Exploring differences between organisational cultures in a company undergoing change
- Authors: Bowa, Mabvuto
- Date: 2003
- Subjects: Organizational change -- Africa , Corporate culture -- Africa , Management -- Africa , Organizational behavior -- Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3126 , http://hdl.handle.net/10962/d1006287 , Organizational change -- Africa , Corporate culture -- Africa , Management -- Africa , Organizational behavior -- Africa
- Description: Change is a common phenomena in business organisations today. The turbulent environment is exerting a significant influence on organisations to make continuous changes in their internal environment in an attempt to improve performance and achieve competitiveness in the marketplace. The human factors which confront organisations undergoing change have not been thoroughly investigated in Sub-Saharan Africa. The present study aimed at investigating human issues affecting the performance ofan organisation located in an Afiican country. Data was collected using semi-structured interviews and focus groups. Twenty interviews were conducted with employees randomly selected from all the levels of the company, namely attendant, operator, supervisory, middle and top management. Five focus groups were carried out with employees from different employee categories. Both sets of data were analysed using grounded theory. The findings showed that there were several problems in the company including insecurity, lack of opportunities for employee development, autocratic management style, lack of participation in decision making, substandard performance, ineffective human resources systems and lack of adaptation to technology. It was suggested that the problems resulted from the clash between organisational cultures in the company. At one level, there was a clash between the local workers' socialist organisational culture and the expatriates' capitalistic organisational culture. At a more deeper level, the clash appeared to be between the local employees' collectivistic sociocultural values and the expatriates' individualistic value system. These findings have significant implications for managing change in organisations with diverse cultures.
- Full Text:
- Date Issued: 2003
- Authors: Bowa, Mabvuto
- Date: 2003
- Subjects: Organizational change -- Africa , Corporate culture -- Africa , Management -- Africa , Organizational behavior -- Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3126 , http://hdl.handle.net/10962/d1006287 , Organizational change -- Africa , Corporate culture -- Africa , Management -- Africa , Organizational behavior -- Africa
- Description: Change is a common phenomena in business organisations today. The turbulent environment is exerting a significant influence on organisations to make continuous changes in their internal environment in an attempt to improve performance and achieve competitiveness in the marketplace. The human factors which confront organisations undergoing change have not been thoroughly investigated in Sub-Saharan Africa. The present study aimed at investigating human issues affecting the performance ofan organisation located in an Afiican country. Data was collected using semi-structured interviews and focus groups. Twenty interviews were conducted with employees randomly selected from all the levels of the company, namely attendant, operator, supervisory, middle and top management. Five focus groups were carried out with employees from different employee categories. Both sets of data were analysed using grounded theory. The findings showed that there were several problems in the company including insecurity, lack of opportunities for employee development, autocratic management style, lack of participation in decision making, substandard performance, ineffective human resources systems and lack of adaptation to technology. It was suggested that the problems resulted from the clash between organisational cultures in the company. At one level, there was a clash between the local workers' socialist organisational culture and the expatriates' capitalistic organisational culture. At a more deeper level, the clash appeared to be between the local employees' collectivistic sociocultural values and the expatriates' individualistic value system. These findings have significant implications for managing change in organisations with diverse cultures.
- Full Text:
- Date Issued: 2003
External and domestic sources of foreign policy ambiguity: South African foreign policy and the projection of pluralist middle power
- Authors: Bischoff, Paul, 1954-
- Date: 2003
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/161442 , vital:40627 , https://doi.org/10.1080/0258934032000147291
- Description: As a pluralist middle power, post-apartheid South Africa seeks to generate successful foreign policy initiatives at bilateral, multilateral and regional levels in order to shape international outcomes. In this endeavour, it has three important political resources – a recognition of its geo-political position and importance as a democratic yardstick and reformer; its acceptance of a transnational, neo-liberal elite alliance and finally, recognition of its leadership role from forces wishing to challenge African political establishments. However, the international and domestic political environment which in the mid-1990s was favourable towards middle-power initiative and reform has narrowed.
- Full Text:
- Date Issued: 2003
- Authors: Bischoff, Paul, 1954-
- Date: 2003
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/161442 , vital:40627 , https://doi.org/10.1080/0258934032000147291
- Description: As a pluralist middle power, post-apartheid South Africa seeks to generate successful foreign policy initiatives at bilateral, multilateral and regional levels in order to shape international outcomes. In this endeavour, it has three important political resources – a recognition of its geo-political position and importance as a democratic yardstick and reformer; its acceptance of a transnational, neo-liberal elite alliance and finally, recognition of its leadership role from forces wishing to challenge African political establishments. However, the international and domestic political environment which in the mid-1990s was favourable towards middle-power initiative and reform has narrowed.
- Full Text:
- Date Issued: 2003
Finite element modelling of a magma chamber surrounded by country-rock, with particular reference to the groundwater flow in sections of different permeability
- Authors: Remsing, Carmen
- Date: 2003 , 2013-05-23
- Subjects: Magmas , Groundwater flow
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5508 , http://hdl.handle.net/10962/d1007537 , Magmas , Groundwater flow
- Description: This thesis presents results of two-dimensional finite element modelling of a magma chamber surrounded by country-rock containing a section of high permeability. The high permeability section in the country-rock simulates structure that is predominant in controlling the groundwater convection pattern and resulting mineral deposits. The models have analogies in nature: for instance the gold mines in the Massif Central of France, the Pogo mine in Alaska and the Pilgrim's Rest gold field in South Africa. This is a complicated coupled system involving fluid flow and heat transfer under extreme conditions. The magma in the chamber convects and as it cools the heat liberated causes convection in the groundwater contained in the surrounding country-rock. This convection in turn affects the rate of liberation of heat from the magma. The software used for the modelling, FLOTRAN, is the computational fluid dynamics component of the commercial ANSYS package. The results obtained describe in detail the flow pattern in the magma chamber, the country-rock and high permeability section thereof. During the cooling of the magma chamber the groundwater convects more vigorously in the high permeability section than elsewhere, and a convection cell is seen forming within this region. This provides a mechanism for hydrothermal formation of valuable mineral deposits in the structure near a magma chamber. It is found that the relationship between the velocity of the flow in the cell and the temperature of the magma chamber is well represented by a first order linear differential equation, providing a simple understanding of this process, , KMBT_363 , Adobe Acrobat 9.54 Paper Capture Plug-in
- Full Text:
- Date Issued: 2003
- Authors: Remsing, Carmen
- Date: 2003 , 2013-05-23
- Subjects: Magmas , Groundwater flow
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5508 , http://hdl.handle.net/10962/d1007537 , Magmas , Groundwater flow
- Description: This thesis presents results of two-dimensional finite element modelling of a magma chamber surrounded by country-rock containing a section of high permeability. The high permeability section in the country-rock simulates structure that is predominant in controlling the groundwater convection pattern and resulting mineral deposits. The models have analogies in nature: for instance the gold mines in the Massif Central of France, the Pogo mine in Alaska and the Pilgrim's Rest gold field in South Africa. This is a complicated coupled system involving fluid flow and heat transfer under extreme conditions. The magma in the chamber convects and as it cools the heat liberated causes convection in the groundwater contained in the surrounding country-rock. This convection in turn affects the rate of liberation of heat from the magma. The software used for the modelling, FLOTRAN, is the computational fluid dynamics component of the commercial ANSYS package. The results obtained describe in detail the flow pattern in the magma chamber, the country-rock and high permeability section thereof. During the cooling of the magma chamber the groundwater convects more vigorously in the high permeability section than elsewhere, and a convection cell is seen forming within this region. This provides a mechanism for hydrothermal formation of valuable mineral deposits in the structure near a magma chamber. It is found that the relationship between the velocity of the flow in the cell and the temperature of the magma chamber is well represented by a first order linear differential equation, providing a simple understanding of this process, , KMBT_363 , Adobe Acrobat 9.54 Paper Capture Plug-in
- Full Text:
- Date Issued: 2003
Foam drug delivery in dermatology: beyond the scalp
- Purdon, Carryn H, Haigh, John M, Surber, Christian, Smith, Eric W
- Authors: Purdon, Carryn H , Haigh, John M , Surber, Christian , Smith, Eric W
- Date: 2003
- Subjects: Adis International Limited , Drug delivery systems , Skin disorders
- Language: English
- Type: text , Article
- Identifier: vital:6418 , http://hdl.handle.net/10962/d1006541
- Description: Consumers of topical formulations apply a wide spectrum of preparations, both cosmetic and dermatological, to their healthy or diseased skin. These formulations range in physicochemical nature from solid through semisolid to liquid. Pharmaceutical foams are pressurized dosage forms containing one or more active ingredients that, upon valve actuation, emit a fine dispersion of liquid and/or solid materials in a gaseous medium. Foam formulations are generally easier to apply, are less dense, and spread more easily than other topical dosage forms. Foams may be formulated in various ways to provide emollient or drying functions to the skin, depending on the formulation constituents. Therefore, this delivery technology should be a useful addition to the spectrum of formulations available for topical use; however, as yet, only a few are commercially available. Probably the most convincing argument for the use of foams is ease of use by the patient, and consumer acceptance. Most foam dosage forms used in dermatology to date have incorporated corticosteroids, although some products have also been used to deliver antiseptics, antifungal agents, anti-inflammatory agents, local anesthetic agents, skin emollients, and protectants. Although there is no clinical evidence that foam formulations are currently superior to other conventional delivery vehicles, these formulations have a clear application advantage and with continued developments in the science of supersaturation technology, it seems certain that foam delivery systems will retain their place in the dermatological and cosmetic armamentarium.
