"Nested" cryptic diversity in a widespread marine ecosystem engineer: a challenge for detecting biological invasions
- Teske, Peter R, Ruis, Marc, McQuaid, Christopher D, Styan, Craig A, Piggott, Maxine P, Benhissoune, Saïd, Fuentes-Grünewald, Claudio, Walls, Kathy, Page, Mike, Attard, Catherine R M, Cooke, Georgina M, McClusky, Claire F, Banks, Sam C, Barker, Nigel P, Beheregaray, Luciano B
- Authors: Teske, Peter R , Ruis, Marc , McQuaid, Christopher D , Styan, Craig A , Piggott, Maxine P , Benhissoune, Saïd , Fuentes-Grünewald, Claudio , Walls, Kathy , Page, Mike , Attard, Catherine R M , Cooke, Georgina M , McClusky, Claire F , Banks, Sam C , Barker, Nigel P , Beheregaray, Luciano B
- Date: 2011
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/445529 , vital:74396 , https://doi.org/10.1186/1471-2148-11-176
- Description: Ecosystem engineers facilitate habitat formation and enhance biodiversity, but when they become invasive, they present a critical threat to native communities because they can drastically alter the receiving habitat. Management of such species thus needs to be a priority, but the poorly resolved taxonomy of many ecosystem engineers represents a major obstacle to correctly identifying them as being either native or introduced. We address this dilemma by studying the sea squirt Pyura stolonifera, an important ecosystem engineer that dominates coastal communities particularly in the southern hemisphere. Using DNA sequence data from four independently evolving loci, we aimed to determine levels of cryptic diversity, the invasive or native status of each regional population, and the most appropriate sampling design for identifying the geographic ranges of each evolutionary unit.
- Full Text:
- Authors: Teske, Peter R , Ruis, Marc , McQuaid, Christopher D , Styan, Craig A , Piggott, Maxine P , Benhissoune, Saïd , Fuentes-Grünewald, Claudio , Walls, Kathy , Page, Mike , Attard, Catherine R M , Cooke, Georgina M , McClusky, Claire F , Banks, Sam C , Barker, Nigel P , Beheregaray, Luciano B
- Date: 2011
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/445529 , vital:74396 , https://doi.org/10.1186/1471-2148-11-176
- Description: Ecosystem engineers facilitate habitat formation and enhance biodiversity, but when they become invasive, they present a critical threat to native communities because they can drastically alter the receiving habitat. Management of such species thus needs to be a priority, but the poorly resolved taxonomy of many ecosystem engineers represents a major obstacle to correctly identifying them as being either native or introduced. We address this dilemma by studying the sea squirt Pyura stolonifera, an important ecosystem engineer that dominates coastal communities particularly in the southern hemisphere. Using DNA sequence data from four independently evolving loci, we aimed to determine levels of cryptic diversity, the invasive or native status of each regional population, and the most appropriate sampling design for identifying the geographic ranges of each evolutionary unit.
- Full Text:
'Amanuensis' and 'Steatopygia': the complexity of 'Telling the Tale 'in Zoë Wicomb's David's Story
- Authors: Dass, Minesh
- Date: 2011
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/142599 , vital:38094 , http://dx.doi.org/10.4314/eia.v38i2.3
- Description: Two words, 'amanuensis' and 'steatopygia,' each burdened with its own history, appear in Zoë Wicomb's David's Story with a frequency that commands further consideration. This study shows that these two words are in fact narratives which reveal the tension, inherent in all historical narratives, between that which is denotative or factual and that which is connotative or fictional. Similarly, the words also form the shifting horizon from which we may see history as a narrative of the past that is always also a narrative of the present. The link between these words will ultimately show the complex, compromised role of the narrator and, perhaps, of all historians.
- Full Text:
- Authors: Dass, Minesh
- Date: 2011
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/142599 , vital:38094 , http://dx.doi.org/10.4314/eia.v38i2.3
- Description: Two words, 'amanuensis' and 'steatopygia,' each burdened with its own history, appear in Zoë Wicomb's David's Story with a frequency that commands further consideration. This study shows that these two words are in fact narratives which reveal the tension, inherent in all historical narratives, between that which is denotative or factual and that which is connotative or fictional. Similarly, the words also form the shifting horizon from which we may see history as a narrative of the past that is always also a narrative of the present. The link between these words will ultimately show the complex, compromised role of the narrator and, perhaps, of all historians.
- Full Text:
'Iron on iron': modernism engaging apartheid in some South African railway poems
- Authors: Wright, Laurence
- Date: 2011
- Language: English
- Type: text , article
- Identifier: vital:7068 , http://hdl.handle.net/10962/d1007459 , https://doi.org/10.1080/00138398.2011.626177
- Description: preprint , Modernism tends to be criticised, internationally, as politically conservative. The objection is often valid, although the charge says little about the quality of artistic achievement involved. This article argues that the alliance between Modernism and political conservatism is by no means a necessary one, and that there are instances where modernist vision has been used to convey substantive political insight, effective social critique and solid resistance. To illustrate the contrast,the article juxtaposes the abstract Modernism associated with Ben Nicholson and World War 2, with a neglected strain of South African railway poetry which uses modernist techniques to effect a powerful critique of South Africa’s apartheid dispensation. The article sustains a distinction between universalising modernist art that requires ethical work from its audiences to achieve artistic completion, and art in which modernist vision performs the requisite ethical work within its own formal constraints. Four very different South African railway poems, by Dennis Brutus, John Hendrickse, Alan Paton, and Leonard Koza, are examined and contextualised to demonstrate ways in which a modernist vision has been used to portray the social disruptions caused by apartheid. Modernist techniques are used to turn railway experience into a metonym for massive social disruption,without betraying the social reality of the transport technology involved.
