The endocannabinoid system in inflammatory bowel system
- Authors: Ababio, Frank James Kweku
- Date: 2014
- Subjects: Inflammatory bowel diseases , Gastrointestinal system , Gastrointestinal system -- Diseases
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10346 , http://hdl.handle.net/10948/d1020338
- Description: Crohn’s disease (CD) and ulcerative colitis (UC) constitute the two major forms of inflammatory bowel disease (IBD), which are disorders of chronic inflammation in the gastrointestinal tract that are associated with significant morbidity and socioeconomic burden. IBD patients with long-standing intestinal inflammation are more prone to developing colorectal cancer (CRC). Until now, none of the existing IBD treatments is able to heal the mucosal ulcerations satisfactorily. The endocannabinoid system (ECS), which comprises of endogenous cannabinoid ligands, their receptors, and metabolic enzymes, has been implicated in gut homeostasis, visceral sensation, inflammation and gastrointestinal motility. Available studies in rodent models of IBD suggest that enhancing the ECS tone may reduce inflammation and improve mucosal integrity. This evidence indicates that the components of the ECS seem well positioned to exert a protective role in IBD and also to offer a great opportunity for therapeutic exploitation. Despite the role of the ECS in the gut, the presence and function of the components of the ECS is not well characterised in human IBD. The primary aim of the study was to investigate the state of the major components of the ECS in human IBD and to establish whether IBD is associated with any changes of the components of the ECS. Cannabinoid CB1 and CB2 receptors, enzymes for endocannabinoid biosynthesis PLC, “LRAT”, NAPE-PLD and DAGL, and endocannabinoid metabolic enzymes FAAH and MAGL were analysed from colonic tissue samples of CD, UC and control patients by reverse transcription quantitative real-time polymerase chain reaction (RT-qPCR) to determine the relative mRNA expression of the above genes. The RT-qPCR analysis showed that the mRNA expression of PLC, LRAT, and NAPE-PLD were unchanged in both CD and UC, whiles DAGL mRNA was decreased in UC but was unchanged in CD. The endocannabinoid degradation enzymes, FAAH mRNA expression was also unchanged in CD but decreased in UC, whereas the mRNA expression of MAGL was significantly decreased in both CD and UC. NAPE-PLD/FAAH and DAGL/MAGL ratios, an estimation of the balance of AEA and 2-AG levels, showed that AEA and 2-AG levels could be increased and unchanged, respectively, in IBD. The mRNA expression of CB1 was significantly decreased in CD and UC whilst CB2 mRNA expression was unchanged in both forms of IBD. The study demonstrated that the components of the ECS which were investigated were present in colonic tissues of both IBD patients and healthy individuals, but they appear to be off balance in CD and UC patients. The decreased CB1 receptors in IBD patients could be an important modifier in the disease and could also provide a possible pathoaetiological mechanism linking IBD and CRC. Although these findings look promising, more studies with larger sample size are required to characterise the components of the ECS in human IBD.
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- Date Issued: 2014
An entrepreneurial framework for new venture property development projects
- Authors: Abrey, Mark Henry Shaw
- Date: 2015
- Subjects: Real estate development -- South Africa , Entrepreneurship -- South Africa , Land subdivision -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:9709 , http://hdl.handle.net/10948/d1020162
- Description: The business of real estate is one of the largest suppliers of employment, and contributes significantly to the gross domestic product of numerous countries worldwide. It is, therefore, imperative that new real estate development entrepreneurs entering the market identify key competitiveness indicators in order to survive and ensure their success within an ever-changing market. However, property development is a complex process and considered to be 'too risky' Consequently, property development entrepreneurs lack the skills and expertise to effectively manage their business enterprises and the associated risks from project inception to completion, and commissioning. The study was conducted by means of a review of the related literature and by conducting an empirical study. The empirical study was conducted using a quantitative statistical approach by distributing research questionnaires to members falling within the sample population. The primary objective of the study was to develop an entrepreneurial framework for perceived success of new venture property development projects. A descriptive survey was conducted among professionals registered with the South African Property Owners Association (SAPOA) and property development practitioners within South Africa. The salient findings suggest that the following variables positively influence the perceived success of new venture property development projects: Entrepreneurial vision; Strategic management; Stakeholders‘ interests; Professional feasibility and viability reporting; Procurement; Communication; Consumer confidence; Risk management; Governance structures; Specialist advice; The entrepreneurial framework, and The project management body of knowledge (PMBOK). Furthermore, the following variables were identified in the empirical framework affecting the perceived success of new venture property development projects: Entrepreneurial Vision; Strategic Management; Stakeholders‘ Interest; Professional Feasibility and Viability Reporting; Procurement; Communication; Consumer Confidence; Risk Management; Governance Structures; Specialist Advice, and The Project Management Body of Knowledge (PMBOK). This study contributed to the South African property development body of knowledge by addressing the challenges faced by inexperienced entrepreneurs entering the property development market. Furthermore, this study aimed to improve the framework utilised by emerging property developers.
