An investigation of the sustainability of the Imbewu Project at Phiwe Primary School
- Authors: Maselana, Thobeka
- Date: 2007
- Subjects: Education -- South Africa -- Eastern Cape Sustainable development -- South Africa -- Eastern Cape Project method in teaching -- South Africa -- Eastern Cape School improvement programs -- South Africa -- Eastern Cape -- Case studies Educational change -- South Africa -- Eastern Cape Education and state -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1924 , http://hdl.handle.net/10962/d1007509
- Description: Sustainable development and projects are relatively new terms In the South African context. This study explores these concepts as they relate to a school that is piloting a project in the Eastern Cape. A number of projects have been introduced in disadvantaged schools to redress imbalances of the past. Funders invest a lot of money, but when they leave, schools struggle to sustain these initiatives. This study aims to investigate whether the Imbewu Project, an educational development pilot project meant to improve schools in the Eastern Cape, made provision for long-term sustainability and whether the school sustained the project. Very little research seems to have been conducted on sustainability, especially in South Africa (SA). The study is conducted in the interpretive paradigm. A single case study involving a number of stakeholders at Phiwe Primary School (PPS) was conducted through observations, interviews, focus groups and document analysis. The study found that the action research strategy intended for the project was constrained by the limited time allowed. In addition, the approach did not address processes which are important for sustainability. Also, the cascade approach to learning is not successful in organisations that have not reached the status of being learning organisations. PPS is still struggling to change its culture and therefore one can say that they cannot sustain the changes that are brought by the project. Firstly, they did not involve the parents in most modules as the project suggested. Secondly, some facilitators did not understand the project. Thirdly, although the project provided for monitoring and support, the study found that there was inadequate support from the project team and district officials. There was a shortage of district officials because the Eastern Cape Department of Education did not invest in appointing people that could sustain the project. However, there are areas where the school is doing an outstanding job despite the fact that there was very little support. The school performed well in implementing and sustaining the project in the following areas: learner welfare, community involvement and involvement of staff members in committees.
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- Date Issued: 2007
Anaerobic digestion of fungally pre-treated wine distillery wastewater
- Authors: Melamane, Xolisa L , Tandlich, Roman , Burgess, Jo E
- Date: 2007
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/71740 , vital:29932 , https://doi.org/10.5897/AJB2007.000-2305
- Description: The combination of fungal pre-treatment with Trametes pubescens and anaerobic digestion were tested for the removal of chemical oxygen demand (COD) and phenolic compounds from wine distillery wastewater. The COD removal efficiency after fungal pre-treatment reached 53.3%. During digestion, pH buffering was achieved using CaCO3 and K2HPO4. This provided a stable environment inside digester for efficient and time-independent COD removal. The total COD removal efficiency reached 99.5%, and the system proved able to eliminate shock COD loads, as indicated by the concentrations of sludge and volatile fatty acids. Complex changes of phenolic compounds are suspected in anaerobic digestion system, and are investigated further.
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- Date Issued: 2007
Analysing the effect of FSP on MIG-laser hybrid welded 6082-T6 AA joints
- Authors: Mjali, Kadephi Vuyolwethu
- Date: 2007
- Subjects: Friction stir welding
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9610 , http://hdl.handle.net/10948/563 , Friction stir welding
- Description: Friction Stir Processing (FSP) of aluminium alloys has been used to modify and improve the microstructure and relevant properties of fusion welded aluminium alloys. The effect of FSP on MIG-Laser Hybrid (MLH) welded aluminium alloy 6082-T6 mechanical and microstructural properties has been studied in this research. The FSP process was used on 6mm thick aluminium alloy plates and a tool was designed specifically for FSP, and the effect of varying speeds was analysed before the final FSP welds were made. The effect of FSP was analysed by optical microscopy, tensile, microhardness and fatigue testing. The aim of the study was to determine whether the FSP process has a beneficial influence on the mechanical properties and metallurgical integrity of MIG-Laser Hybrid welded 6082-T6 aluminium alloy with varying gap tolerances. Three welding processes were compared, namely combined Friction Stir Processing on MIG-Laser hybrid process (FSP-MLH), MLH and Friction Stir Welding (FSW) as part of the analysis. (FSP was carried out on MLH components when it was found that FSP is not an entirely complete welding process but rather a finishing process per se.) The aim of this dissertation is to investigate the effects of the FSP process on the weld quality of MLH welded joints and also to compare this to individual processes like FSW and MLH. This investigation was undertaken in order to gain an understanding of the effect of these processes on fatigue performance and microhardness distribution on aluminium alloy 6082-T6 weld joints.
