The biotechnology of effluent-grown Spirulina, and application in aquaculture nutrition
- Authors: Maart, Brenton Ashley
- Date: 1993
- Subjects: Aquaculture , Spirulina , Algae -- Biotechnology , Fishes -- Feeding and feeds
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4050 , http://hdl.handle.net/10962/d1004111 , Aquaculture , Spirulina , Algae -- Biotechnology , Fishes -- Feeding and feeds
- Description: The biotechnology of production and utilisation of the cyanobacterium Spirulina has been well documented. Research has centred mainly on application in human and animal nutrition, and has been motivated by the high protein, vitamin, fatty acid and growth factor contents. The main obstacle in realising the full potential of this feed source has been the high production costs associated with its mass culture in defined media. The observation of blooms of Spirulina in tannery effluent evaporation ponds in Wellington, South Africa, prompted this investigation into the harvesting, and nutritional and toxicological evaluation of this potentially low-cost production system, with the ultimate aim of using the product in aquaculture rations. An investigation of the chemical gradient along the evaporation cascade showed a positive correlation between the prevailing chemical conditions and the dominant species populations. A standing crop of 9.5 tonnes/ha of Spirulina was found to be present in the latter alkaline ponds, characterised by relatively lower organic and sulphur contents. Initial harvesting of the biomass was achieved by the design, construction and implementation of a small-scale screen harvest, which yielded a 25 kg (dry weight) crop. A scale-up model was then designed, and implemented in a technical scale harvest, yielding a crop of 250 kg (dry weight). Both these harvests utilised the bloom of surface-autoflocculated biomass. Concentrated cell slurries were sun-dried on muslin beds, and milled to a coarse powder. An evaluation of the harvest revealed a chemical content similar to other published reports of defined media cultures, with the exception of the protein and amino acid contents. The observed lower levels of the latter two are almost certainly due to the sun-drying method employed, known to reduce the protein content due to thermal denaturation. Legislation demands the strict toxicological evaluation of new protein sources, and because of the effluent-nature of the growth medium of this source of Spirulina, its viability lies only in the application as an animal feed or supplement. A range of toxicological tests were chosen that were targeted to elucidate the possible toxicological constraints of this effluentgrown source of protein in animal nutrition. The nucleic acid and pesticide contents of the harvested biomass were within the prescribed safety ranges. Atomic absorption showed minimal accumulation of minerals and heavy metals from the effluent. A bioassay with the brine shrimp Anemia salina showed that the biomass contained no toxicologically active water-soluble components. A short term feeding trial with new-born chicks showed that supplementation with Spirulina had no effect on the growth rates and feed conversion ratios of the different feeding groups. Pathological analyses showed that the liver was the only target organ to elicit a change in response to supplementation of the diets with Spirulina. A general decrease in liver weight was noted, with Cu, Ca, Fe and Zn being significantly accumulated. A histopathological examination however, showed no cellular and functional aberration from the control animals. The toxicological analyses gave the preliminary safe go-ahead for the evaluation of effluent-grown Spirulina in aquaculture nutrition. The South African abalone Haliotis midae, and the rainbow trout Oncorhynchus mykiss were chosen as representative species of edible cultured organisms. The technology for the culture of the perlemoen abalone is being established in South Africa, with the main area of research being the development of an artificial diet for high density culture. A 40 day growth trial demonstrated that lower concentrations of Spirulina supplemented to an agar-based fishmeal diet resulted in growth rates and feed conversion ratios similar to the control fishmeal and purified-casein diets, and thus has application potential in the nutrition of this high-cost marine delicacy. The aquaculture technology of freshwater rainbow trout is already well established. An eight week feeding trial with various concentrations of Spirulina showed that this effluent-grown protein source can partially replace fishmeal in semi-purified diets. Fish fed Spirulina did not exhibit decisive manifestations of toxicity, as determined in a histopathological study. In addition, Spirulina supplementation resulted in enhanced colouration of the skin and flesh, which may have implications in the aesthetic marketing of this sought-after table fish. The primary aim of this preliminary investigation thus concerned the determination of the biotechnological potential of this effluent-source of Spirulina. A technology transfer from the economically unfeasible defined-media culture was implemented. This project is ultimately aimed as a contribution towards the treatment of tannery wastewater, by the removal of contaminants from the effluent in the form of organic biomass.
- Full Text:
- Date Issued: 1993
- Authors: Maart, Brenton Ashley
- Date: 1993
- Subjects: Aquaculture , Spirulina , Algae -- Biotechnology , Fishes -- Feeding and feeds
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4050 , http://hdl.handle.net/10962/d1004111 , Aquaculture , Spirulina , Algae -- Biotechnology , Fishes -- Feeding and feeds
- Description: The biotechnology of production and utilisation of the cyanobacterium Spirulina has been well documented. Research has centred mainly on application in human and animal nutrition, and has been motivated by the high protein, vitamin, fatty acid and growth factor contents. The main obstacle in realising the full potential of this feed source has been the high production costs associated with its mass culture in defined media. The observation of blooms of Spirulina in tannery effluent evaporation ponds in Wellington, South Africa, prompted this investigation into the harvesting, and nutritional and toxicological evaluation of this potentially low-cost production system, with the ultimate aim of using the product in aquaculture rations. An investigation of the chemical gradient along the evaporation cascade showed a positive correlation between the prevailing chemical conditions and the dominant species populations. A standing crop of 9.5 tonnes/ha of Spirulina was found to be present in the latter alkaline ponds, characterised by relatively lower organic and sulphur contents. Initial harvesting of the biomass was achieved by the design, construction and implementation of a small-scale screen harvest, which yielded a 25 kg (dry weight) crop. A scale-up model was then designed, and implemented in a technical scale harvest, yielding a crop of 250 kg (dry weight). Both these harvests utilised the bloom of surface-autoflocculated biomass. Concentrated cell slurries were sun-dried on muslin beds, and milled to a coarse powder. An evaluation of the harvest revealed a chemical content similar to other published reports of defined media cultures, with the exception of the protein and amino acid contents. The observed lower levels of the latter two are almost certainly due to the sun-drying method employed, known to reduce the protein content due to thermal denaturation. Legislation demands the strict toxicological evaluation of new protein sources, and because of the effluent-nature of the growth medium of this source of Spirulina, its viability lies only in the application as an animal feed or supplement. A range of toxicological tests were chosen that were targeted to elucidate the possible toxicological constraints of this effluentgrown source of protein in animal nutrition. The nucleic acid and pesticide contents of the harvested biomass were within the prescribed safety ranges. Atomic absorption showed minimal accumulation of minerals and heavy metals from the effluent. A bioassay with the brine shrimp Anemia salina showed that the biomass contained no toxicologically active water-soluble components. A short term feeding trial with new-born chicks showed that supplementation with Spirulina had no effect on the growth rates and feed conversion ratios of the different feeding groups. Pathological analyses showed that the liver was the only target organ to elicit a change in response to supplementation of the diets with Spirulina. A general decrease in liver weight was noted, with Cu, Ca, Fe and Zn being significantly accumulated. A histopathological examination however, showed no cellular and functional aberration from the control animals. The toxicological analyses gave the preliminary safe go-ahead for the evaluation of effluent-grown Spirulina in aquaculture nutrition. The South African abalone Haliotis midae, and the rainbow trout Oncorhynchus mykiss were chosen as representative species of edible cultured organisms. The technology for the culture of the perlemoen abalone is being established in South Africa, with the main area of research being the development of an artificial diet for high density culture. A 40 day growth trial demonstrated that lower concentrations of Spirulina supplemented to an agar-based fishmeal diet resulted in growth rates and feed conversion ratios similar to the control fishmeal and purified-casein diets, and thus has application potential in the nutrition of this high-cost marine delicacy. The aquaculture technology of freshwater rainbow trout is already well established. An eight week feeding trial with various concentrations of Spirulina showed that this effluent-grown protein source can partially replace fishmeal in semi-purified diets. Fish fed Spirulina did not exhibit decisive manifestations of toxicity, as determined in a histopathological study. In addition, Spirulina supplementation resulted in enhanced colouration of the skin and flesh, which may have implications in the aesthetic marketing of this sought-after table fish. The primary aim of this preliminary investigation thus concerned the determination of the biotechnological potential of this effluent-source of Spirulina. A technology transfer from the economically unfeasible defined-media culture was implemented. This project is ultimately aimed as a contribution towards the treatment of tannery wastewater, by the removal of contaminants from the effluent in the form of organic biomass.