- Full Text:
- Date Issued: 2015
Towards measuring corporate sustainability in the Nelson Mandela Bay automotive manufacturing sector
- Authors: Adams, Abulele
- Date: 2015
- Subjects: Sustainability -- South Africa -- Port Elizabeth Sustainable development -- South Africa -- Port Elizabeth
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/18465 , vital:28648
- Description: This study explored the methods available for measuring corporate sustainability and created an instrument to measure corporate sustainability in the Nelson Mandela Bay (NMB) automotive manufacturing sector. The instrument was created based on three components of sustainability which are environment, society and economy. The study went a step further and added a fourth dimension, current trends to design a measuring instrument. The instrument was then applied on participating companies and further refined to improve it. A total of 16 multi-dimensional indicators to measure corporate sustainability were created and applied to 12 companies in the automotive manufacturing sector. The indicators were used to create a composite corporate sustainability index which can be used to compare the corporate sustainability performance of companies. These indicators were created based on theoretical research and fist hand experience observing the automotive manufacturing sector in the NMB. The indicators were applied to companies as a pilot to test whether they are feasible. Following this, the indicators were refined, improved and applied to more companies to measure corporate sustainability performance. The results of the study were the measuring instrument created, the creation of a composite index as well as the application of the instrument on 12 companies to determine whether the instrument was refined enough to detect differences in the corporate sustainability performance of companies. The results are discussed and further recommendations are made for improvements in the creation and application of the instrument to measure corporate sustainability in the NMB automotive manufacturing sector.
- Full Text:
- Date Issued: 2015
The contribution of the trade in medicinal plants to urban livelihoods: a case study of the informal markets in Nelson Mandela Bay Municipality, Eastern Cape
- Authors: Ah Goo, Delia Felecia Stephanie
- Date: 2012
- Subjects: Medicinal plants -- South Africa -- Port Elizabeth , Informal sector (Economics) -- South Africa -- Eastern Cape , Traditional medicine -- South Africa -- Port Elizabeth -- Markets
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10654 , http://hdl.handle.net/10948/d1011601 , Medicinal plants -- South Africa -- Port Elizabeth , Informal sector (Economics) -- South Africa -- Eastern Cape , Traditional medicine -- South Africa -- Port Elizabeth -- Markets
- Description: The commercialisation of natural resources such as medicinal plants is a strategy that is increasingly being employed by poor people in developing countries such as South Africa, as a means of generating an income. Increasing economic hardship and a lack of employment opportunities in the formal sector of the economy has led to many urban dwellers seeking alternative means of meeting their everyday livelihood needs. Although the contribution of natural resources to subsistence economies is widely recognised, there are few studies that have examined the significance of the trade in medicinal plants to the livelihoods of poor and marginalised people. Thirty informal street traders were interviewed to investigate the role of the medicinal plant trade in sustaining the livelihoods of the traders who operate in the informal sector of the Nelson Mandela Bay Municipality, South Africa. The findings of the research indicate that the sale and collection of medicinal plants is an activity which is exploited by people with limited resources, few skills, little or no education and often without any other source of household income. Middle-aged women from impoverished, single income households dominated the trade. Although income from the trade is modest, it contributed substantially to the total household cash income of the traders. Other benefits of the trade included independence and having a sense of purpose in life, as the traders felt that they were not only helping their families but also the wider community. However, without the income from the trade, many of the traders and their families would be destitute and thus the medicinal plant trade is vital to the wellbeing of these people.
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- Date Issued: 2012
Statistical model for risk diversification in renewable energy
- Authors: Ahame, Edmund
- Date: 2013
- Subjects: Renewable energy sources -- Statistics , Diversification in industry
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10564 , http://hdl.handle.net/10948/d1008399 , Renewable energy sources -- Statistics , Diversification in industry
- Description: The growth of the industry and population of South Africa urges to seek new sources of electric power, hence the need to look at alternative power sources. Power output from some renewable energy sources is highly volatile. For instance power output from wind turbines or photovoltaic solar panels fluctuates between zero and the maximum rated power out. To optimize the overall power output a model was designed to determine the best trade-off between production from two or more renewable energy sources putting emphasis on wind and solar. Different measures of risk, such as coefficient of variation (CV) and value at risk (VAR), were used to determine the best hybrid renewable energy system (HRES) configuration. Depending on the investors’ expected returns (demand) and risk averseness, they will be able to use the model to choose the best configuration that suites their needs. In general it was found that investing in a diversified HRES is better than investing in individual power sources.
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- Date Issued: 2013
Evaluating late payment-induced waste in South Africa through lean construction principles
- Authors: Akuffo-Ntow, Eric Ayesu
- Date: 2016
- Subjects: Construction industry -- South Africa -- Finance , Lean manufacturing -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/8867 , vital:26437
- Description: Central to the sustainable and competitive growth of the South African construction industry is a predictable cash flow through on time payment by clients to contractors. However, chronic late payments, a recurring problem in the industry, especially in the public sector, is bringing untold hardship to contractors by derailing their competitiveness and also eroding the trust among the supply chain partners to the extent that some firms end up closing business in the industry. The situation is viewed from the lean construction perspective as an obstacle that is preventing the accrual of the required value to project parties in the construction industry. This research addresses the causes of late payments to contractors and the role of the quantity surveyor (QS) in terms of influencing early payment from a lean construction perspective. A mixed method approach was used for compiling the primary data for the study. Sequentially, one hundred and two (102) quantitative and twelve (12) interview questionnaires were administered to selected contractors and construction professionals working predominantly on public sector projects. The findings revealed that the approval process for evaluation and certification by the client- appointed agent and intermediary institutions is taking longer than contractually allowed, with parties independently undertaking their evaluation prior to the certification date. This is found to be adverse to achieving consensus on the values of the works for authorisation. Other significant barriers are the lack of funds to authorise payment, random auditor general’s documentation changes, lack of administrators’ system integration and capacity to handle cyclical payment processing. Also, contractors have been found to be in default of timeously submitting complete claim documents. It is therefore recommended that the client agents should partner with the contractor in regular design and documentation reviews, arranging the payment process and should also meet jointly to prepare monthly evaluations. In addition, contractors should be mentored from the onset of the project regarding all the necessary documentation and supporting documents that will be required by the client to ensure that payment approvals are not delayed. The payment authori-sation agent’s capacity should be enhanced through training and improved powers as a singular point of control to perform efficiently and their systems and processes should be integrated to ensure that all parties are implementing the same protocols.