- Full Text:
- Authors: Wright, Laurence
- Date: 2011
- Language: English
- Type: text , article
- Identifier: vital:7068 , http://hdl.handle.net/10962/d1007459 , https://doi.org/10.1080/00138398.2011.626177
- Description: preprint , Modernism tends to be criticised, internationally, as politically conservative. The objection is often valid, although the charge says little about the quality of artistic achievement involved. This article argues that the alliance between Modernism and political conservatism is by no means a necessary one, and that there are instances where modernist vision has been used to convey substantive political insight, effective social critique and solid resistance. To illustrate the contrast,the article juxtaposes the abstract Modernism associated with Ben Nicholson and World War 2, with a neglected strain of South African railway poetry which uses modernist techniques to effect a powerful critique of South Africa’s apartheid dispensation. The article sustains a distinction between universalising modernist art that requires ethical work from its audiences to achieve artistic completion, and art in which modernist vision performs the requisite ethical work within its own formal constraints. Four very different South African railway poems, by Dennis Brutus, John Hendrickse, Alan Paton, and Leonard Koza, are examined and contextualised to demonstrate ways in which a modernist vision has been used to portray the social disruptions caused by apartheid. Modernist techniques are used to turn railway experience into a metonym for massive social disruption,without betraying the social reality of the transport technology involved.
- Full Text:
1H NMR-based kinetic and mechanistic study of unusual skeletal rearrangements of a spirobornyl tosylate derivative
- Lobb, Kevin A, Kaye, Perry T
- Authors: Lobb, Kevin A , Kaye, Perry T
- Date: 2011
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/448858 , vital:74766 , xlink:href="https://doi.org/10.1002/poc.1699"
- Description: 1H NMR analysis of the kinetics of skeletal rearrangement of optically pure 3,3-xylyl-2-exo-bornyl tosylate in CDCl3 indicates the operation of tandem autocatalytic and pseudo-first-order transformations, leading sequentially to a pairof isomeric camphene derivatives and involving partial racemization. Changing the solvent system has been shown topermit the chemoselective isolation of either of the isomeric camphenes.
- Full Text:
- Authors: Lobb, Kevin A , Kaye, Perry T
- Date: 2011
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/448858 , vital:74766 , xlink:href="https://doi.org/10.1002/poc.1699"
- Description: 1H NMR analysis of the kinetics of skeletal rearrangement of optically pure 3,3-xylyl-2-exo-bornyl tosylate in CDCl3 indicates the operation of tandem autocatalytic and pseudo-first-order transformations, leading sequentially to a pairof isomeric camphene derivatives and involving partial racemization. Changing the solvent system has been shown topermit the chemoselective isolation of either of the isomeric camphenes.
- Full Text:
A Baseline Numeric Analysis of Network Telescope Data for Network Incident Discovery
- Cowie, Bradley, Irwin, Barry V W
- Authors: Cowie, Bradley , Irwin, Barry V W
- Date: 2011
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/427971 , vital:72477 , https://www.researchgate.net/profile/Barry-Ir-win/publication/326225071_An_Evaluation_of_Trading_Bands_as_Indicators_for_Network_Telescope_Datasets/links/5b3f231a4585150d2309e1c0/An-Evaluation-of-Trading-Bands-as-Indicators-for-Network-Telescope-Datasets.pdf
- Description: This paper investigates the value of Network Telescope data as a mechanism for network incident discovery by considering data summa-rization, simple heuristic identification and deviations from previously observed traffic distributions. It is important to note that the traffic ob-served is obtained from a Network Telescope and thus does not expe-rience the same fluctuations or vagaries experienced by normal traffic. The datasets used for this analysis were obtained from a Network Tele-scope for the time period August 2005 to September 2009 which had been allocated a Class-C network address block at Rhodes University. The nature of the datasets were considered in terms of simple statistical measures obtained through data summarization which greatly reduced the processing and observation required to determine whether an inci-dent had occurred. However, this raised issues relating to the time in-terval used for identification of an incident. A brief discussion into statis-tical summaries of Network Telescope data as" good" security metrics is provided. The summaries derived were then used to seek for signs of anomalous network activity. Anomalous activity detected was then rec-onciled by considering incidents that had occurred in the same or simi-lar time interval. Incidents identified included Conficker, Win32. RinBot, DDoS and Norton Netware vulnerabilities. Detection techniques includ-ed identification of rapid growth in packet count, packet size deviations, changes in the composition of the traffic expressed as a ratio of its constituents and changes in the modality of the data. Discussion into the appropriateness of this sort of manual analysis is provided and suggestions towards an automated solution are discussed.