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- Date Issued: 2007
Analysis of fuel consumption reduction potential through the use of an electrically driven air conditioning compressor
- Authors: Marais, Charel
- Date: 2007
- Subjects: Automobiles -- Air conditioning , Electric vehicles -- Power supply , Automobiles -- Fuel systems , Electric automobiles
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9623 , http://hdl.handle.net/10948/774 , Automobiles -- Air conditioning , Electric vehicles -- Power supply , Automobiles -- Fuel systems , Electric automobiles
- Description: The disturbing current situation regarding the world climate has initiated a major wave of urgent developments towards decreasing the overall impact of human activities on the living environment. A major role player in this development is the automobile industry that is inherently connected to pollution of various types, be it air, water or noise pollution. There have been drastic changes not only in the technologies employed in producing vehicles and components, but also in the construction and technologies built into modern automobiles to lessen the overall environmental impact of the industry. Noxious emissions have been decreased, overall efficiencies increased and vehicles are becoming more economical with each new generation. Stricter laws dictate that the level of acceptable vehicle emissions is to be decreased ever further and all manufacturers are developing various possibilities to achieve this. With the emergence of hybrid vehicle technology, there was also a sudden development of different electrical systems that were made viable by the higher onboard voltage systems employed in hybrid vehicles. One of these developments was the electrical air conditioning compressor for use in automobile applications. Although it is designed to operate with a higher voltage than the traditional 12V onboard vehicle systems, it is theoretically possible to incorporate it into a 12V system by making use of a DC-DC converter to step up the supply voltage of the electrical compressor sufficiently to allow for its successful operation. The question therefore arises whether it would be feasible and sensible to employ an electrical air conditioning system in conventional combustion engine vehicles from an overall fuel consumption and vehicle emissions point of view. A modelling approach was taken where an overall vehicle driving simulation was created to represent an average modern production vehicle. The simulation was then extended to include the options of incorporating models for both mechanically and electrically driven air conditioning systems. This provides insight into the influences of the air conditioning system on the vehicle’s overall fuel consumption and an opportunity to compare the influences from the two different systems. This study attempted to provide answers to some of the viability questions regarding the incorporation of electrically driven air conditioning systems into vehicles that use standard 12V onboard voltage systems. It was found that the electrical system has definite potential as a viable replacement option for the conventional system should it be combined with an appropriate alternator and equipped with an efficient control system.
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- Date Issued: 2007
Antjie Krog and the accumulation of ‘media meta‐capital’:
- Authors: Garman, Anthea
- Date: 2007
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/159713 , vital:40336 , DOI: 10.1080/1013929X.2007.9678272
- Description: While Krog's significant body of work in poetry, prose and journalism is undoubtedly central in her trajectory towards international renown, in this essay I explore the dynamics of her “meteoric rise in status”. The news media's role in mediating Krog to the world for nearly 40 years becomes crucial to this investigation. I use a mix of media theory and field theory to illuminate the multi‐faceted and complex relationship Krog has had with the news media and I argue that her acquisition of ‘media meta‐capital’ has played a significant role in her attainment of a unique voice and speaking platform in a postapartheid, public domain in which few white voices, and especially Afrikaner ones, are being heard.
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- Date Issued: 2007
Apprenticing learners in the context of the Grade 10 physical science classroom
- Authors: Gray, Wesley Barclay
- Date: 2007
- Subjects: Science -- Study and teaching (Secondary) -- South Africa. Education, Bilingual -- South Africa Language and education -- South Africa
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1423 , http://hdl.handle.net/10962/d1003304
- Description: The number of African learners who participate and succeed in physical science is recognized to be ‘disturbingly low’. One of the factors attributed to the low levels of enrolment and performance in physical science is language. In this study, teaching and learning through the language of science is examined in the context of the bilingual classroom. A model of analysis is constructed that (1) extends the notion of the language of science to include the mathematical and visual ‘languages’ of science, (2) takes recognition of the manner in which language, content, and values and beliefs construct the science learner, and (3) moves beyond the characterization of teaching and learning according to the dichotomy of the ‘traditional’/ the ‘progressive’. The model of analysis draws upon the central concepts of a sociocultural model of pedagogy, namely the ‘developmental model’. In addition, the model of analysis makes use of Systemic Functional Linguistics to examine teaching and learning at the micro level of classroom interaction. This study reveals the complex nature in which the language, content, and values and beliefs change as a lesson unfolds: teaching and learning through the language of science has been shown in these classrooms to be marked by features of both a ‘traditional’ and a ‘progressive’ model – each of which appears to serve different functions in the overall construction of the science learner. In addition, this study begins to uncover how a ‘successful’ teacher equips his/ her learners in the context of the bilingual physical science classroom: teaching and learning through the language of science has been shown in these classrooms to incorporate complex and varied strategies that depend upon choices made by both the teacher and learners. These findings substantiate the need to understand the challenges teachers and learners face in the bilingual physical science classroom in ways that acknowledge the complexity of the teaching and learning process.
