A histological description of ovarian recrudescence in two Labeo victorianus populations
- Authors: Booth, Anthony J , Hecht, Thomas
- Date: 2010
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/123564 , vital:35455 , https://doi.org/10.2989/16085910409503813
- Description: The ovaries of Labeo victorianus are paired organs situated in the peritoneal cavity and suspended on either side of the midline by a mesovarium. A capsule, composed of dense, regularly-arranged collagen and elastic fibres mixed with a few smooth muscle cells, enclosed the ovaries and gave off connective tissue septa, forming the ovigerous lamellae, which contained germ and follicle cells. Eight discrete stages of recrudescence were identified: oogonia, chromatin nucleolar oocytes, perinucleolar oocytes, primary yolk vesicle oocytes, secondary yolk vesicle oocytes, tertiary yolk vesicle oocytes, post-ovulatory follicles and atretic oocytes. Ovulation seemed to be synchronised with the onset of rainfall, with some deviations in the Sio River population. Gonadosomatic index variation followed a bimodal pattern, with maxima between January–February and between September–October for both populations. The same pattern was exhibited for both rainfall and water levels at the two study sites. Successful ovulation was followed by the formation of post-ovulatory follicles and Type I atresia, while failed spawning was characterised by Type II atresia. Clearance of post-ovulatory follicles was by phagocytosis and formation of melanomacrophage centres. There were variations in post-ovulatory changes between the two populations. Reproductive patterns in the Kagera River population conformed to the ‘norm’ in African labeines of the synchronisation of spawning with rainfall. Slight deviations from this pattern were, however, observed in the Sio River population where spawning occurred prior to the onset of rainfall.
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An assessment of a light-attraction fishery in southern Lake Malawi
- Authors: Weyl, Olaf L F , Kazembe, Jacqueline , Booth, Anthony J , Mandere, D S
- Date: 2010
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/123683 , vital:35472 , https://doi.org/10.2989/16085910409503787
- Description: This study provides the first quantitative assessment of the light-attraction component of a small-scale purse seine, locally known as a chilimira net, fishery in two areas of southern Lake Malawi. For monitoring purposes the shoreline of Lake Malawi is divided into a number of statistical strata. Two strata (‘2.1’ in the southeast arm and ‘3.1’ in the southwest arm of the lake) were selected for this study. Catch per unit effort in stratum 2.1 was generally lower than that recorded in stratum 3.1 but nets in stratum 2.1 fished more frequently, leading to similar annual catches in the two strata. Annual catch was estimated as 19.4 (CI = 15.9–23.5) tons net–1 year–1 in stratum 2.1 and 23.5 (CI = 19.5–28.1) tons net–1 year–1 in stratum 3.1 respectively. A total of 62 species from 28 cichlid genera, and 13 species from nine non-cichlid genera, were identified from the samples. Of the 37 genera identified, only five; Copadichromis, Dimidiochromis, Engraulicypris, Oreochromis and Rhamphochromis, contributed more than 5% to the total annual catch in either stratum. Their combined contribution to the annual catch was in excess of 85% in both strata. Comparisons showed that catch-composition was dependent on area. Length-frequency distributions of major target species in the catch showed that the fishery targeted juveniles in stratum 2.1, while in stratum 3.1 most individuals were harvested after reaching their lengthat-maturity. The dependence of catch-composition and size-selection on area indicates that management interventions for this fishery need to be area-specific. Since the fishery targets a diverse species assemblage, effort limitation or area closure may be the only viable management options, until such time as additional biological and fisheries data are available for the application of stock assessment models.
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More media for Southern Africa?: the place of politics, economics and convergence in developing media density
- Authors: Berger, Guy
- Date: 2007
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/147825 , vital:38676 , https://0-doi.org.wam.seals.ac.za/10.1080/02560240485310041
- Description: In line with global trends, media in Southern Africa in the past decade has been moving slowly towards mergers, partnerships and multi-platform publishing. Driven by politics and facilitated by technology, the process has had to confront the difficulty of establishing viable economic models, the lack of regional integration within Southern African countries, and what is sometimes a difficult political environment. Markets remain largely national or local and economically weak. Print media faces huge hurdles. Broadcast media density is improving, partly through noncommercial mechanisms. News websites are understaffed, lacking in viable survival strategies and skills, and are incompletely integrated with parent media platforms. Economic pressures, however, are likely to force Southern African media operations into greater synergies in search of survival. The various convergences entailed may increase media density.