- Full Text:
- Date Issued: 1993
Khoisan revivalism: the claims of Africa’s first indigenous peoples: racism and the media
- Authors: Garman, Anthea
- Date: 2001
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/${Handle} , vital:40222 , https://hdl.handle.net/10520/EJC144705
- Description: An unexpected development in post-apartheid South Africa is the revivalism of Khoisan identity, the truly indigenous of the country whose blood flows through many who now know themselves by different names.
- Full Text:
- Date Issued: 2001
- Authors: Garman, Anthea
- Date: 2001
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/${Handle} , vital:40222 , https://hdl.handle.net/10520/EJC144705
- Description: An unexpected development in post-apartheid South Africa is the revivalism of Khoisan identity, the truly indigenous of the country whose blood flows through many who now know themselves by different names.
- Full Text:
- Date Issued: 2001
Comparative study of clan CA cysteine proteases: an insight into the protozoan parasites
- Authors: Moyo, Sipho Dugunye
- Date: 2015
- Subjects: Cysteine proteinases , Proteolytic enzymes , Protozoan diseases , Parasites , Protozoan diseases -- Chemotherapy , Bioinformatics , Plasmodium , Antiprotozoal agents
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4165 , http://hdl.handle.net/10962/d1020309
- Description: Protozoan infections such as Malaria, Leishmaniasis, Toxoplasmosis, Chaga’s disease and African trypanosomiasis caused by the Plasmodium, Leishmania, Toxoplasma and Trypanosoma genuses respectively; inflict a huge economic, health and social impact in endemic regions particularly tropical and sub-tropical regions. The combined infections are estimated at over a billion annually and approximately 1.1 million deaths annually. The global burden of the protozoan infections is worsened by the increased drug resistance, toxicity and the relatively high cost of treatment and prophylaxis. Therefore there has been a high demand for new drugs and drug targets that play a role in parasite virulence. Cysteine proteases have been validated as viable drug targets due to their role in the infectivity stage of the parasites within the human host. There is a variety of cysteine proteases hence they are subdivided into families and in this study we focus on the clan CA, papain family C1 proteases. The current inhibitors for the protozoan cysteine proteases lack selectivity and specificity which contributes to drug toxicity. Therefore there is a need to identify the differences and similarities between the host, vector and protozoan proteases. This study uses a variety of bioinformatics tools to assess these differences and similarities. The Plasmodium cysteine protease FP-2 is the most characterized protease hence it was used as a reference to all the other proteases and its homologs were retrieved, aligned and the evolutionary relationships established. The homologs were also analysed for common motifs and the physicochemical properties determined which were validated using the Kruskal-Wallis test. These analyses revealed that the host and vector cathepsins share similar properties while the parasite cathepsins differ. At sub-site level sub-site 2 showed greater variations suggesting diverse ligand specificity within the proteases, a revelation that is vital in the design of antiprotozoan inhibitors.
- Full Text:
- Date Issued: 2015
- Authors: Moyo, Sipho Dugunye
- Date: 2015
- Subjects: Cysteine proteinases , Proteolytic enzymes , Protozoan diseases , Parasites , Protozoan diseases -- Chemotherapy , Bioinformatics , Plasmodium , Antiprotozoal agents
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4165 , http://hdl.handle.net/10962/d1020309
- Description: Protozoan infections such as Malaria, Leishmaniasis, Toxoplasmosis, Chaga’s disease and African trypanosomiasis caused by the Plasmodium, Leishmania, Toxoplasma and Trypanosoma genuses respectively; inflict a huge economic, health and social impact in endemic regions particularly tropical and sub-tropical regions. The combined infections are estimated at over a billion annually and approximately 1.1 million deaths annually. The global burden of the protozoan infections is worsened by the increased drug resistance, toxicity and the relatively high cost of treatment and prophylaxis. Therefore there has been a high demand for new drugs and drug targets that play a role in parasite virulence. Cysteine proteases have been validated as viable drug targets due to their role in the infectivity stage of the parasites within the human host. There is a variety of cysteine proteases hence they are subdivided into families and in this study we focus on the clan CA, papain family C1 proteases. The current inhibitors for the protozoan cysteine proteases lack selectivity and specificity which contributes to drug toxicity. Therefore there is a need to identify the differences and similarities between the host, vector and protozoan proteases. This study uses a variety of bioinformatics tools to assess these differences and similarities. The Plasmodium cysteine protease FP-2 is the most characterized protease hence it was used as a reference to all the other proteases and its homologs were retrieved, aligned and the evolutionary relationships established. The homologs were also analysed for common motifs and the physicochemical properties determined which were validated using the Kruskal-Wallis test. These analyses revealed that the host and vector cathepsins share similar properties while the parasite cathepsins differ. At sub-site level sub-site 2 showed greater variations suggesting diverse ligand specificity within the proteases, a revelation that is vital in the design of antiprotozoan inhibitors.
- Full Text:
- Date Issued: 2015
SA Jazz pianist dies
- Unknown
- Authors: Unknown
- Subjects: McGregor, Chris--1936-1990 , Brotherhood of Breath (Musical group) , Jazz
- Language: English
- Type: Article
- Identifier: vital:13738 , http://hdl.handle.net/10962/d1012752
- Description: Photocopied article from a South African newspaper about Chris McGregor's death.
- Full Text:
- Authors: Unknown
- Subjects: McGregor, Chris--1936-1990 , Brotherhood of Breath (Musical group) , Jazz
- Language: English
- Type: Article
- Identifier: vital:13738 , http://hdl.handle.net/10962/d1012752
- Description: Photocopied article from a South African newspaper about Chris McGregor's death.
- Full Text:
Commerce powered by 'National culture'? : an assessment of "Wear Local" campaigns as tools for reinvigorating the textile and clothing industries in Ghana and South Africa
- Authors: Darku, Esther Naa Dodua
- Date: 2017
- Subjects: Textile industry -- Economic aspects -- Ghana Textile industry -- Economic aspects -- South Africa Sustainable development -- Ghana , Sustainable development -- South Africa
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10353/2172 , vital:27619
- Description: This study examines the use of ‘cultural’ imagery and messaging as a tool to revitalise crucial national industries. Specifically, it examines the use of Wear Local campaigns in Ghana and South Africa as strategies to rejuvenate their textile industries and to make them viable in an increasingly competitive global market. Conceptualising Wear Local campaigns as possessing both cultural and economic imperatives, this study highlights how both factors contribute to making products of Buy Local campaigns marketable by showing their importance as both cultural and economic products. Using a descriptive-evaluative design, the study adopted a triangulated research approach comprising a survey, key informant interviews and document analysis. Survey questionnaires were administered to a total sample of 308 respondents in Ghana and South Africa. The qualitative phase of the study involved 10 key informant interviews (comprising textile labour unions, clothing designers, and government officials in both countries) and document/documentary research. The quantitative data were analysed using descriptive and inferential statistics, while the qualitative data were analysed using interpretive approaches, such as content analysis. The results indicate significant uses of national cultural elements in the campaign messaging in both Ghana and South Africa, as well as notable differences in the ways in which these campaigns resonated with consumers in the two countries. For instance, cultural differences accounted for high popularity of the campaign in Ghana and low popularity in South Africa. Following from these findings, the study concludes that the discourse on Buy Local and Wear Local, and the use of national culture in commerce, must go beyond the question of efficacy to examine the conditions under which these campaigns can become an effective economic/market tool. The study makes an important contribution to the existing knowledge on national culture, national economy and globalisation.
- Full Text:
- Date Issued: 2017
- Authors: Darku, Esther Naa Dodua
- Date: 2017
- Subjects: Textile industry -- Economic aspects -- Ghana Textile industry -- Economic aspects -- South Africa Sustainable development -- Ghana , Sustainable development -- South Africa
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10353/2172 , vital:27619
- Description: This study examines the use of ‘cultural’ imagery and messaging as a tool to revitalise crucial national industries. Specifically, it examines the use of Wear Local campaigns in Ghana and South Africa as strategies to rejuvenate their textile industries and to make them viable in an increasingly competitive global market. Conceptualising Wear Local campaigns as possessing both cultural and economic imperatives, this study highlights how both factors contribute to making products of Buy Local campaigns marketable by showing their importance as both cultural and economic products. Using a descriptive-evaluative design, the study adopted a triangulated research approach comprising a survey, key informant interviews and document analysis. Survey questionnaires were administered to a total sample of 308 respondents in Ghana and South Africa. The qualitative phase of the study involved 10 key informant interviews (comprising textile labour unions, clothing designers, and government officials in both countries) and document/documentary research. The quantitative data were analysed using descriptive and inferential statistics, while the qualitative data were analysed using interpretive approaches, such as content analysis. The results indicate significant uses of national cultural elements in the campaign messaging in both Ghana and South Africa, as well as notable differences in the ways in which these campaigns resonated with consumers in the two countries. For instance, cultural differences accounted for high popularity of the campaign in Ghana and low popularity in South Africa. Following from these findings, the study concludes that the discourse on Buy Local and Wear Local, and the use of national culture in commerce, must go beyond the question of efficacy to examine the conditions under which these campaigns can become an effective economic/market tool. The study makes an important contribution to the existing knowledge on national culture, national economy and globalisation.