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- Date Issued: 2007
As You Like It: directed by Helen Flax. Mannville, Port Elizabeth. 2007: theatre review
- Authors: Wright, Laurence
- Date: 2007
- Language: English
- Type: text , review
- Identifier: vital:7051 , http://hdl.handle.net/10962/d1007410 , https://journals.co.za/content/iseasosa/19/1/EJC48089
- Description: preprint , This was a stylish, well-conceived production, which made sense and meaning from what is probably Shakespeare’s most delicate, and ‘English’, of comedies. The piece calls for strong ensemble playing, a full stage of equals rather than a few strong parts dominating the story. The Port Elizabeth Shakespearean Festival pulled it off marvelously.
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- Date Issued: 2007
Aspects of delictual liability in pharmacy practice
- Authors: Lewis, Melissa Geane
- Date: 2007
- Subjects: Pharmacy -- Practice Pharmacist and patient Pharmacy -- Social aspects Pharmacists -- Malpractice Pharmacy -- Law and legislation
- Language: English
- Type: Thesis , Masters , LLM
- Identifier: vital:3706 , http://hdl.handle.net/10962/d1005963
- Description: The thesis explores the various instances in which pharmacists may incur delictual liability for harm suffered by their patients or third parties. As such, it is primarily concerned with the field of professional negligence. The work focuses specifically on the wrongfulness, fault and causation enquiries in pharmacy malpractice cases. The discussion is set against the backdrop of the pharmacy profession's shift towards patient-orientated service in recent years and explores whether this change in the profession's social role has had any effect on the legal duties and standard of care to which pharmacists are currently bound. It is argued that, in light of the dangers posed by modern medicines and the extent to which pharmacists are professionally expected to involve themselves in patient care, pharmacists can no longer escape liability simply by accurately dispensing pharmaceutical products. Rather, they are expected to participate actively in avoiding drug-related injury by, for example, providing patient counselling, detecting invalid or erroneous prescriptions and monitoring prescription refills. Although the thesis places particular emphasis on the role of pharmacists in achieving risk management, it also argues that pharmacists are, in very limited circumstances, required to participate in the risk assessment process traditionally thought to fall exclusively into the realm of physicians. It is furthermore demonstrated that pharmacists can incur liability regardless of whether a patient's harm can also be partially attributed to the blameworthy conduct of another healthcare professional. Although the thesis concludes that pharmacists are currently exposed to greater risks of liability than they were in the past, it also shows that plaintiffs who seek damages from pharmacists will usually experience a number of difficulties in establishing liability. In particular, problems are likely to be encountered in satisfying a court as to the presence of factual causation, which is notoriously difficult to establish in drug-related cases.
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- Date Issued: 2007
Assessing management competencies in selected Southern Cape Municipalities
- Authors: Krapohl, Johannes
- Date: 2007
- Subjects: Local government -- South Africa , Core competencies , Performance -- Management
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:8571 , http://hdl.handle.net/10948/797 , Local government -- South Africa , Core competencies , Performance -- Management
- Description: In his 2006 State of the Nation Address, President Thabo Mbeki emphasised the need for the development of managerial competencies and other skills to empower the country’s municipalities to meet the needs of the community (Governance and Administration, 2005). In order to meet the needs of the local community, municipalities need to render effective and efficient services. The lack of relevant managerial competencies adversly influences the municipality’s capacity to deliver the required services. In addition, the uneven distribution of capabilities and capacity across different sections within a municipality also poses a great risk to municipal performance and equitable service provision over the medium term. Notwithstanding progress made to date, service delivery backlogs still exist in key areas that affect the daily lives of the community. Where these backlogs coincide with poor municipal capacity, the result is service failure and a government that is incapable of meeting its goals (Governance and Administration, 2005). The objective of the study is to assess the contemporary management competencies that are required to assist municipal management in addressing the challenges of a dynamic, uncertain and complex Local Government environment. A questionnaire was used to gather the perceptions of 26 senior managers. This sample constituted a response rate of 65 per cent of people employed by municipalities within the Eden District Municipality’s service area. The questionnaires were distributed to the senior managers by means of an identified contact person within each municipality. The empirical findings such as the mean, median, standard deviation and pvalues were calculated by means of MS Excel. The main findings of this research indicated that: • Presently the most developed managerial competencies were selfmanagement, strategic action, planning and administration and communication. • The least developed current competency was global awareness. • The managerial competencies regarded as the most important for the next ten years were planning, administration and strategic action. • Global awareness was regarded as the least important competency for the next ten years. This finding points to the need for developing the global awareness competency to ensure that Municipal Managers are more sensitive to cultural cues and are able to adapt quickly in novel situations.
