List of Titles

Rapid bioassessment of the effects of repeated rotenone treatments on invertebrate assemblages in the Rondegat River, South Africa

- Bellingan, Terence A, Woodford, Darragh J, Gouws, Jeanne, Villet, Martin H, Weyl, Olaf L F

Authors: Bellingan, Terence A , Woodford, Darragh J , Gouws, Jeanne , Villet, Martin H , Weyl, Olaf L F
Date: 2015
Subjects: To be catalogued
Language: English
Type: text , article
Identifier: http://hdl.handle.net/10962/442279 , vital:73972 , https://doi.org/10.2989/16085914.2014.984651
Description: The potential collateral effects of eradicating invasive fishes in streams necessitate the monitoring of invertebrate communities during treatment. In an environmental rehabilitation programme, non-native smallmouth bass were removed from the lower reaches of the Rondegat River, Western Cape, South Africa, in 2012 and again in 2013 using the piscicide rotenone. A monitoring programme tracked the ecological response of organisms to these activities using quantitative sampling of macroinvertebrates on stones and the ISO-certified SASS5 rapid bioassessment method for assessing macroinvertebrate community integrity. We recorded a significant decrease in macroinvertebrate densities from the stones-in-current biotope following both rotenone treatments. The average score per taxon (ASPT) declined after the first treatment, indicating a loss of taxa sensitive to diminished water quality, then recovered prior to the second treatment, and subsequently no decline was detected after the lower dose used in the 2013 treatment. The SASS values were too variable to reveal trends. The ASPTs indicated that the community may have been resistant to low dose and resilient to high dose, due to inter-treatment recovery following the 2012 treatment, suggesting that the invertebrate assemblage is resilient to the conservative use of rotenone for localised river rehabilitation when upstream sources of recruitment exist.
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Date Issued: 2015

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The nursery role of a sheltered surf-zone in warm-temperate southern Africa

- Rishworth, Gavin M, Strydom, Nadine A, Potts, Warren M

Authors: Rishworth, Gavin M , Strydom, Nadine A , Potts, Warren M
Date: 2015
Subjects: To be catalogued
Language: English
Type: text , article
Identifier: http://hdl.handle.net/10962/443651 , vital:74141 , https://hdl.handle.net/10520/EJC177697
Description: Marine fish nurseries such as surf-zones have usually been classified as nurseries based solely on the density of pre-adult fish, yet the full suite of developmental stages are seldom assessed because of difficulties associated with sampling these habitats. The larval and early juvenile fish assemblage was studied in a sheltered surf-zone (King's Beach, South Africa), where high densities of older juveniles are known to occur. Fishes were collected fortnightly over six months using two modified seine nets. Although the surf composition included typical species for this habitat type, Gobiidae, Gobiesocidae and Haemulidae dominated the larval assemblage, which suggested that the nearby rocky structure and estuaries have an influence on the assemblage. Three species, Liza richardsonii (Mugilidae), Pomadasys olivaceus (Haemulidae) and Diplodus capensis (Sparidae), showed evidence of growth and recruitment into the surf-zone from the late larval stage. The high density of larval and juvenile fishes, the presence of more than one early life history stage and the observed growth of fishes suggests that King's Beach provides a suitable nursery habitat for several fishes.
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Date Issued: 2015

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The relationship between concurrently measured SASS (South African Scoring System) and turbidity data archived in the South African River Health Programme’s Rivers Database

- Gordon, Andrew K, Griffin, Neil J, Palmer, Carolyn G

Authors: Gordon, Andrew K , Griffin, Neil J , Palmer, Carolyn G
Date: 2015
Language: English
Type: text , Article
Identifier: vital:7098 , http://hdl.handle.net/10962/d1015956
Description: The need for monitoring the biological impacts of instream sediments has long been recognised, yet robust and scientifically defensible tools for doing so are still in the early stages of development because of the difficulties experienced by researchers in characterising the complicated mechanisms of biological effect elicited by sediment particles. Biological monitoring is one such tool, and this paper reports on the initial stages of a study to determine the most applicable approach for measuring the effects of instream sediments on aquatic macroinvertebrates in the South African context. In this first instance, the suitability of the rapid macroinvertebrate biomonitoring tool (the South African Scoring System) was investigated by determining the extent of the correlation between concurrently measured SASS metrics and turbidity data collected for the South African River Health Programme. All three SASS metrics – SASS score, number of taxa (NOT), and average score per taxon (ASPT) – were found to be significantly negatively correlated with turbidity, although variation in the data was high. Turbidity was found to be the major driver of change in ASPT. In contrast, electrical conductivity was the major driver of SASS scores and NOT, with turbidity a close second. When combined, electrical conductivity and turbidity accounted for 80 percent (SASS score) and 75 percent (NOT) of the variation in the regression model. Consequently, SASS metrics are a crude, but reliable, indicator of the negative biological implications of excessive instream sedimentation as measured by turbidity. A number of other potential biomonitoring approaches for detecting the impacts of fine sediment exposure are identified for further investigation: spatial analyses of macroinvertebrate assemblages; and the use of structural and functional metrics.
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Date Issued: 2015