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- Date Issued: 2016
Creation of clay flameless burner for vaporizing an insect repellent containing pmd as an active ingredient
- Authors: Akwi, Faith Mary
- Date: 2012
- Subjects: Insect baits and repellents , Montmorillonite
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10383 , http://hdl.handle.net/10948/d1008406 , Insect baits and repellents , Montmorillonite
- Description: Insecticide treated mosquito bed nets, insecticide aerosol sprays, repellent lotions and creams, repellent candles, vaporizable repellent essential oils, mosquito mats and coils are some of the many malaria personal protection tools that are in use. The latter of these measures are the most accessible and affordable options for the rural population in sub-Saharan Africa. It is therefore important to determine how effective these personal protection measures are by determining their ability to efficiently disperse an active ingredient when the protection measure is in use. In this study, a copper II oxide montmorillonite clay burner (CuOMontmorillonite clay burner) was created to vaporize repellent formulations containing various concentrations of p-menthane-3,8-diol (PMD) as the active ingredient with the aim of determining the percentage of the active ingredient that is released into the air and the rate of release. The performance of the CuO-Montmorillonite clay burner was also compared to that of the Lampe Berger fragrance burner (LBFB). In addition to this, the percentage of PMD released from 6 percentage wt PMD candles of diameters 40mm, 69mm and 83mm was determined and compared to that released when the CuO-Montmorillonite clay burner and Lampe Berger Fragrance burner where used to vaporize PMD repellent formulations. It was found that the rate of vaporization of the various PMD repellent formulations vaporized using the Lampe Berger fragrance burner is affected by the mass of PMD present in the repellent formulations. The 6 percentage wt PMD repellent candles released the least percentage of PMD as compared to that released when the CuO-Montmorillonite clay burner and the Lampe Berger fragrance burner were used to vaporize the PMD repellent formulations.
- Full Text:
- Date Issued: 2012
The perceived economic impact of the city of Johannesburg's storm water attenuation policy on private property developers
- Authors: Aldous, Michael Geoffrey
- Date: 2007
- Subjects: Runoff -- South Africa -- Johannesburg , Real estate development -- South Africa -- Johannesburg
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:9668 , http://hdl.handle.net/10948/765 , Runoff -- South Africa -- Johannesburg , Real estate development -- South Africa -- Johannesburg
- Description: Stormwater attenuation policy has, over recent years, become a highly contentious issue for the property development community. Increased urbanisation, locally and internationally, has forced municipal authorities to reconsider the role of stormwater management in this evolving urban landscape. It is within this context that the legislative support and municipal policy for stormwater management in the City of Johannesburg has been explored, particularly in terms of the economic impact on property developers. The research aimed to explore the relationship between stormwater attenuation policy and the economic impact thereof on private property developers. Consideration was given to the cost, risk and time factors of legislative and policy requirements within the development process. Further consideration was given to the physical environment that has brought about current pressures. Based upon research of international issues highlighted in countries with well developed attenuation policy, a questionnaire was constructed to evaluate the response of local private property developers to selected issues as key sub-problems. The responses were tested against the developed set of hypotheses. The research indicated that developers had a generally poor level of knowledge with regard to the stormwater management policy of the City of Johannesburg, as well as the supporting legislative requirements of provincial and national policy documents. The results of the survey also indicated that developers were strongly opposed to the loss of developable area, but indicated a limited financial impact of the current stormwater attenuation policy. The risk inherent in incorporating an attenuation facility within a development was identified as being low with little perceived impact. Developers further indicated that the inclusion of attenuation facilities was seen as a significant contributing factor in the delay, approval and acceptance of new developments in which attenuation facilities were required, while maintenance costs were indicated to be of a low level of importance. Recommendations in response to the research findings included the establishment of detailed policy documentation and support for effective distribution channels in conjunction with industry and public focused information campaigns, improved municipal capacity and a greater level of technical support. A need for additional stormwater research and an increase in the capture of relevant data for GIS purposes was identified.
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- Date Issued: 2007
Investigation of the performance of photovoltaic systems
- Authors: Alistoun, Warren James
- Date: 2012
- Subjects: Photovoltaic power systems -- South Africa , Photovoltaic power generation -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10517 , http://hdl.handle.net/10948/d1008396 , Photovoltaic power systems -- South Africa , Photovoltaic power generation -- South Africa
- Description: The main objective of this study was to investigate the performance of grid integrated PV systems. A data acquisition (DAQ) system was developed to monitor the performance of an existing grid integrated PV system with battery storage. This system is referred to as a grid assisted PV system. A data logger was used together with the inverters built in data logger to monitor environmental and electrical data on a grid tie PV system which was deployed during this study. To investigate the performance of these grid integrated PV systems PV and BOS device characterization was performed. This was achieved by using current voltage curve tracers and the DAQ system developed. Energy yield estimations were calculated referring to the literature review and a meteorological reference for comparison with measured energy yields from the grid tie PV system.
