Lessons for South Africa's national identity: the political writings of Aggrey Klaaste
- Authors: Sowaga, Dulile Frans
- Date: 2012
- Subjects: South Africa -- Politics and government , Democracy -- South Africa , Multiculturalism -- South Africa , Nationalism -- South Africa
- Language: English
- Type: Thesis , Masters , MPhil
- Identifier: vital:8359 , http://hdl.handle.net/10948/d1021077
- Description: This study is a content analysis of political writings of Aggrey Klaaste (1988-2002). Six theoretical themes suggest that Klaaste’s Nation Building philosophy can help deal with racial and social divisions in the country. These historical divisions are the source of racial tensions, lack of inter-racial socialisations and cause separate living. Lack of social cohesion makes it impossible for post apartheid South Africa to achieve much-needed single national identity. The process of nation building proposed by Klaaste starts with breaking down what he refers to as ‘the corrugated iron curtain’. Social curtaining is deliberate actions by people of different racial groups, religious formations and social classes to build psychological, physical, institutional, political, economic and religious boundaries around themselves to keep others outside their living spaces. These conscious barriers result in unstable democracy as the majority (black population) get frustrated with shack dwellings - as symbols of poverty - while the white population and the middle class blacks move to white suburbs. Moving to upmarket suburbs does not necessarily make race groups to cohere and share a common national identity. Instead informal settlements breed social ills such as poverty, crime and drug substances abuse. This status quo can cause serious political instability which will affect everyone – black and white. Klaaste argues that for collective survival all race groups need to enter into politics of action. For this he proposes specific processes and actions through Nation Building. It is argued that political solutions have failed to unite people and leaders from all sectors of society should emerge. Blacks cannot moan and hate forever. Whites will be affected and must actively support the rebuilding process. This treatise proposes nation building as a process to help everyone to find uniting issues free of political ideologies to create new brotherhood and Ubuntu.
- Full Text:
- Date Issued: 2012
- Authors: Sowaga, Dulile Frans
- Date: 2012
- Subjects: South Africa -- Politics and government , Democracy -- South Africa , Multiculturalism -- South Africa , Nationalism -- South Africa
- Language: English
- Type: Thesis , Masters , MPhil
- Identifier: vital:8359 , http://hdl.handle.net/10948/d1021077
- Description: This study is a content analysis of political writings of Aggrey Klaaste (1988-2002). Six theoretical themes suggest that Klaaste’s Nation Building philosophy can help deal with racial and social divisions in the country. These historical divisions are the source of racial tensions, lack of inter-racial socialisations and cause separate living. Lack of social cohesion makes it impossible for post apartheid South Africa to achieve much-needed single national identity. The process of nation building proposed by Klaaste starts with breaking down what he refers to as ‘the corrugated iron curtain’. Social curtaining is deliberate actions by people of different racial groups, religious formations and social classes to build psychological, physical, institutional, political, economic and religious boundaries around themselves to keep others outside their living spaces. These conscious barriers result in unstable democracy as the majority (black population) get frustrated with shack dwellings - as symbols of poverty - while the white population and the middle class blacks move to white suburbs. Moving to upmarket suburbs does not necessarily make race groups to cohere and share a common national identity. Instead informal settlements breed social ills such as poverty, crime and drug substances abuse. This status quo can cause serious political instability which will affect everyone – black and white. Klaaste argues that for collective survival all race groups need to enter into politics of action. For this he proposes specific processes and actions through Nation Building. It is argued that political solutions have failed to unite people and leaders from all sectors of society should emerge. Blacks cannot moan and hate forever. Whites will be affected and must actively support the rebuilding process. This treatise proposes nation building as a process to help everyone to find uniting issues free of political ideologies to create new brotherhood and Ubuntu.
- Full Text:
- Date Issued: 2012
Lessons for South African identity : the political writings of Aggrey Klaaste
- Authors: Sowaga, Dulile Frans
- Date: 2012
- Subjects: Klaaste, Aggrey , National characteristics , South Africa -- Politics and government
- Language: English
- Type: Thesis , Masters , MPhil
- Identifier: vital:8306 , http://hdl.handle.net/10948/d1019997
- Description: This study is a content analysis of political writings of Aggrey Klaaste (1988-2002). Six theoretical themes suggest that Klaaste’s Nation Building philosophy can help deal with racial and social divisions in the country. These historical divisions are the source of racial tensions, lack of inter-racial socialisations and cause separate living. Lack of social cohesion makes it impossible for post apartheid South Africa to achieve much-needed single national identity. The process of nation building proposed by Klaaste starts with breaking down what he refers to as ‘the corrugated iron curtain’. Social curtaining is deliberate actions by people of different racial groups, religious formations and social classes to build psychological, physical, institutional, political, economic and religious boundaries around themselves to keep others outside their living spaces. These conscious barriers result in unstable democracy as the majority (black population) get frustrated with shack dwellings - as symbols of poverty - while the white population and the middle class blacks move to white suburbs. Moving to upmarket suburbs does not necessarily make race groups to cohere and share a common national identity. Instead informal settlements breed social ills such as poverty, crime and drug substances abuse. This status quo can cause serious political instability which will affect everyone – black and white. Klaaste argues that for collective survival all race groups need to enter into politics of action. For this he proposes specific processes and actions through Nation Building. It is argued that political solutions have failed to unite people and leaders from all sectors of society should emerge. Blacks cannot moan and hate forever. Whites will be affected and must actively support the rebuilding process. This treatise proposes nation building as a process to help everyone to find uniting issues free of political ideologies to create new brotherhood and ubuntu.
- Full Text:
- Date Issued: 2012
- Authors: Sowaga, Dulile Frans
- Date: 2012
- Subjects: Klaaste, Aggrey , National characteristics , South Africa -- Politics and government
- Language: English
- Type: Thesis , Masters , MPhil
- Identifier: vital:8306 , http://hdl.handle.net/10948/d1019997
- Description: This study is a content analysis of political writings of Aggrey Klaaste (1988-2002). Six theoretical themes suggest that Klaaste’s Nation Building philosophy can help deal with racial and social divisions in the country. These historical divisions are the source of racial tensions, lack of inter-racial socialisations and cause separate living. Lack of social cohesion makes it impossible for post apartheid South Africa to achieve much-needed single national identity. The process of nation building proposed by Klaaste starts with breaking down what he refers to as ‘the corrugated iron curtain’. Social curtaining is deliberate actions by people of different racial groups, religious formations and social classes to build psychological, physical, institutional, political, economic and religious boundaries around themselves to keep others outside their living spaces. These conscious barriers result in unstable democracy as the majority (black population) get frustrated with shack dwellings - as symbols of poverty - while the white population and the middle class blacks move to white suburbs. Moving to upmarket suburbs does not necessarily make race groups to cohere and share a common national identity. Instead informal settlements breed social ills such as poverty, crime and drug substances abuse. This status quo can cause serious political instability which will affect everyone – black and white. Klaaste argues that for collective survival all race groups need to enter into politics of action. For this he proposes specific processes and actions through Nation Building. It is argued that political solutions have failed to unite people and leaders from all sectors of society should emerge. Blacks cannot moan and hate forever. Whites will be affected and must actively support the rebuilding process. This treatise proposes nation building as a process to help everyone to find uniting issues free of political ideologies to create new brotherhood and ubuntu.
- Full Text:
- Date Issued: 2012
Life history strategy and population characteristics of an unexploited riverine cyprinid, Labeo capensis, in the largest impoundment in the Orange River Basin
- Winker, A Henning, Weyl, Olaf L F, Booth, Anthony J, Ellender, Bruce R
- Authors: Winker, A Henning , Weyl, Olaf L F , Booth, Anthony J , Ellender, Bruce R
- Date: 2012
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/124910 , vital:35709 , https://doi.10.3377/004.047.0124
- Description: Common carp (Cyprinus carpio) is one of the world’s most widely introduced and established freshwater fishes (Casal 2006). The species is considered to be one of the eight most invasive freshwater fishes (Lowe et al. 2000) and worldwide, it accounts for most of the records of successful establishments and adverse ecological effects (Casal 2006; Kulhanek et al. 2011). This invasive success suggests that feral C. carpio is equipped with a set of adaptable life history attributes that allow it to successfully colonise a wide range of habitats (Koehn 2004; Zambrano et al. 2006; Britton et al. 2007). Where feral C. carpio occurs in high densities, it is often perceived as an invasive pest species (Sivakumaran et al. 2003; Brown and Walker 2004; Koehn 2004) because it can have severe impacts on habitat heterogeneity and biodiversity by increasing water turbidity through its bottom feeding behaviour, increasing nutrient availability, decreasing benthic and macrophyte density and diversity, altering zooplankton assemblages and decreasing endemic fish abundance (Zambrano et al. 2001; Khan 2003; Kulhanek et al. 2011). Within south-east Australia, for example, C. carpio comprises the largest proportion of the ichthyobiomass in the continent’s largest river system – the Murray–Darling Basin (Gehrke et al. 1995). As a consequence, serious concerns about its threat to endemic freshwater species (Koehn 2004) have prompted several of the most recent investigations into its life history (e.g. Sivakumaran et al. 2003; Smith and Walker 2004; Brown et al. 2005). Other potential threats posed also include competition with indigenous species and the spread of diseases and parasites (Dudgeon et al. 2006). In South Africa, for example, Asian tapeworm Bothriocephalus acheilognathi is now widely distributed in seven river systems and has infected eight novel cyprinid hosts due to the translocation of infected by C. carpio from a centralized aquaculture facility (Stadtlander et al. 2011).
- Full Text:
- Date Issued: 2012
- Authors: Winker, A Henning , Weyl, Olaf L F , Booth, Anthony J , Ellender, Bruce R
- Date: 2012
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/124910 , vital:35709 , https://doi.10.3377/004.047.0124
- Description: Common carp (Cyprinus carpio) is one of the world’s most widely introduced and established freshwater fishes (Casal 2006). The species is considered to be one of the eight most invasive freshwater fishes (Lowe et al. 2000) and worldwide, it accounts for most of the records of successful establishments and adverse ecological effects (Casal 2006; Kulhanek et al. 2011). This invasive success suggests that feral C. carpio is equipped with a set of adaptable life history attributes that allow it to successfully colonise a wide range of habitats (Koehn 2004; Zambrano et al. 2006; Britton et al. 2007). Where feral C. carpio occurs in high densities, it is often perceived as an invasive pest species (Sivakumaran et al. 2003; Brown and Walker 2004; Koehn 2004) because it can have severe impacts on habitat heterogeneity and biodiversity by increasing water turbidity through its bottom feeding behaviour, increasing nutrient availability, decreasing benthic and macrophyte density and diversity, altering zooplankton assemblages and decreasing endemic fish abundance (Zambrano et al. 2001; Khan 2003; Kulhanek et al. 2011). Within south-east Australia, for example, C. carpio comprises the largest proportion of the ichthyobiomass in the continent’s largest river system – the Murray–Darling Basin (Gehrke et al. 1995). As a consequence, serious concerns about its threat to endemic freshwater species (Koehn 2004) have prompted several of the most recent investigations into its life history (e.g. Sivakumaran et al. 2003; Smith and Walker 2004; Brown et al. 2005). Other potential threats posed also include competition with indigenous species and the spread of diseases and parasites (Dudgeon et al. 2006). In South Africa, for example, Asian tapeworm Bothriocephalus acheilognathi is now widely distributed in seven river systems and has infected eight novel cyprinid hosts due to the translocation of infected by C. carpio from a centralized aquaculture facility (Stadtlander et al. 2011).