- Full Text:
- Authors: Cowie, Bradley , Irwin, Barry V W
- Date: 2011
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/427971 , vital:72477 , https://www.researchgate.net/profile/Barry-Ir-win/publication/326225071_An_Evaluation_of_Trading_Bands_as_Indicators_for_Network_Telescope_Datasets/links/5b3f231a4585150d2309e1c0/An-Evaluation-of-Trading-Bands-as-Indicators-for-Network-Telescope-Datasets.pdf
- Description: This paper investigates the value of Network Telescope data as a mechanism for network incident discovery by considering data summa-rization, simple heuristic identification and deviations from previously observed traffic distributions. It is important to note that the traffic ob-served is obtained from a Network Telescope and thus does not expe-rience the same fluctuations or vagaries experienced by normal traffic. The datasets used for this analysis were obtained from a Network Tele-scope for the time period August 2005 to September 2009 which had been allocated a Class-C network address block at Rhodes University. The nature of the datasets were considered in terms of simple statistical measures obtained through data summarization which greatly reduced the processing and observation required to determine whether an inci-dent had occurred. However, this raised issues relating to the time in-terval used for identification of an incident. A brief discussion into statis-tical summaries of Network Telescope data as" good" security metrics is provided. The summaries derived were then used to seek for signs of anomalous network activity. Anomalous activity detected was then rec-onciled by considering incidents that had occurred in the same or simi-lar time interval. Incidents identified included Conficker, Win32. RinBot, DDoS and Norton Netware vulnerabilities. Detection techniques includ-ed identification of rapid growth in packet count, packet size deviations, changes in the composition of the traffic expressed as a ratio of its constituents and changes in the modality of the data. Discussion into the appropriateness of this sort of manual analysis is provided and suggestions towards an automated solution are discussed.
- Full Text:
A comparison of three techniques for fluorochrome marking of juvenile Clarias gariepinus otoliths
- Wartenberg, Reece, Booth, Anthony J, Weyl, Olaf L F
- Authors: Wartenberg, Reece , Booth, Anthony J , Weyl, Olaf L F
- Date: 2011
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/123520 , vital:35450 , https://doi.10.3377/004.046.0119
- Description: African sharptooth catfish, Clarias gariepinus (Burchell 1822), is widely distributed with a natural range that extends from southern Turkey to the Orange River, South Africa (Skelton 2001). In addition to translocations within its southerly range (Cambray 2003), Cambray (2005) noted that as a result of poor aquaculture practices and introductions from a number of unknown sources, C. gariepinus has now invaded South America, Europe, Asia, and Australia. Its life history characteristics include a fast growth rate to a maximum length of 1300mmtotal length (TL) (Bruton 1976), a high fecundity, an omnivorous diet and the ability to breathe air (de Moor & Bruton 1988; Cambray 2003). Understanding the biology and population dynamics of this invader would assist in its management and possibly eradication.
- Full Text:
- Authors: Wartenberg, Reece , Booth, Anthony J , Weyl, Olaf L F
- Date: 2011
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/123520 , vital:35450 , https://doi.10.3377/004.046.0119
- Description: African sharptooth catfish, Clarias gariepinus (Burchell 1822), is widely distributed with a natural range that extends from southern Turkey to the Orange River, South Africa (Skelton 2001). In addition to translocations within its southerly range (Cambray 2003), Cambray (2005) noted that as a result of poor aquaculture practices and introductions from a number of unknown sources, C. gariepinus has now invaded South America, Europe, Asia, and Australia. Its life history characteristics include a fast growth rate to a maximum length of 1300mmtotal length (TL) (Bruton 1976), a high fecundity, an omnivorous diet and the ability to breathe air (de Moor & Bruton 1988; Cambray 2003). Understanding the biology and population dynamics of this invader would assist in its management and possibly eradication.
- Full Text:
A comparison of three techniques for fluorochrome marking of juvenile Clarias gariepinus otoliths
- Wartenberg, Reece, Booth, Anthony J, Weyl, Olaf L F
- Authors: Wartenberg, Reece , Booth, Anthony J , Weyl, Olaf L F
- Date: 2011
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/446742 , vital:74557 , https://doi.org/10.1080/15627020.2011.11407480
- Description: Intramuscular injection of the antibiotic oxytetracycline (OTC) has been the only method previously employed for chemically marking C. gariepinus otoliths for ageing studies. This study compared intramuscular injection, immersion, and dietary incorporation methods of administering OTC to determine the most effective technique. No differences in either growth or mortality were found between experimental groups while intramuscular injection of OTC was found to be superior to either mass immersion or dietary inclusion of OTC when marking Clarias gariepinus otoliths.
- Full Text:
- Authors: Wartenberg, Reece , Booth, Anthony J , Weyl, Olaf L F
- Date: 2011
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/446742 , vital:74557 , https://doi.org/10.1080/15627020.2011.11407480
- Description: Intramuscular injection of the antibiotic oxytetracycline (OTC) has been the only method previously employed for chemically marking C. gariepinus otoliths for ageing studies. This study compared intramuscular injection, immersion, and dietary incorporation methods of administering OTC to determine the most effective technique. No differences in either growth or mortality were found between experimental groups while intramuscular injection of OTC was found to be superior to either mass immersion or dietary inclusion of OTC when marking Clarias gariepinus otoliths.
- Full Text:
A framework for DNS based detection and mitigation of malware infections on a network
- Stalmans, Etienne, Irwin, Barry V W
- Authors: Stalmans, Etienne , Irwin, Barry V W
- Date: 2011
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/429827 , vital:72642 , 10.1109/ISSA.2011.6027531
- Description: Modern botnet trends have lead to the use of IP and domain fast-fluxing to avoid detection and increase resilience. These techniques bypass traditional detection systems such as blacklists and intrusion detection systems. The Domain Name Service (DNS) is one of the most prevalent protocols on modern networks and is essential for the correct operation of many network activities, including botnet activity. For this reason DNS forms the ideal candidate for monitoring, detecting and mit-igating botnet activity. In this paper a system placed at the network edge is developed with the capability to detect fast-flux domains using DNS queries. Multiple domain features were examined to determine which would be most effective in the classification of domains. This is achieved using a C5.0 decision tree classifier and Bayesian statistics, with positive samples being labeled as potentially malicious and nega-tive samples as legitimate domains. The system detects malicious do-main names with a high degree of accuracy, minimising the need for blacklists. Statistical methods, namely Naive Bayesian, Bayesian, Total Variation distance and Probability distribution are applied to detect mali-cious domain names. The detection techniques are tested against sample traffic and it is shown that malicious traffic can be detected with low false positive rates.
