Suitability of the leaf-mining fly, Pseudonapomyza sp. (Diptera: Agromyzidae), for biological control of Tecoma stans L. (Bignoniaceae) in South Africa
- Authors: Madire, Lulama Gracious
- Date: 2010
- Subjects: Diptera -- Biological control , Bignoniaceae -- Biological control , Plants, Ornamental -- Diseases and pests , Agromyzidae
- Language: English
- Type: Thesis , Masters , MSc (Zoology)
- Identifier: vital:11790 , http://hdl.handle.net/10353/255 , Diptera -- Biological control , Bignoniaceae -- Biological control , Plants, Ornamental -- Diseases and pests , Agromyzidae
- Description: Tecoma stans (L.) Juss. Ex Kunth (Bignoniaceae) also known as yellow bells, has a native distribution from Northern Argentina, central America, Mexico and the Southern USA. In many warm climatic regions of the world, T. stans is commonly planted as an ornamental plant because of its yellow flowers, hence the name yellow bells, and pinnate foliage. As a result, this evergreen shrub has wide distribution in the tropical and subtropical parts of the western hemisphere. As is the case in many other parts of the world, T. stans was introduced into South Africa as an ornamental plant, but escaped cultivation and now invades roadsides, urban open spaces, watercourses, rocky sites in subtropical and tropical areas of five South African provinces; Gauteng, Mpumalanga, Limpopo, KwaZulu-Natal, Eastern Cape and neighboring countries. Tecoma stans has the potential of extending its range because its seeds are easily dispersed by wind. The purpose of this work was to carry out pre-release efficacy studies to determine the host specificity and suitability of Pseudonapomyza sp. (Diptera: Agromyzidae), a leaf-mining fly, as a biological control agent of T. stans. Available information suggests that the fly was brought to South Africa (SA) from Argentina in 2005. In that year a worker collected adult root feeding fleabeetles from T. stans and their eggs by collecting soil around the plants in the Argentinian Province of Jujuy, at San Pedro (24°12’592”S, 64°51’328”W). The soil was brought to the SA quarantine laboratory of the Agricultural Research Council, Plant Protection Research Institute (Weeds Division), Pretoria, and placed in a cage containing T. stans plants for flea-beetle larvae to emerge from the eggs. The Pseudonapomyza sp. flies which emerged from that soil were reared to produce a colony of flies used in the study reported here. The feeding behavior of Pseudonapomyza sp. adults is initiated by females which use their ovipositor to puncture holes in the leaf mesophyll and then they feed on the sap oozing from the holes. Since males have no means of puncturing the leaves, they feed from holes made by females. Eggs are laid singly into the tubular leaf punctures. Soon after hatching, the larva feeds on the leaf mesophyll tissue. As the larva feeds within the leaf it creates mines which eventually coalesce to form large blotches. The damaged leaf area reduces the photosynthetic potential of the plant especially when damaged leaves dry and fall off the plants. The potential of Pseudonapomyza sp. as a biocontrol agent is enhanced by the fact that it has a high level of fecundity and a short life cycle. As a result, its populations can build up rapidly to exert a significant impact on T. stans. Host-specificity tests undertaken on 35 plant species in 12 plant families showed that out of the 35 plant species tested, the fly was able to develop on T. stans only. Although Pseudonapomyza sp. adults fed on T. capensis, a South African indigenous ornamental shrub, no larval mines were observed on this plant. This suggests two possibilities; either females of Pseudonapomyza sp. do not oviposit on T. capensis or oviposition takes place but larvae cannot feed and develop on this plant. These studies indicate that this fly is sufficiently host-specific, and can be released against T. stans without posing any threat to either commercial or indigenous plant species grown in South Africa. Experimental designs simulating high populations of Pseudonapomyza sp. showed that the impact of leaf mining fly on T. stans can cause approximately 56 percent aboveground biomass reduction. Other concurrent studies have also showed that low and high density fly infestations can cause 23 percent and 48 percent belowground biomass reductions, respectively. Based on the available information, it appears that Pseudonapomyza sp. may have the potential to reduce the invasive capacity of T. stans in the affected areas. In order to exert more herbivore pressure on T. stans, it is suggested that agents belonging to other feeding guilds, such as root-, stem- and seed-feeding insects, be considered for release to complement the leaf-feeding of Pseudonapomyza sp. An application to release this fly in SA has been submitted to one of the two regulatory authorities.
- Full Text:
- Date Issued: 2010
Sustainable agricultural development in the Malawian smallholder agricultural sector: a case of Lilongwe District
- Authors: Chizimba, Martha
- Date: 2010
- Subjects: Food security -- Malawi , Poverty -- Malawi , Sustainable agriculture -- Malawi Case studies , Sustainable development -- Malawi Case studies , Agriculture -- Malawi
- Language: English
- Type: Thesis , Masters , M Soc Sc (Dev)
- Identifier: vital:11420 , http://hdl.handle.net/10353/365 , Food security -- Malawi , Poverty -- Malawi , Sustainable agriculture -- Malawi Case studies , Sustainable development -- Malawi Case studies , Agriculture -- Malawi
- Description: Even though agriculture is the backbone of Malawi‟s economy, food insecurity has remained a continuous threat among the poor. Until the 1980s, Malawi had been achieving national food security through an extensive system of agricultural inputs and marketing subsidies. However, these subsidies were removed and at the same time, the agricultural credit system collapsed. Consequently, agricultural productivity in Malawi remained low, poverty remained pervasive and food insecurity remains a main constraint to national and household food security. Therefore, the success of the agricultural sector in Malawi is very critical for raising the living standards and for food self-sufficiency. In this vein, the study hypothesized that Malawi can only achieve sustainable agricultural development if its agricultural policies are focused towards intensifying agricultural productivity through active participation of smallholder farmers. The major aim of the study was to contribute towards an improved understanding of how the issues of sustainable agricultural development have been addressed in Malawi and how they have influenced the lives of smallholder farmers. The analysis of the results revealed that even though what was implemented in the 1970s to early 1980s was financially unsustainable, but it provided some solutions to the fundamental challenges of smallholder development in Malawi. However, the liberalisations eroded whatever economic benefits achieved then. Never the less, the re-introduction of the agricultural input subsidies restored back the means of production leading to significant transformation of the country from a net importer to a net food exporter. On the other hand, although the agricultural input subsidy programme is being commended for having helped in achieving food security, the study revealed that the programme requires complementary services of credit, extension, research and market to support it. This will provide an exit strategy, which can enable the producers to sell their produce at higher prices sufficient enough for them to afford agricultural inputs without subsidies.