- Full Text:
- Date Issued: 2012
Life-history and stock assessment of Clarias Gariepinus in the Okavango Delta, Botswana
- Authors: Bokhutlo, Thethela
- Date: 2012
- Subjects: Catfishes -- Botswana -- Okavango River Delta , Clarias gariepinus , Aquaculture -- Botswana -- Okavango River Delta
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5297 , http://hdl.handle.net/10962/d1005142 , Catfishes -- Botswana -- Okavango River Delta , Clarias gariepinus , Aquaculture -- Botswana -- Okavango River Delta
- Description: Large catfishes (Clarias gariepinus & Clarias ngamensis) are not exploited commercially in the Okavango Delta, Botswana. They however constitute a large proportion of the gill net fishery catch (23 %) albeit as by-catch, coming second after cichlids (70 %). Monthly experimetal gill net sampling over 8 years showed that C. gariepinus was the most abundant species in the Okavango Delta by mass making up 37 % of the catch composition by fresh weight. Despite the relatively high abundance of C. gariepinus in the Okavango Delta, its status has never been fully assessed. For this reason, this study aimed to assess the status of C. gariepinus in the Okavango Delta with the particular goal to determine if the species could support a directed commercial gill net fishery. Investigation of the effects of the flood pulse on abundance of C. gariepinus showed that variability in water levels was the major driver of population abundance for this species. Three biological variables: (1) catch per unit effort (CPUE); (2) % catch composition and (3) Shannon's diversity index (H') exhibited a negative and significant relationship with the flood index within a year. The variation in these variables was statistically significant between months. There was a weak positive relationship between water levels and the biological variables between years suggesting increase in productivity of the system at high water levels without a lag period. Age and growth were determined using sectioned otoliths. Edge analysis showed that growth zone deposition occurred during the drawdown period in summer when water temperature and day length were increasing. The maximum recorded age was 15 years. Growth of this species was best described by the linear models (y = 21.50x + 427.39 mm LT; r² = 0.35) for females and (y = 23.79x + 440.83 mm LT; r² = 0.38) for males. The von Bertalanffy growth model described growth as Lt = 10000(1- exp(-0.002(t + 18.07))) mm LT for combined sexes Lt = 10000(1- exp( -0.002(t + 18.50))) mm LT , for females and Lt =908(1-exp(-0.076(t+7.95)))mmLT for males. Age at 50 % maturity was attained in the first year of life. Spawning occurred throughout the year with an apparent peak between November and April. The mean total annual mortality rate (Z) was 0.25 per year. The mean annual natural mortality rate (M) was 0.20 per year and fishing mortality (F) was calculated at 0.05 per year. The life history strategy of C. gariepinus was in between the periodic and opportunistic strategies. Therefore management of this species should be aimed at maintaining a healthy adult population and age structure. Since a large portion of the Okavango Delta is already protected and most other parts are also inaccessible to fishers there are enough spatial refugia for the species and the status quo should be maintained. Under this scenario, there is no need for regulation of the current mesh sizes because the species is harvested after maturity and replenishment of exploited populations will always occur from other parts of the system. Per recruit analyses indicate that the current fishing mortality maintains spawner biomass at levels greater than 90 % of pristine levels. Therefore a commercial fishery may be established using mesh 93 mm to maximize yield with a rotational harvesting strategy. Close monitoring is essential to ensure that re-colonization of overexploited habitats does indeed occur. Recreational angling and commercial gill net fishing need to be separated on a spatial and temporal scale during the feeding run to minimize potential conflicts.
- Full Text:
- Date Issued: 2012
- Authors: Bokhutlo, Thethela
- Date: 2012
- Subjects: Catfishes -- Botswana -- Okavango River Delta , Clarias gariepinus , Aquaculture -- Botswana -- Okavango River Delta
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5297 , http://hdl.handle.net/10962/d1005142 , Catfishes -- Botswana -- Okavango River Delta , Clarias gariepinus , Aquaculture -- Botswana -- Okavango River Delta
- Description: Large catfishes (Clarias gariepinus & Clarias ngamensis) are not exploited commercially in the Okavango Delta, Botswana. They however constitute a large proportion of the gill net fishery catch (23 %) albeit as by-catch, coming second after cichlids (70 %). Monthly experimetal gill net sampling over 8 years showed that C. gariepinus was the most abundant species in the Okavango Delta by mass making up 37 % of the catch composition by fresh weight. Despite the relatively high abundance of C. gariepinus in the Okavango Delta, its status has never been fully assessed. For this reason, this study aimed to assess the status of C. gariepinus in the Okavango Delta with the particular goal to determine if the species could support a directed commercial gill net fishery. Investigation of the effects of the flood pulse on abundance of C. gariepinus showed that variability in water levels was the major driver of population abundance for this species. Three biological variables: (1) catch per unit effort (CPUE); (2) % catch composition and (3) Shannon's diversity index (H') exhibited a negative and significant relationship with the flood index within a year. The variation in these variables was statistically significant between months. There was a weak positive relationship between water levels and the biological variables between years suggesting increase in productivity of the system at high water levels without a lag period. Age and growth were determined using sectioned otoliths. Edge analysis showed that growth zone deposition occurred during the drawdown period in summer when water temperature and day length were increasing. The maximum recorded age was 15 years. Growth of this species was best described by the linear models (y = 21.50x + 427.39 mm LT; r² = 0.35) for females and (y = 23.79x + 440.83 mm LT; r² = 0.38) for males. The von Bertalanffy growth model described growth as Lt = 10000(1- exp(-0.002(t + 18.07))) mm LT for combined sexes Lt = 10000(1- exp( -0.002(t + 18.50))) mm LT , for females and Lt =908(1-exp(-0.076(t+7.95)))mmLT for males. Age at 50 % maturity was attained in the first year of life. Spawning occurred throughout the year with an apparent peak between November and April. The mean total annual mortality rate (Z) was 0.25 per year. The mean annual natural mortality rate (M) was 0.20 per year and fishing mortality (F) was calculated at 0.05 per year. The life history strategy of C. gariepinus was in between the periodic and opportunistic strategies. Therefore management of this species should be aimed at maintaining a healthy adult population and age structure. Since a large portion of the Okavango Delta is already protected and most other parts are also inaccessible to fishers there are enough spatial refugia for the species and the status quo should be maintained. Under this scenario, there is no need for regulation of the current mesh sizes because the species is harvested after maturity and replenishment of exploited populations will always occur from other parts of the system. Per recruit analyses indicate that the current fishing mortality maintains spawner biomass at levels greater than 90 % of pristine levels. Therefore a commercial fishery may be established using mesh 93 mm to maximize yield with a rotational harvesting strategy. Close monitoring is essential to ensure that re-colonization of overexploited habitats does indeed occur. Recreational angling and commercial gill net fishing need to be separated on a spatial and temporal scale during the feeding run to minimize potential conflicts.
- Full Text:
- Date Issued: 2012
Life-history characteristics of an age-validated established invasive African sharptooth catfish, Clarias gariepinus, population in a warm–temperate African impoundment
- Wartenberg, Reece, Weyl, Olaf L F, Booth, Anthony J, Winker, A Henning
- Authors: Wartenberg, Reece , Weyl, Olaf L F , Booth, Anthony J , Winker, A Henning
- Date: 2012
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/124921 , vital:35710 , https://doi.10.3377/004.048.0225
- Description: African sharptooth catfish Clarias gariepinus (Burchell, 1822) is a widely distributed fish that has now invaded water bodies in South America, Eastern Europe, Asia and South Africa (Cambray 2003). In South Africa it is native as far south as the Orange-Vaal river system, but inter-basin water transfer schemes (IBWTs), illegal stocking by anglers and from aquaculture has resulted in the establishment of extralimital populations in almost all river systems (van Rensburg et al. 2011). Within the Eastern Cape Province, C. gariepinus has invaded the Great Fish and Sundays rivers through IBWTs, that connect the Orange River to the Great Fish River and then to the Sundays River system which flows directly into Darlington Dam (Kadye & Booth 2013a) (Fig. 1). Soon after the completion of the IBWTs sharptooth catfish were recorded in Grassridge Dam in 1976 (Laurenson & Hocutt 1985), and later from Darlington Dam in 1981 (Scott et al. 2006). Although Cambray & Jubb (1977) are of the opinion that the species was translocated prior to the IBWT connection, there is now a permanent corridor between the Orange River and its receiving river systems that can facilitate the continued introduction of non-native Orange River fishes and other aquatic biota.
- Full Text:
- Date Issued: 2012
- Authors: Wartenberg, Reece , Weyl, Olaf L F , Booth, Anthony J , Winker, A Henning
- Date: 2012
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/124921 , vital:35710 , https://doi.10.3377/004.048.0225
- Description: African sharptooth catfish Clarias gariepinus (Burchell, 1822) is a widely distributed fish that has now invaded water bodies in South America, Eastern Europe, Asia and South Africa (Cambray 2003). In South Africa it is native as far south as the Orange-Vaal river system, but inter-basin water transfer schemes (IBWTs), illegal stocking by anglers and from aquaculture has resulted in the establishment of extralimital populations in almost all river systems (van Rensburg et al. 2011). Within the Eastern Cape Province, C. gariepinus has invaded the Great Fish and Sundays rivers through IBWTs, that connect the Orange River to the Great Fish River and then to the Sundays River system which flows directly into Darlington Dam (Kadye & Booth 2013a) (Fig. 1). Soon after the completion of the IBWTs sharptooth catfish were recorded in Grassridge Dam in 1976 (Laurenson & Hocutt 1985), and later from Darlington Dam in 1981 (Scott et al. 2006). Although Cambray & Jubb (1977) are of the opinion that the species was translocated prior to the IBWT connection, there is now a permanent corridor between the Orange River and its receiving river systems that can facilitate the continued introduction of non-native Orange River fishes and other aquatic biota.
- Full Text:
- Date Issued: 2012
Like a bolt from the blue : phthalocyanines in biomedical optics
- Sekkat, N, Van den Berg, H, Nyokong, Tebello, Lange, N
- Authors: Sekkat, N , Van den Berg, H , Nyokong, Tebello , Lange, N
- Date: 2012
- Subjects: Biomedical optics Fluorescence diagnosis Phthalocyanines NIR dyes Photodynamic therapy
- Language: English
- Type: Article
- Identifier: vital:6597 , http://hdl.handle.net/10962/d1004346 , http://dx.doi.org/10.3390/molecules17010098
- Description: The purpose of this review is to compile preclinical and clinical results on phthalocyanines (Pcs) as photosensitizers (PS) for Photodynamic Therapy (PDT) and contrast agents for fluorescence imaging. Indeed, Pcs are excellent candidates in these fields due to their strong absorbance in the NIR region and high chemical and photo-stability. In particular, this is mostly relevant for their in vivo activation in deeper tissular regions. However, most Pcs present two major limitations, i.e., a strong tendency to aggregate and a low water-solubility. In order to overcome these issues, both chemical tuning and pharmaceutical formulation combined with tumor targeting strategies were applied. These aspects will be developed in this review for the most extensively studied Pcs during the last 25 years, i.e., aluminium-, zinc- and silicon-based Pcs.