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- Date Issued: 2012
Improving construction planning through 4D planning
- Authors: Allen, Christopher James
- Date: 2007
- Subjects: Construction industry -- Management , Construction industry -- Computer-aided design
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:9698 , http://hdl.handle.net/10948/467 , http://hdl.handle.net/10948/d1011923 , Construction industry -- Management , Construction industry -- Computer-aided design
- Description: Construction Planning will increasingly play a more critical role within the realm of the Built Environment. Existing practices used to plan and communicate the construction process to be undertaken are failing to deliver the desired results for construction companies and clients alike. At a time of unprecedented growth in the industry around the world, which is leading to a general skills shortage, especially in management positions, construction planners are increasingly being asked to deal with more responsibility. As with other industries, technological improvement in the tools at their disposal is one way to address the inadequacies of the present situation. Increasingly, three dimensional design packages are being used to generate construction information which can then be used for quantities calculations, automated manufacturing processes and construction simulation. The latter forms the basis for their use in the process of planning, through new technologies being developed as virtual construction tools or 4D planning, the addition of time to the 3D model environment, but using the elements within the model as the basis for the construction programme. The benefit of using the design information to form the basis of the programme is that the interface tasks and logistical activities, as well as location related constraints, can be identified and then communicated to all levels within the construction team through a time based visual image. The purpose of this study is therefore to establish a scientifically analysed alternative method for the creation, review and delivery of construction programmes. In order to achieve the research objectives, three methodologies have been employed. Firstly, the literature review in the fields of planning including existing methodologies and previous research of 4D related techniques has been analysed. An overview of the perceived weaknesses to current practises and proposed solution will be explored and best case scenarios outlined and further investigated. Secondly, the 51 Lime Street project provides an environment in which the proposed 4D planning techniques have been implemented and the benefits of the process can, through observation / participation methodology, be validated. Thirdly, through interview questionnaires, with Lime St contractors and management, and e-mail questionnaires to a broader sample stratum, data on the ability of the tools, the techniques employed on 51 Lime Street and similar projects have been collated and statistically analysed to validate the reliability and relevance for future implementation. The result of the research will provide management teams with a practical alternative to existing planning methodologies. Construction planners will have alternative technique that can further enhance their role within the project team whilst increasing their ability to communicate the team’s vision to a wider audience, making them and the project more efficient and effective in the process. It has been proposed that clients insist on the use of 3D from the commencement of the design process so that this information can be passed downstream through the construction process and onto facilities management. Planners need to be able to communicate their requirements better and the 4D planning models provide both a more inclusive way of planning alongside a better communications medium in the form of moving images. A picture tells a thousand words.
- Full Text:
- Date Issued: 2007
An architecutre for the effective use of mobile devices in supporting contact learning
- Authors: Alnseerat, Nemr
- Date: 2014
- Subjects: Mobile communication systems in education , Educational technology
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10490 , http://hdl.handle.net/10948/d1020079
- Description: The features and capacities of mobile devices offer a wide range of significant opportunities for providing learning content in workplaces and educational institutions. This new approach of teaching, called mobile learning, allows for the delivery of learning content on the move at any time. Mobile learning supports learning by producing learning content to learners in a modern and acceptable way. The number of mobile learning applications has increased rapidly in educational environments. There are, however, limited mobile learning applications that take advantage of mobile devices to support contact learning in the classroom environment. The aim of this research was to design a mobile learning architecture to effectively support contact learning in the classroom. The researcher investigated the historical and theoretical background of mobile learning and reported these findings. This included an overview of existing mobile learning architectures. After identifying their limitations, the researcher designed the Contact Instruction Mobile Learning Architecture (CIMLA) to facilitate the use of mobile devices in the classroom. The researcher developed the LiveLearning prototype based on the proposed architecture as a proof of concept. He conducted a usability evaluation in order to determine the usability of LiveLearning. The results indicated that the LiveLearning prototype is effective in supporting contact learning in the classroom.
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- Date Issued: 2014
A natural user interface architecture using gestures to facilitate the detection of fundamental movement skills
- Authors: Amanzi, Richard
- Date: 2015
- Subjects: Human activity recognition , Human-computer interaction
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/6204 , vital:21055
- Description: Fundamental movement skills (FMSs) are considered to be one of the essential phases of motor skill development. The proper development of FMSs allows children to participate in more advanced forms of movements and sports. To be able to perform an FMS correctly, children need to learn the right way of performing it. By making use of technology, a system can be developed that can help facilitate the learning of FMSs. The objective of the research was to propose an effective natural user interface (NUI) architecture for detecting FMSs using the Kinect. In order to achieve the stated objective, an investigation into FMSs and the challenges faced when teaching them was presented. An investigation into NUIs was also presented including the merits of the Kinect as the most appropriate device to be used to facilitate the detection of an FMS. An NUI architecture was proposed that uses the Kinect to facilitate the detection of an FMS. A framework was implemented from the design of the architecture. The successful implementation of the framework provides evidence that the design of the proposed architecture is feasible. An instance of the framework incorporating the jump FMS was used as a case study in the development of a prototype that detects the correct and incorrect performance of a jump. The evaluation of the prototype proved the following: - The developed prototype was effective in detecting the correct and incorrect performance of the jump FMS; and - The implemented framework was robust for the incorporation of an FMS. The successful implementation of the prototype shows that an effective NUI architecture using the Kinect can be used to facilitate the detection of FMSs. The proposed architecture provides a structured way of developing a system using the Kinect to facilitate the detection of FMSs. This allows developers to add future FMSs to the system. This dissertation therefore makes the following contributions: - An experimental design to evaluate the effectiveness of a prototype that detects FMSs - A robust framework that incorporates FMSs; and - An effective NUI architecture to facilitate the detection of fundamental movement skills using the Kinect.
