Drought responses of selected C₄ photosynthetic NADP-Me and NAD-Me Panicoideae and Aristidoideae grasses
- Authors: Venter, Nicolaas
- Date: 2015
- Subjects: Aristida , Panicum , Switchgrass , Grasses -- Effect of drought on , Grasses -- Phylogeny , Photosynthesis
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4272 , http://hdl.handle.net/10962/d1018549
- Description: Grass species within South Africa show a photosynthetic subtype and phylogenetic response to rainfall gradients, with Panicoideae species (NADP-Me and NAD-Me) inhabiting mesic environments, while Aristidoideae species (NADP-Me) inhabit more arid environments. It is predicted that climate change will alter rainfall patterns within southern Africa, which could have implications for grassland distributions and functional composition. Globally, and in South Africa, species distributions indicates that NAD-Me species have a preference for more arid environments, but this may be complicated by phylogeny as most NAD-Me species belong to the Chloridoideae subfamily. Additionally, differences in the metabolism and energetic requirements of different carboxylation types are expected to confer different ecological advantages, such as drought tolerance, but the role of these different pathways is not well understood. Based on natural distribution and photosynthetic subtype differences, it was hypothesised that Panicoideae NADP-Me species would be less drought tolerant than Panicoideae NAD-Me and Aristidoideae NADP-Me species and that subtypes and lineages would show different drought recovery rates. Furthermore, drought sensitivity would be of a metabolic and not a stomatal origin and plants that maintained favourable leaf water status would be more drought tolerant and recover faster. This was tested experimentally by comparing Panicoideae species (NADP-Me and NAD-Me) and NADP-Me species (Panicoideae and Aristidoideae). Plants were subjected to a progressive 58 day drought period and a recovery phase where gas exchange, chlorophyll fluorescence and leaf water relations were measured at select intervals. In conjunction with this, a rapid drought experiment was performed on Zea mays (NADP-Me: Panicoideae) plants where similar parameters were measured. Photosynthetic drought and recovery responses showed both a subtype and phylogenetic response. Panicoideae species were less drought tolerant than Aristidoideae species, although Panicoideae NAD-Me showed better recovery rates than Panicoideae NADP-Me species, while Aristidoideae species recovered the quickest. Panicoideae NAD-Me and Aristidoideae species maintained higher leaf water status during drought which contributed to the maintenance of PSII integrity and thus facilitated rapid photosynthetic recovery. During drought Panicoideae species showed greater metabolic limitations over Aristidoideae species and for the first time, lower metabolic limitations were associated with osmotic adjustment. This is a novel finding whereby osmotic adjustment and the subsequent maintenance of leaf water are key to preventing metabolic limitations of photosynthesis in C₄ grasses. Results from the Z. mays rapid drought study showed the limitations to photosynthesis were exclusively metabolic and unlikely to be a direct consequence of turgor loss. It was apparent that the response to drought was stronger amongst lineages, as NADP-Me species from different subfamilies showed a significant difference in drought tolerances. Aristidoideae species’ exceptional drought tolerance and predicted increased aridification could favour these species over Panicoideae species under future climates.
- Full Text:
- Authors: Venter, Nicolaas
- Date: 2015
- Subjects: Aristida , Panicum , Switchgrass , Grasses -- Effect of drought on , Grasses -- Phylogeny , Photosynthesis
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4272 , http://hdl.handle.net/10962/d1018549
- Description: Grass species within South Africa show a photosynthetic subtype and phylogenetic response to rainfall gradients, with Panicoideae species (NADP-Me and NAD-Me) inhabiting mesic environments, while Aristidoideae species (NADP-Me) inhabit more arid environments. It is predicted that climate change will alter rainfall patterns within southern Africa, which could have implications for grassland distributions and functional composition. Globally, and in South Africa, species distributions indicates that NAD-Me species have a preference for more arid environments, but this may be complicated by phylogeny as most NAD-Me species belong to the Chloridoideae subfamily. Additionally, differences in the metabolism and energetic requirements of different carboxylation types are expected to confer different ecological advantages, such as drought tolerance, but the role of these different pathways is not well understood. Based on natural distribution and photosynthetic subtype differences, it was hypothesised that Panicoideae NADP-Me species would be less drought tolerant than Panicoideae NAD-Me and Aristidoideae NADP-Me species and that subtypes and lineages would show different drought recovery rates. Furthermore, drought sensitivity would be of a metabolic and not a stomatal origin and plants that maintained favourable leaf water status would be more drought tolerant and recover faster. This was tested experimentally by comparing Panicoideae species (NADP-Me and NAD-Me) and NADP-Me species (Panicoideae and Aristidoideae). Plants were subjected to a progressive 58 day drought period and a recovery phase where gas exchange, chlorophyll fluorescence and leaf water relations were measured at select intervals. In conjunction with this, a rapid drought experiment was performed on Zea mays (NADP-Me: Panicoideae) plants where similar parameters were measured. Photosynthetic drought and recovery responses showed both a subtype and phylogenetic response. Panicoideae species were less drought tolerant than Aristidoideae species, although Panicoideae NAD-Me showed better recovery rates than Panicoideae NADP-Me species, while Aristidoideae species recovered the quickest. Panicoideae NAD-Me and Aristidoideae species maintained higher leaf water status during drought which contributed to the maintenance of PSII integrity and thus facilitated rapid photosynthetic recovery. During drought Panicoideae species showed greater metabolic limitations over Aristidoideae species and for the first time, lower metabolic limitations were associated with osmotic adjustment. This is a novel finding whereby osmotic adjustment and the subsequent maintenance of leaf water are key to preventing metabolic limitations of photosynthesis in C₄ grasses. Results from the Z. mays rapid drought study showed the limitations to photosynthesis were exclusively metabolic and unlikely to be a direct consequence of turgor loss. It was apparent that the response to drought was stronger amongst lineages, as NADP-Me species from different subfamilies showed a significant difference in drought tolerances. Aristidoideae species’ exceptional drought tolerance and predicted increased aridification could favour these species over Panicoideae species under future climates.
- Full Text:
Dynamic mitochondrial localisation of STAT3 in the cellular adipogenesis model 3T3-L1:
- Kramer, Adam H, Edkins, Adrienne L, Hoppe, Heinrich C, Prinsloo, Earl
- Authors: Kramer, Adam H , Edkins, Adrienne L , Hoppe, Heinrich C , Prinsloo, Earl
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/164885 , vital:41181 , DOI: 10.1002/jcb.25076
- Description: A mechanistic relationship exists between protein localisation, activity and cellular differentiation. Understanding the contribution of these molecular mechanisms is required for elucidation of conditions that drive development. Literature suggests non‐canonical translocation of the Signal Transducer and Activator of Transcription 3 (STAT3) to the mitochondria contributes to the regulation of the electron transport chain, cellular respiration and reactive oxygen species production. Based on this we investigated the role of mitochondrial STAT3, specifically the serine 727 phosphorylated form, in cellular differentiation using the well‐defined mouse adipogenic model 3T3-L1.