- Full Text:
- Date Issued: 2012
- Authors: Sekkat, N , Van den Berg, H , Nyokong, Tebello , Lange, N
- Date: 2012
- Subjects: Biomedical optics Fluorescence diagnosis Phthalocyanines NIR dyes Photodynamic therapy
- Language: English
- Type: Article
- Identifier: vital:6597 , http://hdl.handle.net/10962/d1004346 , http://dx.doi.org/10.3390/molecules17010098
- Description: The purpose of this review is to compile preclinical and clinical results on phthalocyanines (Pcs) as photosensitizers (PS) for Photodynamic Therapy (PDT) and contrast agents for fluorescence imaging. Indeed, Pcs are excellent candidates in these fields due to their strong absorbance in the NIR region and high chemical and photo-stability. In particular, this is mostly relevant for their in vivo activation in deeper tissular regions. However, most Pcs present two major limitations, i.e., a strong tendency to aggregate and a low water-solubility. In order to overcome these issues, both chemical tuning and pharmaceutical formulation combined with tumor targeting strategies were applied. These aspects will be developed in this review for the most extensively studied Pcs during the last 25 years, i.e., aluminium-, zinc- and silicon-based Pcs.
- Full Text:
- Date Issued: 2012
Linking poverty, HIV/AIDS and climate change to human and ecosystem vulnerability in southern Africa: Consequences for livelihoods and sustainable ecosystem management
- Shackleton, Sheona E, Shackleton, Charlie M
- Authors: Shackleton, Sheona E , Shackleton, Charlie M
- Date: 2012
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/181081 , vital:43697 , xlink:href="https://doi.org/10.1080/13504509.2011.641039"
- Description: People in southern Africa are facing escalating levels of risk, uncertainty and consequently vulnerability as a result of multiple interacting stressors, including HIV/AIDS, poverty, food insecurity, weak governance, climate change and land degradation, to name but a few. Vulnerability or livelihood insecurity emerges when poor people as individuals or social units have to face harmful threats or shocks with inadequate capacity to respond effectively. In such situations, people often have no choice but to turn to their immediate environment for support. Evidence suggests that rising levels of human vulnerability are driving increased dependency on biodiversity and ecosystem services, which in turn, and along with other threats, is rendering ecosystems more vulnerable. This paper explores the dynamic and complex linkages and feedbacks between human vulnerability and ecosystem vulnerability, drawing on data from the southern African region. Human vulnerability is conceptualized as a threat to ecosystem health, as driven by the interplay between a number of current and emerging factors. We focus on poverty, HIV/AIDS and more intense climate extremes as examples of stressors on livelihoods and direct and indirect drivers of ecosystem change. We discuss how some of the responses to increased vulnerability may pose threats to biodiversity conservation, ecosystem management and sustainable development, whilst considering potential solutions that rely on a thorough understanding of coupled social–ecological systems and the interplay between multiple stressors and responses at different scales.
- Full Text:
- Date Issued: 2012
- Authors: Shackleton, Sheona E , Shackleton, Charlie M
- Date: 2012
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/181081 , vital:43697 , xlink:href="https://doi.org/10.1080/13504509.2011.641039"
- Description: People in southern Africa are facing escalating levels of risk, uncertainty and consequently vulnerability as a result of multiple interacting stressors, including HIV/AIDS, poverty, food insecurity, weak governance, climate change and land degradation, to name but a few. Vulnerability or livelihood insecurity emerges when poor people as individuals or social units have to face harmful threats or shocks with inadequate capacity to respond effectively. In such situations, people often have no choice but to turn to their immediate environment for support. Evidence suggests that rising levels of human vulnerability are driving increased dependency on biodiversity and ecosystem services, which in turn, and along with other threats, is rendering ecosystems more vulnerable. This paper explores the dynamic and complex linkages and feedbacks between human vulnerability and ecosystem vulnerability, drawing on data from the southern African region. Human vulnerability is conceptualized as a threat to ecosystem health, as driven by the interplay between a number of current and emerging factors. We focus on poverty, HIV/AIDS and more intense climate extremes as examples of stressors on livelihoods and direct and indirect drivers of ecosystem change. We discuss how some of the responses to increased vulnerability may pose threats to biodiversity conservation, ecosystem management and sustainable development, whilst considering potential solutions that rely on a thorough understanding of coupled social–ecological systems and the interplay between multiple stressors and responses at different scales.
- Full Text:
- Date Issued: 2012
Liquidity risk management by Zimbabwean commercial banks
- Authors: Chikoko, Laurine
- Date: 2012
- Subjects: Liquidity (Economics) , Banks and banking -- Zimbabwe
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:9027 , http://hdl.handle.net/10948/d1020344
- Description: Macroeconomic and financial market developments in Zimbabwe since 2000 have led to an increase in many banks‟ overall exposure to liquidity risk. The thesis highlights the importance of understanding and building comprehensive liquidity frameworks as defenses against liquidity stress. This study explores liquidity and liquidity risk management practices as well as the linkages and factors that affected different types of liquidity in the Zimbabwean banking sector during the Zimbabwean dollar and multiple currency eras. The research sought to present a comprehensive analysis of Zimbabwean commercial banks‟ liquidity risk management in challenging operating environments. Two periods were selected: January 2000 to December 2008 (the Zimbabwean dollar era) and March 2009 to June 2011 (the multiple currency era). Explanatory and survey research designs were used. The study applied econometric modeling using panel regression analysis to identify the major determinants of liquidity risk for 15 commercial banks in Zimbabwe. The financing gap ratio was used as the proxy for liquidity risk. The first investigation was on liquidity risk determinants in the Zimbabwean dollar era. The econometric investigations revealed that an increase in capital adequacy reduced liquidity risk and that there was a positive relationship between size and bank illiquidity. Liquidity risk was also explained by spreads. Inflation was positively related to liquidity risk and was a significant explanatory variable. Non-performing loans were not significant in explaining commercial banks‟ illiquidity, which is contrary to expectations. The second investigation was on commercial banks‟ liquidity risk determinants in the multiple currency era by using panel monthly data. The results showed that capital adequacy had a significant negative relationship with liquidity risk. The size of the bank was significant and positively related to bank illiquidity. Unlike in the Zimbabwean dollar era, spreads were negatively related to bank liquidity risk. Again, non-performing loans were a significant explanatory variable. The reserve requirements ratio and inflation also influenced bank illiquidity in the multiple currency regime. In both investigations, robustness tests for the main findings were done with an alternative dependent variable to the financing gap ratio. To complement the econometric analysis, a survey was conducted using questionnaires and interviews for the same 15 commercial banks. Empirical analysis in this research showed that during the 2000-2008 era; (i) no liquidity risk management guidelines were issued by the Reserve Bank of Zimbabwe until 2007. Banks relied on internal efforts in managing liquidity risk (ii) Liquidity was managed daily by treasury (iii) The operating environment was challenging with high inflation rates, which led to high demand for cash withdrawals by depositors (iv) Locally owned banks were more exposed to liquidity risk as compared to the foreign owned banks (v) Major sources of funds were new deposits, retention of maturities, shareholders, interbank borrowings, offshore lines of credit and also banks relied on the Reserve Bank of Zimbabwe as the lender of last resort (vi) Financial markets were active and banks offered a wide range of products (vii) To manage liquidity from depositors, banks relied on cash reserves, calculating and analysing the withdrawal patterns. When faced with cash shortages, banks relied on the daily limits set by the Reserve Bank of Zimbabwe (viii) Banks were lending but when the challenges deepened, they lent less in advances and increased investment in government securities. (ix) Inflation had major effects on liquidity risk management as it affected demand deposit tenors, fixed term products, corporate sector deposit mobilisation, cost of funds and investment portfolios (x) The regulatory environment was not favourable with RBZ policy measures designed to arrest inflation having negative repercussions on banks` liquidity management (xi) Banks had no liquidity crisis management frameworks. During the multiple currency exchange rate system (i) Commercial banks had problems in sourcing funds. They were mainly funded by transitory deposits with little coming in from treasury activities, interbank activities and offshore lines of credit. There was no lender of last resort function by the Reserve Bank of Zimbabwe. (ii) Some banks were still struggling to raise the minimum capital requirements (iii) Commercial banks offered narrow product ranges to clients (iv) To manage liquidity demand from clients, banks relied on the cash reserve ratio, and calculated the patterns of withdrawal, while some banks communicated with corporate clients on withdrawal schedules. (v) Zimbabwe commercial banks resumed the lending activity after dollarisation. Locally owned banks were aggressive, while foreign owned banks took a passive stance. There were problems with non-performing loans, especially from corporate clients, which exposed many banks to liquidity risk. (vi) Liquidity risk management in Zimbabwe was still guided by the Reserve Bank of Zimbabwe Risk Management Guideline BSD-04, 2007. All banks had liquidity risk management policies and procedure manuals but some banks were not adhering to them. Banks also had liquidity risk limits in place but some violated them. Furthermore, some banks were not conducting stress tests. Although all banks had contingency plans in place, none were testing them. Specifically, the research study highlighted the potential sources of liquidity risk in the Zimbabwean dollar and multiple currency periods. Based on the results, the study recommends survival strategies for banks in managing liquidity risk in such environments. It proposes a comprehensive liquidity management framework that clearly identifies, measures and control liquidity risk consistent with bank-specific and the country‟s macroeconomic developments. The envisaged framework would assist banks in dealing with illiquidity in a manner that would be less disruptive and that could render any future crisis less painful. Of importance is the recommendation that the central bank might not need to be too strict or too relaxed, but be moderate in ensuring an enabling regulatory environment. This would help banks to manage liquidity risk and at the same time protect depositors in any challenging operating environment. In both the studied time periods, there were transitory deposits. Generally there is need to inculcate a savings culture in Zimbabwe.
