Changing sediment yield and sediment dynamics in the Karoo uplands, South Africa : post-European impacts
- Foster, I D L, Rowntree, Kate M, Boardman, J, Mighall, T M
- Authors: Foster, I D L , Rowntree, Kate M , Boardman, J , Mighall, T M
- Date: 2012
- Language: English
- Type: Article
- Identifier: vital:6684 , http://hdl.handle.net/10962/d1006683
- Description: We provide an overview of published results and a significant body of new data from an ongoing research programme designed to reconstruct sediment yields and sources in small (<60 km2) catchments in the Eastern Cape, South Africa over the last 150 years. Our analysis of four catchments has determined that sediment yield increased significantly in the latter half of the 20th Century but that the exact timing of these increases was different in each of the four catchments. In two high altitude locations, sediment yield increases were not associated with a significant change in sediment source, although in one case areas of former cultivation appear to have made a slightly greater contribution since the 1960s. In a third catchment, increases in sediment yield appear to have been driven by the development of badlands and by an increase in connectivity between the badlands and the main channel network in the 1960s. In the fourth catchment, increased connectivity between the main catchment and dam occurred as a result of the construction of a causeway to carry a main road and by the construction of culverts beneath the road. Occasional changes in sediment source have also been identified in the sedimentary record but these were not linked directly to road construction. Research to date shows the complexity of sediment delivery in these semi-arid catchment systems and emphasises the need to combine sediment yield with source ascription in order to better understand the dynamics of these systems.
- Full Text:
- Authors: Foster, I D L , Rowntree, Kate M , Boardman, J , Mighall, T M
- Date: 2012
- Language: English
- Type: Article
- Identifier: vital:6684 , http://hdl.handle.net/10962/d1006683
- Description: We provide an overview of published results and a significant body of new data from an ongoing research programme designed to reconstruct sediment yields and sources in small (<60 km2) catchments in the Eastern Cape, South Africa over the last 150 years. Our analysis of four catchments has determined that sediment yield increased significantly in the latter half of the 20th Century but that the exact timing of these increases was different in each of the four catchments. In two high altitude locations, sediment yield increases were not associated with a significant change in sediment source, although in one case areas of former cultivation appear to have made a slightly greater contribution since the 1960s. In a third catchment, increases in sediment yield appear to have been driven by the development of badlands and by an increase in connectivity between the badlands and the main channel network in the 1960s. In the fourth catchment, increased connectivity between the main catchment and dam occurred as a result of the construction of a causeway to carry a main road and by the construction of culverts beneath the road. Occasional changes in sediment source have also been identified in the sedimentary record but these were not linked directly to road construction. Research to date shows the complexity of sediment delivery in these semi-arid catchment systems and emphasises the need to combine sediment yield with source ascription in order to better understand the dynamics of these systems.
- Full Text:
Characterization of 2,(3)-tetra-(4-oxo-benzamide) phthalocyaninato cobalt (II)—single walled carbon nanotube conjugate platforms and their use in electrocatalysis of amitrole
- Mugadza, Tawanda, Arslanoğlu, Yasin, Nyokong, Tebello
- Authors: Mugadza, Tawanda , Arslanoğlu, Yasin , Nyokong, Tebello
- Date: 2012
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/244382 , vital:51252 , xlink:href="https://doi.org/10.1016/j.electacta.2012.02.041"
- Description: In this paper we report on the use of carboxylic acid functionalized single walled carbon nanotubes (SWCNT) in the synthesis of 2,(3)-tetra-(4-oxo-benzamide)phthalocyaninato cobalt (II)–single walled carbon nanotube conjugates (CoTOBPc–SWCNT), their characterization and application in the electrocatalytic oxidation of amitrole. Cyclic voltammetry, chronoamperometry and electrochemical impedance spectroscopy were used for the detection of amitrole on the modified glassy carbon electrode. The catalytic rate constant was 1.6 × 103 M−1 s−1 and the apparent electron rate transfer constant was 1.5 × 10−5 cm s−1. The linear dynamic range was 1.0 × 10−6–3.0 × 10−5 M, with a sensitivity of ∼1.13 A mol−1 L cm−2.
- Full Text:
- Authors: Mugadza, Tawanda , Arslanoğlu, Yasin , Nyokong, Tebello
- Date: 2012
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/244382 , vital:51252 , xlink:href="https://doi.org/10.1016/j.electacta.2012.02.041"
- Description: In this paper we report on the use of carboxylic acid functionalized single walled carbon nanotubes (SWCNT) in the synthesis of 2,(3)-tetra-(4-oxo-benzamide)phthalocyaninato cobalt (II)–single walled carbon nanotube conjugates (CoTOBPc–SWCNT), their characterization and application in the electrocatalytic oxidation of amitrole. Cyclic voltammetry, chronoamperometry and electrochemical impedance spectroscopy were used for the detection of amitrole on the modified glassy carbon electrode. The catalytic rate constant was 1.6 × 103 M−1 s−1 and the apparent electron rate transfer constant was 1.5 × 10−5 cm s−1. The linear dynamic range was 1.0 × 10−6–3.0 × 10−5 M, with a sensitivity of ∼1.13 A mol−1 L cm−2.
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Chief executive officer compensation and the effect on company performance in a South African context
- Authors: Bradley, Samuel
- Date: 2012
- Subjects: Chief executive officers -- Salaries, etc. -- South Africa , Compensation management -- South Africa , Wage surveys -- South Africa , Organizational effectiveness -- Evaluation
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:883 , http://hdl.handle.net/10962/d1001637 , Chief executive officers -- Salaries, etc. -- South Africa , Compensation management -- South Africa , Wage surveys -- South Africa , Organizational effectiveness -- Evaluation
- Description: The goal of this research was to determine, in a South African context, whether there is any correlation between chief executive officer compensation and the performance of the company. For the purposes of the research , the compensation of chief executive officers was broken down into three components: salary, bonus and "other" remuneration, while company performance was measured on return on equity, return on assets and earnings per share figures. Studies on this topic have been carried out in other countries, most notably in the United States of America and the United Kingdom. It appears that no research of a similar nature has been carried out in South Africa. Data in respect of the forty largest listed companies in South Africa were collected over a period of five years. The econometric models used for the research were based on models identified in the literature study. The data were then analysed for evidence of a correlation between chief executive officer compensation and the performance of the company. The results of this study indicate that there is no linear relationship between chief executive officer compensation and company performance variables. The econometric models did, however, show correlations between certain variables, taking into account the other predictor variables in the model. Evidence of correlations between age and experience and compensation was also found , which may present potential avenues of research to scholars in the future.
- Full Text:
- Authors: Bradley, Samuel
- Date: 2012
- Subjects: Chief executive officers -- Salaries, etc. -- South Africa , Compensation management -- South Africa , Wage surveys -- South Africa , Organizational effectiveness -- Evaluation
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:883 , http://hdl.handle.net/10962/d1001637 , Chief executive officers -- Salaries, etc. -- South Africa , Compensation management -- South Africa , Wage surveys -- South Africa , Organizational effectiveness -- Evaluation
- Description: The goal of this research was to determine, in a South African context, whether there is any correlation between chief executive officer compensation and the performance of the company. For the purposes of the research , the compensation of chief executive officers was broken down into three components: salary, bonus and "other" remuneration, while company performance was measured on return on equity, return on assets and earnings per share figures. Studies on this topic have been carried out in other countries, most notably in the United States of America and the United Kingdom. It appears that no research of a similar nature has been carried out in South Africa. Data in respect of the forty largest listed companies in South Africa were collected over a period of five years. The econometric models used for the research were based on models identified in the literature study. The data were then analysed for evidence of a correlation between chief executive officer compensation and the performance of the company. The results of this study indicate that there is no linear relationship between chief executive officer compensation and company performance variables. The econometric models did, however, show correlations between certain variables, taking into account the other predictor variables in the model. Evidence of correlations between age and experience and compensation was also found , which may present potential avenues of research to scholars in the future.
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Chieftainship succession and gender equality in Lesotho: negotiating the right to equality in a jungle of pluralism
- Authors: Juma, Laurence
- Date: 2012
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/127067 , vital:35951 , https://heinonline.org/HOL/Page?handle=hein.journals/tjwl22amp;div=11amp;g_sent=1amp;casa_token=amp;collection=journals
- Description: Women constitute about 51% of Lesotho's population 1 and enjoy a higher literacy rate than men. 2 They are also the backbone of a society that for several hundreds of years provided male labor to South Africa's farms and gold mines.3 However, Basotho women are generally excluded from mainstream politics and are discriminated against in almost all spheres of socioeconomic life. This exclusion, marginalization, and discrimination have been largely blamed on patriarchy and entrenched traditional norms, both of which are sustained by a plural legal system that has seemingly remained insular to developments around the globe. 4
- Full Text:
- Authors: Juma, Laurence
- Date: 2012
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/127067 , vital:35951 , https://heinonline.org/HOL/Page?handle=hein.journals/tjwl22amp;div=11amp;g_sent=1amp;casa_token=amp;collection=journals
- Description: Women constitute about 51% of Lesotho's population 1 and enjoy a higher literacy rate than men. 2 They are also the backbone of a society that for several hundreds of years provided male labor to South Africa's farms and gold mines.3 However, Basotho women are generally excluded from mainstream politics and are discriminated against in almost all spheres of socioeconomic life. This exclusion, marginalization, and discrimination have been largely blamed on patriarchy and entrenched traditional norms, both of which are sustained by a plural legal system that has seemingly remained insular to developments around the globe. 4
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China in South Africa: a long affair: Africa rising
- Authors: Wasserman, Herman
- Date: 2012
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/454594 , vital:75358 , https://hdl.handle.net/10520/EJC134108
- Description: Official relations between Africa and China in contemporary times can be seen to have started in 1955 with the first Asian-African Conference in Bandung, Indonesia, aimed at promoting economic and cultural co-operation. The development of China-Africa relations gained impetus when it became clear in the 1990s that to maintain the "roaring pace" of its economic growth as a result of economic reforms, China would need to look for new sources of energy and natural resources - which it found in Africa.
