Deep Routing Simulation
- Authors: Irwin, Barry V W , Herbert, Alan
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/430353 , vital:72685 , https://www.academic-bookshop.com/ourshop/prod_2546879-ICIW-2013-8th-International-Conference-on-Information-Warfare-and-Security.html
- Description: This paper discusses a dataset of some 16 million packets targeting port 445/tcp collected by a network telescope utilising a /24 netblock in South African IP address space. An initial overview of the collected data is provided. This is followed by a detailed analysis of the packet characteristics observed, including size and TTL. The peculiarities of the observed target selection and the results of the flaw in the Conficker worm's propagation algorithm are presented. An analysis of the 4 million observed source hosts is reported, grouped by both packet counts and the number of distinct hosts per network address block. Address blocks of size /8, 16 and 24 are used for groupings. The localisation, by geographic region and numerical proximity, of high ranking aggregate netblocks is highlighted. The observed shift in geopolitical origins observed during the evolution of the Conficker worm is also discussed. The paper concludes with some overall analyses, and consideration of the application of network telescopes to the monitoring of such outbreaks in the future.
- Full Text:
- Date Issued: 2013
E-skills training on communal, fixed infrastructure as an activator of personal use of mobile internet
- Authors: Gumbo, Sibukelo , Terzoli, Alfredo
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/430716 , vital:72710 , https://ieeexplore.ieee.org/abstract/document/6701781
- Description: In the second semester of 2012, training in computer literacy was of-fered in the Dwesa area, in deep rural South Africa, within the footprint of the Siyakhula Living Lab. Training of this nature is essential to make ICT access meaningful in such areas, and avoid wasteful `box drop-ping', unfortunately not uncommon. The training was done using com-munal fixed infrastructure located in schools but, interestingly, activated or deepened the use of mobile intemet among the people that attended the training. This paper contributes on the ongoing debate on whether mobile devices are the one and only solution to ICT access in rural (and peri-urban) poor settings in Africa.
- Full Text:
- Date Issued: 2013
Finding the best clay: experiences of rural potter Alice Gqa Nongebeza contextualised
- Authors: Steele, John
- Date: 2013
- Language: English
- Type: text , Article
- Identifier: http://hdl.handle.net/11260/1023 , vital:30216
- Description: When creating artefacts that belong in the material world artists choose specific raw materials for particular reasons, including that selected resources are accessible and well suited to fitness for purpose and expression of intentions. Many potters in Africa are engaged in zero electricity usage ceramics practice, and each creative cycle usually starts with extracting clay from local sites according to preferences and well established procedures that may sometimes include certain rituals. Ways in which some potters who source their own clay are particular about certain factors that are thought to be capable of influencing the effectiveness of physical properties of that raw material are explored, with particular reference to what is known about the practices of Eastern Cape potter Alice Gqa Nongebeza, of Nkonxeni Village [31°37‘59.66“S, 29°23‘22.26“E], Tombo, near Port St Johns. Specific choices enacted by potters when gathering and using clayey raw materials are considered in order to better understand some aspects of conceptual and social frameworks that may influence clay extraction procedures. Thus, by means of comparisons between particular potter’s practices, as well as through analysis of interview material and observed events, this paper aims to contextualise how it transpired, inter alia, that clay seams close to the Nongebeza homestead were ignored by her in favour of a relatively distant and almost inaccessible site that yielded a particular clay well suited to her unique firing style of placing raw ware onto an already roaring bonfire, thereby effectively creating pots for daily use and enjoyment
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- Date Issued: 2013
Mg/Triethylammonium Formate: A Useful System for Reductive Dimerization of Araldehydes into Pinacols;Nitroarenes into Azoarenes and Azoarenes into Hydrazoarenes
- Authors: Pamar, M Geeter , Govender, P , Muthusamy, K , Krause, Rui W M
- Date: 2013
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/125107 , vital:35729 , https://doi.org/10.13005/ojc/290316
- Description: Studies are reported which describes the effectiveness of triethylammonium formate in the presence of magnesium for the efficient intermolecular pinacol coupling using MeOH as solvent. Various aromatic carbonyls underwent smooth reductive coupling to give the corresponding 1,2-diols. A series of azo compounds were obtained by the reductive coupling of nitroaromatics while azo compounds were reduced to the corresponding hydrazoarenes by this system. There was no adverse effect on the other reducible and hydrogenolysable groups such as ether linkage, hydroxy and halogens. The reactions are clean, high yielding and inexpensive. All the reactions proceeded smoothly at ambient temperature.