- Full Text:
- Date Issued: 2012
- Authors: Chikoko, Laurine
- Date: 2012
- Subjects: Liquidity (Economics) , Banks and banking -- Zimbabwe
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:9027 , http://hdl.handle.net/10948/d1020344
- Description: Macroeconomic and financial market developments in Zimbabwe since 2000 have led to an increase in many banks‟ overall exposure to liquidity risk. The thesis highlights the importance of understanding and building comprehensive liquidity frameworks as defenses against liquidity stress. This study explores liquidity and liquidity risk management practices as well as the linkages and factors that affected different types of liquidity in the Zimbabwean banking sector during the Zimbabwean dollar and multiple currency eras. The research sought to present a comprehensive analysis of Zimbabwean commercial banks‟ liquidity risk management in challenging operating environments. Two periods were selected: January 2000 to December 2008 (the Zimbabwean dollar era) and March 2009 to June 2011 (the multiple currency era). Explanatory and survey research designs were used. The study applied econometric modeling using panel regression analysis to identify the major determinants of liquidity risk for 15 commercial banks in Zimbabwe. The financing gap ratio was used as the proxy for liquidity risk. The first investigation was on liquidity risk determinants in the Zimbabwean dollar era. The econometric investigations revealed that an increase in capital adequacy reduced liquidity risk and that there was a positive relationship between size and bank illiquidity. Liquidity risk was also explained by spreads. Inflation was positively related to liquidity risk and was a significant explanatory variable. Non-performing loans were not significant in explaining commercial banks‟ illiquidity, which is contrary to expectations. The second investigation was on commercial banks‟ liquidity risk determinants in the multiple currency era by using panel monthly data. The results showed that capital adequacy had a significant negative relationship with liquidity risk. The size of the bank was significant and positively related to bank illiquidity. Unlike in the Zimbabwean dollar era, spreads were negatively related to bank liquidity risk. Again, non-performing loans were a significant explanatory variable. The reserve requirements ratio and inflation also influenced bank illiquidity in the multiple currency regime. In both investigations, robustness tests for the main findings were done with an alternative dependent variable to the financing gap ratio. To complement the econometric analysis, a survey was conducted using questionnaires and interviews for the same 15 commercial banks. Empirical analysis in this research showed that during the 2000-2008 era; (i) no liquidity risk management guidelines were issued by the Reserve Bank of Zimbabwe until 2007. Banks relied on internal efforts in managing liquidity risk (ii) Liquidity was managed daily by treasury (iii) The operating environment was challenging with high inflation rates, which led to high demand for cash withdrawals by depositors (iv) Locally owned banks were more exposed to liquidity risk as compared to the foreign owned banks (v) Major sources of funds were new deposits, retention of maturities, shareholders, interbank borrowings, offshore lines of credit and also banks relied on the Reserve Bank of Zimbabwe as the lender of last resort (vi) Financial markets were active and banks offered a wide range of products (vii) To manage liquidity from depositors, banks relied on cash reserves, calculating and analysing the withdrawal patterns. When faced with cash shortages, banks relied on the daily limits set by the Reserve Bank of Zimbabwe (viii) Banks were lending but when the challenges deepened, they lent less in advances and increased investment in government securities. (ix) Inflation had major effects on liquidity risk management as it affected demand deposit tenors, fixed term products, corporate sector deposit mobilisation, cost of funds and investment portfolios (x) The regulatory environment was not favourable with RBZ policy measures designed to arrest inflation having negative repercussions on banks` liquidity management (xi) Banks had no liquidity crisis management frameworks. During the multiple currency exchange rate system (i) Commercial banks had problems in sourcing funds. They were mainly funded by transitory deposits with little coming in from treasury activities, interbank activities and offshore lines of credit. There was no lender of last resort function by the Reserve Bank of Zimbabwe. (ii) Some banks were still struggling to raise the minimum capital requirements (iii) Commercial banks offered narrow product ranges to clients (iv) To manage liquidity demand from clients, banks relied on the cash reserve ratio, and calculated the patterns of withdrawal, while some banks communicated with corporate clients on withdrawal schedules. (v) Zimbabwe commercial banks resumed the lending activity after dollarisation. Locally owned banks were aggressive, while foreign owned banks took a passive stance. There were problems with non-performing loans, especially from corporate clients, which exposed many banks to liquidity risk. (vi) Liquidity risk management in Zimbabwe was still guided by the Reserve Bank of Zimbabwe Risk Management Guideline BSD-04, 2007. All banks had liquidity risk management policies and procedure manuals but some banks were not adhering to them. Banks also had liquidity risk limits in place but some violated them. Furthermore, some banks were not conducting stress tests. Although all banks had contingency plans in place, none were testing them. Specifically, the research study highlighted the potential sources of liquidity risk in the Zimbabwean dollar and multiple currency periods. Based on the results, the study recommends survival strategies for banks in managing liquidity risk in such environments. It proposes a comprehensive liquidity management framework that clearly identifies, measures and control liquidity risk consistent with bank-specific and the country‟s macroeconomic developments. The envisaged framework would assist banks in dealing with illiquidity in a manner that would be less disruptive and that could render any future crisis less painful. Of importance is the recommendation that the central bank might not need to be too strict or too relaxed, but be moderate in ensuring an enabling regulatory environment. This would help banks to manage liquidity risk and at the same time protect depositors in any challenging operating environment. In both the studied time periods, there were transitory deposits. Generally there is need to inculcate a savings culture in Zimbabwe.
- Full Text:
- Date Issued: 2012
Literacy, orality and recontextualization in the parliament of the Republic of South Africa : an ethnographic study
- Authors: Siebörger, Ian
- Date: 2012
- Subjects: South Africa. Parliament (1994- ) -- Language , Bill drafting -- South Africa , South Africa -- Languages -- Political aspects , Sociolinguistics -- South Africa , Language and languages -- Variation , Linguistic analysis (Linguistics) , Functionalism (Linguistics) , Systemic grammar
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2384 , http://hdl.handle.net/10962/d1016140
- Description: In parliaments, the tasks of drafting legislation and conducting oversight are accomplished by means of complex chains of spoken, written and multimodal texts. In these genre chains, information is recontextualized from one text to another before being debated in sittings of the houses of parliament. This study employs the point of view afforded by linguistic ethnography to investigate critically the ways in which meanings are recontextualized in one section of such a genre chain, namely the process by which committees of South Africa's National Assembly oversee the budgets of government departments and state-owned entities. It does this to identify possible sources of communication difficulties in this process and suggest ways in which these can be minimized. In so doing, it develops a theoretical model of the discursive effects of recontextualization informed by Latour's (1987) notion of black-boxing as well as Maton's (2011) Legitimation Code Theory. This model uses Interactional Sociolinguistics and elements of Systemic Functional Linguistics, including APPRAISAL and Transitivity as tools to describe the realization of these effects in language. This study finds that ideational and interpersonal meanings are condensed and decondensed at particular points in the genre chain in ways that lead to some MPs’ voices being recontextualized more accurately than others’. It also shows that common sources of communication difficulties in the committee process include differences in political background and understandings of committee procedure and participant roles. It recommends that representatives of departments and entities reporting to the committees should receive a fuller prebriefing on their roles; that MPs should receive training on asking clear, focused questions; and that the role of committee secretaries as procedural advisors should be strengthened.
- Full Text:
- Date Issued: 2012
- Authors: Siebörger, Ian
- Date: 2012
- Subjects: South Africa. Parliament (1994- ) -- Language , Bill drafting -- South Africa , South Africa -- Languages -- Political aspects , Sociolinguistics -- South Africa , Language and languages -- Variation , Linguistic analysis (Linguistics) , Functionalism (Linguistics) , Systemic grammar
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2384 , http://hdl.handle.net/10962/d1016140
- Description: In parliaments, the tasks of drafting legislation and conducting oversight are accomplished by means of complex chains of spoken, written and multimodal texts. In these genre chains, information is recontextualized from one text to another before being debated in sittings of the houses of parliament. This study employs the point of view afforded by linguistic ethnography to investigate critically the ways in which meanings are recontextualized in one section of such a genre chain, namely the process by which committees of South Africa's National Assembly oversee the budgets of government departments and state-owned entities. It does this to identify possible sources of communication difficulties in this process and suggest ways in which these can be minimized. In so doing, it develops a theoretical model of the discursive effects of recontextualization informed by Latour's (1987) notion of black-boxing as well as Maton's (2011) Legitimation Code Theory. This model uses Interactional Sociolinguistics and elements of Systemic Functional Linguistics, including APPRAISAL and Transitivity as tools to describe the realization of these effects in language. This study finds that ideational and interpersonal meanings are condensed and decondensed at particular points in the genre chain in ways that lead to some MPs’ voices being recontextualized more accurately than others’. It also shows that common sources of communication difficulties in the committee process include differences in political background and understandings of committee procedure and participant roles. It recommends that representatives of departments and entities reporting to the committees should receive a fuller prebriefing on their roles; that MPs should receive training on asking clear, focused questions; and that the role of committee secretaries as procedural advisors should be strengthened.
- Full Text:
- Date Issued: 2012
Lithostratigraphic correlation, mineralogy and geochemistry of the lower manganese orebody at the Kalagadi Manganese Mine in the Northern Cape Province of South Africa
- Authors: Rasmeni, Sonwabile
- Date: 2012
- Subjects: Manganese mines and mining -- South Africa , Manganese ores -- Geology -- South Africa , Mineralogy -- South Africa , Geochemistry -- South Africa
- Language: English
- Type: Thesis , Masters , MSc (Geology)
- Identifier: vital:11526 , http://hdl.handle.net/10353/d1016155 , Manganese mines and mining -- South Africa , Manganese ores -- Geology -- South Africa , Mineralogy -- South Africa , Geochemistry -- South Africa
- Description: The Kalagadi Manganese mine in the Kuruman area of the Northern Cape Province of South Africa contains reserves of Mn ore in excess of 100Mt. Mineralization in the mine lease area is restricted within the Hotazel Formation of the Voȅlwater Subgroup, belonging to the Postmasburg Group, the upper subdivision of the Transvaal Supergroup. Surface topography is characterized by flat lying, undulation with minimal faulting and the ore are slightly metarmophosed. This study investigates the general geology of the mine, lithostratigraphic subdivision and correlation of the economic Lower Manganese Orebody (LMO) of the Kalagadi Manganese Mine in order to guide mining plan and operations once the mine is fully commissioned. At the commencement of this study, Kalagadi Manganese mine was a project under exploration with no specific geology of the mine lease area and no lithostratigraphic subdivision. The study also aimed determining the extent of lithostratigraphic correlation between the LMO economic orebodies of the Kalagadi Manganese mine with that of underground Gloria and open-pit Mamatwan mines. Four methods including petrographic microscope, Scanning electron Microscope (SEM), X-ray diffraction (XRD) and X-ray fluorescence (XRF) analyses were applied mainly for the mineral identification, chemical composition and ore characterization of the Lower Manganese Orebody (LMO) at Kalagadi Manganese mine. The results of this study indicates the following: (1) Eleven textural distinct zones with economic zones restricted to the middle while the lower grade zones are confined to the top and bottom of the LMO; (2) The economic zones, comprising of Y, M, C and N subzones attain an average thickness of 10 m and are graded at an average of 40% Mn while the Mn/Fe ratio varies from 6 to 9; (3) The most economic zones are M and N subzones which are mostly characterized by oxidized ovoids and laminae, a characteristic applicable even to other zones of economic interest; (4) Braunite is the main mineral of the manganese ore and is often integrown with kutnahorite and other minerals (hematite, hausmannite, Mg-calcite, calcite, jacobsite, serpentine and garnet) which are present in variable amounts; (5) The Mg-rich calcite (Ca, Mg)CO3 is the second dominant manganese carbonate mineral and it corresponds to elevated MgO concentration and is often associated with marine environment. The occurrence of the Mgcalcite is not common in the manganese ore of this area except for the Mn-calcite, which was not determined by XRD analyses in this study; (6) MnO is the most abundant major oxide in the manganese ore while other major oxides present in decreasing order of abundance are CaO, SiO2, Fe2O3, and MgO. The oxides TiO2, Na2O, K2O, Al2O3, and Cr2O3 are depleted and are mostly 0.01wt% and 0.001wt% respectively while P2O5 concentrations are low ranging from 0.02wt% to 0.3wt%. The trace element concentrations of Ba, Zn and Sr in most borehole samples are slightly elevated ranging from 100ppm to 3.9% (36000pm) while Co, Cu, Ni, Y, As, Zr, V and La rarely exceed 50ppm. The enrichments of Cu, Zn, Ni, Co and V that are commonly associated with volcanogenic hydrothermal input in chemicals may reach up to 70ppm; (7) The mineralogical and geochemical characteristics of the manganese ore in the Kalagadi Manganese mine lease area are similar to that of Low-Grade Mamatwan-Type ore. The cyclicity (Banded Iron Formation ↔ Hematite lutite ↔ braunite lutite) and alternation of manganese and iron formation have been confirmed; and (8) The oxygen δ18O isotope values (18‰ to 22‰) indicate a slight influence of metamorphism of the manganese ore. No positive correlation exists between δ13C vs δ18O values and Mn vs δ13C values. Such observations indicate minimal action of organic carbon during manganese precipitation where the organic matter was oxidized and manganese content reduced. On the other hand, the manganese carbonates (CaO) are positively correlated with carbon isotope, this indicates diagenetic alteration and the involvement of biogenic carbonate during the formation of manganese carbonates. It is concluded that the lithostratigraphic subdivision at Kalagadi Manganese mine is best correlated physically, mineralogically and geochemically with that of Gloria mine operating in the Low Grade Mamatwan - Type ore while correlation with an open-pit Mamatwan mine is also valid.