- Full Text:
- Authors: Kramer, Adam H , Edkins, Adrienne L , Hoppe, Heinrich C , Prinsloo, Earl
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/164885 , vital:41181 , DOI: 10.1002/jcb.25076
- Description: A mechanistic relationship exists between protein localisation, activity and cellular differentiation. Understanding the contribution of these molecular mechanisms is required for elucidation of conditions that drive development. Literature suggests non‐canonical translocation of the Signal Transducer and Activator of Transcription 3 (STAT3) to the mitochondria contributes to the regulation of the electron transport chain, cellular respiration and reactive oxygen species production. Based on this we investigated the role of mitochondrial STAT3, specifically the serine 727 phosphorylated form, in cellular differentiation using the well‐defined mouse adipogenic model 3T3-L1.
- Full Text:
E-commerce: the challenge of virtual permanent establishments
- Adlkofer, Michelle Leigh, Venter, Michelle
- Authors: Adlkofer, Michelle Leigh , Venter, Michelle
- Date: 2015
- Subjects: Organisation for Economic Co-operation and Development , Electronic commerce , Electronic commerce -- Taxation , Double taxation -- Treaties , Globalization
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:921 , http://hdl.handle.net/10962/d1020057
- Description: The continued growth of world commerce has led to the advance of the permanent establishment principles. These principles are, however, constantly challenged by the developments of e-commerce. This thesis considers the taxing of a permanent establishment and the influence of e-commerce on the concept of a permanent establishment. In 2000, the Organisation for Economic Co-operation and Development (“OECD”) developed and introduced guidelines on how to deal with e-commerce in the context of a permanent establishment. Since the OECD guidelines on e-commerce were issued, the permanent establishment principles have come under further scrutiny. The latest development came about in 2013 with the release of the Base Erosion and Profit Shifting (“BEPS”) Action Plan. This Action Plan addresses the intention of the OECD to deal with the taxing of the digital economy. With the development of e-commerce and the result of e-commerce creating intangible boundaries between countries, the concept of a virtual permanent establishment has emerged. This has resulted in the need to tax a presence of an enterprise in a jurisdiction where no actual physical connection can be established. Various authors have made suggestions on how to ensure that an economy in which business is being carried on is correctly compensated for in the form of taxes. The source of income is the driving force for the imposition of taxation today. The main goal of this thesis was to explore the alignment of the concepts of a permanent establishment and e-commerce in the digital economy. This study therefore examined the concepts of both permanent establishments and e-commerce, and explored authors’ views and suggestions on how to deal with the inter-related effects of these two concepts. The relevant Action Points in the OECD Action Plan were also considered. , Maiden name: Venter, Michelle
- Full Text:
- Authors: Adlkofer, Michelle Leigh , Venter, Michelle
- Date: 2015
- Subjects: Organisation for Economic Co-operation and Development , Electronic commerce , Electronic commerce -- Taxation , Double taxation -- Treaties , Globalization
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:921 , http://hdl.handle.net/10962/d1020057
- Description: The continued growth of world commerce has led to the advance of the permanent establishment principles. These principles are, however, constantly challenged by the developments of e-commerce. This thesis considers the taxing of a permanent establishment and the influence of e-commerce on the concept of a permanent establishment. In 2000, the Organisation for Economic Co-operation and Development (“OECD”) developed and introduced guidelines on how to deal with e-commerce in the context of a permanent establishment. Since the OECD guidelines on e-commerce were issued, the permanent establishment principles have come under further scrutiny. The latest development came about in 2013 with the release of the Base Erosion and Profit Shifting (“BEPS”) Action Plan. This Action Plan addresses the intention of the OECD to deal with the taxing of the digital economy. With the development of e-commerce and the result of e-commerce creating intangible boundaries between countries, the concept of a virtual permanent establishment has emerged. This has resulted in the need to tax a presence of an enterprise in a jurisdiction where no actual physical connection can be established. Various authors have made suggestions on how to ensure that an economy in which business is being carried on is correctly compensated for in the form of taxes. The source of income is the driving force for the imposition of taxation today. The main goal of this thesis was to explore the alignment of the concepts of a permanent establishment and e-commerce in the digital economy. This study therefore examined the concepts of both permanent establishments and e-commerce, and explored authors’ views and suggestions on how to deal with the inter-related effects of these two concepts. The relevant Action Points in the OECD Action Plan were also considered. , Maiden name: Venter, Michelle
- Full Text:
Earnings quality and equity returns : evidence of the accrual anomaly from the South African equity market
- Authors: Lutchmun, Thashveen
- Date: 2015
- Subjects: Earnings management -- South Africa , Accounting -- Standards
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:915 , http://hdl.handle.net/10962/d1017537
- Description: A key incentive for accounting research is to provide evidence on the usefulness of earnings in making economic decisions. Of particular interest over the last two decades is the issue of the quality of financial reporting, specifically the quality of earnings, given the number of global financial scandals reported during that period. The quality of earnings is driven by the choices, estimates and judgments that the accounting standards make available to managers in order to portray the firm’s economic position and performance in a timely and credible manner. However, this leeway in financial reporting also creates opportunities for earnings management. The objective of this thesis is firstly to establish whether earnings manipulation has had the ability to predict cross-sectional returns in South Africa during the 2007-2014 period. In other words, the purpose of this thesis is to find evidence whether the market reacts to earnings management practices, as measured by accruals, and rewards high earnings quality companies with higher equity returns (a process known as the accrual anomaly). The timeframe selected for the research encompasses the global financial crisis, a period in which accounting manipulation incentives are likely to be strong. Secondly, this study attempts to establish the presence of the accrual anomaly amongst growth and value firms. The motivations for earnings management of the former are expected to be strong. Securities are allocated to portfolios according to accruals and the subsequent equity returns are analysed cross-sectionally to establish the existence of the accrual anomaly and hence assessing the usefulness of earnings manipulation in predicting equity returns. To provide evidence for the presence of the accrual anomaly amongst growth and value shares, securities are independently allocated to portfolios according to their book-to-market ratio and accruals and a cross-sectional analysis is performed on their subsequent equity returns. In order to increase the robustness of the tests, two measures of accruals are used: a balance sheet approach and a cash flow measure. Evidence is provided for the presence of the accrual anomaly among South African listed companies for the balance sheet measure of accruals but not the cash flow approach. Whilst the accrual anomaly is significantly present in a growth-neutral-value construct, statistical significance is not established when growth and value shares are considered individually.
