determined apart and in combination against Enterococcus faecalis (ATCC 29212), Escherichia coli (ATCC 8739) and Bacillus cereus (ATCC 11778). The minimum inhibitory concentration (MIC) values for the aqueous (0.50–16.00 mg/mL) and methanol (0.20–16.00 mg/mL) extracts independently demonstrated varied efficacies depending on the pathogen of study. When the two plants were combined in 1:1 ratios, synergistic to additive interactions (ΣFIC values 0.19–1.00) were noted. Efficacy for the two major compounds ranged between 0.13–0.63 mg/mL and mainly synergistic interactions were noted against E. faecalis and E. coli. The predominantly synergistic interactions noted between E. elephantina and P. prunelloides and major compounds, when tested in various ratios against these pathogens, provide some validation as to the traditional use of these two plants to treat bacterial gastrointestinal infections.
- Full Text:
Intimacy, sex and sexuality : the experiences of vertically-infected HIV-positive adolescents
- Authors: Smaill, Lindsay Ann
- Date: 2014
- Subjects: Teenagers -- Sexual behavior , HIV-positive youth -- South Africa -- Eastern Cape , HIV infections -- Social aspects -- South Africa -- Eastern Cape , HIV infections -- Transmission -- South Africa -- Eastern Cape , Teenagers -- Diseases -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3225 , http://hdl.handle.net/10962/d1013026
- Description: This research explores the lived experience of being a vertically or prenatally-infected HIV-positive adolescent. It looks specifically at how the participants experience intimacy, sex and sexuality. HIV/AIDS remains a global pandemic and vertically-infected adolescents are a growing new demographic. However, there is a poverty of research, and therefore interventions and support, for this demographic. This qualitative research conducted six individual, in-depth, semi-structured, psychoanalytic research interviews with three participants. The interviews were structured around projective drawings that the participants did in the course of each interview. The interviews were transcribed and analysed using psychodynamic object relations theory and organised through interpretative phenomenological analysis. Every effort was made to ensure that the research was conducted ethically and validly. The analysis found that the participants' experience of intimacy has resulted in a self that is constantly under threat. This in turn has negatively impacted on the participants' experience of sex and sexuality. The implication of this research is that more in-depth research needs to be done into this demographic so that better interventions and support may be offered.
- Full Text:
- Authors: Smaill, Lindsay Ann
- Date: 2014
- Subjects: Teenagers -- Sexual behavior , HIV-positive youth -- South Africa -- Eastern Cape , HIV infections -- Social aspects -- South Africa -- Eastern Cape , HIV infections -- Transmission -- South Africa -- Eastern Cape , Teenagers -- Diseases -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3225 , http://hdl.handle.net/10962/d1013026
- Description: This research explores the lived experience of being a vertically or prenatally-infected HIV-positive adolescent. It looks specifically at how the participants experience intimacy, sex and sexuality. HIV/AIDS remains a global pandemic and vertically-infected adolescents are a growing new demographic. However, there is a poverty of research, and therefore interventions and support, for this demographic. This qualitative research conducted six individual, in-depth, semi-structured, psychoanalytic research interviews with three participants. The interviews were structured around projective drawings that the participants did in the course of each interview. The interviews were transcribed and analysed using psychodynamic object relations theory and organised through interpretative phenomenological analysis. Every effort was made to ensure that the research was conducted ethically and validly. The analysis found that the participants' experience of intimacy has resulted in a self that is constantly under threat. This in turn has negatively impacted on the participants' experience of sex and sexuality. The implication of this research is that more in-depth research needs to be done into this demographic so that better interventions and support may be offered.
- Full Text:
Invariant optimal control on the three-dimensional semi-Euclidean group: control affine and quadratic Hamilton-Poisson systems
- Authors: Barrett, Dennis Ian
- Date: 2014
- Subjects: Automorphisms , Symmetry (Mathematics) , Lyapunov stability , Geometry, Riemannian , Geometry, Affine , Elliptic functions
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/64805 , vital:28605
- Description: In this thesis we consider invariant control systems and Hamilton-Poisson systems on the three dimensional semi-Euclidean group SE(1,1). We first classify the left-invariant control affine systems (under detached feedback equivalence). We provide a complete list of normal forms, as well as classifying conditions. As a corollary to this classification, we derive controllability criteria for control affine systems on SE(1,1). Secondly, we consider quadratic Hamilton-Poisson systems on the (minus) Lie-Poisson space se(1,1)*. These systems are classified up to an affine isomorphism. Six normal forms are identified for the homogeneous case, whereas sixteen representatives (including several infinite families) are obtained for the inhomogeneous systems. Thereafter we consider the stability and integration of the normal forms obtained. For all homogeneous systems, and a subclass of inhomogeneous systems, we perform a complete stability analysis and derive explicit expressions for all integral curves. (The extremal controls of a large class of optimal control problems on SE(1,1) are linearly related to these integral curves.) Lastly, we discuss the Riemannian and sub-Riemannian problems. The (left-invariant) Riemannian and sub-Riemannian structures on SE(1,1) are classified, up to isometric group automorphisms and scaling. Explicit expressions for the geodesics of the normalised structures are found.