- Full Text:
- Date Issued: 2010
Sustainable growth of SME's
- Authors: Monks, Patrick Grant Standish
- Date: 2010
- Subjects: Success in business -- South Africa -- Port Elizabeth , Business enterprises -- South Africa -- Port Elizabeth
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:8627 , http://hdl.handle.net/10948/1488 , Success in business -- South Africa -- Port Elizabeth , Business enterprises -- South Africa -- Port Elizabeth
- Description: South Africa and more specifically Port Elizabeth is faced with many challenges with regard to economic growth and unemployment. It is generally acknowledged that the “Small to Medium Enterprises” (SME) are the largest employers in any economy, additionally SME’s are large contributors to the gross domestic product. Successful SME’s are the catalysts of the economy and over time they can develop into large enterprises. It is clear that in order for a country to have a strong and sustainable economy it needs to have a strong and successful SME sector. Unfortunately the South African SME sector performs relatively poorly in comparison with the SME sectors around the world (Herrington, Kew & Kew, 2009). With the knowledge of the importance of the SME sector to the economy and the knowledge that the South African SME’s are generally underperforming, this study will identify how to improve the relative success rate of the SME sector in Port Elizabeth South Africa. In order to achieve this, this study needs to identify why the SME sector is not performing on a par with other SME sectors from around the globe and what initiatives need to be implemented in Port Elizabeth that will enable its SME sector to perform at the same level or better than other SME sectors from around the globe. This study identifies that the South African SME’s are provided with a number of support initiatives. Some of these support initiatives have been very effective, while other support initiatives have been unsuccessful or have failed. This study concludes by identifying a number of areas that need improvement; of these areas two are identified as being critical to SME’s success and sustainability, these two areas are: · The need to make SME’s more aware of the government / business initiatives that are available; and · Establish more effective mentoring and coaching. In order to address these critical areas, the study suggests the use of an internet portal that can be used to coordinate all the activities between the mentors and the SME’s. This internet portal will be expanded to become the core information hub and collaboration centre for the flow of information between the SME’s and any of their stakeholders. Once all this information is centralised it will be a relatively simple process to measure the success rate of the SME’s and the effectiveness of the different mentors.
- Full Text:
- Date Issued: 2010
Systemic influence on Black South African adolescents' career development : adolescent and parental perspectives
- Authors: Collett, Gary Reece
- Date: 2010
- Subjects: Career development -- South Africa , Teenagers -- Vocational guidance , Adolescence , Parent and child
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:9863 , http://hdl.handle.net/10948/1513 , Career development -- South Africa , Teenagers -- Vocational guidance , Adolescence , Parent and child
- Description: Currently, no career theories exist that sufficiently explain the career development of South Africa’s diverse population groups. Consequently, South African researchers have been entirely dependent on international, western-informed career theories. While such theories have taken on a more ethnocentric complexion in recent times, they remain essentially decontextualised for South Africa. Furthermore, although the influence of family and the significant roles of parents have been theoretically acknowledged as critical influences in adolescent career development, there is still a considerable lack of research in South Africa on this topic. The present study therefore explored the perceptions of systemic influences on adolescent career development from the perspectives of both Black middle-class South African Grade 11 learners and their parents. The research was conceptualised within the Systems Theory Framework (STF) of career development and used its derivative instrument, the My Systems of Career Influences (MSCI, Adolescent). The present study utilised a qualitative research method, using answers derived from the MSCI (Adolescent) booklets to inform semi-structured interviews. The data analysis procedure involved the use of Interpretive Phenomenological Analysis to qualitatively analyse data obtained from the semistructured interviews. Findings revealed a number of influences within the individual system (personality, values, abilities), social system (adolescents’ parents and teachers) and societal-environmental system (financial support, the opportunity to work overseas, geographical location, job availability, and the location of universities) that were acknowledged as having an influence on the career development of South African Black middle class adolescents. Each of these findings were explored and unpacked under the four xii identified Interpretive Phenomenological Analysis (IPA) superordinate themes of Family Dynamics, Great Expectations, The Ghost of Apartheid and Coconuts Fall Far From the Tree. Lastly, the limitations of the present study, as well as recommendations for future research are discussed.
- Full Text:
- Date Issued: 2010
Take my word for it: a new approach to the problem of sincerity in the epistemology of testimony
- Authors: Dewhurst, Therese
- Date: 2010
- Subjects: Sincerity Philosophy Terminology Knowledge, Theory of Honesty
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2707 , http://hdl.handle.net/10962/d1002837
- Description: The epistemological problem of sincerity in testimony is often approached in the following way: We, as a matter of fact, accept utterances as sincere. We do so in the face of knowledge that people lie and deceive,and yet we still count these beliefs as good beliefs. Therefore there must be some reason or argument that we can cite in order to justify our acceptance of the sincerity of the speaker. In this thesis I will argue, contra this, that there is no reason, per se, that justifies our of a speakers sincerity: this is because recognition of the obligation to accept the sincerity is a necessary condition on the possibility of communication and interpretation. In the first three of the thesis I will argue against three of the main approaches to the problem by focusing on what I believe to be the strongest accounts of each: Elizabeth Fricker's reductionism, Tyler Burge's non-reductionism, and Paul Faulkner's trust account of testimony. In the final chapter I will put forward my positive account. I will argue that it is a constitutive rule of language that a speaker be sincere, and then make the further claim, that it is a constitutive rule of interpretation that the hearer take an utterance as sincere. On my account, successful communication does not just depend on a speaker making sincere utterances,but just as importantly,, on the hearer recognising an obligation to take those utterances as being sincere.