- Full Text:
- Authors: Lutchmun, Thashveen
- Date: 2015
- Subjects: Earnings management -- South Africa , Accounting -- Standards
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:915 , http://hdl.handle.net/10962/d1017537
- Description: A key incentive for accounting research is to provide evidence on the usefulness of earnings in making economic decisions. Of particular interest over the last two decades is the issue of the quality of financial reporting, specifically the quality of earnings, given the number of global financial scandals reported during that period. The quality of earnings is driven by the choices, estimates and judgments that the accounting standards make available to managers in order to portray the firm’s economic position and performance in a timely and credible manner. However, this leeway in financial reporting also creates opportunities for earnings management. The objective of this thesis is firstly to establish whether earnings manipulation has had the ability to predict cross-sectional returns in South Africa during the 2007-2014 period. In other words, the purpose of this thesis is to find evidence whether the market reacts to earnings management practices, as measured by accruals, and rewards high earnings quality companies with higher equity returns (a process known as the accrual anomaly). The timeframe selected for the research encompasses the global financial crisis, a period in which accounting manipulation incentives are likely to be strong. Secondly, this study attempts to establish the presence of the accrual anomaly amongst growth and value firms. The motivations for earnings management of the former are expected to be strong. Securities are allocated to portfolios according to accruals and the subsequent equity returns are analysed cross-sectionally to establish the existence of the accrual anomaly and hence assessing the usefulness of earnings manipulation in predicting equity returns. To provide evidence for the presence of the accrual anomaly amongst growth and value shares, securities are independently allocated to portfolios according to their book-to-market ratio and accruals and a cross-sectional analysis is performed on their subsequent equity returns. In order to increase the robustness of the tests, two measures of accruals are used: a balance sheet approach and a cash flow measure. Evidence is provided for the presence of the accrual anomaly among South African listed companies for the balance sheet measure of accruals but not the cash flow approach. Whilst the accrual anomaly is significantly present in a growth-neutral-value construct, statistical significance is not established when growth and value shares are considered individually.
- Full Text:
Ecological sustainability for non-timber forest products: dynamics and case studies of harvesting
- Shackleton, Charlie M, Pandey, Ashok K, Ticktin, Tamara
- Authors: Shackleton, Charlie M , Pandey, Ashok K , Ticktin, Tamara
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10962/433656 , vital:72992 , ISBN 9781317916130 , https://www.routledge.com/Ecological-Sustainability-for-Non-timber-Forest-Products-Dynamics-and-Case/Shackleton-Pandey-Ticktin/p/book/9781138618251
- Description: There is growing knowledge about and appreciation of the im-portance of Non-timber Forest Products (NTFPs) to rural liveli-hoods in developing countries, and to a lesser extent, devel-oped countries. However, there is also an assumption on the part of policy-makers that any harvesting of wild animal or plant products from the forests and other natural and modi-fied ecosystems must be detrimental to the long-term viability of target populations and species. This book challenges this idea and shows that while examples of such negative impacts certainly exist, there are also many examples of sustainable harvesting systems for NTFPs. The chapters review and pre-sent coherent and scientifically sound information and case studies on the ecologically sustainable use of NTFPs. They also outline a general interdisciplinary approach for assessing the sustainability of NTFP harvesting systems at different scales. A wide range of case studies is included from Africa, Asia and South America, using plant and animal products for food, crafts, textiles, medicines and cosmetics.
- Full Text:
- Authors: Shackleton, Charlie M , Pandey, Ashok K , Ticktin, Tamara
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10962/433656 , vital:72992 , ISBN 9781317916130 , https://www.routledge.com/Ecological-Sustainability-for-Non-timber-Forest-Products-Dynamics-and-Case/Shackleton-Pandey-Ticktin/p/book/9781138618251
- Description: There is growing knowledge about and appreciation of the im-portance of Non-timber Forest Products (NTFPs) to rural liveli-hoods in developing countries, and to a lesser extent, devel-oped countries. However, there is also an assumption on the part of policy-makers that any harvesting of wild animal or plant products from the forests and other natural and modi-fied ecosystems must be detrimental to the long-term viability of target populations and species. This book challenges this idea and shows that while examples of such negative impacts certainly exist, there are also many examples of sustainable harvesting systems for NTFPs. The chapters review and pre-sent coherent and scientifically sound information and case studies on the ecologically sustainable use of NTFPs. They also outline a general interdisciplinary approach for assessing the sustainability of NTFP harvesting systems at different scales. A wide range of case studies is included from Africa, Asia and South America, using plant and animal products for food, crafts, textiles, medicines and cosmetics.
- Full Text:
Ecologically sustainable harvesting of non-timber forest products: Disarming the narrative and the complexity
- Shackleton, Charlie M, Pandey, Ashok K, Ticktin, Tamara
- Authors: Shackleton, Charlie M , Pandey, Ashok K , Ticktin, Tamara
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/433670 , vital:72993 , ISBN 9781317916130 , https://www.routledge.com/Ecological-Sustainability-for-Non-timber-Forest-Products-Dynamics-and-Case/Shackleton-Pandey-Ticktin/p/book/9781138618251
- Description: As introduced at the outset of this book, the need for ecologically sustainable harvesting systems for tens of thousands of non-timber forest products (NTFPs) around the world is a requirement for the conservation of the species concerned, and the lives, livelihoods and economies that depend on those species. Ecological sustainability is not simply a ‘nice to have’, a marketing ploy or a conservation fad. Unsustainable harvesting leads to the decline, sooner or later, of NTFP gene pools, populations and species and hence the livelihoods, and species and ecosystem services dependent upon them. Often the negative impacts on peoples’ lives and incomes are not immediately apparent because they may substitute the diminishing returns from one species by harvesting another species, such as favoured firewood species for less preferred species (Madubansi and Shackleton 2007). However, the second, third or more substitute yields lower returns in quality or quantity (or both) than the most preferred species and so a trajectory of dwindling returns looms, either of the benefits obtained, or increased costs to access the benefits. On the other hand, the concept of an ecologically sustainable yield is relatively easy to grasp (Ticktin Chapter 3). All biological resources are renewable. If the rate of harvest is less than the rate of renewal, then the NTFP species or population should persist in the long term. This simplistic picture needs to be fine-tuned to ensure that there are no exacerbatory or synergistic impacts associated with the direct effects of harvesting (such as changes in browsing patterns or fire behaviour)(Ticktin and Shackleton 2011, Ticktin Chapter 3). Additionally, the effects at broader scales, ie beyond just the target species, need to be also taken into account, such as on pollinators, decomposers, nutrient cycles and the like (Ticktin 2004). But in principle, the definition and measurement of an ecologically sustainable yield is well within the means of modern science for the majority of plant and animal NTFP species.