- Full Text:
- Date Issued: 2003
- Authors: Purdon, Carryn H , Haigh, John M , Surber, Christian , Smith, Eric W
- Date: 2003
- Subjects: Adis International Limited , Drug delivery systems , Skin disorders
- Language: English
- Type: text , Article
- Identifier: vital:6418 , http://hdl.handle.net/10962/d1006541
- Description: Consumers of topical formulations apply a wide spectrum of preparations, both cosmetic and dermatological, to their healthy or diseased skin. These formulations range in physicochemical nature from solid through semisolid to liquid. Pharmaceutical foams are pressurized dosage forms containing one or more active ingredients that, upon valve actuation, emit a fine dispersion of liquid and/or solid materials in a gaseous medium. Foam formulations are generally easier to apply, are less dense, and spread more easily than other topical dosage forms. Foams may be formulated in various ways to provide emollient or drying functions to the skin, depending on the formulation constituents. Therefore, this delivery technology should be a useful addition to the spectrum of formulations available for topical use; however, as yet, only a few are commercially available. Probably the most convincing argument for the use of foams is ease of use by the patient, and consumer acceptance. Most foam dosage forms used in dermatology to date have incorporated corticosteroids, although some products have also been used to deliver antiseptics, antifungal agents, anti-inflammatory agents, local anesthetic agents, skin emollients, and protectants. Although there is no clinical evidence that foam formulations are currently superior to other conventional delivery vehicles, these formulations have a clear application advantage and with continued developments in the science of supersaturation technology, it seems certain that foam delivery systems will retain their place in the dermatological and cosmetic armamentarium.
- Full Text:
- Date Issued: 2003
Food choices of tactile defensive children
- Authors: Smith, Anna Magdalena
- Date: 2003
- Subjects: Children -- Nutrition -- Psychological aspects
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:11034 , http://hdl.handle.net/10948/d1020371
- Description: This research explores a different view of the picky or fussy eater. Although occupational therapists and speech therapists are aware that children with sensory defensiveness and specific tactile defensiveness have different eating habits, this has not been described before.
- Full Text:
- Date Issued: 2003
- Authors: Smith, Anna Magdalena
- Date: 2003
- Subjects: Children -- Nutrition -- Psychological aspects
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:11034 , http://hdl.handle.net/10948/d1020371
- Description: This research explores a different view of the picky or fussy eater. Although occupational therapists and speech therapists are aware that children with sensory defensiveness and specific tactile defensiveness have different eating habits, this has not been described before.
- Full Text:
- Date Issued: 2003
From labour reserve to investment opportunity: economic development planning in the Mbashe Local Municipal area in the Eastern Cape
- Authors: Reynolds, John Hunter
- Date: 2003
- Subjects: Economic development -- South Africa -- Eastern Cape , Community development -- South Africa -- Eastern Cape , South Africa -- Economic policy , Planning -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSocSc
- Identifier: vital:3353 , http://hdl.handle.net/10962/d1007490 , Economic development -- South Africa -- Eastern Cape , Community development -- South Africa -- Eastern Cape , South Africa -- Economic policy , Planning -- South Africa -- Eastern Cape
- Description: Planning for economic development at the local level has become increasingly important in many countries of the world. South Africa is no exception and has had the local focus entrenched through constitutional provisions for developmental local government. This developmental approach has been intimately linked to, and influenced by, the broader legislative, policy and planning context within which the development challenges of post-Apartheid South Africa have been addressed. It has also been implemented in a context of far-reaching transformation of public institutions aimed, in the final analysis, at the effective functioning of three spheres of government. In this thesis, the Mbashe Local Municipal area is used as a case study for an examination of the linkages between economic development planning at the local, provincial and national levels. It is not a case study in the sense that an in-depth analysis of practice is undertaken; it is used rather as a lens through which the economic development planning activities of the three spheres of government are viewed. Its value as a lens lies in its location in the former Transkei, which is characterised by high levels of unemployment and poverty and low levels of service infrastructure, and in its status as one of the newly demarcated local municipalities in South Africa. Mbashe is a pilot site of the Promotion of Rural Livelihoods Programme, which has been linked to the Eastern Cape Province's Integrated Sustainable Rural Development Programme. It also includes one of the nodes of the Wild Coast Spatial Development Initiative, which has, since 1998, been promoted as a vehicle for economic development in the former Transkei. Research comprised extensive documentary research, individual interviews with key role players in the Mbashe Local Municipality, the Promotion of Rural Livelihoods Programme and the Wild Coast Spatial Development Initiative, and a group interview with members of the Local Economic Development Sub-Committee of the Mbashe Local Municipal Council. An attempt was made to understand the complex layers of policy and planning frameworks that guide planning at the national and provincial levels and within which local level economic development is situated, and to explore the responses that have been forged by agents within the Mbashe area. Key in this endeavour has been the initiatives developed under the guidance of the Mbashe Local Economic Development Sub-Committee. It is argued that the severe resource constraints faced within Mbashe, combined with limited knowledge of and participation in larger planning and resource mobilisation frameworks, lock Local Economic Development within the top-down and investmentled approaches, rather than the more integrated approach that is promoted in terms of legislation and that is required if poverty is to be addressed successfully. The limitations on state fiscal expenditure and the market-led approach to service provision and economic development, implemented in terms of South Africa's macroeconomic framework, combined with limited synchronisation of planning cycles in which integrated development planning at the local level is privileged, leave little scope for endogenous economic development at local level. There is scope for creative engagement with the interlocking local, provincial, national and continental economies by actively shifting resources in support of integrated, endogenous approaches. Such approaches could serve as counter-narratives to the dominance of neoliberalism and allow for the establishment of local economic development practice that addresses the needs of the poor and that builds integrated local economies under the control of democratic institutions. It is only with such a shifting of approach that economic development within Mbashe will shift the structural conditions that lock it into economic dependence and poverty.