- Full Text:
- Authors: Barrett, Dennis Ian
- Date: 2014
- Subjects: Automorphisms , Symmetry (Mathematics) , Lyapunov stability , Geometry, Riemannian , Geometry, Affine , Elliptic functions
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/64805 , vital:28605
- Description: In this thesis we consider invariant control systems and Hamilton-Poisson systems on the three dimensional semi-Euclidean group SE(1,1). We first classify the left-invariant control affine systems (under detached feedback equivalence). We provide a complete list of normal forms, as well as classifying conditions. As a corollary to this classification, we derive controllability criteria for control affine systems on SE(1,1). Secondly, we consider quadratic Hamilton-Poisson systems on the (minus) Lie-Poisson space se(1,1)*. These systems are classified up to an affine isomorphism. Six normal forms are identified for the homogeneous case, whereas sixteen representatives (including several infinite families) are obtained for the inhomogeneous systems. Thereafter we consider the stability and integration of the normal forms obtained. For all homogeneous systems, and a subclass of inhomogeneous systems, we perform a complete stability analysis and derive explicit expressions for all integral curves. (The extremal controls of a large class of optimal control problems on SE(1,1) are linearly related to these integral curves.) Lastly, we discuss the Riemannian and sub-Riemannian problems. The (left-invariant) Riemannian and sub-Riemannian structures on SE(1,1) are classified, up to isometric group automorphisms and scaling. Explicit expressions for the geodesics of the normalised structures are found.
- Full Text:
Invasive alien species as drivers in socio-ecological systems: Local adaptations towards use of Lantana in Southern India
- Kannan, Ramesh, Shackleton, Charlie M, Shaanker, Ramanan U
- Authors: Kannan, Ramesh , Shackleton, Charlie M , Shaanker, Ramanan U
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/180932 , vital:43671 , xlink:href="https://doi.org/10.1007/s10668-013-9500-y"
- Description: Lantana camara. L (hereafter Lantana) was first introduced by the British into India in 1807 as an ornamental plant. Since then the species has spread across the length and breadth of the country. Attempts to control Lantana in India have not been successful. In this study, we analysed the use of Lantana by local communities in southern India and identified the possible causes and consequences of its use through the use of a household survey of the socio-economic profile of the user and nonuser households and an analysis of the ecological history of the communities. Communities have been using Lantana for over 25–30 years and apparently such use was not prompted by external agencies. The characteristics of user and nonuser households were similar, except that Lantana users were more literate and had a greater number of occupations per household than nonusers. Per capita income was similar between user and nonuser groups. For nonuser groups, their main income sources were from trading (44 %), wage labour (32 %) and forest resources (23 %). In contrast, the Lantana user groups substituted their loss of income from forest resources (7 %) by income from Lantana (46 %). The ecological history revealed that Lantana was adopted as a resource at a time when it was increasing in the landscape and traditional bamboo resources were in decline because of overuse by commercial enterprises and mast flowering. This change in ecological resource availability prompted a major shift in livelihoods for some in the area.
- Full Text:
- Authors: Kannan, Ramesh , Shackleton, Charlie M , Shaanker, Ramanan U
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/180932 , vital:43671 , xlink:href="https://doi.org/10.1007/s10668-013-9500-y"
- Description: Lantana camara. L (hereafter Lantana) was first introduced by the British into India in 1807 as an ornamental plant. Since then the species has spread across the length and breadth of the country. Attempts to control Lantana in India have not been successful. In this study, we analysed the use of Lantana by local communities in southern India and identified the possible causes and consequences of its use through the use of a household survey of the socio-economic profile of the user and nonuser households and an analysis of the ecological history of the communities. Communities have been using Lantana for over 25–30 years and apparently such use was not prompted by external agencies. The characteristics of user and nonuser households were similar, except that Lantana users were more literate and had a greater number of occupations per household than nonusers. Per capita income was similar between user and nonuser groups. For nonuser groups, their main income sources were from trading (44 %), wage labour (32 %) and forest resources (23 %). In contrast, the Lantana user groups substituted their loss of income from forest resources (7 %) by income from Lantana (46 %). The ecological history revealed that Lantana was adopted as a resource at a time when it was increasing in the landscape and traditional bamboo resources were in decline because of overuse by commercial enterprises and mast flowering. This change in ecological resource availability prompted a major shift in livelihoods for some in the area.
- Full Text:
Investigating coral reef ethnobiology in the western Solomon Islands for enhancing livelihood resilience:
- Authors: Aswani, Shankar
- Date: 2014
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/145425 , vital:38437 , DOI: 10.15286/jps.123.3.237-276
- Description: Coral reefs are of great socio-economic and cultural importance for many coastal communities across the tropics, yet little is known about people's local classifications and their social and ecological relationships with these habitats. In the case of island peoples, coral reefs are more than just resource exploitation areas; they are also géomorphologie features that allow or bar people from navigating, markers that define property rights of the seascape in relation to other coastal and terrestrial habitats, and cultural and historical features that embody tribal identity and ideology. Building upon over two decades of research, this paper uses published and unpublished data to describe people's ecological and socio-economic relationships with coral reefs in two extensive lagoon ecosystems in the Western Solomon Islands.
- Full Text:
- Authors: Aswani, Shankar
- Date: 2014
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/145425 , vital:38437 , DOI: 10.15286/jps.123.3.237-276
- Description: Coral reefs are of great socio-economic and cultural importance for many coastal communities across the tropics, yet little is known about people's local classifications and their social and ecological relationships with these habitats. In the case of island peoples, coral reefs are more than just resource exploitation areas; they are also géomorphologie features that allow or bar people from navigating, markers that define property rights of the seascape in relation to other coastal and terrestrial habitats, and cultural and historical features that embody tribal identity and ideology. Building upon over two decades of research, this paper uses published and unpublished data to describe people's ecological and socio-economic relationships with coral reefs in two extensive lagoon ecosystems in the Western Solomon Islands.