- Full Text:
- Authors: Stalmans, Etienne , Irwin, Barry V W
- Date: 2011
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/429827 , vital:72642 , 10.1109/ISSA.2011.6027531
- Description: Modern botnet trends have lead to the use of IP and domain fast-fluxing to avoid detection and increase resilience. These techniques bypass traditional detection systems such as blacklists and intrusion detection systems. The Domain Name Service (DNS) is one of the most prevalent protocols on modern networks and is essential for the correct operation of many network activities, including botnet activity. For this reason DNS forms the ideal candidate for monitoring, detecting and mit-igating botnet activity. In this paper a system placed at the network edge is developed with the capability to detect fast-flux domains using DNS queries. Multiple domain features were examined to determine which would be most effective in the classification of domains. This is achieved using a C5.0 decision tree classifier and Bayesian statistics, with positive samples being labeled as potentially malicious and nega-tive samples as legitimate domains. The system detects malicious do-main names with a high degree of accuracy, minimising the need for blacklists. Statistical methods, namely Naive Bayesian, Bayesian, Total Variation distance and Probability distribution are applied to detect mali-cious domain names. The detection techniques are tested against sample traffic and it is shown that malicious traffic can be detected with low false positive rates.
- Full Text:
A Framework for DNS Based Detection of Botnets at the ISP Level
- Stalmans, Etienne, Irwin, Barry V W
- Authors: Stalmans, Etienne , Irwin, Barry V W
- Date: 2011
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/427984 , vital:72478 , https://www.researchgate.net/profile/Barry-Ir-win/publication/327622932_A_Framework_for_DNS_Based_Detection_of_Botnets_at_the_ISP_Level/links/5b9a14e1458515310583fc19/A-Framework-for-DNS-Based-Detection-of-Botnets-at-the-ISP-Level.pdf
- Description: The rapid expansion of networks and increase in internet connected devices has lead to a large number of hosts susceptible to virus infec-tion. Infected hosts are controlled by attackers and form so called bot-nets. These botnets are used to steal data, mask malicious activity and perform distributed denial of service attacks. Traditional protection mechanisms rely on host based detection of viruses. These systems are failing due to the rapid increase in the number of vulnerable hosts and attacks that easily bypass detection mechanisms. This paper pro-poses moving protection from the individual hosts to the Internet Ser-vice Provider (ISP), allowing for the detection and prevention of botnet traffic. DNS traffic inspection allows for the development of a lightweight and accurate classifier that has little or no effect on network perfor-mance. By preventing botnet activity at the ISP level, it is hoped that the threat of botnets can largely be mitigated.
- Full Text:
- Authors: Stalmans, Etienne , Irwin, Barry V W
- Date: 2011
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/427984 , vital:72478 , https://www.researchgate.net/profile/Barry-Ir-win/publication/327622932_A_Framework_for_DNS_Based_Detection_of_Botnets_at_the_ISP_Level/links/5b9a14e1458515310583fc19/A-Framework-for-DNS-Based-Detection-of-Botnets-at-the-ISP-Level.pdf
- Description: The rapid expansion of networks and increase in internet connected devices has lead to a large number of hosts susceptible to virus infec-tion. Infected hosts are controlled by attackers and form so called bot-nets. These botnets are used to steal data, mask malicious activity and perform distributed denial of service attacks. Traditional protection mechanisms rely on host based detection of viruses. These systems are failing due to the rapid increase in the number of vulnerable hosts and attacks that easily bypass detection mechanisms. This paper pro-poses moving protection from the individual hosts to the Internet Ser-vice Provider (ISP), allowing for the detection and prevention of botnet traffic. DNS traffic inspection allows for the development of a lightweight and accurate classifier that has little or no effect on network perfor-mance. By preventing botnet activity at the ISP level, it is hoped that the threat of botnets can largely be mitigated.
- Full Text:
A Framework for the Management of Operator Policies and User Preferences for Service Compositions in the IP Multimedia Subsystem
- Tsietsi, Mosiuoa, Terzoli, Alfredo, Wells, George C
- Authors: Tsietsi, Mosiuoa , Terzoli, Alfredo , Wells, George C
- Date: 2011
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/430680 , vital:72708 , https://ieeexplore.ieee.org/abstract/document/6032212
- Description: The IP Multimedia Subsystem (IMS) is a telecommunication middleware platform with robust service features that enables the delivery of a wide range of services to mobile network subscribers. Network operators are encouraged to develop services from service building blocks in order to avoid redundancies by re-using existing functionality. In this environ-ment, operators must be able to control the service execution chain in order to prevent undesirable interactions from occurring between indi-vidual building blocks. It is also in their interests to provide subscribers with personalisation options so that they can modify service composi-tions and define their own preferences for how they would like their ser-vices to behave during live sessions. This paper describes a solution for these challenges that involves the storage of service information in an XDMS and allows operator staff and subscribers to manage this in-formation using the XCAP protocol. The ETSI-defined XCAP applica-tion usage named simservs was chosen to demonstrate an application usage that can be used to create service compositions in XML format. A prototype is described that uses components of the open source Mo-bicents project to verify the suitability of the design. This work is part of a larger effort aimed at modeling interaction management in the IMS through the use of a service broker that is part of an extended IMS ser-vice layer (EISL). The service broker's functional and structural architec-ture have not yet been standardised.