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- Date Issued: 2007
Assessing program code through static structural similarity
- Authors: Naude, Kevin Alexander
- Date: 2007
- Subjects: Computer networks -- Security measures , Internet -- Security measures
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10478 , http://hdl.handle.net/10948/578 , Computer networks -- Security measures , Internet -- Security measures
- Description: Learning to write software requires much practice and frequent assessment. Consequently, the use of computers to assist in the assessment of computer programs has been important in supporting large classes at universities. The main approaches to the problem are dynamic analysis (testing student programs for expected output) and static analysis (direct analysis of the program code). The former is very sensitive to all kinds of errors in student programs, while the latter has traditionally only been used to assess quality, and not correctness. This research focusses on the application of static analysis, particularly structural similarity, to marking student programs. Existing traditional measures of similarity are limiting in that they are usually only effective on tree structures. In this regard they do not easily support dependencies in program code. Contemporary measures of structural similarity, such as similarity flooding, usually rely on an internal normalisation of scores. The effect is that the scores only have relative meaning, and cannot be interpreted in isolation, ie. they are not meaningful for assessment. The SimRank measure is shown to have the same problem, but not because of normalisation. The problem with the SimRank measure arises from the fact that its scores depend on all possible mappings between the children of vertices being compared. The main contribution of this research is a novel graph similarity measure, the Weighted Assignment Similarity measure. It is related to SimRank, but derives propagation scores from only the locally optimal mapping between child vertices. The resulting similarity scores may be regarded as the percentage of mutual coverage between graphs. The measure is proven to converge for all directed acyclic graphs, and an efficient implementation is outlined for this case. Attributes on graph vertices and edges are often used to capture domain specific information which is not structural in nature. It has been suggested that these should influence the similarity propagation, but no clear method for doing this has been reported. The second important contribution of this research is a general method for incorporating these local attribute similarities into the larger similarity propagation method. An example of attributes in program graphs are identifier names. The choice of identifiers in programs is arbitrary as they are purely symbolic. A problem facing any comparison between programs is that they are unlikely to use the same set of identifiers. This problem indicates that a mapping between the identifier sets is required. The third contribution of this research is a method for applying the structural similarity measure in a two step process to find an optimal identifier mapping. This approach is both novel and valuable as it cleverly reuses the similarity measure as an existing resource. In general, programming assignments allow a large variety of solutions. Assessing student programs through structural similarity is only feasible if the diversity in the solution space can be addressed. This study narrows program diversity through a set of semantic preserving program transformations that convert programs into a normal form. The application of the Weighted Assignment Similarity measure to marking student programs is investigated, and strong correlations are found with the human marker. It is shown that the most accurate assessment requires that programs not only be compared with a set of good solutions, but rather a mixed set of programs of varying levels of correctness. This research represents the first documented successful application of structural similarity to the marking of student programs.