- Full Text:
- Authors: Shackleton, Charlie M , Pandey, Ashok K , Ticktin, Tamara
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/433670 , vital:72993 , ISBN 9781317916130 , https://www.routledge.com/Ecological-Sustainability-for-Non-timber-Forest-Products-Dynamics-and-Case/Shackleton-Pandey-Ticktin/p/book/9781138618251
- Description: As introduced at the outset of this book, the need for ecologically sustainable harvesting systems for tens of thousands of non-timber forest products (NTFPs) around the world is a requirement for the conservation of the species concerned, and the lives, livelihoods and economies that depend on those species. Ecological sustainability is not simply a ‘nice to have’, a marketing ploy or a conservation fad. Unsustainable harvesting leads to the decline, sooner or later, of NTFP gene pools, populations and species and hence the livelihoods, and species and ecosystem services dependent upon them. Often the negative impacts on peoples’ lives and incomes are not immediately apparent because they may substitute the diminishing returns from one species by harvesting another species, such as favoured firewood species for less preferred species (Madubansi and Shackleton 2007). However, the second, third or more substitute yields lower returns in quality or quantity (or both) than the most preferred species and so a trajectory of dwindling returns looms, either of the benefits obtained, or increased costs to access the benefits. On the other hand, the concept of an ecologically sustainable yield is relatively easy to grasp (Ticktin Chapter 3). All biological resources are renewable. If the rate of harvest is less than the rate of renewal, then the NTFP species or population should persist in the long term. This simplistic picture needs to be fine-tuned to ensure that there are no exacerbatory or synergistic impacts associated with the direct effects of harvesting (such as changes in browsing patterns or fire behaviour)(Ticktin and Shackleton 2011, Ticktin Chapter 3). Additionally, the effects at broader scales, ie beyond just the target species, need to be also taken into account, such as on pollinators, decomposers, nutrient cycles and the like (Ticktin 2004). But in principle, the definition and measurement of an ecologically sustainable yield is well within the means of modern science for the majority of plant and animal NTFP species.
- Full Text:
Editorial. Perspectives on transformations in learning and education
- Authors: Lotz-Sisitka, Heila
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/387277 , vital:68221 , xlink:href="https://www.ajol.info/index.php/sajee/article/view/137656"
- Description: Perspectives on transformations in learning and education
- Full Text:
- Authors: Lotz-Sisitka, Heila
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/387277 , vital:68221 , xlink:href="https://www.ajol.info/index.php/sajee/article/view/137656"
- Description: Perspectives on transformations in learning and education
- Full Text:
Effect of conventional and organic orchard floor management practices on arbuscular mycorrhizal fungi in a ‘Cripp’s Pink’/M7 apple orchard soil
- Meyer, André H, Wooldridge, John, Dames, Joanna F
- Authors: Meyer, André H , Wooldridge, John , Dames, Joanna F
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/444012 , vital:74178 , https://doi.org/10.1016/j.agee.2015.07.026
- Description: Arbuscular mycorrhizal (AM) fungi are key components of agricultural soil–plant systems, which may be affected by agricultural practices. In organically managed (ORG) orchards, nutrients are supplied in the form of compost, and weeds are suppressed with mulches, whereas synthetic fertilizers and herbicides are used for these respective purposes in conventional (CON) orchards. The effects of ORG and CON orchard floor management practices on native AM fungi in apple orchards were investigated in a randomized field trial. AM root colonization, spore abundance, infectivity potentials and soil glomalin contents were determined in the 0–30 cm soil depth interval, in tree rows, over consecutive seasons. Root colonization was higher in the ORG than the CON treatments, but intermediate where straw mulch was substituted for green work-row covers. Glomalin levels were not affected by the treatments. Root colonization by AM fungi increased with increasing soil pH, P, C, K, Zn, and Mn concentrations, but were suppressed by Cu. Colonization correlated positively with leaf P, Ca and Mg, and with stem circumference, but negatively with leaf N and yield. ORG orchard floor management practices therefore, promoted functional AM associations more effectively than CON practices.
- Full Text:
- Authors: Meyer, André H , Wooldridge, John , Dames, Joanna F
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/444012 , vital:74178 , https://doi.org/10.1016/j.agee.2015.07.026
- Description: Arbuscular mycorrhizal (AM) fungi are key components of agricultural soil–plant systems, which may be affected by agricultural practices. In organically managed (ORG) orchards, nutrients are supplied in the form of compost, and weeds are suppressed with mulches, whereas synthetic fertilizers and herbicides are used for these respective purposes in conventional (CON) orchards. The effects of ORG and CON orchard floor management practices on native AM fungi in apple orchards were investigated in a randomized field trial. AM root colonization, spore abundance, infectivity potentials and soil glomalin contents were determined in the 0–30 cm soil depth interval, in tree rows, over consecutive seasons. Root colonization was higher in the ORG than the CON treatments, but intermediate where straw mulch was substituted for green work-row covers. Glomalin levels were not affected by the treatments. Root colonization by AM fungi increased with increasing soil pH, P, C, K, Zn, and Mn concentrations, but were suppressed by Cu. Colonization correlated positively with leaf P, Ca and Mg, and with stem circumference, but negatively with leaf N and yield. ORG orchard floor management practices therefore, promoted functional AM associations more effectively than CON practices.
- Full Text:
Effect of temperature on development of the blowfly, Lucilia cuprina (Wiedemann)(Diptera: Calliphoridae)
- Kotzé, Zanthé, Villet, Martin H, Weldon, Christopher W
- Authors: Kotzé, Zanthé , Villet, Martin H , Weldon, Christopher W
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/442116 , vital:73960 , https://doi.org/10.1007/s00414-015-1153-y
- Description: The blowfly Lucilia cuprina is a primary colonizer of decaying vertebrate carrion, and its development provides a temperature-dependent clock that may be used to estimate the post-mortem interval of corpses and carcasses in medicolegal forensic investigations. This study uses the development of L. cuprina raised on a substrate of chicken liver at six constant temperatures from 18 to 33 °C to calibrate a thermal accumulation model of development for forensic applications. Development was optimal near 24 °C; above this temperature, survival of post-feeding life stages was increasingly compromised, while below it, development was increasingly retarded. The lower developmental threshold (~12 °C) and thermal summation constants of L. cuprina are distinct from those reported for Lucilia sericata, verifying that it is essential to identify African Lucilia specimens accurately when using them to estimate post-mortem intervals.
- Full Text:
- Authors: Kotzé, Zanthé , Villet, Martin H , Weldon, Christopher W
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/442116 , vital:73960 , https://doi.org/10.1007/s00414-015-1153-y
- Description: The blowfly Lucilia cuprina is a primary colonizer of decaying vertebrate carrion, and its development provides a temperature-dependent clock that may be used to estimate the post-mortem interval of corpses and carcasses in medicolegal forensic investigations. This study uses the development of L. cuprina raised on a substrate of chicken liver at six constant temperatures from 18 to 33 °C to calibrate a thermal accumulation model of development for forensic applications. Development was optimal near 24 °C; above this temperature, survival of post-feeding life stages was increasingly compromised, while below it, development was increasingly retarded. The lower developmental threshold (~12 °C) and thermal summation constants of L. cuprina are distinct from those reported for Lucilia sericata, verifying that it is essential to identify African Lucilia specimens accurately when using them to estimate post-mortem intervals.