- Full Text:
- Date Issued: 2010
Target costing as a strategic cost management tool in the South African motor industry
- Authors: Slater, Michael, M A
- Date: 2010
- Subjects: Target costing -- South Africa , Strategic planning -- South Africa -- Management , Cost accounting -- South Africa -- Standards , Cost accounting -- South Africa , Cost control
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:8974 , http://hdl.handle.net/10948/1094 , Target costing -- South Africa , Strategic planning -- South Africa -- Management , Cost accounting -- South Africa -- Standards , Cost accounting -- South Africa , Cost control
- Description: Traditional cost-accounting approaches have served manufacturers well over a long period, but due to the changing nature of the modern manufacturing environment shortcomings have resulted and are no longer regarded as suitable (Gagne & Discenza 1993: 68). Similarly, Monden and Lee (1993: 22) state that many practitioners and academicians have questioned the effectiveness of standard cost systems, which have been used as the primary cost control measure for the last several decades. Cooper and Slagmulder (1997: 2) point out that in contrast to the conventional cost management techniques, target costing adopts a feed-forward approach. The objective of target costing is to design costs out of products, and not to find ways of eliminating costs after the products enter production. Few firms can afford to ignore such a powerful mechanism to increase profits in today’s highly competitive environment.
- Full Text:
- Date Issued: 2010
The advent of the 'Festivore' an exploration of South African audience attendance in the performing arts at the National Arts Festival
- Authors: Antrobus, Richard Roy
- Date: 2010
- Subjects: Standard Bank National Arts Festival -- Economic aspects , Arts -- Economic aspects , Performing arts festivals -- Economic aspects -- South Africa -- Grahamstown , Arts -- South Africa -- Economic aspects , Arts -- South Africa -- Finance , Arts -- South Africa -- Political aspects , Arts audiences -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2130 , http://hdl.handle.net/10962/d1002362
- Description: In South Africa, the performing arts have contributed to enhancing national identity and distinctiveness despite coming up against weak legislation, policy and infrastructure to support their growth and proliferation (Fredericks, 2005: 9). Coupled with a decline in both government and consumer support and the contradictory disparity between valuing the arts and the funding of the arts, theatre companies can no longer rely on the comfort of external subsidies and financial support. In order to be economically viable and sustainable to ensure their survival, there is an increasing demand for theatre companies to look to novel ways of increasing audience demand for theatre and improving audience attendance. However, instead of risking artistic integrity and the performance product to satisfy the market, this research suggests that promotion and development of theatre at arts festivals provides a platform to access a wider theatre-going public, which therefore facilitates a change in the market focus toward appreciation of the product (production). It explores leading arguments pertaining to the attendance of arts and cultural events, namely, Peterson and Simkus (1992), later updated by Peterson‟s (2005)„omnivore-univore‟ argument. The argument purports cultural consumption as binary in nature: either significant and diverse or limited, if not absent altogether. Supported by a number of case-studies, including Chan and Goldthorpe (2005) and Montgomery and Robinson (2008) and Snowball et al. (2009), the investigation challenges Bourdieu‟s (1984) theory on cultural distinction as well as the homology and individualisation argument. In determining the factors that influence cultural taste and consumer behaviour, including motivators and inhibitors of attendance and a predominant emphasis on audience risk and information asymmetry, the research was placed in a local context, providing an overview of the socio-economic theatre environment in South Africa. It investigated the nature, structure and impact of local festivals (as events) in changing audience demand and theatre attendance. With specific reference to the South African National Arts Festival (NAF) the research notes the effects of Hauptfleisch‟s „eventification‟ phenomenon on univore attenders and therefore expands the omnivore-univore theory to include a new breed of attender: the “Festivore”. A case study explored the “Festivore” hypothesis through empirical research, surveys and face-to-face qualitative interviews and on-seat questionnaire responses by festival attenders. Personal interviews and communication was also carried out with leading experts in the field. The data was then analysed using SPSS 13 electronic statistical analysis programme to determine the socio-demographics and the factors that affect theatre attendance of existing, as well as potential target, theatre audiences at the National Arts Festival The study concluded that South African theatre attenders are generally omnivorous consumers and that, more importantly, there seems to be a shift towards „festivorous‟ consumption. Furthermore, evidence supports the development and proliferation of festivals as a means not only to support and promote the arts in South Africa but, more importantly, to generate new theatre audiences and entrench theatre attendance into South African culture.
- Full Text:
- Date Issued: 2010
The anticancer activity of Cyathula prostrata on two malignant cell lines
- Authors: Schnablegger, Gerald
- Date: 2010
- Subjects: Medicinal plants
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10309 , http://hdl.handle.net/10948/1563 , Medicinal plants
- Description: Plants have always been a source of medicine and are still being used by traditional healers in the rural part of Africa, Asia and India to treat a range of illnesses including cancer. The in vitro anticancer activity of an 80 percent ethanol extract of Cyathula prostrata, an annual branching shrub used by traditional healers in Nigeria to treat cancer was investigated. No previous studies have outlined the possible pathways and mechanisms used by cancer cells when treated with C. prostrata. Dose response analysis was performed to determine the effective cytotoxic concentrations of C. prostrata on HeLa (cervical cancer cell line) and U937 (myelo-monocytic cell line). The IC50 values were 100.8 μg/ml and 64.4 μg/ml for HeLa and U937 cells, respectively. All further experiments were performed using 125 μg/ml C. prostrata extract and 50 μM cisplatin as positive control. With the use of the fluorescent DNA binding dye propidium iodide, the induction of tumour cell death by C. prostrata extract has been linked to cell cycle arrest in the G1 phase at 24 and 48 h. In both cell lines, more than 80 percent of the C. prostrata treated cells were found in the G1 phase after 48 hours of treatment. The annexin V-FITC/PI assay revealed an increase in the percentage apoptotic cells from 4.9 percent to 53.1 percent at 24 h and 8.3 percent to 50.3 percent at 48 h. Since apoptosis induction can occur via a number of different pathways, distinct features were used as markers to investigate the mode of action of this C. prostrata extract. Markers such as activated caspase-8, p21 and cyt-c, were investigated with the aid of fluorescently labelled (FITC) antibodies with analysis using flow cytometry. No change in p21 levels was observed in response to treatment with the extract for up to 48 h. Cell cycle arrest in G1 was therefore not induced by this cyclin-CDK inhibitor. Increase in caspase-8 activation was observed in response to treatment with the extract with no cyt-c release from the mitochondria. The lack of cyt-c release was due to no change in mitochondrial membrane potential, which was investigated with the aid of fluorescent mitochondrial dyes and flow cytometric techniques. Caspase-8 activation is unique to the extrinsic apoptotic pathway. The results from this study therefore show that C. prostrata extract induces apoptosis via the extrinsic pathway and that this activation in independent of the mitochondria. The levels of hTERT, the catalytic subunit of telomerase, were investigated as an additional molecular target for C. prostrata. This was also investigated using FITC labelled antibodies and flow cytometry. A decrease in hTERT levels was observed following C. prostrata treatment. The findings from this study suggest that the extract acts through multiple targets, by inducing: cell cycle arrest in the G1 phase through an unknown mechanism; apoptosis through an extrinsic death receptor pathway and replicative senescence through inhibition of telomerase.