- Full Text:
- Date Issued: 2012
- Authors: Rasmeni, Sonwabile
- Date: 2012
- Subjects: Manganese mines and mining -- South Africa , Manganese ores -- Geology -- South Africa , Mineralogy -- South Africa , Geochemistry -- South Africa
- Language: English
- Type: Thesis , Masters , MSc (Geology)
- Identifier: vital:11526 , http://hdl.handle.net/10353/d1016155 , Manganese mines and mining -- South Africa , Manganese ores -- Geology -- South Africa , Mineralogy -- South Africa , Geochemistry -- South Africa
- Description: The Kalagadi Manganese mine in the Kuruman area of the Northern Cape Province of South Africa contains reserves of Mn ore in excess of 100Mt. Mineralization in the mine lease area is restricted within the Hotazel Formation of the Voȅlwater Subgroup, belonging to the Postmasburg Group, the upper subdivision of the Transvaal Supergroup. Surface topography is characterized by flat lying, undulation with minimal faulting and the ore are slightly metarmophosed. This study investigates the general geology of the mine, lithostratigraphic subdivision and correlation of the economic Lower Manganese Orebody (LMO) of the Kalagadi Manganese Mine in order to guide mining plan and operations once the mine is fully commissioned. At the commencement of this study, Kalagadi Manganese mine was a project under exploration with no specific geology of the mine lease area and no lithostratigraphic subdivision. The study also aimed determining the extent of lithostratigraphic correlation between the LMO economic orebodies of the Kalagadi Manganese mine with that of underground Gloria and open-pit Mamatwan mines. Four methods including petrographic microscope, Scanning electron Microscope (SEM), X-ray diffraction (XRD) and X-ray fluorescence (XRF) analyses were applied mainly for the mineral identification, chemical composition and ore characterization of the Lower Manganese Orebody (LMO) at Kalagadi Manganese mine. The results of this study indicates the following: (1) Eleven textural distinct zones with economic zones restricted to the middle while the lower grade zones are confined to the top and bottom of the LMO; (2) The economic zones, comprising of Y, M, C and N subzones attain an average thickness of 10 m and are graded at an average of 40% Mn while the Mn/Fe ratio varies from 6 to 9; (3) The most economic zones are M and N subzones which are mostly characterized by oxidized ovoids and laminae, a characteristic applicable even to other zones of economic interest; (4) Braunite is the main mineral of the manganese ore and is often integrown with kutnahorite and other minerals (hematite, hausmannite, Mg-calcite, calcite, jacobsite, serpentine and garnet) which are present in variable amounts; (5) The Mg-rich calcite (Ca, Mg)CO3 is the second dominant manganese carbonate mineral and it corresponds to elevated MgO concentration and is often associated with marine environment. The occurrence of the Mgcalcite is not common in the manganese ore of this area except for the Mn-calcite, which was not determined by XRD analyses in this study; (6) MnO is the most abundant major oxide in the manganese ore while other major oxides present in decreasing order of abundance are CaO, SiO2, Fe2O3, and MgO. The oxides TiO2, Na2O, K2O, Al2O3, and Cr2O3 are depleted and are mostly 0.01wt% and 0.001wt% respectively while P2O5 concentrations are low ranging from 0.02wt% to 0.3wt%. The trace element concentrations of Ba, Zn and Sr in most borehole samples are slightly elevated ranging from 100ppm to 3.9% (36000pm) while Co, Cu, Ni, Y, As, Zr, V and La rarely exceed 50ppm. The enrichments of Cu, Zn, Ni, Co and V that are commonly associated with volcanogenic hydrothermal input in chemicals may reach up to 70ppm; (7) The mineralogical and geochemical characteristics of the manganese ore in the Kalagadi Manganese mine lease area are similar to that of Low-Grade Mamatwan-Type ore. The cyclicity (Banded Iron Formation ↔ Hematite lutite ↔ braunite lutite) and alternation of manganese and iron formation have been confirmed; and (8) The oxygen δ18O isotope values (18‰ to 22‰) indicate a slight influence of metamorphism of the manganese ore. No positive correlation exists between δ13C vs δ18O values and Mn vs δ13C values. Such observations indicate minimal action of organic carbon during manganese precipitation where the organic matter was oxidized and manganese content reduced. On the other hand, the manganese carbonates (CaO) are positively correlated with carbon isotope, this indicates diagenetic alteration and the involvement of biogenic carbonate during the formation of manganese carbonates. It is concluded that the lithostratigraphic subdivision at Kalagadi Manganese mine is best correlated physically, mineralogically and geochemically with that of Gloria mine operating in the Low Grade Mamatwan - Type ore while correlation with an open-pit Mamatwan mine is also valid.
- Full Text:
- Date Issued: 2012
Living lab methodology as an approach to innovation in ICT4D: The Siyakhula Living Lab experience
- Gumbo, Sibukelo, Thinyane, Hannah, Thinyane, Mamello, Terzoli, Alfredo, Hansen, Susan
- Authors: Gumbo, Sibukelo , Thinyane, Hannah , Thinyane, Mamello , Terzoli, Alfredo , Hansen, Susan
- Date: 2012
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/431302 , vital:72762 , https://www.siyakhulall.com/sites/default/files/ISTAfrica_Paper_ref_18_doc_4809_0.pdf
- Description: Underdevelopment and poverty represent key challenges faced by the modern world, which have attracted the attention of NGOs, civil society, government and multinationals. Various undertakings including the United Nations Millennium Development Goals articulation and the World Summit on Information Society highlight the global commitment towards addressing these problems. The solutions to these problems should be derived out of well-structured innovation systems that take into consideration the grassroot context and concerns. A number of in-novation models have been formulated and utilized effectively in differ-ent industries, and some of these have equally been used effectively in community development contexts. This paper elaborates on the Living Lab methodology and its application in ICT4D contexts, highlighting the effectiveness of this model towards integrating end-users within their problem solving effort. This is discussed through the backdrop of the Siyakhula Living Lab, an ICT4D intervention. The embedding environ-ment for this model, which enables key synergies with other stakehold-ers, is also discussed.
- Full Text:
- Date Issued: 2012
- Authors: Gumbo, Sibukelo , Thinyane, Hannah , Thinyane, Mamello , Terzoli, Alfredo , Hansen, Susan
- Date: 2012
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/431302 , vital:72762 , https://www.siyakhulall.com/sites/default/files/ISTAfrica_Paper_ref_18_doc_4809_0.pdf
- Description: Underdevelopment and poverty represent key challenges faced by the modern world, which have attracted the attention of NGOs, civil society, government and multinationals. Various undertakings including the United Nations Millennium Development Goals articulation and the World Summit on Information Society highlight the global commitment towards addressing these problems. The solutions to these problems should be derived out of well-structured innovation systems that take into consideration the grassroot context and concerns. A number of in-novation models have been formulated and utilized effectively in differ-ent industries, and some of these have equally been used effectively in community development contexts. This paper elaborates on the Living Lab methodology and its application in ICT4D contexts, highlighting the effectiveness of this model towards integrating end-users within their problem solving effort. This is discussed through the backdrop of the Siyakhula Living Lab, an ICT4D intervention. The embedding environ-ment for this model, which enables key synergies with other stakehold-ers, is also discussed.
- Full Text:
- Date Issued: 2012
Living with HIV/AIDS in King Williams Town, Eastern Cape
- Authors: Chinyama, Ephraim
- Date: 2012
- Subjects: AIDS (Disease) -- South Africa -- Eastern Cape , HIV-positive persons -- South Africa -- Eastern Cape , HIV-positive persons -- Social aspects -- South Africa -- Eastern Cape , King William's Town (South Africa)
- Language: English
- Type: Thesis , Masters , M Soc Sc (Rural Development)
- Identifier: vital:11956 , http://hdl.handle.net/10353/d1005964 , AIDS (Disease) -- South Africa -- Eastern Cape , HIV-positive persons -- South Africa -- Eastern Cape , HIV-positive persons -- Social aspects -- South Africa -- Eastern Cape , King William's Town (South Africa)
- Description: This study examines the lifestyle decisions of people who are diagnosed with HIV/AIDS in King Williams Town, Eastern Cape. The study was motivated by the ever growing number of people who are now living with HIV/AIDS. Therefore the researcher intended to examine their decisions regarding sexual choices, reproductive health, diet, physical fitness and their coping strategies. The study found that there is very low uptake of Voluntary Counseling and Testing (VCT). Most people only get tested if they are compelled by other factors, like illness and pregnancy. It also found that HIV positive people continue to engage in risky sexual behaviour regardless of their positive status. In addition it also found that HIV positive status does not affect sexual activity and social support from family and friends is a very important factor that is helping the respondents to cope with HIV diagnosis.
- Full Text:
- Date Issued: 2012
- Authors: Chinyama, Ephraim
- Date: 2012
- Subjects: AIDS (Disease) -- South Africa -- Eastern Cape , HIV-positive persons -- South Africa -- Eastern Cape , HIV-positive persons -- Social aspects -- South Africa -- Eastern Cape , King William's Town (South Africa)
- Language: English
- Type: Thesis , Masters , M Soc Sc (Rural Development)
- Identifier: vital:11956 , http://hdl.handle.net/10353/d1005964 , AIDS (Disease) -- South Africa -- Eastern Cape , HIV-positive persons -- South Africa -- Eastern Cape , HIV-positive persons -- Social aspects -- South Africa -- Eastern Cape , King William's Town (South Africa)
- Description: This study examines the lifestyle decisions of people who are diagnosed with HIV/AIDS in King Williams Town, Eastern Cape. The study was motivated by the ever growing number of people who are now living with HIV/AIDS. Therefore the researcher intended to examine their decisions regarding sexual choices, reproductive health, diet, physical fitness and their coping strategies. The study found that there is very low uptake of Voluntary Counseling and Testing (VCT). Most people only get tested if they are compelled by other factors, like illness and pregnancy. It also found that HIV positive people continue to engage in risky sexual behaviour regardless of their positive status. In addition it also found that HIV positive status does not affect sexual activity and social support from family and friends is a very important factor that is helping the respondents to cope with HIV diagnosis.