- Full Text:
Investigating how problem solving skills can be developed using a collaborative learning environment
- Authors: Sonne, Anita
- Date: 2014
- Subjects: Mathematics -- Study and teaching (Elementary) -- South Africa , Social learning , Active learning , Problem solving in children , Educational equalization -- Research -- South Africa
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1977 , http://hdl.handle.net/10962/d1013017
- Description: This thesis examines whether problem solving strategies develop and improve through working in a collaborative environment and, if so, how. The study explored the way peer-topeer discussions which are focussed on finding solutions to mathematical problems might shape learners' attitudes and participation in mathematical problem solving. I use the Vygotskian (1978) socio-cultural perspective where the process of learning takes place within the Zone of Proximal Development (ZPD). Polya's problem solving heuristics (Polya, 1973) and Kilpatrick's "Instructional Triangle" (Kilpatrick, Swafford & Findell, 2001) provided the analytical framework for the study. Seven grade 7 learners from a Ex-Model C school, volunteered to participate in the study. The data gathering process involved an initial problem solving assessment, a written questionnaire, observations and video recordings of the seven learners during a series of after school problem solving sessions and post intervention learner interviews. The study showed that group discussion can have a positive impact on learners' problem solving in several respects: My key findings point to: Mathematical communication does play a role in development of problem solving strategies. A more knowledgeable other, with regards to Vygotsky's (1978) ZPD and Kilpatrick et al's (2001) instructional triangle is a critical factor in the development of problem solving strategies. All five strands of Kilpatrick et al., (2001), strands for mathematical proficiency are required for correct solutions to be calculated. At times Polya's (1973) steps for problem solving move at a rapid pace and are difficult to notice. These steps develop at different speeds for different people.
- Full Text:
Investigating how problem solving skills can be developed using a collaborative learning environment
- Authors: Sonne, Anita
- Date: 2014
- Subjects: Mathematics -- Study and teaching (Elementary) -- South Africa , Social learning , Active learning , Problem solving in children , Educational equalization -- Research -- South Africa
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1977 , http://hdl.handle.net/10962/d1013017
- Description: This thesis examines whether problem solving strategies develop and improve through working in a collaborative environment and, if so, how. The study explored the way peer-topeer discussions which are focussed on finding solutions to mathematical problems might shape learners' attitudes and participation in mathematical problem solving. I use the Vygotskian (1978) socio-cultural perspective where the process of learning takes place within the Zone of Proximal Development (ZPD). Polya's problem solving heuristics (Polya, 1973) and Kilpatrick's "Instructional Triangle" (Kilpatrick, Swafford & Findell, 2001) provided the analytical framework for the study. Seven grade 7 learners from a Ex-Model C school, volunteered to participate in the study. The data gathering process involved an initial problem solving assessment, a written questionnaire, observations and video recordings of the seven learners during a series of after school problem solving sessions and post intervention learner interviews. The study showed that group discussion can have a positive impact on learners' problem solving in several respects: My key findings point to: Mathematical communication does play a role in development of problem solving strategies. A more knowledgeable other, with regards to Vygotsky's (1978) ZPD and Kilpatrick et al's (2001) instructional triangle is a critical factor in the development of problem solving strategies. All five strands of Kilpatrick et al., (2001), strands for mathematical proficiency are required for correct solutions to be calculated. At times Polya's (1973) steps for problem solving move at a rapid pace and are difficult to notice. These steps develop at different speeds for different people.
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Investigating the English vocabulary needs, exposure, and knowledge of isiXhosa speaking learners for transition from learning to read in the Foundation Phase to reading to learn in the Intermediate Phase : a case study
- Authors: Sibanda, Jabulani
- Date: 2014
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1968 , http://hdl.handle.net/10962/d1011790
- Description: The nature of learners' transition from Grade 3 to Grade 4 has serious and far reaching ramifications for their educational success in the subsequent grades. This is true of the South African education system, as it is for several other education contexts. The challenge that complicates the transition is largely a lexical one. It is with that understanding that the present study aimed to do three things namely: to determine the vocabulary needs of Grade 3 learners for transitioning to Grade 4; to establish the extent to which Grade 3 isiXhosa speaking learners are exposed to, and prepared for, the acquisition of that requisite vocabulary; and to establish the extent of Grade 4 learners' knowledge of that vocabulary at the beginning of the year. The vocabulary needs of Grade 3 learners for the transition to Grade 4 were determined from the Grade 4 subject textbook corpus. Word frequency was the criterion used to determine the usefulness and critical importance of a word for the transition. The AntConc concordance software program was used to generate word frequencies. Words with high frequency across the different subject areas, which were confirmed as high frequent in four other known word lists, were considered as constituting the vocabulary needs of learners at the verge of this significant transition. The extent of learners' preparedness for transitioning to Grade 4 in terms of their vocabulary exposure and vocabulary instruction was determined through teacher interviews, classroom observations, analysis of teacher classroom talk, analysis of the exposure and recycling of high frequent vocabulary in Grade 3 reading materials and classroom print. From these diverse sources, findings point to a paucity in both the exposure and recycling of the requisite vocabulary in these sources of classroom language input. Classroom observations and teacher interviews attest to lack of deliberate vocabulary instruction in the Grade 3 English First Additional Language lessons. The only extensive coverage of the requisite vocabulary was in the Grade 3 reading materials which included Big books, Readers and Workbooks. The Grade 4 learners' knowledge of the 60 high frequency words was tested through nine vocabulary tests, three of which tested their knowledge of word recognition, three tested passive word knowledge and the remaining three tested learners' active word knowledge. All the Grade 4 learners in the ten participating schools (297) were tested. Performance in the tests indicated that Grade 4 learners' knowledge of words requisite for reading to learn was low. That observation was consistent with an analysis of learners' performance per school, per district, per word, per test and per word bands. Tests of word recognition were done better than those of passive word knowledge and active word knowledge. Particularly problematic was test 4 which tested learners' knowledge of definition of words.