- Full Text:
- Date Issued: 2010
The applicability of the promotion of Administrative Justice Act in review of CCMA arbitration awards
- Authors: Phanyane, Namadzavho California
- Date: 2010
- Subjects: Arbitration (Administrative law) -- South Africa , Arbitration and award -- Law and legislation -- South Africa
- Language: English
- Type: Thesis , Masters , LLM
- Identifier: vital:10219 , http://hdl.handle.net/10948/1282 , Arbitration (Administrative law) -- South Africa , Arbitration and award -- Law and legislation -- South Africa
- Description: South Africa’s employment law has undergone more frequent and dynamic changes than any area of the law, in recent years. The ability of employers and employees to regulate their respective rights and duties vis-à-vis each other by independent agreement has been progressively whittled down by statutory intervention. In so limiting the capacity of parties to the employment relationship to regulate the nature of their relationship, South Africa has followed development in Western industrialised nations. Against this background, the drafters of the Labour Relations Act1 (LRA), as amended, proposed a comprehensive framework of law governing the collective relations between employers and trade unions in all sectors of the economy. The LRA2 created a specialised set of forums and tribunals to deal with labour and employment related matters. It established Bargaining Councils, the Commission for Conciliation Mediation and Arbitration (CCMA), the Labour Court (LC) and the Labour Appeal Court (LAC). It also created procedures designed to accomplish the objective of simple, inexpensive and accessible resolution of labour disputes. In redesigning labour law, the legislature decided that some disputes between employers and employees should be dealt with by arbitrators and others by judges. It is this distinction that resulted in the creation of the CCMA and the Labour Court to perform arbitration and adjudication respectively. The result of adjudication is generally subject to appeal to a higher court. The result of arbitration is generally subject to review. Arbitration was given statutory recognition in South Africa by the Arbitration Act3. That Act provides a framework within which parties in dispute may if they wish appoint their own “judge” and supply him or her with their terms of reference tailored to their needs. With the foregoing in mind, the purpose of this work is the provision of a selection of landmark cases that dealt with the review function of CCMA awards. This selection 1 Act 66 of 1995 as amended comprises of landmark judgments of the different courts of the land. The study uses, as it departure point, legislative framework to elicit the extent to which review is extended to the litigants. Apart from looking at the legislative provisions towards review grounds, reference is made to specific landmark judgments that have an effect on this subject in order to provide a comprehensive and explicit picture of how CCMA arbitration awards may be taken on review. This study focuses on substantive law developed by the Labour Court, High Court, Supreme Court of Appeal and finally the Constitutional Court. This is informed by the very nature and scope of the study because any concentration on procedural and evidentiary aspects of review could lead to failure to achieve the objectives of the study. It looks at specific South African case law, judgments of the courts and the jurisprudence in the field of employment law so that the reader is presented with a clearer picture of recent developments in addressing review of arbitration awards. The concluding remarks are drawn from a variety of approaches used by the authorities in the field of employment law in dealing with review of CCMA arbitration awards and issues for further research are highlighted.
- Full Text:
- Date Issued: 2010
The biology of austroglanis gilli and austroglanis barnardi (siluriformes : austroglanididae) in the Olifants River system, South Africa
- Authors: Mthombeni, Vusi Gedla
- Date: 2010
- Subjects: Catfishes -- South Africa -- Olifants River , Fishes -- South Africa -- Olifants River -- Growth , Freshwater fishes -- Effect of pesticides on -- South Africa -- Olifants River
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5370 , http://hdl.handle.net/10962/d1015222
- Description: Austroglanis gilli and A. barnardi are endemic to the Clanwilliam-Olifants System in the Western Cape, South Africa. The populations of each of these species are considered to be threatened by various anthropogenic activities, which include inappropriate agricultural practice and impacts of alien invasive fish species. The purpose of this thesis was to assess the life-history of these two endangered species in order to contribute to understanding their biology. Such information is vital for the development of strategies for their conservation. Marginal zone and marginal increment analyses from sectioned lapilliar otoliths of both A. gilli and A. barnardi showed a unimodal peak, suggesting a single annulus formation. The oldest specimens of A. gilli and A. barnardi were 12+ and 14+ years, respectively. The growth of A. gilli and A. barnardi was relatively slow and was best described by the von Bertalanffy growth curve as: L, = 131.56(1 - exp(- 0.27(t - 1.18 ))) for male and L, = 113.86(1 - exp(- 0.43(1- 0.74))) for female A. gilli from the Rondegat River. In the Noordhoeks River, growth was L, = 99.67(1 - exp(- 0.53(t - 0.35))) for male and L, = 96.60(1 - exp(- 0.64(t - 0.11 ))) for female A. gilli, and L, =71.02(1-exp(-0.26(1-3.07))) and L, = 69.50(1-exp(-0.36(1 - 1.88))) for male and female A. barnardi, respectively. The average natural mortality for the combined sexes was estimated using catch curve analysis at 0.37 ± 0.12 per year for A. gilli from the Rondegat River, and at 0.71 ± 0.05 and 0.39 ± 0.04 per year for A. gilli and A. barnardi from the Noordhoeks River, respectively. For A. gilli in the Rondegat River, the first maturity was estimated at 3.3 years (97.3 mm SL) for males and 3.1 years (94.3 mm SL) for females. In the Noordhoeks River, the first maturity for A. gilli was estimated at 2.0 years (71.9 mm SL) for males and 1.7 (66.4 mm SL) for females, and for A. barnardi at 2.0 (55.0 nun SL) for males and 2.9 years (58.9 mm SL) for females. Maturity corresponded closely to the asymptotic sizes from the von Bertalanffy curves, suggesting a shift in energy use from somatic growth to gonad development. Macroscopic assessment of the state of gonads, the Ganado-somatic index and histological examinations revealed that both A. gilli and A. barnardi have a single spawning season. The presence of oocytes in different stages of development in each of the ovaries of mature females collected between November and January suggested asynchronous, iteroperous serial spawning. The resorption of yolk was observed from ovaries collected between February and March and no vitellogenic oocyte was visible from ovaries collected between April and August. A similar trend was observed for males, with