- Full Text:
- Date Issued: 2003
- Authors: Reynolds, John Hunter
- Date: 2003
- Subjects: Economic development -- South Africa -- Eastern Cape , Community development -- South Africa -- Eastern Cape , South Africa -- Economic policy , Planning -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSocSc
- Identifier: vital:3353 , http://hdl.handle.net/10962/d1007490 , Economic development -- South Africa -- Eastern Cape , Community development -- South Africa -- Eastern Cape , South Africa -- Economic policy , Planning -- South Africa -- Eastern Cape
- Description: Planning for economic development at the local level has become increasingly important in many countries of the world. South Africa is no exception and has had the local focus entrenched through constitutional provisions for developmental local government. This developmental approach has been intimately linked to, and influenced by, the broader legislative, policy and planning context within which the development challenges of post-Apartheid South Africa have been addressed. It has also been implemented in a context of far-reaching transformation of public institutions aimed, in the final analysis, at the effective functioning of three spheres of government. In this thesis, the Mbashe Local Municipal area is used as a case study for an examination of the linkages between economic development planning at the local, provincial and national levels. It is not a case study in the sense that an in-depth analysis of practice is undertaken; it is used rather as a lens through which the economic development planning activities of the three spheres of government are viewed. Its value as a lens lies in its location in the former Transkei, which is characterised by high levels of unemployment and poverty and low levels of service infrastructure, and in its status as one of the newly demarcated local municipalities in South Africa. Mbashe is a pilot site of the Promotion of Rural Livelihoods Programme, which has been linked to the Eastern Cape Province's Integrated Sustainable Rural Development Programme. It also includes one of the nodes of the Wild Coast Spatial Development Initiative, which has, since 1998, been promoted as a vehicle for economic development in the former Transkei. Research comprised extensive documentary research, individual interviews with key role players in the Mbashe Local Municipality, the Promotion of Rural Livelihoods Programme and the Wild Coast Spatial Development Initiative, and a group interview with members of the Local Economic Development Sub-Committee of the Mbashe Local Municipal Council. An attempt was made to understand the complex layers of policy and planning frameworks that guide planning at the national and provincial levels and within which local level economic development is situated, and to explore the responses that have been forged by agents within the Mbashe area. Key in this endeavour has been the initiatives developed under the guidance of the Mbashe Local Economic Development Sub-Committee. It is argued that the severe resource constraints faced within Mbashe, combined with limited knowledge of and participation in larger planning and resource mobilisation frameworks, lock Local Economic Development within the top-down and investmentled approaches, rather than the more integrated approach that is promoted in terms of legislation and that is required if poverty is to be addressed successfully. The limitations on state fiscal expenditure and the market-led approach to service provision and economic development, implemented in terms of South Africa's macroeconomic framework, combined with limited synchronisation of planning cycles in which integrated development planning at the local level is privileged, leave little scope for endogenous economic development at local level. There is scope for creative engagement with the interlocking local, provincial, national and continental economies by actively shifting resources in support of integrated, endogenous approaches. Such approaches could serve as counter-narratives to the dominance of neoliberalism and allow for the establishment of local economic development practice that addresses the needs of the poor and that builds integrated local economies under the control of democratic institutions. It is only with such a shifting of approach that economic development within Mbashe will shift the structural conditions that lock it into economic dependence and poverty.
- Full Text:
- Date Issued: 2003
Fuelwood availability and use in the Richtersveld National Park, South Africa
- Shackleton, Charlie M, Guthrie, G, Keirungi, J, Stewart, J
- Authors: Shackleton, Charlie M , Guthrie, G , Keirungi, J , Stewart, J
- Date: 2003
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/181461 , vital:43736 , xlink:href=" https://doi.org/10.4102/koedoe.v46i2.66"
- Description: Concern has been voiced about the possible over-use of fuelwood from the riparian fringe by pastoralist herders in the Richtersveld National Park (RNP). This coincided with the current examination and modelling of the supply and use of ecosystem goods and services in the Gariep Basin as part of the Southern African Millennium Assessment (SAfMA). This paper reports on a study to index the current availability of deadwood within the riparian zone of RNP, its relationship with proximity to human habitation, and species preferences of the local herders. Deadwood availability was assessed per woody species and on the ground in 12 transects within the riparian fringe. Herders were interviewed regarding their species preferences, and the composition of woodpiles was examined. There was no relationship between the percentage of attached deadwood on the tree, or the percentage deadwood ground cover, and the distance from herder stockposts. Euclea pseudobenus and Tamarix usneoides were the dominant species in the riparian fringe. There was strong selection for Ziziphus mucronata as a fuelwood species and only marginal or random selection for E. pseudobenus. Tamarix usneoides and Prosopis sp. were abundant in the riparian zone, but were not used for fuelwood. There was a significant difference between species with respect to the mean proportion of the stem that was dead, the highest being Z. mucronata (± 28 % deadwood), followed by T. usneoides (± 12 %). Most of the Prosopis trees had no deadwood. Across all species, the mean percentage dead per tree was approximately 15 %. Additionally, detached deadwood covered just less than 9 % of ground area, averaged across all plots and transects. All the variables measured indicated that there seems to be little need for concern over the current fuelwood extraction activities of pastoralists within the RNP. There was no clear evidence of cutting of branches or deadwood. The abundance of both attached and detached deadwood was not depleted close to human habitation. There was still abundant deadwood, even on preferred species. The most preferred species (Ziziphus mucronata) had the greatest mean proportion of deadwood. The herders stated that they only used deadwood, and that there was plenty. They rarely used driftwood washed down the river, although there was an abundance of it. Thus, overall, there was no sign of depletion of the deadwood resource, even on favoured species, or degradation of the productive capacity for deadwood.
- Full Text:
- Date Issued: 2003
- Authors: Shackleton, Charlie M , Guthrie, G , Keirungi, J , Stewart, J
- Date: 2003
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/181461 , vital:43736 , xlink:href=" https://doi.org/10.4102/koedoe.v46i2.66"
- Description: Concern has been voiced about the possible over-use of fuelwood from the riparian fringe by pastoralist herders in the Richtersveld National Park (RNP). This coincided with the current examination and modelling of the supply and use of ecosystem goods and services in the Gariep Basin as part of the Southern African Millennium Assessment (SAfMA). This paper reports on a study to index the current availability of deadwood within the riparian zone of RNP, its relationship with proximity to human habitation, and species preferences of the local herders. Deadwood availability was assessed per woody species and on the ground in 12 transects within the riparian fringe. Herders were interviewed regarding their species preferences, and the composition of woodpiles was examined. There was no relationship between the percentage of attached deadwood on the tree, or the percentage deadwood ground cover, and the distance from herder stockposts. Euclea pseudobenus and Tamarix usneoides were the dominant species in the riparian fringe. There was strong selection for Ziziphus mucronata as a fuelwood species and only marginal or random selection for E. pseudobenus. Tamarix usneoides and Prosopis sp. were abundant in the riparian zone, but were not used for fuelwood. There was a significant difference between species with respect to the mean proportion of the stem that was dead, the highest being Z. mucronata (± 28 % deadwood), followed by T. usneoides (± 12 %). Most of the Prosopis trees had no deadwood. Across all species, the mean percentage dead per tree was approximately 15 %. Additionally, detached deadwood covered just less than 9 % of ground area, averaged across all plots and transects. All the variables measured indicated that there seems to be little need for concern over the current fuelwood extraction activities of pastoralists within the RNP. There was no clear evidence of cutting of branches or deadwood. The abundance of both attached and detached deadwood was not depleted close to human habitation. There was still abundant deadwood, even on preferred species. The most preferred species (Ziziphus mucronata) had the greatest mean proportion of deadwood. The herders stated that they only used deadwood, and that there was plenty. They rarely used driftwood washed down the river, although there was an abundance of it. Thus, overall, there was no sign of depletion of the deadwood resource, even on favoured species, or degradation of the productive capacity for deadwood.