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- Date Issued: 2013
New lives for old: modernity, biomedicine, traditional culture and HIV prevention in Lesotho (a response to Nicola L. Bulled)
- Authors: Vincent, Louise
- Date: 2013
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/141855 , vital:38010 , DOI: 10.1080/23269995.2013.805526
- Description: This is a reply to - Bulled, Nicola L. 2013. “New lives for old: modernity, biomedicine, traditional culture and HIV prevention in Lesotho.” Global Discourse. 3 (2): 284–299. http://0-dx.doi.org.wam.seals.ac.za/10.1080/23269995.2013.804700.
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- Date Issued: 2013
The implementation of a service-learning component in an organic chemistry laboratory course
- Authors: Glover, Sarah R , Sewry, Joyce D , Bromley, Candice L , Davies-Coleman, Michael T , Hlengwa, Amanda I
- Date: 2013
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/70699 , vital:29690 , https://doi.org/10.1021/ed2008153
- Description: Education institutions globally are increasingly expected to explore avenues for the implementation of service-learning into their curricula. A second-year undergraduate organic chemistry laboratory experiment, in which the undergraduate students make azo dyes, can provide a vehicle for a service-learning module in which university undergraduate students then teach students from resource-limited secondary schools how to make azo dyes. Evidence is provided to show how the theory is reinforced for both sets of students through a shared practical experience. The practical application of chemistry is conveyed through the use of the synthetic azo dyes to dye tshirts. The results of this study show that the service-learning experience clearly assists undergraduate students to appreciate the role of chemists in the broader society while at the same time increasing awareness of the inequalities in school education systems.
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- Date Issued: 2013
History of Education: EDB 321
- Authors: Botha, E , Macanda, M A A
- Date: 2012-11
- Subjects: Education
- Language: English
- Type: Examination paper
- Identifier: vital:17343 , http://hdl.handle.net/10353/d1010205
- Description: Examination on History of Education: EDB 321, November 2010.
- Full Text: false
- Date Issued: 2012-11
Academic Practices and Reasoning: APR 111
- Authors: Scott,R , Blatchford, M
- Date: 2012-06
- Language: English
- Type: Examination paper
- Identifier: vital:18270 , http://hdl.handle.net/10353/d1011266
- Description: Academic Practices and Reasoning: APR 111, special examination June 2012.
- Full Text: false
- Date Issued: 2012-06
A qualitative analysis to determine the readiness of rural communities to adopt ICTs: A Siyakhula Living Lab Case Study
- Authors: Gumbo, Sibukelo , Jere, Norbert , Terzoli, Alfredo
- Date: 2012
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/431396 , vital:72771
- Description: Rural schools have a pressing need for ICT and Internet services, for them-selves and the surrounding communities. Educators can play a crucial role of fulfilling this need. But how ready are schools, educators and communi-ties to engage with ICT and use it for their empowerment? This paper re-ports the findings of an e-readiness assessment and promotion drive by re-searchers from the Siyakhula Living Lab in parts of the Mbashe Municipali-ty, in South Africa. The Siyakhula Living Lab is a multi-disciplinary, multi-year initiative to foster grassroots innovation in marginalized communities with the aim of improving their lives and economies. The drive was con-ducted to support the expansion of the network of Digital Access Nodes, ie ICT points-of-presence of the Living Lab in the community: this network rep-resents the structural backbone on which all other activities rest. The as-sessment shows that, while the practical difficulties are many, the communi-ties are very eager to engage with ICT and understand fairly well the con-nection between ICT availability and the possibility of improvement in their life conditions.
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- Date Issued: 2012
A quantitative post-release evaluation of biological control of water lettuce, Pistia stratiotes L. (Araceae) by the weevil Neohydronomus affinis Hustache (Coleoptera: Curculionidae) at Cape Recife Nature Reserve, Eastern Cape Province, South Africa
- Authors: Moore, Gareth R , Hill, Martin P
- Date: 2012
- Language: English
- Type: text , Article
- Identifier: vital:6839 , http://hdl.handle.net/10962/d1010987 , http://dx.doi.org/10.4001/003.020.0217 , https://orcid.org/0000-0003-0579-5298
- Description: [from the introduction] Water lettuce, Pistia stratiotes L. (Araceae) is recognized as being among the world’s worst aquatic weeds. In its adventive range, the plant forms extensive mats capable of blocking navigation channels, impeding water flow in irrigation and flood control canals, and disrupting hydropower generation (Holm et al. 1977). Dense mats of the weed prevent light penetration into the water column which negatively affects submerged aquatic plant communities, causing a lowering of the oxygen concentration and thereby reducing benthic invertebrate and fish populations (Neuenschwander et al. 2009).