- Full Text:
- Authors: Sibanda, Jabulani
- Date: 2014
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1968 , http://hdl.handle.net/10962/d1011790
- Description: The nature of learners' transition from Grade 3 to Grade 4 has serious and far reaching ramifications for their educational success in the subsequent grades. This is true of the South African education system, as it is for several other education contexts. The challenge that complicates the transition is largely a lexical one. It is with that understanding that the present study aimed to do three things namely: to determine the vocabulary needs of Grade 3 learners for transitioning to Grade 4; to establish the extent to which Grade 3 isiXhosa speaking learners are exposed to, and prepared for, the acquisition of that requisite vocabulary; and to establish the extent of Grade 4 learners' knowledge of that vocabulary at the beginning of the year. The vocabulary needs of Grade 3 learners for the transition to Grade 4 were determined from the Grade 4 subject textbook corpus. Word frequency was the criterion used to determine the usefulness and critical importance of a word for the transition. The AntConc concordance software program was used to generate word frequencies. Words with high frequency across the different subject areas, which were confirmed as high frequent in four other known word lists, were considered as constituting the vocabulary needs of learners at the verge of this significant transition. The extent of learners' preparedness for transitioning to Grade 4 in terms of their vocabulary exposure and vocabulary instruction was determined through teacher interviews, classroom observations, analysis of teacher classroom talk, analysis of the exposure and recycling of high frequent vocabulary in Grade 3 reading materials and classroom print. From these diverse sources, findings point to a paucity in both the exposure and recycling of the requisite vocabulary in these sources of classroom language input. Classroom observations and teacher interviews attest to lack of deliberate vocabulary instruction in the Grade 3 English First Additional Language lessons. The only extensive coverage of the requisite vocabulary was in the Grade 3 reading materials which included Big books, Readers and Workbooks. The Grade 4 learners' knowledge of the 60 high frequency words was tested through nine vocabulary tests, three of which tested their knowledge of word recognition, three tested passive word knowledge and the remaining three tested learners' active word knowledge. All the Grade 4 learners in the ten participating schools (297) were tested. Performance in the tests indicated that Grade 4 learners' knowledge of words requisite for reading to learn was low. That observation was consistent with an analysis of learners' performance per school, per district, per word, per test and per word bands. Tests of word recognition were done better than those of passive word knowledge and active word knowledge. Particularly problematic was test 4 which tested learners' knowledge of definition of words.
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Investigating the role of mycorrhizal fungi and associated bacteria in promoting growth of citrus seedlings
- Authors: Sitole, Phumeza
- Date: 2014
- Subjects: Mycorrhizal fungi , Citrus -- South Africa , Citrus -- Diseases and pests -- Biological control -- South Africa , Fungi as biological pest control agents , Bacteria , Phytophthora , Pythium , Indoleacetic acid
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4111 , http://hdl.handle.net/10962/d1013033
- Description: South Africa is the world's second largest exporter of fresh citrus and is ranked 14th in citrus production. Fungal pathogens such as Phytophthora and Pythium cause economic losses as a result of root rot and brown rot. Mycorrhizal fungi are specialized members of the fungal community forming a mutualistic relationship with plant roots. Mycorrhizal fungal structures are known to associate with other soil microorganisms and these may contribute to improved plant growth. A diverse group of bacteria that interact with the mycorrhizal fungi are known as Mycorrhizal Helper Bacteria (MHB). The aim of this study was to investigate the role of arbuscular mycorrhiza and associated bacteria isolated from spores and determine whether they had any plant growth promoting potential. A total of 19 bacteria were isolated from arbuscular mycorrhizal spores and were molecularly identified as belonging to several Bacillus, Micrococcus, Onchrobactrum and Staphylococcus sp. All bacterial isolates were tested for plant growth promotion abilities. One Bacillus isolate was able to solubilise phosphate. Four isolates Micrococcus sp, Micrococcus leteus, Ochrobacterum sp and Ochrobacterum antropi were able to produce Indole Acetic Acid and three isolates showed potential to reduce growth of Phytophthora nicotianae, P. citrocola and P. citrophthora in in vitro plate cultures. Further tests using culture supernatants of the Bacillus sp, Micrococcus sp and Bacillus cereus confirmed their ability to inhibit or reduce growth of the three Phytophthora species in a 96 well bioassay. Bacillus sp and Bacillus cereus were able to inhibit Phytophthora spp by 95 to 100 % and Micrococcus spp was able to decrease pathogen growth by 60 to 94 %. These bacterial isolates were further evaluated for plant growth promoting abilities on citrus rough lemon seedlings alone or in combination with arbuscular mycorrhizal inoculum. Bacterial and mycorrhizal inoculants influence the increase in shoot and root biomass. Bacillus cereus in combination with mycorrhizal inoculum significantly increased seedling shoot to root ratio while root biomass was significantly increased with mycorrhizal inoculation. Due to the short duration of the trial mycorrhizal colonisation could not be assessed. It is evident that selected combinations of bacteria and mycorrhizal fungi could promote citrus seedling growth and potentially improve seedling health. Further studies under nursery conditions are recommended.