- Full Text:
- Date Issued: 2003
Genetic variation within two pulmonate limpet species, Siphonaria capensis and S. serrata along the South African coast
- Authors: Seaman, Jennifer Ann
- Date: 2003
- Subjects: Limpets -- South Africa Pulmonata Siphonaria Limpets -- Genetics
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5800 , http://hdl.handle.net/10962/d1006155
- Description: Dispersal rates are known to play a fundamental role in establishing the genetic structure found within a species. Dispersal in marine benthic invertebrates is largely dependent on life history strategy. The presence of pelagic larvae will potentially result in high dispersal within a species, while direct development limits dispersal. This study used two intertidal pulmonate limpet species to investigate the relationship between dispersal potential and genetic structure of populations. Siphonaria capensis produces benthic egg masses, which release pelagic larvae. These float in ocean currents before settling and metamorphosing into adults. S. serrata reproduces by direct development. The larvae hatch as completely metamorphosed juveniles after developing in an egg case not far from the parent. The high dispersal capacity of S. capensis pelagic larvae should result in high levels of within-population variation since individuals within a particular population may originate from several different populations. This should lead to high levels of gene flow along the coast and to low genetic differentiation among populations. On the other hand, the low dispersal potential of S. serrata should cause low levels of genetic variation within populations, as relatives will remain close to one another. Low levels of gene flow and high genetic differentiation among populations are expected in this species. In dealing with the relationship between life history strategy and population genetic structure in these two species, a series of indirect techniques was utilised. Multivariate analyses of the morphological variation within each species showed that variation in size was similar between the two species and largely governed by environmental factors. Variation in shell shape was largely under genetic control and supported the predictions made for each species. Variation in total proteins was relatively uninformative in terms of examining the differences between the two species. Allozyme analysis and mtDNA sequencing clearly showed differences between the species in terms of their population genetic structure. High levels of gene flow were found within S. capensis. This was strongly influenced by ocean currents, with the close inshore Agulhas current along the Transkei coast contributing to high levels of dispersal and hence gene flow. Low levels of gene flow occurred within S. serrata, resulting in low within-population variation and high among-population differentiation.
- Full Text:
- Date Issued: 2003
- Authors: Seaman, Jennifer Ann
- Date: 2003
- Subjects: Limpets -- South Africa Pulmonata Siphonaria Limpets -- Genetics
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5800 , http://hdl.handle.net/10962/d1006155
- Description: Dispersal rates are known to play a fundamental role in establishing the genetic structure found within a species. Dispersal in marine benthic invertebrates is largely dependent on life history strategy. The presence of pelagic larvae will potentially result in high dispersal within a species, while direct development limits dispersal. This study used two intertidal pulmonate limpet species to investigate the relationship between dispersal potential and genetic structure of populations. Siphonaria capensis produces benthic egg masses, which release pelagic larvae. These float in ocean currents before settling and metamorphosing into adults. S. serrata reproduces by direct development. The larvae hatch as completely metamorphosed juveniles after developing in an egg case not far from the parent. The high dispersal capacity of S. capensis pelagic larvae should result in high levels of within-population variation since individuals within a particular population may originate from several different populations. This should lead to high levels of gene flow along the coast and to low genetic differentiation among populations. On the other hand, the low dispersal potential of S. serrata should cause low levels of genetic variation within populations, as relatives will remain close to one another. Low levels of gene flow and high genetic differentiation among populations are expected in this species. In dealing with the relationship between life history strategy and population genetic structure in these two species, a series of indirect techniques was utilised. Multivariate analyses of the morphological variation within each species showed that variation in size was similar between the two species and largely governed by environmental factors. Variation in shell shape was largely under genetic control and supported the predictions made for each species. Variation in total proteins was relatively uninformative in terms of examining the differences between the two species. Allozyme analysis and mtDNA sequencing clearly showed differences between the species in terms of their population genetic structure. High levels of gene flow were found within S. capensis. This was strongly influenced by ocean currents, with the close inshore Agulhas current along the Transkei coast contributing to high levels of dispersal and hence gene flow. Low levels of gene flow occurred within S. serrata, resulting in low within-population variation and high among-population differentiation.
- Full Text:
- Date Issued: 2003
Geographical races of the honeybees (Apis Mellifera L.) of the Northern regions of Ethiopia
- Authors: Mohammed, Nuru Adgaba
- Date: 2003
- Subjects: Honeybee -- Ethiopia Honeybee -- Behavior -- Ethiopia Honeybee -- Ethiopia -- Morphology Honeybee -- Ecology -- Ethiopia
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5827 , http://hdl.handle.net/10962/d1007671
- Description: The ideal climatic conditions and diversity of floral resources allow Ethiopia to sustain millions of honeybee colonies. Beekeeping is widely practiced and plays a significant role in the livelihood of the farming community of the country. Despite this, information on the types of geographical races of honeybees, their behavioural characters and the related ecological factors are not established. In this work an attempt was made to characterise the honeybee populations of the northern parts of Ethiopia based on the analyses of morphological, behavioural and ecological characteristics. For morphological analysis, 155 honeybee colony samples from 31 localities were collected. 20 worker honeybees per colony sample totalled 3100 individual worker honeybees and thirteen morphological characters per bee, a total of 40 300 measurements were recorded following Ruttner's (1988) protocols. The behavioural characters such as reproductive swarming, migration, temperament and colony seasonal cycles were assessed based on survey work of a pre-structured questionnaire. Various univariate and multivariate statistical methods were employed to analyse the data. The principal components and step-wise linear discriminant analyses revealed the existence of four discrete morphoclusters or geographical races: A. m. jemenitica from eastern, northwestern and northern arid and semi-arid lowlands, A. m. scutellata from the western humid midlands, A. m. bandasii from sub-moist central highlands and A. m. monticola from the northern mountainous parts of the study areas. These different geographical races were found to be distinctively distributed in the different ecological parts of the study area. High intercolonial and intracolonial variances were observed in all localities, however particularly high values were obtained in areas of transitions between ecological zones indicating a region of gene flow or zones of hybridisation among the statistically defined populations. Such high variances were observed mostly in areas where A. m. jemenitica borders the other geographical races. Moreover. distinct behavioural variations were also noted among these geographical races. Generally. the highland and mountainous honeybees A. m. bandasii and A. m. monticola are relatively larger in body size. have less tendency to swarm. less inclination to migrate and are relatively gentle while the converse traits were noted for the lowlands and midlands honeybees A. m. jemenitica and A. m. scutellata. Both morphological and behavioural variations were highly correlated with environmental factors and the variations seem to be the result of long adaptation to the interrelated ecological factors in their respective areas. Variations in reproductive swarming periods were also noted among these honeybee populations as a result of variations in rainfall pattern. altitude and temperature in their respective ecological areas which are believed to alter the honeybee colonies' seasonal cycles and leads to partial temporal reproductive isolation among these different honeybee populations.
- Full Text:
- Date Issued: 2003
- Authors: Mohammed, Nuru Adgaba
- Date: 2003
- Subjects: Honeybee -- Ethiopia Honeybee -- Behavior -- Ethiopia Honeybee -- Ethiopia -- Morphology Honeybee -- Ecology -- Ethiopia
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5827 , http://hdl.handle.net/10962/d1007671
- Description: The ideal climatic conditions and diversity of floral resources allow Ethiopia to sustain millions of honeybee colonies. Beekeeping is widely practiced and plays a significant role in the livelihood of the farming community of the country. Despite this, information on the types of geographical races of honeybees, their behavioural characters and the related ecological factors are not established. In this work an attempt was made to characterise the honeybee populations of the northern parts of Ethiopia based on the analyses of morphological, behavioural and ecological characteristics. For morphological analysis, 155 honeybee colony samples from 31 localities were collected. 20 worker honeybees per colony sample totalled 3100 individual worker honeybees and thirteen morphological characters per bee, a total of 40 300 measurements were recorded following Ruttner's (1988) protocols. The behavioural characters such as reproductive swarming, migration, temperament and colony seasonal cycles were assessed based on survey work of a pre-structured questionnaire. Various univariate and multivariate statistical methods were employed to analyse the data. The principal components and step-wise linear discriminant analyses revealed the existence of four discrete morphoclusters or geographical races: A. m. jemenitica from eastern, northwestern and northern arid and semi-arid lowlands, A. m. scutellata from the western humid midlands, A. m. bandasii from sub-moist central highlands and A. m. monticola from the northern mountainous parts of the study areas. These different geographical races were found to be distinctively distributed in the different ecological parts of the study area. High intercolonial and intracolonial variances were observed in all localities, however particularly high values were obtained in areas of transitions between ecological zones indicating a region of gene flow or zones of hybridisation among the statistically defined populations. Such high variances were observed mostly in areas where A. m. jemenitica borders the other geographical races. Moreover. distinct behavioural variations were also noted among these geographical races. Generally. the highland and mountainous honeybees A. m. bandasii and A. m. monticola are relatively larger in body size. have less tendency to swarm. less inclination to migrate and are relatively gentle while the converse traits were noted for the lowlands and midlands honeybees A. m. jemenitica and A. m. scutellata. Both morphological and behavioural variations were highly correlated with environmental factors and the variations seem to be the result of long adaptation to the interrelated ecological factors in their respective areas. Variations in reproductive swarming periods were also noted among these honeybee populations as a result of variations in rainfall pattern. altitude and temperature in their respective ecological areas which are believed to alter the honeybee colonies' seasonal cycles and leads to partial temporal reproductive isolation among these different honeybee populations.