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Transforming the media: a cultural approach
- Authors: Steenveld, Lynette N
- Date: 2007
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/147891 , vital:38682 , DOI: 10.1080/02560240485310061
- Description: The change from an Apartheid state to a liberal democratic one has wrought many changes at all levels of South African society: the economic, social, political, cultural. This paper explores the impacts of these changes on the South African print media industry, with a view to assessing their contribution to the development of a democratic citizenship. While acknowledging the constraining effects of economic structures of ownership, the paper locates these within the broader social and political context of post-apartheid South Africa. It thus attempts to synthesise elements of both a political economy and cultural approach to the analysis of cultural production.
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"My novel, Hill of Fools"
- Authors: Peteni, R L , Wright, Laurence
- Date: 2004
- Language: English
- Type: text , article
- Identifier: vital:7038 , http://hdl.handle.net/10962/d1007376 , http://hdl.handle.net/10520/EJC47869
- Description: preprint , R.L. Peteni - 'There is a tendency in human beings to pay no heed to events in small remote areas. They would rather concern themselves only with those events which make headlines, with political upheavals and industrial conflicts centred in large metropolitan regions. Yet there is always drama and human conflict in the humblest rural village. In selecting a pastoral theme and small fictitious villages in an obscure corner of Keiskammahoek as the setting of the novel, I had an ironic intention. Themes illustrated in these obscure villages would, I believed, have more universal application than they would if I had selected a larger centre, identifiable personages and known political trends. I did not want anybody to sit back, complacent, feeling that the spotlight was on Lennox Sebe’s Ciskei alone, or Kaiser Matanzima’s Transkei, or John Vorster’s apartheid South Africa. The spotlight is on the Ciskei, yes, on Transkei, on South Africa, on any other country where public life and personal relationships are bedevilled by tribalism or racialism or any form of sectionalism.
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A comparison of the Linux and Windows device driver architectures
- Authors: Tsegaye, Melekam , Foss, Richard
- Date: 2004
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/427198 , vital:72421 , https://dl.acm.org/doi/pdf/10.1145/991130.991132
- Description: In this paper the device driver architectures currently used by two of the most popular operating systems, Linux and Microsoft's Windows, are examined. Driver components required when implementing device drivers for each operating system are presented and compared. The process of implementing a driver, for each operating system, that performs I/O to a kernel buffer is also presented. The paper concludes by examining the device driver development environments and facilities provided to developers by each operating system.
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A new broom: feature
- Authors: Cocks, Michelle L , Dold, Anthony P , Sizane, Nomtunzi
- Date: 2004
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/141404 , vital:37969 , https://hdl.handle.net/10520/EJC112779
- Description: Traditional grass brooms keep certain cultural practices alive in urban areas and provide rural people with a means to earn an income.
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A Unified Architecture For Automatic Software Updates
- Authors: White, Dominic , Irwin, Barry V W
- Date: 2004
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/428800 , vital:72537 , https://citeseerx.ist.psu.edu/document?repid=rep1type=pdfdoi=6e1cd9269a0c5532faf7a23f82995fcfa39e59bd
- Description: This paper attempts to address the issue of hardening the internal secu-rity of an organisation’s network by easing its patch management. Tradi-tionally security has been modeled on a" hard outer shell" approach, with a firewall protecting the otherwise vulnerable internal network. With the advent of worms using such techniques as social engineering to by-pass the organisational firewall and installing trojans, this approach is no longer sufficient. As a result of these new attacks, emphasis should be placed on improving the security of the internal network. Most research agrees that prompt patching of security vulnerabilities would significantly reduce the vulnerability of these machines. However, this requires sys-tem administrators not only to keep abreast of the flood of patches, but to ensure they are deployed to every machine, in what could be a very large network. These difficulties are worsened by problems the patches themselves often create. This is a difficult task and the failure of system administrators to perform it is echoed in the recent spate of worm at-tacks, with some taking advantage of vulnerabilities for which patches had been released up to six months earlier.