- Full Text:
- Date Issued: 2017
Rhodes 1985 - 95
- Authors: Henderson, Derek Scott
- Date: 1985
- Language: English
- Type: text
- Identifier: vital:7505 , http://hdl.handle.net/10962/d1018382
- Full Text:
- Date Issued: 1985
- Authors: Henderson, Derek Scott
- Date: 1985
- Language: English
- Type: text
- Identifier: vital:7505 , http://hdl.handle.net/10962/d1018382
- Full Text:
- Date Issued: 1985
Understanding the harm of rape
- Authors: Kelland, Lindsay-Ann
- Date: 2013-04-19
- Subjects: Rape -- Social aspects--Research -- South Africa Rape -- Psychological aspects -- Research -- South Africa Rape trauma syndrome -- Research -- South Africa Rape victims -- South Africa Patriarchy -- South Africa Sexual dominance and submission -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:2700 , http://hdl.handle.net/10962/d1001582
- Description: The aims of this thesis are twofold: to provide an account of the lived experience of the harm of male-on-female rape in patriarchal societies and, on the basis of this account, to generate suggestions that could be of use in the recovery process for survivors of this type of rape. In order to reach these aims my thesis is divided into three parts. In the first part, I propose a phenomenologically based account of women’s situation as a group under patriarchy, according to which women as a group are subjugated to the hegemonic rule of patriarchal ideology. I argue, further, that the meaning, place and pervasiveness of sexual objectification in the lives of women under patriarchy typically results in women’s alienation from their bodies and creates an atmosphere of threat under which women qua women are especially vulnerable to rape. In the second part, I explore the lived experience of the harm of rape; focusing, first, on the reflexive process whereby a survivor attempts to understand how she has been harmed and, second, on providing explanations based on shared features in the lives of women for two phenomena reported to be experienced by rape victims in the aftermath of the trauma, which I call ‘shattering’ and ‘fragmentation'. My discussion of the lived experience of the harm of rape is meant to supplement existing accounts in the contemporary literature that, I argue, are limited to a thirdperson, objective point of view and so fail to provide a link between the harms they describe and the victim’s actual experience of these harms. Finally, I defend two suggestions for the building up of the survivor’s agency and personhood in the aftermath of rape—the deliberate therapeutic use of feminist consciousness-raising and the use of narrative understanding. , Adobe Acrobat 9.53 Paper Capture Plug-in
- Full Text:
- Authors: Kelland, Lindsay-Ann
- Date: 2013-04-19
- Subjects: Rape -- Social aspects--Research -- South Africa Rape -- Psychological aspects -- Research -- South Africa Rape trauma syndrome -- Research -- South Africa Rape victims -- South Africa Patriarchy -- South Africa Sexual dominance and submission -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:2700 , http://hdl.handle.net/10962/d1001582
- Description: The aims of this thesis are twofold: to provide an account of the lived experience of the harm of male-on-female rape in patriarchal societies and, on the basis of this account, to generate suggestions that could be of use in the recovery process for survivors of this type of rape. In order to reach these aims my thesis is divided into three parts. In the first part, I propose a phenomenologically based account of women’s situation as a group under patriarchy, according to which women as a group are subjugated to the hegemonic rule of patriarchal ideology. I argue, further, that the meaning, place and pervasiveness of sexual objectification in the lives of women under patriarchy typically results in women’s alienation from their bodies and creates an atmosphere of threat under which women qua women are especially vulnerable to rape. In the second part, I explore the lived experience of the harm of rape; focusing, first, on the reflexive process whereby a survivor attempts to understand how she has been harmed and, second, on providing explanations based on shared features in the lives of women for two phenomena reported to be experienced by rape victims in the aftermath of the trauma, which I call ‘shattering’ and ‘fragmentation'. My discussion of the lived experience of the harm of rape is meant to supplement existing accounts in the contemporary literature that, I argue, are limited to a thirdperson, objective point of view and so fail to provide a link between the harms they describe and the victim’s actual experience of these harms. Finally, I defend two suggestions for the building up of the survivor’s agency and personhood in the aftermath of rape—the deliberate therapeutic use of feminist consciousness-raising and the use of narrative understanding. , Adobe Acrobat 9.53 Paper Capture Plug-in
- Full Text:
Remora : implementing adaptive parallelism on a heterogeneous cluster of networked workstations
- Authors: Rehmet, Geoffrey Michael
- Date: 1995
- Subjects: LINDA (Computer system) , Local area networks (Computer networks) , Computer networks , Remora (Computer system)
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4673 , http://hdl.handle.net/10962/d1006696 , LINDA (Computer system) , Local area networks (Computer networks) , Computer networks , Remora (Computer system)
- Description: Computers connected to a local area network are often only fully utilized for short periods of time. In fact, most workstations are not used at all for a significant portion of the day. The combined "idle time" of the workstations on a network constitutes a significant computing resource, which is generally wasted. If harnessed properly, such a resource could constitute a cheap alternative to expensive high-performance computers. Adaptive parallelism refers to the parallel execution of a computation on a dynamically changing set of processors. This thesis investigates the viability of this approach as a vehicle to harness the "idle cycles" available on a heterogeneous cluster of networked computers. A system, called Remora, which implements adaptive parallelism via the Linda programming paradigm, is presented. Experiments, performed using Remora, show that adaptive parallelism provides an efficient vehicle for using idle processor cycles, without having an adverse effect on the tasks which constitute the normal workload of the computers being used.
- Full Text:
- Date Issued: 1995
- Authors: Rehmet, Geoffrey Michael
- Date: 1995
- Subjects: LINDA (Computer system) , Local area networks (Computer networks) , Computer networks , Remora (Computer system)
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4673 , http://hdl.handle.net/10962/d1006696 , LINDA (Computer system) , Local area networks (Computer networks) , Computer networks , Remora (Computer system)
- Description: Computers connected to a local area network are often only fully utilized for short periods of time. In fact, most workstations are not used at all for a significant portion of the day. The combined "idle time" of the workstations on a network constitutes a significant computing resource, which is generally wasted. If harnessed properly, such a resource could constitute a cheap alternative to expensive high-performance computers. Adaptive parallelism refers to the parallel execution of a computation on a dynamically changing set of processors. This thesis investigates the viability of this approach as a vehicle to harness the "idle cycles" available on a heterogeneous cluster of networked computers. A system, called Remora, which implements adaptive parallelism via the Linda programming paradigm, is presented. Experiments, performed using Remora, show that adaptive parallelism provides an efficient vehicle for using idle processor cycles, without having an adverse effect on the tasks which constitute the normal workload of the computers being used.
- Full Text:
- Date Issued: 1995
A proxy approach to protocol interoperability within digital audio networks
- Authors: Igumbor, Osedum Peter
- Date: 2010
- Subjects: Digital communications , Local area networks (Computer networks) , Computer sound processing , Computer networks , Computer network protocols
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4601 , http://hdl.handle.net/10962/d1004852 , Digital communications , Local area networks (Computer networks) , Computer sound processing , Computer networks , Computer network protocols
- Description: Digital audio networks are becoming the preferred solution for the interconnection of professional audio devices. Prominent amongst their advantages are: reduced noise interference, signal multiplexing, and a reduction in the number of cables connecting networked devices. In the context of professional audio, digital networks have been used to connect devices including: mixers, effects units, preamplifiers, breakout boxes, computers, monitoring controllers, and synthesizers. Such networks are governed by protocols that define the connection management rocedures, and device synchronization processes of devices that conform to the protocols. A wide range of digital audio network control protocols exist, each defining specific hardware requirements of devices that conform to them. Device parameter control is achieved by sending a protocol message that indicates the target parameter, and the action that should be performed on the parameter. Typically, a device will conform to only one protocol. By implication, only devices that conform to a specific protocol can communicate with each other, and only a controller that conforms to the protocol can control such devices. This results in the isolation of devices that conform to disparate protocols, since devices of different protocols cannot communicate with each other. This is currently a challenge in the professional music industry, particularly where digital networks are used for audio device control. This investigation seeks to resolve the issue of interoperability between professional audio devices that conform to different digital audio network protocols. This thesis proposes the use of a proxy that allows for the translation of protocol messages, as a solution to the interoperability problem. The proxy abstracts devices of one protocol in terms of another, hence allowing all the networked devices to appear as conforming to the same protocol. The proxy receives messages on behalf of the abstracted device, and then fulfills them in accordance with the protocol that the abstracted device conforms to. Any number of protocol devices can be abstracted within such a proxy. This has the added advantage of allowing a common controller to control devices that conform to the different protocols.