- Full Text:
- Date Issued: 2003
Geography : the state of the discipline in South Africa (2000 - 2001)
- Fairhurst, U J, Davies, R J, Fox, Roddy C, Goldschagg, P, Ramutsindela, M, Bob, U, Khosa, M M
- Authors: Fairhurst, U J , Davies, R J , Fox, Roddy C , Goldschagg, P , Ramutsindela, M , Bob, U , Khosa, M M
- Date: 2003
- Language: English
- Type: Article
- Identifier: vital:6678 , http://hdl.handle.net/10962/d1006659
- Description: The research team presents the findings of a comprehensive investigation into the status and role of Geography as an academic discipline in South Africa. The paper begins by placing the discipline in historical and epistemological context. Extensive and intensive interviews were conducted with geographers at all South African universities and, on a smaller scale, in the workplace. Information was also gleaned from an array of documents. Comments on the characteristics of university departments, general school education, the geography research environment the geographer in the workplace are given. Emerging trends, many of which relate to recent socio-political change, show that contemporary emphasis is on applied geography, specific fields of specialisation, the accommodation of Environmental Science and Environmental Management, skills training and on curriculum development with a marked vocational orientation. As geographers continue addressing national and international environmental and social issues in their professional endeavours, they are alerted to critical concerns voiced with conviction by practising geographers. In the final analysis a positive conclusion is reached and the academic merit and status of the discipline is confirmed.
- Full Text:
- Date Issued: 2003
- Authors: Fairhurst, U J , Davies, R J , Fox, Roddy C , Goldschagg, P , Ramutsindela, M , Bob, U , Khosa, M M
- Date: 2003
- Language: English
- Type: Article
- Identifier: vital:6678 , http://hdl.handle.net/10962/d1006659
- Description: The research team presents the findings of a comprehensive investigation into the status and role of Geography as an academic discipline in South Africa. The paper begins by placing the discipline in historical and epistemological context. Extensive and intensive interviews were conducted with geographers at all South African universities and, on a smaller scale, in the workplace. Information was also gleaned from an array of documents. Comments on the characteristics of university departments, general school education, the geography research environment the geographer in the workplace are given. Emerging trends, many of which relate to recent socio-political change, show that contemporary emphasis is on applied geography, specific fields of specialisation, the accommodation of Environmental Science and Environmental Management, skills training and on curriculum development with a marked vocational orientation. As geographers continue addressing national and international environmental and social issues in their professional endeavours, they are alerted to critical concerns voiced with conviction by practising geographers. In the final analysis a positive conclusion is reached and the academic merit and status of the discipline is confirmed.
- Full Text:
- Date Issued: 2003
Glasbury man made Clyro bells
- Authors: Lewis, Colin A
- Date: 2003
- Language: English
- Type: Article
- Identifier: vital:6182 , http://hdl.handle.net/10962/d1012377
- Description: [From Introduction] There must have been great excitement in Clyro in 1708. The existing four bells in St Michael's Church were recast by Henry Williams, the bell founder from Glasbury, into a ring of five bells. The work was apparently paid for by the owners of two of the great houses in the parish: Cabalva and Lloyney. Little is known of the four bells that existed in Clyro before Williams began his work, although they appear to have been larger than the five bells cast from their metal. The four bells swung side by side in a wooden frame in the tower of the church. This frame was altered in 1708 to accommodate bells of smaller dimensions and a fifth bell pit was added at right angles to the others. , Colin Lewis was Professor of Geography at Rhodes University, Grahamstown, South Africa from 1989 until his retirement at the end of 2007. In 1990, with the strong support of the incumbent Vice-Chancellor, Dr Derek Henderson, he instigated the Certificate in Change Ringing (Church Bell Ringing) in the Rhodes University Department of Music and Musicology - the first such course to be offered in Africa. Since that date he has lectured in the basic theory, and taught the practice of change ringing. He is the Ringing Master of the Cathedral of St Michael and St George, Grahamstown, South Africa.
- Full Text:
- Date Issued: 2003
- Authors: Lewis, Colin A
- Date: 2003
- Language: English
- Type: Article
- Identifier: vital:6182 , http://hdl.handle.net/10962/d1012377
- Description: [From Introduction] There must have been great excitement in Clyro in 1708. The existing four bells in St Michael's Church were recast by Henry Williams, the bell founder from Glasbury, into a ring of five bells. The work was apparently paid for by the owners of two of the great houses in the parish: Cabalva and Lloyney. Little is known of the four bells that existed in Clyro before Williams began his work, although they appear to have been larger than the five bells cast from their metal. The four bells swung side by side in a wooden frame in the tower of the church. This frame was altered in 1708 to accommodate bells of smaller dimensions and a fifth bell pit was added at right angles to the others. , Colin Lewis was Professor of Geography at Rhodes University, Grahamstown, South Africa from 1989 until his retirement at the end of 2007. In 1990, with the strong support of the incumbent Vice-Chancellor, Dr Derek Henderson, he instigated the Certificate in Change Ringing (Church Bell Ringing) in the Rhodes University Department of Music and Musicology - the first such course to be offered in Africa. Since that date he has lectured in the basic theory, and taught the practice of change ringing. He is the Ringing Master of the Cathedral of St Michael and St George, Grahamstown, South Africa.
- Full Text:
- Date Issued: 2003
Grade six and seven learners' perceptions of the HIV/AIDS life skills education programme
- Authors: Julies, Zainuneesa
- Date: 2003
- Subjects: AIDS (Disease) -- Study and teaching (Primary) -- South Africa -- Evaluation , AIDS (Disease) -- South Africa -- Prevention
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:10988 , http://hdl.handle.net/10948/315 , AIDS (Disease) -- Study and teaching (Primary) -- South Africa -- Evaluation , AIDS (Disease) -- South Africa -- Prevention
- Description: At present there is no cure or vaccine for Human Immuno-deficiency Virus (HIV) or Acquired Immune Deficiency Syndrome (AIDS) therefore prevention programmes are seen as the only means of reducing the spread of the disease. HIV/AIDS education programmes in schools have been identified as the most effective intervention because billions of children can be reached worldwide and because schools are the one social institution with which most children come into contact. Young people in particular have been identified as the age group most in need of a preventative programme. The aim of this study is to explore the perceptions of grade six and seven learners with regard to the Life Skills programme focusing on HIV/AIDS education in the Port Elizabeth region. In order to fulfill the above aim a qualitative study was undertaken within an exploratory descriptive approach. A non-probability, convenient sample of six schools were selected. Focus groups, utilising an unstructured interview, were used to gather qualitative data about the perceptions of grade six and seven learners. The focus groups consisted of 10-12 participants. The data was thematically analysed using Tesch’s approach. The major findings of the present study included the following: 1. Learners’ perceptions of completing the questionnaire were generally positive in nature. Negative perceptions related to practical issues such as the length of the questionnaire and the time of administration. 2. Learner’s perceptions of the programme were generally positive. 3. Learners’ felt more comfortable discussing HIV/AIDS with parents and teachers. xi 4. Learners’ appeared to be well informed about high-risk behaviour related to HIV/AIDS and existing myths. 5. Contact with HIV+ people is non-existent. However, learner’s felt that the programme had fostered positive attitudes towards HIV+ people. 6. Learner’s felt that schools had an important role to play in sharing information about HIV/AIDS. These findings seem to indicate positive outcomes for the programme as a whole, in that is was successful in terms of conveying information regarding HIV/AIDS; it led to positive changes in attitudes, especially towards HIV+ people; and it confirmed the school as the best setting for implementing HIV/AIDS Life Skills programmes.
