Flammability of indigenous and invasive alien woody plants in coastal fynbos and thicket
- Authors: Msweli, Samukelisiwe Tholakele , Potts, Alastair J
- Date: 2020
- Subjects: Forest fires -- Environmental aspects , Forest fires -- Prevention and control
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/45875 , vital:39313
- Description: Globally, extreme fires have become more common in wildland-urban interface areas, and more recently, along the southern Cape coast of South Africa. The 2017 Knysna fires prompted greater understanding of the flammability of, and the fire risk posed by, different vegetation groups, which is essential to develop fire risk mitigation strategies. In this study, I experimentally assessed flammability of 30 woody plant species from the vegetation groups indigenous fynbos, thicket, and invasive alien plants (IAPs) that occur along the southern Cape coast. Live plant shoots were sampled across varying fire weather conditions and burnt experimentally to measure flammability in relation to fire weather conditions, fuel moisture, and fuel load. Flammability measures considered were: burn intensity, completeness of burn, time-to-ignition, and the likelihood of spontaneous ignition. I further assessed the flammability of partially dried plant material as a crude proxy for drought effects, to ascertain whether drying of fuels would differentially affect the flammability of the vegetation groups. I used generalized linear mixed-effects models to assess flammability measures in relation to the predictor variables: fire weather, fuel moisture, fuel load, vegetation groups, and species (as a random factor). Results showed that increasing severity of fire weather significantly increased flammability through increasing burn intensity, increasing completeness of burn, increasing the likelihood of spontaneous ignition, and also reducing time-to-ignition. Increasing fuel moisture significantly decreased burn intensity, completeness of burn, and the likelihood of spontaneous ignition. Fuel load significantly increased burn intensity and time-to-ignition. Flammability was highest in IAPs, intermediate in fynbos, and lowest in thicket. IAPs and fynbos showed significantly higher ignitability, and thus present risks under moderate and high fire weather conditions, whereas thicket presents lower risks under low and moderate fire weather conditions. The drying out of fuels considerably increased flammability equally in the three vegetation groups, and by implication, fire risk due to an increase in dead:live ratio. Flammability was furthermore assessed in relation to fuel traits, i.e. the proportion of fine fuels, coarse fuels, and dead fuels, fuel bed porosity, fuel load, and fuel moisture, using multiple regression analysis and stepwise selection of factors. This revealed that fuel moisture was the most important factor affecting flammability in terms of all the flammability measures. Results further showed that the increase in v the proportions of fine fuels increased flammability by increasing completeness of burn. Lastly, vegetation groups were compared (using Kruskal Wallis) in terms of their flammability and fuel traits. I found that fynbos and IAPs exhibited greater flammability on account of higher completeness of burn and more rapid ignition than thicket species, but no clear distinction was evident between fynbos and IAPs. Fynbos’ high flammability was attributed to high proportions of fine and porous fuels. Thicket’s low flammability was attributed to high proportions of coarse and dense fuels. Little distinction in fuel traits could be made between fynbos and IAPs, except that fynbos had a greater proportion of fine fuels. There is a potential risk posed by the IAPs in terms of increased flammability and fire severity, on an indigenous landscape that is invaded. Fire managers need to encourage the prioritization of the management of IAPs that present high flammability as an attempt to reduce fire risk along the southern Cape coast of South Africa.