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A unified patch management architecture
- Authors: White, Dominic , Irwin, Barry V W
- Date: 2004
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/428312 , vital:72502 , https://d1wqtxts1xzle7.cloudfront.net/49200003/A_Unified_Patch_Management_Architecture20160928-23008-tl6zi6-libre.pdf?1475130102=andresponse-content-disposi-tion=inline;+filename=A_Unified_Patch_Management_Architecture.pdfandExpires=1714792674andSignature=JMVkFUbxZO5SzFTdhoeVBJk99hD~p5HQhSlLP0sgvU6p6hRRILz8dWwB9M1OPLXDnqYG3RLWyomwNweZtQpFuFwMgyx-EV~7TA0wkCAfzQr0N9YoOjbwcbHA5Fse1c3zFw7rtpwUYoEPyO17TWplLI7IkVArlotnG~3AWf1AKVmhWQ2gvfXAEi361XRwOFlC1d2XLiKQhVTafh7OrAuGt7EDUKuczw1K4u7YZxi5I7ty~704aTvILlKoVkBpVnYC1U3sVmj8BixFhY84MYD~YvM6ym3bVkitE1iDrpFjH40nR8QF5jpkOurB~aikFgNmB1WNXo8kHbyRAjciZQOYhOg__andKey-Pair-Id=APKAJLOHF5GGSLRBV4ZA
- Description: This paper attempts to address the issue of harden-ing the internal security of an organisation’s network by easing its patch management. A unified architecture to aid with this process is proposed, with the view towards the implementation of an open source, cross platform tool to solve this problem.
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Additional morphological characteristics of Olive Thrushes and Karoo Thrushes
- Authors: Bonnevie, Bo T , Craig, Adrian J F K , Hulley, Patrick E
- Date: 2004
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/447712 , vital:74669 , https://www.tandfonline.com/doi/pdf/10.2989/00306520409485415
- Description: A southern race of the Olive Thrush, Turdus olivaceus smithi Bonaparte, has recently been proposed as a full species, the Karoo Thrush Turdus smithi (Bowie et al. 2003). Some of the published information on the Olive Thrush Turdus olivaceus olivaceus thus pertains to the Karoo Thrush (eg Kopij 2000), whereas other information deals specifically with the Olive Thrush (eg Winterbottom 1966, Bonnevie et al. 2003). We have ringed, recaptured and recovered both Olive and Karoo Thrushes in the Eastern Cape since 1986, and the two taxa are markedly different in this region. We describe some differences in appearance of the two populations from these data, and compare mass and wing length of living birds, as well as culmen and tarsus lengths of museum specimens from the East London Museum, South Africa. The collection sites of the museum specimens were mapped using ArcView 3.1 (ESRI 1996) together with the ringing sites (Figure 1). Areas of potential sympatry are Oudtshoorn (33 25’S, 22 11’E) and Patensie (33 45’S, 24 48’E).
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An email based issue-tracking workflow system that is extensible across organizational boundaries
- Authors: Kwinana, Z N , Wentworth, Peter N , Terzoli, Alfredo
- Date: 2004
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/427517 , vital:72444 , https://www.researchgate.net/profile/Alfredo-Terzoli/publication/267848658_AN_EMAIL_BASED_ISSUE-TRACK-ING_WORKFLOW_SYSTEM_THAT_IS_EXTENSIBLE_ACROSS_ORGANIZATIONAL_BOUNDARIES/links/5523cb990cf2b351d9c338cb/AN-EMAIL-BASED-ISSUE-TRACKING-WORKFLOW-SYSTEM-THAT-IS-EXTENSIBLE-ACROSS-ORGANIZATIONAL-BOUNDARIES.pdf
- Description: There is a demand for improved communication and efficiency within the work place. As emails are generally used more than issue tracking systems, this paper will investigate a way of integrating the main fea-tures of email with those of an issue tracking system to ensure tasks are completed and if not information is provided to the relevant people at the relevant times. This will be done by creating an issue in an issue tracking system that is linkable to an email so as to track tasks that need to be done and follow the task through until completion.
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An introduction: Peteni in context
- Authors: Wright, Laurence
- Date: 2004
- Language: English
- Type: text , article
- Identifier: vital:7036 , http://hdl.handle.net/10962/d1007372 , http://hdl.handle.net/10520/EJC47870
- Description: preprint , It is rare for a writer to make a literary impact with only one novel. It is even more unusual when that work is written by a novice author in his early sixties. Yet such is the case of R.L. Peteni, whose novel, Hill of Fools, was published by David Philip in South Africa in 1976, and internationally in the same year by Heinemann in the African Writers Series. Four years later, in 1980, the book was translated by the author into Xhosa as Kwazidenge and published by the Lovedale Press. Twenty years after initial publication, in 1996, there came a television version of Kwazidenge broadcast by the SABC, starring Willie Thambo and Amanda Quwe, though the locale was translated – in the bizarre logic of television – to an urban environment on the Cape Flats. The transposition, though pragmatic in terms of television demographics, destroyed much of the point of Peteni’s work, for Hill of Fools is South Africa’s first regional novel in English by a black writer. It is also the first novel in English by a Xhosa-speaker.