- Full Text:
- Date Issued: 2010
- Authors: Igumbor, Osedum Peter
- Date: 2010
- Subjects: Digital communications , Local area networks (Computer networks) , Computer sound processing , Computer networks , Computer network protocols
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4601 , http://hdl.handle.net/10962/d1004852 , Digital communications , Local area networks (Computer networks) , Computer sound processing , Computer networks , Computer network protocols
- Description: Digital audio networks are becoming the preferred solution for the interconnection of professional audio devices. Prominent amongst their advantages are: reduced noise interference, signal multiplexing, and a reduction in the number of cables connecting networked devices. In the context of professional audio, digital networks have been used to connect devices including: mixers, effects units, preamplifiers, breakout boxes, computers, monitoring controllers, and synthesizers. Such networks are governed by protocols that define the connection management rocedures, and device synchronization processes of devices that conform to the protocols. A wide range of digital audio network control protocols exist, each defining specific hardware requirements of devices that conform to them. Device parameter control is achieved by sending a protocol message that indicates the target parameter, and the action that should be performed on the parameter. Typically, a device will conform to only one protocol. By implication, only devices that conform to a specific protocol can communicate with each other, and only a controller that conforms to the protocol can control such devices. This results in the isolation of devices that conform to disparate protocols, since devices of different protocols cannot communicate with each other. This is currently a challenge in the professional music industry, particularly where digital networks are used for audio device control. This investigation seeks to resolve the issue of interoperability between professional audio devices that conform to different digital audio network protocols. This thesis proposes the use of a proxy that allows for the translation of protocol messages, as a solution to the interoperability problem. The proxy abstracts devices of one protocol in terms of another, hence allowing all the networked devices to appear as conforming to the same protocol. The proxy receives messages on behalf of the abstracted device, and then fulfills them in accordance with the protocol that the abstracted device conforms to. Any number of protocol devices can be abstracted within such a proxy. This has the added advantage of allowing a common controller to control devices that conform to the different protocols.
- Full Text:
- Date Issued: 2010
Evaluating social media participation for successful marketing and communication by selected private game reserves, Eastern Cape, South Africa
- Authors: Booth, Tara
- Date: 2013
- Subjects: Social media -- Economic aspects , Online social networks -- Economic aspects , Game reserves -- South Africa -- Eastern Cape -- Marketing , Internet marketing -- Economic aspects , Social media -- Marketing , Tourism -- Marketing , Communication in management
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:843 , http://hdl.handle.net/10962/d1015692
- Description: Social media has become one of the defining features of the technological advances known as Web 2.0. As social media has increased in popularity, so businesses are expected to participate. Social media platforms enable businesses to widely broadcast a message as well as interact directly with individual customers. Customers are also able to interact directly with one another and share information and reviews about products and services offered. This suits the tourism industry particularly well. Internationally, research has shown that individuals use social media and other online tools to research potential holiday destinations. In addition social media is used during travel to share snapshots and commentary as well as after travel, through reviews and recommendations on platforms such as TripAdvisor. However, few studies have investigated how tourism destinations use social media to attract new clients and retain existing clients. Very little research has been done on tourism and social media in South Africa despite the importance of this industry to Gross Domestic Product (GDP). This study focused on four-star establishments within the photographic wildlife tourism industry in the Eastern Cape of South Africa. An initial survey of social media participation was carried out within the framework set out by Chan and Guillet (2011); this was then followed up with interviews with selected managers. Results showed that, in general, Private Game Reserves (PGRs) had embraced social media as a communication and marketing platform; despite concerns raised about the lack of control over content as well as poor understanding of the influence social media might have on the bottom line. TripAdvisor, Facebook and Twitter were the most commonly used platforms due to management familiarity with the platform and their ease of use. Few lodges utilised blogs or content sites such as YouTube and management cited time commitments associated with this type of platform as a reason for non-participation. However, although most PGRs or lodges had a profile on social media, this did not always mean active participation. Frequently, lodges began updating but gradually stopped after a few months. It was noted however that only one of the lodges interviewed retained an individual whose sole responsibility was social media; generally lodges did not feel that a dedicated person was necessary. This may result in a lack of time available on the part of the individual responsible or simply be a case of not understanding the platform or how to use it effectively. However, none of the PGRs with poor social media participation responded to interview requests and therefore it was not possible to determine the reasons for their poor participation. Among those lodges that actively participated, most succeed in retaining fans and followers through consistent posting of relevant and interesting content as well as customised responses that encouraged fans or followers’ interaction. However, there did not appear to be any evidence of using social media to learn about fans and followers in order to better customise the lodge offerings. This may not be necessary in this type of industry as PGRs sell a specific product and have a limited ability to customise offerings. In addition, there may be other sources of market information which lodges prefer to use. Special offers, competitions and promotions had limited success on social media. Generally, lodges used social media to promote links to a dedicated competition or promotions page. In conclusion, the managers interviewed felt strongly that social media had made a measureable impact on the tourism industry and was a channel that was here to stay. Further research around the best practice and most effective use will enable PGRs to develop and maintain effective strategies for social media participation.
- Full Text:
- Date Issued: 2013
- Authors: Booth, Tara
- Date: 2013
- Subjects: Social media -- Economic aspects , Online social networks -- Economic aspects , Game reserves -- South Africa -- Eastern Cape -- Marketing , Internet marketing -- Economic aspects , Social media -- Marketing , Tourism -- Marketing , Communication in management
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:843 , http://hdl.handle.net/10962/d1015692
- Description: Social media has become one of the defining features of the technological advances known as Web 2.0. As social media has increased in popularity, so businesses are expected to participate. Social media platforms enable businesses to widely broadcast a message as well as interact directly with individual customers. Customers are also able to interact directly with one another and share information and reviews about products and services offered. This suits the tourism industry particularly well. Internationally, research has shown that individuals use social media and other online tools to research potential holiday destinations. In addition social media is used during travel to share snapshots and commentary as well as after travel, through reviews and recommendations on platforms such as TripAdvisor. However, few studies have investigated how tourism destinations use social media to attract new clients and retain existing clients. Very little research has been done on tourism and social media in South Africa despite the importance of this industry to Gross Domestic Product (GDP). This study focused on four-star establishments within the photographic wildlife tourism industry in the Eastern Cape of South Africa. An initial survey of social media participation was carried out within the framework set out by Chan and Guillet (2011); this was then followed up with interviews with selected managers. Results showed that, in general, Private Game Reserves (PGRs) had embraced social media as a communication and marketing platform; despite concerns raised about the lack of control over content as well as poor understanding of the influence social media might have on the bottom line. TripAdvisor, Facebook and Twitter were the most commonly used platforms due to management familiarity with the platform and their ease of use. Few lodges utilised blogs or content sites such as YouTube and management cited time commitments associated with this type of platform as a reason for non-participation. However, although most PGRs or lodges had a profile on social media, this did not always mean active participation. Frequently, lodges began updating but gradually stopped after a few months. It was noted however that only one of the lodges interviewed retained an individual whose sole responsibility was social media; generally lodges did not feel that a dedicated person was necessary. This may result in a lack of time available on the part of the individual responsible or simply be a case of not understanding the platform or how to use it effectively. However, none of the PGRs with poor social media participation responded to interview requests and therefore it was not possible to determine the reasons for their poor participation. Among those lodges that actively participated, most succeed in retaining fans and followers through consistent posting of relevant and interesting content as well as customised responses that encouraged fans or followers’ interaction. However, there did not appear to be any evidence of using social media to learn about fans and followers in order to better customise the lodge offerings. This may not be necessary in this type of industry as PGRs sell a specific product and have a limited ability to customise offerings. In addition, there may be other sources of market information which lodges prefer to use. Special offers, competitions and promotions had limited success on social media. Generally, lodges used social media to promote links to a dedicated competition or promotions page. In conclusion, the managers interviewed felt strongly that social media had made a measureable impact on the tourism industry and was a channel that was here to stay. Further research around the best practice and most effective use will enable PGRs to develop and maintain effective strategies for social media participation.