spermatozoa filling the lumen between November and January and some residual spermatozoa being present in the lumens soon after the breeding season. Spermatocytes and spermatids were dominant in the testes until October. An Index of Relative Importance revealed that A. gilli feeds predominantly on the benthic macroinvertebrate larvae of Ephemeroptera (particularly Baetidae), Diptera (particularly Chironomidae and Simuliidae) and Trichoptera. Austroglanis barnardi feeds predominantly on dipteran larvae (particularly Chironornidae and Simuliidae). Chi square contingency tables showed a significant difference in the dominant prey items of A. gilli and A. barnardi in the Noordhoeks River (X₂= 53.79, d.f. = 4, p > 0.001) and A. gilli between Rondegat and Noordhoeks rivers (x₂ = 34.74, d.f. = 4, p > 0.001). The Spearman's rank correlation test showed no shifts in the diet of A. barnardi from Noordhoeks River and A. gilli from Rondegat River with a change in size and season (p>O.OS). However, there was a shift in the diet of A. gilli from the Noordhoeks River which could suggest a distinct patchiness of benthic macroinvertebrates between the riffle feeding areas used by juveniles and other biotopes used by adults. The occurrence, in stomach contents, of other prey items from a wide variety of taxa and the presence of allochthonous material from the terrestrial environment could suggest an opportunistic feeding guild for both Austroglanis species. The life-history traits of A. gilli and A. barnardi, which are charaterized by slow growth, long life span and low relative fecundity, indicate that both species are relatively precocial and K-selected. The population of a precocial species is relatively stable and if population numbers were to be greatly reduced, they would require a long time to rebuild. An urgent conservation intervention is therefore recommended for Austroglanis spp. so as to maintain the diversity of populations within these species. The creation of protected river reserves and raising public conservation awareness may minimise activities that result in altered river hydrology and the destruction of complex benthic habitats.
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- Date Issued: 2010
The botanical importance and health of the Bushmans estuary, Eastern Cape, South Africa
- Authors: Jafta, Nolusindiso
- Date: 2010
- Subjects: Estuaries -- South Africa , Bushmans river estuary , Estuarine ecology -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10614 , http://hdl.handle.net/10948/1255 , Estuaries -- South Africa , Bushmans river estuary , Estuarine ecology -- South Africa
- Description: The Bushmans Estuary is one of the few permanently open estuaries in the Eastern Cape that is characterized by large intertidal salt marshes. Freshwater inflow to the estuary has decreased as a result of abstraction by more than 30 weirs and farm dams in the catchment. The mean annual run-off is naturally low (38 x 106 m3 y-1) and thus abstraction and reduction of freshwater inflow to the estuary is expected to cause a number of changes. The aims of this study were to determine the current health/status of the estuary based on the macrophytes and microalgae and identify monitoring indicators for the East London Department of Water Affairs, River Health Programme. Changes in the estuary over time were determined from available historical data which were compared with present data. This analysis showed that under normal average conditions freshwater inflow to the estuary is very low, less that 0.02 m3 s-1 most of the time. Under these conditions the estuary is in a homogenous marine state. Vertical and horizontal salinity gradients only form when high rainfall and run-off occurs (> 5 m3.s-1). Salinity gradients from 30.1 PSU at the mouth to 2.2 PSU in the upper reaches were measured in 2006 after a high flow event. However the estuary quickly reverted back to its homogenous condition within weeks after this flood. This study showed that freshwater inflow increased nutrient input to the estuary. Total oxidised nitrogen (TOxN) and soluble reactive phosphorus (SRP) concentrations were higher in August 2006, after the flood, than during the other low flow sampling sessions. TOxN decreased from a mean concentration of 21.6 μM in 2006 to 1.93 μM in February 2009. SRP decreased from 55.3 μM to 0.2 μM respectively. With the increased nutrient availability, the response in the estuary was an increase in phytoplankton biomass. After the 2006 floods the average water column chlorophyll-a was 9.0 μg l-1, while in the low freshwater inflow years it ranged from 2.1 to 4.8 μg l-1. The composition of the phytoplankton community was always dominated by flagellates and then diatoms, with higher cell numbers in the nutrient-enriched 2006 period. Although the water column nutrient data indicated that the estuary was oligotrophic, benthic microalgal biomass (11.9-16.1 μg.g-1) in the intertidal zone was comparable with nutrient rich estuaries. Benthic species indicative of polluted conditions were found (Nitzschia frustulum, Navicula gregaria, Navicula cryptotenelloides). These benthic species were found at the sites where wastewater / sewage seepage had occurred. Benthic diatom species also indicated freshwater inflow. During the high flow period in 2006 the dominant diatoms were fresh to brackish species that were strongly associated with the high concentrations of TOxN and SRP (Tryblionella constricta, Diploneis smithii, Hippodonta cf. gremainii, and Navicula species). During the freshwater limited period of 2008 and 2009 the benthic diatom species shifted to a group responding to the high salinity, ammonium and silicate concentrations. The species in this group were Nitzschia flexa, Navicula tenneloides, Diploneis elliptica, Amphora subacutiuscula and Nitzschia coarctata. Ordination results showed that the epiphytic diatom species responded to different environmental variables in the different years. Most of the species in 2008/2009 were associated with high salinity, temperature, dissolved oxygen, ammonium and silicate concentrations while the response was towards TOxN and SRP in 2006. The dominant species were Cocconeis placentula v euglyphyta in 2006; Nitzschia frustulum in 2008; and Synedra spp in 2009. The average biomass of the epiphytes was significantly lower in May 2008 than in both August 2006 and February 2009; 88.0 + 17.7 mg.m-2, 1.7 + 0.8 mg.m-2, and 61.8 + 14.4 mg.m-2 respectively. GIS mapping of past and present aerial photographs showed that submerged macrophyte (Zostera capensis) cover in 1966 and 1973 was less than that mapped for 2004. Salt marsh also increased its cover over time, from 86.9 ha in 1966 to 126 ha in 2004, colonizing what were bare sandy areas. Long-term monitoring of the health of the Bushmans Estuary should focus on salinity (as an indicator of inflow or deprivation of freshwater), benthic diatom identification and macrophyte distribution and composition (for the detection of pollution input), and bathymetric surveys (for shallowing of the estuary due to sedimentation).