- Full Text:
- Authors: Wasserman, Herman
- Date: 2012
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/454594 , vital:75358 , https://hdl.handle.net/10520/EJC134108
- Description: Official relations between Africa and China in contemporary times can be seen to have started in 1955 with the first Asian-African Conference in Bandung, Indonesia, aimed at promoting economic and cultural co-operation. The development of China-Africa relations gained impetus when it became clear in the 1990s that to maintain the "roaring pace" of its economic growth as a result of economic reforms, China would need to look for new sources of energy and natural resources - which it found in Africa.
- Full Text:
China-Africa relations: research approaches
- Authors: Simbao, Ruth K
- Date: 2012
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/147503 , vital:38644 , https://doi.org/10.1162/afar.2012.45.2.1
- Description: About to board a plane in Johannesburg, I handed my temporary boarding pass to the flight attendant who exclaimed,“Simbao, you have a fong kong boarding pass!” Fong kong is a slang term used in South Africa meaning fake, cheap, or low quality and is often associated with Chinese imports. In this case, the term was used to refer to a temporary pass issued earlier on my journey that needed to be replaced with a new boarding pass in Johannesburg.
- Full Text:
- Authors: Simbao, Ruth K
- Date: 2012
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/147503 , vital:38644 , https://doi.org/10.1162/afar.2012.45.2.1
- Description: About to board a plane in Johannesburg, I handed my temporary boarding pass to the flight attendant who exclaimed,“Simbao, you have a fong kong boarding pass!” Fong kong is a slang term used in South Africa meaning fake, cheap, or low quality and is often associated with Chinese imports. In this case, the term was used to refer to a temporary pass issued earlier on my journey that needed to be replaced with a new boarding pass in Johannesburg.
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Civil society and state-centred struggles
- Authors: Helliker, Kirk D
- Date: 2012
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/71231 , vital:29821 , https://doi.org/10.1080/02589001.2012.641723
- Description: This article is about civil society and state-centred struggles in contemporary Zimbabwe. I first identify and outline three current understandings of civil society. Two understandings (one Liberal, one Radical) are state-centric and exist firmly within the logic of state discourses and state politics. A third understanding, also Radical, is society-centric and speaks about politics existing at a distance from the state and possibly beyond the boundaries of civil society. This civil society-state discussion frames the second section of the article, which looks specifically at Zimbabwe. It details civil society as contested terrain (from the late 1990s onwards) within the context of a scholarly debate about agrarian transformation and political change. This debate, which reproduces (in theoretical garb) the key political society (or party) fault-lines within Zimbabwean society, has taken place primarily within the restricted confines of state-centred discourses.
- Full Text:
- Authors: Helliker, Kirk D
- Date: 2012
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/71231 , vital:29821 , https://doi.org/10.1080/02589001.2012.641723
- Description: This article is about civil society and state-centred struggles in contemporary Zimbabwe. I first identify and outline three current understandings of civil society. Two understandings (one Liberal, one Radical) are state-centric and exist firmly within the logic of state discourses and state politics. A third understanding, also Radical, is society-centric and speaks about politics existing at a distance from the state and possibly beyond the boundaries of civil society. This civil society-state discussion frames the second section of the article, which looks specifically at Zimbabwe. It details civil society as contested terrain (from the late 1990s onwards) within the context of a scholarly debate about agrarian transformation and political change. This debate, which reproduces (in theoretical garb) the key political society (or party) fault-lines within Zimbabwean society, has taken place primarily within the restricted confines of state-centred discourses.
- Full Text:
Classifying network attack scenarios using an ontology
- Van Heerden, Renier, Irwin, Barry V W, Burke, I D
- Authors: Van Heerden, Renier , Irwin, Barry V W , Burke, I D
- Date: 2012
- Language: English
- Type: Conference paper
- Identifier: vital:6606 , http://hdl.handle.net/10962/d1009326
- Description: This paper presents a methodology using network attack ontology to classify computer-based attacks. Computer network attacks differ in motivation, execution and end result. Because attacks are diverse, no standard classification exists. If an attack could be classified, it could be mitigated accordingly. A taxonomy of computer network attacks forms the basis of the ontology. Most published taxonomies present an attack from either the attacker's or defender's point of view. This taxonomy presents both views. The main taxonomy classes are: Actor, Actor Location, Aggressor, Attack Goal, Attack Mechanism, Attack Scenario, Automation Level, Effects, Motivation, Phase, Scope and Target. The "Actor" class is the entity executing the attack. The "Actor Location" class is the Actor‟s country of origin. The "Aggressor" class is the group instigating an attack. The "Attack Goal" class specifies the attacker‟s goal. The "Attack Mechanism" class defines the attack methodology. The "Automation Level" class indicates the level of human interaction. The "Effects" class describes the consequences of an attack. The "Motivation" class specifies incentives for an attack. The "Scope" class describes the size and utility of the target. The "Target" class is the physical device or entity targeted by an attack. The "Vulnerability" class describes a target vulnerability used by the attacker. The "Phase" class represents an attack model that subdivides an attack into different phases. The ontology was developed using an "Attack Scenario" class, which draws from other classes and can be used to characterize and classify computer network attacks. An "Attack Scenario" consists of phases, has a scope and is attributed to an actor and aggressor which have a goal. The "Attack Scenario" thus represents different classes of attacks. High profile computer network attacks such as Stuxnet and the Estonia attacks can now be been classified through the “Attack Scenario” class.
- Full Text:
- Authors: Van Heerden, Renier , Irwin, Barry V W , Burke, I D
- Date: 2012
- Language: English
- Type: Conference paper
- Identifier: vital:6606 , http://hdl.handle.net/10962/d1009326
- Description: This paper presents a methodology using network attack ontology to classify computer-based attacks. Computer network attacks differ in motivation, execution and end result. Because attacks are diverse, no standard classification exists. If an attack could be classified, it could be mitigated accordingly. A taxonomy of computer network attacks forms the basis of the ontology. Most published taxonomies present an attack from either the attacker's or defender's point of view. This taxonomy presents both views. The main taxonomy classes are: Actor, Actor Location, Aggressor, Attack Goal, Attack Mechanism, Attack Scenario, Automation Level, Effects, Motivation, Phase, Scope and Target. The "Actor" class is the entity executing the attack. The "Actor Location" class is the Actor‟s country of origin. The "Aggressor" class is the group instigating an attack. The "Attack Goal" class specifies the attacker‟s goal. The "Attack Mechanism" class defines the attack methodology. The "Automation Level" class indicates the level of human interaction. The "Effects" class describes the consequences of an attack. The "Motivation" class specifies incentives for an attack. The "Scope" class describes the size and utility of the target. The "Target" class is the physical device or entity targeted by an attack. The "Vulnerability" class describes a target vulnerability used by the attacker. The "Phase" class represents an attack model that subdivides an attack into different phases. The ontology was developed using an "Attack Scenario" class, which draws from other classes and can be used to characterize and classify computer network attacks. An "Attack Scenario" consists of phases, has a scope and is attributed to an actor and aggressor which have a goal. The "Attack Scenario" thus represents different classes of attacks. High profile computer network attacks such as Stuxnet and the Estonia attacks can now be been classified through the “Attack Scenario” class.