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Interactive efficacies of Elephantorrhiza elephantina and Pentanisia prunelloides extracts and isolated compounds against gastrointestinal bacteria

- Mpofu, Smart J, Olivier, Denise K, Krause, Rui W M, Ndinteh, Derek T, Van Vuuren, S

Authors: Mpofu, Smart J , Olivier, Denise K , Krause, Rui W M , Ndinteh, Derek T , Van Vuuren, S
Date: 2014
Language: English
Type: text , article
Identifier: http://hdl.handle.net/10962/124122 , vital:35552 , https://doi.org/10.1016/j.sajb.2014.07.002
Description: Elephantorrhiza elephantina (Burch.) Skeels (Fabaceae) and Pentanisia prunelloides (Klotzsch ex Eckl. & Zeyh.) Walp. (Rubiaceae) are two medicinal plants used extensively in southern Africa to treat various ailments. Often, decoctions and infusions from these two plants are used in combination specifically for stomach ailments. The antimicrobial activities of the methanol and aqueous extracts of the rhizomes of the two plants, as well as the two active ingredients from the plants [(−)-epicatechin and palmitic acid] have been determined apart and in combination against Enterococcus faecalis (ATCC 29212), Escherichia coli (ATCC 8739) and Bacillus cereus (ATCC 11778). The minimum inhibitory concentration (MIC) values for the aqueous (0.50–16.00 mg/mL) and methanol (0.20–16.00 mg/mL) extracts independently demonstrated varied efficacies depending on the pathogen of study. When the two plants were combined in 1:1 ratios, synergistic to additive interactions (ΣFIC values 0.19–1.00) were noted. Efficacy for the two major compounds ranged between 0.13–0.63 mg/mL and mainly synergistic interactions were noted against E. faecalis and E. coli. The predominantly synergistic interactions noted between E. elephantina and P. prunelloides and major compounds, when tested in various ratios against these pathogens, provide some validation as to the traditional use of these two plants to treat bacterial gastrointestinal infections.
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Date Issued: 2014

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Kalaharituber pfeilii and associated bacterial interactions

- Adeleke, Rasheed, Dames, Joanna F

Authors: Adeleke, Rasheed , Dames, Joanna F
Date: 2014
Subjects: To be catalogued
Language: English
Type: text , article
Identifier: http://hdl.handle.net/10962/440490 , vital:73787 , https://doi.org/10.1016/j.sajb.2013.10.003
Description: Truffles are generally known to form a mycorrhizal relationship with plants. Kalaharituber pfeilii (Hennings) Trappe and Kagan-Zur is a species of desert truffle that is found in the southern part of Africa. The life cycle of this truffle has not been fully investigated as there are many unconfirmed plant species that have been suggested as potential hosts. Many mycorrhizal associations often involve other role players such as associated bacteria that may influence the establishment of the mycorrhizal formation and function. As part of an effort to understand the life cycle of K. pfeilii, laboratory experiments were conducted to investigate the role of ascocarp associated bacteria. Bacterial isolates obtained from the truffle ascocarps were subjected to microbiological and biochemical tests to determine their potentials as mycorrhizal helper bacteria. Tests conducted included stimulation of mycelial growth in vitro, indole acetic acid (IAA) production and phosphate solubilising. A total of 17 bacterial strains belonging to the Proteobacteria, Firmicutes and Actinobacteria were isolated from the truffle ascocarps and identified with sequence homology and phylogenetic methods. Three of these isolates showed potential to be helper bacteria in at least one of the media tested through the stimulation of mycelial growth. Furthermore, four isolates produced IAA and one was able to solubilise CaHPO3 in vitro. One isolate, identified as a relative of Paenibacillus sp. stimulated mycelial growth on all the media tested. Other bacterial isolates that showed potential stimulation of mycelial growth were identified molecularly as a Bacillus sp. and two strains of Rhizobium sp. This study has contributed to the existing knowledge on the biotic interactions with K. pfeilii which may be useful in further symbiont and re-synthesis investigations.
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Date Issued: 2014

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Nectar feeding by weavers (Ploceidae) and their role as pollinators