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- Date Issued: 2015
A hybrid approach to beach erosion mitigation and amenity enhancement, St Francis Bay, South Africa
- Authors: Anderson, Dylan Rory
- Date: 2008
- Subjects: Beach erosion -- South Africa -- St Francis Bay , Shore protection -- South Africa -- St Francis Bay , Restoration ecology
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10611 , http://hdl.handle.net/10948/d1008192 , Beach erosion -- South Africa -- St Francis Bay , Shore protection -- South Africa -- St Francis Bay , Restoration ecology
- Description: The St Francis Bay beach has experienced chronic erosion over the past three decades. This erosion can largely be attributed to the stabilisation of a large coastal dunefield which contributed +/- 80 percent of the sand supply to St Francis Bay. Stabilisation began in 1975 initially using plant cuttings and followed by the development of the Santareme holiday suburb resulting in complete stabilisation by 1985. Effects were felt from the late 1970‟s and since then the beach has retreated at between 0.5 - 3 m.yr-1. Erosion has encroached on beachfront properties since the early 1990‟s, leading to the placement of 3-4 m high unsightly rock revetments along much of the beach. Where properly maintained these structures have proved successful in protecting the properties behind, however exacerbated erosion of areas in front and adjacent to these structures is evident. Currently no dry beach is present at high tide for most of the year, leading to a significant reduction in beach amenity value. Several technical studies to investigate remediation of this beach erosion problem have been conducted since the early 1990‟s. This study includes investigations into the processes and dynamics of the existing environment and evaluation of the effectiveness and impacts of several elements of a hybrid approach to coastal protection and amenity enhancement for St Francis Bay beach. This proposal incorporated: Multi-Purpose Reefs (MPR‟s) offshore, for coastal protection and amenity enhancement in terms of surfing; beach nourishment with sand from the Kromme Estuary and dune rehabilitation with appropriate native sand binding species. Extensive fieldwork and data collection were conducted, this included: a series of bathymetric surveys; diving surveys and a helicopter flight; sediment sampling; beach profiling and deployment of a wave/current meter. Analysis of these data provided a greater understanding of the existing environment and dynamics of St Francis Bay and provided reliable inputs for numerical modelling. Numerical and physical modelling was conducted to assess the existing processes and conduct MPR design testing. In addition calibrated hydrodynamic modelling of the Kromme Estuary was conducted in order to assess the impacts of sand extraction from the large sand banks within the mouth of the Kromme Estuary for use as beach nourishment. Comparison of bathymetric survey data collected by the author in 2005/06 with survey data collected by the South African Navy Hydrographic Office (SANHO) in 1952 suggest a major loss of sand from the bay, with a volume difference of some 8.8 X 106 m3 calculated. Greater losses were measured between 10-15 m water depths, with shallow areas of +/- 5 m water depth, remaining more stable. This can be attributed to the presence of shallow reef and rocky substrate through much of the bay at this depth range. Monthly RTK GPS survey data from September 2006 to September 2007 indicates a total loss of 40 000 m3 over this period with the greatest losses measured along the northern part of the beach. The greatest losses were measured after large long period waves from a southerly to south-easterly direction occurred in conjunction with equinox tides in mid March 2007. Sediment sampling at over 100 locations within the bay indicated a high percentage of reef (26 percent) and fairly consistent grain size in the fine to medium size class throughout much of the beach, bay and large sand bank within the estuary. While the majority of the South African Coast is exposed to the predominant south westerly winds and waves, St Francis Bay‟s orientation means that waves from a south easterly to easterly direction dominate. The results of the detailed numerical modelling of the hydrodynamics agree with previous calculations and modelling results which concluded that strong unidirectional longshore currents occur along the headland due to the oblique angle of wave incidence and the close to parallel angle of wave incidence along the beach leads to weak longshore currents of variable direction. Erosion along St Francis Bay beach is a result of cross-shore erosion due to large waves from a southerly to easterly direction. Detached breakwaters are the most effective form of coastal protection in these environments and MPR‟s offer additional benefits over traditional breakwater structures. Results of empirical calculations and numerical modelling indicate that the MPR‟s will provide effective coastal protection through the processes of wave dissipation, wave rotation, salient formation and alteration of nearshore circulation. Physical modelling results allowed the MPR design to be assessed and refined in terms of surfing amenity enhancement and construction constraints. In addition numerical modelling results indicate that impacts due to the extraction of up to 600 000 m3 of sand from the lower Kromme Estuary result in highly localised velocity reduction, mainly limited to the extraction areas. The calculated rate of sediment influx into the lower Kromme Estuary indicates that limited extraction, in the order of 20 000 – 40 000 m3 per year, should be sustainable in the long term. Sedimentation of the lower estuary over recent years has had negative recreational and ecological impacts, through reduced navigability and water exchange respectively. Therefore both the estuary and beach systems prove to benefit from this approach. Although not investigated in detail as part of this study, evidence from numerous projects worldwide indicates that foredunes help to trap wind-blown sand on the beach and form a buffer to storm erosion, therefore dune rehabilitation with native sand-binding plant species was recommended as the third element of the proposed remediation of St Francis Bay beach.