- Full Text:
- Authors: Sitole, Phumeza
- Date: 2014
- Subjects: Mycorrhizal fungi , Citrus -- South Africa , Citrus -- Diseases and pests -- Biological control -- South Africa , Fungi as biological pest control agents , Bacteria , Phytophthora , Pythium , Indoleacetic acid
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4111 , http://hdl.handle.net/10962/d1013033
- Description: South Africa is the world's second largest exporter of fresh citrus and is ranked 14th in citrus production. Fungal pathogens such as Phytophthora and Pythium cause economic losses as a result of root rot and brown rot. Mycorrhizal fungi are specialized members of the fungal community forming a mutualistic relationship with plant roots. Mycorrhizal fungal structures are known to associate with other soil microorganisms and these may contribute to improved plant growth. A diverse group of bacteria that interact with the mycorrhizal fungi are known as Mycorrhizal Helper Bacteria (MHB). The aim of this study was to investigate the role of arbuscular mycorrhiza and associated bacteria isolated from spores and determine whether they had any plant growth promoting potential. A total of 19 bacteria were isolated from arbuscular mycorrhizal spores and were molecularly identified as belonging to several Bacillus, Micrococcus, Onchrobactrum and Staphylococcus sp. All bacterial isolates were tested for plant growth promotion abilities. One Bacillus isolate was able to solubilise phosphate. Four isolates Micrococcus sp, Micrococcus leteus, Ochrobacterum sp and Ochrobacterum antropi were able to produce Indole Acetic Acid and three isolates showed potential to reduce growth of Phytophthora nicotianae, P. citrocola and P. citrophthora in in vitro plate cultures. Further tests using culture supernatants of the Bacillus sp, Micrococcus sp and Bacillus cereus confirmed their ability to inhibit or reduce growth of the three Phytophthora species in a 96 well bioassay. Bacillus sp and Bacillus cereus were able to inhibit Phytophthora spp by 95 to 100 % and Micrococcus spp was able to decrease pathogen growth by 60 to 94 %. These bacterial isolates were further evaluated for plant growth promoting abilities on citrus rough lemon seedlings alone or in combination with arbuscular mycorrhizal inoculum. Bacterial and mycorrhizal inoculants influence the increase in shoot and root biomass. Bacillus cereus in combination with mycorrhizal inoculum significantly increased seedling shoot to root ratio while root biomass was significantly increased with mycorrhizal inoculation. Due to the short duration of the trial mycorrhizal colonisation could not be assessed. It is evident that selected combinations of bacteria and mycorrhizal fungi could promote citrus seedling growth and potentially improve seedling health. Further studies under nursery conditions are recommended.
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Is economic growth without human development sustainable? : Sub-Saharan Africa’s recent growth acceleration in context
- Authors: Hadisi Basingene, Serge
- Date: 2014
- Subjects: Sustainable development -- Africa, Sub-Saharan , Economic development -- Africa, Sub-Saharan , Poverty -- Africa, Sub-Saharan , Africa, Sub-Saharan -- Social conditions , Africa, Sub-Saharan -- Economic conditions , Africa, Sub-Saharan -- Economic policy
- Language: English
- Type: Thesis , Masters , MEcon
- Identifier: vital:1098 , http://hdl.handle.net/10962/d1013137
- Description: The purpose of the study has been to assess the question of sustainability of economic growth and human development, particularly using sub-Saharan Africa in context. Sub-Saharan Africa is an interesting case study because, on the one hand, it has been mired in poverty and remains the least developed region in the world, and on the other, it has experienced a revival in economic growth since the mid-1990s. Economists tend to use the term economic development and economic growth interchangeably. However, questions have been raised about whether Africa’s latest growth episode is indeed ‘development’. Although there are many issues at stake, the key question, and the focus of this thesis, is whether sub-Saharan Africa’s revival is sustainable. The paper sets out the debate between the ‘World Bank view’ and the ‘alternative view’. The main debate lies around how genuine development should be achieved. Firstly, the ‘World Bank view’ claims that economic growth is necessary and sufficient condition to achieve development. Economic growth will be generated by ‘orthodox’ policies and this growth will automatically trickle-down and stimulate development. Secondly, the ‘alternative view’ argues that economic growth is necessary but it is not sufficient to stimulate sustainable development. Economic growth without ‘qualitative’ change is not ‘sustainable’. Indeed, human development shortfalls (as well as other, social, political and structural problems), if not addressed through appropriate policy interventions, can undermine economic growth. The ‘alternative view’ appears to be strongly supported by evidence from other developing regions such as Latin America and East Asia. The empirical study conducted in this thesis reinforces doubts about ‘sustainability’. Even though there are signs of convergence in some indicators; this is not the case for all indicators. More importantly the gap between sub-Saharan Africa and other developing regions remains very wide. Sub-Saharan Africa’s development path remains uncertain. The intention in this study is not to be conclusive that sub-Saharan Africa cannot achieve sustainable development. Rather the study attempts to identify potential hindrances to sub-Saharan Africa’s development and to provide a solid foundation for further research in the same direction.