- Craig, Adrian J F K

Authors: Craig, Adrian J F K
Date: 2014
Subjects: To be catalogued
Language: English
Type: text , article
Identifier: http://hdl.handle.net/10962/449445 , vital:74822 , https://doi.org/10.2989/00306525.2014.900828
Description: Reviews of nectar-feeding by birds initially focused on specialist nectarivores and ignored the role that more generalist feeders may play in plant pollination. Recent work has emphasised the range of bird species, both specialist and opportunistic, that feed on nectar. In this review, I collate published information on nectar-feeding by weavers, highlight known weaver–plant relationships, and suggest areas for future research. There are published records of nectar feeding for Plocepasser superciliosus, Amblyospiza albifrons, Anaplectes rubriceps, two Quelea spp., four Euplectes spp., all six Foudia spp., two Malimbus spp. and 22 Ploceus spp. To date, there have been no unambiguous reports of other genera feeding on nectar. The role of Ploceus species as pollinators of Strelitzia reginae, proposed by ornithologists decades ago, has recently been confirmed by botanists. Current studies of Aloe species in South Africa suggest that opportunistic avian nectarivores such as ploceids may be the chief pollinators of bird-pollinated plants in this genus, whereas specialist nectar feeders (sunbirds) may be ‘nectar robbers’ in many cases. Particularly for winter-flowering plants, weaver species are potential pollinators, but exclusion experiments are needed to establish their role, while the dietary importance of nectar, and its impact on the birds’ physiology, has not been critically studied.
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Date Issued: 2014

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Real-time monitoring of 3T3-L1 preadipocyte differentiation using a commercially available electric cell-substrate impedance sensor system:

- Kramer, Adam H, Joos-Vandewalle, Julia, Edkins, Adrienne L, Frost, Carminita L, Prinsloo, Earl

Authors: Kramer, Adam H , Joos-Vandewalle, Julia , Edkins, Adrienne L , Frost, Carminita L , Prinsloo, Earl
Date: 2014
Language: English
Type: text , article
Identifier: http://hdl.handle.net/10962/164830 , vital:41176 , DOI: 10.1016/j.bbrc.2013.12.123
Description: Real-time analysis offers multiple benefits over traditional end point assays. Here, we present a method of monitoring the optimisation of the growth and differentiation of murine 3T3-L1 preadipocytes to adipocytes using the commercially available ACEA xCELLigence Real-Time Cell Analyser Single Plate (RTCA SP) system. Our findings indicate that the ACEA xCELLigence RTCA SP can reproducibly monitor the primary morphological changes in pre- and post-confluent 3T3-L1 fibroblasts induced to differentiate using insulin, dexamethasone, 3-isobutyl-1-methylxanthine and rosiglitazone; and may be a viable primary method of screening compounds for adipogenic factors.
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Date Issued: 2014

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Sanitation policy and prevention of environmental contamination in South Africa

- Hoossein, Shafick, Whittington-Jones, Kevin J, Tandlich, Roman

Authors: Hoossein, Shafick , Whittington-Jones, Kevin J , Tandlich, Roman
Date: 2014
Language: English
Type: text , article
Identifier: http://hdl.handle.net/10962/76834 , vital:30628 , DOI:10.30638/eemj.2014.141
Description: Prior to 1994, 21 million people were without access to sanitation in South Africa. Progress towards the backlog elimination started after 1994, but was slow-paced. From 1994 until 2011, the sanitation backlog has been decreased by between 29.8 and 79.2 % from the 1994 levels, depending on the province. Mechanisms were created for implementation of sanitation projects, but this was marginally successful and risk of environmental pollution from sanitation persisted. The period between 2009 and present day seemed to have brought on a significant fast-tracking of sanitation project around South Africa. This coincides with the transfer of oversight and partial implementation responsibility to the Department of Human Settlement and the launch of the Rural Household Infrastructure Programme. It also originated from the integrated programmes which drew in input from all stakeholders at the national and local government levels. Limitations still exist in maintenance and sanitation skills’ portfolio of some local municipalities, mainly in the Eastern Cape and Limpopo Province. However, the present status is still in partial conflict with government aims, legislation and policies. Novel tools such as the Technology Assessment and the Environmental Technology Assessment will have to be implemented in the sanitation decision-making and the novel strategies for skills development will have to be devised. If sufficient maintenance skills are developed in a local municipal area, then this will prevent negative environmental effects and results in lowered sanitation-related environmental contamination. Improvement in can be expected from the new national Department of Water Affairs and Sanitation.
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Date Issued: 2014

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Testing antivirus engines to determine their effectiveness as a security layer