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- Date Issued: 2012
An ion-imprinted polymer for the selective extraction of mercury(II) ions in aqueous media
- Authors: Batlokwa, Bareki Shima , Chimuka, Luke , Tshentu, Zenixole R , Cukrowska, Ewa , Torto, Nelson
- Date: 2012
- Language: English
- Type: Article
- Identifier: vital:6566 , http://hdl.handle.net/10962/d1004125
- Description: A double-imprinted polymer exhibiting high sensitivity for mercury(II) in aqueous solution is presented. Polymer particles imprinted with mercury(II) were synthesised by copolymerising the functional and cross-linking monomers, N’–[3– (Trimethoxysilyl)–propyl]diethylenetriamine (TPET) and tetraethylorthosilicate (TEOS). A double-imprinting procedure employing hexadecyltrimethylammonium bromide (CTAB), as a second template to improve the efficiency of the polymer, was adopted. The imprinted polymer was characterised by FTIR, scanning electron microscopy (SEM) and the average size determined by screen analysis using standard test sieves. Relative selective coefficients (k`) of the imprinted polymer evaluated from selective binding studies between Hg2+ and Cu2+ or Hg2+ and Cd2+ were 10 588 and 3 147, respectively. These values indicated highly-favoured Hg2+ extractions over the 2 competing ions. The results of spiked and real water samples showed high extraction efficiencies of Hg2+ ions, (over 84%) as evaluated from the detected unextracted Hg2+ ions by ICP-OES. The method exhibited a dynamic response concentration range for Hg2+ between 0.01 and 20 μg/mℓ, with a detection limit (LOD, 3σ) of 0.000036 μg/mℓ (36 ng/ℓ) that meets the monitoring requirements for the USA EPA of 2 000 ng/ℓ for Hg2+ in drinking water. Generally, the data (n=10) had percentage relative standard deviations (%RSD) of less than 4%. Satisfactory results were also obtained when the prepared sorbent was applied for the pre-concentration of Hg2+ from an aqueous certified reference material. These findings indicate that the double-imprinted polymer has potential to be used as an efficient extraction material for the selective pre–concentration of mercury(II) ions in aqueous environments.
- Full Text:
- Date Issued: 2012
Cooperative wasp-killing by mixed-species colonies of honeybees, Apis cerana and Apis mellifera
- Authors: Tan, K , Yang, M-Y , Li, H , Zhang, Z-L , Radloff, Sarah E , Hepburn, H Randall
- Date: 2012
- Language: English
- Type: text , Article
- Identifier: vital:6838 , http://hdl.handle.net/10962/d1010979 , http://dx.doi.org/10.1007/s13592-011-0098-5
- Description: The cooperative defensive behaviour of mixed-species colonies of honeybees, Apis cerana and Apis mellifera, were tested against a predatory wasp, Vespa velutina. When vespine wasps hawk honeybees at their nest entrances, the difference in the numbers of bees involved in heat-balling among pure species and mixed-species colonies was not significantly different. However, in the mixed colonies, the numbers of A. cerana and A. mellifera workers involved in heat-balling were significantly different. The duration of heat-balling among these three groups was significantly different. During heat-balling, guard bees of both species in mixed colonies raised their thoracic temperatures and the core temperatures of the heat-balls were about 45°C, which is not significantly different from that of the pure species. These results suggest that the two species of honeybees can cooperate in joint heat-balling against the wasps, but A. cerana was more assertive in such defence.
- Full Text: false
- Date Issued: 2012
Linking teaching and research: an alternative perspective?
- Authors: Boughey, Chrissie M
- Date: 2012
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/483230 , vital:78734 , https://doi.org/10.1080/13562517.2012.725528
- Description: How do universities, and the academics who work in them, understand the relationship between teaching and research? In several countries, acknowledgement of the need to link teaching and research has led to the development of institutional strategies to achieve this goal (see Jenkins and Healey Citation2005, for an overview of work in the UK). In South Africa, the linking of teaching and research has become significant because of debates about differentiation in a system which continues to be structured by its apartheid past. About 5 of the 23 public universities produce the bulk of research and postgraduate outputs (ASSAf Citation2010) whilst the rest focus mainly on undergraduate teaching. Funding favours research, however, and many universities are seeking to increase research outputs although the need for quality teaching at undergraduate level remains paramount given low participation and success rates amongst black students.