- Full Text:
- Date Issued: 2008
Evaluating the training and supply of artisans in the South African construction industry
- Authors: Anugwo, Iruka Chijindu
- Date: 2013
- Subjects: Skilled labor -- South Africa , Skilled labor -- Training -- South Africa , Artisans -- South Africa , Construction industry -- Employees --Training of -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:9672 , http://hdl.handle.net/10948/d1020042
- Description: The study focused on identifying ways in which to improve and increase the quality of training and supply of skilled artisans in the South African construction industry (especially in Gauteng Province) in terms of short and medium term approach. The construction industry is facing a severe skills crisis and this has made it so difficult to recruit competent artisans. This may be as a result of artisans being regarded as the lowest in the hierarchy of construction worker positions. In addition, these artisans warrant less training than those at executive- and managerial levels. This negative attitude towards artisans training has plunged the industry into crisis. Those involved find it difficult to successfully complete projects on time, within budgeted project costs and within the required quality specification due to lack of competent artisans. However, serious attention is required towards enhancing artisan training in the industry. It is imperative and vital to ensure the survival of the industry. The cardinal aim of this research project was to demonstrate a guiding solution towards the skills crisis. Thus, in order to initiate a tremendous change in the skills profile, certain measures are required, e.g. expanding training institutions to local regions; upgrading and aligning facilities in the training institutions to industrial demands and the dissemination of vital information that will ensure the attractiveness of the industry. This will safeguard the construction organisations operating in Gauteng Province. Although the industry is a major player in the economy, there is need for special attention in order to ensure sustainable growth and economic development. The Government, construction industry stakeholders and training institutions personnel should collaborate to salvage the skills crisis by strategically developing programmes (in accordance with industrial requirements) that will benefit prospective learners. The researcher adopted the descriptive- and analytical survey method, which entailed the use of questionnaires and a review of the related literature for gathering relevant data. The methodology used in the research was the quantitative data analysis. The feature findings of the research concluded that the skilled artisans profile is insufficient to meet industry demands. In addition, training institutions and primary- and secondary educational systems are characterized by ninadequacy and incompetency to produce skilled artisans. The situation is exacerbated by the lack of harmonization between the training institutions and the vindustry’s requirements. Furthermore, the majority of the respondents acknowledged that training of their workers is an important aspect to them, but few of these organisations indicated that they make use of formal training institutions such as FET colleges. The recommendation include that all the stakeholders in the construction industry should form collaborations to strategically develop programmes that would upgrade the existing training institutions. This could be done through provision of adequate funds and resources and the dissemination of vital information that is capable to promote the attractiveness of the industry image.
- Full Text:
- Date Issued: 2013
Causes and effects of non-payment of residential property rates in Mahikeng
- Authors: Asianoah, Rexford Kofi
- Date: 2014
- Subjects: Debts, Public -- South Africa -- Mahikeng , Municipal default -- South Africa -- Mahikeng , Public utilities -- South Africa -- Mahikeng , Collecting of accounts -- South Africa -- Mahikeng
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:9674 , http://hdl.handle.net/10948/d1020076
- Description: One of the major sources of income to South African Municipalities is property rates. Income generated from property rates is meant to develop and deliver services to residents living in the said Municipal area. The main aim of the research was to identify the causes and effects of the non-payment of residential property rates, and also to develop workable strategies to maximise the collection of residential property rates in order to ensure developmental growth sustenance, specifically in Mahikeng Municipal area. Related literature was reviewed on the non-financial viability of Municipalities, maintenance of public infrastructure, service delivery and Municipal development plans in establishing the relationship with non-payment of residential property rates. Four hypotheses were set to guide the research with two testing positive with high level of confidence using the chi square method of testing. The research methodology employed in the research was mainly quantitative where the results and findings obtained from the questionnaire were statistically analysed. The research revealed that: The Mahikeng Local Municipality has failed to find the right medium to send rates bills to clients on time, is not taking active responsibility to recover rates debts, does not provide quality service delivery and the reluctance by locals to pay their property rates. The effects thereof, are the inability of the Municipality to deliver effective and efficient services, lack of maintenance of public infrastructure and development in the area. By implementing various options such as email, sms and the post to send rates bills to property owners, by employing different payment options, for example debit orders, transfers, bank deposits and discounts for property owners and embarking on periodic public awareness campaigns in educating the community regarding the importance of payment of property rates could serve as effective mechanisms to address the non-payment of residential property rates faced by the Mahikeng Local Municipality.