- Full Text:
Effects of differently shaped silver nanoparticles on the photophysics of pyridylsulfanyl-substituted phthalocyanines
- D'Souza, Sarah, Mashazi, Philani N, Britton, Jonathan, Nyokong, Tebello
- Authors: D'Souza, Sarah , Mashazi, Philani N , Britton, Jonathan , Nyokong, Tebello
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/193564 , vital:45348 , xlink:href="https://doi.org/10.1016/j.poly.2015.06.038"
- Description: This paper reports on the photophysical behavior of (2-pyridylsulfanyl)phthalocyaninato zinc(II) and 2,9(10),16(17),23(24)-tetra-(2-pyridylsulfanyl)phthalocyaninato zinc(II) in the presence of differently shaped silver nanoparticles (nanospheres, nanotriangles and nanoflowers). The presence of shaped nanoparticles increased both triplet quantum yields and lifetimes of the tetra-substituted mercaptopyridine zinc phthalocyanine in DMSO. It is apparent from this work that the shape of the silver nanoparticle used is of little consequence in influencing photophysical behavior of the phthalocyanines.
- Full Text:
- Authors: D'Souza, Sarah , Mashazi, Philani N , Britton, Jonathan , Nyokong, Tebello
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/193564 , vital:45348 , xlink:href="https://doi.org/10.1016/j.poly.2015.06.038"
- Description: This paper reports on the photophysical behavior of (2-pyridylsulfanyl)phthalocyaninato zinc(II) and 2,9(10),16(17),23(24)-tetra-(2-pyridylsulfanyl)phthalocyaninato zinc(II) in the presence of differently shaped silver nanoparticles (nanospheres, nanotriangles and nanoflowers). The presence of shaped nanoparticles increased both triplet quantum yields and lifetimes of the tetra-substituted mercaptopyridine zinc phthalocyanine in DMSO. It is apparent from this work that the shape of the silver nanoparticle used is of little consequence in influencing photophysical behavior of the phthalocyanines.
- Full Text:
Effects of inoculating Lachnum and Cadophora isolates on the growth of Vaccinium corymbosum
- Mbizabani, Christine, Dames, Joanna F
- Authors: Mbizabani, Christine , Dames, Joanna F
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/444024 , vital:74179 , https://doi.org/10.1016/j.micres.2015.08.005
- Description: The roots of ericaceous plants harbour a diversity of fungal taxa, which confer eco-physiological benefits to the host. Some of the fungi have been established to form ericoid mycorrhizal (ERM) associations and enhance plant growth in certain ericaceous genera. Although, Lachnum and Cadophora isolates have frequently been identified from the roots of this family, the status of their association and functional roles is still vague. The aims of this study were to identify Lachnum and Cadophora isolates; determine the root-fungal interactive structures formed in associations with Vaccinium corymbosum L. (blueberry) hosts and to examine inoculation effects of the fungal associates using several varieties of the blueberry. Lachnum and Cadophora were isolated and identified from Erica cerinthoides L. and Erica demmissa Klotzsch ex Benth using morphological and molecular techniques. Micropropagated blueberry varieties (Bluecrop, Elliott, Spartan, Chandler and Brightwell) were inoculated with respective fungi and plant growth evaluated. Both fungi colonised the roots and did not have any pathogenic effect.
- Full Text:
- Authors: Mbizabani, Christine , Dames, Joanna F
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/444024 , vital:74179 , https://doi.org/10.1016/j.micres.2015.08.005
- Description: The roots of ericaceous plants harbour a diversity of fungal taxa, which confer eco-physiological benefits to the host. Some of the fungi have been established to form ericoid mycorrhizal (ERM) associations and enhance plant growth in certain ericaceous genera. Although, Lachnum and Cadophora isolates have frequently been identified from the roots of this family, the status of their association and functional roles is still vague. The aims of this study were to identify Lachnum and Cadophora isolates; determine the root-fungal interactive structures formed in associations with Vaccinium corymbosum L. (blueberry) hosts and to examine inoculation effects of the fungal associates using several varieties of the blueberry. Lachnum and Cadophora were isolated and identified from Erica cerinthoides L. and Erica demmissa Klotzsch ex Benth using morphological and molecular techniques. Micropropagated blueberry varieties (Bluecrop, Elliott, Spartan, Chandler and Brightwell) were inoculated with respective fungi and plant growth evaluated. Both fungi colonised the roots and did not have any pathogenic effect.
- Full Text:
Effects of ZnO nanohexagons and nanorods on the fluorescence behavior of metallophthalocyanines
- D'Souza, Sarah, Moeno, Sharon, Nyokong, Tebello
- Authors: D'Souza, Sarah , Moeno, Sharon , Nyokong, Tebello
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/189741 , vital:44927 , xlink:href="https://doi.org/10.1016/j.poly.2014.09.012"
- Description: This paper looks at the fluorescence behavior of zinc phthalocyanines: 2,(3),9(10),16(17),23(24)-tetrakis- (mercaptoacetic acid phthalocyaninato) zinc(II) (ZnTMAAPc), 2,(3),9(10),16(17),23(24)-tetrakis-(mercaptopropanoic acid phthalocyaninato) zinc(II) (ZnTMPAPc) and (OH)AlPcSmix (the latter contains a mixture of the di-, tri- and tetra-sulfonated derivatives with an average of three sulfonated groups per molecule) in the presence of ZnO nanoparticles. Fluorescence lifetimes of Pc complexes generally decreased in the presence of ZnO nanoparticles, with generally longer lifetimes for ZnO nanohexagons compared to ZnO nanorods.
- Full Text:
- Authors: D'Souza, Sarah , Moeno, Sharon , Nyokong, Tebello
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/189741 , vital:44927 , xlink:href="https://doi.org/10.1016/j.poly.2014.09.012"
- Description: This paper looks at the fluorescence behavior of zinc phthalocyanines: 2,(3),9(10),16(17),23(24)-tetrakis- (mercaptoacetic acid phthalocyaninato) zinc(II) (ZnTMAAPc), 2,(3),9(10),16(17),23(24)-tetrakis-(mercaptopropanoic acid phthalocyaninato) zinc(II) (ZnTMPAPc) and (OH)AlPcSmix (the latter contains a mixture of the di-, tri- and tetra-sulfonated derivatives with an average of three sulfonated groups per molecule) in the presence of ZnO nanoparticles. Fluorescence lifetimes of Pc complexes generally decreased in the presence of ZnO nanoparticles, with generally longer lifetimes for ZnO nanohexagons compared to ZnO nanorods.