- Full Text:
- Authors: Tsietsi, Mosiuoa , Terzoli, Alfredo , Wells, George C
- Date: 2011
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/430680 , vital:72708 , https://ieeexplore.ieee.org/abstract/document/6032212
- Description: The IP Multimedia Subsystem (IMS) is a telecommunication middleware platform with robust service features that enables the delivery of a wide range of services to mobile network subscribers. Network operators are encouraged to develop services from service building blocks in order to avoid redundancies by re-using existing functionality. In this environ-ment, operators must be able to control the service execution chain in order to prevent undesirable interactions from occurring between indi-vidual building blocks. It is also in their interests to provide subscribers with personalisation options so that they can modify service composi-tions and define their own preferences for how they would like their ser-vices to behave during live sessions. This paper describes a solution for these challenges that involves the storage of service information in an XDMS and allows operator staff and subscribers to manage this in-formation using the XCAP protocol. The ETSI-defined XCAP applica-tion usage named simservs was chosen to demonstrate an application usage that can be used to create service compositions in XML format. A prototype is described that uses components of the open source Mo-bicents project to verify the suitability of the design. This work is part of a larger effort aimed at modeling interaction management in the IMS through the use of a service broker that is part of an extended IMS ser-vice layer (EISL). The service broker's functional and structural architec-ture have not yet been standardised.
- Full Text:
A fuzz testing framework for evaluating and securing network applications
- Zeisberger, Sascha, Irwin, Barry V W
- Authors: Zeisberger, Sascha , Irwin, Barry V W
- Date: 2011
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/428000 , vital:72479 , https://www.researchgate.net/profile/Barry-Ir-win/publication/327622655_A_Fuzz_Testing_Framework_for_Evaluating_and_Securing_Network_Applications/links/5b9a153b92851c4ba8181b0d/A-Fuzz-Testing-Framework-for-Evaluating-and-Securing-Network-Applications.pdf
- Description: Research has shown that fuzz-testing is an effective means of increasing the quality and security of software and systems. This project proposes the im-plementation of a testing framework based on numerous fuzz-testing tech-niques. The framework will allow a user to detect errors in applications and locate critical areas in the applications that are responsible for the detected errors. The aim is to provide an all-encompassing testing framework that will allow a developer to quickly and effectively deploy fuzz tests on an applica-tion and ensure a higher level of quality control before deployment.
- Full Text:
- Authors: Zeisberger, Sascha , Irwin, Barry V W
- Date: 2011
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/428000 , vital:72479 , https://www.researchgate.net/profile/Barry-Ir-win/publication/327622655_A_Fuzz_Testing_Framework_for_Evaluating_and_Securing_Network_Applications/links/5b9a153b92851c4ba8181b0d/A-Fuzz-Testing-Framework-for-Evaluating-and-Securing-Network-Applications.pdf
- Description: Research has shown that fuzz-testing is an effective means of increasing the quality and security of software and systems. This project proposes the im-plementation of a testing framework based on numerous fuzz-testing tech-niques. The framework will allow a user to detect errors in applications and locate critical areas in the applications that are responsible for the detected errors. The aim is to provide an all-encompassing testing framework that will allow a developer to quickly and effectively deploy fuzz tests on an applica-tion and ensure a higher level of quality control before deployment.
- Full Text:
A research tool for analysing and monitoring the Extent to which Environmental issues are integrated into teachers’ lessons
- Authors: Nsubuga, Yvonne
- Date: 2011
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/386447 , vital:68142 , xlink:href="https://www.ajol.info/index.php/sajee/article/view/122246"
- Description: South Africa enjoys strong policy support for the integration of environmental issues into school curricula. However, much doubt exists over the extent to which this has been converted into appropriate classroom practice at the majority of under-resourced rural schools in the country. This article reports on a study which piloted a research tool which can be used to analyse teachers’ lessons, with the aim of gaining insight into the extent to which they integrate natural resource management issues. The research tool was based on Bernstein’s concept of classification and consisted of five indicators of natural resource management integration into Life Sciences lessons. The study contributes to the design of research tools that can be used to analyse and monitor the integration of environmental issues into teachers’ lessons. It also provides some insight into the environmental content of a sample of Grade 10 Life Sciences lessons at four rural underresourced schools in the Eastern Cape.
- Full Text:
- Authors: Nsubuga, Yvonne
- Date: 2011
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/386447 , vital:68142 , xlink:href="https://www.ajol.info/index.php/sajee/article/view/122246"
- Description: South Africa enjoys strong policy support for the integration of environmental issues into school curricula. However, much doubt exists over the extent to which this has been converted into appropriate classroom practice at the majority of under-resourced rural schools in the country. This article reports on a study which piloted a research tool which can be used to analyse teachers’ lessons, with the aim of gaining insight into the extent to which they integrate natural resource management issues. The research tool was based on Bernstein’s concept of classification and consisted of five indicators of natural resource management integration into Life Sciences lessons. The study contributes to the design of research tools that can be used to analyse and monitor the integration of environmental issues into teachers’ lessons. It also provides some insight into the environmental content of a sample of Grade 10 Life Sciences lessons at four rural underresourced schools in the Eastern Cape.