- Full Text:
- Authors: Hadisi Basingene, Serge
- Date: 2014
- Subjects: Sustainable development -- Africa, Sub-Saharan , Economic development -- Africa, Sub-Saharan , Poverty -- Africa, Sub-Saharan , Africa, Sub-Saharan -- Social conditions , Africa, Sub-Saharan -- Economic conditions , Africa, Sub-Saharan -- Economic policy
- Language: English
- Type: Thesis , Masters , MEcon
- Identifier: vital:1098 , http://hdl.handle.net/10962/d1013137
- Description: The purpose of the study has been to assess the question of sustainability of economic growth and human development, particularly using sub-Saharan Africa in context. Sub-Saharan Africa is an interesting case study because, on the one hand, it has been mired in poverty and remains the least developed region in the world, and on the other, it has experienced a revival in economic growth since the mid-1990s. Economists tend to use the term economic development and economic growth interchangeably. However, questions have been raised about whether Africa’s latest growth episode is indeed ‘development’. Although there are many issues at stake, the key question, and the focus of this thesis, is whether sub-Saharan Africa’s revival is sustainable. The paper sets out the debate between the ‘World Bank view’ and the ‘alternative view’. The main debate lies around how genuine development should be achieved. Firstly, the ‘World Bank view’ claims that economic growth is necessary and sufficient condition to achieve development. Economic growth will be generated by ‘orthodox’ policies and this growth will automatically trickle-down and stimulate development. Secondly, the ‘alternative view’ argues that economic growth is necessary but it is not sufficient to stimulate sustainable development. Economic growth without ‘qualitative’ change is not ‘sustainable’. Indeed, human development shortfalls (as well as other, social, political and structural problems), if not addressed through appropriate policy interventions, can undermine economic growth. The ‘alternative view’ appears to be strongly supported by evidence from other developing regions such as Latin America and East Asia. The empirical study conducted in this thesis reinforces doubts about ‘sustainability’. Even though there are signs of convergence in some indicators; this is not the case for all indicators. More importantly the gap between sub-Saharan Africa and other developing regions remains very wide. Sub-Saharan Africa’s development path remains uncertain. The intention in this study is not to be conclusive that sub-Saharan Africa cannot achieve sustainable development. Rather the study attempts to identify potential hindrances to sub-Saharan Africa’s development and to provide a solid foundation for further research in the same direction.
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Isn’t it time to start thinking about ‘developing’ academic developers in a more systematic way?
- Quinn, Lynn, Vorster, Jo-Anne
- Authors: Quinn, Lynn , Vorster, Jo-Anne
- Date: 2014
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/66546 , vital:28961 , https://doi.org/10.1080/1360144X.2013.879719
- Description: publisher version , There is no defined route to becoming an academic developer. The research on pathways into the field (e.g. Kensington-Miller, Brailsford, and Gossman, 2012; McDonald, 2010; McDonald and Stockley, 2008) shows that in most cases ‘serendipity and chance played a role’ (McDonald, 2010, p. 40). Moreover, induction into academic development (AD) is often ad hoc, haphazard, and informal. Due to the changing higher education (HE) context, the field has grown exponentially and in many countries now plays a central role in institutions. This has generated increased demand for knowledgeable and competent developers that are able to contribute towards solving some vexing problems in contemporary HE. Current recruitment and induction processes of new developers do not necessarily meet this demand. In light of the above, we pose the question: given the changing context of HE and the field of AD, is it not time for us to induct newcomers into the field more systematically? As Kensington-Miller et al. (2012) suggest, we should not leave the induction of the next generation of developers to chance. We suggest that one way of ensuring appropriate induction is through a formal course for developers. Difficulties for newcomers to the field are illustrated by Kensington-Miller et al. (2012) when they report seeking ‘top tips’ at a HERDSA conference. We do not dismiss informal learning at conferences or the role of mentoring, coaching, apprenticeship, and so on, in inducting developers, nor do we minimise the benefits of relatively structured processes such as fellowship programmes, workshops, and postgraduate qualifications in related fields. However, these ways of induction may not offer novices the structured and systematic developmental opportunities needed to become developers able to fulfil varied, complex, and sometimes contradictory roles.
- Full Text: false
- Authors: Quinn, Lynn , Vorster, Jo-Anne
- Date: 2014
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/66546 , vital:28961 , https://doi.org/10.1080/1360144X.2013.879719
- Description: publisher version , There is no defined route to becoming an academic developer. The research on pathways into the field (e.g. Kensington-Miller, Brailsford, and Gossman, 2012; McDonald, 2010; McDonald and Stockley, 2008) shows that in most cases ‘serendipity and chance played a role’ (McDonald, 2010, p. 40). Moreover, induction into academic development (AD) is often ad hoc, haphazard, and informal. Due to the changing higher education (HE) context, the field has grown exponentially and in many countries now plays a central role in institutions. This has generated increased demand for knowledgeable and competent developers that are able to contribute towards solving some vexing problems in contemporary HE. Current recruitment and induction processes of new developers do not necessarily meet this demand. In light of the above, we pose the question: given the changing context of HE and the field of AD, is it not time for us to induct newcomers into the field more systematically? As Kensington-Miller et al. (2012) suggest, we should not leave the induction of the next generation of developers to chance. We suggest that one way of ensuring appropriate induction is through a formal course for developers. Difficulties for newcomers to the field are illustrated by Kensington-Miller et al. (2012) when they report seeking ‘top tips’ at a HERDSA conference. We do not dismiss informal learning at conferences or the role of mentoring, coaching, apprenticeship, and so on, in inducting developers, nor do we minimise the benefits of relatively structured processes such as fellowship programmes, workshops, and postgraduate qualifications in related fields. However, these ways of induction may not offer novices the structured and systematic developmental opportunities needed to become developers able to fulfil varied, complex, and sometimes contradictory roles.
- Full Text: false
ISSRs indicate that Chromolaena odorata invading southern Africa originates in Jamaica or Cuba
- Paterson, Iain D, Zachariades, Coastas
- Authors: Paterson, Iain D , Zachariades, Coastas
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/406105 , vital:70239 , xlink:href="https://doi.org/10.1016/j.biocontrol.2013.04.005"
- Description: Two biotypes of the invasive alien plant, Chromolaena odorata (L.) R.M. King and Rob. (Asteraceae: Eupatorieae), are recognized in the plant’s introduced distribution. The Asian/West African (A/WA) biotype is present in West and Central Africa, India, Southeast Asia and Oceania, while the southern African (SA) biotype is only present in southern Africa. Biological control using insect natural enemies has been significantly more successful against the A/WA biotype than the SA biotype, suggesting that host plant incompatibility may have resulted in reduced efficacy of biological control agents in southern Africa. Inter-Simple Sequence Repeats (ISSR) were used to identify the origin of the SA biotype as Jamaica or Cuba. The data also confirm that the SA biotype is genetically distinct from the A/WA biotype and that the SA biotype is the result of a separate introduction. Biological control agents for C. odorata in southern Africa should be sourced from Jamaica and Cuba in order to avoid host plant incompatibility problems.