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- Date Issued: 2007
Assessing the duty to exhaust internal remedies in the South African law
- Authors: Madebwe, Tinashe Masvimbo
- Date: 2007
- Subjects: Remedies (Law) -- South Africa Judicial review of administrative acts -- South Africa Administrative law -- South Africa Administrative law -- England Dispute resolution (Law) -- South Africa Justice, Administration of -- South Africa
- Language: English
- Type: Thesis , Masters , LLM
- Identifier: vital:3709 , http://hdl.handle.net/10962/d1007253
- Description: Since the incorporation of the separation of powers doctrine into the South African Constitution, the problem has arisen that, each of the three tiers of government, the Executive, the Judiciary and the Legislature, has sought to protect exclusive jurisdiction over matters that fall within what constitutes that tier's own realm of authority. The effects of this are especially apparent in the field of dispute resolution in administrative law. The administration is predominantly the province of the Executive, and to a lesser extent, the Legislature. Thus, the acceptability of judicial review in dispute resolution and generally, the intrusion by the Judiciary in matters of the administration is perennially questioned and challenged by both the Executive and the Legislature. In this context, the duty to exhaust internal remedies assumes a pivotal role. It offers a compromise, by prescribing qualified exclusion of judicial review as a first port of call for dispute resolution while simultaneously entrusting initial dispute resolution to the administration. Often, this approach yields tangible results, but from a constitutional and fundamental rights perspective, the duty to exhaust internal remedies is problematic. Its exclusion of judicial review goes against, not only the right of access to court in section 34 of the Constitution, but also the rule of law, to the extent that the rule of law allows for the challenging, in court, of illegal administrative action as soon as it is taken. This thesis analyses the constitutionality of the duty to exhaust internal remedies in section 7(2) of the Promotion of Administrative Justice Act by assessing the consistency of section 7(2) of the Promotion of Administrative Justice Act with the right of access to court in section 34 of the Constitution. The thesis initially examines the origins and historical development of the duty to exhaust internal remedies in the English law, and the subsequent adoption of the duty to exhaust internal remedies into the South African common law for the purpose of interpreting and comprehending the duty to exhaust internal remedies as it is appears in section 7(2) of the Promotion of Administrative Justice Act. Ultimately, the study focuses on and identifies the deficiencies in the current approach to the question of the constitutionality of section 7(2) of the Promotion of Administrative Justice Act, and offers suggestions on how the law might be developed.
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- Date Issued: 2007
Assessing the effects of invasive alien species on rural livelihoods: Case examples and a framework from South Africa
- Authors: Shackleton, Charlie M , McGarry, Dylan K , Fourie, Saskia , Gambiza, James , Shackleton, Sheona E , Fabricius, Christo
- Date: 2007
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/181279 , vital:43715 , xlink:href="https://doi.org/10.1007/s10745-006-9095-0"
- Description: The detrimental impacts of invasive alien species (IAS) on ecosystem goods and services and local and regional economies are well documented. However, the use of IAS by rural communities is little understood, and rarely factored into IAS control programmes. Understanding the use of IAS by rural communities and factoring these into cost-benefit models is complex, depending upon a range of local-level attributes such as the time since invasion, abundance, and local-level costs and benefits. This paper reports on two case studies examining the role of IAS in rural livelihoods in the Eastern Cape, South Africa. In both cases, rural communities made widespread consumptive use of the IAS and generally would prefer higher densities, except in certain key localities. Several households traded in IAS products to generate supplementary income. We present a conceptual framework to guide interpretation of these and future case studies, considering attributes such as time since invasion, the competitiveness of the species, and the relative costs and benefits.
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- Date Issued: 2007
Assessing the use of international business strategies among automotive wiring harness manufacturers in the Nelson Mandela Metropole
- Authors: Mears, Michael
- Date: 2007
- Subjects: International trade , International business enterprises -- South Africa , Corporations, Foreign , International economic relations
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:8741 , http://hdl.handle.net/10948/764 , International trade , International business enterprises -- South Africa , Corporations, Foreign , International economic relations
- Description: Since 1994, the opening up of the South African economy has presented South African companies with opportunities to exploit the bigger global market and also with challenges of competing with international companies. Companies must consider both external environmental forces and internal organizational factors before arriving at a suitable international strategy. This treatise explores the wiring harness industry in the Nelson Mandela Bay to determine whether the industry is adopting international strategies in line with globalization, thus ensuring sustained growth and profitability. A literature survey was conducted to discover the main strategies that are used by companies in order to achieve global competitiveness. These strategies were used in conjunction with Porter's (1990) theory of National Competitive Advantage to analyse the wiring harness industry in the Nelson Mandela Bay. Porter's (1990) theory of National Competitive Advantage was used to analyse the competitiveness of the wiring harness industry in the Nelson Mandela Bay. A questionnaire was developed to test the degree to which the wiring harness industry in the Nelson Mandela Bay is in agreement with the findings of the literature study. This information was used to determine whether the wiring harness industry in the Nelson Mandela Bay is following global trends to remain profitable.