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- Date Issued: 2010
The characteristics and role of informal leaders in work groups : a South African perspective
- Authors: Wienekus, Barend Willem
- Date: 2010
- Subjects: Supervisors, industrial -- South Africa Leadership -- South Africa
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:1166 , http://hdl.handle.net/10962/d1002782
- Description: It has been twenty years since F W De Klerk unbanned the African National Congress. This momentous occasion changed overnight the business landscape in South Africa and the way business were done for many decades. Before and after this crucial moment in South African history, leaders played a significant role in bringing change about as well as managing it. Whether hierarchical or non-hierarchical, leadership manifests itself through all spheres of civilisation. Within any collective, formal as well as informal leadership are always at work and within the environment there always seems to be an individual that appears to hold equal or more influence and sway over the collective. This research investigates the characteristics and role of this individual, the informal leader. In addition, against the melting pot of the diversity of culture, social structures, economics, and demographics in South Africa, the influence of culture on how leadership is being perceived and experienced is also researched. The research is grounded in a post-positivists approach and conducted within a constructivist-interpretative paradigm. A qualitative approach is followed with personal interviews as the method to collect the data from respondents. The interview protocol consists of a combination of questions containing questions of both a quantitative and qualitative nature. Questions of a qualitative nature were open-ended and of an in-depth nature. The research is two pronged. The focus of the research is an Original Equipment Manufacturer (OEM) in the South African Motor Industry and for the primary goal of the research data was collected from employees within work groups of the OEM. The primary research goal investigates the role and characteristics of informal leaders in work groups as seen and experienced by their fellow employees and if there is any congruence with that of the role and characteristics of formal leaders. The study found no fundamental differences between the characteristics and role of formal and informal leaders. The characteristics and role of leaders between different cultures also appear to be the same. For the secondary research goal – determining whether the role and characteristics of informal leaders in work groups could be underpinned in the principles of Ubuntu and if consideration should be given to any cultural differences between leaders and followers by organisational hierarchies – the literature was reviewed in order to reach a conclusion with regards this goal. The literature indicates that culture does affect leadership, especially on how the leadership is executed and experienced in a multicultural society and if ignored, will have a detrimental effect on effective leadership. In order to strive towards achieving maximum productivity, it is imperative that management in South African organisations be aware of the changed dynamic within their organisations as well as on the global stage. The research therefore ends with the practical implications of informal leaders for organisations in South Africa. It is recommended that the importance and contribution of informal leaders within work groups in a multi-culture organisation needs not only to be considered as an element of group leadership, but should be accommodated by the organisation. It is also recommended that organisations recognise the cultural differences between leaders and followers in organisations and the possible consequences if ignored. If the competitive pressures and requirements of globalisation are ignored against the background of Afrocentric expectations and motivational imperatives of the South African workforce, it will result in an ineffective workforce, which will in due course render these organisations uncompetitive and non-sustainable locally and globally.
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- Date Issued: 2010
The child accused in the criminal justice system
- Authors: Brink, Ronelle Bonita
- Date: 2010
- Subjects: Children's rights -- South Africa , Children -- Legal status, laws, etc -- South Africa , Children's rights -- Law and legislation -- South Africa
- Language: English
- Type: Thesis , Masters , LLM
- Identifier: vital:10178 , http://hdl.handle.net/10948/1229 , Children's rights -- South Africa , Children -- Legal status, laws, etc -- South Africa , Children's rights -- Law and legislation -- South Africa
- Description: The high level of crime in South Africa raises the question about the failures of the criminal justice system on the one hand, and South Africa’s social policies on the other. Young people in South Africa can disproportionately be both victims and perpetrators of crime in the Republic of South Africa. The child accused in conflict with the law is dealt with in much the same way as their adult counterparts, as the criminal justice system was designed by adults for adults. South Africa became a signatory to the United Nations Convention on the Rights of the Child 19891(hereinafter referred to as UNCRC) on 16 June 1995. The UNCRC provides a backdrop to section 28 of the Constitution of the Republic of South Africa Act.2 Article 3(1) of the UNCRC provides as follows: “in all actions concerning children, whether undertaken by public or private social welfare institutions, courts of law, administrative authorities or legislative bodies, the best interests of the child shall be primary consideration.” South Africa is therefore according to article 40(3) of the UNCRC obliged to “establish laws, procedures, authorities and institutions specifically applicable to children in conflict with the law”.3 In terms of article 40(1) of the UNCRC “State Parties recognise the right of every child alleged as, accused of, or recognised as having infringed the penal law to be treated in a manner consistent with the promotion of the child’s sense of dignity and worth, which reinforces the child’s respect for the human rights and fundamental freedoms of others and which takes into account the child’s age and the desirability of promoting the child’s reintegration and the child’s assuming a constructive role in society.”4 1 Adopted by the General Assembly resolution 44/25 on 20 November 1989. 2 The Constitution of the Republic of South Africa Act, Act 108 of 1996. Hereinafter referred to as the “Constitution”. 3 South Law Reform Commission Discussion Paper 96. 4 United Nations Convention on the Rights of the Child adopted by the General Assembly resolution 44/25 on 20 November 1989. iv Synopsis 2003 states that “the Ratification of the UNCRC by the South African government in 1995 set the scene for broad-reaching policy and legislative change”.5 The Constitution includes a section protecting children’s rights, which includes the statement that children have the right not to be detained except as a measure of last resort and then for the shortest appropriate period of time, separate from adults and in conditions that take account of his/her age. 6 After being off Parliament’s agenda since 2003, the Child Justice Act7 has recently been reintroduced. The Act aims to ensure consistent, fair and appropriate treatment of the child accused in conflict with the law. The question arises whether the South African Criminal Justice system involving the child accused adequately recognises and protects the interests of the child accused, particularly in view of the present international legal position.