- Full Text:
A review of marine phylogeography in southern Africa
- Teske, Peter R, Von der Heyden, Sophie, McQuaid, Christopher D, Barker, Nigel P
- Authors: Teske, Peter R , Von der Heyden, Sophie , McQuaid, Christopher D , Barker, Nigel P
- Date: 2011
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/445392 , vital:74382 , https://hdl.handle.net/10520/EJC97146
- Description: The southern African marine realm is located at the transition zone between the Atlantic and Indo-Pacific biomes. Its biodiversity is particularly rich and comprises faunal and floral elements from the two major oceanic regions, as well as a large number of endemics. Within this realm, strikingly different biota occur in close geographic proximity to each other, and many of the species with distributions spanning two or more of the region's marine biogeographic provinces are divided into evolutionary units that can often only be distinguished on the basis of genetic data. In this review, we describe the state of marine phylogeography in southern Africa, that is, the study of evolutionary relationships at the species level, or amongst closely related species, in relation to the region's marine environment. We focus particularly on coastal phylogeography, where much progress has recently been made in identifying phylogeographic breaks and explaining how they originated and are maintained. We also highlight numerous shortcomings that should be addressed in the near future. These include: the limited data available for commercially important organisms, particularly offshore species; the paucity of oceanographic data for nearshore areas; a dearth of studies based on multilocus data; and the fact that studying the role of diversifying selection in speciation has been limited to physiological approaches to the exclusion of genetics. It is becoming apparent that the southern African marine realm is one of the world's most interesting environments in which to study the evolutionary processes that shape not only regional, but also global patterns of marine biodiversity.
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- Authors: Teske, Peter R , Von der Heyden, Sophie , McQuaid, Christopher D , Barker, Nigel P
- Date: 2011
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/445392 , vital:74382 , https://hdl.handle.net/10520/EJC97146
- Description: The southern African marine realm is located at the transition zone between the Atlantic and Indo-Pacific biomes. Its biodiversity is particularly rich and comprises faunal and floral elements from the two major oceanic regions, as well as a large number of endemics. Within this realm, strikingly different biota occur in close geographic proximity to each other, and many of the species with distributions spanning two or more of the region's marine biogeographic provinces are divided into evolutionary units that can often only be distinguished on the basis of genetic data. In this review, we describe the state of marine phylogeography in southern Africa, that is, the study of evolutionary relationships at the species level, or amongst closely related species, in relation to the region's marine environment. We focus particularly on coastal phylogeography, where much progress has recently been made in identifying phylogeographic breaks and explaining how they originated and are maintained. We also highlight numerous shortcomings that should be addressed in the near future. These include: the limited data available for commercially important organisms, particularly offshore species; the paucity of oceanographic data for nearshore areas; a dearth of studies based on multilocus data; and the fact that studying the role of diversifying selection in speciation has been limited to physiological approaches to the exclusion of genetics. It is becoming apparent that the southern African marine realm is one of the world's most interesting environments in which to study the evolutionary processes that shape not only regional, but also global patterns of marine biodiversity.
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A revision of the Pyura stolonifera species complex (Tunicata, Ascidiacea), with a description of a new species from Australia
- Authors: Teske, Peter R , Ruis, Marc
- Date: 2011
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/445654 , vital:74411 , https://www.biotaxa.org/Zootaxa/article/view/zootaxa.2754.1.2
- Description: Pyura stolonifera is a large solitary ascidian found in Africa, Australasia and South America. The taxonomic status of different populations of this species is disputed, especially since there is evidence for several distinct morphological and genetic units that point towards the existence of multiple cryptic species. While some researchers still recognize P. stolonifera as a single species, others treat the different populations as distinct species. Here, we present a revision of the P. stolonifera species complex based on the examination of samples from all regions where there are reliable reports of this taxon. We recognize four species that are both morphologically and genetically distinct, one of which is new to science and is formally described here. This species is morphologically distinct from the other three members of the species complex in terms of the colour and texture of the tunic, the arrangement of the gonads within the gut and the shape of the dorsal tubercle, among other characters. We name the new species Pyura dalbyi after Dr. J.E. Dalby Jr., whose research on its ecology and distribution provided the incentive for examining this species more closely.
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- Authors: Teske, Peter R , Ruis, Marc
- Date: 2011
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/445654 , vital:74411 , https://www.biotaxa.org/Zootaxa/article/view/zootaxa.2754.1.2
- Description: Pyura stolonifera is a large solitary ascidian found in Africa, Australasia and South America. The taxonomic status of different populations of this species is disputed, especially since there is evidence for several distinct morphological and genetic units that point towards the existence of multiple cryptic species. While some researchers still recognize P. stolonifera as a single species, others treat the different populations as distinct species. Here, we present a revision of the P. stolonifera species complex based on the examination of samples from all regions where there are reliable reports of this taxon. We recognize four species that are both morphologically and genetically distinct, one of which is new to science and is formally described here. This species is morphologically distinct from the other three members of the species complex in terms of the colour and texture of the tunic, the arrangement of the gonads within the gut and the shape of the dorsal tubercle, among other characters. We name the new species Pyura dalbyi after Dr. J.E. Dalby Jr., whose research on its ecology and distribution provided the incentive for examining this species more closely.