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- Date Issued: 2007
Assessment of antibacterial potentials of Garcinia Kola seed extracts and their interactions with antibiotics
- Authors: Sibanda, Thulani
- Date: 2007
- Subjects: Drug resistance in microorganisms , Garcinia , Antibiotics , Medicinal plants
- Language: English
- Type: Thesis , Masters , MSc (Microbiology)
- Identifier: vital:11242 , http://hdl.handle.net/10353/71 , Drug resistance in microorganisms , Garcinia , Antibiotics , Medicinal plants
- Description: The antibacterial potency of the extracts of the seed of Garcinia kola (bitter kola) was investigated in this study against a panel of referenced, environmental and clinical bacterial strains. The killing rates of the active extract as well as their potential for combination antibacterial therapy with standard antibiotics were also elucidated using standard procedures. The aqueous and acetone extracts of the seed were screened for activity against 27 bacterial isolates. The aqueous extract exhibited activity mainly against Gram positive organisms with Minimum inhibitory concentration (MIC) values ranging from 5 mgml-1 – 20 mgml-1, while the acetone extract showed activity against both Gram negative and Gram positive organisms with MIC values ranging from 10 mgml-1 - 0.156 mgml-1. The acetone extract also showed rapid bactericidal activity against Staphylococcus aureus ATCC 6538 with a 3.097 Log10 reduction in counts within 4 hours at 0.3125 mgml-1 and a 1.582 Log10 reduction against Proteus vulgaris CSIR 0030 at 5 mgml-1 after 1 hour. In addition, the aqueous, methanol and acetone extracts of the seeds also exhibited activity against four clinical strains of Staphylococcus isolated from wound sepsis specimens. The MIC values for the aqueous extract were 10 mgml-1 for all the isolates while the acetone and methanol extracts had lower values ranging from 0.3125 - 0.625 mgml-1. The acetone extract was strongly bactericidal against Staphylococcus aureus OKOH3 resulting in a 2.70 Log10 reduction in counts at 1.25 mgml-1 within 4 hours of exposure and a complete elimination of the organism after 8 hours. The bactericidal vi activity of the same extract against Staphylococcus aureus OKOH1 was weak, achieving only a 2.92 Log10 reduction in counts at 1.25 mgml-1 (4× MIC) in 24 hours. In the test for interactions between the acetone extract of the seeds and antibiotics, synergistic interactions were observed largely against Gram positive organisms using the FIC indices, (indices of 0.52 - 0.875) with combinations against Gram negatives yielding largely antagonistic interactions (indices of 2.0 to 5.0). Synergy (≥ 1000 times or ≥ 3 Log10 potentiation of the bactericidal activity) against both Gram negative and Gram positive organisms was detected by time kill assays mainly involving the antibiotics tetracycline, chloramphenicol, amoxycillin and penicillin G. Combinations involving erythromycin and ciprofloxacin consistently gave antagonistic or indifferent interactions. We conclude that the acetone extract of Garcinia kola seeds possess strong bactericidal activities against both Gram positive and Gram negative organisms and can be therapeutically useful in the treatment of bacterial infections including the problematic staphylococcal wound infections. In addition, the acetone extract can be a potential source of broad spectrum resistance modifying compounds that can potentially improve the performance of antibiotics in the treatment of drug resistant infections.
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- Date Issued: 2007
Assessment of antibacterial potentials of Garcinia Kola seed extracts and their interactions with antibiotics
- Authors: Sibanda, Thulani https://orcid.org/0000-0002-6422-2871
- Date: 2007
- Subjects: Drug resistance in microorganisms http://id.loc.gov/authorities/subjects/sh85039709 , Garcinia http://id.loc.gov/authorities/subjects/sh85053063 , Antibiotics http://id.loc.gov/authorities/subjects/sh85005638
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/19236 , vital:43038
- Description: The antibacterial potency of the extracts of the seed of Garcinia kola (bitter kola) was investigated in this study against a panel of referenced, environmental and clinical bacterial strains. The killing rates of the active extract as well as their potential for combination antibacterial therapy with standard antibiotics were also elucidated using standard procedures. The aqueous and acetone extracts of the seed were screened for activity against 27 bacterial isolates. The aqueous extract exhibited activity mainly against Gram positive organisms with Minimum inhibitory concentration (MIC) values ranging from 5 mgml-1 – 20 mgml-1, while the acetone extract showed activity against both Gram negative and Gram positive organisms with MIC values ranging from 10 mgml-1 - 0.156 mgml-1. The acetone extract also showed rapid bactericidal activity against Staphylococcus aureus ATCC 6538 with a 3.097 Log10 reduction in counts within 4 hours at 0.3125 mgml-1 and a 1.582 Log10 reduction against Proteus vulgaris CSIR 0030 at 5 mgml-1 after 1 hour. In addition, the aqueous, methanol and acetone extracts of the seeds also exhibited activity