- Full Text:
Electrocatalytic activity of bimetallic Au–Pd nanoparticles in the presence of cobalt tetraaminophthalocyanine
- Maringa, Audacity, Mashazi, Philani N, Nyokong, Tebello
- Authors: Maringa, Audacity , Mashazi, Philani N , Nyokong, Tebello
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/189719 , vital:44925 , xlink:href="https://doi.org/10.1016/j.jcis.2014.10.056"
- Description: Au and Pd nanoparticles were individually or together electrodeposited on top of polymerized cobalt tetraaminophthalocyanine (poly-CoTAPc). When Pd and Au nanoparticles are co-deposited together, the electrode is denoted as Au–Pd (co-deposited)/poly-CoTAPc-GCE. X-ray photoelectron spectroscopy (XPS) was used to show the successful deposition of AuNPs, PdNPs and Au–Pd (co-deposited). The scanning electrochemical microscopy showed that Au–Pd (co-deposited)/poly-CoTAPc-GCE (with current range of 9.5–13.5 lA) was more conducting than Au–Pd (co-deposited)-GCE (with current range of 8–12 lA). Electrochemical impedance spectroscopy (EIS) showed that there was less resistance to charge transfer for Au–Pd (co-deposited)/poly-CoTAPc-GCE compared to the rest of the electrodes. Au–Pd (co-deposited)/poly-CoTAPc-GCE showed the best activity for the electrooxidation of hydrazine in terms of limit of detection (0.5 lM), hence shows promise as an electrocatalyst for electrooxidation of hydrazine.
- Full Text:
- Authors: Maringa, Audacity , Mashazi, Philani N , Nyokong, Tebello
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/189719 , vital:44925 , xlink:href="https://doi.org/10.1016/j.jcis.2014.10.056"
- Description: Au and Pd nanoparticles were individually or together electrodeposited on top of polymerized cobalt tetraaminophthalocyanine (poly-CoTAPc). When Pd and Au nanoparticles are co-deposited together, the electrode is denoted as Au–Pd (co-deposited)/poly-CoTAPc-GCE. X-ray photoelectron spectroscopy (XPS) was used to show the successful deposition of AuNPs, PdNPs and Au–Pd (co-deposited). The scanning electrochemical microscopy showed that Au–Pd (co-deposited)/poly-CoTAPc-GCE (with current range of 9.5–13.5 lA) was more conducting than Au–Pd (co-deposited)-GCE (with current range of 8–12 lA). Electrochemical impedance spectroscopy (EIS) showed that there was less resistance to charge transfer for Au–Pd (co-deposited)/poly-CoTAPc-GCE compared to the rest of the electrodes. Au–Pd (co-deposited)/poly-CoTAPc-GCE showed the best activity for the electrooxidation of hydrazine in terms of limit of detection (0.5 lM), hence shows promise as an electrocatalyst for electrooxidation of hydrazine.
- Full Text:
Electrocatalytic studies of covalently immobilized metal tetra-amino phthalocyanines onto derivatized screen-printed gold electrodes
- Mashazi, Philani N, Nyokong, Tebello
- Authors: Mashazi, Philani N , Nyokong, Tebello
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/249059 , vital:51774 , xlink:href="https://doi.org/10.1007/s00604-010-0438-6"
- Description: Metal tetra-amino phthalocyanine complexes (MTAPc; where M is Co or Mn) were immobilized on screen-printed gold electrodes pre-modified with monolayers of benzylamino groups. The functionalized electrodes were then activated using benzene-1,4-dicarbaldehyde as a linker before MTAPc complexes were immobilized. The surface coverages for the modified electrodes confirmed the perpendicular orientation of the MTAPcs. The apparent electron transfer constant (kapp) for the electrodes is 2.2 × 10−5 cm.s−1 for both CoTAPc and MnTAPc modified electrodes as calculated with data from impedance measurements. The kapp values for the bare and benzylamino modified electrodes were found to be 1.2 × 10−4 cm.s−1 and 4.9 × 10−6 cm.s−1, respectively. The electrocatalysis of the modified electrodes towards detection of H2O2 gave significant peak current densities and electrocatalytic potentials at −0.28 V and −0.31 V for the MnTAPc and CoTAPc modified electrodes, respectively.
- Full Text:
- Authors: Mashazi, Philani N , Nyokong, Tebello
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/249059 , vital:51774 , xlink:href="https://doi.org/10.1007/s00604-010-0438-6"
- Description: Metal tetra-amino phthalocyanine complexes (MTAPc; where M is Co or Mn) were immobilized on screen-printed gold electrodes pre-modified with monolayers of benzylamino groups. The functionalized electrodes were then activated using benzene-1,4-dicarbaldehyde as a linker before MTAPc complexes were immobilized. The surface coverages for the modified electrodes confirmed the perpendicular orientation of the MTAPcs. The apparent electron transfer constant (kapp) for the electrodes is 2.2 × 10−5 cm.s−1 for both CoTAPc and MnTAPc modified electrodes as calculated with data from impedance measurements. The kapp values for the bare and benzylamino modified electrodes were found to be 1.2 × 10−4 cm.s−1 and 4.9 × 10−6 cm.s−1, respectively. The electrocatalysis of the modified electrodes towards detection of H2O2 gave significant peak current densities and electrocatalytic potentials at −0.28 V and −0.31 V for the MnTAPc and CoTAPc modified electrodes, respectively.
- Full Text:
Electrode modification using alkynyl substituted Fe (II) phthalocyanine via electrografting and click chemistry for electrocatalysis
- Nxele, Siphesihle R, Mashazi, Philani N, Nyokong, Tebello
- Authors: Nxele, Siphesihle R , Mashazi, Philani N , Nyokong, Tebello
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/189296 , vital:44835 , xlink:href="https://doi.org/10.1002/elan.201500212"
- Description: In this work, tetrakis(5-hexyn-oxy)Fe(II) phthalocyanine was synthesised in order to perform a click reaction between the terminal alkyne groups and an azide group on a glassy carbon electrode (GCE) surface. An azide group was formed on the electrode surface following electrografting using 4-azidobenzene diazonium tetrafluoroborate by electrochemical reduction. The Cu(I) catalyzed alkyne-azide Huisgen cycloaddition reaction was then employed in order to react the terminal alkyne groups on the phthalocyanine with the azide groups on the GCE surface. The modified electrode was employed to catalyse the oxidation of hydrazine. The electrode showed good electrocatalytic ability towards the detection of hydrazine with a sensitivity of 15.38 µA mM−1 and a limit of detection of 1.09 µM.
- Full Text:
- Authors: Nxele, Siphesihle R , Mashazi, Philani N , Nyokong, Tebello
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/189296 , vital:44835 , xlink:href="https://doi.org/10.1002/elan.201500212"
- Description: In this work, tetrakis(5-hexyn-oxy)Fe(II) phthalocyanine was synthesised in order to perform a click reaction between the terminal alkyne groups and an azide group on a glassy carbon electrode (GCE) surface. An azide group was formed on the electrode surface following electrografting using 4-azidobenzene diazonium tetrafluoroborate by electrochemical reduction. The Cu(I) catalyzed alkyne-azide Huisgen cycloaddition reaction was then employed in order to react the terminal alkyne groups on the phthalocyanine with the azide groups on the GCE surface. The modified electrode was employed to catalyse the oxidation of hydrazine. The electrode showed good electrocatalytic ability towards the detection of hydrazine with a sensitivity of 15.38 µA mM−1 and a limit of detection of 1.09 µM.