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- Date Issued: 2010
The Coega project: creative politicking in Post-Apartheid South Africa
- Authors: Mtimka, Ongama
- Date: 2010
- Subjects: South Africa -- Politics and government , Industrial development projects -- South Africa -- Port Elizabeth
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:9425 , http://hdl.handle.net/10948/1576 , South Africa -- Politics and government , Industrial development projects -- South Africa -- Port Elizabeth
- Description: This treatise revisits the process of the implementation of the Coega Project and discusses political economic issues which emerge therein locating them in the political economic context of post-1994 South Africa. Based on an in-depth study of the “Coega Story”, and three years of observing the Coega Development Corporation engaging in the political economic space to implement the project, key themes which are relevant in understanding the nature of politics in the country are highlighted and discussed with a view to drawing lessons for future implementers of economic development projects and policy makers. Key discussions in the study include a critical analysis of the symbiotic relationship between politics and development (or broadly the economy) – where emphasis is made about the centrality of politics in implementing economic development projects; the developmental state – where key characteristics of a developmental state are highlighted; the transition from apartheid to democracy and its implications on the nature of political relations post-apartheid; industrial development as a growth strategy and the interplay of social forces in the post- 1994 political economic space. The Coega Project is located within the broader context of the ruling party seeking to advance what is called the second and, perhaps the ultimate task of the liberation struggle, socio-economic liberation. Its strategic fit in that task is discussed critically taking into account paths to industrialisation as they have been observed from Newly Industrialising Countries and South Africa’s attempts at industrialisation before and after 1994.
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- Date Issued: 2010
The design of the extensions to the Nelson Mandela Metropolitan Museum of Art with specific emphasis on the preservation and improvement of the main entrance into St. Georges Park
- Authors: Van Niekerk, Eduard Johannes
- Date: 2010
- Subjects: Art museums -- South Africa -- Port Elizabeth -- Designs and plans , Art museum architecture -- South Africa -- Port Elizabeth -- Designs and plans
- Language: English
- Type: Thesis , Masters , MArch
- Identifier: vital:8155 , http://hdl.handle.net/10948/d1021224
- Description: The city of Port Elizabeth was established as a British colonial town in 1820 when the settlers arrived. With them, they brought ‘civilization’ from Europe, which can be seen in parts of the historic urban structure of Port Elizabeth as well the art that remains. The largest public space of the old city was St. Georges Park. The current museum buildings are part of the collection of British heritage buildings in a surrounding the park. The park is hierarchically located to align with other important places in the urban fabric. Today the park is used by city members as a sporting facility only. Club members of the various sporting facilities such as bowls, tennis, swimming and cricket clubs enjoy these amenities mostly on a Saturday. The park is also home to the famous Duckpond Cricket Pavilion designed by award winning architect John Rushmere. It is the second oldest cricket club in South Africa and has hosted various first events. The museum however has run out of space a few years ago and proposals have been formed by city officials to connect the existing gallery buildings, which would result in the closure of the gateway into the park while also disrupting the general urban flow and rhythm of the city. Finally, any new museum in South African should try to serve our diverse cultures and preserve a heritage whether pleasant or unpleasant. This type building needs to be a new type of place and be an appropriate symbol of our attitudes towards colonial heritage.
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- Date Issued: 2010
The development and implementation of computer literacy terminology in isiXhosa
- Authors: Sam, Msindisi Scara
- Date: 2010
- Subjects: Xhosa language -- Data processing Computer literacy -- South Africa -- Dwesa-Cwebe Computer literacy -- South Africa -- Grahamstown Information technology -- South Africa -- Dwesa-Cwebe Information technology -- South Africa -- Grahamstown Computational linguistics -- South Africa -- Dwesa-Cwebe Computational linguistics -- South Africa -- Grahamstown Information technology -- South Africa -- Dwesa-Cwebe -- Social aspects Information technology -- South Africa -- Grahamstown -- Social aspects Digital divide -- South Africa -- Dwesa-Cwebe Communication in economic development -- South Africa -- Dwesa-Cwebe Communication in economic development -- South Africa -- Grahamstown South Africa-Norway Tertiary Education Development Programme Rhodes University. Dept. of African Languages
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3580 , http://hdl.handle.net/10962/d1002155
- Full Text:
- Date Issued: 2010
The development of a marketing strategy for a tannery waste by-product
- Authors: Mkhonta, Mpendulo Colin
- Date: 2010
- Subjects: Tanneries -- Waste disposal -- Marketing , Waste products -- Marketing
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:8618 , http://hdl.handle.net/10948/1515 , Tanneries -- Waste disposal -- Marketing , Waste products -- Marketing
- Description: Worldwide chromium waste from tanneries is a major environmental concern. A considerable amount of effort is being implemented by tanneries to resolve the environmental concerns. Because of the wide range of chemicals used in tanning, waste treatment is an important issue in the industry. All the tanneries put considerable money and effort into treating their effluent. South African tanneries currently have various methods of disposing of their chrome waste. Most have systems for recycling the waste and disposing of it in municipal waste dumps or it is dumped on the company's own land. Hence the cost of disposal varies widely. Some companies are forced to pay excessive amounts to dispose of their waste at hazardous waste dumps. Others appear to get away by using municipal dumps. Trivalent Chrome (Pty) Ltd offers a solution to the environmental concern by extracting the most dangerous compound in the waste and converting it to a by-product (green chrome oxide). However, the company must be able to then sell of the green chromium oxide. The study seeks to address how the company can market the by-product.