against four clinical strains of Staphylococcus isolated from wound sepsis specimens. The MIC values for the aqueous extract were 10 mgml-1 for all the isolates while the acetone and methanol extracts had lower values ranging from 0.3125 - 0.625 mgml-1. The acetone extract was strongly bactericidal against Staphylococcus aureus OKOH3 resulting in a 2.70 Log10 reduction in counts at 1.25 mgml-1 within 4 hours of exposure and a complete elimination of the organism after 8 hours. The bactericidal activity of the same extract against Staphylococcus aureus OKOH1 was weak, achieving only a 2.92 Log10 reduction in counts at 1.25 mgml-1 (4× MIC) in 24 hours. In the test for interactions between the acetone extract of the seeds and antibiotics, synergistic interactions were observed largely against Gram positive organisms using the FIC indices, (indices of 0.52 - 0.875) with combinations against Gram negatives yielding largely antagonistic interactions (indices of 2.0 to 5.0). Synergy (≥ 1000 times or ≥ 3 Log10 potentiation of the bactericidal activity) against both Gram negative and Gram positive organisms was detected by time kill assays mainly involving the antibiotics tetracycline, chloramphenicol, amoxycillin and penicillin G. Combinations involving erythromycin and ciprofloxacin consistently gave antagonistic or indifferent interactions. We conclude that the acetone extract of Garcinia kola seeds possess strong bactericidal activities against both Gram positive and Gram negative organisms and can be therapeutically useful in the treatment of bacterial infections including the problematic staphylococcal wound infections. In addition, the acetone extract can be a potential source of broad spectrum resistance modifying compounds that can potentially improve the performance of antibiotics in the treatment of drug resistant infections. , Thesis (MSc)-- Microbiology, University of Fort Hare, 2007
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- Date Issued: 2007
Automated estimation and analyses of meteorological drought characteristics from monthly rainfall data
- Authors: Smakhtin, V U , Hughes, Denis A
- Date: 2007
- Language: English
- Type: text , Article
- Identifier: vital:7078 , http://hdl.handle.net/10962/d1009746
- Description: The paper describes a new software package for automated estimation, display and analyses of various drought indices – continuous functions of precipitation that allow quantitative assessment of meteorological drought events to be made. The software at present allows up to five different drought indices to be estimated. They include the Decile Index (DI), the Effective Drought Index (EDI), the Standardized Precipitation Index (SPI) and deviations from the long-term mean and median value. Each index can be estimated from point and spatially averaged rainfall data and a number of options are provided for months' selection and the type of the analysis, including a running mean, single value or multiple annual values. The software also allows spell/run analysis to be performed and maps of a specific index to be constructed. The software forms part of the comprehensive computer package, developed earlier and designed to perform the multitude of water resources analyses and hydro-meteorological data processing. The 7-step procedure of setting up and running a typical drought assessment application is described in detail. The examples of applications are given primarily in the specific context of South Asia where the software has been used.
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- Date Issued: 2007
Bee-hawking by the wasp, Vespa velutina, on the honeybees Apis cerana and A. mellifera
- Authors: Tan, K , Radloff, Sarah E , Li, J J , Hepburn, H Randall , Yang, Ming-Xian , Zhang, L J , Neumann, Peter
- Date: 2007
- Language: English
- Type: text , Article
- Identifier: vital:6941 , http://hdl.handle.net/10962/d1011965
- Description: The vespine wasps, Vespa velutina, specialise in hawking honeybee foragers returning to their nests. We studied their behaviour in China using native Apis cerana and introduced A. mellifera colonies. When the wasps are hawking, A. cerana recruits threefold more guard bees to stave off predation than A. mellifera. The former also utilises wing shimmering as a visual pattern disruption mechanism, which is not shown by A. mellifera. A. cerana foragers halve the time of normal flight needed to dart into the nest entrance, while A. mellifera actually slows down in sashaying flight manoeuvres. V. velutina preferentially hawks A. mellifera foragers when both A. mellifera and A. cerana occur in the same apiary. The pace of wasp-hawking was highest in mid-summer but the frequency of hawking wasps was three times higher at A. mellifera colonies than at the A. cerana colonies. The wasps were taking A. mellifera foragers at a frequency eightfold greater than A. cerana foragers. The final hawking success rates of the wasps were about three times higher for A. mellifera foragers than for A. cerana. The relative success of native A. cerana over European A. mellifera in thwarting predation by the wasp V. velutina is interpreted as the result of co-evolution between the Asian wasp and honeybee, respectively.