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COIN : a customisable, incentive driven video on demand framework for low-cost IPTV services
- Authors: Musvibe, Ray
- Date: 2012 , 2012-03-02
- Subjects: Internet television , Digital television , Television broadcasting -- Technological innovations , Multicasting (Computer networks) , Video dial tone , Open source software , Telecommunication , Capital investments
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4654 , http://hdl.handle.net/10962/d1006650 , Internet television , Digital television , Television broadcasting -- Technological innovations , Multicasting (Computer networks) , Video dial tone , Open source software , Telecommunication , Capital investments
- Description: There has been a significant rise in the provision of television and video services over IP (IPTV) in recent years. Increasing network capacity and falling bandwidth costs have made it both technically and economically feasible for service providers to deliver IPTV services. Several telecommunications (telco) operators worldwide are rolling out IPTV solutions and view IPTV as a major service differentiator and alternative revenue source. The main challenge that IPTV providers currently face, however, is the increasingly congested television service provider market, which also includes Internet Television. IPTV solutions therefore need strong service differentiators to succeed. IPTV solutions can doubtlessly sell much faster if they are more affordable or low-cost. Advertising has already been used in many service sectors to help lower service costs, including traditional broadcast television. This thesis therefore explores the role that advertising can play in helping to lower the cost of IPTV services and to incentivise IPTV billing. Another approach that IPTV providers can use to help sell their product is by addressing the growing need for control by today's multimedia users. This thesis will therefore explore the varied approaches that can be used to achieve viewer focused IPTV implementations. To further lower the cost of IPTV services, telcos can also turn to low-cost, open source platforms for service delivery. The adoption of low-cost infrastructure by telcos can lead to reduced Capital Expenditure (CAPEX), which in turn can lead to lower service fees, and ultimately to higher subscriptions and revenue. Therefore, in this thesis, the author proposes a CustOmisable, INcentive (COIN) driven Video on Demand (VoD) framework to be developed and deployed using the Mobicents Communication Platform, an open source service creation and execution platform. The COIN framework aims to provide a viewer focused, economically competitive service that combines the potential cost savings of using free and open source software (FOSS), with an innovative, incentive-driven billing approach. This project will also aim to evaluate whether the Mobicents Platform is a suitable service creation and execution platform for the proposed framework. Additionally, the proposed implementation aims to be interoperable with other IPTV implementations, hence shall follow current IPTV standardisation architectures and trends. The service testbed and its implementation are described in detail and only free and open source software is used; this is to enable its easy duplication and extension for future research. , TeX output 2012.03.02:1241 , Adobe Acrobat 9.2 Paper Capture Plug-in
- Full Text:
- Authors: Musvibe, Ray
- Date: 2012 , 2012-03-02
- Subjects: Internet television , Digital television , Television broadcasting -- Technological innovations , Multicasting (Computer networks) , Video dial tone , Open source software , Telecommunication , Capital investments
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4654 , http://hdl.handle.net/10962/d1006650 , Internet television , Digital television , Television broadcasting -- Technological innovations , Multicasting (Computer networks) , Video dial tone , Open source software , Telecommunication , Capital investments
- Description: There has been a significant rise in the provision of television and video services over IP (IPTV) in recent years. Increasing network capacity and falling bandwidth costs have made it both technically and economically feasible for service providers to deliver IPTV services. Several telecommunications (telco) operators worldwide are rolling out IPTV solutions and view IPTV as a major service differentiator and alternative revenue source. The main challenge that IPTV providers currently face, however, is the increasingly congested television service provider market, which also includes Internet Television. IPTV solutions therefore need strong service differentiators to succeed. IPTV solutions can doubtlessly sell much faster if they are more affordable or low-cost. Advertising has already been used in many service sectors to help lower service costs, including traditional broadcast television. This thesis therefore explores the role that advertising can play in helping to lower the cost of IPTV services and to incentivise IPTV billing. Another approach that IPTV providers can use to help sell their product is by addressing the growing need for control by today's multimedia users. This thesis will therefore explore the varied approaches that can be used to achieve viewer focused IPTV implementations. To further lower the cost of IPTV services, telcos can also turn to low-cost, open source platforms for service delivery. The adoption of low-cost infrastructure by telcos can lead to reduced Capital Expenditure (CAPEX), which in turn can lead to lower service fees, and ultimately to higher subscriptions and revenue. Therefore, in this thesis, the author proposes a CustOmisable, INcentive (COIN) driven Video on Demand (VoD) framework to be developed and deployed using the Mobicents Communication Platform, an open source service creation and execution platform. The COIN framework aims to provide a viewer focused, economically competitive service that combines the potential cost savings of using free and open source software (FOSS), with an innovative, incentive-driven billing approach. This project will also aim to evaluate whether the Mobicents Platform is a suitable service creation and execution platform for the proposed framework. Additionally, the proposed implementation aims to be interoperable with other IPTV implementations, hence shall follow current IPTV standardisation architectures and trends. The service testbed and its implementation are described in detail and only free and open source software is used; this is to enable its easy duplication and extension for future research. , TeX output 2012.03.02:1241 , Adobe Acrobat 9.2 Paper Capture Plug-in
- Full Text:
Communication at the health care coalface: lessons from selected clinics in Port Elizabeth
- Authors: Mbengo, Nomatshawe
- Date: 2012
- Subjects: Communication in medicine -- Research -- South Africa Community health services -- South Africa -- Eastern Cape Social medicine -- Research -- South Africa Medical care -- Research -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3591 , http://hdl.handle.net/10962/d1002166
- Description: This thesis analyses the state of health care in South Africa with particular reference to a clinic and the Provincial Hospital in Port Elizabeth, Eastern Cape. The complexities of health care provision in a diverse sociolinguistic environment where certain languages are emphasized over others, forms the cornerstone of the research. The research focuses on health care in a complex multi-cultural environment. The goal of the research is to present a coherent and robust translation framework for the development of suitable materials to enhance communication across language and cultural barriers in the health care sector. A model (based on research completed in the USA) is presented as a possible alternative in the final chapter of the thesis.
- Full Text:
- Authors: Mbengo, Nomatshawe
- Date: 2012
- Subjects: Communication in medicine -- Research -- South Africa Community health services -- South Africa -- Eastern Cape Social medicine -- Research -- South Africa Medical care -- Research -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3591 , http://hdl.handle.net/10962/d1002166
- Description: This thesis analyses the state of health care in South Africa with particular reference to a clinic and the Provincial Hospital in Port Elizabeth, Eastern Cape. The complexities of health care provision in a diverse sociolinguistic environment where certain languages are emphasized over others, forms the cornerstone of the research. The research focuses on health care in a complex multi-cultural environment. The goal of the research is to present a coherent and robust translation framework for the development of suitable materials to enhance communication across language and cultural barriers in the health care sector. A model (based on research completed in the USA) is presented as a possible alternative in the final chapter of the thesis.
- Full Text:
Comparative biogeography and ecology of freshwater fishes in the Breede and associated river systems, South Africa
- Authors: Chakona, Albert
- Date: 2012
- Subjects: Freshwater fishes -- South Africa -- Breede River , Freshwater fishes -- South Africa -- Geographical distribution , Freshwater fishes -- Ecology , Feshwater fishes -- Genetics
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5372 , http://hdl.handle.net/10962/d1015694
- Description: Distribution patterns and levels of genetic diversity in extant taxa are a product of complex palaeogeographic processes and climatic oscillations as well as the species’ intrinsic ecological adaptations. The Cape Floristic Region of South Africa presents a unique system for studying the processes that promote species diversification and distribution patterns. This region has a high degree of endemism of both terrestrial and aquatic biota and is clearly isolated from neighbouring areas by the Cape Fold Mountains and the Great Escarpment. The objective of this study was to firstly examine the ecology of freshwater fishes belonging to the genera Galaxias, Pseudobarbus and Sandelia in the south-western CFR. This was followed by an assessment of the genetic diversity of these taxa. Unique lineages were identified and their distribution was mapped. The work aimed to explore the role of the region’s complex palaeogeographic and climatic history as well as the role of the species’ ecological adaptations in driving lineage diversification and shaping contemporary distribution patterns. The four main components of the study can be summarised as follows: 1. Habitat associations of three widely distributed lineages of Galaxias zebratus Pseudobarbus burchelli and Sandelia capensis were evaluated at multiple localities in minimally disturbed mountain tributaries of the Breede, Duiwenhoks and Goukou River systems. The lineages have distinct habitat associations which were related to differences in their morphological traits. The slender-bodied Galaxias ‘nebula’ and the fusiform-shaped Pseudobarbus ‘Breede’ are capable of exploiting upper reaches with faster water velocity. By contrast, the laterally compressed Sandelia ‘eastern’ is restricted to lower reaches, making this lineage more susceptible to a wide array of impacts. 2. A recently discovered lineage of Galaxias zebratus, (Galaxias ‘nebula’), was found to be capable of tolerating emersion for a prolonged period of time. This is the first time that such capabilities have been documented in an African galaxiid. These adaptations have implications for the interpretation of Galaxias ‘nebula’s wide distribution range. 3. The phylogeography of Galaxias ‘nebula’ across its entire distribution range was investigated using two mitochondrial genes (cytochrome c oxidase subunit I (COI) and cytochrome b (cyt b)). This lineage has a complex evolutionary history that was influenced by both intrinsic and extrinsic factors. Rare events such as episodic drainage connections during Pleistocene and Holocene pluvial periods, possibly augmented by river confluences during periods of lower sea-levels and river capture events seem to be the most credible explanation for the extensive contemporary distribution and the relatively shallow genetic divergence between different river systems. 4. Mitochondrial cyt b sequences were used (i) to assess genetic diversity in G. zebratus, P. burchelli and S. capensis from the south-western CFR and (ii) to determine the roles of intrinsic ecological adaptations and extrinsic landscape and climatic changes in promoting genetic diversification and shaping present day distribution patterns of lineages in the three taxa. Marine incursions during periods of major sea-level transgressions are proposed to have isolated populations in upland refugia, thereby driving allopatric divergence in these species. Subsequent connections of rivers during wetter periods and lower sea-levels are proposed to have facilitated post-speciation dispersal of lineages to attain present day distribution patterns. While detailed morphological studies and further genetic analysis are needed to substantiate the taxonomic status of the newly discovered lineages of Galaxias zebratus, Pseudobarbus burchelli and Sandelia capensis, results of the present study indicate that the south-western CFR represents a previously unrecognised centre of freshwater fish diversity and microendemism in the broader Cape Floristic Region. Accurate identification of lineages and comprehensive mapping of their distribution is a fundamental pre-requisite for ecological studies, assessing conservation status and implementation of appropriate conservation measures.