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A Search for Conjunctions at a Time of Direction-setting Review and Synthesis
- Authors: O'Donoghue, Rob B
- Date: 2011
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/387134 , vital:68209 , xlink:href="https://www.ajol.info/index.php/sajee/article/view/122240"
- Description: This journal reflects a diversity of environment and sustainability education research and viewpoints alongside two synthesis papers. Read as a whole and within a widely held ideal that diversity reflects resilience, the environment and education for sustainable development landscape in Africa might be said to be healthy and proliferating. But read against the pressure to produce tangible evidence of change on an African landscape of persistent climate variation and poverty, along with a widening gap between rich and poor, the picture remains challenging. These contrasting readings are notable at a time when we are looking towards the Association for the Development of Education in Africa (ADEA) Triennial in February, 2012, the Rio+20 Earth Summit in June 2012 and our own EEASA +30 conference in September 2012. The UN Decade of Education for Sustainable Development is characterised by a proliferation of education imperatives. These emerged as modern education in response to the issues of the day and now a modernity in deepening crisis.
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- Authors: O'Donoghue, Rob B
- Date: 2011
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/387134 , vital:68209 , xlink:href="https://www.ajol.info/index.php/sajee/article/view/122240"
- Description: This journal reflects a diversity of environment and sustainability education research and viewpoints alongside two synthesis papers. Read as a whole and within a widely held ideal that diversity reflects resilience, the environment and education for sustainable development landscape in Africa might be said to be healthy and proliferating. But read against the pressure to produce tangible evidence of change on an African landscape of persistent climate variation and poverty, along with a widening gap between rich and poor, the picture remains challenging. These contrasting readings are notable at a time when we are looking towards the Association for the Development of Education in Africa (ADEA) Triennial in February, 2012, the Rio+20 Earth Summit in June 2012 and our own EEASA +30 conference in September 2012. The UN Decade of Education for Sustainable Development is characterised by a proliferation of education imperatives. These emerged as modern education in response to the issues of the day and now a modernity in deepening crisis.
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A short composition portfolio
- Buitendag, Kingsley Alexander
- Authors: Buitendag, Kingsley Alexander
- Date: 2011
- Subjects: Music -- South Africa Composition (Music)
- Language: English
- Type: text , Thesis , Masters , MMus
- Identifier: vital:2632 , http://hdl.handle.net/10962/d1002297
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- Authors: Buitendag, Kingsley Alexander
- Date: 2011
- Subjects: Music -- South Africa Composition (Music)
- Language: English
- Type: text , Thesis , Masters , MMus
- Identifier: vital:2632 , http://hdl.handle.net/10962/d1002297
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A stable isotope approach for the early detection and identification of N loading in aquatic ecosystems
- Hill, Jaclyn M, Kaehler, Sven, Hill, Martin P, Coetzee, Julie A
- Authors: Hill, Jaclyn M , Kaehler, Sven , Hill, Martin P , Coetzee, Julie A
- Date: 2011
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/444491 , vital:74245 , https://www.wrc.org.za/wp-content/uploads/mdocs/KV 280.pdf
- Description: Global increases in urbanization and anthropogenic activity within wa-tersheds and catchment areas have resulted in excessive nitrogen loads in aquatic ecosystems. South Africa is deeply dependent on nat-ural resources for its economic health and as a consequence is particu-larly vulnerable to the degradation of its natural capital. Increased nitro-gen loading can result in widespread aquatic ecosystem degradation including: harmful algal blooms, increased turbidity, hypoxia, loss of aquatic vegetation and habitat and fish kills, it is also one of the mecha-nisms driving aquatic weed invasions. Understanding the fate and pro-cessing of anthropogenic nutrients in natural systems is therefore criti-cal for both preserving the well-being and biotic heritage for future gen-erations as well as providing a tremendous opportunity to improve the management driven by science. The objectives of this study were to evaluate the feasibility of mapping anthropogenic pollution through sta-ble isotopes signatures of aquatic plants, to investigate the potential for identifying different pollution sources, concentrations and distributions in a freshwater environment and to determine the utility of these tech-niques in indentifying early eutrophication.
- Full Text:
- Authors: Hill, Jaclyn M , Kaehler, Sven , Hill, Martin P , Coetzee, Julie A
- Date: 2011
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/444491 , vital:74245 , https://www.wrc.org.za/wp-content/uploads/mdocs/KV 280.pdf
- Description: Global increases in urbanization and anthropogenic activity within wa-tersheds and catchment areas have resulted in excessive nitrogen loads in aquatic ecosystems. South Africa is deeply dependent on nat-ural resources for its economic health and as a consequence is particu-larly vulnerable to the degradation of its natural capital. Increased nitro-gen loading can result in widespread aquatic ecosystem degradation including: harmful algal blooms, increased turbidity, hypoxia, loss of aquatic vegetation and habitat and fish kills, it is also one of the mecha-nisms driving aquatic weed invasions. Understanding the fate and pro-cessing of anthropogenic nutrients in natural systems is therefore criti-cal for both preserving the well-being and biotic heritage for future gen-erations as well as providing a tremendous opportunity to improve the management driven by science. The objectives of this study were to evaluate the feasibility of mapping anthropogenic pollution through sta-ble isotopes signatures of aquatic plants, to investigate the potential for identifying different pollution sources, concentrations and distributions in a freshwater environment and to determine the utility of these tech-niques in indentifying early eutrophication.
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A white man in exile
- Authors: Krueger, Anton
- Date: 2011
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/229459 , vital:49677 , xlink:href="https://doi.org/10.1080/10137548.2011.636974"
- Description: This article explores intersections between understandings of masculinity and nationalism. Etymologically, ‘patriotism’ refers to a love for a fatherland and a patriarchal order; it includes notions of loyalty, honour and a range of qualities often associated with conceptions of masculinity. But if gender remains fixed to these normative constructions, what happens to one’s sense of masculine identity when the national state changes? My interest lies in exploring how white South African men have been repositioned in terms of a shift in their gendered identification, with a reflection on the possibly tragic consequences of maintaining an overly rigid gender role identification. As long as masculinity is embedded within nationalism, it will be caught up within a defensive reactive mode which can turn self-destructive. In order to explore these ideas the article employs as its central metaphor the character of Dawid Olivier, who is the protagonist of Athol Fugard’s Sorrows and Rejoicings (2002).
