The history of marine fish systematics in South Africa
- Authors: Gon, O (Ofer), 1949-
- Date: 2003
- Subjects: J.L.B. Smith Institute of Ichthyology Fishes -- Research -- South Africa -- History Fishes -- Catalogs and collections -- South Africa -- History Museums -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2599 , http://hdl.handle.net/10962/d1007800
- Description: South African marine fish collections and systematic research are relatively young, essentially a product of the 20th century. Their history in South Africa comprises three distinct periods: the emergence of fish collections (before 1895), the beginning of research (1895-1945) and modern research (1945-1999). From the outset of their arrival in South Africa in the mid-17th century, the European settlers of the Cape Colony supplemented their diet with fishes. Therefore it is not surprising that when natural history museums appeared in the 19th century fishes were among the first specimens they procured or received from the public. In these early days, fishes were acquired for display purposes and were curated together with other natural history specimens. There were no fish collections as such and, in many ways, the early history of South African fish collections closely followed the history of the institutions in which they were housed. Major political events in South Africa between 1850-1910 had little effect on the slow growth offish collections as the low influx of specimens from the public did not change. None of the museums did any active fish collecting and no fish research as such took place during these years. The second period in the growth of fish collections in South Africa was characterised by a general shift to collecting for research rather than display. It was also a period during which the need for aquatic research was recognized by and began to attract funding from the South African government, starting with the establishment of the Marine Biological Survey in Cape Town. However, with the exception of the Albany Museum's self-trained J.L.B. Smith, no trained marine fish systematists were working in museums either as curators or as researchers. In the first half of the 20"' century South Africa experienced the fast growth of the fishing industry, the development of academic and applied research in marine biology, and the thriving of sport fishing. These developments created a demand for well-trained professional ichthyologists. J.L.B. Smith was the first to fill this professional gap. The growth rate offish collections increased significantly through the interaction between museum scientists, such as Smith in Grahamstown and K.H. Barnard in Cape Town, with the fishing industry, government biologists and fisheries officers, and anglers. Barnard's review of the South African marine fish fauna was published in mid-I920s. The discovery of the first living coelacanth placed South African ichthyology and Smith on the international stage. The identification of this fish, made by a relatively inexperienced Smith, changed the way ichthyology has been viewed in South Africa. At the beginning of the third period, largely due to the establishment of the Council for Scientific and Industrial Research in 1945, science in South Africa underwent a process of reorganisation. As funding became more available museums were able to enlarge their research staff. Natural history museums hired qualified experts to conduct research and manage collections of specific groups of organisms. For the first time, trained ichthyologists started working in museums and initiated research projects that were the main contributors to the growth of fish collections around the country. Furthermore it was a period of consolidation offish collections resulting in two large marine fish collections, one at the South African Museum, Cape Town, and another at the J .L.B. Smith Institute of Ichthyology, Grahamstown. This period also witnessed the establishment of the latter as a research institute dedicated to the study of fishes and its rise to international prominence. The last 55 years at J.L.B. Smith Institute of Ichthyology can be divided into two distinct periods, 1945-1967 and 1968-1999, each consisting of similar elements of research work and objectives. These included the research and production of major reviews of the fish faunas of South Africa, the western Indian Ocean and the Southern Ocean, as well as research on the coelacanth. While in the former period the work was done by one scientist, J.L.B. Smith, the latter period has been characterised by collaborative projects including scientists from South Africa and abroad. As this history shows, the establishment of a viable, long-lasting collection is a lengthy process. For about 60 years the durability of fish collections depended on the enthusiasm and persistence of individual curators and scientists who were not ichthyologists. More often than not, enthusiasm disappeared when such individuals left their museums. This dependence existed until Rhodes University College established the Department of Ichthyology (1947) and the South African Museum created a post specifically for the curation of the fish collection (1957) and thus ensured continuity. The continuity of biosystematic research in South Africa has been a minor concern for the nation's systematists for decades. The threats to marine fish systematics have been of a financial, political and professional nature. The latter has been the most serious one because of the dearth of South Africans trained in marine fish systematics. After J.L.B. Smith's death in 1968 M.M. Smith had to work hard to convince the Council for Scientific and Industrial Research and Rhodes University that she could step into her late husband's shoes. Realizing that there was nobody to take over from her she initiated the first and only postgraduate programme in ichthyology in South Africa. The teaching started in the academic year of 1970171 at the J.L.B. Smith Institute of Ichthyology, but to date only one student has completed a thesis in marine fish systematics. Due to the government's transformation policy all the practising marine fish systematists in South Africa will be retiring in the course of the present decade. Consequently, if no aspiring, motivated students appear on the scene in the next couple of years marine fish systematics in this country will be in a deep crisis by the year 2010, possibly even earlier.
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- Date Issued: 2003
Structural and synthetic investigations of diterpenoid natural products from southern African marine invertebrates
- Authors: Gray, Christopher Anthony
- Date: 2003
- Subjects: Ethyl acetoacetate Diterpenes Limpets -- South Africa Natural products -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4349 , http://hdl.handle.net/10962/d1005014
- Description: This thesis is divided into two parts. The first part (Chapter Two) documents a bioassay guided investigation of the ethyl acetate extracts of four marine invertebrates from Mozambique (an Irciniid sponge, a Haliclona sp. sponge, an ascidian tentatively identified as Diplosoma sp., and the soft coral Cladiella kashmani). Eight known compounds [ilimaquinone (2.1), renierone (2.7), N-formyl-1,2-dihydrorenierone (2.8), 1,6-dimethyl-7-methoxy-5,8-dihydroisoquinoline-5,8-dione (2.9), mimosamycin (2.10) 7Z-allylidene-5-hydroxy-7,7a-dihydro-2H-cyclopenta[b]pyran-6-one (2.11), flaccidoxide (2.18) and 11S,12S-epoxycembra-1Z,3E,7E-trien-14S-ol (2.19)] and a new diterpene [13S,14R-diacetoxy-11S,12R-epoxycembra-1Z,3E,7E-triene (2.20)] were isolated and identified using standard spectroscopic techniques. Anomalies in the published spectral data of 2.1 and 2.8 were exposed and corrected, and the absolute stereochemistry of the cembrane diterpenes 2.18 and 2.20 established using the modified Mosher’s method. The comparative activities of the nine natural products against four cancer cell lines (A549, LOX, OVCAR3, SNB19) are reported. The second part of the thesis (Chapter Three – Chapter Six) is concerned with an ecological, structural and synthetic study of diterpenes from the endemic South African pulmonate limpet Trimusculus costatus. Two new labdane diterpenes [6b,7a-diacetoxylabda-8,13E-dien-15-ol (3.10) and 2a,6b,7a-triacetoxylabda-8,13E-dien-15-ol (3.11)] were isolated from T. costatus and evaluated for anti-feeding activity against the common predatory fish Pomadasys commersonnii. A strategy for the semi-synthesis of 3.10 from rhinocerotinoic acid (4.14), a diterpene reportedly present in the ubiquitous South African shrub Elytropappus rhinocerotis, was devised in order to allow further bioactivity tests to be performed and unequivocally assign the unknown absolute stereochemistry of the T. costatus metabolites. Attempts to isolate rhinocerotinoic acid from local specimens of Elytropappus rhinocerotis were unsuccessful, and as the repetition of a published synthesis of 4.14 from (-)-sclareol (4.15) gave rhinocerotinoic acid in unacceptably low yields with poor stereoselectivity, an improved synthesis of 4.14 is presented. Comprehensive studies using hispanone (5.1) as a model compound showed that 6,7-dioxygenated labda-8-enes could be prepared from compounds possessing a 7-oxo-labda-8-ene skeleton with some degree of stereocontrol. In the process, fourteen new hispanone analogues were prepared and most of these were tested for activity in a suite of ten agro-chemical assays. The novel compound 7b-hydroxy-9a-carbonitrile-15,16-epoxylabda-13(16),14-dien-6-one (5.34) exhibited significant activity against the crop fungus Phytophthora infestans and is currently being subjected to further agro-chemical tests. Unfortunately, the results from the oxygenation study performed on the model compound 5.1 could not be directly extrapolated to rhinocerotinoic acid. Attempts to prepare the naturally occurring 3.10 from 4.14 via an alternative route were unsuccessful but yielded an analogue of 3.10 in which the substituents at C-6 and C-7 are in a diequatorial rather than a diaxial configuration.
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- Date Issued: 2003
Morphometrics and reproduction of Terebrasabella heterouncinata (Polychaeta:Sabellidae), infesting abalone (Haliotis midae) from different culture environments
- Authors: Gray, Michael
- Date: 2003
- Subjects: Polychaeta , Sabellidae , Abalones -- Physiology , Abalones -- Nutrition , Abalone culture
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5384 , http://hdl.handle.net/10962/d1018231
- Description: In the late 1980's abalone culturalists noticed reduced growth rate and shell deformities in some abalone stocks. These problems were the result of infestations by a shell boring polychaete, Terebrasabella heterouncinata. Under intensive abalone culture conditions the level of infestation can reach epidemic proportions and there are often severe consequences for the host abalone. Heavy sabellid infestation levels have placed the economic viability of several South African farms under threat. This study formed part of an ongoing project that is aimed at investigating the basic biology of Terebrasabella heterouncinata. The majority of abalone farmers in South Africa feed their abalone either naturally occurring kelp (Ecklonia maxima) or the formulated abalone feed, Abfeed. Farmers have suggested that the use of Abfeed is associated with higher sabellid infestation levels and changing the abalone diet from Abfeed to kelp helps reduce sabellid infestation. Speculation has arisen indicating that older, slower growing abalone are more susceptible to sabellid infestation. The effect of host abalone diet history and their growth on sabellid settlement success, morphometries and reproduction was quantified. To better understand the plasticity of the expression of life history traits the variability of morphometric and reproductive characteristics was compared between different farm environments. And more...
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- Date Issued: 2003
An analysis of selected World Trade Organisation agreements to determine whether they discriminate unfairly against developing economices
- Authors: Grimett, Leticia Anthea
- Date: 2013-07-29
- Subjects: World Trade Organization Foreign trade regulation General Agreement on Tariffs and Trade (Organization) Free trade -- Developing countries Foreign trade regulation -- Developing countries Competition, Unfair -- Developing countries
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3718 , http://hdl.handle.net/10962/d1008368
- Description: The focus of this thesis is the question whether or not the WTO discriminates unfairly against developing economies. In the absence of a test of guidelines for detennining unfairness or fairness of WTO provisions or Agreements has been drawn up using welfare economic and constitutional law principles as a foundation. Unfairness is therefore determined by asking whether the provisions of each Agreement are rational, proportional, efficient and whether they prevent the abuse of power amongst states. In addition, the economic effects of the provisions of the selected Agreements have been analysed to determine whether the relevant provisions are welfare enhancing and conclusive to promoting growth and development within developing economies. The Agreements chosed for analysis are the Agreements on Trade-related Investment Measures (TRIMS), Trade-related Intellectual Property (TRIPS), Agriculture and Services (GATS). The dispute settlement and negotiating process, labour standards and the impact of decreasing most-favoured nation rates on developing economy competitiveness is also discussed. Application of the test has shown that the WTO provisions do not reflect the interests of all members. Even though most member states are developing economies, the3 Agreements constantly cater foe developed country concerns and interests. Where provision is made for developing country interests, it is the LDC's who are favoured, with nonnal developing economies being bound by the same provisions as the developed economies. A fonnal, as opposed to a substantive, defmition has been adopted by the WTO, with a result that the process of equality is placed above the outcomes. While concessions have been made to development, members have not gone for enough. A main reason for the imbalance can be attributed to the negotiating process, which is based upon concessionary bargaining and trade-off. Those states with greater economic power are therefore at an advantage as they have the leverage needed to influence the outcomes of negotiations and hence the provisions of the various Agreements. Even with the LDC's, the WTO has been found to discriminate unfairly against developing economies because it does not adequately address developing country concerns. , KMBT_363 , Adobe Acrobat 9.54 Paper Capture Plug-in
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A comparison of depressed and non-depressed mothers' speech to two-month old infants in a South African peri-urban settlement
- Authors: Gulle, Gillian Julie
- Date: 2003
- Subjects: Postpartum depression Postpartum depression -- South Africa Mother and infant Mother and infant -- South Africa Speech perception in infants
- Language: English
- Type: Thesis , Masters , MSocSc
- Identifier: vital:3172 , http://hdl.handle.net/10962/d1007801
- Description: Research shows that maternal depression has adverse effects on mother-infant attachment and subsequent infant development (Cogill, Caplan, Alexandra, Robson & Kumar, 1986). The mechanisms through which this comes about are unclear. Murray & Cooper (1997) suggest an impaired pattern of mother-infant communication is responsible. Within this, Murray proposes that maternal speech may be a key factor. This study constitutes a preliminary exploration into the mechanisms through which maternal depression effects mother-infant interaction in South Africa. 147 predominantly Xhosa-speaking mother-infant dyads that took part in a broader epidemiological study on post-partum depression in Khayelitsha (Cooper, Tomlinson, Swartz, Woolgar, Murray & Molteno, 1999) made up the subjects. Maternal depression was assessed according to the Structured Clinical Interview for DSMIV (SCID). Maternal speech recorded from standard, five-minute, face-to -face mother-infant interactions was translated and analysed according to a coding system developed by Murray (Murray, Kempton, Woolgar & Hooper, 1993). The speech of depressed mothers to their two month old infants was compared to the speech of non-depressed mothers on dimensions of focus, affect and agency, and the role of infant gender was assessed. Results revealed no significant group differences for depression. Maternal speech to male infants was found to hold significantly less ascription of agency than to female infants. Findings suggest that maternal speech may be too narrow a marker of maternal depression in this context and that broader indices are needed. It is recommended that future research control for measures of social adversity, factor in cultural and language particularities, and consider contextual aspects of mother-infant interaction / attachment processes, in investigating the mechanisms through which post-partum depression leads to negative infant outcome in the developing world.
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- Date Issued: 2003
Novel approaches to the monitoring of computer networks
- Authors: Halse, G A
- Date: 2003
- Subjects: Computer networks , Computer networks -- Management , Computer networks -- South Africa -- Grahamstown , Rhodes University -- Information Technology Division
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4645 , http://hdl.handle.net/10962/d1006601
- Description: Traditional network monitoring techniques suffer from a number of limitations. They are usually designed to solve the most general case, and as a result often fall short of expectation. This project sets out to provide the network administrator with a set of alternative tools to solve specific, but common, problems. It uses the network at Rhodes University as a case study and addresses a number of issues that arise on this network. Four problematic areas are identified within this network: the automatic determination of network topology and layout, the tracking of network growth, the determination of the physical and logical locations of hosts on the network, and the need for intelligent fault reporting systems. These areas are chosen because other network monitoring techniques have failed to adequately address these problems, and because they present problems that are common across a large number of networks. Each area is examined separately and a solution is sought for each of the problems identified. As a result, a set of tools is developed to solve these problems using a number of novel network monitoring techniques. These tools are designed to be as portable as possible so as not to limit their use to the case study network. Their use within Rhodes, as well as their applicability to other situations is discussed. In all cases, any limitations and shortfalls in the approaches that were employed are examined.
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- Date Issued: 2003
The geochemistry of ore fluids and control of gold mineralization in banded iron-formation at the Kalahari Goldridge deposit, Kraaipan greenstone belt, South Africa
- Authors: Hammond, Napoleon Quaye
- Date: 2003
- Subjects: Gold ores -- Geology -- South Africa -- North-West Greenstone belts -- South Africa -- North-West Ore deposits -- South Africa -- North-West Geochemistry -- South Africa -- North-West
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5048 , http://hdl.handle.net/10962/d1008370
- Description: The Kalahari Goldridge mine is located within the Archaean Kraaipan Greenstone Belt about 60 km SW of Mafikeng in the Northwestern Province, South Africa. Several gold deposits are located within approximately north - south-striking banded iron-formation (BIF). Current opencast mining operations are focused on the largest of these (D Zone). The orebody is stratabound and hosted primarily in the BIF, which consists of alternating chert and magnetite-chloritestilpnomelane-sulphide-carbonate bands ranging from mm to cm scale. The ore body varies in thickness from 15 to 45 m along a strike length of about 1.5 km. The BlF is sandwiched between a sericite-carbonate-chlorite schist at the immediate footwall and carbonaceous meta-pelites in the hanging-wall. Further west in the footwall, the schists are underlain by mafic meta-volcanic amphibolite. Overlying the hanging-wall carbonaceous metapeiites are schist units and meta-greywackes that become increasingly conglomeratic up the stratigraphy. Stilpnomelane-, chlorite- and minnesotaite-bearing assemblages in the BlFs indicate metamorphic temperatures of 300 - 450°C and pressures of less than 5 kbars. The BIF generally strikes approximately 3400 and dips from 60 to 75°E. Brittle-ductile deformation is evidenced by small-scale isoclinal folds, brecciation, extension fractures and boudinaging of cherty BIF units. Fold axial planes are sub-parallel to the foliation orientation with sub-vertical plunges parallel to prominent rodding and mineral lineation in the footwall. Gold mineralization at the Kalahari Goldridge deposit is associated with two generations of subhorizontal quartz-carbonate veins dips approximately 20 to 40°W. The first generation consists of ladder vein sets (Group lIA) preferentially developed in Fe-rich meso bands, whilst the second generation consists of large quartz-carbonate veins (Group lIB), which crosscut the entire ore body extending into the footwall and hanging-wall in places. Major structures that control the ore body are related to meso-scale isoclinal folds with fold axes subparallel to mineral elongation lineations, which plunge approximately 067°E. These linear structures form orthogonal orientation with the plane of the mineralized shallowdipping veins indicating stretching and development of fluid - focusing conduits. A second-order controlling feature corresponds to the intersection of the mineralized veins and foliation planes of host rock, plunging approximately 008°N and trending 341°. G0ld is closely associated with sulphides, mainly pyrite and pyrrhotite and to a lesser extent with bismuth tellurides, and carbonate gangue. The ore fluid responsible for the gold deposition is in the C-O-H system with increased CH₄ contents attributed to localized hydrolysis reaction between interbedded carbonaceous sediment and ore fluid. The fluid is characterized by significant C0₂ contents and low salinities below 7.0 wt % NaCl equivalent (averages of 3.5 and 3.0 wt % NaCl equivalent for the first and second episodes of the mineralization respectively) . Calculated values of f0₂. ranging from 10⁻²⁹·⁹⁸ to 10⁻³²·⁹⁶ bars, bracket the C0₂-CH₄ and pyrite-pyrrhotite-magnetite buffer boundaries and reveal the reducing nature of the ore fluid at deposition. Calculated total sulphur content in the ore fluid (mΣs), ranges from 0.011 to 0.018M and is consistent with the range (10⁻³·⁵ to 10⁻¹M) reported for subamphibolite facies ore fluids. The close association of sulphides with the Au and nature of the fluid also give credence that the Au was carried in solution by the Au(HS)₂ - complex. Extensive epigenetic replacement of magnetite and chlorite in BIF and other meta-pelitic sediments in the deposit by sulphides and carbonates, both on meso scopic and microscopic scales gives evidence of an interaction by a CO₂- and H₂S-bearing fluid with the Fe-rich host rocks in the deposit. This facilitated Au precipitation due to changes in the physico-chemical conditions of the ore fluid such as a decrease in the mΣs and pH leading to the destabilization of the reduced sulphur complexes. Local gradients in f0₂ may account for gold precipitation in places within carbonaceous sediments. The fineness of the gold grams (1000*Au/(Au + Ag) ranges from 823 to 921. This compares favourably with the fineness reported for some Archaean BIFhosced deposits (851 - 970). Mass balance transfer calculations indicate that major chemical changes associated with the hydrothermal alteration of BIF include enrichment of Au, Ag, Bi, Te, volatiles (S and CO₂), MgO, Ba, K and Rb but significant depletion of SiO₂ and minor losses of Fe₂O₃. In addition, anomalous enrichment of Sc (average, 1247%) suggests its possible use as an exploration tool in the ferruginous sediments in the Kraaipan greenstone terrane. Evidence from light stable isotopes and fluid inclusions suggests that the mineralized veins crystallized from a single homogeneous fluid source during the two episodes of mineralization under the similar physicochemical conditions. Deposition occurred at temperatures rangmg from 350 to 400°C and fluid pressures ranging from 0.7 to 2.0kbars. Stable isotope constraints indicate the following range for the hydrothermal fluid; θ¹⁸H₂O = 6.65 to 10.48%0, 8¹³CΣc = -6.0 to -8.0 %0 and 8³⁴SΣs = + 1.69 to + 4.0%0 . These data do not offer conclusive evidence for the source of fluid associated with the mineralization at the Kalahari Goldridge deposit as they overlap the range prescribed for fluid derived from devolatization of deep-seated volcano-sedimentary piles near the brittle-ductile transition in greenstone belts during prograde metamorphism, and magmatic hydrothermal fluids. , KMBT_363 , Adobe Acrobat 9.54 Paper Capture Plug-in
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- Date Issued: 2003
Geotectonic controls on primary diamond deposits : a review of exploration criteria
- Authors: Hannon, Camille
- Date: 2013-05-23
- Subjects: Diamonds , Geology, Structural , Diamond deposits , Kimberlite
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5047 , http://hdl.handle.net/10962/d1007810 , Diamonds , Geology, Structural , Diamond deposits , Kimberlite
- Description: The origin of diamonds, their preservation and transport to the surface have been important issues over the last decades after the acknowledgement that diamonds are xenocrysts in the host kimberlites and after the discovery of new transport media such as lamproites. Different types of diamonds -E-type diamonds, P-type diamonds- and different types of hosts - Eclogites, Peridotites- have been distinguished. Each type corresponds to particular formation criteria. Ecogitic Diamonds are mostly related to subduction processes, whereas more uncertainties remain regarding the formation of Peridotitic Diamonds. Komatiite extraction and subduction of graphite-bearing serpentinites have been proposed as the more likely processes involved in their formation. A typical mantle signature for diamonds implies a thick, cool, reduced lithosphere. The keel-shape model is the most popular. Archaean cratons are therefore the most promising exploration target and area selection will expect to follow the Clifford's Rule. However, the evidence of cratonic areas hidden under younger formations · through seismic profiles and the discovery of diamond structurally trapped outside their stability field, have increased the potential of diamondiferous areas. Preservation of diamonds inside the lithosphere requires that the mantleroot remains insulated against excessive reheating and tectonic reworking. Mantle-root friendly and mantle-root destructive structures are distinguished. Small-size cratons are usually the most promising exploration targets. Transport of diamonds to the surface is dependant on' the same criteria of preservation. Only kimberlites and lamproites have been recognized as efficient transport media. Their ascent to the surface is conditioned by a multitude of parameters, amongst them the nature of the magma, the speed of ascent, the presence of pre-existing structures in the crust and the availability of ground water in the near-surface environment. The origin of kimberlite magma probably lies near the transition zone. Mixtures of depleted asthenospheric · sources and metasomatically enriched and possibly subducted materials are likely to be at the origin of the different kimberlite magmas. Kimberlite magmatism correlates generally in time with global tectonic events, triggered by either plume activity or by subduction processes, depending of the tectonic school of thought. Kimberlite alignments have been interpreted as hotspot tracks, and kimberlite magmas as volatile-rich melts issued from the remaining plume tail. The plume head produces flood-basalts in an adjacent "thinspot" of the lithosphere, generally on the edges of the cratons. Kimberlite and lamproite ascent to the surface are unconditionally influenced by regional structures. Rift structures, ring structures, transform faults, suture zones and deep-seated faults have been mentioned as controlling or accompanying features of kimberlite magmatism. Nearsurface emplacement constraints are better understood and the ultimate shape of the intrusion(s) depends on the nature of the country rocks, the availability of ground water and the near-surface faulting pattern. The recent discovery of "fissure" kimberlites is one of the more important breakthroughs of the last decade. With a better understanding of the processes involved in diamond formation, preservation and of kimberlite emplacement, major diamond discoveries have recently increased on all the continents. Successful diamond exploration requires today an integration of all geophysical, petrologic, geochemical and structural information available. The particular study of the northwestern Australian lamproite and kimberlite fields, the Brazilian kimberlites, the easternNorth American kimberlite fields, the Lac de Gras kimberlite field, the South African rich kimberlite provinces, and the Yakutian kimberlite fields provide concrete examples of the geotectonic controls on primary diamond deposits. Area selection criteria based on the previous models and examples, are expected to yield to many more discoveries in the coming years. , KMBT_363 , Adobe Acrobat 9.54 Paper Capture Plug-in
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Biogeography and community structure of fishes in South African estuaries
- Authors: Harrison, Trevor D
- Date: 2003
- Subjects: Estuarine ecology -- South Africa Estuarine fishes -- South Africa Fish communities -- South Africa Biogeography -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5235 , http://hdl.handle.net/10962/d1005078
- Description: The biogeography and community structure of the fishes of South African estuaries was investigated. In all, 109 systems were examined representing two broad types: temporarily closed and permanently open estuaries. Multivariate analyses of the fish communities identified three biogeographic regions. A cool-temperate region extended along the west and southwest coasts; a warmtemperate zone stretched along the south, southeast and east coasts and a subtropical region occurred along the east coast. The boundaries of these biogeographic regions were also delineated. The general physico-chemical characteristics of the estuaries within the three biogeographic regions also reflected regional differences in climate, rainfall and ocean conditions. Estuarine temperatures followed the trend for marine coastal waters, decreasing from subtropical estuaries toward cool-temperate systems. The low rainfall and runoff in the warm-temperate region together with high evaporation rates and strong seawater input resulted in higher salinities in these estuaries. These factors also accounted for the predominantly clearer waters in warm-temperate estuaries. The estuaries in the three biogeographic regions were also shown to contain somewhat distinctive fish assemblages. Temperature and salinity appeared to be the two main factors affecting the distribution and abundance of fishes in South African estuaries. Subtropical systems were characterised by fishes mostly of tropical origin as well as certain south coast endemic species. Warm-temperate estuaries were dominated by endemic taxa with some tropical species also present. The fish fauna of cooltemperate estuaries mostly comprised south coast endemic species with cosmopolitan and temperate taxa also present. Certain functional components of the ichthyofauna also exhibited slight differences between regions. Freshwater fishes were a major component of closed subtropical estuaries while estuarine resident species were more abundant in warm-temperate estuaries. Overall, estuarine-dependent marine species dominated the fish fauna of the estuaries in all biogeographic regions, signifying that South African estuaries perform a vital nursery function for this group of fishes. Slight differences were also apparent in the trophic structure of the fishes; these were related to environmental differences between regions. Zooplanktivores and fishes that feed on aquatic macrophytes/invertebrates assumed a relatively higher importance in warm-temperate systems. Overall, detritivores dominated the estuarine fish fauna in all regions, indicating that detritus forms the main energy source in South African estuaries.
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- Date Issued: 2003
An integrated economic developmental appraisal of the South African mariculture industry
- Authors: Hepburn, Bruce
- Date: 2003
- Subjects: Mariculture -- South Africa -- Economic aspects
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:941 , http://hdl.handle.net/10962/d1002674 , Mariculture -- South Africa -- Economic aspects
- Description: Current coastal legislative and institutional reformulation has effectively established new principles for the promotion of sustainable, co-ordinated integrated coastal development to be achieved through facilitatory, co-operative management mechanisms. In accordance, collaborative expansion and diversification of mariculture has been identified as a strategic mechanism for realising sustainable coastal development. Present limited foundational understanding regarding the emergent commercial contingent’s economic-institutional structure has constrained the effectiveness of current centralised broad objective formulation based planning techniques. By drawing upon findings of the 2001 National Mariculture Baseline survey, key economic development and institutional components requiring dedicated attention for further realising industry’s inherent growth potential to supply domestic and growing global aquaculture markets are examined in an inductive explorative framework. Attention is also directed towards promoting realisation of collaborative mariculture development initiatives to redress dualistic development disparities in previously marginalised coastal localities. Finally, synthesis between traditional bureaucratic centralised co-ordinated planning and regionalised decentralised implementation orientated capacity building frameworks displaying a greater relevant stakeholder participatory ethos are examined.
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- Date Issued: 2003
The development of an instrument to measure intrapreneurship: entrepreneurship within the corporate setting
- Authors: Hill, Marguerite Elizabeth
- Date: 2003
- Subjects: Entrepreneurship , Psychology, Industrial , Organizational change
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2991 , http://hdl.handle.net/10962/d1002500 , Entrepreneurship , Psychology, Industrial , Organizational change
- Description: “Intrapreneurship is not a choice, it is the only survival attitude” (Pinchot, 2000, p.75). In 1985 Pinchot coined the term ‘intrapreneurship’, short for intra-corporate entrepreneurship, which describes the practice of entrepreneurship within organisations. Intrapreneurship is increasingly becoming a term used in the business world to describe organisations that are willing to pursue opportunities, initiate actions, and emphasise new, innovative products or services. Due to the dynamic nature of modern organisations, it is imperative that organisations and their managers remain receptive to new ideas, approaches and attitudes. It is therefore the belief that rapid and cost-effective innovation is the primary source of lasting competitive advantage in the twenty-first century, leaving organisations no alternative but to become intrapreneurial or cease to exist. This thesis focuses on this need and examines ways in which intrapreneurship can be measured in organisations in order to provide a benchmark for further organisational development. A questionnaire (known as the Intrapreneurial Intensity Index) was designed and distributed to a sample of 500 employees working in large South African organisations, which classified themselves as ‘forward-thinking’ and aimed for an intrapreneurial ‘type of thinking’. The results obtained from these questionnaires underwent item analysis, after which the questionnaire was redesigned in an electronic format. A pilot case study was then conducted in order to test the reliability of the instrument. Finally the questionnaire was redistributed to a sample of six organisations that are viewed as being ‘intrapreneurial’ and two that are regarded as being ‘non-intrapreneurial’. The data from this sample was used to test the validity of the Intrapreneurial Intensity Index and to demonstrate its application. This study resulted in an instrument that can be used to ascertain the intensity of intrapreneurship present in a large organisation. Specifically, this instrument can provide an overall view of the organisation’s intrapreneurial ability, as well as identify the specific areas in the organisation that require change or modification in order to become more intrapreneurial. This instrument provides a valuable means of identifying areas in need of organisational change, by determining an organisation’s intrapreneurial properties in the organisation’s core areas.
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- Date Issued: 2003
The importance of managing cultural change in the succession process within family businesses in the Gauteng area
- Authors: Hynd, Dale Vaughan
- Date: 2003
- Subjects: Family-owned business enterprises -- South Africa Family-owned business enterprises -- Succession Corporate culture -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3173 , http://hdl.handle.net/10962/d1007802
- Description: The aim of this research was to ascertain the implications and the impact that the succession process would have on the organisational culture of family businesses. In an attempt to answer this, the researcher asked three questions surrounding the succession process and its relationship with organisational culture. The questions related to the extent to which the family business was prepared for change in management; what changes occurred before, during, and immediately after the succession process, and what results these changes had on the organisational culture. Family businesses account for a large proportion of the national and global market activities, and so it is imperative that attention be paid to any problems they may experience. As it is, family businesses have difficulty in successions, with roughly one third of first generation family businesses surviving the succession process. It is the aim of this research to explore the contribution organisational culture has in the large failure rate of succession with family businesses. When successors enter into the organisation, they bring with them different perspectives on managerial issues suggesting that a change in leadership style will occur as a result of a succession. In answering the research questions, the researcher embarked on a two-phase research methodology utilising a quantitative and qualitative process. This triangulation process incorporates a self-administrated survey questionnaire, and six in-depth interviews. The survey questionnaire and interview schedules were structured using a combination of elements obtained from Harris's (1998) and Levinson's (1972). The survey data was analysed using various statistical methods, predominantly a Factor Analysis, where as Abstract iii the interviews were analysed using a theme retrieval process. The two processes were combined to yield the results. The findings of the research conclude that through the introduction of the successor in the change process, a new leadership style is introduced into the business. The new leader changes policies, practices and procedures, which are related to organisational climate and are the tangible aspects of organisational culture. Altering the climate essentially alters the culture, which may result in anxiety within the organisation and lead to tension. If these issues are not addressed, they may result in the demise of family businesses.
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- Date Issued: 2003
Binding and transcriptional activation by Uga3p, a zinc binuclear cluster protein of Saccharomyces cerevisiae redefining the UAS [subscript GABA] and the Uga3p binding site
- Authors: Idicula, Anu Mary
- Date: 2003
- Subjects: Saccharomyces cerevisiae GABA
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3933 , http://hdl.handle.net/10962/d1003992
- Description: Uga3p, a member of the zinc binuclear cluster transcription factor family, is required for [gamma]-aminobutyric acid-dependent transcription of the UGA genes in Saccharomyces cerevisiae. Crystallographic data of some of the protein-DNA complexes of this family reveal that members of this family bind to CGG triplets. A conserved 19-nucleotide activation element in certain UGA gene promoter regions contains a CCG-N4-CGG everted repeat, proposed to be the binding site of Uga3p, UAS[subscript GABA]. The spacer region (N4) between the CGG triplets has been suggested to be the specificity determinant for binding to UAS[subscript GABA]. The data available from the Saccharomyces genome database indicates that there are multiple repeats of -CCG-N4-CGG- regions within the genome. These transcription factors are involved in the activation of specific pathways and the question arises as to how their specificity of binding is determined. The aim of this study was to understand the binding characteristics of Uga3p to UAS[subscript GABA] and to determine the affinity and specificity of this interaction. In this study, full-length (tagged and untagged) and truncated (1-124 a.a.) Uga3p was produced in a heterologous expression system (E. coli). The interaction of Uga3p with UAS[subscript GABA] in Saccharomyces cerevisiae was characterized in terms of binding in vitro and the transcriptional activation of lacZ reporter genes in vivo. The Uga3p was capable of binding to these sites in vitro independent of exogenous GABA. Electrophoretic mobility shift assays (EMSA) of the full-length Uga3p with the wild type UAS[subscript GABA] sequences produced two distinct mobility complexes. The complexes formed in the EMSA of the full-length Uga3p were those specific to the interaction of the Uga3p to UAS[subscript GABA]. The truncated Uga3p(1-124 a.a.), which has the DNA-binding zinc cluster domain, the linker region and the putative coiled-coil domain was not functionally equivalent to the full-length protein with respect to binding in vitro because the EMSAs of the UAS[subscript GABA] with the truncated Uga3p produced indistinct complexes. EMSAs using mutant UAS[subscript GABA] sequences and heterologously-produced full-length Uga3p, demonstrated that UAS[subscript GABA] consists of two, independent Uga3p-binding sites. This work presents evidence that the two Uga3p molecules bound to UAS[subscript GABA] most likely interact with each other. Unlike other zinc cluster binding sites the Uga3p-binding site is an asymmetric site of 5’-SGCGGNWWT-3’ (S= G or C, W = A or T and N = no nucleotide or G or C). UAS[subscript GABA] is a palindrome containing the two asymmetric Uga3p-binding sites. The two-site consensus sequence required for the binding of Uga3p to the UAS[subscript GABA] is present upstream of UGA1 (region -387 to -370) and UGA4 (region -403 to -387). Furthermore, a single Uga3p-binding site was identified in the 5’ untranslated regions of UGA2 (region -219 to -211). GABA-dependent transcriptional activation by UAS[subscript GABA] in vivo could be directly correlated to a high affinity, specific interaction of two Uga3p molecules to this UAS. Binding with high affinity required the conserved sequences flanking the everted repeat. This study provided evidence that the binding pattern of Uga3p is novel compared to other zinc cluster motifs investigated, as the sequences flanking the everted repeat are important regions for recognition by Uga3p. The studies with the truncated Uga3p (1 –124 a.a.), also suggested that the regions C-terminal to the DNA-binding motif and putative coiled-coil area of this protein are important for Uga3p-specific interactions with UAS[subscript GABA]. Investigation of regions C-terminal to the zinc cluster, linker and putative coiledcoil revealed an eight-motif regulatory region similar to that in other zinc cluster proteins. This indicated that the regions C-terminal to these domains are important for the regulation and activity of these proteins. A putative seven repeat WD40-like motif was identified within this region. This putative domain has been speculated to be important for protein-protein interactions. Phosphorylation and dephosphorylation in other proteins of this class have been indicated to be important for the regulation of the activity of these proteins. The bioinformatic analysis of Uga3p revealed two possible cAMP/cGMP-dependent protein kinase phosphorylation sites, four putative protein kinase C phosphorylation motifs and four putative casein kinase II phosphorylation motifs. This study has contributed to the understanding of the nature of interactions between Uga3p and its specific UAS [subscript GABA] and how the regions flanking the everted repeat determine its specificity. The comparison of the nature of the binding of truncated and full-length Uga3p in vitro provided evidence for the role played by the full-length protein in determining this specific interaction. This evidence suggested that the in vitro binding evidence for other proteins of this family, using truncated peptides that carry the DNA-binding domain, might not reflect the true nature of interactions between the proteins of this class and their specific UASs in vivo.
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- Date Issued: 2003
The impact of US Peace Corps volunteers on the management and leadership of a school in Namibia: a case study
- Authors: Ipangelwa, Anna
- Date: 2003
- Subjects: Peace Corps (U.S.) Volunteer workers in Education -- Namibia Education -- Namibia Education and state -- Namibia Educational change -- Namibia School management and organization -- Namibia Educational leadership -- Namibia
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1561 , http://hdl.handle.net/10962/d1003443
- Description: Peace Corps Volunteer teachers have played a significant role in Namibia’s attempts to restructure education in line with its policy of education for all. While we have learned a great deal in recent years about how Peace Corps Volunteer Teachers have achieved their stated goals and objectives of teaching students and training serving teachers, we still know relatively little about the role they may have played in school management. The purpose of this study is to examine the impact of Peace Corps volunteers work on the management and leadership of the schools they serve. The study focuses on the work of two volunteers based in a combined school in the Ondangwa West educational region of Namibia. The study adopts a qualitative approach and seeks to establish whether there has been an impact by Peace Corps volunteer’s work on the management and leadership of this school by focusing on (a) activities performed by Peace Corps volunteers; (b) the experiences of both management and staff in working with Peace Corps volunteers; (c) whether the presence of Peace Corps volunteers that served at the school influence the management and leadership of the school; (d) how the duties and activities performed by these volunteers were perceived by the students, teachers and community. The interview questions that were used to collect data from seven respondents were based on the literature from Peace Corps and the Ministry of Basic Education, Culture and Sport as well as education management and leadership literature. The findings indicate that volunteers that served at this school performed management and leadership related activities with the students, teachers and community and that these activities are having an effect on the management and leadership of the school.
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- Date Issued: 2003
Studies of the environmental and endocrine control of reproduction in the four striped field mouse, Rhabdomys pumilio
- Authors: Jackson, Claire
- Date: 2003
- Subjects: Microtus Microtus -- South Africa -- Reproduction Mice -- Reproduction
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5777 , http://hdl.handle.net/10962/d1005465
- Description: Previous studies of the control of reproduction in Rhabdomys pumilio have shown that day length alone does not inhibit spermatogenesis, that a reduction in food availability and ambient temperature results in an inhibition of gametogenesis, that females are more susceptible to inhibition than are males, and that mice that are able to maintain a body fat store in the face of an energetic challenge, are less likely to show reproductive inhibition than those that lose their fat store. In the present study, field and laboratory experiments were conducted to examine the effects of winter food supplementation on reproduction and population dynamics, and the effects of exogenous GnRH, leptin and mercaptoacetate (MA) on reproductive activity of Rhabdomys pumilio exposed to an energetic challenge. In the field food supplementation experiments in Thomas Baines Nature Reserve (2000, 2001), there was no winter inhibition of reproduction and provision of supplementary food had little effect. While at Mountain Zebra National Park (2002) winter was harsher, females became reproductively inactive, spermatogenesis continued and the provision of extra food resulted in higher rates of individual growth and larger reproductive organs. Treatment of mice that had been exposed to a prolonged energetic challenge, with exogenous GnRH (1µg/mouse/treatment) resulted in an increase in the masses of the testes and epididymides, and in the activity of the reproductive organs. Treatment with exogenous leptin (40µg/mouse/treatment), concurrently with an energetic challenge, countered the negative effects of the energetic challenge, and treated males had larger reproductive organs. MA (600µmol/kg body mass), given concurrently with an energetic challenge, did not inhibit fat metabolism, although the high-fat diet countered the effects of the energetic challenge. Results suggest that the first response of male Rhabdomys pumilio to an energetic challenge is a reduction in the size of the reproductive organs, without an inhibition of spermatogenesis. It is likely that this effect is mediated via white fat and leptin, and leptin’s influence on the hypothalamic-pituitary-gonad axis. Results of the study support the suggestion that females are more sensitive to reproductive inhibition than males and that reproduction in Rhabdomys pumilio is truly opportunistic.
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- Date Issued: 2003
An investigation into whether a leadership and management development project changed the perceptions of the educators in a black, disadvantaged school
- Authors: Jaftha, A P
- Date: 2003
- Subjects: University of Port Elizabeth -- Institute for Development Planning and Research Delta Foundation -- Centres of Learning School management and organization -- South Africa Educational leadership -- South Africa Educational change -- South Africa
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1620 , http://hdl.handle.net/10962/d1003502
- Description: This study investigates whether a leadership and management development programme changed the management perceptions of the teachers of one of the schools that participated in the programme. The programme seeks to change the organisational culture of schools and develop effective management. The development philosophy of the programme is informed by literature on school effectiveness, organisation development, whole school development and systemic change. My research is conducted in the interpretive paradigm. Interpretive researchers view reality a construct of the human mind, and therefore the way people perceive the world is not necessarily the same since there can be different understandings of what is real. I employ convenience sampling to select the school and purposive sampling to identify my research participants. Whilst overall impression that the data conveys is that much of the programme does not seem to have had a lasting effect on the culture of the school, it nonetheless made an impression on the teachers’ perceptions of management. There clearly seems to be a greater appreciation of participative management processes. The reintroduction of proper prior planning played a decisive role in re-establishing sound work ethics at the school and contributes to a more structured approach to events at the school. Some sort of organisational learning has also been introduced at the school. The realisation on the part of the staff that they now have their destiny in their own hands is an especially critical development. And whilst the vision is not a compelling force in the organisation, it has nevertheless produced some strategic focus at the school. The insights and skills they acquired concerning resource management will also stand them in good stead.
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- Date Issued: 2003
An investigation of the relative importance of the media in influencing the voting behaviour of Evelyn Hone College students in Lusaka during the December, 2001 presidential elections in Zambia
- Authors: Jere, Caesar
- Date: 2003
- Subjects: Voting -- Zambia Mass media -- Political aspects -- Zambia Presidents -- Zambia -- Election -- 2001
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3516 , http://hdl.handle.net/10962/d1007803
- Description: This study explores the relative importance of the media in influencing the electoral choices of a small group of Zambians, namely Evelyn Hone College students in Lusaka who participated in the December 2001 elections in Zambia. The study investigates the interplay of mediation between the lived cultural experiences of the sample of students and the impact of media messages. Students at Evelyn Hone College come from different ethnic groupings, social classes, religions and regions. They are exposed to both the state and the privately owned media, which represent a range of political viewpoints. The outcome of the December 2001 elections in Zambia gave the impression that people in urban areas in Zambia were less likely to vote on ethnic lines because they had easy access to different media, ranging from print to electronic, which provided them with diverse information about the political scene, and probably shaped their electoral choices. Conversely, their counterparts in the rural areas appeared to vote along ethnic lines, seemingly because of lack of exposure to the media. It was also assumed that most people in rural areas were not as modernized as their urban counterparts who were more exposed to enlightened sources of information such as professional groups and other elite social institutions which helped them to shape their political opinions than most rural people. The study attempts to establish to what extent the media impacted on the selected sample of urban students in the choice of their presidential candidates in the December 2001 elections in Zambia. The study further investigates to what extent other factors such as ethnic inclinations and other social predispositions influenced them in their choice of the candidates. The interviewees for this study were randomly drawn from a population of Evelyn Hone College students that voted in the December 2001 presidential elections in Zambia. The sample consisted of 30 randomly selected students who were purposely stratified in three focus groups of ten each. Each stratum represented the approximate ethnic equivalence of one of the presidential candidates who contested the December 2001 elections.