- Full Text:
- Date Issued: 2012
Local government reform in Western Australia: a case study on change readiness
- Authors: Van Heerden, Vicky
- Date: 2012
- Subjects: Local government -- Australia -- Nedlands (W.A.) Local government -- Australia -- Subiaco (W.A.) Organizational change -- Australia -- Nedlands (W.A.) Local officials and employees -- Australia -- Nedlands (W.A.) Industrial relations -- Australia -- Nedlands (W.A.) Industrial management -- Australia -- Nedlands (W.A.) Corporate culture -- Australia -- Nedlands (W.A.)
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:776 , http://hdl.handle.net/10962/d1003897
- Description: The Western Australian State Government’s local government reform programme, initiated in February 2009, provides the context for this research. Nedlands, a local government in Perth’s western suburbs, resolved to participate in this reform programme and signed a Regional Transition Group Agreement with Subiaco local government in August 2010. The purpose of the Regional Transition Group was to prepare a business plan to investigate the potential benefits and viability of a Nedlands and Subiaco amalgamation. Whilst the local government of Nedlands is currently investigating the more operational and technical aspects of local government reform in the merger feasibility study, this research focused on employee readiness, more intangible but no less important. The difficulties of achieving success with organisational change initiatives are well documented. A number of models of planned organisational change have been developed to address these difficulties and support successful change and are outlined. This research highlights the value of the first phase of planned change, namely readiness for change, where organizational members are prepared for and become supporters of change. It also highlights the importance of change communication with respect to developing employee readiness. Definitions and some of the dimensions of ‘readiness for change’ are outlined. The five dimensions of readiness for change - discrepancy, appropriateness, principal support, efficacy and valence - provide the ‘lens’ through which readiness for change at Nedlands is explored. From this perspective, the documentation communicating local government reform at Nedlands was analysed. These dimensions were also used to ascertain, from the perspective of the Nedlands' managers, their level of readiness and the readiness of the employees of Nedlands for local government reform. The findings suggest that Nedlands local government has not consciously planned to ‘ready’ employees for local government reform. A number of management recommendations are made to strengthen the change readiness message communicated by the Nedlands local government and to support the development of the Nedlands employees’ readiness for change.
- Full Text:
- Date Issued: 2012
- Authors: Van Heerden, Vicky
- Date: 2012
- Subjects: Local government -- Australia -- Nedlands (W.A.) Local government -- Australia -- Subiaco (W.A.) Organizational change -- Australia -- Nedlands (W.A.) Local officials and employees -- Australia -- Nedlands (W.A.) Industrial relations -- Australia -- Nedlands (W.A.) Industrial management -- Australia -- Nedlands (W.A.) Corporate culture -- Australia -- Nedlands (W.A.)
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:776 , http://hdl.handle.net/10962/d1003897
- Description: The Western Australian State Government’s local government reform programme, initiated in February 2009, provides the context for this research. Nedlands, a local government in Perth’s western suburbs, resolved to participate in this reform programme and signed a Regional Transition Group Agreement with Subiaco local government in August 2010. The purpose of the Regional Transition Group was to prepare a business plan to investigate the potential benefits and viability of a Nedlands and Subiaco amalgamation. Whilst the local government of Nedlands is currently investigating the more operational and technical aspects of local government reform in the merger feasibility study, this research focused on employee readiness, more intangible but no less important. The difficulties of achieving success with organisational change initiatives are well documented. A number of models of planned organisational change have been developed to address these difficulties and support successful change and are outlined. This research highlights the value of the first phase of planned change, namely readiness for change, where organizational members are prepared for and become supporters of change. It also highlights the importance of change communication with respect to developing employee readiness. Definitions and some of the dimensions of ‘readiness for change’ are outlined. The five dimensions of readiness for change - discrepancy, appropriateness, principal support, efficacy and valence - provide the ‘lens’ through which readiness for change at Nedlands is explored. From this perspective, the documentation communicating local government reform at Nedlands was analysed. These dimensions were also used to ascertain, from the perspective of the Nedlands' managers, their level of readiness and the readiness of the employees of Nedlands for local government reform. The findings suggest that Nedlands local government has not consciously planned to ‘ready’ employees for local government reform. A number of management recommendations are made to strengthen the change readiness message communicated by the Nedlands local government and to support the development of the Nedlands employees’ readiness for change.
- Full Text:
- Date Issued: 2012
Long-term catch and effort trends in Eastern Cape Angling Week competitions
- Dicken, Matthew L, Smale, Malcolm J, Booth, Anthony J
- Authors: Dicken, Matthew L , Smale, Malcolm J , Booth, Anthony J
- Date: 2012
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/124931 , vital:35711 , https://doi.org/10.2989/1814232X.2012.709961
- Description: Recreational shore-based angling is one of the most popular sport and outdoor activity pastimes in South Africa with an estimated 412 000 fishers (McGrath et al. 1997). It is a form of linefishing where fish are caught using a hook and line and comprises a social as well as a more formal organized competitive sector (van der Elst 1989). Similar to other components of the linefishery, which include the subsistence as well as boat-based commercial sectors, excessive shore-fishing effort along the Eastern Cape has resulted not only in declining catches (Bennett 1991, Griffiths 1997, Brouwer and Buxton 2002, Pradervand and Govender 2003) but also changes in the species composition of catches (Bennett et al. 1994, Brouwer et al. 1997, Attwood and Farquhar 1999). Stock assessments indicate that many important linefish species are severely overexploited (Griffiths 1997, Hutchings 2000, Mann 2000) and that continued fishing pressure threatens endemic linefish populations. In 1996, shore-anglers alone were responsible for an annual catch of approximately 4.5 million fish, weighing around 3 000 tonnes (Brouwer et al. 1997).
- Full Text:
- Date Issued: 2012
- Authors: Dicken, Matthew L , Smale, Malcolm J , Booth, Anthony J
- Date: 2012
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/124931 , vital:35711 , https://doi.org/10.2989/1814232X.2012.709961
- Description: Recreational shore-based angling is one of the most popular sport and outdoor activity pastimes in South Africa with an estimated 412 000 fishers (McGrath et al. 1997). It is a form of linefishing where fish are caught using a hook and line and comprises a social as well as a more formal organized competitive sector (van der Elst 1989). Similar to other components of the linefishery, which include the subsistence as well as boat-based commercial sectors, excessive shore-fishing effort along the Eastern Cape has resulted not only in declining catches (Bennett 1991, Griffiths 1997, Brouwer and Buxton 2002, Pradervand and Govender 2003) but also changes in the species composition of catches (Bennett et al. 1994, Brouwer et al. 1997, Attwood and Farquhar 1999). Stock assessments indicate that many important linefish species are severely overexploited (Griffiths 1997, Hutchings 2000, Mann 2000) and that continued fishing pressure threatens endemic linefish populations. In 1996, shore-anglers alone were responsible for an annual catch of approximately 4.5 million fish, weighing around 3 000 tonnes (Brouwer et al. 1997).
- Full Text:
- Date Issued: 2012
Lost in translation: Transformation in the first round of institutional audits
- Authors: McKenna, Sioux , Quinn, Lynn
- Date: 2012
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/187384 , vital:44627 , xlink:href="https://hdl.handle.net/10520/EJC132752"
- Description: The South African higher education institutional audit process was introduced alongside similar endeavors internationally. However, despite many similarities, each country foregrounds different concerns within their higher education quality processes. In their seminal article, Harvey and Green suggest five possible notions of quality, one of which is quality as transformation, and in South Africa the message has been clearly stated: notions of quality are intricately related to transformation. Local research has however suggested that the notion of 'transformation' as quality takes on particular nuances within the country’s context. In the two institutional case studies presented here, the 'quality as transformation' discourse appears to have been largely lost in translation. In one university transformation was not called upon to construct notions of quality; quality was primarily constructed by a discourse of excellence. In the other institution, the transformation aspects of quality seem to have been interpreted in a particularly reductionist way as relating solely to racial demographics. In both cases, this article argues that the 'quality as transformation' discourse prevalent in the audit documentation in the South African context was lost somewhere between the intentions embodied in national documents and the processes embarked upon by institutions.
- Full Text:
- Date Issued: 2012
- Authors: McKenna, Sioux , Quinn, Lynn
- Date: 2012
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/187384 , vital:44627 , xlink:href="https://hdl.handle.net/10520/EJC132752"
- Description: The South African higher education institutional audit process was introduced alongside similar endeavors internationally. However, despite many similarities, each country foregrounds different concerns within their higher education quality processes. In their seminal article, Harvey and Green suggest five possible notions of quality, one of which is quality as transformation, and in South Africa the message has been clearly stated: notions of quality are intricately related to transformation. Local research has however suggested that the notion of 'transformation' as quality takes on particular nuances within the country’s context. In the two institutional case studies presented here, the 'quality as transformation' discourse appears to have been largely lost in translation. In one university transformation was not called upon to construct notions of quality; quality was primarily constructed by a discourse of excellence. In the other institution, the transformation aspects of quality seem to have been interpreted in a particularly reductionist way as relating solely to racial demographics. In both cases, this article argues that the 'quality as transformation' discourse prevalent in the audit documentation in the South African context was lost somewhere between the intentions embodied in national documents and the processes embarked upon by institutions.
- Full Text:
- Date Issued: 2012
Love Interrupted (Short story anthology)
- Authors: Malatji, Reneilwe
- Date: 2012
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:21016 , http://hdl.handle.net/10962/6004
- Description: This collection of stories focuses on struggles between black South African men and women. Several of the stories explore how the rise of the affluent and powerful black woman is redefining relationships. Other stories in the collection describe women who do not know how to free themselves from their subservient role, or do not want to. Issues of interracial relations between blacks and whites in contemporary South Africa also feature in most of the stories.
- Full Text:
- Date Issued: 2012
- Authors: Malatji, Reneilwe
- Date: 2012
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:21016 , http://hdl.handle.net/10962/6004
- Description: This collection of stories focuses on struggles between black South African men and women. Several of the stories explore how the rise of the affluent and powerful black woman is redefining relationships. Other stories in the collection describe women who do not know how to free themselves from their subservient role, or do not want to. Issues of interracial relations between blacks and whites in contemporary South Africa also feature in most of the stories.