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- Date Issued: 2010
The disparities arising in the policing of consumptive and non-consumptive marine activities
- Authors: Tembo, Danai
- Date: 2010
- Subjects: Marine resources conservation -- South Africa , Fishery law and legislation -- South Africa
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:8649 , http://hdl.handle.net/10948/1383 , Marine resources conservation -- South Africa , Fishery law and legislation -- South Africa
- Description: The South African marine environment is utilised for both consumptive and non-consumptive activities and for those activities to continue sustainably it is important that these activities be monitored and policed. South Africa's environmental legislation is structured to do just that; outlining specific regulations for all consumptive and non-consumptive activities that can be conducted in the marine environment. Some disparities have been observed regarding the policing of consumptive and non-consumptive marine activities, and these disparities were analysed by means of several case studies and semi-structured key informant interviews. Case studies covered both consumptive (abalone poaching and Illegal, Unreported and Unregulated fishing) and non-consumptive activities (the sardine run and tiger shark diving) currently being conduct in the marine environment. Key informant interviews collected opinions from legal practitioners who felt that the legislation was solid but poorly implemented; and non-consumptive operators who felt that the legislation was implemented in a way that made it difficult for non-consumptive and ecotourism activities to thrive. The poor implementation has resulted in a situation which seems to promote consumptive crimes instead of curbing them.
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- Date Issued: 2010
The dynamics of Larval fish and Zooplankton assemblages in the Sundays Estuary, South Africa
- Authors: Sutherland, Kate
- Date: 2010
- Subjects: Marine zooplankton -- South Africa , Zooplankton -- South Africa , Fishes -- Larvae -- South Africa , Estuarine ecology -- South Africa , Estuaries -- South Africa -- Management , Environmental monitoring -- South Africa , Coastal zone management -- South Africa , Estuarine area conservation -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10697 , http://hdl.handle.net/10948/1119 , Marine zooplankton -- South Africa , Zooplankton -- South Africa , Fishes -- Larvae -- South Africa , Estuarine ecology -- South Africa , Estuaries -- South Africa -- Management , Environmental monitoring -- South Africa , Coastal zone management -- South Africa , Estuarine area conservation -- South Africa
- Description: The larval fish and zooplankton assemblages were studied in the permanently open Sundays Estuary on the south-east coast of South Africa, using standard boat-based plankton towing methods. A total of 8174 larval and early juvenile fishes were caught, representing 12 families and 23 taxa. The Clupeidae, Gobiidae and Blenniidae were the dominant fish families. Common species included Gilchristella aestuaria, Caffrogobius gilchristi, Omobranchus woodi, Liza dumerilii, Glossogobius callidus and Myxus capensis. Estuarine resident species (Category I) predominantly in the preflexion developmental stage, dominated the system. A total of 19 zooplankton taxa were recorded. Copepoda dominated the zooplankton community. Dominant species included Pseudodiaptomus hessei, Acartia longipatella, Halicyclops sp., Mesopodopsis wooldridgei, and the larvae of Paratylodiplax edwardsii and Hymenosoma orbiculare. Mean larval fish density showed similar trends seasonally, spatially and across salinity zones, with mean zooplankton density in the Sundays Estuary. Gut content analysis of five larval fish species: Gilchristella aestuaria, Pomadasys commersonnii, Monodactylus falciformis, Myxus capensis and Rhabdosargus holubi, revealed species specific diet and prey selection. Although larval fish diet contained a variety of prey items, guts were dominated by P. hessei, chironomid larvae, Corophium triaenonyx, copepod eggs and insect larvae. Physico-chemical drivers and the interactions between these two plankton communities provide information that enables a more holistic view of the dynamics occurring in the Sundays Estuary planktonic ecosystem.
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- Date Issued: 2010
The E.coli RNA degradosome analysis of molecular chaperones and enolase
- Authors: Burger, Adélle
- Date: 2010
- Subjects: Molecular chaperones , Escherichia coli -- Biotechnology , Polyphosphates , Polyphosphates -- Biotechnology , RNA-protein interactions
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3950 , http://hdl.handle.net/10962/d1004009 , Molecular chaperones , Escherichia coli -- Biotechnology , Polyphosphates , Polyphosphates -- Biotechnology , RNA-protein interactions
- Description: Normal mRNA turnover is essential for genetic regulation within cells. The E. coli RNA degradosome, a large multi-component protein complex which originates through specific protein interactions, has been referred to as the “RNA decay machine” and is responsible for mRNA turnover. The degradosome functions to process RNA and its key components have been identified. The scaffold protein is RNase E and it tethers the degradosome to the cytoplasmic membrane. Polynucleotide phosphorylase (PNPase), ATP-dependent RNA helicase (RhlB helicase) and the glycolytic enzyme enolase associate with RNase E to form the degradosome. Polyphosphate kinase associates with the degradosome in substoichiometric amounts, as do the molecular chaperones DnaK and GroEL. The role of DnaK as well as that of enolase in the RNA degradosome is unknown. Very limited research has been conducted on the components of the RNA degradosome under conditions of stress. The aim of this study was to understand the role played by enolase in the assembly of the degradosome under conditions of stress, as well as investigating the protein levels of molecular chaperones under these conditions. The RNA degradosome was successfully purified through its scaffold protein using nickel-affinity chromatography. In vivo studies were performed to investigate the protein levels of DnaK and GroEL present in the degradosome under conditions of heat stress, and whether GroEL could functionally replace DnaK in the degradosome. To investigate the recruitment of enolase to the degradosome under heat stress, a subcellular fractionation was performed to determine the localization of enolase upon heat shock in vivo. The elevated temperature resulted in an increased concentration of enolase in the membrane fraction. To determine whether there is an interaction between enolase and DnaK, enolase activity assays were conducted in vitro. The effect of DnaK on enolase activity was measured upon quantifying DnaK and adding it to the enolase assays. For the first time it was observed that the activity of enolase increased with the addition of substoichiometric amounts of DnaK. This indicates that DnaK may be interacting with the RNA degradosome via enolase.
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- Date Issued: 2010