- Full Text:
- Date Issued: 2012
Mitochondrial DNA paradox: sex-specific genetic structure in a marine mussel despite maternal inheritance and passive dispersal
- Authors: Teske, Peter R , Papadopoulos, Isabelle , Barker, Nigel P , McQuaid, Christopher D
- Date: 2012
- Language: English
- Type: Article
- Identifier: vital:6836 , http://hdl.handle.net/10962/d1010959
- Description: Background: When genetic structure is identified using mitochondrial DNA (mtDNA), but no structure is identified using biparentally-inherited nuclear DNA, the discordance is often attributed to differences in dispersal potential between the sexes. Results: We sampled the intertidal rocky shore mussel Perna perna in a South African bay and along the nearby open coast, and sequenced maternally-inherited mtDNA (there is no evidence for paternally-inherited mtDNA in this species) and a biparentally-inherited marker. By treating males and females as different populations, we identified significant genetic structure on the basis of mtDNA data in the females only. Conclusions: This is the first study to report sex-specific differences in genetic structure based on matrilineally-inherited mtDNA in a passively dispersing species that lacks social structure or sexual dimorphism. The observed pattern most likely stems from females being more vulnerable to selection in habitats from which they did not originate, which also manifests itself in a male-biased sex ratio. Our results have three important implications for the interpretation of population genetic data. First, even when mtDNA is inherited exclusively in the female line, it also contains information about males. For that reason, using it to identify sex-specific differences in genetic structure by contrasting it with biparentally-inherited markers is problematic. Second, the fact that sex-specific differences were found in a passively dispersing species in which sex-biased dispersal is unlikely highlights the fact that significant genetic structure is not necessarily a function of low dispersal potential or physical barriers. Third, even though mtDNA is typically used to study historical demographic processes, it also contains information about contemporary processes. Higher survival rates of males in non-native habitats can erase the genetic structure present in their mothers within a single generation.
- Full Text:
- Date Issued: 2012
Network telescope metrics
- Authors: Irwin, Barry V W
- Date: 2012
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/427944 , vital:72475 , https://www.researchgate.net/profile/Barry-Ir-win/publication/265121268_Network_Telescope_Metrics/links/58e23f70a6fdcc41bf973e69/Network-Telescope-Metrics.pdf
- Description: Network telescopes are a means of passive network monitoring, increasingly being used as part of a holistic network security program. One problem encountered by researchers in the sharing of the collected data form these systems. This is either due to the size of the data, or possibly a need to maintain the privacy of the Network address space being used for monitoring. This paper proposes a selection of metrics which can be used to communicate the most salient information contained in the data-set with other researchers, without the need to exchange or disclose the data-sets. Descriptive metrics for the sensor system are discussed along with numerical analysis data. The case for the use of graphical summary data is also presented.
- Full Text:
- Date Issued: 2012
The distribution, habitat, diet and forensic significance of the scarab Frankenbergerius forcipatus (Harold, 1881) (Coleoptera : Scarabaeidae)
- Authors: Midgley, John M , Collett, Isabel J , Villet, Martin H
- Date: 2012
- Language: English
- Type: Article
- Identifier: vital:6842 , http://hdl.handle.net/10962/d1010992
- Description: Records of African beetles feeding on carrion are scattered and incomplete, but important to forensic entomology. Thirty-three specimens of Frankenbergerius forcipatus (Harold, 1881) were found on carrionnear Grahamstown, Eastern Cape, South Africa, providing new insight into the distribution (hills and mountains), habitat (fynbos and forest), biology (generalist on decaying material) and forensic significance (wet-decay, late opportunist) of the species.
- Full Text:
- Date Issued: 2012
Visualization of C Data Structures for Novice Programmers
- Authors: Van der Merwe, Dylan , Bradshaw, Karen L
- Date: 2012
- Subjects: To be catalogued
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10962/477133 , vital:78048 , ISBN 9780620536103
- Description: The adage “a picture is worth a thousand words” is true in many contexts, including understanding programming concepts. We have developed an IDE, consisting of a parser, interpreter and visualizer, for a subset of the C Programming Language to facilitate the teaching and learning of data structures and memory management in the language. Utilizing a visual system to create an immersive application for novice C programmers, has been shown to lead to faster comprehension of the programming concepts, as well as greater familiarity with the vocabulary of the programming terms.
- Full Text:
- Date Issued: 2012
Academic Practices and Reasoning: APR 122
- Authors: Scott, R , Blatchford, M
- Date: 2012-01
- Language: English
- Type: Examination paper
- Identifier: vital:18252 , http://hdl.handle.net/10353/d1011246
- Description: Academic Practices and Reasoning: APR 122, supplementary examination January 2012.
- Full Text: false
- Date Issued: 2012-01
Data Structures and Algorithms: CSC 223
- Authors: Scott, M S , Sibanda, K
- Date: 2012-01
- Language: English
- Type: Examination paper
- Identifier: vital:17761 , http://hdl.handle.net/10353/d1010294
- Description: Data Structures and Algorithms: CSC 223, degree examinations January 2012.
- Full Text: false
- Date Issued: 2012-01
Psychopathology and Counselling Psychology: PSY 311
- Authors: Sandlana, N S , Marais, R , Young, C
- Date: 2012-01
- Language: English
- Type: Examination paper
- Identifier: vital:18016 , http://hdl.handle.net/10353/d1010593
- Description: Psychopathology and Counselling Psychology: PSY 311, special examination January 2012.
- Full Text: false
- Date Issued: 2012-01