- Full Text:
- Authors: Paterson, Iain D , Zachariades, Coastas
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/406105 , vital:70239 , xlink:href="https://doi.org/10.1016/j.biocontrol.2013.04.005"
- Description: Two biotypes of the invasive alien plant, Chromolaena odorata (L.) R.M. King and Rob. (Asteraceae: Eupatorieae), are recognized in the plant’s introduced distribution. The Asian/West African (A/WA) biotype is present in West and Central Africa, India, Southeast Asia and Oceania, while the southern African (SA) biotype is only present in southern Africa. Biological control using insect natural enemies has been significantly more successful against the A/WA biotype than the SA biotype, suggesting that host plant incompatibility may have resulted in reduced efficacy of biological control agents in southern Africa. Inter-Simple Sequence Repeats (ISSR) were used to identify the origin of the SA biotype as Jamaica or Cuba. The data also confirm that the SA biotype is genetically distinct from the A/WA biotype and that the SA biotype is the result of a separate introduction. Biological control agents for C. odorata in southern Africa should be sourced from Jamaica and Cuba in order to avoid host plant incompatibility problems.
- Full Text:
IziNambuzane: isiZulu names for insects
- Cockburn, Jessica J, Khumalo-Seegelken, B, Villet, Martin H
- Authors: Cockburn, Jessica J , Khumalo-Seegelken, B , Villet, Martin H
- Date: 2014
- Subjects: Insects -- South Africa -- KwaZulu-Natal -- Nomenclature , Zulu language -- Revival , Language policy -- South Africa -- KwaZulu-Natal , Native language and education -- Research -- South Africa -- KwaZulu-Natal , Ethnoentomology
- Language: English
- Type: Article
- Identifier: vital:6972 , http://hdl.handle.net/10962/d1014581
- Description: We provide a tool for communicating about insects in isiZulu to facilitate research and knowledge sharing in the fields of indigenous knowledge, cultural entomology, environmental education and community extensioninvolving isiZulu speakers. A total of 213 different names for 64 insect specimens were encountered among a sample of 67 respondents in 11 communities distributed across the province of KwaZulu-Natal, South Africa. This list includes 93 names that can be considered core isiZulu vocabulary and which are widely used to identify insects that are agriculturally, medically, domestically, culturally or ecologically common or significant. Substantial variation was found regarding the names for particular insects, especially between regions, suggesting dialectal differences between isiZulu speakers. Grammatical and social variation in names was also recorded. This study highlights interdisciplinary teamwork in the field of indigenous knowledge research and the influences affecting the standardisation of South African languages for technical and scientific work.
- Full Text:
- Authors: Cockburn, Jessica J , Khumalo-Seegelken, B , Villet, Martin H
- Date: 2014
- Subjects: Insects -- South Africa -- KwaZulu-Natal -- Nomenclature , Zulu language -- Revival , Language policy -- South Africa -- KwaZulu-Natal , Native language and education -- Research -- South Africa -- KwaZulu-Natal , Ethnoentomology
- Language: English
- Type: Article
- Identifier: vital:6972 , http://hdl.handle.net/10962/d1014581
- Description: We provide a tool for communicating about insects in isiZulu to facilitate research and knowledge sharing in the fields of indigenous knowledge, cultural entomology, environmental education and community extensioninvolving isiZulu speakers. A total of 213 different names for 64 insect specimens were encountered among a sample of 67 respondents in 11 communities distributed across the province of KwaZulu-Natal, South Africa. This list includes 93 names that can be considered core isiZulu vocabulary and which are widely used to identify insects that are agriculturally, medically, domestically, culturally or ecologically common or significant. Substantial variation was found regarding the names for particular insects, especially between regions, suggesting dialectal differences between isiZulu speakers. Grammatical and social variation in names was also recorded. This study highlights interdisciplinary teamwork in the field of indigenous knowledge research and the influences affecting the standardisation of South African languages for technical and scientific work.
- Full Text:
Journalism sourcing and credibility: a study of Raia Mwema’s use of anonymous sources
- Authors: Mkoko, Egbert
- Date: 2014
- Subjects: Raia Mwema , Newspapers -- Tanzania , Journalism -- Tanzania , Attribution of news -- Tanzania
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3529 , http://hdl.handle.net/10962/d1013219
- Description: This study analyses how readers impute credibility to the Tanzanian investigative newspaper Raia Mwema which, as a matter of routine journalistic practice, uses a high number of anonymous sources. Against the backdrop of a strong theoretical position, espoused by media studies theorists in both Western media contexts and in Africa, in which this practice is deemed to diminish the credibility of both journalists and their stories, the study’s main purpose is to examine how readers make sense of this very prevalent practice in a country that has recently opened up to media plurality. It also investigates where they locate the source of credibility for this high-selling newspaper, if not in the traditional way through its named sources of information. The study surveys the frequency of appearance of anonymous sources in this newspaper for the period of one year from January 2011 to December 2011. Then the study considered how this practice is viewed and understood by the wider journalistic community in Tanzania as well as looking into how the journalists and owners of Raia Mwema make choices about attributing their journalism. Lastly, the study engaged with particular readers to understand what sense they make of this practice in the wider landscape of Tanzanian media and the post-repressive political situation. The study makes use of theories of the sociology of news production so as to understand the context in which Raia Mwema has routinised the practice of anonymous attribution and whether the journalistic community and newspaper readers find the practice credible. The study also employs reception analysis in order to understand to what extent Raia Mwema readers negotiate and make sense of the mainly political, and often critical, media messages they get from newspaper. In this way, it introduces the importance of the reader in the production of meaning and of assessment of credibility of journalism. The interviews – ranging from journalists working at the paper, through the wider journalistic community and taking in the readership of the paper – show that theoretical considerations of journalistic credibility must take into account the political, social and media context in which journalism is produced. Pronouncements on the overuse of anonymous sources, without understanding the way readers and journalists negotiate the complexities of an actual situation, do not tell us much about credibility and how readers understand the messages they are given. From this study, it is clear that in African countries embarking on opening media systems, credibility involves more factors than have been discussed in the literature and that readers and journalists are sophisticated consumers and producers of media messages in countries that place a host of obstacles in the way of investigative journalism and open political communication.