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- Date Issued: 2020
Development of aptamers against epitopes of the Ebola virus nucleoprotein for future applications in diagnostics
- Authors: Mutombwera , Atherton Tiripano
- Date: 2016
- Subjects: Ebola virus disease Ebola virus disease -- Treatment , Epidemics
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/45931 , vital:39321
- Description: Five different subtypes of the Ebola virus (EBOV) have been described. Either Zaire or Sudan EBOV subtypes has caused all of the EBOV outbreaks to date. The March 2014 Zaire EBOV disease outbreak that ravaged West Africa had a mortality rate of 70%, and resulted in 11 315 deaths. Swift cost effective EBOV detection is required to manage EBOV disease outbreaks as this leads to the interruption of the chain of transmission. Lateral flow diagnostic devices (LFDs) have been designed to provide quick, simple and cost effective diagnosis at the point of care and have great potential at interrupting the chain of EBOV transmission. The target recognition elements used in LFDs are the most important components of an LFD as they determine not only the selectivity and specificity of the device but also the transportation and storage conditions of the devices. Antibodies are the most common biomolecules used as target recognition elements in LFDs. However, the cost of producing antibodies is high and these biomolecules are highly sensitive to changes in the environmental conditions (e.g. temperature, pH and ionic strengths of buffer conditions), which can affect the selectivity and specificity of the LFDs. Aptamers can be used as alternative target recognition elements in LFDs. Aptamers are short single stranded nucleic acid molecules that have the ability to bind to their targets (e.g. whole cells, small molecules, toxins, proteins and peptides) with high affinity and specificity. By replacing antibodies with aptamers, LFDs can be produced that are less expensive, have higher selectivity and specificity. The aim of this study was to generate aptamers against the two highly conserved linear epitope regions (amino acid 421-440 and amino acid 601-620) of the EBOV nuclear protein (NP) using site directed SELEX. Such aptamers can be used as target recognition elements in the development of a LFD for the diagnosis of EBOV infection. Four aptamers that can potentially bind to the linear epitope spanning from amino acid 421 to 440 of the EBOV NP and four aptamers that can potentially bind to the linear epitope spanning from amino acid 601 to 620 of the EBOV NP were identified in this study. An in silico analysis of the predicted secondary structure of the putative aptamers was performed before and after the truncation of nucleotide sequences from the 5’ and 3’ ends of the aptamers to remove excess nucleotide sequences. Although this study did not characterise the interaction between the aptamers and linear epitope regions, the study succeeded in optimising the buffer conditions for future interaction studies using the SPR Biacore 3000 instrument.
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- Date Issued: 2016
Resolving the service delivery backlog at the Eastern Cape Department of Human Settlements
- Authors: Hlamandana, Zukiswa
- Date: 2016
- Subjects: Project management -- South Africa -- Eastern Cape , Public administration -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/5303 , vital:20831
- Description: The purpose of this study is resolving the service delivery backlog at the Eastern Cape Department of Human Settlements. The problem of service delivery backlogs is not one unique to South Africa but a problem faced by many developing nations. South African government in all spheres still faces a challenge of creating the good life for its citizen, even more on local Municipality as they are government closest to the people and interacts more closely with communities. It is two decades since South Africa became a democratic state and despite promises and efforts to improve service delivery to the public there still exist backlog in service delivery. In order to address the research problem and to fulfil the research objectives, an in-depth literature study was done on the current state and the role of the Department of Human settlements as well as the current backlog facing the department. Housing process and procedures, challenges, policies, finance, factors influencing housing allocation and delivery were also reviewed. Empirical studies were also performed by means of questionnaires with the community and officials in the Eastern Cape Department of Human Settlements. The literature and empirical study made it possible to identify causes, challenges and impact of service delivery backlog and to recommend possible solutions for resolving service delivery backlogs. These recommendations should be of value to the department and the country as a whole. In this study research methodology was focused on the research design, target population of study, sampling design and procedures, data collection instrument, data collection procedures, data presentation, analysis and interpretation. The major findings were identified in the study such as poor workmanship, delays in procurement processes, illegal acts, vandalism, poor planning, finance, project management and quality assurance. The study also offers recommendations such as revising procurement policy, source more funds from National, employ more qualified staff, involve community and all stakeholders in decision making in order to address the service delivery backlog successfully .All kinds of approaches that the government needs to employ in order to also improve its performance of delivering service to the public in South Africa were determined.
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- Date Issued: 2016
The influence of financial market development on economic growth in Brics countries
- Authors: Ruzive, Tafadzwa Mutsvedu
- Date: 2015
- Subjects: Financial services industry -- Marketing , Economic development -- BRIC countries
- Language: English
- Type: Thesis , Masters , MPhil
- Identifier: http://hdl.handle.net/10948/6594 , vital:21123
- Description: The debate about the influence of financial market development on economic growth has been ongoing for more than a century. Since Schumpeter (1912) wrote about the happenings on Lombard Street, right up to the economists of today, there is growing interest into how financial market development affects economic activity and hence economic growth. With economic growth gaining prominence in respect of development discourse, inquiry into the finance-growth nexus has grown rapidly. The latest advances of the finance-growth nexus show a positive relationship between financial market development and economic growth. In this regard, little research has been done globally pertaining to most recent economic developments, especially concerning the BRICS economies. This research investigates the influence of financial market development on emerging economies, BRICS and non-BRICS and to determine whether the openness of financial markets in BRICS economies contributed to higher growth trajectories compared to their non-BRICS counterparts. The research utilises the Generalised Method of Moments and an extended endogenous growth model to estimate the influence of a set of financial market indicators. The study found that higher levels of credit to the private sector and financial depth in the BRICS economies contributed to the higher levels of economic growth experienced in the BRICS compared to non-BRICs emerging economies.