- Full Text:
- Authors: Chakona, Albert
- Date: 2012
- Subjects: Freshwater fishes -- South Africa -- Breede River , Freshwater fishes -- South Africa -- Geographical distribution , Freshwater fishes -- Ecology , Feshwater fishes -- Genetics
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5372 , http://hdl.handle.net/10962/d1015694
- Description: Distribution patterns and levels of genetic diversity in extant taxa are a product of complex palaeogeographic processes and climatic oscillations as well as the species’ intrinsic ecological adaptations. The Cape Floristic Region of South Africa presents a unique system for studying the processes that promote species diversification and distribution patterns. This region has a high degree of endemism of both terrestrial and aquatic biota and is clearly isolated from neighbouring areas by the Cape Fold Mountains and the Great Escarpment. The objective of this study was to firstly examine the ecology of freshwater fishes belonging to the genera Galaxias, Pseudobarbus and Sandelia in the south-western CFR. This was followed by an assessment of the genetic diversity of these taxa. Unique lineages were identified and their distribution was mapped. The work aimed to explore the role of the region’s complex palaeogeographic and climatic history as well as the role of the species’ ecological adaptations in driving lineage diversification and shaping contemporary distribution patterns. The four main components of the study can be summarised as follows: 1. Habitat associations of three widely distributed lineages of Galaxias zebratus Pseudobarbus burchelli and Sandelia capensis were evaluated at multiple localities in minimally disturbed mountain tributaries of the Breede, Duiwenhoks and Goukou River systems. The lineages have distinct habitat associations which were related to differences in their morphological traits. The slender-bodied Galaxias ‘nebula’ and the fusiform-shaped Pseudobarbus ‘Breede’ are capable of exploiting upper reaches with faster water velocity. By contrast, the laterally compressed Sandelia ‘eastern’ is restricted to lower reaches, making this lineage more susceptible to a wide array of impacts. 2. A recently discovered lineage of Galaxias zebratus, (Galaxias ‘nebula’), was found to be capable of tolerating emersion for a prolonged period of time. This is the first time that such capabilities have been documented in an African galaxiid. These adaptations have implications for the interpretation of Galaxias ‘nebula’s wide distribution range. 3. The phylogeography of Galaxias ‘nebula’ across its entire distribution range was investigated using two mitochondrial genes (cytochrome c oxidase subunit I (COI) and cytochrome b (cyt b)). This lineage has a complex evolutionary history that was influenced by both intrinsic and extrinsic factors. Rare events such as episodic drainage connections during Pleistocene and Holocene pluvial periods, possibly augmented by river confluences during periods of lower sea-levels and river capture events seem to be the most credible explanation for the extensive contemporary distribution and the relatively shallow genetic divergence between different river systems. 4. Mitochondrial cyt b sequences were used (i) to assess genetic diversity in G. zebratus, P. burchelli and S. capensis from the south-western CFR and (ii) to determine the roles of intrinsic ecological adaptations and extrinsic landscape and climatic changes in promoting genetic diversification and shaping present day distribution patterns of lineages in the three taxa. Marine incursions during periods of major sea-level transgressions are proposed to have isolated populations in upland refugia, thereby driving allopatric divergence in these species. Subsequent connections of rivers during wetter periods and lower sea-levels are proposed to have facilitated post-speciation dispersal of lineages to attain present day distribution patterns. While detailed morphological studies and further genetic analysis are needed to substantiate the taxonomic status of the newly discovered lineages of Galaxias zebratus, Pseudobarbus burchelli and Sandelia capensis, results of the present study indicate that the south-western CFR represents a previously unrecognised centre of freshwater fish diversity and microendemism in the broader Cape Floristic Region. Accurate identification of lineages and comprehensive mapping of their distribution is a fundamental pre-requisite for ecological studies, assessing conservation status and implementation of appropriate conservation measures.
- Full Text:
Comparison of carbon screen-printed and disk electrodes in the detection of antioxidants using CoPc derivatives
- Matemadombo, Fungisai, Apetrei, Constantin, Nyokong, Tebello, Rodríguez-Méndez, María Luz, de Saja, José Antonio
- Authors: Matemadombo, Fungisai , Apetrei, Constantin , Nyokong, Tebello , Rodríguez-Méndez, María Luz , de Saja, José Antonio
- Date: 2012
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/244371 , vital:51251 , xlink:href="https://doi.org/10.1016/j.snb.2012.02.088"
- Description: Cobalt phthalocyanine (CoPc) and cobalt phthalocyanine carboxylic derivatives (CoTCPc and CoOCPc) have been used as electrocatalysts for the detection of the antioxidants vanillic acid, caffeic acid, pyrogallol, and ascorbic acid on screen-printed carbon and disk electrode surfaces. The cobalt phthalocyanines were used to detect vanillic acid (with limit of detection ranging from 1.15 μM to 2.42 μM at potentials of 0.55–0.88 V vs. Ag|AgCl), caffeic acid (with limit of detection ranging from 1.17 μM to 2.20 μM at potentials of 0.30–0.81 V vs. Ag|AgCl), pyrogallol (with limit of detection ranging from 1.16 μM to 3.63 μM at potentials of 0.52–0.63 V vs. Ag|AgCl), and ascorbic acid (with limit of detection ranging from 1.16 μM to 1.58 μM at potentials of 0.34–0.46 V vs. Ag|AgCl). The kinetic studies also demonstrate diffusion-controlled processes at the electrode surface. The SPCE electrodes have better detection properties towards vanillic acid, caffeic acid, pyrogallol while the disk electrodes had better ascorbic acid detection properties as proven by kinetic studies. Both types CoPc-influenced electrodes show 100% discrimination of the antioxidants.
- Full Text:
- Authors: Matemadombo, Fungisai , Apetrei, Constantin , Nyokong, Tebello , Rodríguez-Méndez, María Luz , de Saja, José Antonio
- Date: 2012
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/244371 , vital:51251 , xlink:href="https://doi.org/10.1016/j.snb.2012.02.088"
- Description: Cobalt phthalocyanine (CoPc) and cobalt phthalocyanine carboxylic derivatives (CoTCPc and CoOCPc) have been used as electrocatalysts for the detection of the antioxidants vanillic acid, caffeic acid, pyrogallol, and ascorbic acid on screen-printed carbon and disk electrode surfaces. The cobalt phthalocyanines were used to detect vanillic acid (with limit of detection ranging from 1.15 μM to 2.42 μM at potentials of 0.55–0.88 V vs. Ag|AgCl), caffeic acid (with limit of detection ranging from 1.17 μM to 2.20 μM at potentials of 0.30–0.81 V vs. Ag|AgCl), pyrogallol (with limit of detection ranging from 1.16 μM to 3.63 μM at potentials of 0.52–0.63 V vs. Ag|AgCl), and ascorbic acid (with limit of detection ranging from 1.16 μM to 1.58 μM at potentials of 0.34–0.46 V vs. Ag|AgCl). The kinetic studies also demonstrate diffusion-controlled processes at the electrode surface. The SPCE electrodes have better detection properties towards vanillic acid, caffeic acid, pyrogallol while the disk electrodes had better ascorbic acid detection properties as proven by kinetic studies. Both types CoPc-influenced electrodes show 100% discrimination of the antioxidants.
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Competence development in marine protected area professionals: a case study of the South African Marine Protected Area Management Training Course (SAMPATC)
- Authors: Lewis, Sebastian Giulio
- Date: 2012
- Subjects: Core competencies Employees -- Training of Marine ecosystem management
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1456 , http://hdl.handle.net/10962/d1003337
- Description: This study reviews a training programme on Marine Protected Area (MPA) management. It notes that although MPAs are well promulgated under legislation, reports have found that there are still key challenges facing the management of these areas. The research examines how the course was developed following the Lemm and Attwood (2003) report and designed to develop competences for effective MPA management. The aim is to identify how a MPA management training course produced competences apposite to the workplace settings of the participants. An interpretive case study method was used, in two phases. The first phase explored salient issues in MPA management in South Africa through analysis of the two key ‘state of MPA management’ reports and interviews with MPA professionals. The second was an analysis of the South African Marine Protected Area Management Training Course. This involved interviews with course designers, a review of the course materials, interviews with past course participants, and an analysis of course evaluations. Evidence emerged that supported the following findings: Challenges and problems facing MPA management still exist. Competence in key areas of MPA management was addressed in an effective work-integrated approach. Social learning was a key process in the development of these competences. The competences articulate well with the workplace of participants. Gaps exist between some of the management issues and the competences developed by the course, and some aspects of the course design are ineffective. From these findings it is concluded that: The course took up the majority of issues in MPA management through the development of key competences. The course design facilitated the development of these competences. The competences developed through the course are relevant to the workplace of MPA professionals. The research found that the course adequately addresses issues in MPA management through the development of competences. Some recommendations for improvements are made.