- Full Text:
Electrode surface modification using metallophthalocyanines and metal nanoparticles : electrocatalytic activity
- Authors: Maringa, Audacity
- Date: 2015
- Subjects: Phthalocyanines , Nanoparticles , Electrocatalysis , Scanning electron microscopy , X-ray photoelectron spectroscopy , Electrochemistry , Scanning electrochemical microscopy
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4541 , http://hdl.handle.net/10962/d1017921
- Description: Metallophthalocyanines and metal nanoparticles were successfully synthesized and applied for the electrooxidation of amitrole, nitrite and hydrazine individually or when employed together. The synthesized materials were characterized using the following techniques: predominantly scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), electrochemistry and scanning electrochemical microscopy (SECM). Different electrode modification methods were used to modify the glassy carbon substrates. The methods include adsorption, electrodeposition, electropolymerization and click chemistry. Modifying the glassy carbon substrate with MPc (electropolymerization) followed by metal nanoparticles (electrodeposition) or vice versa, made a hybrid modified surface that had efficient electron transfer. This was confirmed by electrochemical impedance studies with voltammetry measurements having lower detection potentials for the analytes. This work also describes for the first time the micropatterning of the glassy carbon substrate using the SECM tip. The substrate was electrografted with 4-azidobenzenediazonium salt and then the click reaction was performed using ethynylferrocene facilitated by Cu⁺ produced at the SECM tip. The SECM imaging was then used to show the clicked spot.
- Full Text:
- Authors: Maringa, Audacity
- Date: 2015
- Subjects: Phthalocyanines , Nanoparticles , Electrocatalysis , Scanning electron microscopy , X-ray photoelectron spectroscopy , Electrochemistry , Scanning electrochemical microscopy
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4541 , http://hdl.handle.net/10962/d1017921
- Description: Metallophthalocyanines and metal nanoparticles were successfully synthesized and applied for the electrooxidation of amitrole, nitrite and hydrazine individually or when employed together. The synthesized materials were characterized using the following techniques: predominantly scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), electrochemistry and scanning electrochemical microscopy (SECM). Different electrode modification methods were used to modify the glassy carbon substrates. The methods include adsorption, electrodeposition, electropolymerization and click chemistry. Modifying the glassy carbon substrate with MPc (electropolymerization) followed by metal nanoparticles (electrodeposition) or vice versa, made a hybrid modified surface that had efficient electron transfer. This was confirmed by electrochemical impedance studies with voltammetry measurements having lower detection potentials for the analytes. This work also describes for the first time the micropatterning of the glassy carbon substrate using the SECM tip. The substrate was electrografted with 4-azidobenzenediazonium salt and then the click reaction was performed using ethynylferrocene facilitated by Cu⁺ produced at the SECM tip. The SECM imaging was then used to show the clicked spot.
- Full Text:
Eliciting and combining expert opinion : an overview and comparison of methods
- Authors: Chinyamakobvu, Mutsa Carole
- Date: 2015
- Subjects: Decision making -- Statistical methods , Expertise , Bayesian statistical decision theory , Statistical decision , Delphi method , Paired comparisons (Statistics)
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5579 , http://hdl.handle.net/10962/d1017827
- Description: Decision makers have long relied on experts to inform their decision making. Expert judgment analysis is a way to elicit and combine the opinions of a group of experts to facilitate decision making. The use of expert judgment is most appropriate when there is a lack of data for obtaining reasonable statistical results. The experts are asked for advice by one or more decision makers who face a specific real decision problem. The decision makers are outside the group of experts and are jointly responsible and accountable for the decision and committed to finding solutions that everyone can live with. The emphasis is on the decision makers learning from the experts. The focus of this thesis is an overview and comparison of the various elicitation and combination methods available. These include the traditional committee method, the Delphi method, the paired comparisons method, the negative exponential model, Cooke’s classical model, the histogram technique, using the Dirichlet distribution in the case of a set of uncertain proportions which must sum to one, and the employment of overfitting. The supra Bayes approach, the determination of weights for the experts, and combining the opinions of experts where each opinion is associated with a confidence level that represents the expert’s conviction of his own judgment are also considered.
- Full Text:
- Authors: Chinyamakobvu, Mutsa Carole
- Date: 2015
- Subjects: Decision making -- Statistical methods , Expertise , Bayesian statistical decision theory , Statistical decision , Delphi method , Paired comparisons (Statistics)
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5579 , http://hdl.handle.net/10962/d1017827
- Description: Decision makers have long relied on experts to inform their decision making. Expert judgment analysis is a way to elicit and combine the opinions of a group of experts to facilitate decision making. The use of expert judgment is most appropriate when there is a lack of data for obtaining reasonable statistical results. The experts are asked for advice by one or more decision makers who face a specific real decision problem. The decision makers are outside the group of experts and are jointly responsible and accountable for the decision and committed to finding solutions that everyone can live with. The emphasis is on the decision makers learning from the experts. The focus of this thesis is an overview and comparison of the various elicitation and combination methods available. These include the traditional committee method, the Delphi method, the paired comparisons method, the negative exponential model, Cooke’s classical model, the histogram technique, using the Dirichlet distribution in the case of a set of uncertain proportions which must sum to one, and the employment of overfitting. The supra Bayes approach, the determination of weights for the experts, and combining the opinions of experts where each opinion is associated with a confidence level that represents the expert’s conviction of his own judgment are also considered.
- Full Text:
Employing safe bets: reflections on attracting, developing and retaining the next generation of academics
- Authors: Hlengwa, Amanda I
- Date: 2015
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10962/142145 , vital:38053 , ISBN 9781869142902 , https://books.google.co.za/books?id=49o8rgEACAAJanddq=Being+at+home:+Race,+institutional+culture+and+transformation+at+South+African+higher+education+institutionandhl=enandsa=Xandved=0ahUKEwiPgsa6mpjjAhXNN8AKHbNwAtoQ6AEIKDAA
- Description: This edited work has gathered together contributions on how to transform universities in South Africa; as many are struggling to shift their institutional culture. In a South African context, transformation means to attempt to change higher education institutions such that they no longer reflect the values promoted by apartheid but rather reflect the values embodied in South Africa's 1996 Constitution. Institutional culture is the main subject for discussion in this book. In order to transform South Africa's universities, the contributors begin by analyzing the idea of what a university is, and relatedly, what its ideal aims are. A second theme is to understand what institutional culture is and how it functions. Moreover, transformation cannot occur without transforming the broader cultures of which they are a part. Related to this theme is a general concern about how contemporary moves towards the instrumentalization of higher education affect the ability to transform institutions. These institutions are being pushed to conform to goals that are outside the traditional idea of a university, such as concerns that universities are being 'bureaucratized' and becoming corporations, instead of a place of learning open to all. In conclusion it can be said that the contemporary South African academic community has an opportunity to recreate itself as the end of apartheid created space for engaging in transformative epistemic projects. The transformation of the tertiary sector entails a transformation of institutional cultures.