- Full Text:
- Date Issued: 2003
- Authors: Julies, Zainuneesa
- Date: 2003
- Subjects: AIDS (Disease) -- Study and teaching (Primary) -- South Africa -- Evaluation , AIDS (Disease) -- South Africa -- Prevention
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:10988 , http://hdl.handle.net/10948/315 , AIDS (Disease) -- Study and teaching (Primary) -- South Africa -- Evaluation , AIDS (Disease) -- South Africa -- Prevention
- Description: At present there is no cure or vaccine for Human Immuno-deficiency Virus (HIV) or Acquired Immune Deficiency Syndrome (AIDS) therefore prevention programmes are seen as the only means of reducing the spread of the disease. HIV/AIDS education programmes in schools have been identified as the most effective intervention because billions of children can be reached worldwide and because schools are the one social institution with which most children come into contact. Young people in particular have been identified as the age group most in need of a preventative programme. The aim of this study is to explore the perceptions of grade six and seven learners with regard to the Life Skills programme focusing on HIV/AIDS education in the Port Elizabeth region. In order to fulfill the above aim a qualitative study was undertaken within an exploratory descriptive approach. A non-probability, convenient sample of six schools were selected. Focus groups, utilising an unstructured interview, were used to gather qualitative data about the perceptions of grade six and seven learners. The focus groups consisted of 10-12 participants. The data was thematically analysed using Tesch’s approach. The major findings of the present study included the following: 1. Learners’ perceptions of completing the questionnaire were generally positive in nature. Negative perceptions related to practical issues such as the length of the questionnaire and the time of administration. 2. Learner’s perceptions of the programme were generally positive. 3. Learners’ felt more comfortable discussing HIV/AIDS with parents and teachers. xi 4. Learners’ appeared to be well informed about high-risk behaviour related to HIV/AIDS and existing myths. 5. Contact with HIV+ people is non-existent. However, learner’s felt that the programme had fostered positive attitudes towards HIV+ people. 6. Learner’s felt that schools had an important role to play in sharing information about HIV/AIDS. These findings seem to indicate positive outcomes for the programme as a whole, in that is was successful in terms of conveying information regarding HIV/AIDS; it led to positive changes in attitudes, especially towards HIV+ people; and it confirmed the school as the best setting for implementing HIV/AIDS Life Skills programmes.
- Full Text:
- Date Issued: 2003
Holding on or letting go?: the resolution of grief in relation to two Xhosa rituals in South Africa
- Authors: Van Heerden, Gary Paul
- Date: 2003
- Subjects: South Africa -- Social life and customs , Death -- Social aspects -- South Africa , Mourning customs -- South Africa , Bereavement -- Psychological aspects , Bereavement -- South Africa -- Cross-cultural studies , Death -- South Africa -- Cross-cultural studies , Xhosa (African people) -- Rites and ceremonies , Xhosa (African people) -- Social life and customs , Animal sacrifice -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3253 , http://hdl.handle.net/10962/d1016055
- Description: The dominant emphasis in Western models of bereavement is on the breaking of bonds with the deceased in order for healing to occur. Failure to let go often leads to a diagnosis of 'pathological grief'. This paper challenges the assumption that death invariably means that the bonds with the deceased have to be severed. Situating Western models of bereavement in a modernist context not only challenges the 'truth' claims of these models, but also facilitates a deconstruction of the elements that contribute to the emphasis on letting go. In contrast to these theories, two Xhosa rituals (umkhapho and umbuyiso) that seek to sustain the bond with the deceased person will be examined. Such rituals demonstrate that it is possible to both maintain the bond and for the bereaved person to move on with their lives. Despite different contexts, it will be argued that these Xhosa bereavement rituals have a contribution to make to Western models of bereavement and some implications for therapy will be explored.
- Full Text:
- Date Issued: 2003
- Authors: Van Heerden, Gary Paul
- Date: 2003
- Subjects: South Africa -- Social life and customs , Death -- Social aspects -- South Africa , Mourning customs -- South Africa , Bereavement -- Psychological aspects , Bereavement -- South Africa -- Cross-cultural studies , Death -- South Africa -- Cross-cultural studies , Xhosa (African people) -- Rites and ceremonies , Xhosa (African people) -- Social life and customs , Animal sacrifice -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3253 , http://hdl.handle.net/10962/d1016055
- Description: The dominant emphasis in Western models of bereavement is on the breaking of bonds with the deceased in order for healing to occur. Failure to let go often leads to a diagnosis of 'pathological grief'. This paper challenges the assumption that death invariably means that the bonds with the deceased have to be severed. Situating Western models of bereavement in a modernist context not only challenges the 'truth' claims of these models, but also facilitates a deconstruction of the elements that contribute to the emphasis on letting go. In contrast to these theories, two Xhosa rituals (umkhapho and umbuyiso) that seek to sustain the bond with the deceased person will be examined. Such rituals demonstrate that it is possible to both maintain the bond and for the bereaved person to move on with their lives. Despite different contexts, it will be argued that these Xhosa bereavement rituals have a contribution to make to Western models of bereavement and some implications for therapy will be explored.
- Full Text:
- Date Issued: 2003
Host-preference and density of woodrose-forming mistletoes (Loranthaceae) on savanna vegetation, South Africa
- Dzerefos, Cathy M, Witkowski, Ed T F, Shackleton, Charlie M
- Authors: Dzerefos, Cathy M , Witkowski, Ed T F , Shackleton, Charlie M
- Date: 2003
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/181487 , vital:43738 , xlink:href="https://doi.org/10.1023/A:1023991514968"
- Description: In the Bushbuckridge region of South Africa host preference and density of two woodrose-forming mistletoes, Erianthemum dregei (Eckl. and Zeyh.) V. Tieghem and Pedistylis galpinii (Schinz ex Sprague) was quantified in relation to land-use (harvested or unharvested), rainfall (high, more than 660 or low , less than 660 mm year−1) and catenal position (top or lower slope). These two mistletoes are generalist hemi-parasites of savanna trees and shrubs occurring on 25 and 17 hosts respectively, seven of which are shared. Thirty-six percent of woody plant species recorded were found to be hosts. Although Sclerocarya birrea (A. Rich.) Hochst. comprised only 4% of woody plant density in the environment, it was the principal host for both mistletoes, accounting for 71% of total E. dregei and 42% of P. galpinii infection. Mistletoe infection relative to density of Ficus stuhlmanii, Trichilia emetica and Cassine transvaalensis indicated that these were preferential hosts to S. birrea. Mistletoe host preference was negatively correlated with host wood density. Mistletoe number per tree had a weak relationship to canopy size. Mistletoes of all size classes were denser at high rainfall relative to low rainfall sites. Interestingly, the overall mistletoe size class distribution was similar between harvested and unharvested sites. The ratio of living to dead mistletoe was 2 to 1 for E. dregei and 1.5 to 1 for P. galpinii. There are sufficient dead mistletoes in unharvested and harvested areas to satisfy present market demand. Living E. dregei predominated in harvested rather than unharvested areas suggesting that current-harvesting levels had little or no negative effect on the population. In contrast, P. galpinii was denser in unharvested areas possibly owing to its higher market value and thus higher harvesting levels.