- Full Text:
- Authors: Lewis, Sebastian Giulio
- Date: 2012
- Subjects: Core competencies Employees -- Training of Marine ecosystem management
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1456 , http://hdl.handle.net/10962/d1003337
- Description: This study reviews a training programme on Marine Protected Area (MPA) management. It notes that although MPAs are well promulgated under legislation, reports have found that there are still key challenges facing the management of these areas. The research examines how the course was developed following the Lemm and Attwood (2003) report and designed to develop competences for effective MPA management. The aim is to identify how a MPA management training course produced competences apposite to the workplace settings of the participants. An interpretive case study method was used, in two phases. The first phase explored salient issues in MPA management in South Africa through analysis of the two key ‘state of MPA management’ reports and interviews with MPA professionals. The second was an analysis of the South African Marine Protected Area Management Training Course. This involved interviews with course designers, a review of the course materials, interviews with past course participants, and an analysis of course evaluations. Evidence emerged that supported the following findings: Challenges and problems facing MPA management still exist. Competence in key areas of MPA management was addressed in an effective work-integrated approach. Social learning was a key process in the development of these competences. The competences articulate well with the workplace of participants. Gaps exist between some of the management issues and the competences developed by the course, and some aspects of the course design are ineffective. From these findings it is concluded that: The course took up the majority of issues in MPA management through the development of key competences. The course design facilitated the development of these competences. The competences developed through the course are relevant to the workplace of MPA professionals. The research found that the course adequately addresses issues in MPA management through the development of competences. Some recommendations for improvements are made.
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Comprehension and production of figurative language by Afrikaans-speaking children with and without specific language impairment
- Van der Merwe, Kristin, Adendorff, Ralph D
- Authors: Van der Merwe, Kristin , Adendorff, Ralph D
- Date: 2012
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/123442 , vital:35438 , https://doi.org/10.2989/16073614.2012.693708
- Description: This article reports on the comprehension and production of figurative language, namely idioms and similes, in first language Afrikaans-speaking (AFR) boys, ages eight to 10 years, and first language Afrikaans-speaking boys with specific language impairment (SLI), also ages eight to 10. It draws on a larger study by Van der Merwe (2007; see also Van der Merwe & Southwood, 2008). Testing of the comprehension and production abilities of the children was conducted verbally and individually and elicited their understanding of 25 idioms and 25 similes. The idioms were first presented without context; if the child gave an incorrect interpretation, the idiom was placed in context. Raw scores show that the SLI group performed marginally more poorly than the AFR group, but there was no statistically significant difference between the comprehension of idioms by the two groups. The same can be said for the number of literal interpretations provided by the groups. Placing the idioms in context was beneficial to both groups. The simile completion task required the children to provide the last word of each simile. For both groups, the similes task proved to be easier than the idioms task but there was again no statistically significant difference found between the two groups. The results seem to imply that children at this developmental phase, aged eight to 10, whether language impaired or not, have not yet fully grasped figurative language as a concept and need explicit instructions on figurative language. The article ends with a reflection on the suitability of idioms and similes as particular categories of figurative language in studies of this nature.
- Full Text:
- Authors: Van der Merwe, Kristin , Adendorff, Ralph D
- Date: 2012
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/123442 , vital:35438 , https://doi.org/10.2989/16073614.2012.693708
- Description: This article reports on the comprehension and production of figurative language, namely idioms and similes, in first language Afrikaans-speaking (AFR) boys, ages eight to 10 years, and first language Afrikaans-speaking boys with specific language impairment (SLI), also ages eight to 10. It draws on a larger study by Van der Merwe (2007; see also Van der Merwe & Southwood, 2008). Testing of the comprehension and production abilities of the children was conducted verbally and individually and elicited their understanding of 25 idioms and 25 similes. The idioms were first presented without context; if the child gave an incorrect interpretation, the idiom was placed in context. Raw scores show that the SLI group performed marginally more poorly than the AFR group, but there was no statistically significant difference between the comprehension of idioms by the two groups. The same can be said for the number of literal interpretations provided by the groups. Placing the idioms in context was beneficial to both groups. The simile completion task required the children to provide the last word of each simile. For both groups, the similes task proved to be easier than the idioms task but there was again no statistically significant difference found between the two groups. The results seem to imply that children at this developmental phase, aged eight to 10, whether language impaired or not, have not yet fully grasped figurative language as a concept and need explicit instructions on figurative language. The article ends with a reflection on the suitability of idioms and similes as particular categories of figurative language in studies of this nature.
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Computer-aided identification of coelacanths, latimeria chalumnae, using scale patterns
- Thornycroft, Rosanne E, Booth, Anthony J
- Authors: Thornycroft, Rosanne E , Booth, Anthony J
- Date: 2012
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/124013 , vital:35526 , https://doi.10.1080/17451000.2011.628679
- Description: Despite coelacanths, Latimeria chalumnae, being listed as either endangered by CITES or critically endangered by the IUCN, their population size within South Africa is unknown and still needs to be estimated. Their conservation status unfortunately excludes the use of conventional tagging to mark individual animals for a possible mark-recapture experiment. This study shows that because coelacanths have a unique spot patterning it is possible to quickly and accurately identify specific individuals photographically using computer-aided identification software. Without any manual intervention by an operator, the software accurately identified between 56 and 92% of the individuals. Indentification success increased to 100% if the operator could also manually select from other potential matching photographs. It was also shown that fish exhibiting a yaw angle not exceeding 60˚ could be accurately identified in photographs, although the percentage of fish correctly identified without operator-intervention decreased rapidly with increasing yaw angle. Computer-aided identification should therefore facilitate future coelacanth research as it is both efficient and accurate while also reducing potential stress on the animals observed.
- Full Text:
- Authors: Thornycroft, Rosanne E , Booth, Anthony J
- Date: 2012
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/124013 , vital:35526 , https://doi.10.1080/17451000.2011.628679
- Description: Despite coelacanths, Latimeria chalumnae, being listed as either endangered by CITES or critically endangered by the IUCN, their population size within South Africa is unknown and still needs to be estimated. Their conservation status unfortunately excludes the use of conventional tagging to mark individual animals for a possible mark-recapture experiment. This study shows that because coelacanths have a unique spot patterning it is possible to quickly and accurately identify specific individuals photographically using computer-aided identification software. Without any manual intervention by an operator, the software accurately identified between 56 and 92% of the individuals. Indentification success increased to 100% if the operator could also manually select from other potential matching photographs. It was also shown that fish exhibiting a yaw angle not exceeding 60˚ could be accurately identified in photographs, although the percentage of fish correctly identified without operator-intervention decreased rapidly with increasing yaw angle. Computer-aided identification should therefore facilitate future coelacanth research as it is both efficient and accurate while also reducing potential stress on the animals observed.
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Constraints to the implementation of a market development approach to the delivery of business Development Services within the Makana municipal area
- Authors: Van Heerden, Garth William
- Date: 2012
- Subjects: Makana Municipality Local government -- South Africa -- Eastern Cape Small business -- South Africa -- Eastern Cape Small business -- South Africa -- Eastern Cape -- Growth Small business -- South Africa -- Eastern Cape -- Public opinion Small business marketing -- South Africa -- Eastern Cape Economic development -- South Africa -- Eastern Cape Unemployment -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:814 , http://hdl.handle.net/10962/d1007746
- Description: South Africa's biggest challenge remains the high rate of unemployment especially among the country's youth. Small, medium and micro enterprises (SMMEs) have been shown to be instrumental in many third world economies as a sustainable means not only to address unemployment but also to contribute significantly to economic growth. Despite government's good intentions and support, the South African SMME sector is not growing as expected and this is impacting negatively on unemployment creation in the country. Good business development services (BDS) is necessary to support SMMEs and specifically the Market Development Approach to the provision of BDS, where subsidies are replaced by private payment for services. Makana municipal area provided scope for analysing the constraints to the implementation of such business development services. Analysing the scope and magnitude of the constraints in this setting would contribute to understanding the constraints also in other parts of the country and help officials in local economic development make better informed decisions regarding support to SMMEs. Authors like Rogerson (2011), UNDP (2004), Miehlbradt and McVay, (2003), the Committee of Donor Agencies for SME Development (Blue book) (2001) and Bear et al., (2001) Gibson (2001), propose that the key to sustainable BDS is the implementation of the Market Development approach which focusses on for-profit activities in the provision of BDS to SMMEs. The aim of this study was to examine perceptions of key stakeholders towards SMME support and development, to identify the constraints to the implementation of a Market Development approach to the provision of business development services to SMMEs in the Makana area and to make recommendations to the Makana LED office of possible intervention strategies to address identified constraints. Purposive sampling was used to identify key stakeholders in SMME support in the Makana area in the categories of, big institutional buyers, public and private BDS providers as well the municipal LED office. Semi-structured interviews were conducted with each stakeholder using questions shown in appendixes A to D. Perceptions of all key stakeholders were very positive with good intentions to support SMMEs. However, this was not consistent with procurement practice at the big institutional buyers. Constraints are summarized in the following five themes: Theme 1. Inconsistent practice in dealing with SMMEs across the organisation. Theme 2. Absence of a cooperative body or Chamber of Commerce. Theme 3. Fragmented Business Development Services. Theme 4. A lack of a culture of cost recovery. Theme 5. Limited awareness of BDS in the Makana area. A number of recommendations were suggested. Big institutional buyers like Rhodes University and Makana municipality need to take a longer term view and move the focus from employment creation to enterprise support which is a more sustainable and empowering source of employment (ILO, 2009). The Grahamstown Chamber of Commerce should become more representative and big institutional buyers also need to be convinced of the value of private BDS. Stakeholders should work together to combine resources to offer a comprehensive one-stop BDS for the Makana area (Chetty, 2009) and this comprehensive BDS should be provided according to the Market Development approach focusing on those services that lend themselves better to this approach whilst using subsidies only for those services with a low potential for cost recovery (UNDP, 2004).