- Full Text:
- Authors: Hlengwa, Amanda I
- Date: 2015
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10962/142145 , vital:38053 , ISBN 9781869142902 , https://books.google.co.za/books?id=49o8rgEACAAJanddq=Being+at+home:+Race,+institutional+culture+and+transformation+at+South+African+higher+education+institutionandhl=enandsa=Xandved=0ahUKEwiPgsa6mpjjAhXNN8AKHbNwAtoQ6AEIKDAA
- Description: This edited work has gathered together contributions on how to transform universities in South Africa; as many are struggling to shift their institutional culture. In a South African context, transformation means to attempt to change higher education institutions such that they no longer reflect the values promoted by apartheid but rather reflect the values embodied in South Africa's 1996 Constitution. Institutional culture is the main subject for discussion in this book. In order to transform South Africa's universities, the contributors begin by analyzing the idea of what a university is, and relatedly, what its ideal aims are. A second theme is to understand what institutional culture is and how it functions. Moreover, transformation cannot occur without transforming the broader cultures of which they are a part. Related to this theme is a general concern about how contemporary moves towards the instrumentalization of higher education affect the ability to transform institutions. These institutions are being pushed to conform to goals that are outside the traditional idea of a university, such as concerns that universities are being 'bureaucratized' and becoming corporations, instead of a place of learning open to all. In conclusion it can be said that the contemporary South African academic community has an opportunity to recreate itself as the end of apartheid created space for engaging in transformative epistemic projects. The transformation of the tertiary sector entails a transformation of institutional cultures.
- Full Text:
Encouraging individual retirement savings in South Africa
- Authors: Hirschbeck, Lisa
- Date: 2015
- Subjects: Retirement income -- Planning-- South Africa , Retirement income -- Government policy -- South Africa , Pension trusts -- South Africa -- Management , Pension trusts -- Termination -- Law and legislation -- South Africa , Income tax deductions for retirement contributions -- South Africa
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:913 , http://hdl.handle.net/10962/d1017535
- Description: Many South Africans may not have adequate retirement savings when they retire and this has the effect of a low income replacement ratio on retirement that may lead to a decrease in the standard of living of the retiree and in extreme cases the retiree becoming dependent on their family and the government. Owing to this trend of no or inadequate retirement savings, South Africa embarked on a retirement reform journey in 2004. The goal of this research is to determine whether the retirement reform mechanisms outlined by National Treasury would encourage individual retirement savings that should assist South Africans to achieve stability of income in their retirement. This research analysed the current retirement savings options and vehicles available for South Africans, the current tax incentives and disincentives and reviewed the proposed changes to tax incentives and disincentives during the accumulation phase of retirement savings and explained how these proposed tax incentives are harmonised for the accumulation phase of retirement. The research explained how National Treasury aims to limit pre-retirement withdrawals and how it intends to encourage the annuitisation of post-retirement benefits. The penultimate chapter of this research measured the effect (by making certain assumptions) of the changes proposed by National Treasury on the income replacement ratio of the retiree. Throughout the research comparisons were made between The OECD Roadmap for the good design of defined contribution pension plans and National Treasury’s proposals. This research did not directly address the effect of increased life expectancies on retirement savings or increases in youth unemployment and the effect that this may have on retirement savings. The effect of financial charges levied on retirement savings on the income replacement ratio of a retiree was also not explored. Furthermore, not all pension funds are regulated by the Pension Funds Act and how these pension funds can be brought within the purview of the Pension Funds Act was not investigated. Automatic enrolment of retirement savings for all employees in South Africa in retirement vehicles is a further research area that could be addressed.
- Full Text:
- Authors: Hirschbeck, Lisa
- Date: 2015
- Subjects: Retirement income -- Planning-- South Africa , Retirement income -- Government policy -- South Africa , Pension trusts -- South Africa -- Management , Pension trusts -- Termination -- Law and legislation -- South Africa , Income tax deductions for retirement contributions -- South Africa
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:913 , http://hdl.handle.net/10962/d1017535
- Description: Many South Africans may not have adequate retirement savings when they retire and this has the effect of a low income replacement ratio on retirement that may lead to a decrease in the standard of living of the retiree and in extreme cases the retiree becoming dependent on their family and the government. Owing to this trend of no or inadequate retirement savings, South Africa embarked on a retirement reform journey in 2004. The goal of this research is to determine whether the retirement reform mechanisms outlined by National Treasury would encourage individual retirement savings that should assist South Africans to achieve stability of income in their retirement. This research analysed the current retirement savings options and vehicles available for South Africans, the current tax incentives and disincentives and reviewed the proposed changes to tax incentives and disincentives during the accumulation phase of retirement savings and explained how these proposed tax incentives are harmonised for the accumulation phase of retirement. The research explained how National Treasury aims to limit pre-retirement withdrawals and how it intends to encourage the annuitisation of post-retirement benefits. The penultimate chapter of this research measured the effect (by making certain assumptions) of the changes proposed by National Treasury on the income replacement ratio of the retiree. Throughout the research comparisons were made between The OECD Roadmap for the good design of defined contribution pension plans and National Treasury’s proposals. This research did not directly address the effect of increased life expectancies on retirement savings or increases in youth unemployment and the effect that this may have on retirement savings. The effect of financial charges levied on retirement savings on the income replacement ratio of a retiree was also not explored. Furthermore, not all pension funds are regulated by the Pension Funds Act and how these pension funds can be brought within the purview of the Pension Funds Act was not investigated. Automatic enrolment of retirement savings for all employees in South Africa in retirement vehicles is a further research area that could be addressed.
- Full Text:
End of the march
- Authors: Thomas, Cornelius
- Date: 2015
- Language: English
- Type: still image
- Identifier: vital:7981 , http://hdl.handle.net/10962/d1020456
- Description: On Wednesday, 21 October 2015, Rhodes University closed in solidarity with the higher education sector as students and staff embarked on nationwide protest action against the shortage of funding in the South African higher education sector. #FeesMustFall is a national student led protest movement that began in mid-October 2015 in response to proposed increases in fees at South African universities. These images depict the peaceful march and illustrate the extent of solidarity among staff, students and community members who joined in support of the protest.
- Full Text: false
- Authors: Thomas, Cornelius
- Date: 2015
- Language: English
- Type: still image
- Identifier: vital:7981 , http://hdl.handle.net/10962/d1020456
- Description: On Wednesday, 21 October 2015, Rhodes University closed in solidarity with the higher education sector as students and staff embarked on nationwide protest action against the shortage of funding in the South African higher education sector. #FeesMustFall is a national student led protest movement that began in mid-October 2015 in response to proposed increases in fees at South African universities. These images depict the peaceful march and illustrate the extent of solidarity among staff, students and community members who joined in support of the protest.
- Full Text: false