- Full Text:
- Authors: Mkoko, Egbert
- Date: 2014
- Subjects: Raia Mwema , Newspapers -- Tanzania , Journalism -- Tanzania , Attribution of news -- Tanzania
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3529 , http://hdl.handle.net/10962/d1013219
- Description: This study analyses how readers impute credibility to the Tanzanian investigative newspaper Raia Mwema which, as a matter of routine journalistic practice, uses a high number of anonymous sources. Against the backdrop of a strong theoretical position, espoused by media studies theorists in both Western media contexts and in Africa, in which this practice is deemed to diminish the credibility of both journalists and their stories, the study’s main purpose is to examine how readers make sense of this very prevalent practice in a country that has recently opened up to media plurality. It also investigates where they locate the source of credibility for this high-selling newspaper, if not in the traditional way through its named sources of information. The study surveys the frequency of appearance of anonymous sources in this newspaper for the period of one year from January 2011 to December 2011. Then the study considered how this practice is viewed and understood by the wider journalistic community in Tanzania as well as looking into how the journalists and owners of Raia Mwema make choices about attributing their journalism. Lastly, the study engaged with particular readers to understand what sense they make of this practice in the wider landscape of Tanzanian media and the post-repressive political situation. The study makes use of theories of the sociology of news production so as to understand the context in which Raia Mwema has routinised the practice of anonymous attribution and whether the journalistic community and newspaper readers find the practice credible. The study also employs reception analysis in order to understand to what extent Raia Mwema readers negotiate and make sense of the mainly political, and often critical, media messages they get from newspaper. In this way, it introduces the importance of the reader in the production of meaning and of assessment of credibility of journalism. The interviews – ranging from journalists working at the paper, through the wider journalistic community and taking in the readership of the paper – show that theoretical considerations of journalistic credibility must take into account the political, social and media context in which journalism is produced. Pronouncements on the overuse of anonymous sources, without understanding the way readers and journalists negotiate the complexities of an actual situation, do not tell us much about credibility and how readers understand the messages they are given. From this study, it is clear that in African countries embarking on opening media systems, credibility involves more factors than have been discussed in the literature and that readers and journalists are sophisticated consumers and producers of media messages in countries that place a host of obstacles in the way of investigative journalism and open political communication.
- Full Text:
Kaffirmeid and other stories
- Authors: Madingwane, June
- Date: 2014
- Subjects: South African fiction (English) -- 21st century , Short stories, South African -- 21st century , Creative writing (Higher education) -- Research -- South Africa , Creative writing -- Fiction , South African fiction (English) -- Study and teaching (Higher)
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:5983 , http://hdl.handle.net/10962/d1015659
- Description: These stories are about people’s experiences in relationships and how they overcome and resolve problems with their partners. Some explore myths and unexplained occurrences that raise many questions.
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- Authors: Madingwane, June
- Date: 2014
- Subjects: South African fiction (English) -- 21st century , Short stories, South African -- 21st century , Creative writing (Higher education) -- Research -- South Africa , Creative writing -- Fiction , South African fiction (English) -- Study and teaching (Higher)
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:5983 , http://hdl.handle.net/10962/d1015659
- Description: These stories are about people’s experiences in relationships and how they overcome and resolve problems with their partners. Some explore myths and unexplained occurrences that raise many questions.
- Full Text:
Kedibone
- Authors: Mokae, Sabata Paul
- Date: 2014
- Subjects: Creative writing (Higher education) -- Research -- South Africa , Creative writing -- Fiction , South African fiction (English) -- Study and teaching (Higher) , South African fiction (English) -- 21st century
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:6000 , http://hdl.handle.net/10962/d1020883
- Description: A young woman from a rural village near Kimberley is killed by her husband in a fit of jealousy. Her illiterate mother is summoned to the hospital to authorize the removal of vital organs – eyes, liver, kidney and heart – for organ donation. But some members of the family feel that their child should not be buried with parts of her body missing. Thus begins a story that changes the lives of many people, both black and white, over the following twenty years.
- Full Text:
- Authors: Mokae, Sabata Paul
- Date: 2014
- Subjects: Creative writing (Higher education) -- Research -- South Africa , Creative writing -- Fiction , South African fiction (English) -- Study and teaching (Higher) , South African fiction (English) -- 21st century
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:6000 , http://hdl.handle.net/10962/d1020883
- Description: A young woman from a rural village near Kimberley is killed by her husband in a fit of jealousy. Her illiterate mother is summoned to the hospital to authorize the removal of vital organs – eyes, liver, kidney and heart – for organ donation. But some members of the family feel that their child should not be buried with parts of her body missing. Thus begins a story that changes the lives of many people, both black and white, over the following twenty years.
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