- Full Text:
- Date Issued: 2013
Surface patterning using scanning electrochemical microscopy to locally trigger a “click” chemistry reaction
- Quinton, Damien, Maringa, Audacity, Griveau, Sophie, Nyokong, Tebello, Bedioui, Fethi
- Authors: Quinton, Damien , Maringa, Audacity , Griveau, Sophie , Nyokong, Tebello , Bedioui, Fethi
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/241805 , vital:50971 , xlink:href="https://doi.org/10.1016/j.elecom.2013.03.021"
- Description: We report on the surface micropatterning of conductive surfaces via the electrochemical triggering of a click reaction, the copper(I) catalyzed azide–alkyne cycloaddition reaction (CuAAC) by SECM via a two-step approach: (i) functionalization on the entire surface with azido-aryl groups by using the diazonium approach followed by (ii) the covalent linkage of alkyne-bearing ferrocene by CuAAC within a local area by SECM. More precisely, the click reaction was triggered by Cu(I) catalyst generation for 30 min at the SECM tip positioned ≈ 10 μm above the azido-aryl modified surface. The dimension of the spot obtained under these conditions was ≈ 75 μm. The electrochemical imaging by SECM of the ultra thin area locally clicked with ferrocene moieties was made thanks to the electrocatalytic properties of the ferrocene modified surface towards ferrocyanide electrooxidation. This local clicking procedure opens the gate to further controlled functionalization of restricted small substrates.
- Full Text:
- Date Issued: 2013
- Authors: Quinton, Damien , Maringa, Audacity , Griveau, Sophie , Nyokong, Tebello , Bedioui, Fethi
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/241805 , vital:50971 , xlink:href="https://doi.org/10.1016/j.elecom.2013.03.021"
- Description: We report on the surface micropatterning of conductive surfaces via the electrochemical triggering of a click reaction, the copper(I) catalyzed azide–alkyne cycloaddition reaction (CuAAC) by SECM via a two-step approach: (i) functionalization on the entire surface with azido-aryl groups by using the diazonium approach followed by (ii) the covalent linkage of alkyne-bearing ferrocene by CuAAC within a local area by SECM. More precisely, the click reaction was triggered by Cu(I) catalyst generation for 30 min at the SECM tip positioned ≈ 10 μm above the azido-aryl modified surface. The dimension of the spot obtained under these conditions was ≈ 75 μm. The electrochemical imaging by SECM of the ultra thin area locally clicked with ferrocene moieties was made thanks to the electrocatalytic properties of the ferrocene modified surface towards ferrocyanide electrooxidation. This local clicking procedure opens the gate to further controlled functionalization of restricted small substrates.
- Full Text:
- Date Issued: 2013
Eliciting and combining expert opinion : an overview and comparison of methods
- Authors: Chinyamakobvu, Mutsa Carole
- Date: 2015
- Subjects: Decision making -- Statistical methods , Expertise , Bayesian statistical decision theory , Statistical decision , Delphi method , Paired comparisons (Statistics)
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5579 , http://hdl.handle.net/10962/d1017827
- Description: Decision makers have long relied on experts to inform their decision making. Expert judgment analysis is a way to elicit and combine the opinions of a group of experts to facilitate decision making. The use of expert judgment is most appropriate when there is a lack of data for obtaining reasonable statistical results. The experts are asked for advice by one or more decision makers who face a specific real decision problem. The decision makers are outside the group of experts and are jointly responsible and accountable for the decision and committed to finding solutions that everyone can live with. The emphasis is on the decision makers learning from the experts. The focus of this thesis is an overview and comparison of the various elicitation and combination methods available. These include the traditional committee method, the Delphi method, the paired comparisons method, the negative exponential model, Cooke’s classical model, the histogram technique, using the Dirichlet distribution in the case of a set of uncertain proportions which must sum to one, and the employment of overfitting. The supra Bayes approach, the determination of weights for the experts, and combining the opinions of experts where each opinion is associated with a confidence level that represents the expert’s conviction of his own judgment are also considered.
- Full Text:
- Date Issued: 2015
- Authors: Chinyamakobvu, Mutsa Carole
- Date: 2015
- Subjects: Decision making -- Statistical methods , Expertise , Bayesian statistical decision theory , Statistical decision , Delphi method , Paired comparisons (Statistics)
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5579 , http://hdl.handle.net/10962/d1017827
- Description: Decision makers have long relied on experts to inform their decision making. Expert judgment analysis is a way to elicit and combine the opinions of a group of experts to facilitate decision making. The use of expert judgment is most appropriate when there is a lack of data for obtaining reasonable statistical results. The experts are asked for advice by one or more decision makers who face a specific real decision problem. The decision makers are outside the group of experts and are jointly responsible and accountable for the decision and committed to finding solutions that everyone can live with. The emphasis is on the decision makers learning from the experts. The focus of this thesis is an overview and comparison of the various elicitation and combination methods available. These include the traditional committee method, the Delphi method, the paired comparisons method, the negative exponential model, Cooke’s classical model, the histogram technique, using the Dirichlet distribution in the case of a set of uncertain proportions which must sum to one, and the employment of overfitting. The supra Bayes approach, the determination of weights for the experts, and combining the opinions of experts where each opinion is associated with a confidence level that represents the expert’s conviction of his own judgment are also considered.
- Full Text:
- Date Issued: 2015
Mellon Foundation Programme for Accelerated Development Orientaiton Workshop welcome.
- Authors: Badat, Saleem
- Date: 2007-02-08 , 2014-07-14
- Language: English
- Type: Text
- Identifier: vital:7637 , http://hdl.handle.net/10962/d1012615
- Full Text:
- Date Issued: 2007-02-08
- Authors: Badat, Saleem
- Date: 2007-02-08 , 2014-07-14
- Language: English
- Type: Text
- Identifier: vital:7637 , http://hdl.handle.net/10962/d1012615
- Full Text:
- Date Issued: 2007-02-08
Life history changes of two reef fish species in exploited and unexploited marine environments in South Africa
- Authors: Buxton, Colin David
- Date: 1988
- Subjects: Reef fishes -- Africa, Southern Chrysoblephus laticeps Chrysoblephus cristiceps
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5189 , http://hdl.handle.net/10962/d1001965
- Description: A detailed investigation into the life histories of Chrysoblephus laticeps and c. cristiceps in exploited and unexploited marine environments on the south-east coast of southern Africa is presented. The study provided information necessary for the evaluation of marine reserves as a management option for these and similar reef species. Visual underwater assessments showed a clear spatial separation between adults and juveniles of both species, suggesting a recruitment of juveniles into shallow water followed by a gradual outward migration into deeper water with age. Denslty estlmates of C. laticeps in the Noordhoek (0.0064 fish/m²) and Tsitslkamma (0.0254 fish/m²) areas were significantly different and were attributed to exploitation. Within area differences in density were also significantly correlated with temperature) depth and substratum relief. Similar comparisons for C. cristiceps were not possible because these fish shied away from divers. Habitat preferences were mirrored in the diets of both species which fed on a wide variety of reef associated benthic animals. Size of prey appeared to be gape limited, only larger fish being able to manipulate prey. Quantitative differences between the diets of fish sampled in different areas were a reflection of differences in available prey and not related to the relative density of predators. The dietary characteristics recorded in these fish were typical of search hunters. An age and growth study based on the examination of sectioned otoliths showed that both species were slow growing and long lived. Maximum recorded ages were 18 and 22 years for C. laticeps and C. cristiceps respectively. Growth rates in exploited and unexploited areas were not significantly different although there was an indication that growth was slower in the exploited areas for C. cristiceps. Several inconsistencies in otolith interpretation and terminology were evaluated. Contrary to other South African studies the results suggested that somatic growth was fastest just after spawning. This coincided with the winter months and was reflected by the deposition of a hyaline zone in the otolith. Two independent estimates, the Pauli derivation and visually assessed length frequency analysis, produced the same value for total mortality of C. laticeps in the Tsitsikamma area (0.2). This result, together with a significant difference in the rate of fishing mortality at different areas along the coast suggested that the populations sampled were discrete and supported the postulate that both species were sedentary. Further support was obtained from a mark-recapture study. Although sample numbers were low the results showed no evidence of large scale migratory patterns in these fish. An investigation of the reproductive biology of both fish showed that they were protogynous hermaphrodites, all males being derived from females with no evidence for polyandry. Males were shown to be capable of mating with a number of females and this, together with monandry, monochromatism and a small testis size, suggested a polygynous mating system in both species. Observations of the courtship behaviour in captive c. laticeps also supported polygyny. A significant difference in the mean size at sex reversal between unexploited and exploited populations supported the postulate that sex reversal was independent of the size or age of the animal. The size at which sex reversal occurred appeared to be dependent on sex ratio. A detailed yield per recruit analysis of the response of the population to different levels of fishing mortality and size at recruitment (t [subscript]r), showed that sex reversing species were particularly vulnerable to over fishing. This was due to a dramatic decline in the number of surviving individuals past t[subscript]r which resulted in a skewing of the sex ratio towards females. Evidence is presented to show that current legislation is inadequately protecting the spawner stock of both species. In conclusion it is shown that longevity, sex reversal, restricted movements and the occupation of a demersal habitat make these species particularly vulnerable to over exploitation in a size- selective fishery. The sustained yield in the linefishery is suggested to be a result of distant recruitment from relatively unexploited populations rather than the adequacy of current conservation measures. The need to protect the spawner stock is emphasised and the use of marine reserves as an additional protection for sedentary reef-dwelling species is therefore advocated.