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An XML-Based Approach to the Generation and Testing of mLAN Sound Installation Configurations
- Authors: Foss, Richard , Laubscher, Ron , Fujimori, J I
- Date: 2004
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/427267 , vital:72426 , https://www.aes.org/e-lib/browse.cfm?elib=12787
- Description: An application, called the mLAN Installation Designer, has been developed that enables the user to graphically design and validate an mLAN sound installation. This application is built upon a model of mLAN systems that is defined by an Extensible Markup Language (XML) Schema, ensuring cross platform portability and future scalability. The XML Schema provides sufficient flexibility to form the basis for a standard effort to describe the configuration of IEEE 1394 based sound installation environments. The output from the mLAN Installation Designer application file is an XML document, consistent with the defined schema, which allows a configuration tool to configure the mLAN devices for automatic operation during deployment of the system.
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Catalytic activity of iron and cobalt phthalocyanine complexes towards the oxidation of cyclohexene using tert-butylhydroperoxide and chloroperoxybenzoic acid
- Authors: Sehlotho, Nthapo , Nyokong, Tebello
- Date: 2004
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/290257 , vital:56729 , xlink:href="https://doi.org/10.1016/j.molcata.2003.08.014"
- Description: Cyclohexene oxidation using tert-butylhydroperoxide (TBHP) or chloroperoxybenzoic acid (CPBA) in the presence of iron(II) polychlorophthalocyanine (Cl16PcFe), iron(II) phthalocyanine (PcFe) and cobalt(II) phthalocyanine (PcCo), results in the formation of the following products: cyclohexene oxide, 2-cyclohexene-1-ol and 2-cyclohexene-1-one. Adipic acid was also formed after long reaction times. The selectivity for 2-cyclohexene-1-one is favoured when Cl16PcFe or PcCo catalysts are employed, while PcFe is selective towards the formation of 2-cyclohexene-1-ol. The Cl16PcFe catalyst is transformed into a μ-oxo dimer (Cl16PcFeIIIOIIIFePcCl16) during the oxidation process. The catalytic process using the unsubstituted PcCoII and PcFeII catalysts involved PcMIII species as an intermediate. The active form of the Cl16PcFe catalyst was stable to degradation in that it was still active even after 4 weeks of continued catalysis.
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Competition for attachment of aquaculture candidate probiotic and pathogenic bacteria on fish intestinal mucus:
- Authors: Vine, Niall G , Leukes, Winston D , Kaiser, Horst , Daya, Santylal , Baxter, Jeremy , Hecht, Thomas
- Date: 2004
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/142819 , vital:38120 , DOI: 10.1111/j.1365-2761.2004.00542.x
- Description: Probiotics for aquaculture are generally only selected by their ability to produce antimicrobial metabolites; however, attachment to intestinal mucus is important in order to remain within the gut of its host. Five candidate probiotics (AP1–AP5), isolated from the clownfish, Amphiprion percula (Lacepéde), were examined for their ability to attach to fish intestinal mucus and compete with two pathogens, Aeromonas hydrophila and Vibrio alginolyticus. Two different radioactive isotopes were used to quantify competition between pathogens and probionts. Attachment of the pathogens was enhanced by the presence of the candidate probiotics. However, the addition of the candidate probiotics after the pathogens resulted in reduced pathogen attachment.
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Decryption of Wire-level Network Protocols for Forensic Inspection
- Authors: Irwin, Barry V W
- Date: 2004
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/428339 , vital:72504 , https://www.researchgate.net/profile/Barry-Irwin/publication/327622612_Decryption_of_Wire-lev-el_Network_Protocols_for_Forensic_Inspection/links/5b9a1220299bf14ad4d6a3b1/Decryption-of-Wire-level-Network-Protocols-for-Forensic-Inspection.pdf
- Description: With the increased use of encrypted transport protocols, the problem of debugging and monitoring the contents of these protocols has in-creased in complexity. This work proposes the development of a unified means of access to the plaintext, through the use of privileged access to the encryption keys, based on the assumption that an administrator has legitimate access to one side of a communication, and is thereby able to gain access to the encryption tokens.