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- Date Issued: 2015
Factors affecting the retention of employees in auditing firms
- Authors: Axon, Kerry
- Date: 2012
- Subjects: Employee retention -- South Africa -- Port Elizabeth , Labor turnover -- South Africa -- Port Elizabeth , Auditing -- South Africa , Job satisfaction -- South Africa -- Port Elizabeth
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:9408 , http://hdl.handle.net/10948/d1015728
- Description: The twenty first century has identified knowledge, as opposed to labour, raw materials or capital, as the key resource required by firms. This has created a shift of ownership in relationships between employees and employers since employees own the tools of production through the knowledge they hold (Kinnear & Sutherland, 2000). The employment relationship is undergoing fundamental changes due to international competition, de-regularisation and globalisation which have major implications for attraction, motivation and retention of talented employees (De Vos & Meganck, 2009). Organisations face great challenges and intense competition with almost all strategies being easily replicable by competitors. This has led organisations to begin realising that people are in fact the only real differentiator that can gain the organisation competitive advantage (Munsamy & Bosch Venter, 2009). Turnover of employees costs South Africa millions of rands per annum through decreased productivity, increased accidents and quality problems. Specifically, loss of knowledge workers are identified through costs of hiring and training new employees, loss of institutional knowledge, lower office morale, loss of talent and customer dissatisfaction. It is therefore essential to understand the reasons why employees leave organisations in order to discover how to retain them (Mendes & Stander, 2011; Gaylard, Sutherland & Viedge, 2005). Employee turnover can have several negative consequences. It can be difficult to replace the departed employees and the cost of replacing employees can be exhaustive. Remaining employees can be left feeling demoralised from the loss of valued co-workers and work patterns can be disrupted until replacements are found (Newstrom and Davis, 1997). Bilal, Zia-ur-Rehman, and Raza, (2010) add to this list of negative consequences of turnover as turnover can increase recruitment and training costs, loss of productivity as projects lose continuity, interruption of key activities, increase in mistakes made, or even hiring the wrong person for the position.
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- Date Issued: 2012
An analysis of strategies used to manage conflict at Volkswagen of South Africa
- Authors: Conybeare, Gaily
- Date: 2008
- Subjects: Volkswagen of South Africa (Firm) , Conflict management -- South Africa , Motor vehicle industry -- South Africa -- Port Elizabeth
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:8743 , http://hdl.handle.net/10948/762 , Volkswagen of South Africa (Firm) , Conflict management -- South Africa , Motor vehicle industry -- South Africa -- Port Elizabeth
- Description: This research study addresses the problem of determining the strategies that can be used by Internal Audit at Volkswagen of South Africa to manage conflict effectively. To achieve this objective a comprehensive literature study was performed to determine the views on conflict and evaluate the various conflict models. The study also included the reasons for and sources of conflict and the effects of conflict on the performance and controls within VWSA. The identification of conflict management strategies and subsequent conflict management styles were revealed by the literature study. Various discussions from different authors on how to resolve conflict situations are also discussed. The literature review serves as a model in the development of a guideline for VWSA Internal Audit team and management to manage conflict. Senior Management, middle management and staff from various departments within VWSA were requested to complete a questionnaire in order to determine the strategies and effectiveness of these strategies used by Internal Audit to manage conflict. The questionnaire was developed in accordance with the findings from the research. A pilot study was conducted to evaluate the relevance of the study to the problem questions and to evaluate whether the questionnaire will be easily understood. The answers of the respondents were analyzed and compared to the findings of the literature study. The information obtained from the literature study and from the respondents resulted in various recommendations and conclusions.
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- Date Issued: 2008