- Full Text:
- Date Issued: 2003
- Authors: Dzerefos, Cathy M , Witkowski, Ed T F , Shackleton, Charlie M
- Date: 2003
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/181487 , vital:43738 , xlink:href="https://doi.org/10.1023/A:1023991514968"
- Description: In the Bushbuckridge region of South Africa host preference and density of two woodrose-forming mistletoes, Erianthemum dregei (Eckl. and Zeyh.) V. Tieghem and Pedistylis galpinii (Schinz ex Sprague) was quantified in relation to land-use (harvested or unharvested), rainfall (high, more than 660 or low , less than 660 mm year−1) and catenal position (top or lower slope). These two mistletoes are generalist hemi-parasites of savanna trees and shrubs occurring on 25 and 17 hosts respectively, seven of which are shared. Thirty-six percent of woody plant species recorded were found to be hosts. Although Sclerocarya birrea (A. Rich.) Hochst. comprised only 4% of woody plant density in the environment, it was the principal host for both mistletoes, accounting for 71% of total E. dregei and 42% of P. galpinii infection. Mistletoe infection relative to density of Ficus stuhlmanii, Trichilia emetica and Cassine transvaalensis indicated that these were preferential hosts to S. birrea. Mistletoe host preference was negatively correlated with host wood density. Mistletoe number per tree had a weak relationship to canopy size. Mistletoes of all size classes were denser at high rainfall relative to low rainfall sites. Interestingly, the overall mistletoe size class distribution was similar between harvested and unharvested sites. The ratio of living to dead mistletoe was 2 to 1 for E. dregei and 1.5 to 1 for P. galpinii. There are sufficient dead mistletoes in unharvested and harvested areas to satisfy present market demand. Living E. dregei predominated in harvested rather than unharvested areas suggesting that current-harvesting levels had little or no negative effect on the population. In contrast, P. galpinii was denser in unharvested areas possibly owing to its higher market value and thus higher harvesting levels.
- Full Text:
- Date Issued: 2003
Hot-blooded singers: endothermy facilitates crepuscular signaling in African platypleurine cicadas (Hemiptera: Cicadidae: Platypleura spp.)
- Sanborn, Allen F, Villet, Martin H, Phillips, P K
- Authors: Sanborn, Allen F , Villet, Martin H , Phillips, P K
- Date: 2003
- Language: English
- Type: text , Article
- Identifier: vital:6919 , http://hdl.handle.net/10962/d1011882
- Description: The cicada genus Platypleura has a wide distribution across Africa and southern Asia. We describe endothermic thermoregulation in four South African species that show crepuscular signaling behavior. This is the first evidence of thermoregulation in platypleurine cicadas. Field measurements of body temperature (Tb) show that these animals regulate Tb through endogenous heat production. Maximum Tb measured was 22.1°C above ambient temperature during calling activity at dusk. The mean Tb during dusk activity did not differ from the mean Tb during diurnal activity. A unique behavior for cicadas, a temperature-dependent telescoping pulsation of the abdomen, was observed in the laboratory during endogenous warm-up. This behavior is part of a unique method of heat generation in endothermic cicadas. Males generally call from trunks and branches within the canopy and appear to use endothermy even when the sun is available to elevate Tb. Endothermy may provide the cicadas with the advantage of decreasing predation and acoustic competition by permitting calling from perches that most complement their cryptic coloration patterns and that ectotherms cannot use due to thermal constraints. In addition, endothermy may permit calling activity during crepuscular hours when atmospheric conditions are optimal for acoustic communication and predation risks are minimal.
- Full Text:
- Date Issued: 2003
- Authors: Sanborn, Allen F , Villet, Martin H , Phillips, P K
- Date: 2003
- Language: English
- Type: text , Article
- Identifier: vital:6919 , http://hdl.handle.net/10962/d1011882
- Description: The cicada genus Platypleura has a wide distribution across Africa and southern Asia. We describe endothermic thermoregulation in four South African species that show crepuscular signaling behavior. This is the first evidence of thermoregulation in platypleurine cicadas. Field measurements of body temperature (Tb) show that these animals regulate Tb through endogenous heat production. Maximum Tb measured was 22.1°C above ambient temperature during calling activity at dusk. The mean Tb during dusk activity did not differ from the mean Tb during diurnal activity. A unique behavior for cicadas, a temperature-dependent telescoping pulsation of the abdomen, was observed in the laboratory during endogenous warm-up. This behavior is part of a unique method of heat generation in endothermic cicadas. Males generally call from trunks and branches within the canopy and appear to use endothermy even when the sun is available to elevate Tb. Endothermy may provide the cicadas with the advantage of decreasing predation and acoustic competition by permitting calling from perches that most complement their cryptic coloration patterns and that ectotherms cannot use due to thermal constraints. In addition, endothermy may permit calling activity during crepuscular hours when atmospheric conditions are optimal for acoustic communication and predation risks are minimal.
- Full Text:
- Date Issued: 2003
Hybrid field generator controller for optimised perfomance
- Authors: Moleli, Christopher Teboho
- Date: 2003
- Subjects: Hybrid power systems , Wind turbines , Electric power production
- Language: English
- Type: Thesis , Masters , MTech (Electrical Engineering)
- Identifier: vital:10818 , http://hdl.handle.net/10948/236 , Hybrid power systems , Wind turbines , Electric power production
- Description: Battery charging wind turbines like, Hybrid Field Generator, have become more popular in the growing renewable energy market. With wind energy, voltage and current control is generally provided by means of power electronics. The paper describes the analytical investigation in to control aspects of a hybrid field generator controller for optimized performance. The project objective is about maintaining the generated voltage at 28V through out a generator speed range, between 149 rpm and 598 rpm. The over voltage load, known as dump load, is connected to the control circuit to reduce stress on the bypass transistor for speeds above 598 rpm. Maintaining a stable voltage through out the speed range, between 149rpm and 598rpm, is achieved by employing power electronics techniques. This is done by using power converters and inverters to vary the generator armature excitation levels hence varying its air gap flux density. All these take place during each of the three modes of generator operation, which are: buck, boost and permanent magnet modes. Although the generator controller is power electronics based, it also uses software to optimize its performance. In this case, a PIC16F877 microcontroller development system has been used to test the controller function blocks.
- Full Text:
- Date Issued: 2003
- Authors: Moleli, Christopher Teboho
- Date: 2003
- Subjects: Hybrid power systems , Wind turbines , Electric power production
- Language: English
- Type: Thesis , Masters , MTech (Electrical Engineering)
- Identifier: vital:10818 , http://hdl.handle.net/10948/236 , Hybrid power systems , Wind turbines , Electric power production
- Description: Battery charging wind turbines like, Hybrid Field Generator, have become more popular in the growing renewable energy market. With wind energy, voltage and current control is generally provided by means of power electronics. The paper describes the analytical investigation in to control aspects of a hybrid field generator controller for optimized performance. The project objective is about maintaining the generated voltage at 28V through out a generator speed range, between 149 rpm and 598 rpm. The over voltage load, known as dump load, is connected to the control circuit to reduce stress on the bypass transistor for speeds above 598 rpm. Maintaining a stable voltage through out the speed range, between 149rpm and 598rpm, is achieved by employing power electronics techniques. This is done by using power converters and inverters to vary the generator armature excitation levels hence varying its air gap flux density. All these take place during each of the three modes of generator operation, which are: buck, boost and permanent magnet modes. Although the generator controller is power electronics based, it also uses software to optimize its performance. In this case, a PIC16F877 microcontroller development system has been used to test the controller function blocks.
- Full Text:
- Date Issued: 2003
Implementing Location Services in the Location-Transparent, Distributed Environment of the Internet
- Clayton, Peter G, Preston, Michael, Wells, George C
- Authors: Clayton, Peter G , Preston, Michael , Wells, George C
- Date: 2003
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/430467 , vital:72693 , https://link.springer.com/book/10.1007/b13582?page=1#toc
- Description: This volume contains the papers presented at the 5th International Workshop on Advanced Parallel Processing Technologies, APPT 2003. This series of workshops is designed to strengthen the cooperation between the German and Chinese institutions active in the area of these technologies. It has continued to grow, providing an excellent forum for reporting advances in parallel processing technologies. The 5th workshop itself addressed the entire gamut of related topics, ranging from the architectural aspects of parallel computer hardware and system software to the applied technologies for novel applica-tions. For this workshop, we received over 191 full submissions from researchers all over the world. All the papers were peer-reviewed in depth and qualitatively graded on their relevance, originality, signi?cance, presentation, and the overall appropriateness for their acceptance. Any concerns raised were discussed in the program com-mittee. The organizing committee did an excellent job in selecting 78 papers (Among them, 21 were short ones) for presentation. In short, the papers included here represent the forefront of research from China, Germany, and the other countries.