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Determination of 2′, 3′-Dideoxyinosine Using Iron (II) Phthalocyanine Modified Carbon Paste Electrode
- Authors: Ozoemena, Kenneth I , Stefan, Raluca-Ioana , Nyokong, Tebello
- Date: 2004
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/300298 , vital:57914 , xlink:href="https://doi.org/10.1081/AL-200031940"
- Description: An amperometric sensor, based on carbon paste impregnated with iron (II) phthalocyanine complex (FePc), has been constructed for the assay of anti‐HIV agent dideoxyinosine (didanosine, DDI). Using chronoamperometry (E = +1.04 V versus Ag/AgCl) technique, the amperometric sensor can be used reliably for dideoxyinosine assay at pH 7.4 phosphate buffer in the 1.5–9.5 nmol/L concentration range with a detection limit of 5.7 × 10−10 mol/L. The surface of the electrode can easily be regenerated by simple polishing, obtaining a fresh surface ready for use in a new assay. The new amperometric sensor proved to be highly reliable for the assay of dideoxyinosine purity in raw material as well as for the uniformity content test of Videx® tablets.
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Discourse domination?: the role of gender in seminar interaction
- Authors: De Klerk, Vivian A , Hunt, Sally
- Date: 2004
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/139160 , vital:37710 , https://www.ajol.info/index.php/salas/article/view/6501
- Description: This paper focuses on the effect of the gender of participants on the discourse patterns of university seminars, and compares the interaction patterns in two undergraduate seminars with those in two post-graduate seminars at Rhodes University. In the undergraduate seminars, two different groups of students at first year level in different disciplines were videotaped. The major difference was in terms of composition: in one seminar, there were equal numbers of male and female students, while in the other, female students dominated numerically (75%). In addition, five of the six formed a close-knit group of friends, which proved to be an important factor in the analysis. At the postgraduate level, the student participants were identical and met in the same venue and at the same time on two successive days to discuss the same topic (affirmative action in the workplace). The important difference between the two classes was the fact that the first seminar was led by a female tutor and the second seminar by a male tutor, both under 40 years of age and white, both members of staff in the department, and both known to the students. The discourse patterns in these two sets of seminars were analysed in order to investigate the ways in which the gender of tutors and students influenced the floor-winning and floor-holding conventions of participants.
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Distinct kimberlite pipe classes with contrasting eruption processes
- Authors: Skinner, E M W , Marsh, Julian S
- Date: 2004
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/150603 , vital:38988 , https://doi.org/10.1016/j.lithos.2004.03.044
- Description: Field and Scott Smith [Field, M., Scott Smith, B.H., 1999. Contrasting geology and near-surface emplacement of kimberlite pipes in southern Africa and Canada. Proc. 7th Int. Kimb. Conf. (Eds. Gurney et al.) 1, 214–237.] propose that kimberlite pipes can be grouped into three types or classes. Classical or Class 1 pipes are the only class with characteristic low temperature, diatreme-facies kimberlite in addition to hypabyssal- and crater-facies kimberlite. Class 2 and 3 pipes are characterized only by hypabyssal-and crater-facies kimberlite.
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Electrochemical and catalytic properties of chromium tetraaminophthalocyanine
- Authors: Obirai, Joe , Nyokong, Tebello
- Date: 2004
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/300310 , vital:57915 , xlink:href="https://doi.org/10.1016/j.jelechem.2004.06.026"
- Description: Chromium tetraaminophthalocyanine (CrIIITAPc) has been synthesized and its electrochemical and spectroelectrochemical properties reported. The first reduction and oxidation in this complex occur at the central metal, giving CrIITAPc and CrIVTAPc complexes, respectively, the latter having been observed for the first time. The CrIIITAPc species was polymerized onto glassy carbon (GCE) or indium tin oxide (ITO) electrodes and the polymer evolution confirmed by UV/Visible spectroscopy and by scanning electron microscopy. The polymers were employed for the catalytic oxidation of nitrite or nitric oxide, and the catalysis involved the CrIVTAPc−1 species.
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