- Full Text:
- Authors: Krueger, Anton
- Date: 2011
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/229459 , vital:49677 , xlink:href="https://doi.org/10.1080/10137548.2011.636974"
- Description: This article explores intersections between understandings of masculinity and nationalism. Etymologically, ‘patriotism’ refers to a love for a fatherland and a patriarchal order; it includes notions of loyalty, honour and a range of qualities often associated with conceptions of masculinity. But if gender remains fixed to these normative constructions, what happens to one’s sense of masculine identity when the national state changes? My interest lies in exploring how white South African men have been repositioned in terms of a shift in their gendered identification, with a reflection on the possibly tragic consequences of maintaining an overly rigid gender role identification. As long as masculinity is embedded within nationalism, it will be caught up within a defensive reactive mode which can turn self-destructive. In order to explore these ideas the article employs as its central metaphor the character of Dawid Olivier, who is the protagonist of Athol Fugard’s Sorrows and Rejoicings (2002).
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A “place in which to cry”: the place for race and a home for shame in Zoë Wicomb's Playing in the Light
- Authors: Dass, Minesh
- Date: 2011
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/142588 , vital:38093 , DOI: 10.1080/1013929X.2011.602910
- Description: In Zoë Wicomb's Playing in the Light, the main character's troubled sense of identity (brought about by her parents' shameful decision to ‘play white’) is viscerally symbolised by her discomfort in her own and others' homes. In her Cape Town apartment she has nightmares about other houses. Her visits to her family home, where her elderly father lives alone, are similarly burdened by presences and memories she finds unwelcoming. And, her extended vacation to the UK, once she has discovered her family's secret, is a choice of “a place in which to cry” (Wicomb 2006: 191).
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- Authors: Dass, Minesh
- Date: 2011
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/142588 , vital:38093 , DOI: 10.1080/1013929X.2011.602910
- Description: In Zoë Wicomb's Playing in the Light, the main character's troubled sense of identity (brought about by her parents' shameful decision to ‘play white’) is viscerally symbolised by her discomfort in her own and others' homes. In her Cape Town apartment she has nightmares about other houses. Her visits to her family home, where her elderly father lives alone, are similarly burdened by presences and memories she finds unwelcoming. And, her extended vacation to the UK, once she has discovered her family's secret, is a choice of “a place in which to cry” (Wicomb 2006: 191).
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Aardvark burrows: a potential resource for animals in arid and semi-arid environments
- Whittington-Jones, Gareth M, Bernard, Ric T F, Parker, Daniel M
- Authors: Whittington-Jones, Gareth M , Bernard, Ric T F , Parker, Daniel M
- Date: 2011
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/443852 , vital:74166 , https://doi.org/10.1080/15627020.2011.11407509
- Description: Arid and semi-arid environments are characterized by extreme fluctuations in temperature and low rainfall, which present significant challenges to the animals inhabiting these areas. However, the presence of burrows may allow animals to avoid climatic extremes and predators and may act as valuable foraging sites. We assessed the microhabitat conditions (maximum and minimum temperature, relative humidity and seed abundance) of aardvark (Orycteropus afer) burrows in relation to paired non-burrow areas at three sites in South Africa. We also describe the extent to which they are used as resources by other vertebrates. Maximum temperatures were significantly lower and minimum temperatures and relative humidity values were significantly higher inside the burrows than outside. The concentration of seeds inside the burrows and at the paired non-burrow sites was similar. Twenty-seven vertebrate species (21 mammals, two birds, three reptiles and one amphibian) were recorded making use of the burrows and it is likely that these species accrue benefits (e.g. a buffered microclimate) from burrow use. However, our sampling was biased towards mammals and nocturnal species. Consequently, we recommend further work to establish the overall reliance of vertebrate taxa on aardvark burrows in arid and semi-arid environments.
- Full Text:
- Authors: Whittington-Jones, Gareth M , Bernard, Ric T F , Parker, Daniel M
- Date: 2011
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/443852 , vital:74166 , https://doi.org/10.1080/15627020.2011.11407509
- Description: Arid and semi-arid environments are characterized by extreme fluctuations in temperature and low rainfall, which present significant challenges to the animals inhabiting these areas. However, the presence of burrows may allow animals to avoid climatic extremes and predators and may act as valuable foraging sites. We assessed the microhabitat conditions (maximum and minimum temperature, relative humidity and seed abundance) of aardvark (Orycteropus afer) burrows in relation to paired non-burrow areas at three sites in South Africa. We also describe the extent to which they are used as resources by other vertebrates. Maximum temperatures were significantly lower and minimum temperatures and relative humidity values were significantly higher inside the burrows than outside. The concentration of seeds inside the burrows and at the paired non-burrow sites was similar. Twenty-seven vertebrate species (21 mammals, two birds, three reptiles and one amphibian) were recorded making use of the burrows and it is likely that these species accrue benefits (e.g. a buffered microclimate) from burrow use. However, our sampling was biased towards mammals and nocturnal species. Consequently, we recommend further work to establish the overall reliance of vertebrate taxa on aardvark burrows in arid and semi-arid environments.
- Full Text: