Showing items 22921 - 22940 of 27194

Your selections:

Studies on the biology of the economic marine red alga Gelidium pristoides (Turner) Kuetzing (Gelidiales : Rhodophyta)

  • Authors: Carter, Alan Robert
  • Date: 1987
  • Subjects: Red algae Marine algae
  • Language: English
  • Type: Thesis , Doctoral , PhD
  • Identifier: vital:4240 , http://hdl.handle.net/10962/d1004774
  • Description: Various aspects of the biology of the intertidal agarophyte, Gelidium pristoides, were investigated, with the aim of providing information that would assist in formulating a management policy for this economic seaweed resource. G.pristoides occurs as tufts comprising as many as 40 individual plants, representing all three conspicuous life history stages, that are linked by the intertwining of their basal creeping axes. Individual plants consist of a system of branched creeping axes, which is largely responsible for colonizing surrounding substrata, from which one or more erect flattened fronds arise. These erect fronds may reach a height of 15 cm, and are irregularly bipinnately branched. Internal vegetative anatomy is generally typical of the genus. Morphological variation in mature plants is limited to increased plant height and branch density during the summer season. A dorso-ventrally flattened creeping habit was seen during early recruitment on flat rock surfaces and limpet shells within grazer exclusion plots, which developed into typical erect plants. Although there is a close taxonomic affinity between G.pristoides and the low-growing Gelidium turf, which occurs on wave-cut platforms in the eastern Cape (both produce bispores), the turf appears to represent a genetically divergent ecotype of the typical G.pristoides habit. In the light of present observations, it is suggested that the recent inclusion of G.pristoides in the new Onikusa genus should be questioned. Reproduction in G.pristoides is typical of the genus, except for the production of bispores, instead of tetraspores, in the sporophyte generation. The smaller nuclei in the binucleate bispores, in comparison to carpospores, suggested they are the product of normal meiosis (meiospores). This was confi rmed by chromosome counts of germl i ngs deri ved from bispores (n = 13-17) and carpospores (2n = 28-33). Throughout the geographical range of the seaweed, the bisporophyte generation is dominant over the combined male and female gametophyte generati on by a ratio of about 3 : 1. This imbalance may be due to bispores. G.pristoides a greater germination success of carpospores over plants are fertile throughout the year, while at Port Alfred there is no apparent seasonality in spore release. Growth of carpospore and bispore germlings is similar under various temperature treatments in culture. Optimum temperatures for growth were from 15-23°C, which corresponds with the sea temperatures experienced within the geographical range of the species . At Port Alfred, growth (linear frond elongation) and standing crop levels were maximal during summer . Ory weight levels were significantly inversely related to both growth and ash levels. Agar contents (% of dry weight) were generally greater in summer (48% ) than in winter (30%), and were inversely correlated with thallus nitrogen levels. Agar contents of distal plant halves were higher (8-15%) than in proximal halves. Regrowth of G.pristoides to original biomass or standing crop levels after harvesting, is similar for plucking and shearing at different times of the year. Regrowth is more rapid after spring and summer harvests (2-3 months) than after winter harvests (4-5 months). During the summer season, harvesting at monthly intervals showed significantly greater total yields, and production rates (e.g . 3.13 g. dry wt. / m2 / day for plucking) than under 3-monthly intervals (1.42 g. dry wt. / m2 / day for plucking). In contrast, average yields per harvest were Significantly greater when recovery period was longer (e.g. 3 months). Quadrats that were completely denuded failed to recover after a year, while regrowth was also retarded with increased elevation on the shore. Agar contents did not differ Significantly between plucked (38%) and sheared (42%) plant material. G.pristoides is distributed from about 0 . 2-0.75 m above MLWS, with a reduction in stature and frequency corresponding to increased elevation on the shore. Frond elongation rates, germling survival and recruitment within grazer-exclusion plots, is retarded with increased elevation level. Plants transplanted above the normal vertical range of the seaweed became severely bleached and died, while plants transplanted below the normal range of the seaweed (sub littoral fringe) senesced due to overgrowth by the epiphytic encrusting coralline, Polyporolithon patena (Hook . et Harv . ) Mason . G.pristoides recrui t ment in the sublittoral fri nge was enhanced with the exclusion of grazers . However, successful recruits were displaced due to smothering by articulated corallines (e.g. Corallina sp. and Jania sp. ) . G.pristoides is largely restricted to cracks and crevices in the rock, and also occurs on a large proportion of the available shells of the limpet Patella oculus Born., and to a lesser extent, shells of the barnacle Tetraclita serrata. G.pristoides recruitment was significantly enhanced by the exclusion of grazers (using toxic antifouling paint barriers). G.pristoides recruitment within the exclusion plots was significantly greater on artificially attached limpet shells (almost 100% cover) than on rock surfaces (20-30% cover), which occurred largely within cracks and crevies in the rocky substratum. ly attached to limpet G.pristoides plants are significantly more strongand barnacle shells than to rock and epilithic encrusting corallines (Lithothamnion sp.). Removal of G.pristoides from limpet shells revealed pits of a uniform size in the surface of the shells, into which the rhizoidal attachment organs of the seaweed penetrate. It is concluded that the horizontal distribution of G.pristoides is largely controlled by grazers (and "escapes" from grazing) and resistance to dislodgement by wave action. Based on present results, and considering some of the socio-economic factors associated with the Gelidium industry in South Africa, suggestions are made concerning the management and long-term maintenance of G.pristoides resources in the eastern Cape.
  • Full Text:
  • Date Issued: 1987

Studies on the biology of the economic marine red alga Gelidium pristoides (Turner) Kuetzing (Gelidiales : Rhodophyta)

  • Authors: Carter, Alan Robert
  • Date: 1987
  • Subjects: Red algae Marine algae
  • Language: English
  • Type: Thesis , Doctoral , PhD
  • Identifier: vital:4239 , http://hdl.handle.net/10962/d1004774
  • Description: Various aspects of the biology of the intertidal agarophyte, Gelidium pristoides, were investigated, with the aim of providing information that would assist in formulating a management policy for this economic seaweed resource. G.pristoides occurs as tufts comprising as many as 40 individual plants, representing all three conspicuous life history stages, that are linked by the intertwining of their basal creeping axes. Individual plants consist of a system of branched creeping axes, which is largely responsible for colonizing surrounding substrata, from which one or more erect flattened fronds arise. These erect fronds may reach a height of 15 cm, and are irregularly bipinnately branched. Internal vegetative anatomy is generally typical of the genus. Morphological variation in mature plants is limited to increased plant height and branch density during the summer season. A dorso-ventrally flattened creeping habit was seen during early recruitment on flat rock surfaces and limpet shells within grazer exclusion plots, which developed into typical erect plants. Although there is a close taxonomic affinity between G.pristoides and the low-growing Gelidium turf, which occurs on wave-cut platforms in the eastern Cape (both produce bispores), the turf appears to represent a genetically divergent ecotype of the typical G.pristoides habit. In the light of present observations, it is suggested that the recent inclusion of G.pristoides in the new Onikusa genus should be questioned. Reproduction in G.pristoides is typical of the genus, except for the production of bispores, instead of tetraspores, in the sporophyte generation. The smaller nuclei in the binucleate bispores, in comparison to carpospores, suggested they are the product of normal meiosis (meiospores). This was confi rmed by chromosome counts of germl i ngs deri ved from bispores (n = 13-17) and carpospores (2n = 28-33). Throughout the geographical range of the seaweed, the bisporophyte generation is dominant over the combined male and female gametophyte generati on by a ratio of about 3 : 1. This imbalance may be due to bispores. G.pristoides a greater germination success of carpospores over plants are fertile throughout the year, while at Port Alfred there is no apparent seasonality in spore release. Growth of carpospore and bispore germlings is similar under various temperature treatments in culture. Optimum temperatures for growth were from 15-23°C, which corresponds with the sea temperatures experienced within the geographical range of the species . At Port Alfred, growth (linear frond elongation) and standing crop levels were maximal during summer . Ory weight levels were significantly inversely related to both growth and ash levels. Agar contents (% of dry weight) were generally greater in summer (48% ) than in winter (30%), and were inversely correlated with thallus nitrogen levels. Agar contents of distal plant halves were higher (8-15%) than in proximal halves. Regrowth of G.pristoides to original biomass or standing crop levels after harvesting, is similar for plucking and shearing at different times of the year. Regrowth is more rapid after spring and summer harvests (2-3 months) than after winter harvests (4-5 months). During the summer season, harvesting at monthly intervals showed significantly greater total yields, and production rates (e.g . 3.13 g. dry wt. / m2 / day for plucking) than under 3-monthly intervals (1.42 g. dry wt. / m2 / day for plucking). In contrast, average yields per harvest were Significantly greater when recovery period was longer (e.g. 3 months). Quadrats that were completely denuded failed to recover after a year, while regrowth was also retarded with increased elevation on the shore. Agar contents did not differ Significantly between plucked (38%) and sheared (42%) plant material. G.pristoides is distributed from about 0 . 2-0.75 m above MLWS, with a reduction in stature and frequency corresponding to increased elevation on the shore. Frond elongation rates, germling survival and recruitment within grazer-exclusion plots, is retarded with increased elevation level. Plants transplanted above the normal vertical range of the seaweed became severely bleached and died, while plants transplanted below the normal range of the seaweed (sub littoral fringe) senesced due to overgrowth by the epiphytic encrusting coralline, Polyporolithon patena (Hook . et Harv . ) Mason . G.pristoides recrui t ment in the sublittoral fri nge was enhanced with the exclusion of grazers . However, successful recruits were displaced due to smothering by articulated corallines (e.g. Corallina sp. and Jania sp. ) . G.pristoides is largely restricted to cracks and crevices in the rock, and also occurs on a large proportion of the available shells of the limpet Patella oculus Born., and to a lesser extent, shells of the barnacle Tetraclita serrata. G.pristoides recruitment was significantly enhanced by the exclusion of grazers (using toxic antifouling paint barriers). G.pristoides recruitment within the exclusion plots was significantly greater on artificially attached limpet shells (almost 100% cover) than on rock surfaces (20-30% cover), which occurred largely within cracks and crevies in the rocky substratum. ly attached to limpet G.pristoides plants are significantly more strongand barnacle shells than to rock and epilithic encrusting corallines (Lithothamnion sp.). Removal of G.pristoides from limpet shells revealed pits of a uniform size in the surface of the shells, into which the rhizoidal attachment organs of the seaweed penetrate. It is concluded that the horizontal distribution of G.pristoides is largely controlled by grazers (and "escapes" from grazing) and resistance to dislodgement by wave action. Based on present results, and considering some of the socio-economic factors associated with the Gelidium industry in South Africa, suggestions are made concerning the management and long-term maintenance of G.pristoides resources in the eastern Cape.
  • Full Text:
  • Date Issued: 1987

Determination of distinctness among citrus cultivars using biochemical and molecular markers

  • Authors: Carstens, Karin
  • Date: 1995
  • Subjects: Citrus fruits -- South Africa , Citrus fruits -- Research -- South Africa , Citrus fruits -- Analysis
  • Language: English
  • Type: Thesis , Masters , MSc
  • Identifier: vital:4022 , http://hdl.handle.net/10962/d1004082 , Citrus fruits -- South Africa , Citrus fruits -- Research -- South Africa , Citrus fruits -- Analysis
  • Description: Citrus is among the most important fruit crops worlstwide, and therefore the preservation and improvement of citrus germplasm is of the essence. Citrus breeders are often faced with the difficulty of distinguishing between new and existing cultivars because of the ambiguous nature of morphological traits due to environmental influences and error in human judgement. The protection of new varieties is very important to the breeder. New varieties cannot be patented in South Africa, but it can be protected by Plant Breeders' Rights, only if it is genetically distinguishable and significantly different economically from existing varieties. Cultivars in four genera (c. sinensis, C. paradisi, C. grandis and C. reticulata) included in the Citrus Improvement Programme (CIP) or cultivars awaiting recognition of Plant Breeders' Rights by the International Union for the Protection of New Plant Varieties (UPOV) were analyzed with Isoenzymes, Restriction Fragment Length Polymorphism (RFLP) and Random Amplified Polymorphic DNA (RAPD). Five enzyme systems (PGM, PGI, MDH, GOT and IDH) were analyzed and founded to be suitable for grouping together cultivars belonging to the same genera. It was not suited for routine discrimination of cultivars in a particular genus. RFLP studies were conducted on five grapefruit cultivars, using cDNA clones from a genomic library of Rough Lemon. RFLP studies were valuable for the discrimination of closely related cultivars which probably originated from a common ancestor by bud mutations. This technique was, however, abandoned due to its biohazardous nature and replaced by the PeR-based Random Amplified Polymorphic DNA. RAPDs are easy to perform and gave promisin& results which were exploited to reveal polymorphisms between cultivars within the various groups. Although the interpretation of data produced by this method is often suspicious, it is the best method currently available for cultivar identification. It can playa complementary role in the protection of new varieties when classical morphological interpretation of differences is not capable of determining sufficient distinctness for the awarding of Plant Breeders' Rights.
  • Full Text:
  • Date Issued: 1995

An exploratory investigation into an Integrated Vulnerability and Patch Management Framework

  • Authors: Carstens, Duane
  • Date: 2021-04
  • Subjects: Computer security , Computer security -- Management , Computer networks -- Security measures , Patch Management , Integrated Vulnerability
  • Language: English
  • Type: thesis , text , Masters , MSc
  • Identifier: http://hdl.handle.net/10962/177940 , vital:42892
  • Description: In the rapidly changing world of cybersecurity, the constant increase of vulnerabilities continues to be a prevalent issue for many organisations. Malicious actors are aware that most organisations cannot timeously patch known vulnerabilities and are ill-prepared to protect against newly created vulnerabilities where a signature or an available patch has not yet been created. Consequently, information security personnel face ongoing challenges to mitigate these risks. In this research, the problem of remediation in a world of increasing vulnerabilities is considered. The current paradigm of vulnerability and patch management is reviewed using a pragmatic approach to all associated variables of these services / practices and, as a result, what is working and what is not working in terms of remediation is understood. In addition to the analysis, a taxonomy is created to provide a graphical representation of all associated variables to vulnerability and patch management based on existing literature. Frameworks currently being utilised in the industry to create an effective engagement model between vulnerability and patch management services are considered. The link between quantifying a threat, vulnerability and consequence; what Microsoft has available for patching; and the action plan for resulting vulnerabilities is explored. Furthermore, the processes and means of communication between each of these services are investigated to ensure there is effective remediation of vulnerabilities, ultimately improving the security risk posture of an organisation. In order to effectively measure the security risk posture, progress is measured between each of these services through a single averaged measurement metric. The outcome of the research highlights influencing factors that impact successful vulnerability management, in line with identified themes from the research taxonomy. These influencing factors are however significantly undermined due to resources within the same organisations not having a clear and consistent understanding of their role, organisational capabilities and objectives for effective vulnerability and patch management within their organisations. , Thesis (MSc) -- Faculty of Science, Computer Science, 2021
  • Full Text:
  • Date Issued: 2021-04

Palynology and palaeo-environment of Pleistocene hyaena coprolites from an open-air site at Oyster Bay, Eastern Cape coast, South Africa

  • Authors: Carrion, J S , Brink, J S , Scott, Lucy E P , Binneman, J N F
  • Date: 2000
  • Language: English
  • Type: Article
  • Identifier: vital:7000 , http://hdl.handle.net/10962/d1008357
  • Description: Hyaena coprolites in a soil horizon at Oyster Bay, Eastern Cape coast, South Africa, were found associated with abundant, early Last Glacial vertebrate faunal remains that were apparently accumulated by brown hyaenas and prehistoric humans. Artefacts of the Howieson's Poort sub-stage of the Middle Stone Age occur in the same soil. Although direct association between the different finds cannot be demonstrated, there is evidence to suggest that they are broadly contemporaneous. Pollen assemblages in the coprolites were dominated by Myrica and, to a lesser extent, Stoebe-Elytropappus type and Poaceae. Comparison with the modern pollen spectrum suggests that the past environment differed markedly from the current. The presence of Stoebe-Elytropappus, in particular, is considered to indicate a displacement of vegetation zones to lower altitudes. Both fossil pollen and fauna suggest a landscape with a complex mosaic of vegetation indicative of overall cooler, more inland conditions than today.
  • Full Text: false
  • Date Issued: 2000

An exploratory study of the factors that influence the retention of managers in small to medium business enterprises

  • Authors: Carr, Nathan Lars Armitage
  • Date: 2013
  • Subjects: Employee retention -- South Africa -- Eastern Cape Small business -- South Africa -- Eastern Cape Executives -- South Africa -- Eastern Cape Human capital -- Management Personnel management -- South Africa -- Eastern Cape Organizational effectiveness -- South Africa -- Eastern Cape
  • Language: English
  • Type: Thesis , Masters , MBA
  • Identifier: vital:813 , http://hdl.handle.net/10962/d1007740
  • Description: Integrative Summary: Small to Medium Business Enterprises (SME's) are widely recognised as the driver of economic growth. SME's are responsible for employing large sections of the working population and, in doing so, facilitate the development of skills for many thousands of workers. Whilst SME's may differ (according to various definition criteria such as size or turnover) from other types of organisation, they share one common denominator across all organisations: their overall effectiveness depends largely on the individual and collective people that make up the organisation -their employees. In this context the central question relevant to the research is "how do SME's retain their valued employee managers?" A quantitative research method was applied in the research. Data was collected by way of a structured self-administered survey questionnaire designed from a post positivist paradigm. The survey was constricted by way of modifying and adapting previous surveys designed to investigate factors that influence staff retention, to be relevant to managers employed by SME's. The sample consisted of 35 managers employed by SME's in and around East London in the Eastern Cape, South Africa. The results of the research give rise to a number of clear indicators on the key retention factors of employee managers. Based on the research results SME's that want to have the best chance of retaining their employee managers need strong and effective leadership within the organisation, must address soft organisational factors that are conducive to an open and trusted working environment and the roles of managers must have inherent job factors that allow a sense of freedom to plan and execute tasks autonomously. Economic factors such as pay and financial benefits were identified through the research as being the least important factor when it came to manager retention. These conclusions provide SME owners and senior managers with insight into the factors that are most likely to influence their ability to retain employee managers.
  • Full Text:
  • Date Issued: 2013

Foraging in a dynamic environment: movement and stable isotope ecology of marine top predators breeding at the Prince Edward Archipelago

  • Authors: Carpenter-Kling, Tegan
  • Date: 2020
  • Subjects: Marine ecology , Stable isotope tracers , Estuarine ecology
  • Language: English
  • Type: Thesis , Doctoral , DPhil
  • Identifier: http://hdl.handle.net/10948/49049 , vital:41596
  • Description: Marine ecosystems are experiencing rapid changes due to climate change. The associated temporal and spatial changes in resource distribution impacts on the foraging behaviour of marine top predators. If these changes negatively affect the ability of marine predators to forage efficiently, there may be dire consequences for their populations. However, evidence of foraging plasticity during adverse conditions, or generalist foraging behaviour, can allow inference about the resilience of species to environmental change and provide essential knowledge towards effective and proactive conservation measures. I examined plasticity in the trophic ecology of 12 marine predator species breeding on Marion Island, southern Indian Ocean, over three years (2015 – 2018), a period characterized by pronounced environmental variability. Firstly, I correlated behavioural states inferred along the GPS tracks of incubating wandering, grey-headed, sooty and light-mantled albatrosses to environmental variables that are indicative of biologically productive oceanographic features. Secondly, I analysed δ13C and δ15N blood values in 12 marine predator species (the afore-mentioned albatrosses as well as king, gentoo, macaroni and eastern rockhopper penguins, northern and southern giant petrels and Antarctic and sub-Antarctic fur seals) over two seasons: summer and autumn. My results revealed that the foraging behaviour of all the species is, to some degree, either plastic (temporally variable isotopic niche) or general (large isotopic niche which remained similar over time), except for the king penguin (small isotopic niche which remained similar over time), a known foraging specialist. Furthermore, despite their dynamic foraging behaviour, resource partitioning among the predators was maintained over time. Due to the ease and relatively low cost of collecting tissues for stable isotope analysis it has the potential to be a powerful tool to monitor the trophic ecology of marine predators. I thus used my simultaneously collected dataset of GPS tracks with the stable isotope blood compositions to investigate some of the assumptions underlying the inferences made from marine predator δ13C and δ15N blood values. I reconstructed species- and guild- specific δ13C and δ15N isoscapes for eight seabird species. Following this, I coupled individual-based movement models of northern giant petrels with global marine isotope models to explore the sensitivity of tissue δ13C values to a range of extrinsic (environmental) and intrinsic (behavioural, physiological) drivers. My results demonstrate the strong influence of reference isoscapes on the inference of stable isotope compositions of marine predators. Furthermore, I show that caution should be used when using non-species-specific or temporally inaccurate isoscapes. I furthermore demonstrate that biological interactions, such as competition for food resources, either past or present, as well as spatio-temporal distribution of food patches strongly influence the foraging behaviour of marine predators. These findings highlight the importance of integrating biological interactions in species distribution models which are used to predict possible distributional shifts of marine predators in the context of global changes. My thesis further developed previously available methods and presents a novel approach to investigate sources of variance in the stable isotopic composition of animals’ tissues.
  • Full Text:
  • Date Issued: 2020

Foraging ecology of the gentoo penguin, pygoscelis papua, at Marion Island

  • Authors: Carpenter-Kling, Tegan
  • Date: 2016
  • Subjects: Gentoo penguin -- Food
  • Language: English
  • Type: Thesis , Masters , MSc
  • Identifier: http://hdl.handle.net/10948/4912 , vital:20766
  • Description: The distribution and subsequent availability of marine predators’ prey is highly variable and is linked to fluctuating oceanographic parameters. It is well documented that annual breeding success of seabirds is related to the temporal availability of prey. Knowledge of a seabird’s diet and at sea distribution is therefore critical in deducing the effect of a fluctuating environment on a seabirds’ population and, furthermore, to understand seabirds role in the environment. The gentoo penguin population at sub-Antarctic Marion Island experienced a decline of 52% between 1994 and 2012. It has been speculated that long term changes in the local marine environment, due to a southward shift of the sub-Antarctic Front (SAF), and subsequent changes in prey availability is the ultimate causal factor. Therefore, this thesis investigates the temporal variation in the diet these birds over three years, through the use of stomach content samples. It then investigates whether the composition of the diet has changed over the long term (approximately 18 years). Additionally, the at sea distribution of these birds was investigated using temperature-depth recorders (TDRs) and global positioning system (GPS) devices. This study represents the first to investigate variation in the diet over three years and over the long term. It is also the first study to track these birds fine scale movement. Over three years, the diet exhibited a high degree of variability. The birds primarily foraged on the fish, Lepidonotothen larseni and the crustaceans, Nauticaris marionis and Euphausia vallentiniy. Over three years, L. larseni became increasingly more important during the breeding season. This was attributed to an increase in availability of these fish during this time, as this time corresponded to the transition of these fish from the larval pelagic phase to the benthic adult phase. Furthermore, the proportions of N. marionis and E. vallentini in the diet varied significantly among years. This variation is possibly a result of the highly variable latitudinal position of the SAF. The diet changed over the long term. There was significantly less N. marionis and more E. vallentini in the diet during more recent years. The long term southward shift of the SAF is considered to be a leading cause of these significant changes in the diet. The shallow inter-island shelf between Marion and Prince Edward Island was an important foraging area possibly due to predictable prey resources. In addition, these birds exhibited an important and possibly unique foraging strategy. They performed short self-maintenance trips where after they return to land to roost for the night. The following day these trips were followed by a longer foraging trip that was followed by chick provisioning. This strategy is unique among seabirds longer trips are associated with self-maintenance and not chick provisioning. This study has provided important knowledge of the foraging ecology of the gentoo penguin at sub-Antarctic Marion Island. It highlights the necessity for continuation of diet and tracking studies of these birds if we are to fully understand the ultimate factors that are causing the decline in their breeding success and population numbers.
  • Full Text:
  • Date Issued: 2016

An economic analysis of eradicating alien vegetation as an alternative to conventional water supply schemes: a case study of the Krom and Kouga

  • Authors: Carpenter, Robert Charles
  • Date: 1999
  • Subjects: Alien plants -- South Africa , Water-supply -- South Africa , Kouga River (South Africa)
  • Language: English
  • Type: Thesis , Masters , MCom
  • Identifier: vital:1000 , http://hdl.handle.net/10962/d1002735 , Alien plants -- South Africa , Water-supply -- South Africa , Kouga River (South Africa)
  • Description: South Africa is classified as an arid to semi-arid region and water scarcity in South Africa has been identified as a key factor limiting socioeconomic development in the next century. In the Algoa region, the total urban plus agricultural water demand is expected to exceed the supply by the year 2005. The Kouga Working for Water Project aims to increase the base flow to the existing dams which supply the Port Elizabeth metropolitan area through the eradication of invasive alien trees in the riparian areas of the Krom and Kouga catchments. This thesis analyses the economic efficiency of optimal catchment management as a water supply scheme. A cost-benefit analysis is conducted for the Kouga eradication programme, and its desirability is evaluated in terms of the net present value (NPV) and the internal rate of return (IRR) criteria. In order to compare the cost-e~i.ciency of the eradication programme to alternative water supply augmentation schemes the Unit Reference Value (URV) is calculated for the project. The NPV for the project is calculated using a discount rate of 7% and amounts to nearly R24 million. This positive NPV indicates that the project is economically desirable in that it results in the improvement of human welfare. The IRR decision rule supports this finding. The URV of the eradication scheme is found to be competitive to that generated by more conventional schemes. Considered in the evaluation of the project are a host of environmental benefits that accompany the eradication of alien vegetation. This is in contrast to alternative schemes which result in several detrimental impacts to the environment. The economic analysis concludes that the eradication of alien vegetation is an efficient and desirable alternative water supply augmentation scheme. The conclusions drawn from the analysis of the eradication programme in this catchment area can be extended to other catchment areas, with the aim of promoting the most efficient supply of water.
  • Full Text:
  • Date Issued: 1999

The prevalence of pediatric metabolic syndrome—a critical look on the discrepancies between definitions and its clinical importance

An investigation into the insect ecology of citrus orchards, with special reference to citrus mussel scale (Lepidosaphes beckii newm.)

  • Authors: Carnegie, Alistair John Michael
  • Date: 1955
  • Subjects: Citrus -- Diseases and pests -- South Africa -- Eastern Cape , Lepidosaphes
  • Language: English
  • Type: Thesis , Masters , MSc
  • Identifier: vital:5905 , http://hdl.handle.net/10962/d1014637
  • Description: In the course cf the last fifteen years the general lnsect ecology of citrus orchards in the Eastern Cape has provided the subject matter of four theses presented for the degree of M.Sc. of Rhodes University. The false codlin moth, Argyroploce leucotreta Meyr., formed the subject of a thesis by Horne in 1939. Then in 1941 the same insect formed the subject matter of a thesis by Harris. The general ecology of a citrus orchard, with special regard to the biological control of citrus red scale, Aonidiella aurantii Mask., was the subject matter of Whitehead's thesis in 1948. This was a much more general investigation than the preceding two theses, and touched on many more aspects of citrus ecology. Another thesis dealing with more general citrus ecology was that of Smithers in 1953.
  • Full Text:
  • Date Issued: 1955

Public relations in community work : a public relations programme for direct service organisations

  • Authors: Carmichael-Kathan, Averil Margaret
  • Date: 1992 , 2012-11-28
  • Subjects: Social service -- Public relations -- Research , Community organization -- Research , Social service -- Research
  • Language: English
  • Type: Thesis , Masters , MSocSc
  • Identifier: vital:692 , http://hdl.handle.net/10962/d1006375 , Social service -- Public relations -- Research , Community organization -- Research , Social service -- Research
  • Description: The community work method of social work is a method requiring creativity, application of specialised skills and knowledge, sound planning and administration and a persuasiveness to reach the various sectors of the community in order to accomplish broad based goals. Public relations is an occupation that has a sound body of literature and theory, a code of ethics or conduct, a host of tools and methods and also requires sound planning and administration, bound together with persuasiveness to reach the various publics in order to accomplish goals affecting image, quality of service rendering and marketing of services. The present study was concerned with identifying the commonalities and the differences between the profession of community work and the occupation of public relations in order to enhance the content of community work theory for practical application by community workers. The differences between the two would, in fact, teach content to community work. It was hypothesised that public relations has a necessary function and is an occupation that can be internalised with and applied to community work for the effective marketing of organisational services. A model for incorporating public relations into community work was designed and implemented in a direct service welfare organisation with positive results. This design is applicable to other direct service welfare organisations with innovative and flexible management teams. The results of an empirical research study, making use of random sampling and questionnaires, was analysed. The results indicated that public relations and community work were comparable entities with reference to knowledge bases, values, skills, tools, methods, techniques, ethics and programmes. A third group of respondents emerged in this study - community workers practising public relations firmly within the realm of community work. This group advocated the use of marketing and communication strategies in applying the community work method effectively. The primary difference to emerge from the work research was one of emphasis in applying methods and subsequently, community work can learn a great deal from these differences which will enhance service rendering correspondingly. The culmination of this study led to several highly relevant conclusions and recommendations for welfare organisations in a Post-apartheid South Africa. The most worthwhile conclusion was that community work has a great deal to learn from public relations, and that they are combinable entities at every level. , KMBT_223
  • Full Text:
  • Date Issued: 1992

Monolingualism and its meaning in two KwaZulu-Natal high schools

  • Authors: Carlyle, Jacqui
  • Date: 2017
  • Subjects: Monolingualism -- South Africa , Monolingualism -- South Africa -- Case studies , Language awareness -- South Africa , Language and education -- South Africa , School children -- South Africa -- Attitudes , School children -- South Africa -- Attitudes -- Case studies , African languages -- Study and teaching -- South Africa -- Attitudes
  • Language: English
  • Type: Thesis , Masters , MA
  • Identifier: http://hdl.handle.net/10962/6543 , vital:21135
  • Description: This study reports on the identity and attitudes of monolingual English speakers (MES) at two high schools in Durban, South Africa, in relation particularly to the role and meaning of monolingualism. Two bodies of data are used to investigate the attitudes of MES and are oriented towards four variables: English, African languages (particularly Zulu), monolingualism and plurilingualism. The attitudes to these variables reveal the impact on identity of language usage in Durban, and negotiations of the participants in trying to mitigate or justify attitudes that are counter to the embracing of diversity encouraged in modern South Africa. First, an attitude questionnaire provides quantitative data that is subjected to analysis, including a chi-squared test. Second, a narrative elicitation interview provides qualitative narrative data that is analysed in relation to APPRAISAL theory. Both analysis types are used to ascertain the presence of a monolingual mindset in the scholars’ responses, as well as to capture the ideological forces to which they are subjected as monolingual English speakers in the unique multilingual setting of Durban. In essence, the data points to a discourse of compromise and unease on the part of the participants - as they juggle with the effects of an English-centric monolingual mindset, and a more pervasive pluralism that embraces the Rainbowism of ‘the new South Africa’. This discourse of compromise is characterized on one side by insecurity and dissatisfaction with the language in education policy, and well as the monolingual upbringing of MES in Durban, and a lack of Language other than English (LOTE), in particular, Zulu. This side of the compromise also portrays a pro- plurilingual orientation, a positive valuation of knowing a LOTE and of plurilingual people. Here, however, the manifestation of the ‘other side’ of the compromise appears as the MES characterize plurilingualism as exceptional and too difficult, and language learning at school as having a negative impact on academic success. Alongside this is a normalization of English and othering of African languages in practical situation. English is also promoted as the language of unity and economic and academic progress or success, while the material value of African languages is questioned.
  • Full Text:
  • Date Issued: 2017

A critical analysis of the application of total quality management principles in two schools

  • Authors: Carlson, Brian Kenneth
  • Date: 1996
  • Subjects: Total quality management School management and organization -- Case studies School management and organization -- South Africa
  • Language: English
  • Type: Thesis , Masters , MEd
  • Identifier: vital:1472 , http://hdl.handle.net/10962/d1003353
  • Description: In recent years, the principles of Total Quality Management, developed by Edwards Deming and others and used with varying degrees of success in the business world, have been used in schools as part of the process to transform education in terms of school management and classroom learning. This research grew out of my experiences when St. Andrew's Preparatory School participated in a Total Quality Management training programme which highlighted for me the problems and the benefits of such training. This research was undertaken, therefore, to find out how two other schools - one a high school in Grahamstown and the other a high school in Clarke County, U.S.A. had responded to similar training. Open ended questionnaires were used and the responses were analyzed to detect patterns of thoughts, feelings and attitudes, particularly in terms of human relationships at the school and with regard to various components of school culture. Comparisons were also made between the responses from the two schools, and the findings were compared with the claims made for TQM by the theorists and other educational practitioners who have ventured into TQM in their schools. The research findings indicate that Total Quality Management training had a positive impact on the participating schools but that there are problems associated with its adaptation for education. Given the necessary leadership commitment, however, these problems are not insurmountable. Total Quality Management may well be able to contribute towards the restructing of education which seems to be more and more urgently needed both in South Africa and in their countries.
  • Full Text:
  • Date Issued: 1996

Molecular simulations of potential agents and targets of Alzheimer’s disease

  • Authors: Carlisle, Tanya
  • Date: 2020
  • Subjects: Alzheimer's disease -- Treatment , Alzheimer's disease -- Molecular aspects , Amyloid beta-protein precurs , Amyloid beta-protein
  • Language: English
  • Type: text , Thesis , Masters , MSc
  • Identifier: http://hdl.handle.net/10962/140025 , vital:37825
  • Description: The World Alzheimer Report statedin 2016 that approximately 46.8 million people were living with dementia and this figure is expected to triple by 2050. Alzheimer’s Disease was discovered to be a precursor to dementia in 1976 and since then efforts to understand Alzheimer’s have been prioritized. To date, there are very few effective forms of treatment for Alzheimer’s, many are known to offer only mild calming of the symptoms and have side effects such as diarrhea, nausea, loss of appetite and sleep disturbances. This has been due to lack of understanding on how Alzheimer’s is caused. With the two main hallmarks of the disease now being more understood it has opened the doorway into the discovery of new treatments for this disease. This study focuses on the hallmark involving the aggregation of the β-amyloid protein to form plaques surrounding the neurons of the brain. Copper, Zinc and Iron have also been found in high concentrations in and surrounding these plaques. This study focused on the screening of the South African Natural Compound database (SANCDB) to discover hits that have potential destabilizing action against the Beta-amyloid aggregate. If one of these compounds could prove to have destabilizing action on the aggregate it could open the doorway to new potential forms of treatment. Over 700 SANCDB compounds were docked, and the top hits were taken to molecular dynamics to further study the interactions of the compounds and the aggregate. However, the hits identified had strong binding to the aggregate causing it to become stable instead of the desired effect of destabilizing the structure. This information, however, does not rule out the possibility of these compounds preventing the formation of the aggregates. Further, interactions of copper with β-amyloid and copper were determined by solubilizing the aggregate and introducing copper ions in a dynamics simulation. Possible interactions between copper and the methionine residues were visualised.
  • Full Text:
  • Date Issued: 2020

Member perspectives on the role of social capital in the success of the Heiveld Cooperative in the Northern Cape, South Africa

  • Authors: Carlisle, Juliet Hazel
  • Date: 2014
  • Subjects: Heiveld Cooperative , Human capital -- South Africa , Social capital (Sociology) -- Economic aspects -- South Africa , Agriculture, Cooperative -- South Africa , Cooperative marketing of farm produce -- South Africa , Rooibos tea industry -- South Africa
  • Language: English
  • Type: Thesis , Masters , MBA
  • Identifier: vital:825 , http://hdl.handle.net/10962/d1011734 , Heiveld Cooperative , Human capital -- South Africa , Social capital (Sociology) -- Economic aspects -- South Africa , Agriculture, Cooperative -- South Africa , Cooperative marketing of farm produce -- South Africa , Rooibos tea industry -- South Africa
  • Description: The aim of this qualitative study is to explore the perspectives of current members of the cooperative regarding the role of social capital in the success of the Heiveld Cooperative on the Suid Bokkeveld in the Northern Cape, South Africa (SA). This cooperative has been cited by several researchers as being successful for various reasons, including the existence of a marketable resource, a steady increase in production, and certification through Fairtrade, resulting in an export market. Social capital, as a contributing factor to the success of the cooperative, has not however previously been investigated in depth. In light of the unique success of this cooperative, it is important to obtain an in-depth understanding of the role of social capital, if any, in its success, particularly in the formation and day-to-day operation of the cooperative. With a particular focus on the members’ perspectives of the cooperative, this qualitative research adopted a case study approach to explore and to gain multiple and subjective understanding of the role played by social capital in the success of the Heiveld Cooperative. This may assist the organisation under study, as well as similar initiatives, in strategically harnessing the benefits of social capital as a resource in future. This report has three interrelated sections. The first part is an academic paper, which includes a condensed literature review, research methods, results and discussions. The second part is an expanded literature review, while the third section details the research methods. It is vital to note that these sections are separate, but interrelated. Convenience sampling was used to identify current members of the cooperative who participated in this exploratory qualitative study. Four heterogeneous focus group discussions, with a total of 44 members of the Heiveld Cooperative in the Suid Bokkeveld, were conducted. The focus groups were heterogeneous, as they included ordinary members, founding members and committee members. A guideline with questions based on the theory of social capital was developed, and used to initiate or stimulate discussion among the members of the cooperative in order to address the key research question, namely: What was the role of social capital, if any, in the success of the Heiveld Cooperative in the Northern Cape as perceived by current cooperative members? The primary source of data was collected through focus group discussions, while secondary data was obtained from documents in a form of internal reports and papers written for the Heiveld Cooperative. Data was analysed using open coding and constant comparison techniques in order to induce emerging themes from the data. Findings of this study revealed that social capital played a major and influential role during the inception and also in the successful operation of the Heiveld Cooperative, by bonding and bridging not just between individual members, but also between communities, trading partners and other collaborators. Another key finding of this study is that social capital was also critical in enhancing supportive knowledge sharing, and the promotion of pride and shared identity, which the study identifies as aspects of cognitive social capital. Interestingly, the cognitive dimension of social capital in the Heiveld Cooperative has contributed to the weakening of social capital, as evident in claims related to lack of transparency and procedural injustice. Last, but not least, leveraging the sense of community has also been useful in promoting collective efficacy, strengthening familial togetherness, and enhanced democratisation of decision-making. Diminished trust, based on perceived oligarchy and nepotism is gradually weakening relational social capital. Findings in this study are illuminated using the social capital theory described by Nahapiet and Ghoshal (1998) to depict the social, cognitive and relational aspect of social capital that are at work at Heiveld Cooperative. Additionally, the social network theory by Hoppe and Reinelt (2010) is used to highlight the systemic view of social capital, which embraces the structural, relational and cognitive nature not only internal to but also between networks of the cooperative. Recommendations are provided to ensure social capital is harnessed, rather than undermined. These include the need to promote the processes of learning, monitoring and discussion that have been implemented; harnessing the benefits of bonding and bridging social capital; leveraging the sense of community and applying a more systemic view of social capital; and addressing perverse aspects of social capital such as nepotism and oligarchy that have been identified.
  • Full Text:
  • Date Issued: 2014

The functions of narrative : a study of recent novelistic nonfiction

  • Authors: Carlean, Kevin John
  • Date: 1988
  • Subjects: Reportage literature -- History and criticism , Nonfiction novel
  • Language: English
  • Type: text , Thesis , Masters , MA
  • Identifier: vital:2176 , http://hdl.handle.net/10962/d1001827
  • Description: Since Truman Capote's In Cold Blood: A True Account of a Multiple Murder and its Consequences was published in 1965, there have been many attempts to define and explain the phenomenon of the "non-fiction novel" as a unified narrative genre. Some of these attempts have been highly theoretical and scholarly, but most have been rather loose definitions referring to an extremely wide range of diverse factual narratives. Over the years, so many different works have been called "non-fiction novels" that it now seems as if the notion of such a unified genre is questionable. Surely it is not generically useful to say that such functionally distinct works as Oscar Lewis's La Vida: A Puerto Rican Family in the Culture of Poverty (1967) and Hunter S. Thompson's Fear and Loathing in Las Vegas: A Savage Journey to the Heart ot the American Dream (1971) belong in the same narrative category. The purpose of this study is to show that many of the works routinely referred to as "non-fiction novels" perform fundamentally different narrative functions and do not belong together in a unified genre. Roman Jakobson's model of communication and his notion of the "dominant function" are used to identify three functional categories into which the narratives discussed in the study logically fall: first, there are predominantly sociological works in which the referential function is the most important element of the communication; second, there are predominantly journalistic works in which the opinions of the writer or emotive function constitute the central narrative concern; and thirdly, we have works performing a dominant novelistic or aesthetic function in the sense that the secondary meanings and themes implied are the most important elements communicated. The thesis follows the following structure. In the introductory chapter, a critique of some of the major generic theories of the "non-fiction novel" as unified genre is offered. The purpose here is not to caricature what are sometimes extremely sophisticated studies. (Indeed, in my own analysis of texts, I am often indebted to the critical insights of the scholars whose theories I question in the introduction.) My purpose is merely to show that the corpus of works each writer refers to can be divided more logically between different dominant narrative functions. The introduction ends with a more detailed explanation of the adaptation of Jakobson's notion of "the dominant" and how it relates to the functional categories identified. Chapter 2 offers analyses of a group of documentary narratives that perform a dominant sociological function but have often been referred to as "non-fiction novels." The chapter starts with an analysis of James Agee's Let Us Now Praise Famous Men (1941), a text widely regarded as the first real American example of the "genre." This is followed by an examination of the anthropological works of Oscar Lewis: Five Families: Mexican Case Studles in the Culture of Poverty (1959), The Children of Sanchez: Autobiography of a Mexican Family (1964), Pedro Martinez: A Mexican Peasant and his Family (1964) and La Vida: A Puerto Rican Family in the Culture of Poverty. I conclude the chapter with an analysis of the recent sociological works of Studs Terkel: Division Street: America (1968), Hard Times: An oral History of the Great Depression (1970) and Working: People talk about what they do all day and how they feel about what they do (1974). In Chapter 3, the notion of subjective participation journalism is explained. This is followed by an analysis of three of the most famous and creative of the works that fall into this functional category: Hunter S. Thompson's Hell's Angels: The Strange and Terrible Saga of an Outlaw Motorcycle Gang (1966), Michael Herr's Vietnam classic, Dispatches (1977), and Norman Mailer's account of a famous protest march, The Armies of the Night: History as a Novel, The Novel as History (1968). Chapter 4 offers a discussion of three works that perform a dominant novelistic function in the realistic tradition of Dostoevski's Crime and Punishment. All three are based on actual murder cases, but the facts of the stories are subordinated to the novelistic themes the author wishes to abstract. They are: Meyer Levin's Compulsion (1957), Mailer's The Executioner's Song (1979) and Capote's In Cold Blood. From this outline, it may appear as if the study is loaded in favour of the sociological works discussed in Chapter 2. This is intentional because, although many critics have referred to them as "non-fiction novels", very little systematic and detailed analysis of these works as a corpus has been forthcoming. This long chapter is an attempt to redress the balance.
  • Full Text:
  • Date Issued: 1988

Drama in South African secondary schools meeting the challenges of educational change

  • Authors: Carklin, Michael Larry
  • Date: 1996
  • Subjects: Drama in education -- South Africa
  • Language: English
  • Type: Thesis , Masters , MA
  • Identifier: vital:2133 , http://hdl.handle.net/10962/d1002365 , Drama in education -- South Africa
  • Description: South Africa is undergoing fundamental transformation at all levels of government and civil society, requiring a firm commitment to redressing the legacy of apartheid and to the development of South Africa's people. Part of this commitment is to undertake research which complements transformation processes, investigating the most appropriate ways to meet the challenges posed by such change. This study examines the potential of drama in the secondary school to meet key educational challenges, motivating strongly for the inclusion of drama as part of the formal curriculum in all schools. Social transformation has been greatly influenced by policy such as the Reconstruction & Development Programme (RDP) and subsequent Government White Papers which identify the need to develop South Africa's human resources as crucial. It is in this light, arid in the context of great disparity that exists across the education spectrum, that learning experiences of high quality must be provided in schools. It is argued that drama, as an lift form and an educational medium, is able to provide such qualitatively sound learning experiences because it is essentially learner-centered, experiential and holistic, offering unique ways of knowing, understanding and gaining insights. However, the classroom drama experience needs careful conceptualisation itself, particularly in view of the fact that life experiences of pupils are characteriseg by multiplicity and diversity within a new era of social and cultural mixing, as well as increased global interaction through, for example, the mass media and the internet. This study thus argues from a post-structuralist perspective, which embraces notions of multiplicity, proposing a reconceptualisation of the classroom drama experience that challenges the oppositional or binary perspectives that have previously characterised the way we think about drama and education. Example~ include art versus utilitarianism; process versus product; drama versus theatre. Investigating the classroom drama experierice in the light of developments in postmodern theatre, this study proposes that classroom drama should be seen as a form of theatre itself and suggests the term theatricalisaction to describe this classroom-theatre process which is based on action, reflection, experience and creative expression. It becomes a theatre of activity or an activating theatre. In this light classroom drama is considered in a specifically South Mrican context. In particular, this study examines the ways in which the following contexts impact upon the drama experience: the education system, the place of the arts within that system, and cultural and linguistic diversity in the classroom. Drawing on policy documentation, conference proceedings and studies that have been carried out in multiculturalism and multilingualism, the specific educational challenges facing South Africans are identified. In further exploring the potential of drama to meeting these challenges, this study documents the results of surveys conducted with drama teachers and with ~students who have studied drama as one of their formal subjects, highlighting in particular their perceptions, perspectives and experiences regarding the aims and value of drama education. Finally, in light of the information gained from teachers and learners, and of the concepts and contexts investigated, this thesis considers the ways in which the drama experience can contribute to meeting three primary educational challenges: the building of a culture of learning; the development and empowerment of pupils; and the embracing of cultural and linguistic diversity. This study concludes that drama is able to contribute significantly to educational change because of the teaching and learning processes it offers as an art form, and in particular, a theatre form. It is such a participatory, democratic classroom-theatre which provides a teaching and learning approach that should be at the core of transformation.
  • Full Text:
  • Date Issued: 1996

Chanzy: 10000 fans under the rain.

  • Authors: Carin, Sylviane
  • Subjects: McGregor, Chris--1936-1990 , Brotherhood of Breath (Musical group) , Clegg, Johnny , Mahotella Queens , Jazz musicians
  • Language: French
  • Identifier: vital:13508 , http://hdl.handle.net/10962/d1005771 , McGregor, Chris--1936-1990 , Brotherhood of Breath (Musical group) , Clegg, Johnny , Mahotella Queens , Jazz musicians
  • Description: Photocopied article from the French newspaper Charante Libre about a concert with Chris McGregor's Brotherhood of Breath, Johnny Clegg and the Mahotella Queens. "Arrived at 3pm, Clegg's first fans had to wait until 10:45pm to see him". There are also 2 pictures with the article. The top one shows Chris McGregor on stage playing piano in front of a huge crowd and the bottom picture shows the Mahotella Queens dancing on the stage.
  • Full Text:

McGregor: Ten years at Angoulême

  • Authors: Carin, Sylviane
  • Subjects: McGregor, Chris--1936-1990 , Brotherhood of Breath (Musical group) , Shepp, Archie , Jazz musicians
  • Language: French
  • Identifier: vital:13509 , http://hdl.handle.net/10962/d1005772 , McGregor, Chris--1936-1990 , Brotherhood of Breath (Musical group) , Shepp, Archie , Jazz musicians
  • Description: Photocopied article from the French newspaper Charente Libre about a concert in Angoulême, France, with Chris McGregor's Brotherhood of Breath and Archie Shepp. There is a picture of Chris McGregor playing the piano (left) with the Brotherhood of Breath and Archie Shepp playing the tenor saxophone (front row - center).
  • Full Text:
  • Disclaimer
  • Privacy
  • Copyright
  • Contact