- Haffejee, Jameel, Irwin, Barry V W

Authors: Haffejee, Jameel , Irwin, Barry V W
Date: 2014
Subjects: To be catalogued
Language: English
Type: text , article
Identifier: http://hdl.handle.net/10962/429673 , vital:72631 , 10.1109/ISSA.2014.6950496
Description: This research has been undertaken to empirically test the assumption that it is trivial to bypass an antivirus application and to gauge the effectiveness of antivirus engines when faced with a number of known evasion techniques. A known malicious binary was combined with evasion techniques and deployed against several antivirus engines to test their detection ability. The research also documents the process of setting up an environment for testing antivirus engines as well as building the evasion techniques used in the tests. This environment facilitated the empirical testing that was needed to determine if the assumption that antivirus security controls could easily be bypassed. The results of the empirical tests are also presented in this research and demonstrate that it is indeed within reason that an attacker can evade multiple antivirus engines without much effort. As such while an antivirus application is useful for protecting against known threats, it does not work as effectively against unknown threats.
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Date Issued: 2014

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The diet of the calanoid copepod, Pseudodiaptomus hessei, in a permanently open southern African estuary inferred from fatty acid analyses

- Noyon, Margaux, Froneman, P William

Authors: Noyon, Margaux , Froneman, P William
Date: 2014
Language: English
Type: text , article
Identifier: http://hdl.handle.net/10962/70901 , vital:29758 , https://doi.org/10.1093/plankt/fbu037
Description: The fatty acid (FA) composition of Pseudodiaptomus hessei, one of the most abundant copepod species in southern African estuaries and lakes, reveals potential food selectivity and the importance of flagellate prey in their diets. Differences in FA profiles between males and females were recorded; however, none of these patterns matched the reproductive activities of the copepod. Our findings stress the importance of improving our knowledge of FA biosynthesis pathways to employ fatty acids as trophic markers in feeding studies of zooplankton in temperate environments.
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Date Issued: 2014

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Towards a platform to visualize the state of South Africa's information security

- Swart, Ignus, Irwin, Barry V W, Grobler, Marthie

Authors: Swart, Ignus , Irwin, Barry V W , Grobler, Marthie
Date: 2014
Subjects: To be catalogued
Language: English
Type: text , article
Identifier: http://hdl.handle.net/10962/429688 , vital:72632 , 10.1109/ISSA.2014.6950511
Description: Attacks via the Internet infrastructure is increasingly becoming a daily occurrence and South Africa is no exception. In response, certain governments have published strategies pertaining to information security on a national level. These policies aim to ensure that critical infrastructure is protected, and that there is a move towards a greater state of information security readiness. This is also the case for South Africa where a variety of policy initiatives have started to gain momentum. While establishing strategy and policy is essential, ensuring its implementation is often difficult and dependent on the availability of resources. This is even more so in the case of information security since virtually all standardized security improvement processes start off with specifying that a proper inventory is required of all hardware, software, people and processes. While this may be possible to achieve at an organizational level, it is far more challenging on a national level. In this paper, the authors examine the possibility of making use of available data sources to achieve inventory of infrastructure on a national level and to visualize the state of a country's information security in at least a partial manner.
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Date Issued: 2014

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A kernel-driven framework for high performance internet routing simulation

- Herbert, Alan, Irwin, Barry V W

Authors: Herbert, Alan , Irwin, Barry V W
Date: 2013
Subjects: To be catalogued
Language: English
Type: text , article
Identifier: http://hdl.handle.net/10962/429585 , vital:72624 , 10.1109/ISSA.2013.6641048
Description: The ability to provide the simulation of packets traversing an internet path is an integral part of providing realistic simulations for network training, and cyber defence exercises. This paper builds on previous work, and considers an in-kernel approach to solving the routing simulation problem. The inkernel approach is anticipated to allow the framework to be able to achieve throughput rates of 1GB/s or higher using commodity hardware. Processes that run outside the context of the kernel of most operating system require context switching to access hardware and kernel modules. This leads to considerable delays in the processes, such as network simulators, that frequently access hardware such as hard disk accesses and network packet handling. To mitigate this problem, as experienced with earlier implementations, this research looks towards implementing a kernel module to handle network routing and simulation within a UNIX based system. This would remove delays incurred from context switching and allows for direct access to the hardware components of the host.
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Date Issued: 2013

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Deep Routing Simulation

- Irwin, Barry V W, Herbert, Alan

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.
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Date Issued: 2013

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E-skills training on communal, fixed infrastructure as an activator of personal use of mobile internet

- Gumbo, Sibukelo, Terzoli, Alfredo

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.
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Date Issued: 2013

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Finding the best clay: experiences of rural potter Alice Gqa Nongebeza contextualised

- Steele, John

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

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Mg/Triethylammonium Formate: A Useful System for Reductive Dimerization of Araldehydes into Pinacols;Nitroarenes into Azoarenes and Azoarenes into Hydrazoarenes

- Pamar, M Geeter, Govender, P, Muthusamy, K, Krause, Rui W M

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

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The implementation of a service-learning component in an organic chemistry laboratory course

- Glover, Sarah R, Sewry, Joyce D, Bromley, Candice L, Davies-Coleman, Michael T, Hlengwa, Amanda I

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

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