- Full Text:
- Date Issued: 2012
Love thy neighbour : group properties of gaping behaviour in mussel aggregations
- Nicastro, Katy R, Zardi, Gerardo I, McQuaid, Christopher D, Pearson, Gareth A, Serrão, Ester A
- Authors: Nicastro, Katy R , Zardi, Gerardo I , McQuaid, Christopher D , Pearson, Gareth A , Serrão, Ester A
- Date: 2012
- Language: English
- Type: Article
- Identifier: vital:6841 , http://hdl.handle.net/10962/d1010991
- Description: By associating closely with others to form a group, an animal can benefit from a number of advantages including reduced risk of predation, amelioration of environmental conditions, and increased reproductive success, but at the price of reduced resources. Although made up of individual members, an aggregation often displays novel effects that do not manifest at the level of the individual organism. Here we show that very simple behaviour in intertidal mussels shows new effects in dense aggregations but not in isolated individuals. Perna perna and Mytilus galloprovincialis are gaping (periodic valve movement during emersion) and non-gaping mussels respectively. P. perna gaping behaviour had no effect on body temperatures of isolated individuals, while it led to increased humidity and decreased temperatures in dense groups (beds). Gaping resulted in cooler body temperatures for P. perna than M. galloprovincialis when in aggregations, while solitary individuals exhibited the highest temperatures. Gradients of increasing body temperature were detected from the center to edges of beds, but M. galloprovincialis at the edge had the same temperature as isolated individuals. Furthermore, a field study showed that during periods of severe heat stress, mortality rates of mussels within beds of the gaping P. perna were lower than those of isolated individuals or within beds of M. galloprovincialis, highlighting the determinant role of gaping on fitness and group functioning. We demonstrate that new effects of very simple individual behaviour lead to amelioration of abiotic conditions at the aggregation level and that these effects increase mussel resistance to thermal stress.
- Full Text:
- Date Issued: 2012
- Authors: Nicastro, Katy R , Zardi, Gerardo I , McQuaid, Christopher D , Pearson, Gareth A , Serrão, Ester A
- Date: 2012
- Language: English
- Type: Article
- Identifier: vital:6841 , http://hdl.handle.net/10962/d1010991
- Description: By associating closely with others to form a group, an animal can benefit from a number of advantages including reduced risk of predation, amelioration of environmental conditions, and increased reproductive success, but at the price of reduced resources. Although made up of individual members, an aggregation often displays novel effects that do not manifest at the level of the individual organism. Here we show that very simple behaviour in intertidal mussels shows new effects in dense aggregations but not in isolated individuals. Perna perna and Mytilus galloprovincialis are gaping (periodic valve movement during emersion) and non-gaping mussels respectively. P. perna gaping behaviour had no effect on body temperatures of isolated individuals, while it led to increased humidity and decreased temperatures in dense groups (beds). Gaping resulted in cooler body temperatures for P. perna than M. galloprovincialis when in aggregations, while solitary individuals exhibited the highest temperatures. Gradients of increasing body temperature were detected from the center to edges of beds, but M. galloprovincialis at the edge had the same temperature as isolated individuals. Furthermore, a field study showed that during periods of severe heat stress, mortality rates of mussels within beds of the gaping P. perna were lower than those of isolated individuals or within beds of M. galloprovincialis, highlighting the determinant role of gaping on fitness and group functioning. We demonstrate that new effects of very simple individual behaviour lead to amelioration of abiotic conditions at the aggregation level and that these effects increase mussel resistance to thermal stress.
- Full Text:
- Date Issued: 2012
M 87 at metre wavelengths: the LOFAR picture
- Smirnov, Oleg M, De Gasperin, F, Orrú, E, Murgia, M, Merloni, A, Falcke, H, Beck, R, Beswick, R, Bîrzan, L, Bonafede, A, Brüggen, M
- Authors: Smirnov, Oleg M , De Gasperin, F , Orrú, E , Murgia, M , Merloni, A , Falcke, H , Beck, R , Beswick, R , Bîrzan, L , Bonafede, A , Brüggen, M
- Date: 2012
- Subjects: radiation mechanisms: non-thermal, galaxies: active, galaxies: individual: M 87, galaxies: clusters: individual: Virgo, galaxies: jets, radio continuum: galaxies
- Language: English
- Type: Article
- Identifier: vital:6821 , http://hdl.handle.net/10962/d1004434
- Description: Context.M 87 is a giant elliptical galaxy located in the centre of the Virgo cluster, which harbours a supermassive black hole of mass 6.4 × 109 M⊙, whose activity is responsible for the extended (80 kpc) radio lobes that surround the galaxy. The energy generated by matter falling onto the central black hole is ejected and transferred to the intra-cluster medium via a relativistic jet and morphologically complex systems of buoyant bubbles, which rise towards the edges of the extended halo. Aims. To place constraints on past activity cycles of the active nucleus, images of M 87 were produced at low radio frequencies never explored before at these high spatial resolution and dynamic range. To disentangle different synchrotron models and place constraints on source magnetic field, age and energetics, we also performed a detailed spectral analysis of M 87 extended radio-halo. Methods. We present the first observations made with the new Low-Frequency Array (LOFAR) of M 87 at frequencies down to 20 MHz. Three observations were conducted, at 15−30 MHz, 30−77 MHz and 116−162 MHz. We used these observations together with archival data to produce a low-frequency spectral index map and to perform a spectral analysis in the wide frequency range 30 MHz–10 GHz. Results. We do not find any sign of new extended emissions; on the contrary the source appears well confined by the high pressure of the intra-cluster medium. A continuous injection of relativistic electrons is the model that best fits our data, and provides a scenario in which the lobes are still supplied by fresh relativistic particles from the active galactic nuclei. We suggest that the discrepancy between the low-frequency radio-spectral slope in the core and in the halo implies a strong adiabatic expansion of the plasma as soon as it leaves the core area. The extended halo has an equipartition magnetic field strength of ≃10 μG, which increases to ≃13 μG in the zones where the particle flows are more active. The continuous injection model for synchrotron ageing provides an age for the halo of ≃40 Myr, which in turn provides a jet kinetic power of 6−10 × 1044 erg s-1.
- Full Text:
- Date Issued: 2012
- Authors: Smirnov, Oleg M , De Gasperin, F , Orrú, E , Murgia, M , Merloni, A , Falcke, H , Beck, R , Beswick, R , Bîrzan, L , Bonafede, A , Brüggen, M
- Date: 2012
- Subjects: radiation mechanisms: non-thermal, galaxies: active, galaxies: individual: M 87, galaxies: clusters: individual: Virgo, galaxies: jets, radio continuum: galaxies
- Language: English
- Type: Article
- Identifier: vital:6821 , http://hdl.handle.net/10962/d1004434
- Description: Context.M 87 is a giant elliptical galaxy located in the centre of the Virgo cluster, which harbours a supermassive black hole of mass 6.4 × 109 M⊙, whose activity is responsible for the extended (80 kpc) radio lobes that surround the galaxy. The energy generated by matter falling onto the central black hole is ejected and transferred to the intra-cluster medium via a relativistic jet and morphologically complex systems of buoyant bubbles, which rise towards the edges of the extended halo. Aims. To place constraints on past activity cycles of the active nucleus, images of M 87 were produced at low radio frequencies never explored before at these high spatial resolution and dynamic range. To disentangle different synchrotron models and place constraints on source magnetic field, age and energetics, we also performed a detailed spectral analysis of M 87 extended radio-halo. Methods. We present the first observations made with the new Low-Frequency Array (LOFAR) of M 87 at frequencies down to 20 MHz. Three observations were conducted, at 15−30 MHz, 30−77 MHz and 116−162 MHz. We used these observations together with archival data to produce a low-frequency spectral index map and to perform a spectral analysis in the wide frequency range 30 MHz–10 GHz. Results. We do not find any sign of new extended emissions; on the contrary the source appears well confined by the high pressure of the intra-cluster medium. A continuous injection of relativistic electrons is the model that best fits our data, and provides a scenario in which the lobes are still supplied by fresh relativistic particles from the active galactic nuclei. We suggest that the discrepancy between the low-frequency radio-spectral slope in the core and in the halo implies a strong adiabatic expansion of the plasma as soon as it leaves the core area. The extended halo has an equipartition magnetic field strength of ≃10 μG, which increases to ≃13 μG in the zones where the particle flows are more active. The continuous injection model for synchrotron ageing provides an age for the halo of ≃40 Myr, which in turn provides a jet kinetic power of 6−10 × 1044 erg s-1.
- Full Text:
- Date Issued: 2012
Macroeconomic determinants of stock market behaviour in South Africa
- Authors: Junkin, Kyle
- Date: 2012
- Subjects: Stocks -- Prices -- South Africa Macroeconomics Risk management -- South Africa Stock exchanges -- South Africa Interest rates -- South Africa
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:1016 , http://hdl.handle.net/10962/d1002751
- Description: This study investigates whether stock prices in South Africa are influenced by macroeconomic variables, and furthermore, the effects of financial crises on stock prices. The relationship between stock prices and the macroeconomy is a particularly important issue for investors, since a thorough understanding of such a relationship is likely to yield profitable or risk mitigating opportunities. Using monthly data for the period 1995 to 2010 the study focused at a macro level using the FTSE/JSE All Share Index, and at a micro level using sector indices. These included the construction and materials, financial, food producers’, general retailers, industrial, mining and pharmaceuticals indices. The Johansen and Juselius (1990) multivariate cointegration approach was employed, along with impulse response and variance decomposition tests to address the issue. The results showed that macroeconomic variables do have a significant influence on stock prices in South Africa. Also, the influences of these variables were found to have an inconsistent effect across the sectors under investigation. For example, inflation was found to negatively influence the All Share Index, but impacted the industrial index positively. These inconsistent influences on the various sectors were seen to have important diversification implications for investors. The impact of past financial crises proved to be significant on certain indices, however, indices such as that of the pharmaceuticals sector was found to be largely unaffected by such crises. The findings of the study were discussed through an investor’s perspective, and recommendations on investment decisions were given. The limitations of the study were such that certain results may have been influenced by a mis-specification of variables, particularly the Treasury bill rate.
- Full Text:
- Date Issued: 2012
- Authors: Junkin, Kyle
- Date: 2012
- Subjects: Stocks -- Prices -- South Africa Macroeconomics Risk management -- South Africa Stock exchanges -- South Africa Interest rates -- South Africa
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:1016 , http://hdl.handle.net/10962/d1002751
- Description: This study investigates whether stock prices in South Africa are influenced by macroeconomic variables, and furthermore, the effects of financial crises on stock prices. The relationship between stock prices and the macroeconomy is a particularly important issue for investors, since a thorough understanding of such a relationship is likely to yield profitable or risk mitigating opportunities. Using monthly data for the period 1995 to 2010 the study focused at a macro level using the FTSE/JSE All Share Index, and at a micro level using sector indices. These included the construction and materials, financial, food producers’, general retailers, industrial, mining and pharmaceuticals indices. The Johansen and Juselius (1990) multivariate cointegration approach was employed, along with impulse response and variance decomposition tests to address the issue. The results showed that macroeconomic variables do have a significant influence on stock prices in South Africa. Also, the influences of these variables were found to have an inconsistent effect across the sectors under investigation. For example, inflation was found to negatively influence the All Share Index, but impacted the industrial index positively. These inconsistent influences on the various sectors were seen to have important diversification implications for investors. The impact of past financial crises proved to be significant on certain indices, however, indices such as that of the pharmaceuticals sector was found to be largely unaffected by such crises. The findings of the study were discussed through an investor’s perspective, and recommendations on investment decisions were given. The limitations of the study were such that certain results may have been influenced by a mis-specification of variables, particularly the Treasury bill rate.