- Full Text:
- Date Issued: 1988
- Authors: Buxton, Colin David
- Date: 1988
- Subjects: Reef fishes -- Africa, Southern Chrysoblephus laticeps Chrysoblephus cristiceps
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5189 , http://hdl.handle.net/10962/d1001965
- Description: A detailed investigation into the life histories of Chrysoblephus laticeps and c. cristiceps in exploited and unexploited marine environments on the south-east coast of southern Africa is presented. The study provided information necessary for the evaluation of marine reserves as a management option for these and similar reef species. Visual underwater assessments showed a clear spatial separation between adults and juveniles of both species, suggesting a recruitment of juveniles into shallow water followed by a gradual outward migration into deeper water with age. Denslty estlmates of C. laticeps in the Noordhoek (0.0064 fish/m²) and Tsitslkamma (0.0254 fish/m²) areas were significantly different and were attributed to exploitation. Within area differences in density were also significantly correlated with temperature) depth and substratum relief. Similar comparisons for C. cristiceps were not possible because these fish shied away from divers. Habitat preferences were mirrored in the diets of both species which fed on a wide variety of reef associated benthic animals. Size of prey appeared to be gape limited, only larger fish being able to manipulate prey. Quantitative differences between the diets of fish sampled in different areas were a reflection of differences in available prey and not related to the relative density of predators. The dietary characteristics recorded in these fish were typical of search hunters. An age and growth study based on the examination of sectioned otoliths showed that both species were slow growing and long lived. Maximum recorded ages were 18 and 22 years for C. laticeps and C. cristiceps respectively. Growth rates in exploited and unexploited areas were not significantly different although there was an indication that growth was slower in the exploited areas for C. cristiceps. Several inconsistencies in otolith interpretation and terminology were evaluated. Contrary to other South African studies the results suggested that somatic growth was fastest just after spawning. This coincided with the winter months and was reflected by the deposition of a hyaline zone in the otolith. Two independent estimates, the Pauli derivation and visually assessed length frequency analysis, produced the same value for total mortality of C. laticeps in the Tsitsikamma area (0.2). This result, together with a significant difference in the rate of fishing mortality at different areas along the coast suggested that the populations sampled were discrete and supported the postulate that both species were sedentary. Further support was obtained from a mark-recapture study. Although sample numbers were low the results showed no evidence of large scale migratory patterns in these fish. An investigation of the reproductive biology of both fish showed that they were protogynous hermaphrodites, all males being derived from females with no evidence for polyandry. Males were shown to be capable of mating with a number of females and this, together with monandry, monochromatism and a small testis size, suggested a polygynous mating system in both species. Observations of the courtship behaviour in captive c. laticeps also supported polygyny. A significant difference in the mean size at sex reversal between unexploited and exploited populations supported the postulate that sex reversal was independent of the size or age of the animal. The size at which sex reversal occurred appeared to be dependent on sex ratio. A detailed yield per recruit analysis of the response of the population to different levels of fishing mortality and size at recruitment (t [subscript]r), showed that sex reversing species were particularly vulnerable to over fishing. This was due to a dramatic decline in the number of surviving individuals past t[subscript]r which resulted in a skewing of the sex ratio towards females. Evidence is presented to show that current legislation is inadequately protecting the spawner stock of both species. In conclusion it is shown that longevity, sex reversal, restricted movements and the occupation of a demersal habitat make these species particularly vulnerable to over exploitation in a size- selective fishery. The sustained yield in the linefishery is suggested to be a result of distant recruitment from relatively unexploited populations rather than the adequacy of current conservation measures. The need to protect the spawner stock is emphasised and the use of marine reserves as an additional protection for sedentary reef-dwelling species is therefore advocated.
- Full Text:
- Date Issued: 1988
Shifting Norms and Practices of International Criminal Justice: Exploring African State and Non-State Agency at the International Criminal Court
- Authors: Mtero, Shingirai
- Date: 2021-10-29
- Subjects: Uncatalogued
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/192875 , vital:45273
- Description: Thesis (PhD) -- Faculty of Humanities, Political and International Studies, 2021
- Full Text:
- Date Issued: 2021-10-29
- Authors: Mtero, Shingirai
- Date: 2021-10-29
- Subjects: Uncatalogued
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/192875 , vital:45273
- Description: Thesis (PhD) -- Faculty of Humanities, Political and International Studies, 2021
- Full Text:
- Date Issued: 2021-10-29
The observation of extended sources with the Hartebeesthoek radio telescope
- Authors: Mountfort, Peter Ian
- Date: 1990
- Subjects: Radio telescopes
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5479 , http://hdl.handle.net/10962/d1005265
- Description: The Hartebeesthoek Radio Telescope is well suited to mapping large areas of sky at 2.3 GHz because of the stability and sensitivity of the noise-adding radiometer (Nicolson, 1970) and cryogenic amplifier used at this frequency, the relatively large 20' beam of the 26 m dish antenna, and its high-speed drive capability. Telescope control programs were written for the Observatory's online computer for automated mapping. Effort centred on removing the curved baseline or 'background' from each Declination (Dec) scan, due to atmospheric and ground radiation contributions varying as the antenna is scanned. Initially these backgrounds were measured over a wide range of Hour Angle (HA) for the Dec range of a map, and an interpolated curve subtracted from each on-source scan for its HA. A common base level was established by comparison with drift scans (observed with the antenna stationary). These different observations (on- and off-source Dec scans and drift scans) were combined into one in the Skymap system by performing Dec scans at a fixed starting HA for a period long enough to permit 'cold sky' and the source to drift through. A background formed by fitting a smooth curve through the lowest sample at each Dec provides a consistent relative base level for all the scans in an observation. A high scanning speed is used so that observations may fruitfully be repeated three times and interleaved to build a reliable, fully sampled map. As each observation has its own background removed, it may be made at any HA. For comparison, maps of Upper Scorpio produced by the earlier method (Baart et al., 1980) and the Magellanic Cloud region produced by Skymap (Mountfort et al., 1987) are shown. Skymap provides a simple and flexible mapping method which relies on the stability of the noise-adding radiometer and high-speed repeated scans to produce good maps of large or small extent with little computation. Correction for drift is more difficult than with systems which use intersecting scans, such as the 'nodding' scans used by Haslam et al. (1981) or the Azimuth scans of Reich (1982).