- Full Text:
- Authors: Van Heerden, Garth William
- Date: 2012
- Subjects: Makana Municipality Local government -- South Africa -- Eastern Cape Small business -- South Africa -- Eastern Cape Small business -- South Africa -- Eastern Cape -- Growth Small business -- South Africa -- Eastern Cape -- Public opinion Small business marketing -- South Africa -- Eastern Cape Economic development -- South Africa -- Eastern Cape Unemployment -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:814 , http://hdl.handle.net/10962/d1007746
- Description: South Africa's biggest challenge remains the high rate of unemployment especially among the country's youth. Small, medium and micro enterprises (SMMEs) have been shown to be instrumental in many third world economies as a sustainable means not only to address unemployment but also to contribute significantly to economic growth. Despite government's good intentions and support, the South African SMME sector is not growing as expected and this is impacting negatively on unemployment creation in the country. Good business development services (BDS) is necessary to support SMMEs and specifically the Market Development Approach to the provision of BDS, where subsidies are replaced by private payment for services. Makana municipal area provided scope for analysing the constraints to the implementation of such business development services. Analysing the scope and magnitude of the constraints in this setting would contribute to understanding the constraints also in other parts of the country and help officials in local economic development make better informed decisions regarding support to SMMEs. Authors like Rogerson (2011), UNDP (2004), Miehlbradt and McVay, (2003), the Committee of Donor Agencies for SME Development (Blue book) (2001) and Bear et al., (2001) Gibson (2001), propose that the key to sustainable BDS is the implementation of the Market Development approach which focusses on for-profit activities in the provision of BDS to SMMEs. The aim of this study was to examine perceptions of key stakeholders towards SMME support and development, to identify the constraints to the implementation of a Market Development approach to the provision of business development services to SMMEs in the Makana area and to make recommendations to the Makana LED office of possible intervention strategies to address identified constraints. Purposive sampling was used to identify key stakeholders in SMME support in the Makana area in the categories of, big institutional buyers, public and private BDS providers as well the municipal LED office. Semi-structured interviews were conducted with each stakeholder using questions shown in appendixes A to D. Perceptions of all key stakeholders were very positive with good intentions to support SMMEs. However, this was not consistent with procurement practice at the big institutional buyers. Constraints are summarized in the following five themes: Theme 1. Inconsistent practice in dealing with SMMEs across the organisation. Theme 2. Absence of a cooperative body or Chamber of Commerce. Theme 3. Fragmented Business Development Services. Theme 4. A lack of a culture of cost recovery. Theme 5. Limited awareness of BDS in the Makana area. A number of recommendations were suggested. Big institutional buyers like Rhodes University and Makana municipality need to take a longer term view and move the focus from employment creation to enterprise support which is a more sustainable and empowering source of employment (ILO, 2009). The Grahamstown Chamber of Commerce should become more representative and big institutional buyers also need to be convinced of the value of private BDS. Stakeholders should work together to combine resources to offer a comprehensive one-stop BDS for the Makana area (Chetty, 2009) and this comprehensive BDS should be provided according to the Market Development approach focusing on those services that lend themselves better to this approach whilst using subsidies only for those services with a low potential for cost recovery (UNDP, 2004).
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Contrasting habitat associations of imperilled endemic stream fishes from a global biodiversity hot spot
- Chakona, Albert, Swartz, Ernst R
- Authors: Chakona, Albert , Swartz, Ernst R
- Date: 2012
- Language: English
- Type: Article
- Identifier: vital:7148 , http://hdl.handle.net/10962/d1011850 , http://www.biomedcentral.com/1472-6785/12/19
- Description: Knowledge of the factors that drive species distributions provides a fundamental baseline for several areas of research including biogeography, phylogeography and biodiversity conservation. Data from 148 minimally disturbed sites across a large drainage system in the Cape Floristic Region of South Africa were used to test the hypothesis that stream fishes have similar responses to environmental determinants of species distribution. Two complementary statistical approaches, boosted regression trees and hierarchical partitioning, were used to model the responses of four fish species to 11 environmental predictors, and to quantify the independent explanatory power of each predictor.
- Full Text:
- Authors: Chakona, Albert , Swartz, Ernst R
- Date: 2012
- Language: English
- Type: Article
- Identifier: vital:7148 , http://hdl.handle.net/10962/d1011850 , http://www.biomedcentral.com/1472-6785/12/19
- Description: Knowledge of the factors that drive species distributions provides a fundamental baseline for several areas of research including biogeography, phylogeography and biodiversity conservation. Data from 148 minimally disturbed sites across a large drainage system in the Cape Floristic Region of South Africa were used to test the hypothesis that stream fishes have similar responses to environmental determinants of species distribution. Two complementary statistical approaches, boosted regression trees and hierarchical partitioning, were used to model the responses of four fish species to 11 environmental predictors, and to quantify the independent explanatory power of each predictor.
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Contribution towards the development of a management plan for the baitboat and sport fishery for tuna in South Africa
- Authors: Newcombe, Hylton Cecil
- Date: 2012
- Subjects: Tuna -- South Africa , Tuna fishing -- South Africa , Fishery management -- South Africa , Fishery management -- Economic aspects -- South Africa , Tuna fisheries -- Catch effort -- South Africa , Tuna fisheries -- Economic aspects -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5249 , http://hdl.handle.net/10962/d1005092 , Tuna -- South Africa , Tuna fishing -- South Africa , Fishery management -- South Africa , Fishery management -- Economic aspects -- South Africa , Tuna fisheries -- Catch effort -- South Africa , Tuna fisheries -- Economic aspects -- South Africa
- Description: Tuna are of significant global economic importance and a prime food source. Increased levels of fishing have resulted in many stocks being under threat and a number of species are considered to be overfished. The South African tuna industry has had limited management attention from the South African fisheries management agency. A recent development has been an increase in the number of tuna caught by small vessels that target the fresh tuna market in South Africa and overseas. This has highlighted the importance of developing a holistic management plan for the sector and creating an awareness, among vessel owners, of the importance of compliance with initiatives such as the Marine Stewardship Council (MSC). The South African tuna fishery comprises three sectors: baitboat, sport and longline, all of which are currently in need of acquiring more biological and fisheries data. This project was initiated to collate existing information and to collect additional information where possible. This encompassed a qualitative and quantitative assessment of the size and shape of the tuna fishing industry, which included estimates of total catch, effort, catch-per-unit-of-effort (CPUE) and stock structure (obtained through comparative estimates of age and growth), as well as socio-economic and economic information. A technique involving an examination of specific vertebrae was used to obtain age-growth information for T. albacares. These data were used to estimate von Bertalanffy (VBGF) growth parameters: F 2 1. , k 0.1 , and t₀ -0. 1 year. No significant differences in growth parameters were found in yellowfin tuna (Thunnus albacares) from different localities around the South African coast, i.e. from the south eastern Atlantic and the south western Indian Ocean. In addition, growth did not differ between South Africa and other regions (Draganic and Pelzcarski 1984, Fonteneau 1980, Gascuel et al. 1992, LeGuen and Sakagawa 1973, Lehodey and Leroy 1999, Lessa and Duarte-Neto 2004, Shuford et al. 2007, Stequert et al. 1996, Wild 1986, Yang et al. 1969). Further substantiation of the above-mentioned observations was found by recording differences in the sizes of fish caught in the inshore (baitboat and sport fishery vessels) and offshore (large pelagic longline vessels) sectors of South African tuna fisheries. A significant difference between the regions — in terms of the size of fish caught inshore — was noted, with mostly-juvenile fish being caught in KwaZulu-Natal (5.4 ± 3.5kg), sub-adult fish in the Eastern Cape (26.2 ± 13.4kg), and adult fish in the Western Cape (42.3 ± 14.4kg). Since mostly-adult fish were caught offshore by longliners, with no significant differences between regions, it is however possible th at adult fish predominantly inhabit the offshore region. Yellowfin tuna caught by the large pelagic longline fishery in the three managerial zones (A, B and C) were predominantly adult fish of similar size, namely Zone A: 38.9 ± 6.9kg; Zone B: 28.7 ± 4.6kg, and Zone C: 36.0 ± 5.1kg. The recreational ski boat sport fishery has remained stable, in terms of participation, consisting mostly of white middle aged males in the top 25% of household income distribution, having either permanent occupational status or being retired. Fishers within this sector are willing to incur great expense to partake in the fishery and they provide an important economic contribution to coastal towns, particularly in the Eastern Cape. The total catch (of 83t) of yellowfin tuna by the competitive sport fishery within the Western and Eastern Cape regions was considerably lower than that of commercial tuna baitboat catches, which amounted to 186t, and the large pelagic longline sector that caught t in 200. It is however likely that the competitive sport fishery's total yellowfin tuna catch (of 83t in 2009) of the Eastern and Western Cape competitive sport fishery was considerably less than the total yellowfin tuna catches of the whole South African deep-sea sport fishery. Longfin tuna are the primary target species of South Africa‘s baitboat fisheries, comprising an average of 86% of the total catch and generating ZAR49 million in employment income in 2002. South Africa was responsible for 20% of the total longfin tuna annual yield in 2004 in the southern Atlantic Ocean, behind Taiwan with 59%. However, yellowfin tuna only contributes a small percentage towards total catches (8.4 ± 8.2% between 1995 and 2009), generating ZAR1.3 million in employment income in 2002. Of the four vessel categories comprising the tuna baitboat fishery, ski boats had the highest yellowfin tuna CPUE in 2009 (117 ± 62 kg.vessel⁻¹.day⁻¹) and the lowest effort. The ski boats sector is the most opportunistic fishery as they are only active when either longfin or yellowfin tuna are in high abundance. At such times catches are guaranteed, so can be expected to offset expenses. In 2009 the CPUE for yellowfin tuna for 15–19m vessels and freezer deckboats was 12 ± 20kg.vessel⁻¹.day⁻¹ and 3 ± 6kg.vessel⁻¹.day⁻¹, respectively. These vessels specifically target longfin tuna when they are in abundance. Since the start of the tuna baitboat fishery in 1995, there has been a substantial increase