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- Date Issued: 2003
Intercohort cannibalism and parturition-associated behaviour of captive-bred swordtail, Xiphophorus helleri (Pisces: Poeciliidae)
- Authors: Jones, Clifford Louis Wilshire
- Date: 2003
- Subjects: Poeciliidae -- Behavior Xiphophorus helleri Fish culture
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5351 , http://hdl.handle.net/10962/d1007812
- Description: Adult fish that belong to the family Poeciliidae cannibalise juveniles, both in the wild and under captive conditions, but this behaviour has only been partly investigated in the Poeciliidae in some of the commercially valuable species. The objective of the research is to develop an understanding of intercohort cannibalism and parturition-associated behaviour in captive-bred swordtail (Xiphophorus helleri), with applications to industry and future research of other poeciliids. Experiments investigating the effect of adult stocking density and sex ratio on the production of juveniles were used to determine if cannibalism occurs under culture conditions. The average rate of intercohort cannibalism ranged from (5.5 to 53.9%), and was positively density dependent and independent of sex ratio, indicating that males and females were probably equally cannibalistic. The highest number of juveniles (1725.7±141.4) produced per tank over 70 days was obtained from two males and eight females. To develop a better understanding of adult and juvenile behaviour during parturition, fish were observed under controlled laboratory conditions using video and behaviours such as attack (burst of speed by an adult in the direction of a juvenile), escape (avoidance of cannibalism after attack) and cannibalism (predation of a live juvenile by an adult), for example, were identified. Under laboratory conditions most young escaped in downward direction after attack (49%) and most utilised the refuge made that was made available. Furthermore, most attacks (62-65%) and cannibalism (57-84%) occurred at the bottom. Since the presence of refuge significantly increased the rate of juvenile survival under culture conditions, it was hypothesised that the rate of cannibalism could be reduced under farming conditions if juveniles were protected when they escaped downwards. This hypothesis was accepted as it was found that refuge at the bottom of the water column or the inclusion of a false-bottom reduced the rate of cannibalism by 49% and 72%, respectively. Similarly, the hypothesise that the rate of cannibalism could be reduced if juveniles where given protection when escaping sideways (32% of juveniles escaped sideways in the laboratory) was also accepted when tested under farm-scale conditions because a false-side reduced the rate of cannibalism by an average of 45%. Since males and females were equally responsible for cannibalising juveniles in the laboratory, it was hypothesised that the rate of cannibalism would decrease proportionately with the removal of males (Le. 20% of the cannibals) from the population; the removal of males under farming conditions resulted in a 19.5% reduction in the rate of cannibalism. Since older juveniles were better able to escape cannibalism than neonates and since adults habituate to stimuli that previously resulted in attack behaviour, it was hypothesised that the rate of cannibalism would remain unaffected by the length of time that juveniles were exposed to adults in the breeding tanks. This hypothesis was also accepted when tested under farm conditions. However, some hypotheses based on laboratory observations were not accepted. For example, a constant low light intensity did not appear to decrease the rate of cannibalism under farm conditions; also, the occurrence of dead and deformed juveniles went unnoticed in the laboratory, and under farm conditions, where adults did not have access to the bottom of the tank, 10% of the harvest consisted of dead and deformed juveniles. It is concluded that technologies, such as bottom-refuge or a false-side, that increase the size of the liveharvest and allow for the removal of potentially less viable offspring are recommended for the commercial production of poeciliids. The overall similarity of X. helleri behaviour between the laboratory experiments and the farm-scale trials suggests that the post-partum behaviour of X. helleri remains consistent under these different conditions; thus, behaviour under one set of conditions may be used to predict behaviour under other conditions. The application and significance of extrapolations to industry and future research of X. helleri and possibly other poeciliids were discussed and the most applicable laboratory observations with the highest extrapolation capacity were proposed. Furthermore, techniques were developed to aid industry and future researchers in making predictions relating to behaviour of X. helleri under different conditions based on laboratory observations. The results were used to develop a model indicating that selection pressures against cannibalism are not likely to exist at the rate of cannibalism observed here since the potential genetic gain through kin survival and inclusive fitness was shown to be greater than any potential genetiC loss experienced by a victim of cannibalism. The model was successfully tested under a range of social conditions. Other possible explanations for cannibalism in poeciliids, such as parental manipulation, nutritional advantages, opportunistic predation and the recovery of energy are discussed. It is suggested that the most likely proximate cause of cannibalism under captive conditions is opportunistic predation. The theory that cannibalism ensures that only viable genes of the victim are expressed, through inclusive fitness, is a possible ultimate cause of cannibalism, which may have been inherited from feral ancestors of captive-bred X. helleri.
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- Date Issued: 2003
A critical investigation of managing the standards development process for the life insurance industry in Namibia
- Authors: Kaimu, Himeesora Irene
- Date: 2003
- Subjects: Life insurance -- Management -- Namibia Insurance -- Namibia
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1481 , http://hdl.handle.net/10962/d1003362
- Description: The development of standards for education and training is regarded as a very important activity by many countries. Any country that sets standards for education and training is trying to define its training system and avoid duplication of training by providers who do not see eye to eye. National standards are public documents accessible to anyone interested in education and training. Namibia introduced standards setting as a core activity of administering the National Qualifications Framework in 1996 after the passing of the Namibia Qualifications Act by parliament. This research attempts to gain an understanding of how the process of developing standards for the Life Assurance Sector in Namibia was managed by focusing on the experiences of three persons who took part in the process of developing the said standards. The case study approach enabled me to gain considerable insight into management issues that may have influenced the process of developing these specific standards. The findings illuminate the management and leadership issues which characterised the process for the LA Industry. Several management issues emerge as key elements in the process. These include: A strong emphasis on transformational leadership through clear vision crafting; empowerment through emancipatory thinking; OD features such as problem solving and effective communication; the importance of organisational structure; the concept of a learning organisation and benchmarking as well as collegiality. This research explores the relationship between management thinking generally, and the management of the standards development process in particular.
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- Date Issued: 2003
Putting participatory communication into practice through community radio: a case study of how policies on programming and production are formulated and implemented at Radio Graaff-Reinet
- Authors: Kanyegirire, Andrew Steve Tumuhirwe
- Date: 2003
- Subjects: Radio broadcasting -- South Africa -- Graaff-Reinet , Radio in community development , Radio stations -- South Africa -- Graaff-Reinet -- Management
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3442 , http://hdl.handle.net/10962/d1002896 , Radio broadcasting -- South Africa -- Graaff-Reinet , Radio in community development , Radio stations -- South Africa -- Graaff-Reinet -- Management
- Description: In the South African (SA) model of community radio, listeners are expected to be in charge of the management and programming operations of stations. This study tests the SA model against the actual conditions at an existing station. For this purpose, the study focuses on Radio Graaff-Reinet, a community radio station in the Eastern Cape. Emphasis is on examining the extent to which members of the station’s target community are involved in its operations. The study first assesses the nature of this involvement, keeping in mind the principles of, ‘community ownership’ and ‘participatory programming’ on which the SA model of community radio is based. It is argued that the station does provide a valuable ‘public sphere’ for its listeners. The potential of this sphere remains limited, however, due to the impact of ongoing power struggles around the ownership of the station. The lack of proper systems for managing these struggles has contributed to the fact that the station continues to be in a constant state of flux, with a high turnover of staff and regular changes in its policies and strategies. The study argues that, until such systems are put in place, the principles of community ownership will not be fully realizable. Areas in which the struggle over ownership plays itself out can be identified in the relationship between the station’s Board of Directors and its managing staff, between one particular station manager and her staff and between the station and its target community. These struggles often take place in context of a debate about the financial sustainability of the station versus its developmental aims. It is argued that this opposition needs to be questioned since, until the station is financially stable, it will remain vulnerable to interference by powerful individuals and groups in its attempts to establish such developmental aims. The study then goes on to identify key weaknesses in the station’s approach to community ownership and participation. In particular, it is pointed out that various stakeholders in the station have contradictory understandings of what is meant by ‘community’, using the term to include or exclude sections of the Graaff-Reinet society in very different ways. There are also very different understandings at play about the concept of community radio itself. These contradictions have an impact on the station’s ability to implement participatory programming. This situation is exacerbated by the fact that the station does not have a consistent forum in which shared decision-making can take place. Consequently, the station also remains unable to draw effectively on its own volunteer staff and on its community as resources for programming content. Finally, the study explores the broader significance of the weaknesses that exist in the case of Graaff-Reinet, arguing that these are problems that repeat themselves throughout the South African community radio sector. Possible strategies for addressing these problems are suggested, including approaches to monitoring and research, training, organizational development and advocacy.
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- Date Issued: 2003