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- Date Issued: 2014
Cytokine signalling functions of human soluble IgE receptors in peripheral blood mononuclear cells from normal and hyper-allergic individuals and in B-lymphoblastoid and monocytic cell lines
- Authors: Askew, Sandra Lyn
- Date: 2006
- Subjects: Ligands , Cell receptors , Cellular signal transduction
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10305 , http://hdl.handle.net/10948/455 , Ligands , Cell receptors , Cellular signal transduction
- Description: CD23 is a multifunctional receptor/ligand, found in a variety of cell types, such as human peripheral blood mononuclear cells (PBMCs), B-lymphoblastoid cell lines, mast cells and basophils. It is also found on a variety of haematopoietic cell lines. As the low-affinity receptor for immunoglobulin E (IgE), CD23 plays a role in antigen-presentation and macrophage activation. As a surface molecule cleaved from the cell membrane, soluble CD23 (sCD23) can act as an adhesion molecule and a cytokine. Perturbances of such molecular interactions may lead to various diseases such as allergies and other inflammatory diseases. It has been speculated that elevated levels of sCD23 may be used to bind secreted IgE, thus preventing it from binding to membrane CD23 on haematopoietic cells, preventing B cells from being activated into IgE producing cells. Signal transduction by sCD23 is dependent on cell subsets, ligands and co-factors required for its function. sCD23 plays a direct role in inducing tumour necrosis factor alpha (TNFα), interleukin-1 alpha (IL-1α) and interleukin-1 beta (IL-1β) and soluble IL-1 receptor from activated human monocytes and PBMCs in vitro. Recombinant forms of 25 and 37 kDa human sCD23 were produced by polymerase chain reaction (PCR)-cloning into pET23a, a bacterial expression vector. The proteins were expressed and refolded, followed by purification by gel filtration chromatography. The purified proteins were biochemically characterized to ensure purity and biological activity, by observing the binding to human IgE both in enzyme-linked immunosorbant assay (ELISA) and surface plasmon resonance (SPR) spectroscopy. ELISA showed KD values of 7.23 x 10-9M and 8.12 x 10-9M for the 25 and 37 kDa proteins, respectively. These values were significantly lower than that of Hibbert et al., (2005). SPR data obtained for the 25 kDa CD23 was not of reliable quality but SPR for the 33kDa sCD23 showed a KD of 1.18 x 10-7M, close to that of Hibbert et al., (2005), J. Exp. Med, 202: 751-760. To test the therapeutic potential of the recombinant molecule, a B-lymphoblastoid cell line (Raji), a pre-monocytic cell line (U937), and PBMCs from normal and hyper-allergic individuals were used. All cells showed no change in production of cytokines. It is essential to investigate further cytokine functions and production implicated by recombinant forms of sCD23, as well as binding of sCD23 to CD21 and CD11b/c, and in vivo IgE regulation before a conclusion can be drawn as to whether recombinant sCD23 is a potential therapeutic target against allergic disease.
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- Date Issued: 2006
A statistical evaluation and analysis of mosquito repellent combination
- Authors: Asquith, Ilse Bernadette
- Date: 2004
- Subjects: Mosquitoes -- Control , Insect baits and repellents
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10422 , http://hdl.handle.net/10948/d1015732
- Description: The present product development project was aimed at studying the synergism and/or antagonism amongst various known insect repellent actives with the view to formulating a multi-active repellent product with improved properties when compared to current single-active commercial products. Advanced statistical methods were used to identify synergism between individual active substances and to define a formulation as close as possible to the “ideal” formulation. Several mosquito repellent samples were prepared and sent to the South African Bureau of Standards (SABS) in Pretoria to test for their efficiency in repelling mosquitoes. From the results of the repellency tests of the various active combinations, three actives were identified that showed promising signs of synergism. These actives were then studied in further detail to determine their optimum combination. In addition, it was shown that when using a natural flavourant as promoter and incorporating a slow-release agent into formulations for aerosols and lotions, a product is obtained that gives comparable levels of efficiency to current commercial products, but at much reduced levels of active loading. Accelerated stability tests performed on the final combination of the three actives used in the final formulation showed no adverse reactions over a three-week study. These tests shall be repeated once the final application form (lotion, aerosol, etc) and product packing have been decided.
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- Date Issued: 2004
Construction project manager health and safety interventions towards improving workers' performance
- Authors: Ayessaki, Winn-Yam Houdou
- Date: 2016
- Subjects: Construction industry -- Management -- Health aspects Construction workers -- Health aspects -- South Africa Construction workers -- Safety measures
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/12275 , vital:27050
- Description: Optimum construction worker (CW) performance is required to achieve project delivery within project parameters. It is not always the case as CWs are regularly exposed to hazards, involved in accidents, their productivity is poor, they suffer from ill health, suffer from work-related musculoskeletal disorders (WMSDs) and contractors lack resources to allocate towards H&S. However, the lack or the absence of health and safety (H&S) measures, which the aforementioned depend on, has a negative impact on workers’ performance. Two descriptive surveys were conducted among professional construction project managers (CPMs) registered with the South African Council for Project and Construction Management Professions (SACPCMP) and general contractors (GCs) registered with the East Cape Master Builders Association (ECMBA). Interviews were also conducted with CPMs registered with the SACPCMP residing in the Nelson Mandela Bay metropolitan area. The salient findings include: • Accidents, which occur on construction sites, impact workers’ performance; • Inadequate H&S implementation affects both CW skills and motivation, which in turn affects their performance; • Poor constructability is relevant to H&S and CWs’ skills; • Provision and maintenance of welfare facilities are commonly inadequate and affect workers’ performance, and • Projects do not benefit from the adequate financial provision for H&S. It was concluded that exposure to hazards, poor site conditions, inadequate provision of welfare facilities, WMSDs, and insufficient financial provision for H&S affect workers’ performance by either incapacitating or demotivating them. Recommendations include : CPMs should make better use of their influence on clients; they should improve communication channels between project stakeholders; legislators need to raise awareness regarding H&S and worker welfare, and training and education institutions need to empower workers and professionals with H&S knowledge.