in the number of new entrants. In 2002 this sector had a fleet size of 82 vessels with a capital value of ZAR163 million and a total employment income of ZAR58 million, employing 2 173 fishers, of which 87% were black African. The commercial tuna baitboat fleet has subsequently grown to 200 vessels and 3600 crew, with 110 active vessels fishing for a combined fleet average of 46 days per year. There are a high number of owner-operated vessels. Since 2007 the fishery's profit to cost ratio has been low due to the low abundance of tuna stocks off the coast of South Africa, which has resulted in poor catch returns, placing economic pressure on the fishery. The baitboat industry is a low-profit-margin fishery with a total net catch value worth ZAR90 million in 2009 (Feike 2010). The abundance of yellowfin tuna influences profit margins, with very high profits being made when abundance and catches are high. The large pelagic longline fishery has a total allowable effort of 43 vessels of which only 30 vessels fished during 2009, when a reported 766t of yellowfin tuna were caught, representing a total tonnage far in excess of that obtained by the combined effort of the baitboat and sport fishery. It is, however, assumed that considerable underreporting of catches takes place within this fishery, which means that the estimated total net catch value of ZAR100 million could, in fact, be much higher. Such underreporting of catches is of great concern for this fishery, as is the high bycatch of Chondricthians spp. that significantly outweighs imposed regulatory limits (DEAT 2007). The present study demonstrates the current lack of comprehensive catch and effort data for the sport, baitboat and longline fisheries as well as the serious limitations and flaws associated with current databases. Results from the present study have drawn attention to a number of high-priority research needs, as outlined below. (1) A major lack of comprehensive catch and effort data for the sport fishery, which can be rectified by focussing on obtaining more competition data, as well as high-quality catch and effort and socio-economic information, as opposed to relying on information from non-club anglers (Gartside et al. 1999, Williams 2003, Cass-Calay 2008). Acquisition of such data is relatively inexpensive: the location of organized clubs and their frequent competition meetings provide widespread coverage along the Southern African coastline. Such data acquisition efforts have the potential to provide reliable information on spatial catch trends. (2) Validation of vessel catch return data is required for commercial fisheries and on some recent data that has emerged from studies of catch rates and trends for target species, particularly in the longline fishery. In this context it should be noted that the most recent peer-reviewed publications on this exploratory fishery were published more than a decade ago (Kroese 1999, Penny and Griffiths 1999). Additional studies need to be undertaken and journal articles published on the current stock status of South African catches of yellowfin and bigeye tuna and swordfish.
- Full Text:
- Authors: Newcombe, Hylton Cecil
- Date: 2012
- Subjects: Tuna -- South Africa , Tuna fishing -- South Africa , Fishery management -- South Africa , Fishery management -- Economic aspects -- South Africa , Tuna fisheries -- Catch effort -- South Africa , Tuna fisheries -- Economic aspects -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5249 , http://hdl.handle.net/10962/d1005092 , Tuna -- South Africa , Tuna fishing -- South Africa , Fishery management -- South Africa , Fishery management -- Economic aspects -- South Africa , Tuna fisheries -- Catch effort -- South Africa , Tuna fisheries -- Economic aspects -- South Africa
- Description: Tuna are of significant global economic importance and a prime food source. Increased levels of fishing have resulted in many stocks being under threat and a number of species are considered to be overfished. The South African tuna industry has had limited management attention from the South African fisheries management agency. A recent development has been an increase in the number of tuna caught by small vessels that target the fresh tuna market in South Africa and overseas. This has highlighted the importance of developing a holistic management plan for the sector and creating an awareness, among vessel owners, of the importance of compliance with initiatives such as the Marine Stewardship Council (MSC). The South African tuna fishery comprises three sectors: baitboat, sport and longline, all of which are currently in need of acquiring more biological and fisheries data. This project was initiated to collate existing information and to collect additional information where possible. This encompassed a qualitative and quantitative assessment of the size and shape of the tuna fishing industry, which included estimates of total catch, effort, catch-per-unit-of-effort (CPUE) and stock structure (obtained through comparative estimates of age and growth), as well as socio-economic and economic information. A technique involving an examination of specific vertebrae was used to obtain age-growth information for T. albacares. These data were used to estimate von Bertalanffy (VBGF) growth parameters: F 2 1. , k 0.1 , and t₀ -0. 1 year. No significant differences in growth parameters were found in yellowfin tuna (Thunnus albacares) from different localities around the South African coast, i.e. from the south eastern Atlantic and the south western Indian Ocean. In addition, growth did not differ between South Africa and other regions (Draganic and Pelzcarski 1984, Fonteneau 1980, Gascuel et al. 1992, LeGuen and Sakagawa 1973, Lehodey and Leroy 1999, Lessa and Duarte-Neto 2004, Shuford et al. 2007, Stequert et al. 1996, Wild 1986, Yang et al. 1969). Further substantiation of the above-mentioned observations was found by recording differences in the sizes of fish caught in the inshore (baitboat and sport fishery vessels) and offshore (large pelagic longline vessels) sectors of South African tuna fisheries. A significant difference between the regions — in terms of the size of fish caught inshore — was noted, with mostly-juvenile fish being caught in KwaZulu-Natal (5.4 ± 3.5kg), sub-adult fish in the Eastern Cape (26.2 ± 13.4kg), and adult fish in the Western Cape (42.3 ± 14.4kg). Since mostly-adult fish were caught offshore by longliners, with no significant differences between regions, it is however possible th at adult fish predominantly inhabit the offshore region. Yellowfin tuna caught by the large pelagic longline fishery in the three managerial zones (A, B and C) were predominantly adult fish of similar size, namely Zone A: 38.9 ± 6.9kg; Zone B: 28.7 ± 4.6kg, and Zone C: 36.0 ± 5.1kg. The recreational ski boat sport fishery has remained stable, in terms of participation, consisting mostly of white middle aged males in the top 25% of household income distribution, having either permanent occupational status or being retired. Fishers within this sector are willing to incur great expense to partake in the fishery and they provide an important economic contribution to coastal towns, particularly in the Eastern Cape. The total catch (of 83t) of yellowfin tuna by the competitive sport fishery within the Western and Eastern Cape regions was considerably lower than that of commercial tuna baitboat catches, which amounted to 186t, and the large pelagic longline sector that caught t in 200. It is however likely that the competitive sport fishery's total yellowfin tuna catch (of 83t in 2009) of the Eastern and Western Cape competitive sport fishery was considerably less than the total yellowfin tuna catches of the whole South African deep-sea sport fishery. Longfin tuna are the primary target species of South Africa‘s baitboat fisheries, comprising an average of 86% of the total catch and generating ZAR49 million in employment income in 2002. South Africa was responsible for 20% of the total longfin tuna annual yield in 2004 in the southern Atlantic Ocean, behind Taiwan with 59%. However, yellowfin tuna only contributes a small percentage towards total catches (8.4 ± 8.2% between 1995 and 2009), generating ZAR1.3 million in employment income in 2002. Of the four vessel categories comprising the tuna baitboat fishery, ski boats had the highest yellowfin tuna CPUE in 2009 (117 ± 62 kg.vessel⁻¹.day⁻¹) and the lowest effort. The ski boats sector is the most opportunistic fishery as they are only active when either longfin or yellowfin tuna are in high abundance. At such times catches are guaranteed, so can be expected to offset expenses. In 2009 the CPUE for yellowfin tuna for 15–19m vessels and freezer deckboats was 12 ± 20kg.vessel⁻¹.day⁻¹ and 3 ± 6kg.vessel⁻¹.day⁻¹, respectively. These vessels specifically target longfin tuna when they are in abundance. Since the start of the tuna baitboat fishery in 1995, there has been a substantial increase in the number of new entrants. In 2002 this sector had a fleet size of 82 vessels with a capital value of ZAR163 million and a total employment income of ZAR58 million, employing 2 173 fishers, of which 87% were black African. The commercial tuna baitboat fleet has subsequently grown to 200 vessels and 3600 crew, with 110 active vessels fishing for a combined fleet average of 46 days per year. There are a high number of owner-operated vessels. Since 2007 the fishery's profit to cost ratio has been low due to the low abundance of tuna stocks off the coast of South Africa, which has resulted in poor catch returns, placing economic pressure on the fishery. The baitboat industry is a low-profit-margin fishery with a total net catch value worth ZAR90 million in 2009 (Feike 2010). The abundance of yellowfin tuna influences profit margins, with very high profits being made when abundance and catches are high. The large pelagic longline fishery has a total allowable effort of 43 vessels of which only 30 vessels fished during 2009, when a reported 766t of yellowfin tuna were caught, representing a total tonnage far in excess of that obtained by the combined effort of the baitboat and sport fishery. It is, however, assumed that considerable underreporting of catches takes place within this fishery, which means that the estimated total net catch value of ZAR100 million could, in fact, be much higher. Such underreporting of catches is of great concern for this fishery, as is the high bycatch of Chondricthians spp. that significantly outweighs imposed regulatory limits (DEAT 2007). The present study demonstrates the current lack of comprehensive catch and effort data for the sport, baitboat and longline fisheries as well as the serious limitations and flaws associated with current databases. Results from the present study have drawn attention to a number of high-priority research needs, as outlined below. (1) A major lack of comprehensive catch and effort data for the sport fishery, which can be rectified by focussing on obtaining more competition data, as well as high-quality catch and effort and socio-economic information, as opposed to relying on information from non-club anglers (Gartside et al. 1999, Williams 2003, Cass-Calay 2008). Acquisition of such data is relatively inexpensive: the location of organized clubs and their frequent competition meetings provide widespread coverage along the Southern African coastline. Such data acquisition efforts have the potential to provide reliable information on spatial catch trends. (2) Validation of vessel catch return data is required for commercial fisheries and on some recent data that has emerged from studies of catch rates and trends for target species, particularly in the longline fishery. In this context it should be noted that the most recent peer-reviewed publications on this exploratory fishery were published more than a decade ago (Kroese 1999, Penny and Griffiths 1999). Additional studies need to be undertaken and journal articles published on the current stock status of South African catches of yellowfin and bigeye tuna and swordfish.