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- Date Issued: 2007
Bi-Alexandroff spaces
- Authors: Matutu, Phethiwe P
- Date: 2007
- Language: English
- Type: Article
- Identifier: vital:6782 , http://hdl.handle.net/10962/d1006925
- Description: Bi-Alexandroff spaces are defined as extensions of Alexandroff spaces [1]. Urysohn’s lemma for bi-Alexandroff spaces is used to show that upper and lower cozero sets of bitopological spaces are bi-Alexandroff spaces. An adjunction between bi-Alexandroff spaces and pairwise completely regular bitopological spaces is established.
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- Date Issued: 2007
Bioremediation of trace organic compounds found in precious metals refineries wastewaters: A review of potential options
- Authors: Barbosa, V L , Tandlich, Roman , Burgess, Jo E
- Date: 2007
- Language: English
- Type: Article
- Identifier: vital:6469 , http://hdl.handle.net/10962/d1005798 , http://dx.doi.org/10.1016/j.chemosphere.2007.01.018 , http://www.sciencedirect.com/science/article/pii/S0045653507001026
- Description: Platinum group metal (PGM) refining processes produce large quantities of wastewater, which is contaminated with the compounds that make up the solvents/extractants mixtures used in the process. These compounds often include solvesso, β-hydroxyxime, amines, amides and methyl isobutyl ketone. A process to clean up PGM refinery wastewaters so that they could be re-used in the refining process would greatly contribute to continual water storage problems and to cost reduction for the industry. Based on the concept that organic compounds that are produced biologically can be destroyed biologically, the use of biological processes for the treatment of organic compounds in other types of waste stream has been favoured in recent years, owing to their low cost and environmental acceptability. This review examines the available biotechnologies and their effectiveness for treating compounds likely to be contained in precious metal extraction process wastewaters. The processes examined include: biofilters, fluidized bed reactors, trickle-bed bioreactors, bioscrubbers, two-phase partitioning bioreactors, membrane bioreactors and activated sludge. Although all processes examined showed adequate to excellent removal of organic compounds from various gaseous and fewer liquid waste streams, there was a variation in their effectiveness. Variations in performance of laboratory-scale biological processes are probably due to the inherent change in the microbial population composition due to selection pressure, environmental conditions and the time allowed for adaptation to the organic compounds. However, if these factors are disregarded, it can be established that activated sludge and membrane bioreactors are the most promising processes for use in the treatment of PGM refinery wastewaters.
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- Date Issued: 2007
Bones of contention : contestations over human remains in the Eastern Cape
- Authors: Mkhize, Nomalanga
- Date: 2007
- Subjects: Dead -- Political aspects -- South Africa Human body -- Symbolic aspects Human remains (Archaeology) -- Repatriation Human remains (Archaeology) -- Repatriation -- South Africa -- Eastern Cape Xhosa (African people) -- Social life and customs Eastern Cape (South Africa) -- Social life and customs Eastern Cape (South Africa) -- History
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2597 , http://hdl.handle.net/10962/d1007665
- Description: This thesis examines three contestations involving human remains which have arisen in the Eastern Cape over the past fifteen years. It shows that the value or meaning attached to human remains is constructed through the socio-historical dynamics out of which these contestations arise. The meaning and value of human remains is neither inherent nor neutral. In Ndancama's case, the need for housing in Fingo Village led hundreds of poor residents to settle on the township's Old Cemetery in 1972. Basic material needs trumped concerns for those buried in the cemetery. When the post-apartheid municipality sought to provide sewerage and housing infrastructure for Ndancama in 2003, its development plans were constrained by new heritage legislation which protects historic cemeteries. Residents insisted that their infrastructural needs were of primary importance. In 1993, the unearthing of human remains at the Old Military Cemetery in King William's Town created a thirteen year long saga which was only resolved with the reburial of the remains in 2006. The presence of the remains proved problematic for a number of reasons. Local authorities failed to rebury the remains speedily. The burden to store them fell on the Kaffrarian Museum which came under fire because this was considered unethical in the postapartheid era. The identity of the remains became a bone of contention in 2006 when the new Amathole District Municipality concluded that the remains were those of victims who died in the 1856-57 Great Cattle Killing. The remains and their reburial became symbols of past injustice and present restoration of African heritage. The 1996 quest by 'Nicholas Gcaleka', a 'self-styled' chief and traditional healer, to search for King Hintsa's skull in the United Kingdom provoked unprecedented public engagement with the incomplete narrative on the fate of Hintsa's body. The power to represent history, and the methods through which historical truth is discovered were at the heart of the contestation. Elites such as the Xhosa Royal and the white scientific establishment were considered neither credible nor authoritative on this historical matter. Public support for Gcaleka revealed that many South Africans sought just recompense for colonial injustices.
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- Date Issued: 2007