- Full Text:
- Date Issued: 2012
Macrophyte distribution and responses to drought in the St Lucia Estuary
- Nondoda, Sibulele Phefumlela
- Authors: Nondoda, Sibulele Phefumlela
- Date: 2012
- Subjects: Estuaries -- South Africa -- Saint Lucia, Lake , Lakes -- South Africa -- Saint Lucia, Lake , Vegetation mapping -- South Africa -- Saint Lucia, Lake , Estuarine sediments -- South Africa -- Saint Lucia, Lake , Wetland mapping -- South Africa --Saint Lucia, Lake
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10632 , http://hdl.handle.net/10948/d1012330 , Estuaries -- South Africa -- Saint Lucia, Lake , Lakes -- South Africa -- Saint Lucia, Lake , Vegetation mapping -- South Africa -- Saint Lucia, Lake , Estuarine sediments -- South Africa -- Saint Lucia, Lake , Wetland mapping -- South Africa --Saint Lucia, Lake
- Description: This study investigated the response of the macrophytes in St Lucia Estuary, northern KwaZulu-Natal to drought. The present distribution of vegetation (2010 / 2011) was mapped and changes over time recorded from past aerial photographs. The changes in macrophyte cover in response to environmental factors (sediment and groundwater characteristics) was measured along four transects in 2010 and compared with results from previous years, in 2005 and 2006. In the current study, 1960 images were digitized to illustrate macrophyte distribution and cover of the Narrows, Makakatana and the Eastern Shores during a low rainfall period which started in 1958. The 2001 images were digitized to illustrate vegetation distribution and cover of the same area prior to the current drought which started in June/ July 2002. The 2008 images were digitized to illustrate vegetation distribution and cover of estuarine vegetation within the floodplain during the drought (after 6 years). The sites were visited in June 2011 for verification of the distribution and boundaries of each macrophyte habitat. The area covered by the water column varied over time. In 1960 during a low rainfall period the water was 32705 ha, 33320 ha in 2001 and reduced to 30443 ha in 2008. The area cover of inundated and dry reeds fluctuated with the water level. Under high water levels, low-lying areas such as Fanies Island and Selley‟s Lake were flooded and under low water levels, intertidal sand and mudflats were exposed and colonised by succulent salt marsh (Sarcocornia spp. and Salicornia meyeriana). Similar conditions were observed at Makakatana. Mangroves were observed from the mouth to the Forks. Avicennia marina was the dominant mangrove species and primary colonizer of dredge spoil. The area cover of mangroves in the vicinity of the mouth fluctuated as a result of fluctuating water levels, dredging operations, excavation of the Back Channel and Cyclone Gamede which killed intertidal vegetation. Between 2001 and 2008, mangrove expansion was faster in the Mfolozi Swamps area (± 1.4 ha yr -1) compared to the Narrows (± 0.4 ha yr -1). Long term monitoring transects were set up in 2005, at Makakatana, Charters Creek, Catalina Bay and at Listers Point to document changes in sediment conditions and vegetation cover. These were sampled in July 2005, October 2005, February 2006 and May 2010. Silt was the dominant particle size at Catalina Bay, Charters Creek and Makakatana. At Makakatana, average ground water salinity was 17.2 ± 6.6 ppt, 4.1± 4.9 ppt at Catalina Bay and 32.9 ± 19.3 ppt at Charters Creek. Drought resulted in the accumulation of salt on the surface sediment layer at Listers Point and Charters Creek due to low rainfall. Listers Point, the site with the lowest freshwater input and habitat diversity had the lowest macrophyte species richness with only three species. The dominant species at this site were Sporobolus virginicus and Chenopodium album L. which are highly salt tolerant species. Catalina Bay had the highest species richness (18 to 27); as a result of freshwater input via groundwater seepage from the sand dune aquifers on the Eastern Shores. Along the Eastern Shores, vegetation was dominated by species of Cyperaceae, Juncaceae and Juncaginaceae. Fluctuations in groundwater depth were observed at all sites, Listers Point groundwater depth in February 2006 was 80 cm and the ground water level was not reached during the May 2010 field trip. During the May 2010 field trip, the water column salinity of the St Lucia system was highly variable, Makakatana had the lowest water column salinity of 7.1 ppt, 42.1 ppt at Catalina Bay, 44 ppt at Charters Creek and Listers Point had the highest water column salinity of 95 ppt. An assessment of the changes in macrophyte cover along the transects showed that cover fluctuated in response to rainfall, water level and drought. At Listers Point, there was a continuous decline in the abundance of Sporobolus virginicus over time which was sparsely distributed in the first 40 m of the transect. Sarcocornia natalensis, a succulent and obligate halophyte, was recorded, in areas with high sediment conductivity. In May 2010, bare ground increased to an average percentage cover of 96.5% and was covered with dead organic matter and a salt crust at Listers Point. At Makakatana, there was a significant decrease in bare ground from July 2005 to May 2010 (H = 24.58, N = 197, p<0.001) as bare areas were colonized by salt marsh. Multivariate analysis showed that the abundance of Sporobolus virginicus was positively influenced by sediment moisture content and Paspalum vaginatum abundance was strongly influenced by the water column salinity. At Catalina Bay, low sediment conductivity at the groundwater seepage area resulted in terrestrial vegetation encroaching on estuarine vegetation. Sarcocornia natalensis became more abundant towards the water column. During the period of study, species richness at St Lucia ranged from 2 (Listers Point, May 2010) to 27 (Catalina Bay, February 2006). Salinity and water level fluctuation have a significant impact on the distribution of macrophytes at St Lucia during the drought. In saline areas salt marsh plants have colonized exposed shorelines and along the Eastern Shores groundwater seepage has increased macrophyte species richness. Low water levels have resulted in the exposure and desiccation of submerged macrophytes, which are replaced by macroalgae.
- Full Text:
- Date Issued: 2012
- Authors: Nondoda, Sibulele Phefumlela
- Date: 2012
- Subjects: Estuaries -- South Africa -- Saint Lucia, Lake , Lakes -- South Africa -- Saint Lucia, Lake , Vegetation mapping -- South Africa -- Saint Lucia, Lake , Estuarine sediments -- South Africa -- Saint Lucia, Lake , Wetland mapping -- South Africa --Saint Lucia, Lake
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10632 , http://hdl.handle.net/10948/d1012330 , Estuaries -- South Africa -- Saint Lucia, Lake , Lakes -- South Africa -- Saint Lucia, Lake , Vegetation mapping -- South Africa -- Saint Lucia, Lake , Estuarine sediments -- South Africa -- Saint Lucia, Lake , Wetland mapping -- South Africa --Saint Lucia, Lake
- Description: This study investigated the response of the macrophytes in St Lucia Estuary, northern KwaZulu-Natal to drought. The present distribution of vegetation (2010 / 2011) was mapped and changes over time recorded from past aerial photographs. The changes in macrophyte cover in response to environmental factors (sediment and groundwater characteristics) was measured along four transects in 2010 and compared with results from previous years, in 2005 and 2006. In the current study, 1960 images were digitized to illustrate macrophyte distribution and cover of the Narrows, Makakatana and the Eastern Shores during a low rainfall period which started in 1958. The 2001 images were digitized to illustrate vegetation distribution and cover of the same area prior to the current drought which started in June/ July 2002. The 2008 images were digitized to illustrate vegetation distribution and cover of estuarine vegetation within the floodplain during the drought (after 6 years). The sites were visited in June 2011 for verification of the distribution and boundaries of each macrophyte habitat. The area covered by the water column varied over time. In 1960 during a low rainfall period the water was 32705 ha, 33320 ha in 2001 and reduced to 30443 ha in 2008. The area cover of inundated and dry reeds fluctuated with the water level. Under high water levels, low-lying areas such as Fanies Island and Selley‟s Lake were flooded and under low water levels, intertidal sand and mudflats were exposed and colonised by succulent salt marsh (Sarcocornia spp. and Salicornia meyeriana). Similar conditions were observed at Makakatana. Mangroves were observed from the mouth to the Forks. Avicennia marina was the dominant mangrove species and primary colonizer of dredge spoil. The area cover of mangroves in the vicinity of the mouth fluctuated as a result of fluctuating water levels, dredging operations, excavation of the Back Channel and Cyclone Gamede which killed intertidal vegetation. Between 2001 and 2008, mangrove expansion was faster in the Mfolozi Swamps area (± 1.4 ha yr -1) compared to the Narrows (± 0.4 ha yr -1). Long term monitoring transects were set up in 2005, at Makakatana, Charters Creek, Catalina Bay and at Listers Point to document changes in sediment conditions and vegetation cover. These were sampled in July 2005, October 2005, February 2006 and May 2010. Silt was the dominant particle size at Catalina Bay, Charters Creek and Makakatana. At Makakatana, average ground water salinity was 17.2 ± 6.6 ppt, 4.1± 4.9 ppt at Catalina Bay and 32.9 ± 19.3 ppt at Charters Creek. Drought resulted in the accumulation of salt on the surface sediment layer at Listers Point and Charters Creek due to low rainfall. Listers Point, the site with the lowest freshwater input and habitat diversity had the lowest macrophyte species richness with only three species. The dominant species at this site were Sporobolus virginicus and Chenopodium album L. which are highly salt tolerant species. Catalina Bay had the highest species richness (18 to 27); as a result of freshwater input via groundwater seepage from the sand dune aquifers on the Eastern Shores. Along the Eastern Shores, vegetation was dominated by species of Cyperaceae, Juncaceae and Juncaginaceae. Fluctuations in groundwater depth were observed at all sites, Listers Point groundwater depth in February 2006 was 80 cm and the ground water level was not reached during the May 2010 field trip. During the May 2010 field trip, the water column salinity of the St Lucia system was highly variable, Makakatana had the lowest water column salinity of 7.1 ppt, 42.1 ppt at Catalina Bay, 44 ppt at Charters Creek and Listers Point had the highest water column salinity of 95 ppt. An assessment of the changes in macrophyte cover along the transects showed that cover fluctuated in response to rainfall, water level and drought. At Listers Point, there was a continuous decline in the abundance of Sporobolus virginicus over time which was sparsely distributed in the first 40 m of the transect. Sarcocornia natalensis, a succulent and obligate halophyte, was recorded, in areas with high sediment conductivity. In May 2010, bare ground increased to an average percentage cover of 96.5% and was covered with dead organic matter and a salt crust at Listers Point. At Makakatana, there was a significant decrease in bare ground from July 2005 to May 2010 (H = 24.58, N = 197, p<0.001) as bare areas were colonized by salt marsh. Multivariate analysis showed that the abundance of Sporobolus virginicus was positively influenced by sediment moisture content and Paspalum vaginatum abundance was strongly influenced by the water column salinity. At Catalina Bay, low sediment conductivity at the groundwater seepage area resulted in terrestrial vegetation encroaching on estuarine vegetation. Sarcocornia natalensis became more abundant towards the water column. During the period of study, species richness at St Lucia ranged from 2 (Listers Point, May 2010) to 27 (Catalina Bay, February 2006). Salinity and water level fluctuation have a significant impact on the distribution of macrophytes at St Lucia during the drought. In saline areas salt marsh plants have colonized exposed shorelines and along the Eastern Shores groundwater seepage has increased macrophyte species richness. Low water levels have resulted in the exposure and desiccation of submerged macrophytes, which are replaced by macroalgae.
- Full Text:
- Date Issued: 2012