- Full Text:
Conveniencing the family in agri-based processing enterprise : a grounded theory study of strategic leaders' cultural assumptions and strategising activities
- Authors: Kanyangale, Macdonald Isaac
- Date: 2012
- Subjects: Small business -- Malawi -- Management Agriculture -- Malawi -- Business management Agriculture -- Economic aspects -- Malawi Grounded theory -- Study and teaching
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1181 , http://hdl.handle.net/10962/d1002798
- Description: As leaders of small and medium enterprises (SMEs), strategic leaders are responsible for strategising, the approach to which is influenced by their cultural paradigm. The effects of this strategising are manifested in the day-to-day activities of these leaders. This study aims to build an understanding of the shared cultural assumptions of strategic leaders in agri-based processing SMEs and how these assumptions affect the strategising activities that are adopted when addressing critical incidents related to the internal integration and external adaptation of the SME. Using Strauss and Corbin‟s (1990) grounded theory method, this study develops a theory titled Conveniencing the Family in Business, which is induced from critical incidents. A sample of critical incidents was gathered from 44 qualitative interviews conducted with strategic leaders of various agri-based processing SMEs operating in Malawi. This study found that strategic leaders display persistent and stable pragmatic business survival mind sets, but dynamic cultural assumptions about relationships with organisation members. The cultural influence of these assumptions is manifested in two distinctive and alternative processes making up the theory of conveniencing the family in business. These are the humanising and commodifying of relationships with organisation members, and they are evident in hostile and friendly business environments, respectively. Humanising of relationships with all members of the organisation builds and capitalises on inclusive, organisation-wide social capital that secures the future of the business. On the other hand, commodifying of relationships with non-family organisation members weakens collective support, which becomes mainly dependent on family and friendship ties. Thus, commodifying of relationships serves to perpetuate the close integration of business activity and family requirements to ultimately convenience the family in business, and represents the desired modus operandi of strategic leaders. As strategic leaders of SMEs have not yet conceptualised this, providing them with the conceptual theory developed here may be helpful towards a consistent re-orientation of the internal organisational support in a way that does not exclude but rather harnesses the wider solidarity of organisation members. The process explained by this theory is iterative, dynamic and distinguishes patterns of relationships amongst organisation members, which either enhances or compromises their collective support for the leaders and the enterprise. This by implication affects the performance of the enterprise. The results of this study are discussed from the perspective of social exchange and social capital theory, thereby contributing to the understanding of the strategising activities of strategic leaders, as well as the processes of building or destroying social capital in this type of enterprise.
- Full Text:
- Authors: Kanyangale, Macdonald Isaac
- Date: 2012
- Subjects: Small business -- Malawi -- Management Agriculture -- Malawi -- Business management Agriculture -- Economic aspects -- Malawi Grounded theory -- Study and teaching
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1181 , http://hdl.handle.net/10962/d1002798
- Description: As leaders of small and medium enterprises (SMEs), strategic leaders are responsible for strategising, the approach to which is influenced by their cultural paradigm. The effects of this strategising are manifested in the day-to-day activities of these leaders. This study aims to build an understanding of the shared cultural assumptions of strategic leaders in agri-based processing SMEs and how these assumptions affect the strategising activities that are adopted when addressing critical incidents related to the internal integration and external adaptation of the SME. Using Strauss and Corbin‟s (1990) grounded theory method, this study develops a theory titled Conveniencing the Family in Business, which is induced from critical incidents. A sample of critical incidents was gathered from 44 qualitative interviews conducted with strategic leaders of various agri-based processing SMEs operating in Malawi. This study found that strategic leaders display persistent and stable pragmatic business survival mind sets, but dynamic cultural assumptions about relationships with organisation members. The cultural influence of these assumptions is manifested in two distinctive and alternative processes making up the theory of conveniencing the family in business. These are the humanising and commodifying of relationships with organisation members, and they are evident in hostile and friendly business environments, respectively. Humanising of relationships with all members of the organisation builds and capitalises on inclusive, organisation-wide social capital that secures the future of the business. On the other hand, commodifying of relationships with non-family organisation members weakens collective support, which becomes mainly dependent on family and friendship ties. Thus, commodifying of relationships serves to perpetuate the close integration of business activity and family requirements to ultimately convenience the family in business, and represents the desired modus operandi of strategic leaders. As strategic leaders of SMEs have not yet conceptualised this, providing them with the conceptual theory developed here may be helpful towards a consistent re-orientation of the internal organisational support in a way that does not exclude but rather harnesses the wider solidarity of organisation members. The process explained by this theory is iterative, dynamic and distinguishes patterns of relationships amongst organisation members, which either enhances or compromises their collective support for the leaders and the enterprise. This by implication affects the performance of the enterprise. The results of this study are discussed from the perspective of social exchange and social capital theory, thereby contributing to the understanding of the strategising activities of strategic leaders, as well as the processes of building or destroying social capital in this type of enterprise.
- Full Text:
Cooperative wasp-killing by mixed-species colonies of honeybees, Apis cerana and Apis mellifera
- Tan, K, Yang, M-Y, Li, H, Zhang, Z-L, Radloff, Sarah E, Hepburn, H Randall
- Authors: Tan, K , Yang, M-Y , Li, H , Zhang, Z-L , Radloff, Sarah E , Hepburn, H Randall
- Date: 2012
- Language: English
- Type: text , Article
- Identifier: vital:6838 , http://hdl.handle.net/10962/d1010979 , http://dx.doi.org/10.1007/s13592-011-0098-5
- Description: The cooperative defensive behaviour of mixed-species colonies of honeybees, Apis cerana and Apis mellifera, were tested against a predatory wasp, Vespa velutina. When vespine wasps hawk honeybees at their nest entrances, the difference in the numbers of bees involved in heat-balling among pure species and mixed-species colonies was not significantly different. However, in the mixed colonies, the numbers of A. cerana and A. mellifera workers involved in heat-balling were significantly different. The duration of heat-balling among these three groups was significantly different. During heat-balling, guard bees of both species in mixed colonies raised their thoracic temperatures and the core temperatures of the heat-balls were about 45°C, which is not significantly different from that of the pure species. These results suggest that the two species of honeybees can cooperate in joint heat-balling against the wasps, but A. cerana was more assertive in such defence.
- Full Text: false
- Authors: Tan, K , Yang, M-Y , Li, H , Zhang, Z-L , Radloff, Sarah E , Hepburn, H Randall
- Date: 2012
- Language: English
- Type: text , Article
- Identifier: vital:6838 , http://hdl.handle.net/10962/d1010979 , http://dx.doi.org/10.1007/s13592-011-0098-5
- Description: The cooperative defensive behaviour of mixed-species colonies of honeybees, Apis cerana and Apis mellifera, were tested against a predatory wasp, Vespa velutina. When vespine wasps hawk honeybees at their nest entrances, the difference in the numbers of bees involved in heat-balling among pure species and mixed-species colonies was not significantly different. However, in the mixed colonies, the numbers of A. cerana and A. mellifera workers involved in heat-balling were significantly different. The duration of heat-balling among these three groups was significantly different. During heat-balling, guard bees of both species in mixed colonies raised their thoracic temperatures and the core temperatures of the heat-balls were about 45°C, which is not significantly different from that of the pure species. These results suggest that the two species of honeybees can cooperate in joint heat-balling against the wasps, but A. cerana was more assertive in such defence.
- Full Text: false