- Full Text:
- Date Issued: 1990
- Authors: Mountfort, Peter Ian
- Date: 1990
- Subjects: Radio telescopes
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5479 , http://hdl.handle.net/10962/d1005265
- Description: The Hartebeesthoek Radio Telescope is well suited to mapping large areas of sky at 2.3 GHz because of the stability and sensitivity of the noise-adding radiometer (Nicolson, 1970) and cryogenic amplifier used at this frequency, the relatively large 20' beam of the 26 m dish antenna, and its high-speed drive capability. Telescope control programs were written for the Observatory's online computer for automated mapping. Effort centred on removing the curved baseline or 'background' from each Declination (Dec) scan, due to atmospheric and ground radiation contributions varying as the antenna is scanned. Initially these backgrounds were measured over a wide range of Hour Angle (HA) for the Dec range of a map, and an interpolated curve subtracted from each on-source scan for its HA. A common base level was established by comparison with drift scans (observed with the antenna stationary). These different observations (on- and off-source Dec scans and drift scans) were combined into one in the Skymap system by performing Dec scans at a fixed starting HA for a period long enough to permit 'cold sky' and the source to drift through. A background formed by fitting a smooth curve through the lowest sample at each Dec provides a consistent relative base level for all the scans in an observation. A high scanning speed is used so that observations may fruitfully be repeated three times and interleaved to build a reliable, fully sampled map. As each observation has its own background removed, it may be made at any HA. For comparison, maps of Upper Scorpio produced by the earlier method (Baart et al., 1980) and the Magellanic Cloud region produced by Skymap (Mountfort et al., 1987) are shown. Skymap provides a simple and flexible mapping method which relies on the stability of the noise-adding radiometer and high-speed repeated scans to produce good maps of large or small extent with little computation. Correction for drift is more difficult than with systems which use intersecting scans, such as the 'nodding' scans used by Haslam et al. (1981) or the Azimuth scans of Reich (1982).
- Full Text:
- Date Issued: 1990
Enhancing military efficiency : a South African perspective
- Christie, Candice J, Todd, Andrew I
- Authors: Christie, Candice J , Todd, Andrew I
- Date: 2001
- Language: English
- Type: Article
- Identifier: vital:6749 , http://hdl.handle.net/10962/d1009329
- Description: While extensive military research has been conducted in developed countries, very little work has been done on soldiers in industrially developing countries (IDCs). Although many aspects of marching are similar around the globe, the challenges facing soldiers in IDCs, and in particular South Africa, are unique. Since the 1990’s South Africa has seen a considerable shift in the morphological and cultural make-up of the South African National Defence Force (SANDF). The result is a mix of soldiers from a variety of ethnic backgrounds. Ethnic differences may ultimately impact performance particularly as research has postulated that Blacks and Whites may differ in body composition and body proportions. It is highly probable then that the universal recommendations of optimal marching speeds, load masses and gradients need to be modified to accommodate the diversity of soldiers which currently comprise the SANDF.
- Full Text:
- Date Issued: 2001
- Authors: Christie, Candice J , Todd, Andrew I
- Date: 2001
- Language: English
- Type: Article
- Identifier: vital:6749 , http://hdl.handle.net/10962/d1009329
- Description: While extensive military research has been conducted in developed countries, very little work has been done on soldiers in industrially developing countries (IDCs). Although many aspects of marching are similar around the globe, the challenges facing soldiers in IDCs, and in particular South Africa, are unique. Since the 1990’s South Africa has seen a considerable shift in the morphological and cultural make-up of the South African National Defence Force (SANDF). The result is a mix of soldiers from a variety of ethnic backgrounds. Ethnic differences may ultimately impact performance particularly as research has postulated that Blacks and Whites may differ in body composition and body proportions. It is highly probable then that the universal recommendations of optimal marching speeds, load masses and gradients need to be modified to accommodate the diversity of soldiers which currently comprise the SANDF.
- Full Text:
- Date Issued: 2001
Towards a threat assessment framework for consumer health wearables
- Authors: Mnjama, Javan Joshua
- Date: 2018
- Subjects: Activity trackers (Wearable technology) , Computer networks -- Security measures , Data protection , Information storage and retrieval systems -- Security systems , Computer security -- Software , Consumer Health Wearable Threat Assessment Framework , Design Science Research
- Language: English
- Type: text , Thesis , Masters , MCom
- Identifier: http://hdl.handle.net/10962/62649 , vital:28225
- Description: The collection of health data such as physical activity, consumption and physiological data through the use of consumer health wearables via fitness trackers are very beneficial for the promotion of physical wellness. However, consumer health wearables and their associated applications are known to have privacy and security concerns that can potentially make the collected personal health data vulnerable to hackers. These concerns are attributed to security theoretical frameworks not sufficiently addressing the entirety of privacy and security concerns relating to the diverse technological ecosystem of consumer health wearables. The objective of this research was therefore to develop a threat assessment framework that can be used to guide the detection of vulnerabilities which affect consumer health wearables and their associated applications. To meet this objective, the Design Science Research methodology was used to develop the desired artefact (Consumer Health Wearable Threat Assessment Framework). The framework is comprised of fourteen vulnerabilities classified according to Authentication, Authorization, Availability, Confidentiality, Non-Repudiation and Integrity. Through developing the artefact, the threat assessment framework was demonstrated on two fitness trackers and their associated applications. It was discovered, that the framework was able to identify how these vulnerabilities affected, these two test cases based on the classification categories of the framework. The framework was also evaluated by four security experts who assessed the quality, utility and efficacy of the framework. Experts, supported the use of the framework as a relevant and comprehensive framework to guide the detection of vulnerabilities towards consumer health wearables and their associated applications. The implication of this research study is that the framework can be used by developers to better identify the vulnerabilities of consumer health wearables and their associated applications. This will assist in creating a more securer environment for the storage and use of health data by consumer health wearables.
- Full Text:
- Date Issued: 2018
- Authors: Mnjama, Javan Joshua
- Date: 2018
- Subjects: Activity trackers (Wearable technology) , Computer networks -- Security measures , Data protection , Information storage and retrieval systems -- Security systems , Computer security -- Software , Consumer Health Wearable Threat Assessment Framework , Design Science Research
- Language: English
- Type: text , Thesis , Masters , MCom
- Identifier: http://hdl.handle.net/10962/62649 , vital:28225
- Description: The collection of health data such as physical activity, consumption and physiological data through the use of consumer health wearables via fitness trackers are very beneficial for the promotion of physical wellness. However, consumer health wearables and their associated applications are known to have privacy and security concerns that can potentially make the collected personal health data vulnerable to hackers. These concerns are attributed to security theoretical frameworks not sufficiently addressing the entirety of privacy and security concerns relating to the diverse technological ecosystem of consumer health wearables. The objective of this research was therefore to develop a threat assessment framework that can be used to guide the detection of vulnerabilities which affect consumer health wearables and their associated applications. To meet this objective, the Design Science Research methodology was used to develop the desired artefact (Consumer Health Wearable Threat Assessment Framework). The framework is comprised of fourteen vulnerabilities classified according to Authentication, Authorization, Availability, Confidentiality, Non-Repudiation and Integrity. Through developing the artefact, the threat assessment framework was demonstrated on two fitness trackers and their associated applications. It was discovered, that the framework was able to identify how these vulnerabilities affected, these two test cases based on the classification categories of the framework. The framework was also evaluated by four security experts who assessed the quality, utility and efficacy of the framework. Experts, supported the use of the framework as a relevant and comprehensive framework to guide the detection of vulnerabilities towards consumer health wearables and their associated applications. The implication of this research study is that the framework can be used by developers to better identify the vulnerabilities of consumer health wearables and their associated applications. This will assist in creating a more securer environment for the storage and use of health data by consumer health wearables.