- Full Text:
- Date Issued: 2003
- Authors: Clayton, Peter G , Preston, Michael , Wells, George C
- Date: 2003
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/430467 , vital:72693 , https://link.springer.com/book/10.1007/b13582?page=1#toc
- Description: This volume contains the papers presented at the 5th International Workshop on Advanced Parallel Processing Technologies, APPT 2003. This series of workshops is designed to strengthen the cooperation between the German and Chinese institutions active in the area of these technologies. It has continued to grow, providing an excellent forum for reporting advances in parallel processing technologies. The 5th workshop itself addressed the entire gamut of related topics, ranging from the architectural aspects of parallel computer hardware and system software to the applied technologies for novel applica-tions. For this workshop, we received over 191 full submissions from researchers all over the world. All the papers were peer-reviewed in depth and qualitatively graded on their relevance, originality, signi?cance, presentation, and the overall appropriateness for their acceptance. Any concerns raised were discussed in the program com-mittee. The organizing committee did an excellent job in selecting 78 papers (Among them, 21 were short ones) for presentation. In short, the papers included here represent the forefront of research from China, Germany, and the other countries.
- Full Text:
- Date Issued: 2003
Implications of a new 40Ar/ 39Ar age for a basalt flow interbedded with the Etjo Formation, Northeast Namibia
- Marsh, Julian S, Swart, Roger S, Phillips, D
- Authors: Marsh, Julian S , Swart, Roger S , Phillips, D
- Date: 2003
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/150364 , vital:38970 , https://doi.org/10.2113/106.4.281
- Description: A reliable 40Ar/39Ar plateau age of 180 ± 1.2 Ma (1σ) has been obtained for fresh basalt lava interbedded with aeolian Etjo Formation sandstones south-southwest of Grootfontein in northeast Namibia. This indicates that the Early Jurassic Karoo flood basalt sequence extended from Botswana into northeast Namibia at least as far as 18 east and that this may mark the eastern extent of the Early Cretaceous Etendeka Igneous Province.
- Full Text: false
- Date Issued: 2003
- Authors: Marsh, Julian S , Swart, Roger S , Phillips, D
- Date: 2003
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/150364 , vital:38970 , https://doi.org/10.2113/106.4.281
- Description: A reliable 40Ar/39Ar plateau age of 180 ± 1.2 Ma (1σ) has been obtained for fresh basalt lava interbedded with aeolian Etjo Formation sandstones south-southwest of Grootfontein in northeast Namibia. This indicates that the Early Jurassic Karoo flood basalt sequence extended from Botswana into northeast Namibia at least as far as 18 east and that this may mark the eastern extent of the Early Cretaceous Etendeka Igneous Province.
- Full Text: false
- Date Issued: 2003
In defence of moral objectivity
- Authors: McKaiser, Eusebius
- Date: 2003 , 2013-05-23
- Subjects: Ethics , Objectivity
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2740 , http://hdl.handle.net/10962/d1007599 , Ethics , Objectivity
- Description: This thesis examines the problem of moral objectivity, which is constituted by the ontological, epistemological and motivational challenges. It gradually develops an account of moral objectivity that has the dual function of dealing with the enemies of moral objectivity as well as giving a positive account of what moral objectivity is. It establishes these aims by arguing for the following theses. The first set of arguments show that relativist theories of ethics provide us with no forceful grounds for being sceptical about moral objectivity. The second set of arguments deepens the response to those who are sceptical about moral objectivity. It does so by showing in greater detail how rationality plays a substantive role in our practical deliberation, our notion of agency as well as our reactive attitudes. These arguments provide further reasons why we should have faith in the possibility of developing an adequate account of moral objectivity. The last set of arguments provides the positive account of moral objectivity. This positive account ends with the discussion of a paradigmatic moral fact that gives full expression (to the features of moral objectivity that have been articulated and defended.
- Full Text:
- Date Issued: 2003
- Authors: McKaiser, Eusebius
- Date: 2003 , 2013-05-23
- Subjects: Ethics , Objectivity
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2740 , http://hdl.handle.net/10962/d1007599 , Ethics , Objectivity
- Description: This thesis examines the problem of moral objectivity, which is constituted by the ontological, epistemological and motivational challenges. It gradually develops an account of moral objectivity that has the dual function of dealing with the enemies of moral objectivity as well as giving a positive account of what moral objectivity is. It establishes these aims by arguing for the following theses. The first set of arguments show that relativist theories of ethics provide us with no forceful grounds for being sceptical about moral objectivity. The second set of arguments deepens the response to those who are sceptical about moral objectivity. It does so by showing in greater detail how rationality plays a substantive role in our practical deliberation, our notion of agency as well as our reactive attitudes. These arguments provide further reasons why we should have faith in the possibility of developing an adequate account of moral objectivity. The last set of arguments provides the positive account of moral objectivity. This positive account ends with the discussion of a paradigmatic moral fact that gives full expression (to the features of moral objectivity that have been articulated and defended.
- Full Text:
- Date Issued: 2003
Indomethacin reduces lipid peroxidation in rat brain homogenate by binding Fe2+
- Anoopkumar-Dukie, Shailendra, Lack, Barbara, McPhail, Kerry L, Nyokong, Tebello, Lambat, Zaynab, Maharaj, Deepat, Daya, Santy
- Authors: Anoopkumar-Dukie, Shailendra , Lack, Barbara , McPhail, Kerry L , Nyokong, Tebello , Lambat, Zaynab , Maharaj, Deepat , Daya, Santy
- Date: 2003
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/304763 , vital:58487 , xlink:href="https://doi.org/10.1023/A:1021958016928"
- Description: One of the hallmarks of Alzheimer's disease (AD) is the progressive degeneration of cholinergic neurons in the cerebral cortex and hippocampus. It is generally accepted that this neuronal degeneration is due to free-radical-induced damage. These free radicals attack vital structural components of the neurons. This implies that agents that reduce free radical generation could potentially delay the progression of AD. Free radical generation in the brain is assisted by the presence of iron, required by the Fenton reaction. Thus, agents that reduce iron availability for this reaction could potentially reduce free radical formation. Since non steroidal anti-inflammatory drugs (NSAIDS) have been shown to reduce the severity of AD, we investigated the possible mechanism by which indomethacin could afford neuroprotection. Our results show that indomethacin (1 mM) is able to reduce the iron-induced rise in lipid peroxidation in rat brain homogenates. In addition, our NMR data indicate that indomethacin binds the Fe2+/Fe3+ ion. This was confirmed by a study using UV/Vis spectrophotometry. The results imply that indomethacin provides a neuroprotective effect by binding to iron and thus making it unavailable for free radical production.
- Full Text:
- Date Issued: 2003
- Authors: Anoopkumar-Dukie, Shailendra , Lack, Barbara , McPhail, Kerry L , Nyokong, Tebello , Lambat, Zaynab , Maharaj, Deepat , Daya, Santy
- Date: 2003
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/304763 , vital:58487 , xlink:href="https://doi.org/10.1023/A:1021958016928"
- Description: One of the hallmarks of Alzheimer's disease (AD) is the progressive degeneration of cholinergic neurons in the cerebral cortex and hippocampus. It is generally accepted that this neuronal degeneration is due to free-radical-induced damage. These free radicals attack vital structural components of the neurons. This implies that agents that reduce free radical generation could potentially delay the progression of AD. Free radical generation in the brain is assisted by the presence of iron, required by the Fenton reaction. Thus, agents that reduce iron availability for this reaction could potentially reduce free radical formation. Since non steroidal anti-inflammatory drugs (NSAIDS) have been shown to reduce the severity of AD, we investigated the possible mechanism by which indomethacin could afford neuroprotection. Our results show that indomethacin (1 mM) is able to reduce the iron-induced rise in lipid peroxidation in rat brain homogenates. In addition, our NMR data indicate that indomethacin binds the Fe2+/Fe3+ ion. This was confirmed by a study using UV/Vis spectrophotometry. The results imply that indomethacin provides a neuroprotective effect by binding to iron and thus making it unavailable for free radical production.
- Full Text:
- Date Issued: 2003