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- Date Issued: 2016
The effectiveness of health and safety service providers' relative to construction
- Authors: Ayesu-Koranteng, Emma
- Date: 2017
- Subjects: Construction industry -- Health aspects -- South Africa Industrial safety -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/15149 , vital:28151
- Description: The construction industry (CI) is well known to be one of the most dangerous industries in South Africa (SA) due to the complex nature of construction activities, advancement in technologies and an aging workforce, emphasising the need for training. Over the past two decades, the industry has come under the spotlight regarding Health and Safety (H&S). The Occupational Health and Safety (OH&S) Act 85 of 1993 and Construction Regulations (CR) 2014 as amended are the statutes that govern the H&S in the construction workplace. These statutes aim to provide minimum guidelines by which all operating in the industry should abide by in order to ensure the safety of all persons at work. A fundamental aspect of the OH&S Act and CR is for construction employers to assess occupational hazards and conduct risk assessments with remedies to mitigate or prevent such risks. Furthermore, employers are compelled by law to ensure that employees are made aware of the risks at the induction stage, in addition to preventative measures associated with their work activities. Therefore, training forms the structure by which H&S in the workplace can be improved. Training in itself is not enough if it is not based on the employees’ needs as assessed. Training needs to be relevant and effective if it is to have a significant effect in the prevention and possible reduction in the number of occupational injuries and fatalities in the CI. A question that led to the basis of this research was why there were such poor H&S practices in the CI when the statutes clearly require the importance of training. This research is aimed at establishing the effectiveness of service providers relative to construction. Service providers offer services such as training, auditing, SHEQ management, and other H&S related matters. Of fundamental importance is that training has a direct or indirect influence on the health and safety (H&S) of employees in the workplace. Thus, this research aims to determine the effectiveness of training offered by these service providers relative to construction. The researcher utilised the quantitative data collection method to collect primary data from a sample surveyed through a questionnaire, whilst collecting secondary data from books, the Internet, professional journals, and articles. The sampled population consisted of service providers, health and safety practitioners, construction managers, supervisors, and workers, all from the Nelson Mandela Bay Municipal Area. The data was analysed quantitatively using the Statistical Package for Social Sciences (SPSS), ANOVA and the one-sample t-test. The literature reviewed and findings of this quantitative research amongst construction personal such as top, senior, middle management (TSMM), and general workers and labourers (GWL) in the Nelson Mandela Bay Municipal area formed the basis of this study. The study reveals that training offered by service providers was indirectly unrelated to construction. Furthermore, the study also showed that management concurred that there was a strong belief that language did not influence their ability to understand the contents of the training, which is mainly provided in English. The group believed that training from service providers were at the correct level. Alternatively, GWL were of the belief that language influenced their ability to understand the training received. The study also indicated that procurement of these service providers were not based on their skills, knowledge and background in construction. This may be attributed to the fact that management are more advanced in terms of education than GWL. Lastly, the study revealed that a significant number of Safety, Health and Environment (SHE) officers are in the process of registering with the South African Council for the Project and Construction Management Professions (SACPCMP), the professional body responsible for the registration of Construction Health and Safety (CH&S) professions. This study will conclude with findings, conclusions, and recommendations that will be valuable to construction companies relative to the services of service providers.
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- Date Issued: 2017
In vitro cytotoxic effects of selected Nigerian medicinal plant extracts on cancer cell lines
- Authors: Baatjies, Lucinda
- Date: 2012
- Subjects: Cancer -- Treatment , Cancer cells , Medicinal plants , Plant extracts , Traditional medicine , Public health
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10316 , http://hdl.handle.net/10948/d1008191 , Cancer -- Treatment , Cancer cells , Medicinal plants , Plant extracts , Traditional medicine , Public health
- Description: Cancer is a disease that imposes a heavy burden on public health and poses a challenge to science. The World Health Organization estimates that 80 percent of people in developing countries of the world rely on traditional medicine for their primary health needs, and about 85 percent of traditional medicine involves the use of plant extracts. This is particularly true in Africa where a large percentage of the population depends upon medicinal plants for health care. Therefore, detailed screening and evaluation of bioactive substances for chemotherapeutic purposes of African plants are urgently warranted. Furthermore, this will serve to validate the efficacy and safety of African traditional medicine. The current study investigated the in vitro cytotoxic effects of 17 ethanolic extracts of the following 16 plants used in traditional anticancer medicine in Nigeria: Sapium ellipticum leaves, Sapium ellipticum stembark, Combretum paniculatum, Celosia trigyna, Pupalia lappacea, Justica extensa, Hedranthera barteri leaves, Alternanthera sessilis, Ethulia conyzoides leaves, Lannea nigritana stembark, Combretum zenkeri root, Combretum molle leaves, Adenanthera parvoniana, Lannea acida, Cyathula achyranthoides, Drymaria cordata, Cyathula prostrata, against HeLa cancer cells. Five of the most promising extracts (Sapium ellipticum leaves, Combretum paniculatum, Celosia trigyna, Drymaria cordata, Cyathula prostrata) were selected for further screening against HT29 and MCF-7 cancer cells. Of the five, the first two were investigated further based on their activities in the screening phase. The S. ellipticum leaf extract yielded IC50 values of 88.60 ± 0.03 and 93.03 ± 0.03 μg/ml against HeLa and MCF-7, respectively. The toxicity was also evaluated on normal cells and an IC50 of 77.66 μg/ml was obtained for peripheral blood mononuclear cells (PBMCs). The IC50 values for proliferating and confluent Chang liver cells were both >125 μg/ml. These results suggest that the extract may be selective for specific cell types. Bio-assay guided fractionation of the S. ellipticum ethanolic extract yielded two active fractions; chloroform and ethyl acetate. Two compounds isolated from the chloroform extract were screened against the three cancer cell lines and found to be inactive. Three compounds were isolated from the ethyl acetate fraction and revealed IC50 values < 62.5 and < 31 μg/ml against MCF-7. Unfortunately these two compounds soon lost activity before any further work could be done on them and work was continued with the crude extract.
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- Date Issued: 2012