- Full Text:
- Date Issued: 2018
The role of family structure and financial socialisation in influencing students' financial capabilities
- Authors: Antoni, Xolile Lucas
- Date: 2018
- Subjects: Finance, Personal , Families -- Economic aspects Finance -- Social aspects
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/21505 , vital:29531
- Description: This research used three theories to develop a theoretical framework that investigated the role of family structures and financial socialisation in influencing students’ levels of financial knowledge, attitudes, self-efficacy and behaviour (financial capabilities). It also examined the mediating role of family financial situation in the relationship between the family structure and the mechanisms of financial socialisation. The theories of consumer socialisation, family financial socialisation and family structure model, guided the development of a proposed theoretical framework and development of five major hypotheses. To answer the research questions of the study and test the hypotheses, this study followed a quantitative survey research design. Undergraduate students in the Faculty of Business and Economic Sciences completed 350 questionnaires. Using exploratory factor analyses results, the theoretical framework was updated, and statistical relationships tested. Simple regression analysis results showed that students who were born or raised in an intact family structure reported more financial socialisation in terms of the mechanisms of financial socialisation than students who were born or raised in non-intact family structures. Simple regression results showed that intact family structures had positive significant relationships with four of the six components of the mechanisms of financial socialisation. Furthermore, intact family structures had negative significant relationships with two components of the mechanisms of financial socialisation. Multiple regression results showed four components of the mechanisms of financial socialisation (teaching and monitoring, reinforcement of financial behaviour, modelling of financial behaviour and financial conflict) had positive significant relationships with financial capabilities. The components of financial socialisation agents (peers and media) had positive significant relationships with three components of financial capabilities (financial behaviour, money is respect and freedom, and money is good). In addition, family financial situation partially mediated the relationship between intact family structure and three components of the mechanisms of financial socialisation, namely, parental teaching and monitoring, modelling of financial behaviour and parental relationship. Furthermore, family financial situation perfectly mediated the relationship between intact family structures and one component of the mechanisms of financial socialisation (reinforcement of financial behaviour). Three components of the mechanisms of financial socialisation (parental teaching and monitoring, reinforcement of financial behaviour and modelling of financial behaviour) also perfectly mediated the relationship between intact family structure and one component of financial capabilities, namely, financial behaviour. Similarly, one component of the mechanisms of financial socialisation (parental teaching and monitoring) also perfectly mediated the relationship between intact family structure and one component of financial capabilities (financial self-efficacy). These results assisted in the development of a new empirically tested model to investigate the role of family structure and financial socialisation in influencing students’ financial capabilities. This study showed that family structures was an important variable that should not be excluded in financial planning as it influenced all the components of the mechanisms of financial socialisation. Financial socialisation agents also had an influence on financial capabilities and, thus, the parental financial socialisation should not be investigated in isolation. It was also important to identify the mechanisms of financial socialisation as seen in this study, as the components of the mechanisms had different influences on students’ financial capabilities. For this study, parental teaching and monitoring, reinforcement of financial behaviour and modelling of financial behaviour proved to be the most important components of the mechanisms of financial socialisation, which ultimately influenced students’ financial capabilities. This study has proved that family structures and financial socialisation influence the financial capabilities of students. To improve financial capabilities of students, parents should increase their level of modelling of financial behaviour and decrease the level of secrecy about money in the household. Parents should also instill positive financial attitudes in students, monitor their financial behaviour, and reinforce positive financial behaviour. This study contributes to the much-needed body of knowledge in financial planning by showing through empirical results that family structure has an influence on the components of the factor mechanisms of financial socialisation, and the factor financial capabilities. As little information exists to explain these relationships, this study makes a valuable contribution to new knowledge in this area.
- Full Text:
- Date Issued: 2018
- Authors: Antoni, Xolile Lucas
- Date: 2018
- Subjects: Finance, Personal , Families -- Economic aspects Finance -- Social aspects
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10948/21505 , vital:29531
- Description: This research used three theories to develop a theoretical framework that investigated the role of family structures and financial socialisation in influencing students’ levels of financial knowledge, attitudes, self-efficacy and behaviour (financial capabilities). It also examined the mediating role of family financial situation in the relationship between the family structure and the mechanisms of financial socialisation. The theories of consumer socialisation, family financial socialisation and family structure model, guided the development of a proposed theoretical framework and development of five major hypotheses. To answer the research questions of the study and test the hypotheses, this study followed a quantitative survey research design. Undergraduate students in the Faculty of Business and Economic Sciences completed 350 questionnaires. Using exploratory factor analyses results, the theoretical framework was updated, and statistical relationships tested. Simple regression analysis results showed that students who were born or raised in an intact family structure reported more financial socialisation in terms of the mechanisms of financial socialisation than students who were born or raised in non-intact family structures. Simple regression results showed that intact family structures had positive significant relationships with four of the six components of the mechanisms of financial socialisation. Furthermore, intact family structures had negative significant relationships with two components of the mechanisms of financial socialisation. Multiple regression results showed four components of the mechanisms of financial socialisation (teaching and monitoring, reinforcement of financial behaviour, modelling of financial behaviour and financial conflict) had positive significant relationships with financial capabilities. The components of financial socialisation agents (peers and media) had positive significant relationships with three components of financial capabilities (financial behaviour, money is respect and freedom, and money is good). In addition, family financial situation partially mediated the relationship between intact family structure and three components of the mechanisms of financial socialisation, namely, parental teaching and monitoring, modelling of financial behaviour and parental relationship. Furthermore, family financial situation perfectly mediated the relationship between intact family structures and one component of the mechanisms of financial socialisation (reinforcement of financial behaviour). Three components of the mechanisms of financial socialisation (parental teaching and monitoring, reinforcement of financial behaviour and modelling of financial behaviour) also perfectly mediated the relationship between intact family structure and one component of financial capabilities, namely, financial behaviour. Similarly, one component of the mechanisms of financial socialisation (parental teaching and monitoring) also perfectly mediated the relationship between intact family structure and one component of financial capabilities (financial self-efficacy). These results assisted in the development of a new empirically tested model to investigate the role of family structure and financial socialisation in influencing students’ financial capabilities. This study showed that family structures was an important variable that should not be excluded in financial planning as it influenced all the components of the mechanisms of financial socialisation. Financial socialisation agents also had an influence on financial capabilities and, thus, the parental financial socialisation should not be investigated in isolation. It was also important to identify the mechanisms of financial socialisation as seen in this study, as the components of the mechanisms had different influences on students’ financial capabilities. For this study, parental teaching and monitoring, reinforcement of financial behaviour and modelling of financial behaviour proved to be the most important components of the mechanisms of financial socialisation, which ultimately influenced students’ financial capabilities. This study has proved that family structures and financial socialisation influence the financial capabilities of students. To improve financial capabilities of students, parents should increase their level of modelling of financial behaviour and decrease the level of secrecy about money in the household. Parents should also instill positive financial attitudes in students, monitor their financial behaviour, and reinforce positive financial behaviour. This study contributes to the much-needed body of knowledge in financial planning by showing through empirical results that family structure has an influence on the components of the factor mechanisms of financial socialisation, and the factor financial capabilities. As little information exists to explain these relationships, this study makes a valuable contribution to new knowledge in this area.
- Full Text:
- Date Issued: 2018
Rhodeo, Vol. 20, No. 1
- Date: 1966-01-20
- Subjects: Grahamstown -- Newspapers , Journalism, Students -- South Africa , Rhodes University -- Activate , Rhodes University -- Students , Student newspapers and periodicals -- South Africa
- Language: English
- Type: Text
- Identifier: vital:14536 , http://hdl.handle.net/10962/d1019408 , Rhodeo original print version held at Cory Library for Humanities Research, Rhodes University
- Description: Rhodeo is the Independent Student Newspaper of Rhodes University. Located in Grahamstown, Rhodeo was established in 1947, and renamed in 1994 as Activate. During apartheid Rhodeo became an active part of the struggle for freedom of expression as part of the now defunct South African Student Press Union. Currently Activate is committed to informing Rhodes University students, staff and community members about relevant issues, mainly on campus. These issues range from hard news to more creative journalism. While Activate acts as a news source, one of its main objectives it to be accessible as a training ground for student journalists. The newspaper is run entirely by the students and is published twice a term. Activate is a free newspaper which receives an annual grant from the Rhodes University Student Representative Council, however, majority of its revenue is generated through advertising.
- Full Text:
- Date Issued: 1966-01-20
- Date: 1966-01-20
- Subjects: Grahamstown -- Newspapers , Journalism, Students -- South Africa , Rhodes University -- Activate , Rhodes University -- Students , Student newspapers and periodicals -- South Africa
- Language: English
- Type: Text
- Identifier: vital:14536 , http://hdl.handle.net/10962/d1019408 , Rhodeo original print version held at Cory Library for Humanities Research, Rhodes University
- Description: Rhodeo is the Independent Student Newspaper of Rhodes University. Located in Grahamstown, Rhodeo was established in 1947, and renamed in 1994 as Activate. During apartheid Rhodeo became an active part of the struggle for freedom of expression as part of the now defunct South African Student Press Union. Currently Activate is committed to informing Rhodes University students, staff and community members about relevant issues, mainly on campus. These issues range from hard news to more creative journalism. While Activate acts as a news source, one of its main objectives it to be accessible as a training ground for student journalists. The newspaper is run entirely by the students and is published twice a term. Activate is a free newspaper which receives an annual grant from the Rhodes University Student Representative Council, however, majority of its revenue is generated through advertising.
- Full Text:
- Date Issued: 1966-01-20